Hybrid static phase modifier system and electronic equipment

Abstract

The embodiment of the invention provides a hybrid static phase modifier system and electronic equipment. The hybrid static phase modifier system comprises a control device and a power compensation device, the power compensation device comprises a high-voltage module and a low-voltage module which are connected in series to form a power chain link of the power compensation device, and the high-voltage module and the low-voltage module are connected with corresponding phases in a power grid and used for providing power compensation for the power grid; the control device collects power grid data and determines the demand according to the power grid data, and a high-low voltage module in the power compensation device changes the on-off state; the high-low voltage module provides reactive power and / or active power for the power grid through the power compensation device. The phase modifier system provided by the invention adopts a modular design, and can realize flexible configuration according to the need of a power grid through the combination of a plurality of high-voltage and low-voltage modules; the configuration number of high-voltage and low-voltage modules in the power compensation device can be changed according to requirements; the phase modifier system does not comprise a mechanical device, an electrical energy storage element is adopted to provide power compensation for a power grid, the response speed is high, and reactive power and active power can be provided for the power grid.

Description

Technical Field

[0001] The present disclosure relates to the technical field of energy storage, and in particular, to a hybrid static synchronous compensator system and an electronic device. Background Art

[0002] With the development of high proportion access of new energy and UHV DC transmission technology at the present stage, the characteristics of the power grid have changed significantly, and problems such as insufficient voltage support and reduced reactive power reserve frequently occur, threatening the security and stability of power grid operation. In response to this situation, the power compensation ability of the power grid needs to be further improved. Traditional mechanical synchronous compensators use mechanical structures, are large in size, have low flexibility, slow response, and are difficult to adapt to the rapid development of the current power grid. A static var compensator (SVC) can achieve dynamic compensation and has a fast response, but it does not have an energy storage element and cannot provide active power support for the power grid. A static synchronous compensator based on a supercapacitor can use the supercapacitor as an energy storage element to realize active support, but the cost of the supercapacitor is relatively high compared with that of a chemical energy battery; due to the rapid change of the power demand of the power grid in the application scenario, the energy storage element is frequently charged and discharged. If a chemical energy battery is used as the energy storage element, the battery life will be significantly attenuated. In summary, there is an urgent need for a new type of compensation device that can quickly respond to the reactive power of the power grid, provide active power support, and have both economy and durability. Summary of the Invention

[0003] Embodiments of the present disclosure provide a hybrid static synchronous compensator system and an electronic device to solve the disadvantages of the existing compensation device, such as low flexibility, slow response, inability to provide active power support, and poor economy.

[0004] Based on the above problems, in a first aspect, embodiments of the present disclosure provide a hybrid static synchronous compensator system, including: a control device and a power compensation device; The power compensation device includes a plurality of high and low voltage modules; the high and low voltage modules are connected in series to form a power link of the power compensation device; the power links are connected in a preset connection manner and are respectively connected to the corresponding phases in the power grid for providing power compensation for the power grid; The control device is configured to collect power grid data, determine the power grid demand according to the power grid data, and send a control instruction to control the high and low voltage modules in the power compensation device to change the switch state; The high and low voltage modules are configured to provide reactive power and / or active power to the power grid through the power compensation device according to the switch state.

[0005] In combination with the first aspect, in a possible implementation manner, the high and low voltage modules include: a power module, a capacitor module, and a battery module; The power module includes a plurality of power semiconductor devices; the power semiconductor devices include: switching transistors and diodes; The emitter of the switching transistor is connected to the positive electrode of the diode as the output terminal of the power semiconductor device, the collector of the switching transistor is connected to the negative electrode of the diode as the input terminal of the power semiconductor device, and the gate of the switching transistor receives the control instruction and controls the on / off of the switching transistor according to the control instruction; The power module is respectively connected to the capacitor module and the battery module; The capacitor module is used to provide reactive power to the power grid; The battery module is used to provide active power to the power grid; The power module is used to provide reactive power and / or active power to the power grid by controlling the on / off of the capacitor module and the battery module according to the switching state.

