CN207021683U

CN207021683U - A kind of electric energy conversion of new multiport and switching system

Info

Publication number: CN207021683U
Application number: CN201720294182.7U
Authority: CN
Inventors: 冯伟忠
Original assignee: Shanghai Shenneng Electric Power Technology Co Ltd
Current assignee: Shanghai Shenneng Electric Power Technology Co Ltd
Priority date: 2017-03-24
Filing date: 2017-03-24
Publication date: 2018-02-16
Anticipated expiration: 2027-03-24

Abstract

A kind of electric energy conversion of new multiport applied to thermal power plant and switching system, the frequency and/or voltage of at least one connection end can be adjusted by energy converter, and electric energy is controlled to be flowed between the auxiliary bus bar of different frequency, or, electric energy can be controlled to be flowed in different frequency and can control electric energy between the auxiliary bus bar of identical frequency, reduce and even eliminate restriction loss, give full play to the performance of variable-frequency power generation unit, lifting system whole efficiency, simultaneously by adjusting energy converter difference connection end frequency, the motor of the station-service subsidiary engine of different bussed supplies can be made to operate in the demand of different frequency in synchronization, so as to reduce energy consumption and create bigger economic benefit, in addition by the method for the motor start-up and switching that improve station-service subsidiary engine, the flexibility of raising system overall operation mode.

Description

Novel electric energy conversion and switching system of multiport

Technical Field

The utility model relates to a novel electric energy conversion and switched systems of multiport can control the electric energy to flow between the station-service generating line of different frequencies in thermal power factory, perhaps, can control the electric energy again and can control the electric energy to flow between the station-service generating line of same frequency at different frequencies to can help the motor start-up and/or the switching of the station-service auxiliary engine of thermal power factory.

Background

Energy conservation and emission reduction are external requirements of the nation and the society on a thermal power plant and internal requirements of the thermal power plant on cost reduction, profit improvement and social responsibility fulfillment, so that the thermal power plant actively excavates internal potential, performs energy-saving reconstruction and innovative design, or adopts new technology and new equipment to reduce plant power consumption and improve the economical efficiency of the power plant in thousands of ways. The energy-saving innovative technology which is successfully implemented at present is that a variable frequency generator set is built by utilizing an extraction steam pump, a waste heat pump or a water supply pump, and a station auxiliary system is supplied with power in a centralized variable frequency mode through a station bus which is built in a matched mode.

However, the existing centralized variable-frequency power supply technology also has certain disadvantages: one aspect is that throttling losses are generated. The expression is as follows: in the first situation, because the power-steam source pressure characteristic of the small steam turbine is inconsistent with the power-rotating speed characteristic of the motor of the auxiliary plant machine, when the load of the main steam turbine generator set is reduced by a certain power, the air quantity and flow required to be provided by the auxiliary plant machine participating in the centralized frequency conversion are reduced along with the reduction of the air quantity and the flow, and the rotating speed is reduced along with the reduction of the air quantity and the flow, and the power of the motor of the auxiliary plant machine is reduced approximately in a cubic relation along with the reduction of the rotating speed on the basis of the characteristic that the power and the rotating speed are changed in a cubic relation; when the load of the main steam turbine generator set is reduced, the pressure of the extraction steam source of the main steam turbine used by the small steam turbine is reduced along with the load, the power of the small steam turbine is reduced approximately in a one-time relation along with the pressure reduction of the steam source under the original opening degree of the steam inlet adjusting valve, namely, the power change of the motor of the auxiliary plant machine participating in the concentrated frequency conversion is far more remarkable than the power change of the small steam turbine. In order to match the power imbalance between the main steam turbine generator set and the auxiliary steam turbine generator set and meet the power and frequency required by the motor of the auxiliary plant auxiliary machine under the working condition of the main steam turbine generator set, the opening degree of a steam inlet adjusting valve of the small steam turbine is adjusted to help adjust the operating pressure of the small steam turbine so as to achieve the purpose of adjusting the rotating speed and the output power of the small steam turbine, and therefore throttling loss is generated.

In the second case, throttling loss is also generated due to design margin of the extraction steam source itself of the small steam turbine or adjustment of the operation mode. Generally, the power corresponding to the steam source pressure designed by the small steam turbine is greater than the sum of the powers of the motors of the auxiliary plant machines participating in the concentrated frequency conversion, namely, the power is balanced and the frequency required by the motors of the auxiliary plant machines is met by adjusting the opening degree of a steam inlet adjusting valve of the small steam turbine; in addition, due to the requirements of an operation mode or frequency conversion equipment maintenance and the like, the motor of the auxiliary plant machine participating in the centralized frequency conversion can be supplied with power by a power frequency auxiliary plant system, the power of the small steam turbine can be mismatched with the sum of the power of the actually carried load, and the power and the frequency required by the motor of the auxiliary plant machine can be balanced by adjusting the opening degree of a steam inlet adjusting valve of the small steam turbine. In addition, when the circulating water temperature of the small steam turbine is reduced, the corresponding exhaust pressure is reduced, the enthalpy drop of the steam is increased, and the output power is increased. At the moment, the opening degree of a steam inlet regulating valve of the small steam turbine is also required to be regulated to balance power and meet the frequency required by a motor of the auxiliary machine for plant use. In both cases, throttling losses occur.

On the other hand, the existing centralized variable-frequency power supply technology restricts the flexibility of the operation mode of the system, and the starting and switching of the motor of the auxiliary machine for the factory is limited. The expression is as follows: generally, a motor of the auxiliary machine for factory use is directly started under a power frequency working condition, and in the starting mode, the starting current is large and can generally reach 4-7 times of rated current, the service life of the motor can be shortened, other equipment on the same bus is greatly influenced, and the requirement on system capacity is high. The motor of the auxiliary machine cannot be switched under the frequency conversion working condition.

Therefore, those skilled in the art are dedicated to develop a novel multi-port electric energy conversion and switching system applied to a thermal power plant, which can adjust the frequency and/or voltage of at least one connection end, and control electric energy to flow between service buses with different frequencies, or can control electric energy to flow between service buses with different frequencies and the same frequency, so as to reduce or even eliminate throttling loss generated by adjusting the opening of a steam inlet adjusting valve of a small steam turbine, so that the power of the small steam turbine is correspondingly increased, the performance of a variable frequency generator set is fully exerted, the overall efficiency of the system is improved, and thus the service power rate directly supplied by a main steam turbine generator set is reduced, and greater economic benefits are created. Meanwhile, the system and the method can change the starting and/or switching method of the motor of the auxiliary machine for the factory so as to improve the flexibility of the integral operation mode of the frequency conversion system.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention is directed to a multi-port power conversion and switching system with low cost, reliable operation and relatively simple system.

The utility model provides a 1 st novel electric energy conversion and switched systems of multiport includes No. 11 mill buses, No. 22 mill buses, No. 24 mill buses, variable frequency generator, an at least motor of 51 mill auxiliaries, an at least motor of 52 mill auxiliaries, drive variable frequency generator sends the little steam turbine of the alternating current that the frequency can change, the admission regulating valve of control little steam turbine admission volume size, power frequency mill power system, variable frequency generator provides the electric energy to No. 11 mill buses. The frequency and/or voltage of at least one connecting end can be adjusted (the adjusting method can be that the frequency and the voltage are adjusted simultaneously, or the frequency is adjusted independently and then the voltage is adjusted independently, or the voltage is adjusted independently and then the frequency is adjusted independently, or the frequency or the voltage is adjusted independently and then the frequency and the voltage are adjusted simultaneously, etc.), and the electric energy is controlled to flow between the service buses with different frequencies, or the electric energy converter which can control the electric energy to flow between the service buses with different frequencies and the same frequency comprises a No. 61 connecting end, a No. 62 connecting end and a No. 64 connecting end, the No. 61 connecting end of the electric energy converter is electrically connected with the No. 11 service bus, the No. 62 connecting end of the electric energy converter is electrically connected with the No. 22 service bus, and the No. 64 connecting end of the electric energy converter is electrically connected with the No. 24 service bus, the connection end side No. 62 of the power converter and the connection end side No. 64 of the power converter can operate at different frequencies, such as: the running frequency of the No. 22 factory bus is 50Hz, and the running frequency of the No. 24 factory bus is 40 Hz; for another example: the running frequency of the No. 22 factory bus is 44Hz, and the running frequency of the No. 24 factory bus is 41 Hz; and the like. The motor of the auxiliary machine for factory service No. 51 is electrically connected with the bus for factory service No. 11, the motor of the auxiliary machine for factory service No. 51 is electrically connected with the bus for factory service No. 22, the motor of the auxiliary machine for factory service No. 52 is electrically connected with the bus for factory service No. 11, the motor of the auxiliary machine for factory service No. 52 is electrically connected with the bus for factory service No. 24, the power frequency system for factory service is electrically connected with the bus for factory service No. 22 and/or is electrically connected with the bus for factory service No. 24, and the electrical connection relation can be in two.

The utility model provides a 2 nd novel electric energy conversion and switched systems of multiport include No. 11 mill buses, No. 13 mill buses, No. 22 mill buses, No. 24 mill buses, variable frequency generator, an at least motor of 51 mill auxiliary engine, an at least motor of 52 mill auxiliary engines, drive variable frequency generator sends the little steam turbine of the alternating current that the frequency can change, the admission regulating valve of control little steam turbine steam admission size, power frequency mill power consumption system, variable frequency generator provides the electric energy to No. 11 mill buses and No. 13 mill buses. The frequency and/or voltage of at least one connecting end can be adjusted (the adjusting method can be that the frequency and the voltage are adjusted simultaneously, or the frequency is adjusted independently and then the voltage is adjusted independently, or the voltage is adjusted independently and then the frequency is adjusted independently, or the frequency or the voltage is adjusted independently and then the frequency and the voltage are adjusted simultaneously, etc.), and the electric energy is controlled to flow between the service buses with different frequencies, or the electric energy converter which can control the electric energy to flow between the service buses with different frequencies and the same frequency comprises a No. 61 connecting end, a No. 62 connecting end and a No. 64 connecting end, the No. 61 connecting end of the electric energy converter is electrically connected with the No. 11 service bus, the No. 62 connecting end of the electric energy converter is electrically connected with the No. 22 service bus, and the No. 64 connecting end of the electric energy converter is electrically connected with the No. 24 service bus, the connection end side No. 62 of the power converter and the connection end side No. 64 of the power converter can operate at different frequencies, such as: the running frequency of the No. 22 service bus is 43Hz, and the running frequency of the No. 24 service bus is 48 Hz; for another example: the running frequency of the No. 22 factory bus is 50Hz, and the running frequency of the No. 24 factory bus is 42 Hz; and the like. The motor of the auxiliary machine for factory service No. 51 is electrically connected with the bus for factory service No. 11, the motor of the auxiliary machine for factory service No. 51 is electrically connected with the bus for factory service No. 22, the motor of the auxiliary machine for factory service No. 52 is electrically connected with the bus for factory service No. 13, the motor of the auxiliary machine for factory service No. 52 is electrically connected with the bus for factory service No. 24, the power frequency system for factory service is electrically connected with the bus for factory service No. 22 and/or is electrically connected with the bus for factory service No. 24, and the electrical connection relation can be in two.

The electrical connection can be connected directly by a cable, a closed bus, or the like, or can be connected by a combination of a cable, a closed bus, and a device for connecting or disconnecting the cable and the closed bus to or from the control circuit. The connection and disconnection of the electrical connection can be realized by means of a device for controlling the connection or disconnection of the circuit and the like. The device for controlling the circuit connection or disconnection can be a circuit breaker, a circuit breaker handcart, a switch cabinet, an isolating switch, a fuse, a contactor or a combination of the devices.

The power frequency station power system is characterized in that station power refers to electric energy used by a power plant in the production process, for example, a large number of station auxiliary machines dragged by a motor are arranged in the starting, running, stopping and overhauling processes of the power plant to ensure the normal running of main equipment of the unit, and the motors of the station auxiliary machines and running, operating, testing, overhauling, lighting electric equipment and the like of the whole plant belong to station loads. The service power system is a system consisting of a high-voltage and low-voltage power station transformer, a shutdown/overhaul transformer, a power supply network and a service load of the unit, and comprises a power supply source, the service load, a service bus, a device for controlling the connection or disconnection of a circuit and the like which are all or partially combined. The power frequency station electric system is a power frequency power supply that a power supply of the station electric system leads an outlet of a main steam turbine generator unit or is fed back by a power grid system and the like, the station electric system in China operates under the working condition of power frequency 50Hz, and the station electric systems in other countries, such as the United states, Canada, Japanese Guangxi area and the like, operate under the working condition of power frequency 60 Hz.

Preferably, in the 2 nd novel multi-port electric energy conversion and switching system, the No. 61 connection end of the electric energy converter is further electrically connected with the No. 13 service bus, and the electrical connection relationship can be in two states of on and off.

Preferably, the two novel multiport electric energy conversion and switching systems further include at least one motor of No. 251 auxiliary machine for factory use, and/or at least one motor of No. 451 auxiliary machine for factory use, the motor of No. 251 auxiliary machine for factory use is electrically connected with No. 22 bus for factory use, and/or the motor of No. 451 auxiliary machine for factory use is electrically connected with No. 24 bus for factory use, and the electrical connection relationship can be in two states of on and off.

The magnitude of the delivered power of the power converter can be autonomously controlled. Under various working conditions, the electric energy converter can set different modes and parameters as conditions for adjusting the target value of the transmission power and control the size of the transmission power. The electric energy flowing direction between any two connecting ends of the electric energy converter can be unidirectional or bidirectional.

When the electric energy flow direction between certain two link ends of electric energy converter is two-way flow, through changing the flow direction of electric energy between these two link ends of electric energy converter, can realize the two-way flow of electric energy between different mill buses, if: electric energy flows into the No. 61 connecting end of the electric energy converter from the No. 11 service bus, and flows out to the No. 22 service bus and the No. 24 service bus from the No. 62 connecting end and the No. 64 connecting end of the electric energy converter respectively; electric energy flows into the No. 62 connecting end and the No. 64 connecting end of the electric energy converter from the No. 22 factory bus and the No. 24 factory bus respectively, and flows out to the No. 11 factory bus from the No. 61 connecting end of the electric energy converter; electric energy flows into the No. 62 connecting end of the electric energy converter from the No. 22 factory bus, and flows out to the No. 11 factory bus and the No. 24 factory bus from the No. 61 connecting end and the No. 64 connecting end of the electric energy converter respectively; electric energy flows into the No. 61 connecting end and the No. 64 connecting end of the electric energy converter from the No. 11 factory bus and the No. 24 factory bus respectively, and flows out to the No. 22 factory bus from the No. 62 connecting end of the electric energy converter; electric energy flows into the No. 64 connecting end of the electric energy converter from the No. 24 factory bus, and flows out to the No. 11 factory bus and the No. 22 factory bus from the No. 61 connecting end and the No. 62 connecting end of the electric energy converter respectively; electric energy flows into the No. 61 connecting end and the No. 62 connecting end of the electric energy converter from the No. 11 factory bus and the No. 22 factory bus respectively, and flows out to the No. 24 factory bus from the No. 64 connecting end of the electric energy converter; and the like.

