CN207625288U - A kind of fault disconnection device accessing multiple regional powers suitable for double-bus - Google Patents

Abstract

The utility model discloses a fault resolution device suitable for double busbars connected to power supplies in multiple regions, which includes an AC volume acquisition plug-in, a power supply/switch value input plug-in, a CPU plug-in, a switch value output plug-in, and an expansion plug-in; the fault solution The serial device is connected to the three-phase voltage and the open triangle zero-sequence voltage of the two sets of buses, and the isolation knife switch position of the bus connected to the power supply in each region is configured with multiple rounds of exits; to realize a fault-disconnecting device to meet the requirements of double-bus access to all Disaggregated demand for regional power and unaffected by changes in operating mode.

Description

A fault de-loading device suitable for double busbars connected to power supplies in multiple regions

technical field

The utility model belongs to the technical field of power system safety, and in particular relates to a fault unloading device suitable for double busbars connected to power supplies in multiple regions.

Background technique

The grid-connection of regional power sources has changed the traditional structure of single-source radial power supply in terminal stations, and has had an impact on traditional relay protection reclosing, standby automatic switching, and overcurrent protection coordination of each section. After the fault is removed, if the grid-connected power supply runs in an isolated island with load, the quality of power supply will be unreliable, which may damage the electrical equipment and endanger the personal safety of maintenance personnel. Therefore, in the grid-connected occasions of wind power, photovoltaic and other regional power sources, it is required to configure a fault disconnection device to ensure that the grid-connected regional power source is cut off when the grid fails. Conventional fault de-loading devices only connect to a group of bus three-phase voltage and external open triangle zero-sequence voltage. Over-frequency de-coupling protection, zero-sequence over-voltage de-coupling protection to jump off the network switch of the regional power supply.

The northwestern region of my country is rich in wind and solar resources, and the capacity of new energy generation is huge. The regional power supply often adopts the method of centralized grid connection with 110kV voltage level buses. The 110kV side of the 330kV or 220kV substation is mostly connected by double busbars. The grid-connected connection lines of the regional power sources may be located on different buses, and the location of the busbars connected to the regional power sources will change with the change of the operation mode. In the initial stage of substation operation, when only one region’s power supply is connected to the grid, a conventional fault disassembly device can meet the disassembly requirements, but because the conventional fault disassembly device has only one set of bus voltage access capabilities, the external circuit needs Voltage switching is performed according to the location of the busbar connected to the regional power supply. After the expansion of the later project, as the new regional power is connected to the grid, it is located on a different bus from the grid-connected regional power. The conventional fault decommissioning device cannot meet the decommissioning requirements of dual busbars connected to multiple regional power sources. The traditional solution is to add another conventional fault-disconnecting device, and design the circuit for the newly added conventional fault-disconnecting device, including the transformation of sampling circuit, open-in circuit, open-out circuit, and voltage switching circuit.

The problem with the traditional solution is that in the case where the double busbars are connected to multiple regional power sources, the conventional fault-disconnecting device is configured according to the regional power sources instead of busbar configurations. Every time a new regional power source is connected to the grid, it is necessary to add another one. There are only one conventional fault-disconnecting device, which has problems such as low utilization rate of the protection device, heavy workload of design circuit transformation, and unfavorable expansion in the later stage. The newly-added delisting protection screen cabinet will occupy the reserved screen space of the secondary design room. Generally, the reserved screen space of the secondary design room is limited, and the conventional fault delisting device cannot meet the grid connection of more regional power supplies in the later period.

In the initial stage of substation construction, if there is no regional power grid connection plan, or when only one regional power grid is considered, it is generally not equipped with a conventional fault-disconnecting device for each of the dual busbars. Even if a conventional fault-disconnecting device is configured for each busbar in the initial design, on the one hand, when only one region’s power supply is connected to the grid in the initial stage, only one protection device is effectively put into operation, and the other protection device is vacant; on the other hand, considering the operation After the method is adjusted, the position of the busbar connected to the regional power supply will change, and the conventional fault release device cannot automatically adapt to the change of the operation mode. Grid-connected, the workload of export adjustment has doubled, which is not conducive to operation and maintenance work, and is also not conducive to the grid-connected operation of regional power sources.