[0006] In a possible implementation manner in combination with the first aspect, the power module includes a first power semiconductor device, a second power semiconductor device, a third power semiconductor device, a fourth power semiconductor device, a fifth power semiconductor device, and a sixth power semiconductor device; The output terminal of the first power semiconductor device is connected to the input terminal of the second power semiconductor device as the first AC port of the high-low voltage module, and the input terminal of the first power semiconductor device is respectively connected to one end of the capacitor module and the input terminal of the third power semiconductor device; The output terminal of the second power semiconductor device is respectively connected to the other end of the capacitor module and the output terminal of the fourth power semiconductor device; The output terminal of the third power semiconductor device is respectively connected to the positive electrode of the battery module and the input terminal of the fifth power semiconductor device; The input terminal of the fourth power semiconductor device is respectively connected to the negative electrode of the battery module and the output terminal of the sixth power semiconductor device; The output terminal of the fifth power semiconductor device is connected to the input terminal of the sixth power semiconductor device as the second AC port of the high-low voltage module.

[0007] In a possible implementation manner in combination with the first aspect, the power link includes a preset number of high-low voltage modules and an output reactor; the preset number is determined according to the reactive power demand of the power grid; The first AC port of the high-low voltage module except the last-stage high-low voltage module in the power link is connected to the second AC port of another high-low voltage module, and the first AC port of the last-stage high-low voltage module in the power link is connected to the corresponding phase in the power grid through the output reactor; In the power compensation device, any two power link sections include the same number of high-voltage and low-voltage modules.

[0008] Combined with the first aspect, in a possible implementation manner, the control device determines the power demand of the power grid according to the grid data, and respectively determines the required voltage of each phase in the power grid; When the power grid demands reactive power, the control device respectively determines the capacitor voltages of each high-voltage and low-voltage module in the power link section in each preset period, and determines at least one high-voltage and low-voltage module as the first balancing module of this period for each power link section according to the difference between the capacitor voltage and the preset rated voltage; determines the switch state corresponding to the first balancing module according to the current direction of the power grid, and determines the output voltage of the first balancing module; When the power grid demands active power, the control device respectively determines the battery powers of each high-voltage and low-voltage module in the power link section in each preset period, and determines at least one high-voltage and low-voltage module as the second balancing module of this period for each power link section according to the difference between the battery power and the preset battery power; determines the switch state corresponding to the second balancing module according to the current direction of the power grid, and determines the output voltage of the second balancing module.

[0009] Combined with the first aspect, in a possible implementation manner, when a high-voltage and low-voltage module in the power link section is determined as the first balancing module, the control device determines the first reference voltage of the power link section according to the required voltage, the output voltage of the first balancing module, and the number of high-voltage and low-voltage modules in the power link section; and determines the switch states of the high-voltage and low-voltage modules in the power link section except the first balancing module according to the first reference voltage; When the first reference voltage is greater than the first threshold, it is determined that the high-voltage and low-voltage module is in the first switch state; When the first reference voltage is less than the first threshold and greater than the second threshold, it is determined that the high-voltage and low-voltage module is in the second switch state or the third switch state; When the first reference voltage is less than the second threshold, it is determined that the high-voltage and low-voltage module is in the fourth switch state.

[0010] Combined with the first aspect, in a possible implementation manner, when a high-voltage and low-voltage module in the power link section is determined as the second balancing module, the control device determines the second reference voltage of the power link section according to the required voltage, the output voltage of the second balancing module, and the number of high-voltage and low-voltage modules in the power link section; and determines the switch states of the high-voltage and low-voltage modules in the power link section except the second balancing module according to the second reference voltage; When the second reference voltage is greater than the first threshold, it is determined that the high-voltage and low-voltage module is in the first switch state; When the second reference voltage is less than the first threshold and greater than the third threshold, determine that the high-voltage and low-voltage module is in the fifth switching state or the sixth switching state; When the second reference voltage is less than the third threshold and greater than the fourth threshold, determine that the high-voltage and low-voltage module is in the second switching state or the third switching state; When the second reference voltage is less than the fourth threshold and greater than the second threshold, determine that the high-voltage and low-voltage module is in the seventh switching state or the eighth switching state; When the second reference voltage is less than the second threshold, determine that the high-voltage and low-voltage module is in the fourth switching state.