When the electric energy flowing direction between certain two connecting ends of the electric energy converter is in one-way flowing, the electric energy flowing direction between the two connecting ends is unchanged on the premise of not depending on the adjustment of an external operation wiring mode.

Preferably, the 2 nd novel multiport electric energy conversion and switching system further includes a 741 transformer or an 743 transformer, the variable frequency generator is electrically connected to the 11 th service bus through the 741 transformer, or the variable frequency generator is electrically connected to the 13 th service bus through the 743 transformer, and the electrical connection relationship can be in two states of on and off.

Preferably, the 2 nd novel multi-port power conversion and switching system further includes a 711 transformer, a 713 transformer, or a 71113 # three-winding transformer in addition to the 741 transformer or the 743 transformer. The No. 61 connecting end of the electric energy converter is electrically connected with the No. 11 station bus through the No. 711 transformer, or the No. 61 connecting end of the electric energy converter is electrically connected with the No. 13 station bus through the No. 713 transformer, or three windings of the No. 71113 three-winding transformer are respectively electrically connected with the No. 11 station bus, the No. 13 station bus and the No. 61 connecting end of the electric energy converter, and the electric connection relationship can be in two states of conduction and disconnection.

Preferably, the above-mentioned novel multiport power converting and switching system of type 2 further includes two transformers No. 711 and No. 722 or two transformers No. 713 and No. 724 in addition to the transformer No. 741 or No. 743. The No. 61 connecting end of the electric energy converter is electrically connected with the No. 11 service bus through the No. 711 transformer, and the No. 62 connecting end of the electric energy converter is electrically connected with the No. 22 service bus through the No. 722 transformer; or the No. 61 connecting end of the electric energy converter is electrically connected with the No. 13 station bus through the No. 713 transformer, and the No. 64 connecting end of the electric energy converter is electrically connected with the No. 24 station bus through the No. 724 transformer; the electrical connection can be in two states, on and off.

Preferably, the two novel multi-port electric energy conversion and switching systems further comprise a No. 722 transformer and/or a No. 724 transformer. The No. 62 connecting end of the electric energy converter is electrically connected with the No. 22 service bus through the No. 722 transformer, and/or the No. 64 connecting end of the electric energy converter is electrically connected with the No. 24 service bus through the No. 724 transformer, and the electric connection relationship can be in a conducting state and a disconnecting state.

A transformer is arranged between different devices, so that the devices with different voltage grades can be electrically connected.

Preferably, the small turbine directly drives the variable frequency generator, or the small turbine further comprises a number 94 rotating speed conversion device, the small turbine drives the variable frequency generator through the number 94 rotating speed conversion device, and the number 94 rotating speed conversion device can change the corresponding relation of the rotating speed between the small turbine and the variable frequency generator.

The frequency conversion is completely different from the deviation of the transient frequency or the fluctuation of the frequency, the frequency is still considered to be power frequency operation when the frequency operates in the range of 49.5 Hz-50.5 Hz, and the frequency conversion is used for meeting the requirements of frequency conversion speed regulation of a motor of a plant auxiliary machine under different working conditions, so that the power supply frequency is changed, the power consumption is reduced, the loss is reduced, the service life of equipment is prolonged, and the frequency can be changed within a large range.

Preferably, the system further comprises a feed water pump, and the small steam turbine drives the variable frequency generator and simultaneously drives the feed water pump.

Preferably, the system further comprises a number 910 rotating speed conversion device, one end of the small steam turbine rotating shaft drives the variable frequency generator, the other end of the small steam turbine rotating shaft drives the water feeding pump through the number 910 rotating speed conversion device, and the number 910 rotating speed conversion device can change the corresponding relation of the rotating speed between the small steam turbine and the water feeding pump. The variable frequency generator and the main steam turbine generator set share one small steam turbine, so that the investment of the small steam turbine can be reduced, and the investment cost of a centralized variable frequency project is obviously reduced.

The number 94 rotation speed conversion device and the number 910 rotation speed conversion device can be a hydraulic coupling, a gear box, a magnetic coupling or a combination of the hydraulic coupling, the gear box and the magnetic coupling.

The 1 st method for performing electric energy conversion by using any one of the two novel multi-port electric energy conversion and switching systems comprises the following steps: the transmission power is adjusted through the electric energy converter, and surplus electric energy from the variable-frequency generator driven by the small steam turbine on the No. 11 plant bus is supplied through the electric energy converter and converted into electric energy required by a motor of a plant auxiliary machine powered by the No. 22 plant bus and/or the No. 24 plant bus. The electric energy conversion method can supply surplus electric energy of the variable-frequency generator to a motor of a plant auxiliary machine supplied with power by a 22 # plant bus and/or a 24 # plant bus and a plant load of a power-frequency plant electric system in a conducting state in electric connection with the 22 # plant bus and/or the 24 # plant bus by only controlling the transmission power of the electric energy converter, so that partial electric energy of the variable-frequency generator set is supplied to the power-frequency plant electric system of the main steam-turbine generator set.

The 'surplus electric energy' can be that the power-steam source pressure characteristic of the small steam turbine is inconsistent with the power-rotating speed characteristic of the motor of the auxiliary plant machine, when the load of the main steam turbine generator set is reduced by a certain power, the air quantity and flow required to be provided by the auxiliary plant machine participating in the centralized frequency conversion are reduced along with the reduction of the air quantity and the flow, the rotating speed is reduced along with the reduction of the air quantity and the flow, and the power of the motor of the auxiliary plant machine is reduced approximately in a cubic relation along with the reduction of the rotating speed on the basis of the characteristic that the power and the rotating speed are changed in a cubic relation; when the load of the main steam turbine generator set is reduced, the pressure of a steam extraction steam source of a main steam turbine used by a small steam turbine is reduced along with the load, the power of the small steam turbine is reduced approximately in a one-time relation along with the pressure reduction of the steam source under the original opening degree of a steam inlet adjusting valve of the small steam turbine, namely the power change of a motor of a plant auxiliary machine participating in centralized frequency conversion is more obvious than that of the small steam turbine, and a power difference exists between the small steam turbine and the small steam turbine; or the design margin of the extraction steam source of the small steam turbine is adopted, and generally, the power corresponding to the pressure of the extraction steam source designed by the small steam turbine is greater than the sum of the powers of the motors of the auxiliary machines participating in the concentrated frequency conversion; the motor of the auxiliary machine for the plant which participates in the centralized frequency conversion is supplied with power by the power frequency plant power system instead due to the requirements of an operation mode or frequency conversion equipment maintenance and the like, so that the output power of the small steam turbine is greater than the sum of the powers of the actually carried loads; in addition, when the circulating water temperature of the small steam turbine is reduced, the corresponding exhaust pressure is reduced, the enthalpy drop of the steam is increased, and the output power is increased, so that the output power of the small steam turbine is larger than the sum of the power of the actually carried loads.

The 2 nd method for performing electric energy conversion by using any one of the two novel multi-port electric energy conversion and switching systems comprises the following steps: the output power of the small steam turbine is increased by adjusting the opening degree of a steam inlet adjusting valve of the small steam turbine, the transmission power is adjusted by the electric energy converter, and surplus electric energy from a variable-frequency generator driven by the small steam turbine on the No. 11 plant bus is used for providing electric energy for a motor of a plant auxiliary machine powered by the No. 22 plant bus and/or the No. 24 plant bus through the electric energy converter. The method for converting the electric energy can reduce or even eliminate throttling loss by controlling the opening of the steam inlet adjusting valve of the small steam turbine and the transmission power of the electric energy converter in a linkage manner, and supplies the increased surplus electric energy to a motor of a plant auxiliary machine powered by a 22 # plant bus and/or a 24 # plant bus and a plant load of a power frequency plant electric system in a conduction state in an electric connection with the 22 # plant bus and/or the 24 # plant bus, so that part of electric energy of the variable frequency generator set is supplied to the power frequency plant electric system of the main steam turbine generator set, on one hand, the efficiency of the variable frequency generator set is improved, on the other hand, the plant power rate directly supplied by the main steam turbine generator set system is reduced, the economic benefit is increased, and the energy-saving effect is achieved.

In the two methods for converting the electric energy, the operating frequencies of the No. 11 service bus, the No. 22 service bus and the No. 24 service bus can be different by adjusting the frequency of the connection end of the electric energy converter (while adjusting the frequency, the voltage can be changed therewith). Bus, 22 # factory bus, 24 # factory bus can operate in different frequency conversion frequency simultaneously for 11 # factory, 22 # factory, like: the running frequency of the No. 11 service bus is 45Hz, the running frequency of the No. 22 service bus is 40Hz, and the running frequency of the No. 24 service bus is 35 Hz; for another example: the running frequency of the No. 11 service bus is 40Hz, the running frequency of the No. 22 service bus is 45Hz, and the running frequency of the No. 24 service bus is 50 Hz; the following steps are repeated: the running frequency of the No. 11 service bus is 46Hz, the running frequency of the No. 22 service bus is 48Hz, and the running frequency of the No. 24 service bus is 43 Hz; and the motor of the auxiliary machine powered by the No. 11 auxiliary bus, the motor of the auxiliary machine powered by the No. 22 auxiliary bus and the motor of the auxiliary machine powered by the No. 24 auxiliary bus can simultaneously run at different variable frequency frequencies, so that the requirements that the motors of different auxiliary machines run at different frequencies at the same time are met.

The 3 rd method for performing electric energy conversion by using any one of the two novel multi-port electric energy conversion and switching systems comprises the following steps: the transmission power is adjusted through the electric energy converter, and the power frequency electric energy of the power frequency plant electric system is supplied through the electric energy converter and converted into the variable frequency electric energy required by the motor of the auxiliary plant auxiliary machine. Such as: the power frequency power station system is electrically connected with the No. 22 station bus, the transmission power is adjusted through the electric energy converter, and the power frequency electric energy from the power frequency power station system on the No. 22 station bus is supplied through the electric energy converter and converted into the frequency conversion electric energy required by the motor of the auxiliary station machine powered by the No. 11 station bus and the motor of the auxiliary station machine powered by the No. 24 station bus; for another example: the power frequency power station system is electrically connected with the No. 24 station bus, the transmission power is adjusted through the electric energy converter, and the power frequency electric energy from the power frequency power station system on the No. 24 station bus is supplied through the electric energy converter and converted into the frequency conversion electric energy required by the motor of the auxiliary station machine powered by the No. 11 station bus and the motor of the auxiliary station machine powered by the No. 22 station bus; and the like. The electric power of the main steam turbine generator set or the power grid system is supplied to the frequency conversion system, so that on one hand, the design allowance of the capacity of the frequency conversion generator can be reduced, and on the other hand, the bottleneck that the steam inlet quantity of the small steam turbine is insufficient can be relieved. When the variable-frequency generator or the small steam turbine needs to quit operation due to maintenance or failure, the motor of the auxiliary machine for the plant can continue to provide electric energy with variable frequency by the power frequency plant system through the electric energy converter.

The utility model provides an utilize the electric energy conversion of above-mentioned two kinds of novel multiport and the method of arbitrary one in the switched systems, can utilize the electric energy conversion of above-mentioned two kinds of novel multiport and arbitrary one in the switched systems to realize the motor start-up of auxiliary engine and/or not switching of cutting off the power supply. The starting and/or switching of the motor of the auxiliary machinery is assisted by adjusting the transmission power of the electric energy converter, adjusting the frequency and/or voltage of at least one end of the electric energy converter and changing the connection and disconnection relation of the electric connection between related equipment in the system (such as the electric connection relation between the No. 61 connecting end of the electric energy converter and the No. 11 service bus, the electric connection relation between the No. 62 connecting end of the electric energy converter and the No. 22 service bus, the electric connection relation between the No. 64 connecting end of the electric energy converter and the No. 24 service bus, the electric connection relation between the motor of the No. 51 auxiliary machinery and the No. 11 service bus, the electric connection relation between the motor of the No. 51 auxiliary machinery and the No. 22 service bus, and the like). The method for assisting the starting and/or switching of the motor of the auxiliary machine for the factory by utilizing any one of the two novel multi-port electric energy conversion and switching systems increases the flexibility of the switching of the motor of the auxiliary machine for the factory, can realize the switching of the motor of the auxiliary machine for the factory under the variable-frequency working condition, and breaks through the bottleneck that the motor of the auxiliary machine for the factory can not be switched under the variable-frequency working condition in the past. The method for starting the motor of the auxiliary machine reduces the influence of impact current generated when the motor of the auxiliary machine is started on a system, and can prolong the service life of the motor of the auxiliary machine.

The 1 st method for assisting the starting and/or switching of the motor of the auxiliary plant machine by utilizing any one of the two novel multiport electric energy conversion and switching systems adjusts the transmission power of the electric energy converter, adjusts the frequency and/or voltage of at least one end of the electric energy converter, changes the connection and disconnection relation of electric connection in the system, directly provides electric energy for the motor of the auxiliary plant machine No. 51 and/or No. 251 from a power frequency plant electric system through a No. 22 plant bus, and provides electric energy for the electric energy converter through a No. 22 plant bus.

The 1 st method for assisting the starting and/or switching of the motor of the auxiliary machine by using any one of the two novel multiport electric energy conversion and switching systems comprises the following specific steps:

firstly, the electric connection relation between the power frequency plant electric system and the No. 22 plant bus is in a conducting state, the electric connection relation between the motor of the No. 51 and/or No. 251 plant auxiliary machine and the No. 11 plant bus is in a disconnecting state or has no electric connection, the electric energy converter is not put into operation, the motor of the No. 51 and/or No. 251 plant auxiliary machine is directly supplied with electric energy by the power frequency plant electric system through the No. 22 plant bus, and the motor of the No. 51 and/or No. 251 plant auxiliary machine can be originally in operation or just started by the power frequency plant electric system;

secondly, putting the electric energy converter into operation, increasing the transmission power of the electric energy converter, and transferring the motors of the No. 51 and/or No. 251 auxiliary plant machines to the electric energy converter to provide electric energy through a No. 22 auxiliary plant bus;

and thirdly, changing the electrical connection relation between the No. 22 auxiliary bus and the power frequency auxiliary power system into a disconnected state.

And 2, by utilizing any one of the two novel multiport electric energy conversion and switching systems to help the motor of the auxiliary plant machine to start and/or switch, the motor of the auxiliary plant machine No. 51 is switched by supplying electric energy from the electric energy converter through the auxiliary plant bus No. 22 and directly supplying electric energy from the variable frequency generator through the auxiliary plant bus No. 11 by adjusting the transmission power of the electric energy converter and adjusting the frequency and/or voltage of at least one end of the electric energy converter and changing the connection and disconnection relation of electric connection in the system.

