CN211018281U - Static reactive power compensation device - Google Patents

Abstract

The utility model discloses a static reactive power compensator, include: the compensation switching action element is used for acquiring the voltage and the current of the power grid in real time, and based on the voltage and the current, when the current reactive compensator cannot provide all capacitive reactive power required by the power grid system, a TSC switching instruction is generated; the reactive compensator is connected in parallel with the power grid transmission line and compensates first reactive power which is consistent with reactive capacity required by the system in normal operation; and the TSC branch circuit is connected in parallel with the current transmission line, and controls the TSC branch circuit to be put into the transmission line after receiving the TSC input instruction so as to compensate the reactive power of the power grid system except the first reactive power required by the abnormal condition that the capacitive reactive power demand is increased. The utility model discloses reduce reactive power compensator's unnecessary loss, still effectual suppression bus voltage reduces on this basis to stable system power factor.

Description

Static reactive power compensation device

Technical Field

The utility model belongs to the technical field of the reactive compensation technique and specifically relates to a static reactive power compensator of mixed type is related to.

Background

The Static Var Compensator (SVC) has the advantages of simple structure, mature technology, low relative cost and the like, is the first choice for users to perform reactive compensation at present, and is widely applied to occasions such as transmission and distribution networks, large-scale factories, steel enterprises and the like.

The SVC generally consists of a filter compensation branch FC and a thyristor controlled reactor TCR branch. The capacity of the FC leg has two uses: one part is used for compensating the reactive power of the system and improving the power factor; the other part is used for balancing reactor hysteresis reactive power and stabilizing the bus voltage when the bus voltage fluctuates. However, in order to filter out higher harmonics in the electrical energy transmitted by the grid, all of the FC branches must be put into operation. At this time, the capacitive reactive power of the FC compensation exceeds the capacitive reactive power required in the system to generate an excessive capacitive reactive power. Therefore, the TCR branch needs to be put into use to balance the capacitive reactive power which is over-compensated currently, and since the FC branch and the TCR branch both work in a state of large current, unnecessary loss is generated in both the current branches (for example, the multi-stage FC branch generates a large amount of redundant capacitive reactive power, and the TCR branch needs to generate inductive reactive power with corresponding capacity to balance due to the generation of the large amount of redundant capacitive reactive power).

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a static var compensator, include: the compensation switching action element is used for acquiring the voltage and the current of the power grid in real time, and based on the voltage and the current, when the current reactive compensator cannot provide all capacitive reactive power required by the power grid system, a TSC input instruction is generated; the reactive compensator is connected in parallel with the power grid transmission line and compensates first reactive power which is consistent with reactive capacity required by the system in normal operation; and the TSC branch circuit is connected in parallel with the transmission line, and controls the TSC branch circuit to be input into the transmission line after receiving the TSC input instruction so as to compensate the reactive power of the power grid system except the first reactive power required by the abnormal condition that the capacitive reactive power demand is increased.

Preferably, the reactive power compensator includes: an FC branch connected in parallel to the transmission line and providing the first reactive power; and the TCR branch circuit is connected in parallel with the transmission line, receives a TCR input instruction containing current TCR thyristor conduction angle information, and outputs inductive power conforming to the current TCR thyristor conduction angle under the control of the instruction so as to balance redundant capacitive reactive power of a system corresponding to the condition that the capacitive reactive power provided by the reactive power compensation device exceeds all the capacitive reactive power when the TSC branch circuit is input or not input.

Preferably, the TCR arms comprise: a TCR current collection unit, the first end of which is connected with the transmission line; and the TCR power output unit adopts a triangular connection structure taking a first structure as a side and is connected with the second end of the TCR current acquisition unit in a three-phase triangular connection mode, wherein the first structure is a series connection structure of a thyristor device and a reactor.

Preferably, the first structure includes: the phase control circuit comprises a thyristor, and a first phase control reactor and a second phase control reactor which are respectively arranged at two ends of the thyristor.

Preferably, an inlet end of the FC branch is connected to the transmission line, wherein the FC branch includes an FC current collection unit, an FC reactor, and an FC compensation capacitor bank, which are sequentially connected from the inlet end.

Preferably, the reactive power compensator further comprises a preset number of the FC legs.