[0011] Combined with the first aspect, in a possible implementation, when the high-voltage and low-voltage module is in the first switching state, the first power semiconductor device, the fourth power semiconductor device, and the sixth power semiconductor device are turned on, the second power semiconductor device, the third power semiconductor device, and the fifth power semiconductor device are turned off, the battery module is open, and the capacitor module is turned on; When the high-voltage and low-voltage module is in the second switching state, the first power semiconductor device, the third power semiconductor device, and the fifth power semiconductor device are turned on, the second power semiconductor device, the fourth power semiconductor device, and the sixth power semiconductor device are turned off, and the battery module and the capacitor module are open; When the high-voltage and low-voltage module is in the third switching state, the first power semiconductor device, the third power semiconductor device, and the fifth power semiconductor device are turned off, the second power semiconductor device, the fourth power semiconductor device, and the sixth power semiconductor device are turned on, and the battery module and the capacitor module are open; When the high-voltage and low-voltage module is in the fourth switching state, the first power semiconductor device, the fourth power semiconductor device, and the sixth power semiconductor device are turned off, the second power semiconductor device, the third power semiconductor device, and the fifth power semiconductor device are turned on, the battery module is open, and the capacitor module is turned on.

[0012] Combined with the first aspect, in a possible implementation, when the high-voltage and low-voltage module is in the fifth switching state, the first power semiconductor device, the fourth power semiconductor device, and the fifth power semiconductor device are turned on, the second power semiconductor device, the third power semiconductor device, and the sixth power semiconductor device are turned off, and the battery module and the capacitor module are turned on; When the high-voltage and low-voltage module is in the sixth switching state, the first power semiconductor device, the third power semiconductor device, and the sixth power semiconductor device are turned on, the second power semiconductor device, the fourth power semiconductor device, and the fifth power semiconductor device are turned off, and the battery module is turned on, and the capacitor module is open; When the high - low voltage module is in the seventh switching state, the first power semiconductor device, the third power semiconductor device, and the sixth power semiconductor device are turned off, the second power semiconductor device, the fourth power semiconductor device, and the fifth power semiconductor device are turned on, the battery module is turned on, and the capacitor module is open - circuited; When the high - low voltage module is in the eighth switching state, the first power semiconductor device, the fourth power semiconductor device, and the fifth power semiconductor device are turned off, the second power semiconductor device, the third power semiconductor device, and the sixth power semiconductor device are turned on, and the battery module and the capacitor module are turned on.

[0013] Combined with the first aspect, in a possible implementation manner, when the power grid demands active power, the control device determines the switching state of the high - low voltage module according to the current direction of the power grid and the demanded voltage of the power grid; When the active power demanded by the power grid is positive and the current direction is the first direction, determine that the high - low voltage module is in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state, or the seventh switching state according to the output voltage of the corresponding power link and the demanded voltage; When the active power demanded by the power grid is positive and the current direction is the second direction, determine that the high - low voltage module is in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the sixth switching state, or the eighth switching state according to the output voltage of the corresponding power link and the demanded voltage; When the active power demanded by the power grid is negative and the current direction is the second direction, determine that the high - low voltage module is in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state, or the seventh switching state according to the output voltage of the corresponding power link and the demanded voltage; When the active power demanded by the power grid is negative and the current direction is the first direction, determine that the high - low voltage module is in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the sixth switching state, or the eighth switching state according to the output voltage of the corresponding power link and the demanded voltage.