The 2 nd method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant by utilizing any one of the two novel multi-port electric energy conversion and switching systems comprises the following specific steps:

firstly, the electric connection relation between the motor of the No. 51 auxiliary plant machine and the No. 11 bus is in a disconnection state, the electric connection relation between the No. 22 bus and the power frequency power plant electric system is in a disconnection state, and the motor of the No. 51 auxiliary plant machine is supplied with electric energy through the No. 22 bus by an electric energy converter;

secondly, adjusting the frequency and/or voltage of the No. 22 service bus through an electric energy converter to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel, wherein parameters such as voltage difference, phase difference, frequency difference and the like meet the closing condition of quasi-synchronization and/or check synchronization and the like;

thirdly, changing the electric connection relation between the motor of the auxiliary machine for factory use No. 51 and the bus for factory use No. 11 into a conduction state;

and fourthly, reducing the transmission power of the electric energy converter, or changing the electric connection relation between the motor of the No. 51 auxiliary plant machine and the No. 22 auxiliary plant bus into a disconnection state, or changing the electric connection relation between the electric energy converter and the No. 11 auxiliary plant bus into a disconnection state, or changing the electric connection relation between the electric energy converter and the No. 22 auxiliary plant bus into a disconnection state, so that the motor of the No. 51 auxiliary plant machine is directly supplied with electric energy by the variable frequency generator through the No. 11 auxiliary plant bus.

By independently using the method for assisting the starting and/or switching of the motor of the auxiliary plant machine 1, the motor of the auxiliary plant machine No. 51 and/or No. 251 can be directly supplied with electric energy from the power frequency plant electric system through the power bus No. 22, and can be switched to be supplied with electric energy from the electric energy converter through the power bus No. 22.

By using the method for assisting the starting and/or switching of the motor of the auxiliary plant machine 2, the motor of the auxiliary plant machine 51 can be directly supplied with electric energy through the auxiliary bus 22 by the variable frequency generator and the auxiliary bus 11 by the electric energy converter.

Firstly, the method for assisting the starting and/or switching of the motor of the auxiliary plant machine 1 is used, and then the method for assisting the starting and/or switching of the motor of the auxiliary plant machine 2 is used, so that the motor of the auxiliary plant machine 51 can be directly provided with electric energy from the power frequency power plant system through the power station bus 22, and can be directly provided with electric energy from the variable frequency generator through the power station bus 11.

And 3, starting the motor of the auxiliary machine for the 51 st plant by the electric energy converter through the bus for the 22 st plant and providing electric energy by adjusting the transmission power of the electric energy converter and adjusting the frequency and/or voltage of at least one end of the electric energy converter and changing the connection and disconnection relation of electric connection in the system by utilizing any one of the two novel multi-port electric energy conversion and switching systems, and then switching to directly provide the electric energy by the variable frequency generator through the bus for the 11 st plant.

The 3 rd method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant by utilizing any one of the two novel multi-port electric energy conversion and switching systems comprises the following specific steps:

firstly, the electric connection relation between a motor of the No. 51 auxiliary plant machine and the No. 11 bus is in a disconnection state, the electric connection relation between the No. 22 bus and the power frequency power plant electric system is in a disconnection state, and the electric energy converter is in an operation state;

secondly, setting the initial frequency and the initial voltage of a connecting end of the electric energy converter, which is in a conducting state with the electric connection relation of the No. 22 factory bus and the No. 51 factory auxiliary machine, changing the electric connection relation of the No. 51 factory auxiliary machine and the No. 22 factory bus into a conducting state, and starting the motor of the No. 51 factory auxiliary machine through the No. 22 factory bus by the electric energy converter and providing electric energy;

thirdly, regulating the frequency and/or voltage of the No. 22 service bus through the electric energy converter, and gradually changing the frequency and/or voltage from the initial frequency and the initial voltage to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel;

fourthly, changing the electric connection relation between the motor of the auxiliary machine for factory service No. 51 and the bus for factory service No. 11 into a conduction state;

and fifthly, reducing the transmission power of the electric energy converter, or changing the electric connection relation between the motor of the auxiliary machine 51 and the auxiliary bus 22 into a disconnection state, or changing the electric connection relation between the electric energy converter and the auxiliary bus 11 into a disconnection state, or changing the electric connection relation between the electric energy converter and the auxiliary bus 22 into a disconnection state, so that the motor of the auxiliary machine 51 is directly supplied with electric energy through the auxiliary bus 11 by the variable frequency generator.

In the third step, the frequency and the voltage of the No. 22 plant bus are synchronously adjusted by the power converter, and/or the frequency or the voltage of the No. 22 plant bus is independently adjusted by the power converter, so that the frequency or the voltage gradually changes to meet the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel, and in the process, the electric quantity of the motor of the No. 51 plant auxiliary machine does not exceed the allowable value, such as electric quantities of current, voltage, frequency and the like.

In the third step, the method for adjusting the frequency and/or the voltage of the No. 22 service bus includes the specific steps of:

in the first step, the frequency or voltage of the No. 22 service bus is independently adjusted through the electric energy converter. Such as: the frequency of a No. 22 factory bus is independently adjusted through an electric energy converter; for another example: the voltage of a No. 22 factory bus is independently regulated through an electric energy converter; the following steps are repeated: the voltage of the No. 22 service bus is independently adjusted through the electric energy converter, and then the frequency of the No. 22 service bus is independently adjusted; the method also comprises the following steps: the frequency of the No. 22 service bus is independently adjusted through the electric energy converter, and then the voltage of the No. 22 service bus is independently adjusted; and the like.

And secondly, synchronously adjusting the frequency and the voltage of the No. 22 factory bus through the electric energy converter, so that the frequency and the voltage gradually change to meet the condition that the No. 11 factory bus and the No. 22 factory bus can run in parallel, and the electric quantity of the motor of the No. 51 factory auxiliary machine does not exceed an allowable value in the process.

In the above-mentioned 3 rd method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant, the lowest value of the initial frequency set by the power converter may be the lowest frequency allowed by the power converter, and the lowest value of the initial voltage may be 0V.

In the third step, when the initial frequency and the initial voltage of the connection end, in which the electrical connection relationship between the electrical energy converter and the No. 22 service bus is set, in the on state are both less than the operating frequency and the operating voltage of the No. 11 service bus, the frequency and the voltage of the No. 22 service bus are synchronously adjusted by the electrical energy converter, so that the frequency and the voltage gradually increase to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel. Such as: the power frequency of the plant power system is 50Hz, the corresponding rated voltage is 6kV, when the running frequency and the running voltage of the No. 11 plant bus are respectively 41Hz and 4.9kV, the initial frequency and the initial voltage of the electric energy converter are respectively 16Hz and 1.9kV, the frequency and the voltage of the No. 22 plant bus are synchronously adjusted by the electric energy converter to gradually rise to 22Hz and 2.6kV, and then to 34Hz and 3.9kV until the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel is met.

In the third step, when the initial frequency and the initial voltage of the connection end, in which the electrical connection relationship between the electrical energy converter and the No. 22 service bus is set, in the on state are both less than the operating frequency and the operating voltage of the No. 11 service bus, the voltage of the No. 22 service bus is independently adjusted through the electrical energy converter, and then the frequency and the voltage of the No. 22 service bus are synchronously adjusted through the electrical energy converter, so that the voltage gradually rises to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel. Such as: the power frequency of the plant power system is 60Hz, the corresponding rated voltage is 10kV, when the running frequency and the running voltage of the No. 11 plant bus are respectively 38Hz and 6.3kV, the initial frequency and the initial voltage of the electric energy converter are respectively 21Hz and 0kV, the voltage of the No. 22 plant bus is independently adjusted to be increased to 3.5kV through the electric energy converter, then the frequency and the voltage of the No. 22 plant bus are synchronously adjusted to be increased to 27Hz and 4.45kV through the electric energy converter, and then the frequency and the voltage of the No. 33Hz and 5.45kV are adjusted until the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel is met.

In the third step, when the initial frequency of the connection end, in which the electric energy converter and the No. 22 plant bus are electrically connected, in a conducting state is set to be higher than the operating frequency of the No. 11 plant bus and the initial voltage is lower than the operating voltage of the No. 11 plant bus, the voltage of the No. 22 plant bus is independently adjusted through the electric energy converter, and then the frequency and the voltage of the No. 22 plant bus are synchronously adjusted through the electric energy converter, so that the voltage and the frequency gradually decrease to meet the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel. Such as: the power frequency of the plant power system is 50Hz, the corresponding rated voltage is 10kV, when the running frequency and the running voltage of the No. 11 plant bus are 47Hz and 9.3kV respectively, the initial frequency and the initial voltage of the electric energy converter are set to be 50Hz and 0.5kV respectively, the voltage of the No. 22 plant bus is independently adjusted to be increased to 10kV through the electric energy converter, then the frequency and the voltage of the No. 22 plant bus are synchronously adjusted to be decreased to 49Hz and 9.8kV through the electric energy converter, and then the voltage is increased to 48Hz and 9.55kV until the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel is met.

In the third step, when the initial frequency of the connection end, in which the electric energy converter is electrically connected to the No. 22 service bus, in the on state is set to be equal to the operating frequency of the No. 11 service bus, and the initial voltage is lower than the operating voltage of the No. 11 service bus, the voltage of the No. 22 service bus is independently adjusted by the electric energy converter, so that the voltage gradually rises to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel. Such as: the power frequency of the plant power system is 50Hz, the corresponding rated voltage is 10kV, the running frequency and the running voltage of the No. 11 plant bus are respectively 45Hz and 8.9kV, the initial frequency and the initial voltage of the electric energy converter are respectively set to be 45Hz and 0kV, and the voltage of the No. 22 plant bus is independently regulated by the electric energy converter to rise to meet the condition that the No. 11 plant bus and the No. 22 plant bus can run in parallel.

The above-mentioned 3 rd method for assisting the starting and/or switching of the motor of the auxiliary plant machine can realize that the motor of the auxiliary plant machine No. 51 is started and provided with electric energy by the electric energy converter through the auxiliary bus No. 22, and then the electric energy is directly provided by the variable frequency generator through the auxiliary bus No. 11. By using the method for assisting the starting of the motor of the auxiliary machine in the 3 rd mode, the influence of impact current generated when the motor of the auxiliary machine is started on a system is reduced, and the service life of the motor of the auxiliary machine in the factory can be prolonged.

And 4, utilizing any one of the two novel multiport electric energy conversion and switching systems to help the motor of the auxiliary plant machine to start and/or switch, adjusting the transmission power of the electric energy converter, adjusting the frequency and/or voltage of at least one end of the electric energy converter, and changing the connection and disconnection relation of electric connection in the system, so that the motor of the auxiliary plant machine 51 is directly supplied with electric energy by the variable frequency generator through the auxiliary plant bus 11, and the electric energy converter is directly supplied with electric energy through the auxiliary plant bus 22.

The 4 th method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant by utilizing any one of the two novel multi-port electric energy conversion and switching systems comprises the following specific steps:

firstly, the electric connection relation between the motor of the No. 51 auxiliary plant machine and the No. 22 auxiliary plant bus is in a disconnected state, the electric connection relation between the No. 22 auxiliary plant bus and the power frequency auxiliary plant electric system is in a disconnected state, the motor of the No. 51 auxiliary plant machine is directly provided with electric energy by a variable frequency generator through the No. 11 auxiliary plant bus, and an electric energy converter is in an operating state;

secondly, adjusting the frequency and/or voltage of the No. 22 service bus through an electric energy converter to meet the condition that the No. 11 service bus and the No. 22 service bus can run in parallel;

thirdly, changing the electric connection relation between the motor of the auxiliary machine for factory service No. 51 and the bus for factory service No. 22 into a conduction state;

fourthly, increasing the transmission power of the electric energy converter, and transferring the motor of the auxiliary machine for the No. 51 plant to the electric energy converter to provide electric energy through a bus for the No. 22 plant;

and fifthly, changing the electric connection relation between the motor of the auxiliary machine 51 and the auxiliary bus 11 into a disconnection state, and supplying electric energy to the motor of the auxiliary machine 51 through the auxiliary bus 22 by an electric energy converter.

And 5, by utilizing any one of the two novel multiport electric energy conversion and switching systems to help the motor of the auxiliary plant machine to start and/or switch, the motor of the auxiliary plant machine No. 51 and/or No. 251 is switched to be directly supplied with electric energy by the electric energy converter through the auxiliary plant bus No. 22 by adjusting the transmission power of the electric energy converter, adjusting the frequency and/or voltage of at least one end of the electric energy converter and changing the connection and disconnection relation of electric connection in the system.

The 5 th method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant by utilizing any one of the two novel multi-port electric energy conversion and switching systems comprises the following specific steps:

the first step is as follows: the electric connection relation between the motor of the auxiliary machine for the No. 51 and/or No. 251 plant and the No. 11 plant bus is in a disconnected state or has no electric connection, the electric connection relation between the No. 22 plant bus and the power frequency plant electric system is in a disconnected state, the electric energy converter is in an operating state, and the motor of the auxiliary machine for the No. 51 and/or No. 251 plant is supplied with electric energy by the electric energy converter through the No. 22 plant bus;

the second step is that: the frequency and/or voltage of the No. 22 station bus are/is adjusted through the electric energy converter, so that the condition that the No. 22 station bus and the power frequency station power system can run in parallel is met;

thirdly, changing the electrical connection relation between the No. 22 station service bus and the power frequency station service system into a conduction state;

and fourthly, reducing the transmission power of the electric energy converter, or changing the electric connection relation between the electric energy converter and the No. 11 station bus into a disconnection state, or changing the electric connection relation between the electric energy converter and the No. 22 station bus into a disconnection state, so that the motors of the No. 51 and/or No. 251 station auxiliary machines can directly provide electric energy from the power frequency station system through the No. 22 station bus.

By using the above-mentioned method for assisting the starting and/or switching of the motor of the auxiliary plant machine 4 alone, it can be realized that the motor of the auxiliary plant machine 51 is directly supplied with electric energy by the variable frequency generator through the auxiliary bus 11, and is switched over to be supplied with electric energy by the electric energy converter through the auxiliary bus 22.

By independently using the above-mentioned method for assisting the starting and/or switching of the motor of the auxiliary plant machine of the 5 th type, the motor of the auxiliary plant machine of the 51 st and/or the 251 st type can be switched to be directly supplied with electric energy by the power grid system of the power grid through the bus of the 22 st type through the electric energy converter supplying electric energy through the bus of the power grid bus of the 22 st type.

Firstly, the 4 th method for assisting the starting and/or switching of the motor of the auxiliary plant is used, and then the 5 th method for assisting the starting and/or switching of the motor of the auxiliary plant is used, so that the motor of the auxiliary plant of No. 51 can directly provide electric energy through the variable frequency generator and the No. 11 auxiliary bus, and can directly provide electric energy through the power frequency system and the No. 22 auxiliary bus.

And 6, starting the motor of the auxiliary machine for the 51 st plant by the electric energy converter through the bus for the 11 st plant and providing electric energy by adjusting the transmission power of the electric energy converter and adjusting the frequency and/or voltage of at least one end of the electric energy converter and changing the connection and disconnection relation of electric connection in the system by utilizing any one of the two novel multi-port electric energy conversion and switching systems, and then switching to directly provide electric energy by the variable frequency generator through the bus for the 11 st plant.

