CN107846042A - A kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability - Google Patents
A kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability Download PDFInfo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
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Abstract
A kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability, including：Low-voltage ride-through method：In electric power incoming line Voltage Drop, provide dc source by inverter of the low-voltage crossing electric capacity into frequency converter and support.High voltage crossing method：When frequency converter inlet wire alternating voltage is rapidly increased to the rated voltage level above, voltage is limited in a manner of copped wave of consuming energy.Thus solve failure present in prior art and frequent, equipment manufacturing cost costliness, the technical problem that algorithm complexity is cumbersome, safe and stable operation to power network and generating set brings serious harm occurs.The inventive method control loop is simple, response is rapid, and the safe and stable operation for improving thermal power plant and power network is horizontal.
Description
Technical field
It is special the invention belongs to the high voltage crossing in high-power electric and electronic technology and low voltage ride-through capability testing field
It is not related to a kind of technical method for the high-low voltage ride-through capability for improving fossil power plant auxiliary engine frequency converter.
Background technology
Generally, short circuit can often occur in bulk power grid or other failures cause the rising sharply of system voltage, rapid drawdown, if trouble point is sent out
It is raw in 300MW and the key element of above large thermal power plant, as fired power generating unit subsidiary engine frequency converter near, it is likely that cause
Subsidiary engine frequency converter trips, and further resulting in blowing out causes generating set to send off-grid event, is caused to the power network under failure
Another Secondary Shocks, deteriorate the safety and stability level of power system, and the safe and stable operation to power system brings great threat.
Therefore, a kind of technical method for improving fossil power plant auxiliary engine frequency converter high and low pressure ride-through capability is studied to be advantageous to improve whole electricity
Net safety and stability is horizontal, avoids the shutdown that fired power generating unit is unnecessary, has great economic implications to society.
At present for the research of fired power generating unit one kind subsidiary engine frequency converter low voltage crossing, to improving fired power generating unit one kind subsidiary engine
The technical scheme of frequency converter low voltage ride-through capability mainly includes：DC/DC technical supports scheme, online series connection uninterrupted power source side
Case, dual power supply handover scheme and dynamic electric voltage recovery device scheme etc..Online series connection uninterrupted power source capacity is small, conversion efficiency
It is low, protection level is high, cost of investment is high, if online series connection uninterrupted power source in itself there occurs failure, directly influence frequency converter
Normal work, thus the application of online series connection uninterrupted power source is restricted.Dual power supply handover scheme and dynamic electric voltage
Restorer scheme is started with from the enter line side of frequency converter to improve its low voltage ride-through capability, and system is mainly by energy-storage module, inversion
The compositions such as module, detection circuit, control circuit.But it is controlled by it the complexity, relatively expensive price, less capacity of algorithm
Etc. influence, the application of dual power supply handover scheme and dynamic electric voltage recovery device scheme receives certain limitation.
In terms of the research of fired power generating unit one kind subsidiary engine frequency converter high voltage crossing, China promulgates《Quality of power supply voltage
Temporarily liter, temporarily drop and short interruptions》Technical requirements specification.System voltage is explicitly pointed out in specification and is temporarily risen and refers to certain point in power system
Power frequency root-mean-square valve temporarily rises to 1.1~1.8p.u., and recovers normal phenomenon after last for short 10ms~1min.Have
When electric network fault short time voltage can be caused to raise, for example line voltage declines and causes to lose load suddenly, and then causes voltage
Suddenly single-pole reclosing caused by rise, singlephase earth fault can trigger power network asymmetrical three-phase high pressure, grid voltage sags event
Also it can trigger rising sharply for line voltage because input capacitive compensator can not exit in time in recovery process after barrier removing.
Generator subsidiary engine frequency converter chaser can be caused when line voltage is increased to certain value, if institute's chaser group is crucial subsidiary engine, had
MFT may be caused, the safe and stable operation to power network and generating set brings serious harm.
The content of the invention
The present invention proposes a kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability.Wherein, low-voltage
Traversing method：In electric power incoming line Voltage Drop, dc source is provided by inverter of the low-voltage crossing electric capacity into frequency converter
Support.High voltage crossing method：When frequency converter inlet wire alternating voltage is rapidly increased to the rated voltage level above, with power consumption
The mode of copped wave limits voltage.Thus solve present in prior art that failure occurs frequently, equipment manufacturing cost is expensive, algorithm is multiple
Miscellaneous cumbersome, safe and stable operation to power network and generating set brings the technical problem of serious harm.
