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CN-122026432-A - Chained high-voltage static var generator with power unit on-line bypass function and chained high-voltage static var generator method

CN122026432ACN 122026432 ACN122026432 ACN 122026432ACN-122026432-A

Abstract

The invention discloses a chained high-voltage static reactive power generation device with an on-line bypass function of a power unit and a method thereof, relating to the technical field of power quality control and reactive power compensation devices, comprising the power unit, wherein the power unit comprises a direct-current side loop and an alternating-current side loop, and a plurality of power units in the same phase are sequentially connected in series along the phase to form a phase-in power unit chain; the method comprises the steps of connecting a power unit chain in a three-phase into a three-phase alternating current access end in a star connection mode, connecting a bypass switch in parallel to an alternating current side loop of a corresponding power unit, arranging a sub-machine case, integrating bypass control circuits corresponding to the power units in the sub-machine case, respectively electrically connecting the bypass control circuits with the bypass switches of the corresponding power units, and arranging a main machine case which is in communication connection with the sub-machine case.

Inventors

  • KONG WEIJIE
  • ZHANG KAIQI

Assignees

  • 江苏华电仪征新能源有限公司

Dates

Publication Date
20260512
Application Date
20260212

Claims (10)

  1. 1. A chain type high-voltage static var generator with a power unit on-line bypass function, which is characterized by comprising: The power unit (100), the power unit (100) comprises a direct current side loop and an alternating current side loop, and a plurality of power units (100) in the same phase are sequentially connected in series along the phase to form a phase internal power unit chain; the three-phase power unit chains in the phases are connected into a three-phase alternating current access end (200) in a star connection mode; the bypass switch (300) is arranged in parallel on an alternating-current side loop of the corresponding power unit (100); The power unit is provided with a sub-chassis (400), a bypass control circuit (401) corresponding to the power unit (100) is integrated in the sub-chassis (400), and the bypass control circuit (401) is electrically connected with a bypass switch (300) corresponding to the power unit (100) respectively; a main chassis (500) is provided, the main chassis (500) being in communication with the sub chassis (400).
  2. 2. The chained high-voltage static var generator with power unit on-line bypass function of claim 1, wherein the power unit (100) further comprises a power conversion circuit (101) arranged therein, the power conversion circuit (101) adopts an H-bridge topology structure, a direct current side is connected with the direct current side loop, and an alternating current side is connected with the alternating current side loop.
  3. 3. The chain type high-voltage static var generator with the power unit on-line bypass function according to claim 1 or 2, wherein the three-phase alternating current access terminal (200) is electrically connected with the end part of the three-phase intra-phase power unit chain and is used for realizing the electrical access of the three-phase intra-phase power unit chain and an external three-phase alternating current system.
  4. 4. The chain type high-voltage static var generator with the power unit on-line bypass function according to claim 3, wherein the bypass switch (300) is connected with the bypass control circuit (401), and the bypass switch (300) is arranged in parallel to an alternating current side loop of the corresponding power unit (100).
  5. 5. The chain type high-voltage static var generator with the on-line bypass function of the power unit according to any one of claims 1, 2 and 4, wherein the bypass switch (300) further comprises a mechanical locking structure (301), and the mechanical locking structure (301) is mechanically linked with a switch executing mechanism of a power conversion circuit (101) of the power unit (100) and used for limiting synchronous action of the bypass switch (300) and the power conversion circuit (101) under a preset state.
  6. 6. The chain type high-voltage static var generator with the power unit on-line bypass function according to claim 2 or 4, wherein the bypass control circuit (401) is integrally arranged in the sub-chassis (400), is electrically connected with the bypass switch (300) of the corresponding power unit (100), and is used for controlling the bypass switch (300).
  7. 7. The apparatus of claim 6, wherein the main cabinet (500) is connected to the sub-cabinet (400) through a communication link, and the main cabinet (500) is not directly connected to the direct current side loop and the alternating current side loop of the power unit (100).
  8. 8. The chained high-voltage static var generator with the power unit on-line bypass function is characterized by comprising the steps of collecting running state signals of a power unit (100) in real time and generating an abnormal identification signal when the power unit (100) is detected to be in an abnormal state; after the bypass control circuit (401) receives the abnormal identification signal, the bypass control circuit executes lockout control on the power conversion circuit (101) of the abnormal power unit (100) to stop PWM pulse output; After the power conversion circuit (101) completes blocking, the bypass control circuit (401) sends an abnormal report signal to the main control system; the bypass control circuit (401) drives the bypass switch (300) to be closed, and a bypass path is formed in an alternating current side loop of the corresponding power unit (100), so that the abnormal power unit (100) is isolated by bypass from the intra-phase power unit chain; after confirming that the abnormal power units (100) are isolated by-pass, the main control system redistributes and coordinates the outputs of the rest power units (100) in the same phase so as to maintain the continuous operation of the chained high-voltage static var generator.
  9. 9. The method for generating reactive power in chained high voltage static electricity with power unit on-line bypass function as set forth in claim 8, wherein said reassigning comprises updating a current phase effective cascading unit number parameter by the master control system according to the number of remaining normal power units (100) in the current phase after confirming that the abnormal power units (100) are bypass isolated; recalculating a reference output voltage distribution value of each remaining normal power unit (100) based on the effective cascading unit quantity parameter and a target output voltage amplitude of a current phase; And (3) reassigning the voltage components originally assigned to the abnormal power units (100) to the remaining normal power units (100) in proportion, and generating a voltage reference instruction of the updated power units (100).
  10. 10. The method for generating chain type high-voltage static var with the power unit on-line bypass function according to claim 8 or 9, wherein the coordination control comprises the steps that a main control system regenerates PWM modulation control signals of all the residual normal power units (100) according to updated voltage reference instructions and sends the PWM modulation control signals to corresponding power conversion circuits (101) through the power unit control circuits so as to adjust the amplitude of the output voltage of the H bridge; simultaneously, sampling the three-phase output voltage in real time, and carrying out balance correction on the amplitude and the phase of the three-phase voltage based on the sampling result so as to ensure that the output voltage under the three-phase star connection structure is kept symmetrical; And after the voltage amplitude is restored to the set operation range, maintaining the updated modulation parameters for continuous operation.