Preferably, the incoming line end of the TSC branch is connected with the transmission line, wherein the TSC branch comprises a TSC current acquisition unit, a TSC compensation capacitor bank, a TSC current-limiting reactor and a TSC power output unit which are sequentially connected from the incoming line end, the TSC power output unit is integrated in the anti-parallel thyristor, and the tail end of the TSC power output unit adopts a three-phase star-shaped connection mode.

Preferably, the device further comprises a protection module disposed in each branch, wherein the protection module comprises a disconnector unit and an arrester.

Preferably, the compensation switching action element detects whether a grid voltage drop phenomenon occurs currently or whether a phenomenon that the grid voltage continuously exceeds a preset grid safe operation voltage threshold value within a preset time threshold value occurs according to the grid voltage and the grid current, and determines whether the TSC branch circuit needs to be switched in according to a detection result, wherein when the TSC branch circuit does not need to be switched in, a corresponding TSC exiting instruction is generated, so that the TSC branch circuit exits from the transmission line under the control of the TSC exiting instruction.

Preferably, the compensation switching action element is further configured to, when it is determined that the TSC branch needs to be switched, acquire a current at an incoming line end of each branch in the device in real time, calculate redundant capacitive reactive power of the system according to the current of each branch, the grid voltage, and the grid current, and obtain the current TCR thyristor conduction angle.

Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:

the utility model discloses a static var compensator, its purpose is with in the static var compensator FC branch road some capacity allocation for TSC branch road that is used for stabilizing voltage for the FC branch road only needs to provide the required idle work of compensation power factor (required idle work when electric wire netting system normal operating promptly) at normal during operation, reduces the loss of reactive compensator SVC at normal during operation. Thus, the bus voltage can be stabilized and the capacity of the reactive power compensator can be improved while reducing the SVC loss. The utility model is suitable for a load consumer is more, and the great occasion of individual equipment capacity, can arouse bus voltage to reduce by a wide margin when owing to start for the reactive demand volume of the current capacitive of grid system increases suddenly. Therefore, to this kind of condition, the utility model discloses a reactive power compensator has better outstanding compensation effect, not only can reduce the loss of unnecessary power in TC branch road and the TCR branch road in the device, can also be on this basis effectual suppression system capacity reactive demand increases suddenly, and the fluctuation of the system power factor who brings stabilizes busbar voltage and system power factor.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, together with the description of embodiments of the invention, serve to explain the invention and not to limit the invention. In the drawings:

fig. 1 is an overall configuration diagram of a static var compensator according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of a static var compensator according to an embodiment of the present application.

Detailed Description

The following detailed description will be made with reference to the accompanying drawings and examples, so as to solve the technical problems by applying technical means to the present invention, and to fully understand and implement the technical effects of the present invention. It should be noted that, as long as no conflict is formed, the embodiments and the features in the embodiments of the present invention may be combined with each other, and the technical solutions formed are all within the scope of the present invention.

The Static Var Compensator (SVC) has the advantages of simple structure, mature technology, low relative cost and the like, is the first choice for users to perform reactive compensation at present, and is widely applied to occasions such as transmission and distribution networks, large-scale factories, steel enterprises and the like.

The static var compensator SVC generally comprises a filter compensation branch FC and a thyristor controlled reactor TCR branch. The capacity of the FC leg has two uses: one part is used for compensating the reactive power of the system and improving the power factor; the other part is used for balancing reactor hysteresis reactive power and stabilizing the bus voltage when the bus voltage fluctuates. However, in order to filter out higher harmonics in the electrical energy transmitted by the grid, all of the FC branches must be put into operation. At this time, the capacitive reactive power of the FC compensation exceeds the capacitive reactive power required in the system to generate an excessive capacitive reactive power. Therefore, the TCR branch needs to be put into use to balance the capacitive reactive power which is over-compensated currently, and since the FC branch and the TCR branch both work in a state of large current, unnecessary loss is generated in both the current branches (for example, the multi-stage FC branch generates a large amount of redundant capacitive reactive power, and the TCR branch needs to generate inductive reactive power with corresponding capacity to balance due to the generation of the large amount of redundant capacitive reactive power).