[0014] Combined with the first aspect, in a possible implementation manner, when the current direction is the first direction and the capacitor voltage of the first equalization module is greater than the preset rated voltage, determine that the switching state of the first equalization module is the fourth switching state; When the current direction is the second direction and the capacitor voltage of the first equalization module is greater than the preset rated voltage, determine that the switching state of the first equalization module is the first switching state; When the current direction is the first direction and the capacitor voltage of the first balancing module is less than the preset rated voltage, determine that the switching state of the first balancing module is the first switching state; When the current direction is the second direction and the capacitor voltage of the first balancing module is less than the preset rated voltage, determine that the switching state of the first balancing module is the fourth switching state.

[0015] Combined with the first aspect, in a possible implementation manner, when the current direction is the first direction and the battery power of the second balancing module is greater than the preset power, determine that the switching state of the second balancing module is one of the fifth switching state or the seventh switching state; When the current direction is the first direction and the battery power of the second balancing module is less than the preset power, determine that the switching state of the second balancing module is one of the sixth switching state or the eighth switching state; When the current direction is the second direction and the battery power of the second balancing module is less than the preset power, determine that the switching state of the second balancing module is one of the fifth switching state or the seventh switching state; When the current direction is the second direction and the battery power of the second balancing module is greater than the preset power, determine that the switching state of the second balancing module is one of the sixth switching state or the eighth switching state.

[0016] In a second aspect, the present disclosure also provides an electronic device, including: a hybrid static synchronous compensator system according to any one of the first aspect.

[0017] The beneficial effects of the embodiments of the present disclosure include: A hybrid static synchronous compensator system and an electronic device provided by the embodiments of the present disclosure include: a control device and a power compensation device; the power compensation device includes a plurality of high and low voltage modules; the high and low voltage modules are connected in series to form a power link of the power compensation device; the power links are connected in a preset connection manner and are respectively connected to the corresponding phases in the power grid for providing power compensation to the power grid; the control device is used to collect power grid data, determine the power grid demand according to the power grid data, and send a control instruction to control the high and low voltage modules in the power compensation device to change the switching state; the high and low voltage modules are used to provide reactive power and / or active power to the power grid through the power compensation device according to the switching state. The synchronous compensator system provided by the present disclosure adopts a modular design. Through the combination of a plurality of high and low voltage modules, flexible configuration can be realized according to the needs of the power grid; and the configuration quantity of the high and low voltage modules in the power compensation device can be changed according to the demand; this synchronous compensator system does not include mechanical devices, uses electrical energy storage elements to provide power compensation to the power grid, has a fast response speed, and can provide reactive power and active power to the power grid. Description of the Drawings

[0018] Figure 1 Schematic diagram of the structure of the hybrid static synchronous compensator system provided by the embodiments of the present disclosure; Figure 2 Schematic diagram of the structure of the high - and low - voltage module provided by the embodiments of the present disclosure; Figure 3 Schematic diagram of the structure of the power module provided by the embodiments of the present disclosure; Figure 4 Schematic diagram of the structure of the power compensation device adopting the star - connection method provided by the embodiments of the present disclosure; Figure 5 Basic operation logic flowchart of the synchronous compensator system provided by the embodiments of the present disclosure; Figure 6 Carrier modulation strategy diagram of the synchronous compensator system during reactive power compensation provided by the embodiments of the present disclosure; Figure 7 Carrier modulation strategy diagram of the synchronous compensator system during active power support provided by the embodiments of the present disclosure. Detailed implementation manners

[0019] The embodiments of the present disclosure provide a hybrid static synchronous compensator system and an electronic device. The preferred embodiments of the present disclosure are described below with reference to the accompanying drawings of the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present disclosure and are not used to limit the present disclosure. And without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0020] The embodiments of the present disclosure provide a hybrid static synchronous compensator system, as Figure 1 shown, including: a control device 1 and a power compensation device 2; The power compensation device 2 includes a plurality of high - and low - voltage modules 21; the high - and low - voltage modules 21 are connected in series to form a power link 22 of the power compensation device 2; the power links 22 are connected in a preset connection manner and are respectively connected to the corresponding phases in the power grid, and are used to provide power compensation for the power grid; The control device 1 is used to collect power grid data, determine the power grid demand according to the power grid data, and send control instructions to control the high - and low - voltage modules 21 in the power compensation device 2 to change the switch states; The high - and low - voltage modules 21 are used to provide reactive power and / or active power to the power grid through the power compensation device 2 according to the switch states.