The 6 th method for assisting the starting and/or switching of the motor of the auxiliary machine for the plant by utilizing any one of the two novel multi-port electric energy conversion and switching systems comprises the following specific steps:

firstly, the electric connection relation between a power frequency station electric system and a No. 22 station bus is in a conducting state, the electric connection relation between a variable frequency generator and a No. 11 station bus is in a disconnecting state, the electric connection relation between a motor of a No. 51 station auxiliary machine and the No. 22 station bus is in a disconnecting state or has no electric connection, and an electric energy converter is in a running state;

secondly, setting the initial frequency and the initial voltage of a connecting end of the electric energy converter, which is in a conducting state with the electric connection relation between the electric energy converter and the No. 11 factory bus, changing the electric connection relation between the motor of the No. 51 factory auxiliary machine and the No. 11 factory bus into a conducting state, and starting the motor of the No. 51 factory auxiliary machine through the No. 11 factory bus by the electric energy converter and providing electric energy;

thirdly, regulating the frequency and/or voltage of the No. 11 service bus through the electric energy converter, and gradually changing the frequency and/or voltage from the initial frequency and the initial voltage to meet the condition that the No. 11 service bus and the variable frequency generator can run in parallel;

fourthly, changing the electrical connection relation between the variable frequency generator and the No. 11 service bus into a conduction state;

and fifthly, reducing the transmission power of the electric energy converter, or changing the electric connection relation between the electric energy converter and the No. 11 station bus into a disconnection state, or changing the electric connection relation between the electric energy converter and the No. 22 station bus into a disconnection state, or changing the electric connection relation between the power frequency station electric system and the No. 22 station bus into a disconnection state, so that the electric energy is directly provided for the motor of the No. 51 station auxiliary machine through the No. 11 station bus by the variable frequency generator.

The above-mentioned 6 method for assisting the starting and/or switching of the motor of the auxiliary plant machine can realize that the motor of the auxiliary plant machine No. 51 is started and provided with electric energy by the electric energy converter through the auxiliary plant bus No. 11, and then the electric energy is directly provided by the variable frequency generator through the auxiliary plant bus No. 11. By using the method for assisting the starting of the motor of the auxiliary equipment in the 6 th mode, the influence of the impact current generated when the motor of the auxiliary equipment is started on the system is reduced, and the service life of the motor of the auxiliary equipment can be prolonged.

The motor of the auxiliary machine for factory use of No. 52 and/or No. 451 can also start and/or switch the motor of the auxiliary machine for factory use according to the similar operation steps, such as: the power frequency station service system directly provides electric energy through a No. 24 station service bus, and the electric energy converter provides electric energy through the No. 24 station service bus; the electric energy converter provides electric energy through a No. 24 station bus, and the variable frequency generator directly provides electric energy through a No. 13 station bus; the electric energy converter is started and provides electric energy through a No. 24 station bus, and then the variable frequency generator is switched to directly provide the electric energy through a No. 13 station bus; the variable frequency generator directly provides electric energy through a No. 13 station bus, and the electric energy converter provides electric energy through a No. 24 station bus; the electric energy converter provides electric energy through a No. 24 station bus to switch over and directly provides electric energy through a No. 24 station bus by a power frequency station electric system; the electric energy converter is started and provides electric energy through the No. 13 station bus, and then the variable frequency generator is switched to directly provide the electric energy through the No. 13 station bus; and the like.

According to the method for assisting the starting and/or switching of the motors of the auxiliary machinery, the motors of a plurality of auxiliary machinery can be started and/or switched simultaneously. Such as: the motors of the 51 # auxiliary machines are started and/or switched at the same time; the motors of the auxiliary machines for the No. 52 factory are started and/or switched at the same time; the motors of the 51 # auxiliary factory machines and the motors of the 52 # auxiliary factory machines are started and/or switched simultaneously; and the like.

The utility model provides a pair of novel electric energy conversion and switched systems of multiport, the flexibility that the motor of auxiliary machine was switched has been increased to arbitrary one kind in above-mentioned 6 kinds of electric energy conversion and the switched systems who utilize above-mentioned three kinds of novel multiport help mill auxiliary machine's motor start-up and/or switching, wherein the switching of the motor of auxiliary machine is used to 1 st, 2 nd, 3 rd, 4 th, 6 th method can realize mill under the frequency conversion operating mode. The operating frequency and/or voltage of the No. 22 (No. 24) factory bus are/is adjusted to meet the condition that the No. 11 (No. 13) factory bus and the No. 22 (No. 24) factory bus can run in parallel, the switching of the motor of the factory auxiliary machine under the variable-frequency working condition is realized, and the bottleneck that the motor of the conventional factory auxiliary machine cannot be switched under the variable-frequency working condition is broken through.

The utility model provides a pair of be applied to electric energy conversion and switching system of novel multiport of thermal power factory compares with prior art, mainly has following advantage:

1. the steam inlet regulating valve of the small steam turbine is opened as large as possible or even in a fully open state, throttling loss generated in the prior art is reduced or even eliminated, output power of the small steam turbine is correspondingly increased, and the increased power can be supplied to a power frequency station power system of the main steam turbine generator set through the electric energy converter, so that the overall efficiency of the system is improved, the station power consumption rate of the main steam turbine generator set system is reduced, economic benefits are increased, and an energy-saving effect is achieved.

2. The electric power of the main steam turbine generator set or the power grid system is supplied to the frequency conversion system, so that on one hand, the design allowance of the capacity of the frequency conversion generator can be reduced, and on the other hand, the bottleneck that the steam inlet quantity of the small steam turbine is insufficient can be relieved. When the variable-frequency generator or the small steam turbine needs to quit operation due to maintenance or failure, the motor of the auxiliary machine for the plant can continue to provide electric energy with variable frequency by the power frequency plant system through the electric energy converter.

3. By adjusting the transmission power through the electric energy converter, the following can be realized: electric energy flows in from any one connecting end, and flows out from the other two connecting ends; electric energy flows in from any two connecting ends, and the other connecting end flows out; the electric energy flows in from any one connecting end, and flows out from any one of the other two connecting ends.

4. By adjusting the frequency of the connecting ends of the electric energy converter, the operating frequencies of the three connecting end sides of the electric energy converter can be different, and the requirement that the motors of the auxiliary plant machines which are respectively supplied with power by each section of the auxiliary plant bus operate at different frequencies at the same moment is met.

5. The system power balance can be maintained by adjusting the transmission power through the electric energy converter.

6. The transmission power is adjusted through the electric energy converter, so that the frequency corresponding to the air quantity and the flow required by the motor of the auxiliary machine, which is powered by the No. 11 (No. 13) industrial bus and runs on the industrial auxiliary machine, corresponding to the load of the main steam turbine generator set can be controlled, and the throttling loss generated by the existing centralized variable-frequency power supply technology is reduced or even eliminated.

7. The utility model provides a switching method of motor of auxiliary engine for factory realizes the switching of motor of auxiliary engine for factory under the frequency conversion operating mode, has increased the flexibility that the motor of auxiliary engine for factory switches, has broken through the bottleneck that the motor of auxiliary engine for factory can not switch under the frequency conversion operating mode in the past, can reduce the motor of auxiliary engine for factory simultaneously and can only operate the time at power frequency factory power consumption system under the operating mode that does not satisfy the switching to reduce energy consumption and factory power consumption rate.

8. The utility model provides a starting method of motor of auxiliary engine for plant, the impact current that produces when having reduced the motor start-up of auxiliary engine for plant to the influence of system still can prolong the electrodynamic life of auxiliary engine for plant.

9. The variable frequency generator and the main steam turbine generator set share one small steam turbine, so that the investment of the small steam turbine can be reduced, and the investment cost of a centralized variable frequency project is obviously reduced.

10. The utility model provides a switching method of motor of auxiliary engine for plant can realize that the motor of auxiliary engine for plant accomplishes the switching under the circumstances of not cutting off the power supply.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings, so as to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 to 4 are schematic diagrams of the embodiments of the present invention:

the labels in the figure are:

11: no. 11 service bus;

13: no. 13 service bus;

22: no. 22 service bus;

24: 24 # service bus;

4: a variable frequency generator;

41: the device is used for connecting or disconnecting the variable frequency generator with a control circuit electrically connected with the No. 11 factory bus;

43: the device is used for connecting or disconnecting the variable frequency generator with a control circuit electrically connected with the No. 13 factory bus;

44: a small steam turbine;

45: an inlet regulating valve of the small steam turbine;

51, 52, 251, 451: a motor of the auxiliary machine for factory use;

511, 512: a device for connecting or disconnecting the motor of the auxiliary machine No. 51 with a control circuit electrically connected with the auxiliary bus;

521, 522: a device for connecting or disconnecting the control circuit electrically connecting the motor of the auxiliary machine for factory No. 52 with the bus for factory;

2512: a device for connecting or disconnecting a control circuit electrically connected with a factory bus of a motor of the No. 251 factory auxiliary machine;

4512: a device for connecting or disconnecting a control circuit electrically connected to a bus for factory use of a motor of the auxiliary machinery for factory use No. 451;

6: an electric energy converter;

61, 62, 64: a connection terminal of the electric energy converter;

611: the No. 61 connecting end of the electric energy converter is connected or disconnected with a control circuit electrically connected with the No. 11 service bus;

613: the No. 61 connecting end of the electric energy converter is connected or disconnected with a control circuit electrically connected with the No. 13 service bus;

622: the No. 62 connecting end of the electric energy converter is connected or disconnected with a control circuit electrically connected with the No. 22 service bus;

624: the No. 62 connecting end of the electric energy converter is connected or disconnected with a control circuit electrically connected with the No. 24 service bus;

743, 713, 724, 711, 722: a transformer;

8: power frequency power station power utilization system.

82: the power frequency station power system is connected or disconnected with a control circuit electrically connected with a No. 22 station bus;

84: the power frequency station power system is connected or disconnected with a control circuit electrically connected with the 24 # station bus;

94, 910: a rotation speed conversion device.

10: water supply pump

Detailed Description

Detailed description of the invention

As shown in FIG. 1, the embodiment of the multi-port power conversion and switching system of the present invention comprises a factory bus 11, a factory bus 22, a factory bus 24, a variable frequency generator 4, a small turbine 44 for driving the variable frequency generator 4 to generate alternating current with variable frequency, a steam inlet adjusting valve 45 for controlling the steam inlet of the small turbine 44, a power frequency factory system 8, a plurality of motors 51 of the factory auxiliary machines, and a plurality of motors 52 of the factory auxiliary machines 52, and the frequency and/or voltage of at least one connection terminal can be adjusted and the flow of electrical energy between service buses of different frequencies can be controlled, or the electric energy converter 6 can control the electric energy to flow between the service buses with the same frequency and different frequencies, and the electric energy converter 6 comprises a No. 61 connecting end 61, a No. 62 connecting end 62, a No. 64 connecting end 64 and the like. The connection 61 of the electric energy converter 6 is electrically connected with the factory bus 11 No. 11 through the device 611 for connection or disconnection of the control circuit No. 611, the connection 62 of the electric energy converter 6 is electrically connected with the factory bus 22 No. 22 through the device 622 for connection or disconnection of the control circuit No. 622, the connection 64 of the electric energy converter 6 is electrically connected with the factory bus 24 No. 24 through the device 624 for connection or disconnection of the control circuit No. 624, the variable frequency generator 4 is electrically connected with the factory bus 11 No. 11 through the device 41 for connection or disconnection of the control circuit No. 41, the power frequency factory electrical system 8 is electrically connected with the factory bus 22 No. 22 through the device 82 for connection or disconnection of the control circuit No. 82, the power frequency factory electrical system 8 is also electrically connected with the factory bus 24 No. 24 through the device 84 for connection or disconnection of the control circuit No. 84, and the motor 51 of each 51 number of the auxiliary factory electrical equipment is electrically connected with the factory bus 11 through the device 511 for connection or disconnection of the, the motor 51 of each auxiliary device 51 is electrically connected to the auxiliary bus 22 through a device 512 connected or disconnected by a corresponding control circuit 512, the motor 52 of each auxiliary device 52 is electrically connected to the auxiliary bus 11 through a device 521 connected or disconnected by a corresponding control circuit 521, and the motor 52 of each auxiliary device 52 is electrically connected to the auxiliary bus 24 through a device 522 connected or disconnected by a corresponding control circuit 522.

The 1 st method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624 and 522 with the control circuits of No. 41, 82, 611, 624, 511 and 522 connected or disconnected are in the connected state, and the devices 84, 622, 512 and 521 with the control circuits of No. 84 and 622 and 512 and 521 are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

When the load of the main steam turbine generator set is reduced, the power change of the motors 51 and 52 of the multiple auxiliary plant machines 51 and 52 participating in the concentrated variable-frequency operation is smaller, the power change of the steam turbine 44 is more obvious when the steam inlet regulating valve of the steam turbine is in the original opening degree, and the required frequency of the motors 51 and 52 of the multiple auxiliary plant machines 51 and 52 is further reduced. The 622 device for connecting or disconnecting the 622 control circuit is changed into a connection state, and the surplus variable frequency electric energy of the variable frequency generator 4 is converted into power frequency electric energy through the 11 number of plant buses 11 and the electric energy converter 6 by adjusting the transmission power of the electric energy converter 6 and is transmitted to the 22 number of plant buses 22 and the power frequency plant power system 8. Controlling the running frequency of the No. 11 service bus 11 to be the frequency corresponding to the air volume and the flow required to be provided by the motor 51 of the multiple No. 51 service auxiliary machines powered by the No. 11 service bus 11 corresponding to the load of the main steam turbine generator set; the operation frequency of the 24 # factory bus 24 is controlled to be the frequency corresponding to the air volume and the flow required by the load of the main steam turbine generator set corresponding to the motors 52 of the 52 # factory auxiliary machines supplied with power by the 24 # factory bus 24, the 62 side of the 62 # connecting end of the electric energy converter 6 operates at the power frequency, and the 64 side of the 64 # connecting end operates at the variable frequency. On the one hand, the small steam turbine 44 and the variable frequency generator 4 work in a high-efficiency area, the overall system efficiency is improved, on the other hand, part of electric energy of the variable frequency generator 4 is supplied to the power frequency station power utilization system 8 of the main steam turbine generator unit, the station power utilization rate of direct supply of the main steam turbine generator unit is reduced, the economic benefit is increased, and the energy-saving effect is achieved.

The 2 nd method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624 and 522 with the control circuits of No. 41, 82, 611, 624, 511 and 522 connected or disconnected are in the connected state, and the devices 84, 622, 512 and 521 with the control circuits of No. 84 and 622 and 512 and 521 are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

When the steam inlet regulating valve 45 is in the throttling state, the output power of the small steam turbine 44 is increased by regulating the opening degree of the steam inlet regulating valve 45 of the small steam turbine 44, the throttling loss is reduced or even eliminated, the device 622 for connecting or disconnecting the No. 622 control circuit is changed into the connecting state, the transmission power of the electric energy converter 6 is regulated, and the increased variable frequency electric energy is converted into power frequency electric energy through the electric energy converter 6 and is transmitted to the No. 22 power station bus 22 and the power frequency station power system 8. The operation frequency of the No. 11 plant bus 11 is maintained at the air volume and the frequency corresponding to the flow rate required to be supplied by the motors 51 of the multiple No. 51 plant auxiliary machines supplied with power from the No. 11 plant bus 11 in correspondence with the main steam turbine generator set load, and the operation frequency of the No. 24 plant bus 24 is maintained at the air volume and the frequency corresponding to the flow rate required to be supplied by the motors 52 of the multiple No. 52 plant auxiliary machines supplied with power from the No. 24 plant bus 24 in correspondence with the main steam turbine generator set load, and the No. 62 connection end 62 side of the electric energy converter 6 is operated at the line frequency, and the No. 64 connection end 64 side is operated at the variable. On the one hand, the throttling loss is reduced or even eliminated, the transmission power of the small steam turbine 44 is correspondingly increased, the small steam turbine 44 and the variable frequency generator 4 work in a high-efficiency area, the overall efficiency of the system is improved, on the other hand, part of electric energy of the variable frequency generator 4 is supplied to the power frequency station power utilization system 8 of the main steam turbine generator unit, the station power utilization rate of direct supply of the main steam turbine generator unit is reduced, the economic benefit is increased, and the energy-saving effect is achieved.