In order to solve the technical problem, the embodiment of the utility model provides a reactive power compensator of mixed type is proposed. The device distributes a part of capacity used for stabilizing voltage in an FC branch circuit in the SVC to the TSC branch circuit, so that the FC branch circuit only needs to provide reactive power required by compensation power factor under normal operation of a power grid system during normal operation, and loss corresponding to redundant capacitive reactive power of the system generated during normal operation of the SVC is reduced. Further, when the power grid voltage of a power grid transmission line bus falls, the TSC branch is controlled to be put into the current transmission line, so that the TSC branch (replacing the second part of capacity loss in the original FC branch) compensates a large amount of capacitive reactive power requirements generated when the power grid voltage of a power grid system falls, and the bus voltage is stabilized. Therefore, the utility model discloses a mode that the TSC branch road was allocated with some in the whole reactive power of the required compensation of system when the abnormal operation appears has reduced the unnecessary loss of FC branch road, further reaches the purpose that improves reactive power compensator's capacity.

Before explaining the structure of the reactive power compensation device of the present invention, it is necessary to explain the situation to which the device is adapted. The utility model provides a mixed type reactive power compensator is applied to the great condition of electric wire netting distribution system load consumer more, and single load equipment capacity, can arouse the occasion that busbar voltage reduces by a wide margin when starting to the great load equipment of capacity, at this moment, can make electric wire netting system can take place the trouble condition that the net pressure falls or the sensitive load increases suddenly in the electric wire netting load (also be exactly the abnormal operation stage of electric wire netting system). Accordingly, when such an abnormality occurs, the capacitive reactive power demand of the grid system may suddenly increase, and the current reactive power compensation device is required to compensate a larger capacity of reactive power to the grid system. To this kind of condition, the utility model discloses a technical scheme who drops into the TSC branch road utilizes the idle in the required compensation of TSC branch road compensation increase part, keep reactive power compensator only provide when electric wire netting system normal operating required reactive capacity can to reach the mesh that reduces the unnecessary loss of FC branch road. Therefore, the utility model discloses on reducing the basis that reactive power compensator produced unnecessary loss, can effectual suppression bus voltage reduce or the reactive condition of the reactive demand sudden increase of system capacity, stable system power factor and bus voltage.

Fig. 1 is an overall configuration diagram of a static var compensator according to an embodiment of the present application. As shown in fig. 1, the reactive power compensation device of the present invention at least includes: compensation switching action element 100, reactive compensator 200 and TSC branch 300. The reactive compensator 200 is a static reactive compensator, and is connected in parallel to a bus of a power grid transmission line. The TSC branch 300 is also connected in parallel in the grid transmission line busbar. Further, the compensation switching action element 100 is used for acquiring the voltage and current of the power grid in real time, and based on the situation, when it is determined that the current reactive compensator cannot provide all capacitive reactive power required by the power grid system, a TSC switching instruction is generated; the reactive compensator 200 is used for compensating first reactive power which is consistent with reactive capacity required by the normal operation of the power grid system; the TSC branch 300 is configured to control the TSC branch to be put into the current power grid transmission line bus after receiving the TSC putting instruction sent by the compensation putting and withdrawing action element 100, so as to compensate for reactive power except the first reactive power corresponding to the situation that the capacitive reactive power demand generated by the power grid system in abnormal operation is increased.

Fig. 2 is a schematic structural diagram of a static var compensator according to an embodiment of the present application. The specific structure and function of the static var compensator according to the present invention will be described in detail with reference to fig. 1 and 2.

In the embodiment of the present invention, the compensation switching element 100 can select a single chip or a programmable logic chip, and bear the program content related to the reactive compensation control part. In a specific implementation process, the component 100 requiring compensation for switching on and off acquires, in real time, the grid voltage (before compensation) output by the end of the grid power distribution system through the grid voltage acquisition unit TV, acquires, in real time, the grid current (before compensation) output by the end of the grid power distribution system through the grid current acquisition unit TA, and determines, according to the acquired grid voltage and grid current information, that the current reactive compensator cannot provide all the capacitive reactive power required by the grid system, that is, determines whether the current grid system is operating in a normal state. If the state is a normal state, all capacitive reactive power currently needed is provided to the power grid system only by using the reactive power compensator 200; if the abnormal state exists, all capacitive reactive power needed currently is provided to the grid system only under the combined action of the reactive power compensator 200 and the TSC branch 300, and at this time, all capacitive reactive power needed by the grid system is not needed to be provided by the current reactive power compensator 200.