[0021] In the embodiments of the present disclosure, the synchronous compensator system is a device for power compensation applied in the power system, and it can be set in the converter station of DC power transmission, new - energy power generation sites (such as wind farms and photovoltaic power plants, etc.) and other weak areas of the power grid, and is used to suppress the power grid fluctuations and avoid voltage instability.

[0022] The control device 1 can be a computer device that can collect power grid data in real time, judge the current operating state of the power grid based on the power grid data, and thus determine the power grid's demand for reactive power or active power. And according to the power grid demand, it controls the switching state of the high and low voltage modules 21 in the power compensation device 2, so that the corresponding high and low voltage modules 21 provide reactive power and / or active power to the power grid, thereby enabling the power compensation device 2 to provide power compensation for the power grid.

[0023] The power compensation device 2 can be a cascaded complete set of devices composed of multiple power links 22. The power links 22 in the power compensation device 2 are formed by connecting multiple high and low voltage modules 21 in series according to a certain arrangement. The power links 22 are connected according to a preset connection method, and each power link 22 is connected to one phase in the power grid for providing power compensation. Among them, the preset connection method can be star connection, delta connection, double-star connection, etc., which can be selected according to the actual situation.

[0024] Compared with the traditional mechanical synchronous condenser, the synchronous condenser system provided by the present disclosure uses electrical components as energy storage units, has no mechanical structure, adopts a static structure, and is composed of power electronic devices and a control device, reducing the volume and having a fast response speed; at the same time, it adopts a modular configuration method, and can flexibly change the performance of the synchronous condenser according to the power grid situation, facilitating expansion and maintenance, and being able to adapt to various power grid situations. And compared with the SVC, the synchronous condenser system of the present disclosure can provide active power support for the power grid.

[0025] In another embodiment provided by the present disclosure, as Figure 2 shown, the high and low voltage module 21 includes: a power module 211, a capacitor module 212, and a battery module 213; The power module 211 includes multiple power semiconductor devices; the power semiconductor devices include: switching tubes and diodes; The emitter of the switching tube is connected to the positive pole of the diode as the output end of the power semiconductor device, the collector of the switching tube is connected to the negative pole of the diode as the input end of the power semiconductor device, and the gate of the switching tube receives a control instruction and controls the on-off of the switching tube according to the control instruction; The power module 211 is respectively connected to the capacitor module 212 and the battery module 213; The capacitor module 212 is used to provide reactive power to the power grid; The battery module 213 is used to provide active power to the power grid; The power module 211 is used to provide reactive power and / or active power to the power grid by controlling the on-off of the capacitor module 212 and the battery module 213 according to the switching state.

[0026] In the embodiments of the present disclosure, the high - low voltage module 21 includes a capacitor module 212, a battery module 213, and a power module 211. The capacitor module 212 may include at least one capacitor. As an energy storage element, the capacitor module stores electric - field energy and provides capacitive reactive power to the power grid to offset the inductive reactive power generated by inductive loads, thereby improving the power factor of the power - grid system and voltage stability.

[0027] The battery module 213 may include at least one battery. As an energy storage element, the battery module stores chemical energy. When the power grid has a positive demand for active power, it can convert chemical energy into electrical energy and output electrical energy to the power grid, thereby providing active power to the power grid to meet the demand of load consumption; when the demand for active power from the power grid is negative, it can absorb active power by charging the battery module 213.

[0028] The battery module in the present disclosure may be a chemical - energy battery, which has an obvious cost advantage compared with supercapacitors.

[0029] The power module 211 may include multiple power semiconductor devices. By controlling the power semiconductor devices to form a specific on - off combination, the on - off of the capacitor module 212 and the battery module 213 is controlled, so as to output corresponding power to the power grid.