The technical solution adopted by the present invention is：A kind of side for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability
Method, it is characterised in that：
1), low-voltage ride-through method：It is inverse into frequency converter by low-voltage crossing electric capacity in electric power incoming line Voltage Drop
Become device and dc source support is provided, be specially：
Low-voltage crossing electric capacity is equipped with frequency converter DC side, the terminal voltage of its low-voltage crossing electric capacity is less than frequency converter direct current
Pressure value, series opposing diode between frequency converter DC side and low-voltage crossing electric capacity；When fossil power plant auxiliary engine frequency converter inlet wire electricity
When pressure value declines, low-voltage crossing electric capacity provides DC energy using fly-wheel diode as passage, to inverter, makes frequency converter certain
Time in keep stable operation；
2), high voltage crossing method：When frequency converter inlet wire alternating voltage is rapidly increased to the rated voltage level above, with
The mode of power consumption copped wave limits voltage, is specially：Detection circuit is provided with power network bus, by braking resistor R and load Rl simultaneously
Connection, and pass through electronic switch S control braking resistors R access and disengaging；When the detection electric circuit inspection on bus to line voltage
Hinder for some reason and moment raise when, electronic switch S closure, make braking resistor R access operation；When line voltage is normal, electronic cutting
Close S to disconnect, make braking resistor R out of service.
It is described 1) in, the highest terminal voltage value of bulky capacitor should be less than the rated value of frequency converter DC side busbar voltage.
It is described 1) in, low-voltage crossing capacitance is 0-100 μ f；Low-voltage crossing electric capacity under the conditions of this is considered as linear
Energy storage original paper, the terminal voltage of its electric capacity and discharge time are into linear dependence.
It is described 2) in, DC voltage that detection circuit is had a try on detection bus, and determine DirectCurrent Voltage Ratio with frequency converter heat
Relatively reach difference, by PI controllers, control the dutycycle of IGBT in electronic switch S, leading to for electronic switch S is controlled so as to control
Disconnected state.
The beneficial effects of the invention are as follows：
The present invention is a kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability.Wherein, low-voltage is worn
More method：In electric power incoming line Voltage Drop, dc source branch is provided by inverter of the low-voltage crossing electric capacity into frequency converter
Support.High voltage crossing method：Rapidly it is increased to a certain degree, limit in a manner of copped wave of consuming energy when frequency converter inlet wire alternating voltage rises
Voltage processed.This method establishes low-voltage crossing electric capacity mathematical modeling；According to power plant's actual parameter, to improve fossil power plant auxiliary engine frequency conversion
Device low voltage ride-through capability is goal condition, formulates the corresponding low voltage crossing technical side based on the support of low-voltage crossing electric capacity
Case；To improve fossil power plant auxiliary engine frequency converter high voltage crossing ability as goal condition, energy-dissipating type high voltage crossing scheme is formulated.
This method provides optimal technological invention scheme to improve fossil power plant auxiliary engine high and low pressure fault ride-through capacity as final goal,
The safe and stable operation for improving thermal power plant and power network is horizontal.
Brief description of the drawings
Fig. 1：Charging interval and charging current relation curve.
Fig. 2：Low-voltage crossing electric capacity discharging model.
Fig. 3：Low-voltage crossing electric capacity and discharge time characteristic curve.
Fig. 4：High voltage crossing scheme equivalent circuit diagram.
Embodiment
A kind of method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability, it is characterised in that：
1), low-voltage ride-through method：It is inverse into frequency converter by low-voltage crossing electric capacity in electric power incoming line Voltage Drop
Become device and dc source support is provided, be specially：
Low-voltage crossing electric capacity is equipped with frequency converter DC side, the terminal voltage of its low-voltage crossing electric capacity is less than frequency converter direct current
Pressure value, series opposing diode between frequency converter DC side and low-voltage crossing electric capacity；When fossil power plant auxiliary engine frequency converter inlet wire electricity
When pressure value declines, low-voltage crossing electric capacity provides DC energy using fly-wheel diode as passage, to inverter, makes frequency converter certain
Time in keep stable operation；
2), high voltage crossing method：When frequency converter inlet wire alternating voltage is rapidly increased to the rated voltage level above, with
The mode of power consumption copped wave limits voltage, is specially：
Detection circuit is provided with power network bus, braking resistor R is in parallel with load Rl, and controlled by electronic switch S
Braking resistor R access and disengaging；When the detection electric circuit inspection on bus hinders for some reason to line voltage and moment raises, electronics
S closures are switched, make braking resistor R access operations；When line voltage is normal, electronic switch S disconnects, and exits braking resistor R
Operation.