Specifically, the compensation switching element 100 is configured to detect whether a grid voltage drop phenomenon occurs currently or whether a phenomenon that the grid voltage continuously exceeds a preset grid safe operation voltage threshold within a preset time threshold occurs currently according to the grid voltage and the grid current, and determine whether the TSC branch 300 needs to be switched into the current grid transmission line according to a detection result. If the two phenomena do not occur, determining that the current power grid system is in a normal operation state, without inputting the TSC branch circuit 300, immediately generating a corresponding TSC exit instruction, and sending the current TSC exit instruction to the current TSC branch circuit 300, so that the current TSC branch circuit 300 exits from the transmission line under the control of the TSC exit instruction. At this time, the TSC power output unit T1 in the TSC branch 300 controls itself to be in the off state under the control of the TSC exit instruction, and does not need to provide corresponding capacitive power to the current grid transmission line.

Further, reactive power compensator is at normal operating, at first, compensation throw action component 100 is according to grid voltage, grid current, FC branch current and TCR branch current, calculates the first reactive power that the actual needs compensated to the electric wire netting system (make electric wire netting system after actually exporting corresponding reactive power to electric wire netting load, process the utility model discloses a behind the voltage control compensation effect of reactive power compensator's first reactive power, provide the electric power energy that has high-efficient power factor to electric wire netting load), the corresponding current system unnecessary capacitive idle under the electric wire netting system normal operating condition and be used for balancing the current TCR thyristor conduction angle that this unnecessary capacitive power's inductive power corresponds.

In the embodiment of the present invention, in order to achieve the effect of reducing unnecessary loss of the FC branch, the reactive compensation capacity of the FC branch in the reactive compensator 200 is only required to provide the similar capacity corresponding to the first reactive power required for compensation of the grid system under the normal operation condition, at this time, the TSC branch need not to be dropped into, and the TCR branch in the reactive compensator 200 only needs to provide a small amount of inductive reactive power to balance the redundant capacitive reactive power in the system. Therefore, in this case, the current TCR thyristor conduction angle calculated by the compensation commissioning element 100 is such that the TCR branch outputs only a small amount of inductive reactive power to balance the redundant capacitive reactive power of the grid system.

In addition, if any one or two of the above phenomena occur, it is determined that the current power grid system is in an abnormal operation state, the TSC branch 300 needs to be put into, a corresponding TSC putting instruction is immediately generated, and the current TSC putting instruction is sent to the current TSC branch 300, so that the current TSC branch 300 is put into a transmission line under the control of the TSC putting instruction. At this time, the TSC power output unit T1 in the TSC branch 300 controls itself to be in a conducting state under the control of the TSC input command, and can provide corresponding capacitive power to the current power grid transmission line.

Further, when the reactive power compensation device is in abnormal operation, at first, the compensation switching action element 100 calculates the first reactive power that actually needs to be compensated to the grid system according to the grid voltage, the grid current, the FC branch current, the TCR branch current and the TSC branch current (after the grid system actually outputs corresponding reactive power to the grid load, the utility model discloses a after the voltage regulation compensation of the first reactive power of the reactive power compensation device, the power energy with high-efficiency power factor is provided to the grid load), the corresponding current system redundant capacitive reactive power under the abnormal operation condition of the grid system, and the current TCR conduction angle that the inductive power used for balancing the redundant capacitive power corresponds.

As shown in fig. 1 and fig. 2, the reactive power compensator 200 of the present invention further includes: the FC branch 210 and the TCR branch 220, and the FC branch 210 and the TCR branch 220 are all connected in parallel in the current power grid transmission line. The FC branch 210 is used to provide the first reactive power to be compensated for in normal operation of the grid system. The TCR branch 220 is configured to receive a TCR input command including current TCR thyristor conduction angle information, and output an inductive power corresponding to the current TCR thyristor conduction angle under the control of the command, so as to balance a system redundant capacitive idle corresponding to when the capacitive idle that can be provided by the reactive power compensation device exceeds all the capacitive idle when the TSC branch 300 is input or not input.