Utility model content

The purpose of this utility model is to provide a new type of fault unloading device for the situation where double busbars are connected to multiple regional power supplies. Only one faulty unloading device is configured to meet the requirements for unloading of all regional power supplies connected by double busbars demand, and can adapt to changes in operation mode, and is not affected by changes in the location of the busbar connected to the regional power supply, without manual intervention. In view of the situation that more regional power sources are connected to the grid in the later project expansion, there is no need to add new protective screen cabinets, and the external design only needs to make small changes to the input and output circuits of the fault de-loading device for the newly added regional power sources. There is no need to add a fault-disconnecting device, which improves the utilization rate of the protection device, reduces operation and maintenance, and ensures the economic benefits of regional power grid connection.

In order to achieve the above object, the solution of the present utility model is:

A fault decoupling device suitable for double busbars connected to power supplies in multiple regions. It is applied to the decoupling occasions when double buses are connected to power supplies in multiple regions. Volume output plug-in, expansion plug-in; Among them, the power supply/switch input plug-in is used to supply power to the fault de-loading device on the one hand, and on the other hand to collect the signal input required by the fault de-loading device; the AC volume acquisition plug-in collects three The phase voltage and open triangle zero-sequence voltage are converted into digital signals and transmitted to the CPU plug-in; the CPU plug-in receives the digital signal sent by the AC volume acquisition plug-in, performs analog calculation, and receives the signal input sent by the power supply/switch input plug-in, And use these analog quantity status and signal input to judge the double-bus de-loading protection; the switch value output plug-in converts the de-loading command sent by the CPU plug-in into the output of the relay outlet; the expansion plug-in is used to expand the signal input of the faulty de-loading device and export output.

Further, the AC volume acquisition plug-in is configured with 8 voltage channels, of which 6 voltage channels are set according to the secondary rated value of the bus PT of 100V, and are used to connect two sets of bus three-phase voltages; the other 2 voltage channels are set according to the zero-sequence PT The secondary rated value is set to 300V, which is used to connect the external open triangle zero-sequence voltage of two sets of busbars.

Further, the CPU plug-in is configured with dual decoupling protection, and performs analog calculations for the connected two sets of bus voltages, and respectively performs low voltage decoupling protection, low frequency decoupling protection, overvoltage decoupling protection, and overfrequency decoupling protection , The logical judgment of the zero-sequence overvoltage de-sequence protection, the de-sequence protection logic of the two groups of busbars operates independently and does not affect each other.

Further, the power/digital input plug-in is used to connect to the isolation switch position of the bus bar of the power supply in each area. The CPU plug-in performs self-identification of the grid-connected state of the regional power supply through the position of the isolated knife switch connected, and establishes a mapping relationship between the regional power supply unloading outlet and the double busbar unloading protection action; specifically: the CPU plug-in judges the position of the isolating knife switch Open and close state, automatically identify whether the regional power supply is located at I bus or II bus, and judge whether the disconnection outlet contact of the regional power supply is closed after the I bus disconnect protection action, or is closed after the II bus disconnect protection action, when a certain When the position of the bus isolation switch of the power supply in a region is all in the position, it is judged that the power supply in the region is not connected to the grid, and the disconnection outlet of the power supply in the region is not closed.

Further, the switch value output plug-in is configured with multiple rounds of regional power supply decommissioning outlets, and an expansion plug-in is provided. Specifically: the switching value output plug-in is configured with multiple decoupling ports, the expansion plug-in is flexibly configured, the number of signal inputs and output outputs of the fault decoupling protection device can be expanded, and the power supply of multiple regions is connected to the double busbar, as well as the expansion of the later project. In the case of regional power grid connection, in terms of external circuit design, it is only necessary to change the opening and closing circuit of the isolation switch position of the busbar and the opening and exiting circuit of the delisting outlet for the newly added regional power supply, which can meet the needs of the newly added regional power supply and There is no need to add a fault disconnecting device for the disconnection requirements after the grid, and it has no impact on the power supply of the areas that have been connected to the grid.

After adopting said scheme, the beneficial effects of the utility model are:

1) A fault de-serialization device realizes the de-serialization function of the power supply in all areas connected to the double busbar, which significantly improves the utilization rate of the protection device and saves the reserved screen space in the secondary design room;

2) Automatically identify the grid-connected status of the regional power supply, and will not be affected by changes in the operation mode, reducing operation and maintenance;

3) Adaptive to the decoupling requirements of more regional power grids after the expansion of later projects, no need to add fault decoupling devices, and small changes in the design circuit, which is convenient for more regional power grids.

Description of drawings

Fig. 1 is the plug-in configuration diagram of the failure disassembly device of the present utility model;

Figure 2 is a typical wiring diagram of the dual busbars connected to the power supply in two regions in the power supply system.