It is described 1) in, the highest terminal voltage value of bulky capacitor should be less than the rated value of frequency converter DC side busbar voltage.
It is described 1) in, low-voltage crossing capacitance most 0-100 μ f；Low-voltage crossing electric capacity under the conditions of this is considered as line
Shape energy storage original paper, the terminal voltage of its electric capacity and discharge time are into linear dependence.
It is described 2) in, DC voltage that detection circuit is had a try on detection bus, and determine DirectCurrent Voltage Ratio with frequency converter heat
Relatively reach difference, by PI controllers, control the dutycycle of IGBT in electronic switch S, leading to for electronic switch S is controlled so as to control
Disconnected state.
Concrete analysis process：
A kind of technical method for improving fossil power plant auxiliary engine frequency converter high and low pressure ride-through capability, by based on bulky capacitor
The low voltage crossing scheme and energy-dissipating type high voltage crossing scheme of support are designed, and of the invention is designed with beneficial to fired power generating unit
In grid collapses can reliability service, for ensure power network and fired power generating unit stable operation there are most important theories and reality
Value is trampled, is had important practical significance for improving bulk power grid safety and reducing national economy loss, it is characterised in that：The party
Method step is as follows：
1st, low-voltage crossing electric capacity discharging model is established, and this electric capacity is the electric capacity that capacity is 0-100 μ f, hereinafter referred to as big electricity
Hold.Compared with traditional electrochemical cell, the operation principle of bulky capacitor differs widely, and its charge and discharge process happens is that physics becomes
Change, bulky capacitor is a kind of linear element, it can be seen from bulky capacitor energy storage characteristic, with increasing for its storage inside electric charge, its end electricity
Pressure is gradually increasing.Equivalent series resistance ResPresence be inevitable, so when bulky capacitor discharge and recharge, electric current flows through Res
Pressure drop will be produced.Ultracapacitor classical model is charged according to current constant mode, if constant-current charge current value is Is,
Super capacitor initial voltage is 0V, rated voltage UN, charging interval t, terminal voltage is U (t), the electricity that its internal charge is formed
Appearance voltage is Uc(t).Then have：
U (t)=Uc(t)+Res*Is (1)
In bulky capacitor charging process, if loss is in upper electric energy, the dominant loss when thermal losses is charging, its
Calculating formula is：
Ws=Is 2*Res*t (2)
After bulky capacitor charging terminates, its terminal voltage is rated value, if the charging current in charging process is i, so can
The relational expression in charging current and charging interval is expressed as：
It can finally obtain：
2nd, bulky capacitor flash-over characteristic is analyzed：Charging interval can reduce with the increase of charging current, charging current and time
Relation curve as shown in Figure 1.
Charging current and the relational expression consumed between upper energy are represented by：
Ws=CF*Is*Res*(UN-Res*Is) (6)
From above formula, energy loss W in charging processsWith charging current IsIt is quadratic function relation, rather than simply
Inverse ratio or direct ratio functional relation.When bulky capacitor voltage reaches rated value, if bulky capacitor storage energy is Wc, then the expression of energy
Formula is
Using the bulky capacitor model shown in Fig. 2 as reference, as equivalent parallel impedance RepWhen being far longer than equivalent load resistance,
The influence of equivalent parallel impedance can be ignored when bulky capacitor discharges.In order to further simplify to super capacitor in engineer applied
Analysis, the classical model of bulky capacitor can be further simplified as an electric capacity and a R as depictedesThe model being in series.