It should be noted that in the embodiment of the present invention, all capacitive reactive power corresponding to the power factor when the grid system reaches the high-efficiency electric energy transmission is indicated, under the abnormal operation condition of the grid system, because the capacitive reactive power demand corresponding to the grid system can be suddenly increased, all capacitive reactive power when the abnormal operation is performed can be suddenly increased compared with all capacitive reactive power when the normal operation is performed. Further, under the normal operation condition, the TSC branch is not put into use, and at this time, the small amount of inductive capacity provided by the TCR branch 220 is enough to balance the small amount of capacitive capacity, in which the first reactive power currently required to be compensated provided by the FC branch 210 exceeds the full capacitive reactive power under the normal operation condition. In an abnormal operation condition, the TSC branch is put into use, and at this time, a small amount of inductive capacity provided by the TCR branch 220 is enough to balance the sum of the first reactive power currently required to be compensated provided by the FC branch 210 and the suddenly increased capacitive power provided by the TSC branch, which exceeds the capacitive capacity of the total capacitive reactive power in the abnormal operation condition. Therefore, the inductive power output by the TCR branch 220 corresponding to the two power grid operation conditions is different, so that the real-time TCR thyristor conduction angle information adjusted in real time needs to be calculated by the compensation switching element 100 to control the inductive capacity provided by the TCR branch 220.

Specifically, as shown in fig. 2, the FC branch 210 includes an FC current collecting unit TA3, an FC reactor L3, and an FC compensation capacitor bank C3., wherein an incoming line end of the FC branch 210 is connected to a power grid transmission line, an FC current collecting unit TA3, an FC reactor L3, and an FC compensation capacitor bank c3 are sequentially connected from the incoming line end of the branch, the FC current collecting unit TA3 employs a current transformer, the unit TA3 is connected to the compensation switching action element 100, collects a current (FC branch current) at the incoming line end of the current FC branch 210 in real time, and sends the current information to the compensation switching action element 100, so that the compensation switching action element 100 calculates redundant reactive power of the current system with reference to current FC branch current data.

In addition, in the embodiment of the present invention, the reactive power compensator 200 further includes a predetermined number of (more than two paths of) FC branches 210. It should be noted that the specific number of branches herein is configured according to the number of the filtered harmonic, and the equivalent inductance in the power grid system needs to be considered, so as to avoid the resonance condition between all FC branches and the power grid system.

Further, the TCR branch 220 comprises: a TCR current acquisition unit TA2 and a TCR power output unit 221. The first end of the TCR current acquisition unit TA2 is used as the incoming line end of the current TCR branch 220 and connected to the current power grid transmission line, and the TCR power output unit 221 is connected to the second end of the TCR current acquisition unit TA2 in a three-phase delta connection manner. The TCR current collecting unit TA2 adopts a current transformer, the unit TA2 is connected with the compensation switching action element 100, collects the current (TCR branch current) of the current TCR branch 220 incoming line terminal in real time and sends the current information to the compensation switching action element 100, so that the compensation switching action element 100 refers to the current TCR branch current data to calculate the redundant capacitive reactive power of the current system. More specifically, the TCR power output unit 221 adopts a triangular connection structure with a first structure as a side, where the first structure is a series connection structure of a thyristor device and a reactor. The TCR power output unit 221 receives a TCR input command sent by the compensation switching action element 100, and under the control of the current TCR input command, adjusts the on/off state of each thyristor and the on/off action timing of each thyristor in the unit 221, and outputs inductive power satisfying the current TCR thyristor conduction angle, so that the inductive reactive power can be output and used for balancing the corresponding system redundant capacitive reactive power under the current system operation condition no matter in the normal operation state or the abnormal operation state of the power grid system.

Preferably, as shown in fig. 2, the first structure at least comprises a TCR thyristor T2, a first phase-controlled reactor L21 and a second phase-controlled reactor L22, wherein the first phase-controlled reactor L21 and the second phase-controlled reactor L22 are respectively arranged at two ends of the TCR thyristor T2, more preferably, the TCR thyristor T2 is integrated with an anti-parallel thyristor.