[0030] Among them, the power semiconductor device is composed of a switching tube and a diode. The switching tube may be an insulated - gate bipolar transistor (IGBT, Insulated Gate Bipolar Transistor). By applying a signal to the gate, the conduction or cut - off between the collector and the emitter can be controlled, thereby controlling the on - off of the switching tube. The diode is used to provide a path for the reverse current, prevent the switching tube from being reverse - broken down, protect the switching tube and maintain the normal operation of the circuit.

[0031] Furthermore, the capacitance of the capacitor module 212 can be determined according to the following formula (1).

[0032] (1) Where is the minimum required capacitance of the capacitor module 212; is the rated voltage of the capacitor module 212; is the reactive power capacity of the high - low voltage module 21; is the allowable voltage fluctuation rate, generally with a value not greater than 5%; ω is the power - grid angular frequency.

[0033] Furthermore, the battery module 213 may be formed by connecting multiple battery cells in series. The number of series - connected battery cells of the battery module 213 can be determined by first determining the number of high - low voltage modules 21 of the power - chain link 22.

[0034] The number of high - and - low - voltage modules 21 can be determined according to the following formula (2).

[0035] (2) Wherein, is the number of high - and - low - voltage modules 21; is the maximum reactive power demand; is the rated current on the AC side of the module; is the rated voltage on the AC side of the module.

[0036] The number of series - connected battery cells of the battery module 213 can be determined according to the following formula (3).

[0037] (3) Wherein, is the number of series - connected battery cells of the battery module 213; is the maximum active power demand; is the charge - discharge time; is the redundancy factor; is the capacity of the battery cell; is the rated voltage of the battery cell; is the power conversion efficiency, which can be determined according to the technical parameters of the battery cell; is the depth of discharge of the battery cell.

[0038] The above - mentioned and can be determined in advance during the design process according to the load type, power, power factor and operating state of the power grid, as well as the dynamic requirements under various working conditions.

[0039] Through the flexible configuration of the capacitor module and the battery module, the hybrid static synchronous compensator system provided by the present disclosure achieves comprehensive coverage of various power - grid compensation requirements, and can adjust the capacitor module and the battery module accordingly according to the development and change of the power grid, realizing the economical use of resources.

[0040] In another embodiment provided by the present disclosure, as Figure 3 shown, the power module 211 includes a first power semiconductor device 2111, a second power semiconductor device 2112, a third power semiconductor device 2113, a fourth power semiconductor device 2114, a fifth power semiconductor device 2115 and a sixth power semiconductor device 2116; The output end of the first power semiconductor device 2111 is connected to the input end of the second power semiconductor device 2112, serving as the first AC port 2117 of the high - and - low - voltage module 21. The input end of the first power semiconductor device 2111 is respectively connected to one end of the capacitor module 212 and the input end of the third power semiconductor device 2113; The output terminals of the second power semiconductor device 2112 are respectively connected to the other end of the capacitor module 212 and the output terminal of the fourth power semiconductor device 2114; The output terminals of the third power semiconductor device 2113 are respectively connected to the positive electrode of the battery module 213 and the input terminal of the fifth power semiconductor device 2115; The input terminals of the fourth power semiconductor device 2114 are respectively connected to the negative electrode of the battery module 213 and the output terminal of the sixth power semiconductor device 2116; The output terminal of the fifth power semiconductor device 2115 is connected to the input terminal of the sixth power semiconductor device 2116, serving as the second AC port 2118 of the high and low voltage module 21.

[0041] In the embodiment of the present disclosure, the first power semiconductor device 2111 and the second power semiconductor device 2112 form the high-voltage devices of the power module 211. In practical applications, the components in the high-voltage devices need to withstand higher voltages than the low-voltage devices. To avoid breakdown damage, semiconductor devices with a higher withstand voltage rating can be selected. For the semiconductor devices (including: switching tubes and diodes) in the first power semiconductor device 2111 and the second power semiconductor device 2112, their voltage stress levels should be greater than the rated voltage of the capacitor module 212 . Considering the influence of voltage changes during the charging and discharging process of the capacitor, sufficient safety margins need to be designed in actual engineering.