It can be seen from above formula, when bulky capacitor is in discharge condition, discharge current and equivalent series resistance determine end electricity
The size of pressure.When in low discharging current state, ResPressure drop is very small, can ignore in follow-up calculating process, will big electricity
Appearance is equivalent to ideal capacitor.In the case of heavy-current discharge, ResOn pressure drop can not be ignored.From the foregoing, by Res's
Influence, in the latter stage of bulky capacitor electric discharge, bulky capacitor still has larger terminal voltage value Uc(t).In this case, in bulky capacitor
The energy stored discharges completely, meanwhile, the discharging efficiency of bulky capacitor is also dropped because of the presence of equivalent series resistance
It is low.Therefore, bulky capacitor can be considered as to linear energy-storage travelling wave tube, under a certain degree of discharge current value, the terminal voltage of bulky capacitor with
Discharge time is linear, as shown in Figure 3.
3rd, the present invention devises the low voltage crossing scheme based on bulky capacitor support, using subsidiary engine frequency converter DC link to grind
Study carefully object, the bulky capacitor of suitable capacity is equipped with frequency converter DC side, in electric power incoming line Voltage Drop, bulky capacitor is to frequency converter
Inverter provides dc source support, is specifically described as：
When the power supply of power network AC is normal, subsidiary engine frequency converter is powered by three-phase alternating-current supply, by the end electricity of bulky capacitor
Pressure is set smaller than frequency converter DC voltage value, and bulky capacitor is located at energy storage state, it is impossible to output current；In fossil power plant auxiliary engine
When frequency converter primary voltage value declines, bulky capacitor DC voltage value is more than subsidiary engine frequency changer direct current bus magnitude of voltage, now big electricity
Hold using fly-wheel diode as passage, provide DC energy to inverter, frequency converter can be made to keep steady in certain period of time
Fixed operation.The series opposing diode between the DC side and bulky capacitor of fossil power plant auxiliary engine frequency converter, can avoid subsidiary engine from becoming
Frequency device rectification side bears overload problem caused by additional bulky capacitor charging current.The voltage level of bulk power grid is in normal mode
Under there is also compared with minor swing, this can cause DC voltage value to change therewith.If bulky capacitor combination voltage is arranged to
Busbar voltage rated value, bulky capacitor frequently discharge and recharge can be made.In frequently charge and discharge process, the charhing unit of bulk power grid with
Startup, on the one hand have impact on the security and stability of power system, on the other hand can shorten the service life of bulky capacitor.To understand
Certainly above mentioned problem, the highest terminal voltage value of bulky capacitor should be less than the rated value of frequency converter DC side busbar voltage.
4th, the present invention devises a kind of energy-dissipating type high voltage crossing technical scheme.So-called high voltage crossing, it is exactly power network hair
It is raw abnormal, cause frequency converter inlet wire alternating voltage to be increased to a certain degree, and in the case of certain time, frequency converter is not jumped
Machine.The present invention design the configuration of frequency converter DC link unload can the control of copped wave resistor proposal is simple, it is convenient to realize, and for
Cost is cheap for thermal power plant.
When power plant's primary voltage rapidly rises, high voltage is limited in a manner of copped wave of consuming energy, thermal motor is improved with this
The ability of the high voltage crossing of group subsidiary engine frequency converter.Its operation principle is：When line voltage is normal, electronic switch S open circuits, system
Dynamic resistance R is in state out of service, departs from system and contacts；When line voltage hinders for some reason and moment raises suddenly, S is switched
Closure, braking resistor R (also referred to as energy consumption resistance) is put into operation, it is in parallel with equivalent load resistance, because energy consumption resistor has
Larger power consumption power, the electric current rise on dc bus, then the ohmically pressure drop of load equivalent reduces, therefore is thrown in braking resistor
Enter rear DC bus-bar voltage to be cut down.The input of energy consumption resistor is controlled by electronic power switch S with exiting, and S control is believed
Number come from the detection circuit of busbar voltage.To simplify the analysis and computing, energy consumption type high voltage crossing principle are as shown in Figure 4.
5th, frequency converter rectification output equivalent is that direct voltage source and power supply equivalent internal resistance r are in series, Converting Unit with it is electronic
Machine can be equivalent to load resistance.Have when switching S open circuits：
U-I*r=RL*I (8)
Udc=RL*I (9)
When the switch s is closed,
It can be obtained according to above formula：
Generally, when R value is smaller, the performance number that braking resistor R is consumed is then larger.When switch S closures
When, braking resistor R both end voltages are Udc, electric current will increase moment.U is understood according to above formuladcDecline.Therefore frequency converter inlet wire is worked as
When voltage raises, the braking resistor R of appropriate power, the voltage that frequency converter DC voltage control be able to can be run in frequency converter are put into
In the range of.