Further, with continued reference to fig. 2, the TSC branch 300 comprises a TSC current collecting unit TA1, a TSC compensation capacitor group C1, a TSC current limiting reactor L and a TSC power output unit T1, wherein the line inlet end of the TSC branch 300 is connected to the power grid transmission line, from the line inlet end of the TSC branch, a TSC current collecting unit TA1, a TSC compensation capacitor group C1, a TSC current limiting reactor L1 and a TSC power output unit T1 are sequentially connected, a current transformer is adopted by the TSC current collecting unit TA1, the unit TA1 is connected to the compensation switching action element 100, the current (TSC branch current) of the current TSC branch 300 is collected in real time and sent to the compensation switching action element 100, so that the compensation switching action element 100 calculates the redundant reactive power of the current system by referring to the current TSC branch current data, the TSC power output unit T1 is connected in inverse parallel, one end of which is connected to the TSC current limiting reactor L, and the other end is connected in a three-phase current limiting manner.

In addition, static var compensator still including setting up the protection module in each branch road. In particular, each leg (TSC leg, TCR leg and FC leg) in the device is configured with a respective protection module. Wherein, protection module includes isolator and arrester.

In the FC branch 210, a corresponding FC isolating switch QS3 and a corresponding FC arrester fv3 are sequentially arranged between the FC current collecting unit TA3 and the FC reactor L3, wherein the FC arrester FV3 is used for protecting each electrical device in the FC branch 210 from a high transient high voltage during lightning strike and limiting the follow current time to perform overvoltage protection, and the FC isolating switch QS3 is in an off state under the control of the compensation switching action element 100 when a power grid system fault or a current FC branch 210 has an overcurrent fault, so as to isolate the electrical device in the branch from the power grid line.

In the TCR branch 220, a corresponding TCR disconnector QS2 and a TCR arrester FV2 are sequentially arranged between the TCR current collecting unit TA2 and the TCR power output unit 221. The TCR arrester FV2 is used to protect electrical equipment within the TCR leg 220 from high transient high voltages at lightning strikes and to limit the freewheel time for over-voltage protection. The TCR isolation switch QS2 is in an off state under the control of the compensation switching action element 100 when the power grid system fails or the current TCR branch circuit 220 has an overcurrent fault, and isolates the internal electrical equipment of the branch circuit from the power grid line.

In the TSC branch circuit 300, a corresponding TSC isolating switch QS1 and a TSC lightning arrester FV1 are sequentially arranged between a TSC current acquisition unit TA1 and a TSC compensation capacitor group C1. The TSC arrester FV1 is used to protect the electrical equipment within the TSC branch 300 from high transient high voltages in the event of a lightning strike and to limit the freewheeling time for overvoltage protection. The TSC isolating switch QS1 is in an off state under the control of the compensation switching action element 100 when the power grid system fails or the current TSC branch 300 has an overcurrent fault, and isolates the internal electrical equipment of the branch from a power grid line.

For a first example, when an inductive load in a grid system suddenly increases or a bus voltage drops (i.e., when the current system is in an abnormal operating state), a large amount of capacitive reactive power is required in the current grid system, at this time, the compensation switching element 100 sends out a trigger signal to control the TSC branch 300 to switch in operation, and simultaneously, redundant capacitive reactive power in the system after the TSC branch 300 is switched in is calculated, and a conduction angle of a TCR thyristor is adjusted to adjust output of the inductive reactive power so as to balance the redundant capacitive reactive power of the system under the abnormal operating condition, thereby improving a power factor actually input to the grid system.

As a second example, when the controller detects that the inductive load is restored or the bus voltage is stable (i.e. when the current system is in a normal operating state), the compensation switching element 100 sends out a trigger signal to control the TSC branch 300 to be switched off, and simultaneously calculates the redundant capacitive reactive power in the system after the TSC branch 300 is not switched on, and adjusts the conduction angle of the TCR thyristor, and adjusts the output of the inductive reactive power to balance the redundant capacitive reactive power in the normal operating condition of the system, thereby stabilizing the power factor and the bus voltage of the system.

The utility model discloses a static var compensator, the utility model aims at distributing partial capacity that is used for stabilizing voltage in the FC branch road among the static var compensator to the TSC branch road for the FC branch road only needs to provide the required idle work of compensation power factor (required idle work when electric wire netting system normal operation promptly) at normal during operation, reduces the loss of reactive compensator SVC at normal during operation. Furthermore, when the bus voltage drops, a part of the total capacity required by the system is distributed to the TSC branch circuit for compensation in a mode of putting the TSC branch circuit into the system, so that the bus voltage can be stabilized on the basis of reducing SVC loss, and the capacity of the reactive power compensation device is improved.