The 3 rd method for converting the electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624 and 522 with the control circuits of No. 41, 82, 611, 624, 511 and 522 connected or disconnected are in the connected state, and the devices 84, 622, 512 and 521 with the control circuits of No. 84 and 622 and 512 and 521 are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

The device 622 for connecting or disconnecting the No. 622 control circuit is changed into a connection state, and power frequency electric energy from the power frequency plant electric system 8 is converted into variable frequency electric energy from the No. 22 plant bus 22 through the electric energy converter 6 and is conveyed to the No. 11 plant bus 11 and the No. 24 plant bus 24 by adjusting the conveying power of the electric energy converter 6. The operation frequency of the No. 11 plant bus 11 is controlled to the frequency corresponding to the air volume and flow rate required to be provided by the motors 51 of the multiple No. 51 plant auxiliary machines supplied with power by the No. 11 plant bus 11 corresponding to the main steam turbine generator set load, the operation frequency of the No. 24 plant bus 24 is controlled to the frequency corresponding to the air volume and flow rate required to be provided by the motors 52 of the multiple No. 52 plant auxiliary machines supplied with power by the No. 24 plant bus 24 corresponding to the main steam turbine generator set load, the No. 62 connecting end side of the electric energy converter 6 operates at the power frequency, and the No. 64 connecting end side operates at the variable frequency. The electric power of the power frequency plant power system 8 of the main steam turbine generator set is supplied to the motors 51 and 52 of the plurality of No. 51 and No. 52 plant auxiliary machines, so that on one hand, the design allowance of the capacity of the variable frequency generator 4 can be reduced, the investment cost is reduced, and on the other hand, the bottleneck of insufficient steam intake of the small steam turbine 44 can be relieved. When the variable-frequency generator 4 or the small turbine 44 needs to quit operation due to maintenance or failure, the motors 51 and 52 of the multiple No. 51 and No. 52 auxiliary plant machines can continue to provide electric energy with variable frequency from the power system 8 of the industrial power plant through the electric energy converter 6.

By adjusting the transmission power of the electric energy converter 6 and changing the connection and disconnection relationship of the electric connection in the system, the electric energy can also flow into the electric energy converter 6 from the No. 64 connection end 64 of the electric energy converter 6 and flow out from the No. 61 connection end 61 and the No. 62 connection end 62 of the electric energy converter 6; the electric energy flows into the electric energy converter 6 from the No. 61 connecting end 61 and the No. 62 connecting end 62 of the electric energy converter 6 and flows out from the No. 64 connecting end 64 of the electric energy converter 6; the electric energy flows into the electric energy converter 6 from the No. 64 connecting end 64 and the No. 62 connecting end 62 of the electric energy converter 6 and flows out from the No. 61 connecting end 61 of the electric energy converter 6; the electric energy flows into the electric energy converter 6 from the No. 61 connecting end 61 and the No. 64 connecting end 64 of the electric energy converter 6 and flows out from the No. 62 connecting end 62 of the electric energy converter 6; and the like.

The method for assisting the starting and/or switching of the motor of the auxiliary machine for the factory with the system comprises the following steps: when the devices 84, 611, 622, 624 with the control circuits of No. 84, 611, 622, 624 connected or disconnected are in the disconnected state, the devices 41, 82 with the control circuits of No. 41, 82 connected or disconnected are in the connected state, the devices 511, 512 with the control circuits of No. 511, 512 connected or disconnected corresponding to the motor 51 of the auxiliary machine for No. 51 to be started are in the disconnected state, the device 522 with the control circuits of No. 522 corresponding to the motors 52 of the auxiliary machines for No. 52 connected or disconnected is in the disconnected state, and the device 521 with the control circuits of No. 521 connected or disconnected is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for No. 51 to be started and the bus 11 for No. 11 is in a disconnected state, the electric energy converter 6 is not put into operation, the power system 8 for industrial power plant operates, the variable frequency generator 4 provides electric energy for the bus 11 for No. 11, the motors 52 of the auxiliary machines for No. 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is performed on the bus 11 for No. 11.

The device 512 for connecting or disconnecting the 512 control circuit corresponding to the motor 51 of the 51 # auxiliary factory machine to be started is changed into a connection state, the motor 51 of the 51 # auxiliary factory machine is directly started on the 22 # auxiliary factory bus 22 by the industrial frequency industrial power system 8, and the industrial frequency industrial power system 8 provides electric energy through the 22 # auxiliary factory bus 22;

the devices 611 and 622 with the control circuits No. 611 and No. 622 connected or disconnected are changed into a connected state, the electric energy converter 6 is put into operation, the transmission power of the electric energy converter 6 is increased, and the motor 51 of the auxiliary machine No. 51 which is just started is transferred to the electric energy converter 6 to provide electric energy through the bus 22 for No. 22;

the device 82 whose control circuit No. 82 is connected or disconnected is changed to the disconnected state.

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the devices 82, 84, 624 connected or disconnected by the control circuits No. 82, 84, 41 are in a disconnected state, the devices 41, 611, 622 connected or disconnected by the control circuits No. 41, 611, 622 are in a connected state, the device 511 connected or disconnected by the control circuit No. 511 corresponding to the motor 51 of the auxiliary machine for factory No. 51 to be switched is in a disconnected state, the device 512 connected or disconnected by the control circuit No. 512 is in a connected state, the device 522 connected or disconnected by the control circuit No. 522 corresponding to the motors 52 of the auxiliary machines for factory No. 52 is in a disconnected state, and the device 521 connected or disconnected by the control circuit No. 521 is in a connected state. The electric connection relation between the motor 51 of the to-be-switched No. 51 auxiliary plant machine and the No. 11 auxiliary plant bus 11 is in a disconnected state, the electric energy converter 6 provides electric energy through the No. 22 auxiliary plant bus 22, the power frequency auxiliary plant electric system 8 operates, the variable frequency generator 4 provides electric energy for the No. 11 auxiliary plant bus 11, the variable frequency generator 4 provides electric energy for the motors 52 of the multiple No. 52 auxiliary plant machines, and the variable frequency operation is performed on the No. 11 auxiliary plant bus 11;

the frequency and/or the voltage of the No. 22 factory bus 22 are/is adjusted through the electric energy converter 6 so as to meet the condition that the No. 11 factory bus 11 and the No. 22 factory bus 22 can run in parallel;

a device 511 for connecting or disconnecting the 511 control circuit corresponding to the motor 51 of the switched 51 auxiliary equipment is changed to a connected state;

the transmission power of the electric energy converter 6 is reduced, and the switched motor 51 of the No. 51 auxiliary machinery is directly supplied with electric energy by the variable frequency generator 4 through the No. 11 bus 11.

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the devices 82, 84, 624 with the control circuits connected or disconnected No. 82, 84, 622 are in the disconnected state, the devices 41, 611, 622 with the control circuits connected or disconnected No. 41, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the No. 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in a running state, the power frequency system 8 runs, the variable frequency generator 4 provides electric energy for the bus 11 for the factory service number 11, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 11 for the factory service number 11;

setting an initial frequency and an initial voltage of a No. 62 connecting end 62 of the electric energy converter 6, wherein the initial frequency and the initial voltage are both lower than the running frequency and the running voltage of a No. 11 plant bus 11, changing a device 512 for connecting or disconnecting a No. 512 control circuit corresponding to a motor 51 of a No. 51 plant auxiliary machine to be started into a connection state, starting the motor 51 of the No. 51 plant auxiliary machine on the No. 22 plant bus 22 by the electric energy converter 6, and providing electric energy by the electric energy converter 6 through the No. 22 plant bus 22;

the frequency and the voltage of the No. 22 factory bus are synchronously adjusted through the electric energy converter 6, so that the frequency and the voltage gradually rise to meet the condition that the No. 11 factory bus 11 and the No. 22 factory bus 22 can run in parallel, and the electric quantity of the motor 51 of the No. 51 factory auxiliary machine which is just started in the process does not exceed an allowable value;

a device 511 for connecting or disconnecting the 511 control circuit corresponding to the motor 51 of the just started 51 auxiliary equipment for factory use is changed into a connection state;

the transmission power of the electric energy converter 6 is reduced, the motor 51 of the just started auxiliary machine for the No. 51 factory is switched under the variable-frequency working condition, and the variable-frequency generator 4 directly provides electric energy through the bus 11 for the No. 11 factory.

A 4 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 84, 624 with the control circuits connected or disconnected No. 82, 84, 622 are in the disconnected state, the devices 41, 611, 622 with the control circuits connected or disconnected No. 41, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the No. 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in a running state, the power frequency system 8 runs, the variable frequency generator 4 provides electric energy for the bus 11 for the factory service number 11, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 11 for the factory service number 11;

the voltage of the No. 22 auxiliary bus is independently adjusted through the electric energy converter 6, the voltage gradually rises from the initial voltage, and the electric quantity of the motor 51 of the No. 51 auxiliary machine which is just started in the process does not exceed the allowable value;

then, the frequency and the voltage of the No. 22 factory bus 22 are synchronously adjusted by the electric energy converter 6, so that the frequency and the voltage gradually rise to meet the condition that the No. 11 factory bus 11 and the No. 22 factory bus 22 can run in parallel, and the electric quantity of the motor 51 of the No. 51 factory auxiliary machine which is just started in the process does not exceed an allowable value;

the device 512 for controlling connection or disconnection of the 512 control circuit corresponding to the motor 51 of the just started auxiliary machine for the factory service number 51 is changed into a disconnected state, switching of the motor 51 of the just started auxiliary machine for the factory service number 51 under the variable-frequency working condition is achieved, and the variable-frequency generator 4 directly provides electric energy through the bus 11 for the factory service number 11.

A 5 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 84, 624 with the control circuits connected or disconnected No. 82, 84, 622 are in the disconnected state, the devices 41, 611, 622 with the control circuits connected or disconnected No. 41, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the No. 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in a running state, the power frequency system 8 runs, the variable frequency generator 4 provides electric energy for the bus 11 for the factory service number 11, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 11 for the factory service number 11;

setting an initial frequency and an initial voltage of a No. 62 connecting end 62 of the electric energy converter 6, wherein the initial frequency is higher than the operating frequency of a No. 11 factory bus 11, the initial voltage is lower than the operating voltage of the No. 11 factory bus 11, changing a device 512 for connecting or disconnecting a No. 512 control circuit corresponding to a motor 51 of a No. 51 factory auxiliary machine to be started into a connection state, starting the motor 51 of the No. 51 factory auxiliary machine on the No. 22 factory bus 22 by the electric energy converter 6, and providing electric energy by the electric energy converter 6 through the No. 22 factory bus 22;

then, the frequency and the voltage of the No. 22 factory bus 22 are synchronously adjusted by the electric energy converter 6, so that the frequency and the voltage gradually decrease to meet the condition that the No. 11 factory bus 11 and the No. 22 factory bus 22 can run in parallel, and the electric quantity of the motor 51 of the No. 51 factory auxiliary machine which is just started in the process does not exceed an allowable value;

a device 511 for connecting or disconnecting a No. 511 control circuit corresponding to the No. 51 motor of the No. 51 auxiliary machine which is just started is changed into a connection state;

the device 622 for connecting or disconnecting the No. 622 control circuit is changed into a disconnected state, the motor 51 of the No. 51 auxiliary machine which is just started is switched under the variable-frequency working condition, and the variable-frequency generator 4 directly provides electric energy through the No. 11 auxiliary bus 11.

setting an initial frequency and an initial voltage of a No. 62 connection end 62 of the electric energy converter 6, wherein the initial frequency is equal to the running frequency of a No. 11 plant bus 11, the initial voltage is lower than the running voltage of the No. 11 plant bus 11, changing a device 512 for connecting or disconnecting a No. 512 control circuit corresponding to a motor 51 of a No. 51 plant auxiliary machine to be started into a connection state, starting the motor 51 of the No. 51 plant auxiliary machine by the electric energy converter 6 on a No. 22 plant bus 22, and providing electric energy by the electric energy converter 6 through the No. 22 plant bus 22;

the voltage of the No. 22 factory bus is independently adjusted through the electric energy converter 6, the initial voltage gradually rises to meet the condition that the No. 11 factory bus 11 and the No. 22 factory bus 22 can run in parallel, and the electric quantity of the motor 51 of the No. 51 factory auxiliary machine which is just started in the process does not exceed the allowable value;

A 7 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 84, 624 with the control circuits connected or disconnected No. 82, 84, 622 are in the disconnected state, the devices 41, 611, 622 with the control circuits connected or disconnected No. 41, 611, 622 are in the connected state, the device 512 with the control circuit 512 connected or disconnected corresponding to the motor 51 of the plurality of No. 51 auxiliary machines is in the disconnected state, the device 511 with the control circuit 511 connected or disconnected corresponding to the motor 51 of the plurality of No. 51 auxiliary machines is in the connected state, the device 522 with the control circuit 522 connected or disconnected corresponding to the motor 52 of the plurality of No. 52 auxiliary machines is in the disconnected state, and the device 521 with the control circuit 521 connected or disconnected corresponding to the motor 52 of the plurality of No. 52 auxiliary machines is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for No. 51 and the auxiliary bus 22 for No. 22 is in a disconnection state, the electric connection relation between the auxiliary bus 22 for No. 22 and the power frequency power station electric system 8 is in a disconnection state, the motor 51 of the auxiliary machine for No. 51 is supplied with electric energy by the variable frequency generator 4 through the auxiliary bus 11 for No. 11, and the motor 52 of the auxiliary machine for No. 52 is supplied with electric energy by the variable frequency generator 4 through the auxiliary bus 11 for No. 11;

a device 512 for connecting or disconnecting the 512 control circuit corresponding to the motor 51 of the 51 # auxiliary machine to be switched is changed into a conducting state;

increasing the transmission power of the electric energy converter 6, and transferring the motor 51 of the switched No. 51 auxiliary equipment to the electric energy converter 6 to provide electric energy through the No. 22 auxiliary bus 22;

the device 511 for connecting or disconnecting the 511 control circuit corresponding to the motor 51 of the switched 51 auxiliary equipment is changed to the disconnected state, and the motor 51 of the 51 auxiliary equipment is supplied with electric energy by the electric energy converter 6 through the 22 auxiliary bus 22.