6th, in order to solve the problems, such as real-time tracking grid voltage change, the present invention devises DC voltage detection and switch control
Method.It is specifically described as：The suddenly change of three-phase alternating voltage in power network, can be directly anti-in the direct current side bus of frequency converter
Reflect, the real-time detection frequency changer direct current bus Voltage Technique designed by the present invention, control the break-make of electronic power switch, improve
The high voltage crossing ability of frequency converter.The present invention uses the average value of frequency converter DC tache voltage, to being sampled in the fixed cycle
Value average available：
In above formula, N is the voltage sample number in the fixed cycle, is the voltage sample value of ith.Sample obtained voltage
Compared with frequency converter rated direct voltage, electronic power switch S control signal is obtained.It is specifically described as：When voltage reaches
During frequency converter overvoltage protection value, start DC voltage control, caused control signal triggers electronic power switch S, and foundation
The difference of the DC voltage detected in real time and frequency converter rated direct voltage, control to obtain the dutycycle of IGBT in S by PI,
For controlling switch S switching.
7th, DC voltage detection and switching system input, exit criterion.When line voltage is in normal operating condition,
Unload energy copped wave resistance and be in bypass condition, with isolation of system；When grid collapses cause system voltage to raise suddenly, now
Subsidiary engine frequency converter DC voltage can be caused to raise, voltage detection module real-time tracking high voltage signal, pass through additional control circuit
Controlling switch S is closed, and energy-consumption braking resistance is arranged into normal operating conditions.Electronic power switch is controlled using PI control modes
S break-make, energy-consumption braking resistance is set quickly to put into and exit.Ensure that DC bus-bar voltage is limited during three-phase voltage raises
Make in reduced levels, to maintain frequency converter that chaser action does not occur because of overtension.By theory analysis, it is determined that putting into, moving back
It is as follows to go out strategy.Input strategy is：The frequency converter DC voltage value detected to detection module judges, if the electricity detected
Pressure value is higher than setting value, starts control module, makes S in the conduction state, energy-consumption braking resistance is put into.Cutting off strategy is：If
When the value of three-phase primary voltage is less than setting value, electronic power switch S disconnects, and exits the input of energy consumption resistor.
Its general principle is as follows：
It is a kind of improve fossil power plant auxiliary engine frequency converter high and low pressure ride-through capability the cardinal principle of technical method be：Carrying
In terms of rising subsidiary engine frequency converter low voltage ride-through capability, when the power supply of power network AC is normal, subsidiary engine frequency converter passes through three-phase alternating current
Power supply is powered, and the terminal voltage of bulky capacitor is set smaller than into frequency converter DC voltage value, bulky capacitor is located at energy storage state, it is impossible to
Output current；When fossil power plant auxiliary engine frequency converter primary voltage value declines, bulky capacitor DC voltage value is more than subsidiary engine frequency converter
D-c bus voltage value, now bulky capacitor is using fly-wheel diode as passage, provides DC energy to inverter, can make frequency converter
Stable operation is kept in certain period of time.In terms of subsidiary engine frequency converter high voltage crossing ability is lifted, when line voltage just
Chang Shi, electronic switch S open a way, and braking resistor R is in and exits state, is not involved in the operation of system；When line voltage because abnormal and
When raising suddenly, switch S closures, braking resistor input is in parallel with equivalent load resistance, because energy consumption resistor has larger power consumption work(
Rate, the electric current on dc bus will raise, then the ohmically pressure drop of load equivalent reduces, therefore direct current is female after braking resistor input
Line voltage can be cut down.The input of energy consumption resistor is controlled by electronic power switch S with exiting, and S control signal comes from mother
The detection circuit of line voltage.