Detailed ways

The technical solutions of the present utility model will be described in detail below in conjunction with the accompanying drawings.

The utility model provides a fault unloading device suitable for double busbars connected to power supplies in multiple regions. Power/digital input plug-in, CPU plug-in, AC acquisition plug-in, digital output plug-in, expansion plug-in.

The power supply/switch input plug-in plug-in of the fault de-sequencing device of the utility model is used to supply power to the fault de-sequencing device on the one hand, and on the other hand to collect the signal input required by the fault de-sequencing device, including the isolation knife of the busbar of the power supply in each area Gate position signal; the AC volume acquisition plug-in of the fault unloading device of the present utility model is connected to the external opening triangle zero-sequence voltage of two sets of busbars, and converts the collected two sets of busbar voltage analog signals into digital signals, and transmits them to the CPU plug-in ; The switching value output plug-in of the fault de-sequencing device of the present utility model converts the de-sequencing command transmitted by the CPU plug-in into the output of the relay outlet.

Referring to Figure 2, it is wiring for a typical 110kV double busbar connected to power supplies in multiple regions. The schematic diagram shows the main wiring of a 330kV substation. The medium-voltage side of the transformer is in the form of 110kV double-busbar wiring. There are two regional power sources connected to the grid. The three-phase voltages of the 110kV I bus are represented as Ua1, Ub1, and Uc1 in sequence, and the external open triangle zero sequence of the 110kV I bus The voltage is expressed as U01; the three-phase voltage of the 110kVII bus is expressed as Ua2, Ub2, Uc2 in turn, and the external open triangle zero-sequence voltage of the 110kVII bus is expressed as U02. Figure 2 is just an example, showing the case where the medium voltage side of the 330kV substation has 110kV dual buses connected to power sources in multiple regions, and other cases such as the case where the 110kV dual buses of a 220kV substation are connected to power sources in multiple regions, or double buses of other voltage levels The situation is similar for accessing multiple regional power sources.

Aiming at the typical wiring of double busbars connected to two regional power sources in the power supply system in Figure 2, the AC volume acquisition plug-in of the fault unloading device of the utility model is connected to two sets of busbar three-phase voltages Ua1, Ub1, Uc1, Ua2, Ub2, Uc2 , and 2 external open triangle zero-sequence voltages U01, U02; the power supply/switch value input plug-in plug-in of the fault unloading device of the present utility model is connected to the I mother and II mother isolation switch positions of the regional power supply 1 and the regional power supply 2; The output output plug-in of the fault release device of the utility model is respectively configured with release output contacts for the regional power source 1 and the regional power source 2 .

The CPU plug-in of the fault release device of the present utility model receives the digital signal transmitted by the AC volume acquisition plug-in, performs analog calculation, uses these analog signals to carry out double release protection judgment, and calculates the real-time value of each group of busbars in each interruption. In terms of voltage and frequency, logical judgments including low frequency, low voltage, overfrequency, overvoltage and zero sequence overvoltage are carried out. The decoupling protection logic of the two groups of busbars operates independently and does not affect each other. When the voltage or frequency of any group of busbars satisfies the protection logic, only the de-loading command of this group of busbars will be issued. For example, if the voltage of bus I is abnormal and satisfies the low-voltage logic, and the voltage and frequency of bus II are normal, then the fault release device of the present utility model only sends the low-voltage unloading action signal of bus I.

The CPU plug-in of the fault decoupling device of the utility model performs self-identification of the grid-connected state of the regional power supply through the position of the connected isolation knife switch, establishes the mapping relationship between the decoupling port of the regional power supply and the decoupling protection action of the double busbar, and decoupling according to the busbar The protection action signal sends a decommissioning command to the regional power supply connected to the abnormal bus.

For the wiring in Figure 2, name the position of the isolation switch I of the regional power source 1 as 11, the position of the isolation switch II of the regional power source 1 as 12; the position of the isolation switch I of the regional power source 2 as 21, and the position of the isolation switch of the regional power source The position of the Ⅱ bus isolation switch of 2 is named 22 (the first number indicates the power supply of the region: 1 indicates the area power supply 1, 2 indicates the area power supply 2; the second number indicates the position of the access bus: 1 indicates the access to the I bus, 2 indicates access to bus II); the mapping relationship between the de-separation port and the dual de-sequence protection when the power supply in the two regions is located on different buses in each operation mode is shown in the following table:

Table 1 Mapping relationship between regional power supply unloading outlets and double unloading protection