[0042] The third power semiconductor device 2113, the fourth power semiconductor device 2114, the fifth power semiconductor device 2115, and the sixth power semiconductor device 2116 together form the low-voltage devices of the power module 211. In practical applications, the low-voltage devices are connected to other high and low voltage modules 21, and semiconductor devices with a relatively lower withstand voltage rating can be selected. Among them, the voltage stress levels of the third power semiconductor device 2113 and the fourth power semiconductor device 2114 should be greater than , which is the rated voltage of the battery module 213, . The voltage stress levels of the third power semiconductor device 2113 and the fourth power semiconductor device 2114 should be greater than . Considering the influence of voltage changes during the charging and discharging processes of the battery and the capacitor, sufficient safety margins need to be designed in actual engineering.

[0043] In another embodiment provided by the present disclosure, the power link 22 includes a preset number of high and low voltage modules 21 and an output reactor; the preset number is determined according to the reactive power demand of the power grid; The first AC port 2117 of the high-voltage and low-voltage module in the power link 22, except for the last-stage high-voltage and low-voltage module, is connected to the second AC port 2118 of another high-voltage and low-voltage module. The first AC port 2117 of the last-stage high-voltage and low-voltage module in the power link 22 is connected to the corresponding phase in the power grid through an output reactor; In the power compensation device 2, the number of high-voltage and low-voltage modules 21 included in any two power links 22 is the same.

[0044] In the embodiment of the present disclosure, the preset number can first determine the number of high-voltage and low-voltage modules of the entire power compensation device according to the above formula (2), and then further determine the number of high-voltage and low-voltage modules of each power link of the power compensation device.

[0045] The power link 22 of the power compensation device 2 is composed of a plurality of high-voltage and low-voltage modules 21 and output reactors connected in series. Each power link 22 is connected to one phase in the power grid, and provides power compensation for the power grid through a complete set of devices (i.e., the power compensation device). Taking the power link 22 in the power compensation device 2 adopting a star connection method as an example, as Figure 4 shown, the low-voltage device side of the first high-voltage and low-voltage module of each power link 22 is connected through the second AC port 2118. The low-voltage device side of the secondary high-voltage and low-voltage module in the power link 22 is connected to the high-voltage device side of the first high-voltage and low-voltage module (i.e., the second AC port 2118 of the secondary high-voltage and low-voltage module is connected to the first AC port 2117 of the first high-voltage and low-voltage module). In this way, the high-voltage and low-voltage modules 21 in the power link 22 are connected in series; the first AC port 2117 of the last-stage high-voltage and low-voltage module in the power link 22 is connected to one phase in the power grid through the output reactor 23.

[0046] The reactor can achieve the dynamic balance of the power system through its inductance characteristics during the reactive power compensation process.

[0047] In another embodiment provided by the present disclosure, the control device 1 determines the power demand in the power grid according to the grid data, and respectively determines the required voltage of each phase in the power grid; In the case where the power grid demands reactive power, the control device respectively determines the capacitor voltage of each high-voltage and low-voltage module in the power link in each preset period, and determines at least one high-voltage and low-voltage module for each power link as the first equalization module of this period according to the difference between the capacitor voltage and the preset rated voltage; determines the switch state of the corresponding first equalization module according to the current direction of the power grid, and determines the output voltage of the first equalization module; When the power grid requires active power, the control device determines the battery power of each high and low voltage module in the power chain in each preset cycle, and determines at least one high and low voltage module for each power chain as the second balancing module of this cycle according to the difference between the battery power and the preset battery power; determines the switching state of the corresponding second balancing module according to the current direction of the power grid, and determines the output voltage of the second balancing module.