Description

Chained high-voltage static var generator with power unit on-line bypass function and chained high-voltage static var generator method Technical Field The invention relates to the technical field of power quality control and reactive compensation devices, in particular to a chained high-voltage static reactive power generation device with a power unit on-line bypass function and a chained high-voltage static reactive power generation method. Background Along with the continuous expansion of the scale of a power system and the increasing complexity of a power grid structure, the importance of the power quality problem in a power transmission and distribution system is continuously improved, wherein the dynamic adjustment and compensation of reactive power becomes one of key technologies for guaranteeing the safe and stable operation of the power grid. The static var Generator (STATIC VAR Generator, SVG) is used as reactive compensation equipment based on the power electronic technology, and has been widely applied to high-voltage and ultra-high-voltage power systems due to the characteristics of high response speed, high regulation precision, wide operation range and the like. Aiming at the application requirement of high voltage class, the prior SVG device generally adopts a chained topology structure with a plurality of cascaded power units, and realizes high voltage output and modularized expansion by connecting a plurality of power units in series in the same phase and accessing an alternating current system in a three-phase star connection mode. However, in the engineering application process of the existing chained high-voltage static var generator, when a single power unit needs to be withdrawn for operation due to device aging, abnormal working condition or fault reasons, shutdown processing is usually required to be performed on the whole intra-phase power unit chain, or bypass operation is performed by relying on a manual switching mode, so that the continuity and usability of the overall operation of the system are affected. Part of the existing schemes introduce a bypass structure, but the existing schemes focus on simple parallel bypass of an electrical level, lack a complete bypass control system matched with a power unit control structure, an electrical isolation structure and a system level control structure, and are difficult to realize on-line bypass of the power unit under the condition that normal operation of other power units is not affected. In addition, the arrangement mode, the control level and the communication relation between the bypass control circuit and the main control system in the prior art lack of uniform and clear structural design, and the problems of complex system structure and difficult maintenance are easily caused. Disclosure of Invention The present invention has been made in view of the above-described problems. The invention solves the technical problems that when the power unit is abnormal or needs to be withdrawn and run, the existing chained high-voltage static reactive power generation device generally needs to be shut down integrally or manually to carry out bypass treatment, and has the problems of poor system running continuity, complex maintenance operation and unclear coupling between bypass control and system structure, and the problems of realizing the online bypass of the power unit and ensuring the continuous operation of the rest power units on the premise of keeping the chained high-voltage topological structure unchanged. In order to solve the technical problems, the invention provides a chained high-voltage static var generator with an on-line bypass function of power units, which comprises the power units, wherein the power units comprise a direct-current side loop and an alternating-current side loop, and a plurality of power units in the same phase are sequentially connected in series along the phase to form a phase-internal power unit chain. And the three-phase power unit chains in the phases are connected into the three-phase alternating current access terminal in a star connection mode. The bypass switch is arranged in parallel with the alternating current side loop of the corresponding power unit. The power unit is provided with a sub-chassis, a bypass control circuit corresponding to the power unit is integrated in the sub-chassis, and the bypass control circuit is electrically connected with a bypass switch of the corresponding power unit respectively. The main case is arranged and is in communication connection with the sub case. The chain type high-voltage static var generator with the power unit on-line bypass function is characterized in that the power unit further comprises a power conversion circuit which adopts an H-bridge topological structure, a direct current side is connected with the direct current side loop, and an alternating current side is connected into the alternating current side loop. The chain type high-voltage stati