In present embodiment, energy is passed through using high and low pressure proposed by the invention in certain actual Controlling Auxiliaries in Power Plants frequency converter
The technical method of power.After technical method proposed by the present invention, fired power generating unit can be kept under grid collapses mode
Safe and stable operation, for ensureing that the stable operation of power network and fired power generating unit has most important theories and more practical value.Above-mentioned raising
The technical method of fossil power plant auxiliary engine frequency converter high and low pressure ride-through capability, comprises the following steps：
Step 1：According to the situation of actual Controlling Auxiliaries in Power Plants frequency converter, bulky capacitor mathematical modeling is established.In practical engineering application
In, bulky capacitor equivalent model need to be reduced to limited RC series and parallel branch roads, to simplify the analysis to super capacitor, will can transmit
Line model is equivalent to a RC subcircuits.Applied to ultracapacitor in practice, its realistic model is complicated capacitance-resistance net
Network structure, hold resistance branch roads comprising numerous, and different branch roads has respective electric capacity, resistance, the time corresponding to every branch road is normal
Number is also different.In view of the physical characteristic of ultracapacitor is sufficiently complex, distributed parameter model is applicable to ultracapacitor
It is described.In general occasion, ultracapacitor can use Simplified equivalent model, and in stored energy application research, this model is claimed
For the classical model of ultracapacitor, principle analysis and circuit simulation typically are carried out to super capacitor using the model.
Step 2：The low voltage crossing scheme based on bulky capacitor support is designed, using subsidiary engine frequency converter DC link as research pair
As being equipped with the bulky capacitor of suitable capacity in frequency converter DC side, electric capacity configuration capacity being calculated.From theory analysis,
The discharge current of bulky capacitor is bigger, and its terminal voltage just declines faster.So when frequency converter institute bringing onto load is bigger, to maintain one
Fixed latter stage DC voltage then needs to be connected in parallel on the super electricity of DC link to ensure that frequency converter is not shut down because of under-voltage and excessively stream
Hold also bigger.
The capacity of monomer super capacitor and quantity in parallel and total capacity and serial number are that relation is as follows：
NbCf=NcCs (13)
Wherein, NbFor quantity in parallel, CsFor the total capacity of super capacitor group.
Step 3：Design energy-dissipating type high voltage crossing scheme.Frequency converter rectification output equivalent is direct voltage source and power supply etc.
Effect internal resistance r is in series, and Converting Unit can be equivalent to load resistance with motor.Have when switching S open circuits：
U-I*r=RL*I (14)
Udc=RL*I (15)
When the switch s is closed,
It can be obtained according to above formula：
In the application of reality, braking resistor power should be selected according to the mean power of braking.In braking procedure, if
Peak power during braking is that mean power is that braking time t, the high-tension generation cycle is T.According to Shi Ke get：
Mean power can be expressed as：
According to national grid voltage ride-through specification, it is 0.5s temporarily to rise time t, and high-tension generation cycle T is then needed according to reality
Border situation determines.
Step 4：According to above-mentioned raising fossil power plant auxiliary engine frequency converter specific implementation step, subsidiary engine frequency converter optimization plan is provided
Slightly.After N-1 or ground short circuit failure occur for power network, it can improve fossil power plant auxiliary engine high-low voltage using the strategy and pass through energy
Power 5%, greatly improve power network safety operation level.
A kind of technical method for the high-low voltage ride-through capability for improving fossil power plant auxiliary engine frequency converter of disclosure of the invention, category
High voltage crossing and low voltage ride-through capability testing field in high-power electric and electronic technology, solve fiery under failure mode
Group of motors subsidiary engine high-low voltage crossing problem.This method includes：Establish bulky capacitor mathematical modeling；According to power plant's actual parameter, with
It is goal condition to improve fossil power plant auxiliary engine frequency converter low voltage ride-through capability, formulates the corresponding low electricity based on bulky capacitor support
Press crossing technology scheme；To improve fossil power plant auxiliary engine frequency converter high voltage crossing ability as goal condition, it is high to formulate energy-dissipating type
Voltage ride-through scheme.This method is provided optimal using improving fossil power plant auxiliary engine high and low pressure fault ride-through capacity as final goal
Technological invention scheme, the safe and stable operation for improving thermal power plant and power network are horizontal.
Low voltage crossing scheme proposed by the present invention based on bulky capacitor support, control loop is simple, response is rapid, in electricity
When pressure is fallen, frequency converter stable operation is securely maintained；Energy-dissipating type high voltage crossing technical scheme proposed by the present invention is in frequency conversion
The configuration of device DC link is high-power to unload energy copped wave resistance, when frequency converter primary voltage is normal, unloads energy resistance and is in bypass condition,
When the elevated setting value of voltage, energy resistance input is unloaded, frequency changer direct current bus voltage can be reduced to the pressure that frequency converter can be run
Value, during the rise of collateral security voltage, frequency converter not chaser.The technology is equally applied in large power plant.Both schemes
Being greatly enhanced the technical method of fossil power plant auxiliary engine frequency converter high and low pressure ride-through capability, can to fully meet national grid targeted
The associated specifications that subsidiary engine frequency converter proposes.