A method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the device 82, 84, 624 with the control circuit connection or disconnection No. 82, 84, 622 is in the disconnection state, the device 41, 611, 622 with the control circuit connection or disconnection No. 41, 611, 622 is in the connection state, the device 511 with the control circuit connection or disconnection No. 511 corresponding to the motor 51 of the auxiliary machine 51 for factory use is in the disconnection state, the device 512 with the control circuit connection or disconnection No. 512 is in the connection state, the device 522 with the control circuit connection or disconnection No. 522 corresponding to the motor 52 of the auxiliary machine for factory use is in the disconnection state, and the device 521 with the control circuit connection or disconnection No. 521 is in the connection state. The electric connection relation between the motor 51 of the No. 51 auxiliary plant machine and the No. 11 auxiliary plant bus 11 is in a disconnection state, the electric connection relation between the No. 22 auxiliary plant bus 22 and the industrial power plant electric system 8 is in a disconnection state, the motor 51 of the No. 51 auxiliary plant machine is supplied with electric energy through the No. 22 auxiliary plant bus 22 by the electric energy converter 6, and the motor 52 of the No. 52 auxiliary plant machine is supplied with electric energy through the No. 11 auxiliary plant bus 11 by the variable frequency generator 4;

the frequency and/or voltage of the No. 22 station bus 22 is adjusted through the electric energy converter 6 so as to meet the condition that the No. 22 station bus 22 and the industrial frequency station power system 8 can run in parallel;

changing the device 82 to the on state, which connects or disconnects the control circuit # 82;

the transmission power of the electric energy converter 6 is reduced, and the electric energy is directly provided for the motor 51 of the No. 51 auxiliary plant machine from the power system 8 of the power plant through the No. 22 bus 22 of the power plant.

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the devices 41, 84, 624 with the control circuits of No. 41, 84, and 624 connected or disconnected are in the disconnected state, the devices 611, 622, 82 with the control circuits of No. 611, 622, and 82 connected or disconnected are in the connected state, the devices 511, 512 with the control circuits of No. 511, 512 connected or disconnected corresponding to the motor 51 of No. 51 auxiliary machinery to be started are in the disconnected state, the device 521 with the control circuits of No. 521 corresponding to the motor 52 of No. 52 auxiliary machinery is in the disconnected state, and the device 522 with the control circuits of No. 522 connected or disconnected corresponding to the motor 522 is in the disconnected state. The electric connection relation between the motor 51 of the auxiliary machine for the plant No. 51 to be started and the plant No. 11 bus 11 is in a disconnected state, the electric connection relation between the motor and the plant No. 22 bus 22 is in a disconnected state, the electric energy converter 6 is in an operating state, and the power frequency plant electric system 8 operates;

setting the initial frequency and the initial voltage of a No. 61 connecting end 61 of the electric energy converter 6, and changing a device 511 for connecting or disconnecting a No. 511 control circuit corresponding to a No. 51 auxiliary machine motor 51 to be started into a connection state, wherein the motor 51 of the No. 51 auxiliary machine is started by the electric energy converter 6 on a No. 11 auxiliary bus 11 and is provided with electric energy by the electric energy converter 6 through the No. 11 auxiliary bus 11;

the frequency and/or the voltage of the No. 11 factory bus 11 are/is adjusted through the electric energy converter 6, so that the frequency and/or the voltage gradually change to meet the condition that the No. 11 factory bus 11 and the variable-frequency generator 4 can run in parallel, and the electric quantity of the motor 51 of the No. 51 factory auxiliary machine which is just started in the process does not exceed an allowable value;

changing the device 41 whose control circuit No. 41 is connected or disconnected to a connected state;

Similarly, the system can also help the motor 52 of the auxiliary machine for the No. 52 factory to start and/or switch; the motors 51 of the multiple No. 51 auxiliary machines are assisted to be started and/or switched simultaneously; the motors 52 of the plurality of No. 52 auxiliary machines for factory use are assisted to be started and/or switched simultaneously; the motors 51 and 52 of the auxiliary machines for the factory No. 51 and No. 52 are assisted to be started and/or switched at the same time; and the like.

The 9 methods for assisting the starting and/or switching of the motor of the auxiliary machine by using the system increase the flexibility of the switching of the motor of the auxiliary machine, wherein the first 7 methods and the 9 th method can realize the switching of the motor of the auxiliary machine under the variable-frequency working condition, and break through the bottleneck that the motor of the auxiliary machine cannot be switched under the variable-frequency working condition.

The above-mentioned 3 rd, 4 th, 5 th, 6 th and 9 th methods for assisting the starting and/or switching of the motor of the auxiliary equipment by using the system, the starting method of the motor of the auxiliary equipment reduces the influence of the inrush current generated when the motor of the auxiliary equipment is started on the system, and can also prolong the service life of the motor of the auxiliary equipment.

Detailed description of the invention

As shown in FIG. 2, the present invention relates to a specific embodiment of a multi-port electrical energy conversion and switching system, which comprises a factory bus 11 No. 11, a factory bus 13 No. 13, a factory bus 22 No. 22, a factory bus 24 No. 24, a variable frequency generator 4, a small steam turbine 44 for driving the variable frequency generator 4 to generate AC power with variable frequency, a steam inlet adjusting valve 45 for controlling the steam inlet amount of the small steam turbine 44, a factory power system 8, a plurality of motors 51 of factory auxiliary machines, a plurality of motors 52 of 52 factory auxiliary machines, and an electrical energy converter 6 capable of adjusting the frequency and/or voltage of at least one connecting end and controlling the electrical energy to flow between the factory buses with different frequencies, or the electrical energy converter 6 capable of controlling the electrical energy to flow between the factory buses with different frequencies and the same frequency, wherein the electrical energy converter 6 comprises a connecting end 61, a connecting end 61, No. 62 link 62 and No. 64 link 64, etc. The No. 61 connecting end 61 of the electric energy converter 6 is electrically connected with the No. 11 station bus 11 through a device 611 for controlling circuit connection or disconnection, the No. 62 connecting end 62 of the electric energy converter 6 is electrically connected with the No. 22 station bus 22 through a device 622 for controlling circuit connection or disconnection, the No. 64 connecting end 64 of the electric energy converter 6 is also electrically connected with the No. 24 station bus 24 through a device 624 for controlling circuit connection or disconnection, the variable frequency generator 4 is electrically connected with the No. 11 station bus 11 through a device 41 for controlling circuit connection or disconnection, the variable frequency generator 4 is also electrically connected with the No. 13 station bus 13 through a device 43 for controlling circuit connection or disconnection, the power frequency station electric system 8 is electrically connected with the No. 22 station bus 22 through a device 82 for controlling circuit connection or disconnection, and the power frequency station electric system 8 is also electrically connected with the No. 24 station bus 24 through a device 84 for controlling circuit connection or disconnection, the motor 51 of each auxiliary device 51 is electrically connected to the auxiliary bus 11 No. 11 through a device 511 to which the corresponding control circuit 511 is connected or disconnected, the motor 51 of each auxiliary device 51 is electrically connected to the auxiliary bus 22 No. 22 through a device 512 to which the corresponding control circuit 512 is connected or disconnected, the motor 52 of each auxiliary device 52 is electrically connected to the auxiliary bus 13 No. 13 through a device 521 to which the corresponding control circuit 521 is connected or disconnected, and the motor 52 of each auxiliary device 52 is electrically connected to the auxiliary bus 24 No. 24 through a device 522 to which the corresponding control circuit 522 is connected or disconnected.

The 1 st method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of No. 41, 82, 611, 624 and multiple numbers 511 and 522 connected or disconnected are in the connected state, and the devices 43, 84, 622, 512 and 521 with the control circuits of No. 43, 84, 622, 512 and 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

The 2 nd method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of No. 41, 82, 611, 624 and multiple numbers 511 and 522 connected or disconnected are in the connected state, and the devices 43, 84, 622, 512 and 521 with the control circuits of No. 43, 84, 622, 512 and 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

The 3 rd method for converting the electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of No. 41, 82, 611, 624 and multiple numbers 511 and 522 connected or disconnected are in the connected state, and the devices 43, 84, 622, 512 and 521 with the control circuits of No. 43, 84, 622, 512 and 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

The method for assisting the starting and/or switching of the motor of the auxiliary machine for the factory with the system comprises the following steps: when the devices 611, 622, 624, 84 with the control circuits connected or disconnected are in the disconnected state, the devices 41, 43, 82 with the control circuits connected or disconnected 41, 43, 82 with 41, 43, 82 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected 511, 512 corresponding to the motor 51 of the auxiliary machine 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines 52 of 52 numbers is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnected state, the electric energy converter 6 is not put into operation, the power system 8 for the industrial power plant operates, the variable frequency generator 4 provides electric energy for the bus 13 for the factory service number 13, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is performed on the bus 13 for the factory service number 13.

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the devices 82, 624, 84 with the connection or disconnection control circuits No. 82, 624, 622 are in the disconnection state, the devices 41, 43, 611, 622 with the connection or disconnection control circuits No. 41, 43, 611, 622 are in the connection state, the device 511 with the connection or disconnection control circuit No. 511 corresponding to the motor 51 of the auxiliary machine for 51 to be switched is in the disconnection state, the device 512 with the connection or disconnection control circuit No. 512 corresponding to the motor 51 of the auxiliary machine for 51 to be switched is in the connection state, the device 522 with the connection or disconnection control circuit No. 522 corresponding to the motors 52 of the auxiliary machines for 52 number 52 is in the disconnection state, and the device 521 with the connection or disconnection control circuit No. 521 corresponding to the auxiliary machine for 52 number 521 is in the connection state. The electric connection relation between the motor 51 of the to-be-switched No. 51 auxiliary plant machine and the No. 11 bus 11 is in a disconnected state, the electric energy converter 6 provides electric energy through the No. 22 bus 22, the power frequency power plant electric system 8 operates, the variable frequency generator 4 provides electric energy for the No. 13 bus 13, the variable frequency generator 4 provides electric energy for the motors 52 of the multiple No. 52 auxiliary plant machines, and the variable frequency operation is performed on the No. 13 bus 13;

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the devices 82, 624, 84 with the control circuits connected or disconnected No. 82, 624, 622 are in the disconnected state, the devices 41, 43, 611, 622 with the control circuits connected or disconnected No. 41, 43, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in an operation state, the power frequency system 8 for the factory service runs, the variable frequency generator 4 provides electric energy for the bus 13 for the factory service number 13, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 13 for the factory service number 13;

A 4 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 624, 84 with the control circuits connected or disconnected No. 82, 624, 622 are in the disconnected state, the devices 41, 43, 611, 622 with the control circuits connected or disconnected No. 41, 43, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in an operation state, the power frequency system 8 for the factory service runs, the variable frequency generator 4 provides electric energy for the bus 13 for the factory service number 13, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 13 for the factory service number 13;

A 5 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 624, 84 with the control circuits connected or disconnected No. 82, 624, 622 are in the disconnected state, the devices 41, 43, 611, 622 with the control circuits connected or disconnected No. 41, 43, 611, 622 are in the connected state, the devices 511, 512 with the control circuits connected or disconnected No. 511, 512 corresponding to the motor 51 of the auxiliary machine for 51 to be started are in the disconnected state, the device 522 with the control circuits connected or disconnected corresponding to the motors 52 of the auxiliary machines for 52 is in the disconnected state, and the device 521 with the control circuits connected or disconnected corresponding to the 521 is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the bus 11 for the factory service number 11 is in a disconnection state, the electric energy converter 6 is in an operation state, the power frequency system 8 for the factory service runs, the variable frequency generator 4 provides electric energy for the bus 13 for the factory service number 13, the motors 52 of the auxiliary machines for the factory service number 52 are provided with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the bus 13 for the factory service number 13;

A 7 th method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the devices 82, 624, 84 with the control circuits connected or disconnected No. 82, 624, 622 are in the disconnected state, the devices 41, 43, 611, 622 with the control circuits connected or disconnected No. 41, 43, 611, 622 are in the connected state, the device 512 with the control circuit 512 connected or disconnected corresponding to the motor 51 of the plurality of No. 51 auxiliary machines is in the disconnected state, the device 511 with the control circuit 511 connected or disconnected corresponding to the motor 51 of the plurality of No. 51 auxiliary machines is in the connected state, the device 522 with the control circuit 522 connected or disconnected corresponding to the motor 52 of the plurality of No. 52 auxiliary machines is in the disconnected state, and the device 521 with the control circuit 521 connected or disconnected corresponding to the motor 52 of the plurality of No. 52 auxiliary machines is in the connected state. The electric connection relation between the motor 51 of the auxiliary machine for No. 51 and the auxiliary bus 22 for No. 22 is in a disconnection state, the electric connection relation between the auxiliary bus 22 for No. 22 and the power frequency power station electric system 8 is in a disconnection state, the motor 51 of the auxiliary machine for No. 51 is supplied with electric energy by the variable frequency generator 4 through the auxiliary bus 11 for No. 11, and the motor 52 of the auxiliary machine for No. 52 is supplied with electric energy by the variable frequency generator 4 through the auxiliary bus 13 for No. 13;

A method of using the system to assist in starting and/or switching the motor of the auxiliary machinery for the plant: when the device 82, 624, 84 with the control circuit connected or disconnected is in the disconnected state, the device 41, 43, 611, 622 with the control circuit connected or disconnected is in the connected state, the device 511 with the control circuit 511 corresponding to the motor 51 of the auxiliary machine 51 for factory use is in the disconnected state, the device 512 with the control circuit 512 connected or disconnected is in the connected state, the device 522 with the control circuit 522 corresponding to the motor 52 of the auxiliary machine for factory use is in the disconnected state, and the device 521 with the control circuit 521 connected or disconnected is in the connected state. The electric connection relation between the motor 51 of the No. 51 auxiliary plant machine and the No. 11 auxiliary plant bus 11 is in a disconnection state, the electric connection relation between the No. 22 auxiliary plant bus 22 and the industrial power plant electric system 8 is in a disconnection state, the motor 51 of the No. 51 auxiliary plant machine is supplied with electric energy by the electric energy converter 6 through the No. 22 auxiliary plant bus 22, and the motor 52 of the No. 52 auxiliary plant machine is supplied with electric energy by the variable frequency generator 4 through the No. 13 auxiliary plant bus 13;

A method of using the system to assist starting and/or switching of a motor of a plant auxiliary machine: when the device 41, 624, 84 with the control circuit connection or disconnection No. 41, 624, 82 is in the disconnection state, the device 43, 611, 622, 82 with the control circuit connection or disconnection No. 43, 611, 622, 82 is in the connection state, the device 511, 512 with the control circuit connection or disconnection No. 511, 512 corresponding to the motor 51 of the auxiliary machine for factory No. 51 to be started is in the disconnection state, the device 521 with the control circuit connection or disconnection No. 521 corresponding to the motor 52 of the auxiliary machine for factory No. 52 is in the connection state, and the device 522 with the control circuit connection or disconnection No. 522 corresponding to the auxiliary machine for factory No. 522 is in the disconnection state. The electric connection relation between the motor 51 of the auxiliary machine for the factory service number 51 to be started and the factory bus 11 is in a disconnected state, the electric connection relation between the motor 51 of the auxiliary machine for the factory service number 11 and the factory bus 22 is in a disconnected state, the electric energy converter 6 is in an operating state, the power frequency factory power system 8 operates, the motors 52 of the auxiliary machines for the factory service number 52 are supplied with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the factory bus 13 for the factory service number 13;