The switching value output plug-in of the fault unloading device of the utility model is equipped with multiple rounds of regional power unloading outlets. For the later expansion of the new regional power supply grid connection, only the power supply/switching input plug-in of the fault unloading device needs to be increased. The location of the isolation knife switch of the busbar of the newly added regional power supply, and the switch value output plug-in allocation of the delisting interface contacts of the newly added regional power supply can meet the delisting requirements after the newly added regional power supply. For the typical wiring in Figure 2, for example, the grid connection of the power supply in the newly added area, the isolation switch position of the bus bar of the newly added area power supply is defined as the opening of the power supply 3Ⅰ bus isolation switch and the opening of the power supply 3Ⅱ bus isolation switch, and the switching value Any unused contact of the output plug-in is defined as the unloading port of the newly added regional power supply, which can realize the unloading function of the newly added regional power supply after being connected to the grid. When the power/digital input plug-in or digital output plug-in has no spare contacts, the fault release device can expand the signal input and output output by configuring the expansion plug-in to meet the de-serialization requirements after the new regional power supply. The external circuit only involves Simple switch-in and switch-out adjustments facilitate the grid-connected access of power sources in more areas in the later stage, and have no impact on the power sources in areas that have already been connected to the grid.

To sum up, the fault release device of the present utility model can be realized in the occasion where the double busbars are connected to multiple regional power sources. When the power supply system fails, the disconnection function of the connected regional power sources will not be changed by the system operation mode No need for manual intervention, the decoupling protection adapts to the decoupling requirements after the power supply in the newly added area is connected to the grid, the hardware is configured with multiple rounds of outlets, and the expansion is flexible. The de-loading function of all regional power supplies entered.

The above examples are only to illustrate the technical ideas of the present utility model, and cannot limit the scope of protection of the present utility model. Any changes made on the basis of the technical solutions according to the technical ideas proposed by the utility model all fall into the scope of the utility model. within the scope of protection.

Claims (5)

1. a kind of fault disconnection device accessing multiple regional powers suitable for double-bus, it is characterised in that：Including power supply/switch Amount input plug-in unit, CPU card, of ac acquisition plug-in unit, output switch parameter plug-in unit, expansion plugin；Wherein：

Power supply/On-off signal plug-in unit：On the one hand for powering to fault disconnection device, fault disconnection device is on the other hand acquired Required signal input；

Of ac acquires plug-in unit：The three-phase voltage and open delta residual voltage for acquiring two groups of busbares, are converted to digital signal, pass It is defeated by CPU card；

CPU card：The digital signal that of ac acquisition plug-in unit is sent is received, analog quantity calculating is carried out, receives power supply/switch The signal input that amount input plug-in unit is sent, and carry out sentencing for bilingual row protection using these analog quantity states and signal input It is disconnected；

Output switch parameter plug-in unit：The off-the-line order that CPU card is sent is converted into relay outlet output；Expansion plugin： Signal for extending fault disconnection device inputs and outlet output.

2. a kind of fault disconnection device accessing multiple regional powers suitable for double-bus as described in claim 1, feature It is：The of ac acquisition plug-in unit includes 8 road voltage channel configurations, wherein 6 road voltage channels press bis- rated values of busbar PT 100V is arranged, the three-phase voltage for accessing two groups of busbares；Other 2 road voltage channel is set by bis- rated value 300V of zero sequence PT It sets, the external open delta residual voltage for accessing two groups of busbares.

3. a kind of fault disconnection device accessing multiple regional powers suitable for double-bus as described in claim 1, feature It is：The CPU card configures bilingual row protection, carries out protecting comprising low pressure off-the-line respectively for two groups of busbar voltages of access Shield, the protection of low frequency off-the-line, over-pressed off-the-line is protected, overfrequency off-the-line is protected, the logic judgment of zero sequence overvoltage off-the-line protection, two groups of busbares Off-the-line relay protective scheme independent operating, be independent of each other each other.

4. a kind of fault disconnection device accessing multiple regional powers suitable for double-bus, feature exist as described in claim 1 In：The power supply/On-off signal plug-in unit accesses the isolation switch position of the busbar of each regional power, and the CPU card is logical Cross access isolation switch position carry out regional power and net state self-identifying, establish regional power off-the-line outlet and double-bus The mapping relations of off-the-line protection act.

5. a kind of fault disconnection device accessing multiple regional powers suitable for double-bus, feature exist as described in claim 1 In：The output switch parameter plug-in card configuration takes turns the outlet of regional power off-the-line more, and provides expansion plugin.