Claims (4)
- A kind of 1. method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability, it is characterised in that：1), low-voltage ride-through method：In electric power incoming line Voltage Drop, pass through inverter of the low-voltage crossing electric capacity into frequency converter Dc source support is provided, is specially：Low-voltage crossing electric capacity is equipped with frequency converter DC side, the terminal voltage of its low-voltage crossing electric capacity is less than frequency converter DC voltage Value, series opposing diode between frequency converter DC side and low-voltage crossing electric capacity；When fossil power plant auxiliary engine frequency converter primary voltage When value declines, low-voltage crossing electric capacity provides DC energy using fly-wheel diode as passage, to inverter, makes frequency converter certain Stable operation is kept in time；2), high voltage crossing method：When frequency converter inlet wire alternating voltage is rapidly increased to the rated voltage level above, with power consumption The mode of copped wave limits voltage, is specially：Detection circuit is provided with power network bus, braking resistor R is in parallel with load Rl, and Braking resistor R access and disengaging is controlled by electronic switch S；When the detection electric circuit inspection on bus hinders for some reason to line voltage And during moment rise, electronic switch S closures, make braking resistor R access operations；When line voltage is normal, electronic switch S breaks Open, make braking resistor R out of service.
- A kind of 2. 1 method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability as requested, it is characterised in that： It is described 1) in, the highest terminal voltage value of low-voltage crossing electric capacity should be less than the rated value of frequency converter DC side busbar voltage.
- A kind of 3. 1 method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability as requested, it is characterised in that： It is described 1) in, low-voltage crossing capacitance most 0-100 μ f；It is former that low-voltage crossing electric capacity under the conditions of this is considered as linear energy storage Part, the terminal voltage of its electric capacity and discharge time are into linear dependence.
- A kind of 4. 1 method for improving fossil power plant auxiliary engine frequency converter high-low pressure ride-through capability as requested, it is characterised in that： It is described 2) in, DC voltage that detection circuit is had a try on detection bus, and determine DC voltage with frequency converter heat and relatively reach poor Value, by PI controllers, IGBT dutycycle in control electronic switch S, so as to control control electronic switch S on off operating mode.
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| CN112003257A (en) * | 2020-07-29 | 2020-11-27 | 许继集团有限公司 | Control system and method for preventing direct current energy consumption device from being refused |
| US11677345B2 (en) | 2019-12-13 | 2023-06-13 | Xinjiang Goldwind Science & Technology Co., Ltd. | Control method and system for continuous high and low voltage ride through of permanent-magnet direct-drive wind-driven generator set |
| US11817712B2 (en) | 2019-12-13 | 2023-11-14 | Xinjiang Goldwind Science & Technology Co., Ltd. | High-low voltage continuous ride-through control method and system for permanent magnet direct-drive wind power generating set |
-
2017
- 2017-12-08 CN CN201711312264.0A patent/CN107846042A/en not_active Withdrawn
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2020047098A1 (en) * | 2018-08-30 | 2020-03-05 | General Electric Company | Trip reduction tool for a wind turbine power system |
| CN110635672A (en) * | 2019-09-27 | 2019-12-31 | 杭州电子科技大学 | Frequency converter high voltage ride through method based on direct current side voltage division |
| US11677345B2 (en) | 2019-12-13 | 2023-06-13 | Xinjiang Goldwind Science & Technology Co., Ltd. | Control method and system for continuous high and low voltage ride through of permanent-magnet direct-drive wind-driven generator set |
| US11817712B2 (en) | 2019-12-13 | 2023-11-14 | Xinjiang Goldwind Science & Technology Co., Ltd. | High-low voltage continuous ride-through control method and system for permanent magnet direct-drive wind power generating set |
| CN112003257A (en) * | 2020-07-29 | 2020-11-27 | 许继集团有限公司 | Control system and method for preventing direct current energy consumption device from being refused |
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