Detailed description of the invention

As shown in FIG. 3, the present invention provides a specific embodiment of a multi-port power conversion and switching system, which comprises a bus 11 for factory use, a bus 13 for factory use, a bus 22 for factory use, a bus 24 for factory use, a variable frequency generator 4, a small steam turbine 44 for driving the variable frequency generator 4 to generate alternating current with variable frequency, a steam inlet adjusting valve 45 for controlling the steam inlet amount of the small steam turbine 44, a power frequency factory use system 8, a plurality of motors 51 for auxiliary factory use, a plurality of motors 52 for auxiliary factory use 52, and a power converter 6 for adjusting the frequency and/or voltage of at least one connecting end and controlling the power to flow between the factory use buses with different frequencies, or a power converter 6 for controlling the power to flow between the factory use buses with different frequencies and the same frequency, wherein the power converter 6 comprises a connecting end 61, a connecting end 61, No. 62 link 62 and No. 64 link 64, etc. The No. 61 connecting end 61 of the electric energy converter 6 is electrically connected with the No. 13 factory bus 13 through a device 613 for connecting or disconnecting the No. 613 control circuit, the No. 64 connecting end 64 of the electric energy converter 6 is electrically connected with the No. 24 factory bus 24 through a device 624 for connecting or disconnecting the No. 624 control circuit, the variable frequency generator 4 is electrically connected with the No. 11 factory bus 11 through a device 41 for connecting or disconnecting the No. 41 control circuit, the power frequency factory electrical system 8 is electrically connected with the No. 22 factory bus 22 through a device 82 for connecting or disconnecting the No. 82 control circuit, the power frequency factory electrical system 8 is also electrically connected with the No. 24 factory bus 24 through a device 84 for connecting or disconnecting the No. 84 control circuit, the motor 51 of each No. 51 factory auxiliary machine is electrically connected with the No. 11 factory bus 11 through a device 511 for connecting or disconnecting the corresponding to the No. 511 control circuit, and the motor 51 of each No. 51 factory auxiliary machine is electrically connected with the No. 22 through a device 512 for connecting or disconnecting the, the motor 52 of each of the No. 52 auxiliary machines is electrically connected to the No. 13 auxiliary bus 13 through a device 521 that is connected or disconnected by a corresponding control circuit No. 521, and the motor 52 of each of the No. 52 auxiliary machines is electrically connected to the No. 24 auxiliary bus 24 through a device 522 that is connected or disconnected by a corresponding control circuit No. 522.

The system further comprises a No. 743 transformer, the variable frequency generator 4 is electrically connected with the No. 743 transformer, and the No. 743 transformer is electrically connected with the No. 13 station bus 13 through a device 43 for controlling circuit connection or disconnection. After the voltage output by the variable frequency generator 4 is converted by the 743 transformer, the variable frequency generator 4 with different voltage grades can be electrically connected with the 13 # service bus 13.

The intelligent power supply system further comprises No. 711 and No. 722 transformers 711 and 722, the No. 61 connecting end 61 of the electric energy converter 6 is also electrically connected with the No. 711 transformer 711, the No. 62 connecting end 62 of the electric energy converter 6 is also electrically connected with the No. 722 transformer 722, the No. 711 transformer 711 is electrically connected with the No. 11 service bus 11 through a device 611 for controlling circuit connection or disconnection, and the No. 722 transformer 722 is electrically connected with the No. 22 service bus 22 through a device 622 for controlling circuit connection or disconnection. After the voltage of the No. 11 service bus 11 is converted by the No. 711 transformer 711, the No. 11 service bus 11 with different voltage levels can be electrically connected with the electric energy converter 6; after the voltage of the No. 22 service bus 22 is converted by the No. 722 transformer 722, the No. 22 service bus 22 with different voltage grades and the electric energy converter 6 can be electrically connected.

The water supply system also comprises a water supply pump 10 and a number 910 rotating speed conversion device, wherein the small steam turbine 44 drives the variable frequency generator 4 and simultaneously drives the water supply pump 10, the small steam turbine 44 drives the water supply pump 10 through the number 910 rotating speed conversion device 910, and the number 910 rotating speed conversion device 910 can change the corresponding relation of the rotating speeds between the small steam turbine 44 and the water supply pump 10 so as to meet the requirements of different rotating speeds of the water supply pump 10 and the motor of the auxiliary machine for the plant at the same time. The frequency conversion generator 4 and the feed pump 10 share one small turbine 44, so that the investment of the small turbine can be reduced, and the investment cost of a centralized frequency conversion project is obviously reduced.

The system further comprises a motor 251 of the No. 251 auxiliary machine, a motor 451 of the No. 451 auxiliary machine, wherein the motor 251 of the No. 251 auxiliary machine is electrically connected with the No. 22 auxiliary bus 22 through a corresponding device 2512 for controlling circuit connection or disconnection, and the motor 451 of the No. 451 auxiliary machine is electrically connected with the No. 24 auxiliary bus 22 through a corresponding device 4512 for controlling circuit connection or disconnection.

The method for converting electric energy by using the system comprises the following steps: when the devices 41, 611, 622, 624, 511, 2512 and 4512 which control the connection or disconnection of the circuits are in the connected state, the devices 43, 84, 613 and 82 and the devices 43, 84, 613, 82, 512, 521 and 522 which control the connection or disconnection of the circuits are in the disconnected state, No. 43, 611, 624, 511, 2512 and 4512. The variable frequency generator 4 supplies electric energy to the No. 11 plant bus 11, the motors 51 of the multiple No. 51 plant auxiliary machines are supplied with electric energy by the variable frequency generator 4, and the variable frequency operation is carried out on the No. 11 plant bus 11; the variable frequency generator 4 provides electric energy for the No. 22 plant bus 22 through the electric energy converter 6, the motor 251 of the No. 251 plant auxiliary machine provides electric energy through the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operation is carried out on the No. 22 plant bus 22; the variable-frequency generator 4 supplies electric energy to the No. 24 plant bus 24 through the electric energy converter 6, the motor 451 of the No. 451 plant auxiliary machine supplies electric energy through the variable-frequency generator 4 and the electric energy converter 6, and the variable frequency operation is carried out on the No. 24 plant bus 24.

By adjusting the opening degree of the steam inlet adjusting valve 45 and the transmission power of the electric energy converter 6, the variable frequency electric energy of the variable frequency generator 4 is supplied from the No. 11 plant bus 11 to the motor 251 of the No. 251 plant auxiliary machine supplied with power from the No. 22 plant bus 22 and the motor 451 of the No. 451 plant auxiliary machine supplied with power from the No. 24 plant bus 24 through the electric energy converter 6. The frequency of the connecting end is adjusted through the electric energy converter 6, and the running frequency of the No. 11 factory bus 11, the running frequency of the No. 22 factory bus 22 and the running frequency of the No. 24 factory bus 24 can be variable frequency frequencies which are different from each other.

Detailed description of the invention

As shown in FIG. 4, the present invention provides a specific embodiment of a multi-port power conversion and switching system, which comprises a bus 11 for factory use, a bus 13 for factory use, a bus 22 for factory use, a bus 24 for factory use, a variable frequency generator 4, a small steam turbine 44 for driving the variable frequency generator 4 to generate alternating current with variable frequency, a steam inlet adjusting valve 45 for controlling the steam inlet amount of the small steam turbine 44, a power frequency factory use system 8, a plurality of motors 51 for auxiliary factory use, a plurality of motors 52 for auxiliary factory use 52, and a power converter 6 for adjusting the frequency and/or voltage of at least one connecting end and controlling the power to flow between the factory use buses with different frequencies, or a power converter 6 for controlling the power to flow between the factory use buses with different frequencies and the same frequency, wherein the power converter 6 comprises a connecting end 61, a connecting end 61, No. 62 link 62 and No. 64 link 64, etc. A connection terminal 61 No. 61 of the electric energy converter 6 is electrically connected with a station bus 11 No. 11 through a device 611 No. 611 for controlling circuit connection or disconnection, a connection terminal 62 No. 62 of the electric energy converter 6 is electrically connected with a station bus 22 No. 22 through a device 622 No. 622 for controlling circuit connection or disconnection, the variable frequency generator 4 is electrically connected with a station bus 11 No. 11 through a device 41 No. 41 for controlling circuit connection or disconnection, the power frequency station electric system 8 is electrically connected with a station bus 22 No. 22 through a device 82 No. 82 for controlling circuit connection or disconnection, the power frequency station electric system 8 is also electrically connected with a station bus 24 No. 24 through a device 84 No. 84 for controlling circuit connection or disconnection, the motor 51 of each station auxiliary machine No. 51 is electrically connected with the station bus 11 through a device 511 for controlling circuit connection or disconnection, respectively, and the motor 51 of each station auxiliary machine No. 51 is electrically connected with the station bus 22 through a device 512 for controlling circuit connection or disconnection, the motor 52 of each of the No. 52 auxiliary machines is electrically connected to the No. 13 auxiliary bus 13 through a device 521 that is connected or disconnected by a corresponding control circuit No. 521, and the motor 52 of each of the No. 52 auxiliary machines is electrically connected to the No. 24 auxiliary bus 24 through a device 522 that is connected or disconnected by a corresponding control circuit No. 522.

The bus type-61 connecting terminal of the electric energy converter 6 is also electrically connected with the No. 713 transformer 713, the No. 64 connecting terminal 64 of the electric energy converter 6 is electrically connected with the No. 724 transformer 713, the No. 713 transformer 713 is electrically connected with the No. 13 service bus 13 through the device 613 for connecting or disconnecting the No. 613 control circuit, and the No. 724 transformer 724 is electrically connected with the No. 24 service bus 24 through the device 624 for connecting or disconnecting the No. 624 control circuit. After the voltage of the station bus 13 No. 13 is converted by the transformer 713 No. 713, the station bus 13 No. 13 with different voltage levels can be electrically connected with the electric energy converter 6; after the voltage of the 24 # service bus 24 is converted by the 724 # transformer, the 24 # service bus 24 with different voltage grades and the electric energy converter 6 can be electrically connected.

The system also comprises a water feeding pump 10 and a No. 94 rotating speed conversion device 94, the small steam turbine 44 drives the variable frequency generator 4 and simultaneously drives the water feeding pump 10, the small steam turbine 44 drives the variable frequency generator 4 through the No. 94 rotating speed conversion device 94, and the No. 94 rotating speed conversion device 94 can change the corresponding relation of the rotating speeds between the small steam turbine 44 and the variable frequency generator 4 so as to meet the requirements of different rotating speeds of the water feeding pump 10 and the motor of the auxiliary machine for the plant at the same time. The frequency conversion generator 4 and the feed pump 10 share one small turbine 44, so that the investment of the small turbine can be reduced, and the investment cost of a centralized frequency conversion project is obviously reduced.

The 1 st method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of 41, 82, 611, 624 and 511, 522 connected or disconnected are in the connected state, and the devices 43, 84, 613, 622 and 512, 521 with the control circuits of 43, 84, 613, 622, 512, 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

When the load of the main steam turbine generator set is reduced, the power change of the motors 51 and 52 of the multiple auxiliary plant machines 51 and 52 participating in the concentrated variable-frequency operation is smaller, the power change of the steam turbine 44 is more obvious when the steam inlet regulating valve of the steam turbine is in the original opening degree, and the required frequency of the motors 51 and 52 of the multiple auxiliary plant machines 51 and 52 is further reduced. The 622 device for connecting or disconnecting the 622 control circuit is changed into a connection state, and the surplus variable frequency electric energy of the variable frequency generator 4 is converted into power frequency electric energy through the 11 number of plant buses 11 and the electric energy converter 6 by adjusting the transmission power of the electric energy converter 6 and is transmitted to the 22 number of plant buses 22 and the power frequency plant power system 8. The 62 side of the 62 connection end of the electric energy converter 6 runs at the power frequency, and the 64 side of the 64 connection end runs at the frequency conversion frequency. On the one hand, the small steam turbine 44 and the variable frequency generator 4 work in a high-efficiency area, the overall system efficiency is improved, on the other hand, part of electric energy of the variable frequency generator 4 is supplied to the power frequency station power utilization system 8 of the main steam turbine generator unit, the station power utilization rate of direct supply of the main steam turbine generator unit is reduced, the economic benefit is increased, and the energy-saving effect is achieved.

The 2 nd method for converting electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of 41, 82, 611, 624 and 511, 522 connected or disconnected are in the connected state, and the devices 43, 84, 613, 622 and 512, 521 with the control circuits of 43, 84, 613, 622, 512, 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

When the steam inlet regulating valve 45 is in the throttling state, the output power of the small steam turbine 44 is increased by regulating the opening degree of the steam inlet regulating valve 45 of the small steam turbine 44, the throttling loss is reduced or even eliminated, the device 622 for connecting or disconnecting the No. 622 control circuit is changed into the connecting state, the transmission power of the electric energy converter 6 is regulated, and the increased variable frequency electric energy is converted into power frequency electric energy through the electric energy converter 6 and is transmitted to the No. 22 power station bus 22 and the power frequency station power system 8. The 62 side of the 62 connection end of the electric energy converter 6 runs at the power frequency, and the 64 side of the 64 connection end runs at the frequency conversion frequency. On the one hand, the throttling loss is reduced or even eliminated, the transmission power of the small steam turbine 44 is correspondingly increased, the small steam turbine 44 and the variable frequency generator 4 work in a high-efficiency area, the overall efficiency of the system is improved, on the other hand, part of electric energy of the variable frequency generator 4 is supplied to the power frequency station power utilization system 8 of the main steam turbine generator unit, the station power utilization rate of direct supply of the main steam turbine generator unit is reduced, the economic benefit is increased, and the energy-saving effect is achieved.

The 3 rd method for converting the electric energy by using the system comprises the following steps: when the devices 41, 82, 611, 624, 522 with the control circuits of 41, 82, 611, 624 and 511, 522 connected or disconnected are in the connected state, and the devices 43, 84, 613, 622 and 512, 521 with the control circuits of 43, 84, 613, 622, 512, 521 connected or disconnected are in the disconnected state. The power frequency power plant power system 8 operates, the variable frequency generator 4 provides electric energy to the No. 11 power plant bus 11, the motors 51 of the multiple No. 51 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4, the variable frequency operates in the No. 11 power plant bus 11, the variable frequency generator 4 provides electric energy to the No. 24 power plant bus 24 through the No. 64 connecting end 64 of the electric energy converter 6, the motors 52 of the multiple No. 52 power plant auxiliary machines are provided with electric energy by the variable frequency generator 4 through the electric energy converter 6, and the variable frequency operates in the No. 24 power plant bus 24.