The utility model is suitable for a load consumer is more, and the great occasion of individual equipment capacity, can arouse bus voltage to reduce by a wide margin when owing to start for the reactive demand volume of the current capacitive of grid system increases suddenly. Therefore, to this kind of condition, the utility model discloses a reactive power compensator has better outstanding compensation effect, not only can reduce the loss of unnecessary power in TC branch road and the TCR branch road in the device, can also be on this basis effectual suppression system capacity reactive demand increases suddenly, and the fluctuation of the system power factor who brings stabilizes busbar voltage and system power factor.

Although the present invention has been described in connection with the above embodiments, the description is only for the convenience of understanding the present invention, and is not intended to limit the present invention. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A static var compensation apparatus, comprising:

the compensation switching action element is used for acquiring the voltage and the current of the power grid in real time, and based on the voltage and the current, when the current reactive compensator cannot provide all capacitive reactive power required by the power grid system, a TSC input instruction is generated;

the reactive compensator is connected in parallel with the power grid transmission line and compensates first reactive power which is consistent with reactive capacity required by the system in normal operation;

and the TSC branch circuit is connected in parallel with the transmission line, and controls the TSC branch circuit to be input into the transmission line after receiving the TSC input instruction so as to compensate the reactive power of the power grid system except the first reactive power required by the abnormal condition that the capacitive reactive power demand is increased.

2. The apparatus of claim 1, wherein the reactive power compensator comprises:

an FC branch connected in parallel to the transmission line and providing the first reactive power;

and the TCR branch circuit is connected in parallel with the transmission line, receives a TCR input instruction containing current TCR thyristor conduction angle information, and outputs inductive power conforming to the current TCR thyristor conduction angle under the control of the instruction so as to balance redundant capacitive reactive power of a system corresponding to the condition that the capacitive reactive power provided by the reactive power compensation device exceeds all the capacitive reactive power when the TSC branch circuit is input or not input.

3. The apparatus of claim 2, wherein the TCR circuit comprises:

a TCR current collection unit, the first end of which is connected with the transmission line;

a TCR power output unit which adopts a triangular connection structure with a first structure as a side and is connected with the second end of the TCR current acquisition unit in a three-phase triangular connection mode,

the first structure is a series structure of a thyristor device and a reactor.

4. The apparatus of claim 3, wherein the first structure comprises: the phase control circuit comprises a thyristor, and a first phase control reactor and a second phase control reactor which are respectively arranged at two ends of the thyristor.

5. The device according to claim 2, wherein an inlet end of the FC branch is connected with the transmission line, and wherein the FC branch comprises an FC current acquisition unit, an FC reactor and an FC compensation capacitor bank which are connected in sequence from the inlet end.

6. The apparatus of claim 5, wherein the reactive compensator further comprises a preset number of the FC branches.

7. The device according to any one of claims 1-6, characterized in that an incoming line end of the TSC branch circuit is connected with the transmission line, wherein the TSC branch circuit comprises a TSC current acquisition unit, a TSC compensation capacitor bank, a TSC current limiting reactor and a TSC power output unit which are sequentially connected from the incoming line end, the TSC power output unit is integrated with an anti-parallel thyristor, and the tail end of the TSC power output unit adopts a three-phase star connection mode.

8. The device according to any one of claims 2 to 6, further comprising a protection module disposed in each branch, wherein the protection module comprises a disconnector unit and a lightning arrester.

9. The device according to claim 1 or 2,

the compensation switching action element detects whether a grid voltage drop phenomenon occurs at present or whether a phenomenon that the grid voltage continuously exceeds a preset grid safe operation voltage threshold value within a preset time threshold value occurs according to the grid voltage and the grid current, and determines whether the TSC branch circuit needs to be switched according to a detection result, wherein,

and generating a corresponding TSC exit instruction when the TSC branch circuit is not required to be put into use, so that the TSC branch circuit exits from the transmission line under the control of the TSC exit instruction.

10. The apparatus of claim 2,

and the compensation switching action element is also used for acquiring the current of the incoming line end of each branch in the device in real time when the TSC branch is determined to be switched, calculating redundant capacitive reactive power of the system according to the current of each branch, the voltage of the power grid and the current of the power grid, and obtaining the corresponding current TCR thyristor conduction angle.

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