The device 622 for connecting or disconnecting the No. 622 control circuit is changed into a connection state, and power frequency electric energy from the power frequency plant electric system 8 is converted into variable frequency electric energy from the No. 22 plant bus 22 through the electric energy converter 6 and is conveyed to the No. 11 plant bus 11 and the No. 24 plant bus 24 by adjusting the conveying power of the electric energy converter 6. The 62 side of the 62 connection end of the electric energy converter 6 runs at the power frequency, and the 64 side of the 64 connection end runs at the frequency conversion frequency. The electric power of the power frequency plant power system 8 of the main steam turbine generator set is supplied to the motors 51 and 52 of the plurality of No. 51 and No. 52 plant auxiliary machines, so that on one hand, the design allowance of the capacity of the variable frequency generator 4 can be reduced, the investment cost is reduced, and on the other hand, the bottleneck of insufficient steam intake of the small steam turbine 44 can be relieved. When the variable-frequency generator 4 or the small turbine 44 needs to quit operation due to maintenance or failure, the motors 51 and 52 of the multiple No. 51 and No. 52 auxiliary plant machines can continue to provide electric energy with variable frequency from the power system 8 of the industrial power plant through the electric energy converter 6.

Specific embodiments of the present invention have been described above in detail. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the teachings of this invention without undue experimentation. Therefore, the technical solutions that can be obtained by a person skilled in the art through logic analysis, reasoning or limited experiments based on the prior art according to the concepts of the present invention should be within the scope of protection defined by the claims.

Claims

1. A novel multiport electric energy conversion and switching system comprises a No. 11 factory bus (11), a No. 22 factory bus (22), a No. 24 factory bus (24), a variable frequency generator (4), at least one motor (51) of a No. 51 factory auxiliary machine, at least one motor (52) of a No. 52 factory auxiliary machine, a small steam turbine (44) for driving the variable frequency generator (4) to send alternating current with variable frequency, a steam inlet adjusting valve (45) for controlling the steam inlet quantity of the small steam turbine (44), and a power frequency factory electrical system (8), wherein the variable frequency generator (4) provides electric energy for the No. 11 factory bus (11), and is characterized by further comprising an electric energy converter (6) capable of adjusting the frequency and/or voltage of at least one connecting end and controlling the electric energy to flow between the factory buses with different frequencies, or controlling the electric energy to flow between the factory buses with the same frequency at different frequencies, electric energy converter (6) include No. 61 link (61), No. 62 link (62) and No. 64 link (64), No. 61 link (61) of electric energy converter (6) with No. 11 mill buses (11) are electrically connected, No. 62 link (62) of electric energy converter (6) with No. 22 mill buses (22) are electrically connected, No. 64 link (64) of electric energy converter (6) with No. 24 mill buses (24) are electrically connected, No. 62 link (62) side of electric energy converter (6) and No. 64 link (64) side of electric energy converter (6) can operate at different frequencies, motor (51) of No. 51 mill auxiliary machinery with No. 11 mill buses (11) are electrically connected, motor (51) of No. 51 mill auxiliary machinery with No. 22 mill buses (22) are electrically connected, motor (52) of No. 52 factory auxiliary engine with No. 11 factory bus (11) electricity is connected, motor (52) of No. 52 factory auxiliary engine with No. 24 factory bus (24) electricity is connected, power frequency factory power consumption system (8) with No. 22 factory bus (22), and/or, with No. 24 factory bus (24) electricity is connected, electrical connection can be in switch on and break off two kinds of states.

2. The novel multiport electric energy conversion and switching system according to claim 1, further comprises at least one 251 auxiliary factory machine motor (251) and/or at least one 451 auxiliary factory machine motor (451), wherein the 251 auxiliary factory machine motor (251) is electrically connected with the 22 auxiliary factory bus (22), and/or the 451 auxiliary factory machine motor (451) is electrically connected with the 24 auxiliary factory bus (24), and the electrical connection relationship can be in on and off states.

3. A novel multiport electric energy conversion and switching system according to claim 1, wherein the amount of the transmission power of said electric energy converter (6) can be controlled autonomously, and the electric energy flowing direction between any two connection terminals of said electric energy converter (6) can be unidirectional or bidirectional.

4. The new multiport electrical energy conversion and switching system of claim 1 further comprising a 722-size transformer (722), and/or a 724-size transformer (724);

no. 62 connecting ends (62) of the electric energy converter (6) pass through the No. 722 transformer (722) and the No. 22 service bus (22) are electrically connected, and/or No. 64 connecting ends (64) of the electric energy converter (6) pass through the No. 724 transformer (724) and the No. 24 service bus (24) are electrically connected, and the electric connection relation can be in two states of conduction and disconnection.

5. A novel multiport electric energy conversion and switching system according to any of claims 1-4, characterized in that said small steam turbine (44) directly drives said variable frequency generator (4), or further comprises a number 94 of rotational speed conversion devices (94), said small steam turbine (44) drives said variable frequency generator (4) through said number 94 of rotational speed conversion devices (94), said number 94 of rotational speed conversion devices (94) can change the corresponding relationship of the rotational speeds between said small steam turbine (44) and said variable frequency generator (4).

6. A novel multiport electric energy conversion and switching system according to any of claims 1 to 4, characterized by further comprising a feed water pump (10), said small turbine (44) driving said variable frequency generator (4) and driving said feed water pump (10).

7. A novel multiport electric energy conversion and switching system according to claim 5, characterized in that it further comprises a feed water pump (10), said small turbine (44) driving said variable frequency generator (4) while driving said feed water pump (10).

8. The new multiport electric energy conversion and switching system according to claim 6, further comprising number 910 of rotational speed conversion devices, wherein one end of the rotating shaft of said small steam turbine (44) drives said variable frequency generator (4), and the other end of the rotating shaft of said small steam turbine (44) drives said feed pump (10) through said number 910 of rotational speed conversion devices (910).

9. The new multiport electric energy conversion and switching system according to claim 7, further comprising number 910 of rotational speed conversion devices, wherein one end of the rotating shaft of said small steam turbine (44) drives said variable frequency generator (4), and the other end of the rotating shaft of said small steam turbine (44) drives said feed pump (10) through said number 910 of rotational speed conversion devices (910).

10. The new multiport electrical energy conversion and switching system of claim 5 wherein said number 94 rotational speed changing device (94) can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

11. The new multiport electrical energy conversion and switching system of claim 7 wherein said number 94 rotational speed changing device (94) can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

12. The new multiport electrical energy conversion and switching system of claim 8, wherein said number 910 rotational speed changing device can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

13. The new multiport electrical energy conversion and switching system of claim 9, wherein said number 94 rotational speed changing device (94) and said number 910 rotational speed changing device (910) can be fluid couplings, gear boxes, magnetic couplings, or combinations thereof.

14. A novel multiport electric energy conversion and switching system comprises a bus (11) for factory use, a bus (13) for factory use, a bus (22) for factory use, a bus (24) for factory use, a variable frequency generator (4), at least one motor (51) for auxiliary machine for factory use, at least one motor (52) for auxiliary machine for factory use, a small steam turbine (44) for driving the variable frequency generator (4) to send alternating current with variable frequency, a steam inlet adjusting valve (45) for controlling the steam inlet amount of the small steam turbine (44), and an electric system (8) for industrial frequency factory use, wherein the variable frequency generator (4) provides electric energy for the bus (11) for factory use and the bus (13) for factory use, and is characterized by further comprising a frequency and/or voltage which can adjust at least one connecting end, and controls the electric energy to flow between the bus for factory use with different frequencies, or, can control electric energy and can control electric energy at the electric energy converter (6) that the electric energy flows between the station bus of same frequency again in different frequencies, electric energy converter (6) includes No. 61 link (61), No. 62 link (62) and No. 64 link (64), No. 61 link (61) of electric energy converter (6) with No. 11 station bus (11) electricity is connected, No. 62 link (62) of electric energy converter (6) with No. 22 station bus (22) electricity is connected, No. 64 link (64) of electric energy converter (6) with No. 24 station bus (24) electricity is connected, No. 62 link (62) side of electric energy converter (6) and No. 64 link (64) side of electric energy converter (6) can operate at different frequencies, No. 51 station auxiliary machine's motor (51) with No. 11 station bus (11) electricity is connected, motor (51) of No. 51 factory auxiliary engine with No. 22 factory bus (22) electricity is connected, motor (52) of No. 52 factory auxiliary engine with No. 13 factory bus (13) electricity is connected, motor (52) of No. 52 factory auxiliary engine with No. 24 factory bus (24) electricity is connected, power frequency factory with electrical system (8) with No. 22 factory bus (22), and/or, with No. 24 factory bus (24) electricity is connected, electrical connection can be in switch on and break off two kinds of states.

15. A novel multiport electric energy conversion and switching system according to claim 14, characterized in that the No. 61 connecting terminal (61) of said electric energy converter (6) is also electrically connected with said No. 13 service bus (13), and the electrical connection can be in two states of on and off.

16. A novel multiport electric energy conversion and switching system according to claim 14, characterized by further comprising at least one motor (251) of No. 251 auxiliary factory machine, and/or at least one motor (451) of No. 451 auxiliary factory machine, wherein the motor (251) of No. 251 auxiliary factory machine is electrically connected with the No. 22 auxiliary factory bus (22), and/or the motor (451) of No. 451 auxiliary factory machine is electrically connected with the No. 24 auxiliary factory bus (24), and the electrical connection relationship can be in two states of on and off.

17. A novel multiport electric energy conversion and switching system according to claim 15, further comprising at least one motor (251) of No. 251 auxiliary factory machine, and/or at least one motor (451) of No. 451 auxiliary factory machine, wherein the motor (251) of No. 251 auxiliary factory machine is electrically connected with the No. 22 auxiliary bus (22), and/or the motor (451) of No. 451 auxiliary factory machine is electrically connected with the No. 24 auxiliary bus (24), and the electrical connection relationship can be in two states of on and off.

18. A novel multiport electric energy conversion and switching system according to claim 14, characterized in that the amount of the transmitted power of said electric energy converter (6) can be controlled autonomously, and the electric energy flowing direction between any two connection terminals of said electric energy converter (6) can be unidirectional or bidirectional.

19. A novel multiport electric energy conversion and switching system according to claim 15, characterized in that the amount of the transmitted power of said electric energy converter (6) can be controlled autonomously, and the electric energy flowing direction between any two connecting terminals of said electric energy converter (6) can be unidirectional or bidirectional.

20. The novel multiport electric energy conversion and switching system according to claim 14, further comprises a 741 transformer (741) or an 743 transformer (743), wherein the variable frequency generator (4) is electrically connected to the 11 station bus (11) through the 741 transformer (741) or the variable frequency generator (4) is electrically connected to the 13 station bus (13) through the 743 transformer (743), and the electrical connection can be in two states of on and off.

21. The novel multiport electric energy conversion and switching system according to claim 15, further comprises a 741 transformer (741) or an 743 transformer (743), wherein the variable frequency generator (4) is electrically connected to the 11 station bus (11) through the 741 transformer (741) or the variable frequency generator (4) is electrically connected to the 13 station bus (13) through the 743 transformer (743), and the electrical connection can be in two states of on and off.

22. The novel multiport electrical energy conversion and switching system of claim 20 further comprising a 711 transformer (711), or a 713 transformer (713), or a 71113 three-winding transformer (71113);

no. 61 link (61) of electric energy converter (6) passes through No. 711 transformer (711) with No. 11 mill is with bus (11) electricity connection, perhaps, No. 61 link (61) of electric energy converter (6) passes through No. 713 transformer (713) with No. 13 mill is with bus (13) electricity connection, or, the three winding of No. 71113 three-winding transformer (71113) respectively with No. 11 mill is with bus (11), No. 13 mill is with bus (13) with No. 61 link (61) of electric energy converter (6) electricity connection, electrical connection can be in and switch on and off two kinds of states.

23. The novel multiport electrical energy conversion and switching system of claim 21 further comprising a 711 transformer (711), or a 713 transformer (713), or a 71113 three-winding transformer (71113);

24. The new multiport electrical energy conversion and switching system according to claim 20, further comprising two transformers 711 and 722 (711), (722), or further comprising two transformers 713 and 724 (713), (724);

the No. 61 connecting end (61) of the electric energy converter (6) is electrically connected with the No. 11 service bus (11) through the No. 711 transformer (711), and the No. 62 connecting end (62) of the electric energy converter (6) is electrically connected with the No. 22 service bus (22) through the No. 722 transformer (722);

or,

the No. 61 connecting end (61) of the electric energy converter (6) is electrically connected with the No. 13 service bus (13) through the No. 713 transformer (713), and the No. 64 connecting end (64) of the electric energy converter (6) is electrically connected with the No. 24 service bus (24) through the No. 724 transformer (724); the electrical connection can be in both on and off states.

25. The new multiport electrical energy conversion and switching system according to claim 21 further comprising two transformers 711 and 722 (711), (722) or further comprising two transformers 713 and 724 (713), (724);

or,

26. The new multiport electrical energy conversion and switching system of claim 14 further comprising a 722-size transformer (722), and/or a 724-size transformer (724);

27. The new multiport electrical energy conversion and switching system of claim 15 further comprising a 722-size transformer (722), and/or a 724-size transformer (724);

28. A novel multiport electric energy conversion and switching system according to any of claims 14-27, characterized in that said small steam turbine (44) directly drives said variable frequency generator (4), or further comprises a number 94 of rotational speed conversion devices (94), said small steam turbine (44) drives said variable frequency generator (4) through said number 94 of rotational speed conversion devices (94), said number 94 of rotational speed conversion devices (94) can change the corresponding relationship of the rotational speed between said small steam turbine (44) and said variable frequency generator (4).

29. A novel multiport electric energy conversion and switching system according to any of claims 14 to 27, further comprising a feed water pump (10), said small turbine (44) driving said variable frequency generator (4) and driving said feed water pump (10).

30. The new multiport electrical energy conversion and switching system according to claim 28 further comprising a feed water pump (10), said small turbine (44) driving said variable frequency generator (4) while driving said feed water pump (10).

31. A novel multiport electric energy conversion and switching system according to claim 29, further comprising number 910 of rotational speed conversion devices, wherein one end of the rotating shaft of said small steam turbine (44) drives said variable frequency generator (4), and the other end of the rotating shaft of said small steam turbine (44) drives said feed pump (10) through said number 910 of rotational speed conversion devices (910).

32. The new multiport electric energy conversion and switching system according to claim 30, further comprising number 910 of rotational speed conversion devices, wherein one end of the rotating shaft of said small steam turbine (44) drives said variable frequency generator (4), and the other end of the rotating shaft of said small steam turbine (44) drives said feed pump (10) through said number 910 of rotational speed conversion devices (910).

33. The new multiport electrical energy conversion and switching system of claim 28 wherein said number 94 rotational speed changing device (94) can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

34. The new multiport electrical energy conversion and switching system of claim 30 wherein said number 94 rotational speed changing device (94) can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

35. The new multiport electrical energy conversion and switching system of claim 31 wherein said number 910 speed changer can be a fluid coupling, a gear box, a magnetic coupling, or a combination of each other.

36. The new multiport electrical energy conversion and switching system of claim 32 wherein said number 94 rotational speed conversion device (94) and said number 910 rotational speed conversion device (910) may be fluid couplings, gear boxes, magnetic couplings, or combinations thereof.