[0048] In the embodiment of the present disclosure, the control device 1 can collect grid data, where the grid data can include: grid voltage, grid current and grid frequency. The control device 1 can use the grid control algorithm to calculate the grid demand power, and then solve the demand voltage of each phase. The demand voltage is the voltage level that the power grid needs to maintain during operation in order to maintain the stability of the entire system and the quality of power supply. In this disclosure, the demand voltage is used as one of the reference bases for power compensation.

[0049] When the power grid requires reactive power, the control device 1 detects the capacitor voltage of the capacitor module 212 of all the high and low voltage modules 21 in the power chain link 22 in each preset cycle, compares the capacitor voltage with the preset rated voltage, and determines the high and low voltage module 21 with the largest absolute value of the difference between the two for each power chain link, and determines this high and low voltage module 21 as the first balancing module in this preset cycle. The preset rated voltage is a value predetermined according to the rated voltage of the capacitor. When the capacitor voltage is greater than this value, it can be considered that the module voltage is too high, and it is necessary to select a switch state that can discharge the capacitor; when the capacitor voltage is less than this value, it can be considered that the module voltage is too low, and it is necessary to select a switch state that can charge the capacitor. Due to the different directions of the grid current under the same switch state, the charging and discharging states of the capacitor module will be different, so the control device needs to switch the switch state of the first balancing module according to the current direction. That is, when the grid requires reactive power, the switch state of the first balancing module can be determined as a switch state in which the battery module is disconnected and the capacitor module can be charged and discharged (i.e., the first switch state and the fourth switch state).

[0050] The first balancing module can be the high- and low-voltage module with the largest deviation from the rated voltage in each power link that provides reactive power to the power grid. The control module can sample the output voltage of the high- and low-voltage module, and determine the corresponding reference voltage for other high- and low-voltage modules in the power link in which it is located based on the output voltage; and further formulate a corresponding modulation strategy for the high- and low-voltage modules in the power link based on this reference voltage (i.e., adjust the switch state of the high- and low-voltage modules).

[0051] When the power grid demands active power, the control device 1 detects the power levels of the battery modules 213 of all the high- and low-voltage modules 21 in the power link 22 in each preset period, and compares the power levels of the battery modules 213 with a preset battery power level. The preset battery power level is a predetermined value. When the power level of a battery module is greater than this value, it can be considered that the module can supply active power to the power grid, and the switch state that enables the battery module to discharge needs to be selected; when the battery power level is less than this value, it can be considered that the module can absorb active power from the power grid, and the switch state that enables the battery module to charge needs to be selected.

[0052] When the active power demanded by the power grid is positive, determine the high- and low-voltage module with the highest power level in each power link, and determine this high- and low-voltage module as the second balancing module in this preset period, and select the switch state that enables the battery to discharge according to the grid current.

[0053] When the active power demanded by the power grid is negative, determine the high- and low-voltage module with the lowest power level in each power link. Determine this high- and low-voltage module as the second balancing module in this preset period, and select the switch state that enables the battery to discharge according to the grid current.

[0054] The second balancing module can be the high- and low-voltage module with the largest deviation from the preset battery power level in each power link that supplies active power to the power grid. The control module can sample the output voltage of this high- and low-voltage module, and determine the corresponding reference voltage for other high- and low-voltage modules in the power link where it is located according to the output voltage; and further formulate the corresponding modulation strategy (i.e., adjust the switch state of the high- and low-voltage module) for the high- and low-voltage modules in this power link according to this reference voltage.

[0055] Among them, the preset period can be an integer multiple of the fundamental period, and the fundamental period represents the shortest time interval required for the signal to repeat itself; the preset battery power level can be the average power level of the battery modules 213 of all the high- and low-voltage modules 21 in the power link 22.

[0056] In each preset period, according to the power grid power demand, reselect a new high- and low-voltage module 21 as the first or second balancing module to balance the state deviation of the battery and capacitor caused by component inconsistency during system operation.

[0057] It should be noted that the number of balancing modules selected in each period in the above implementation process can be adjusted according to the actual power grid demand. For example, two high- and low-voltage modules are determined as the first or second balancing modules in this period for each power link, and its specific implementation method is exactly the same as the idea of this embodiment.

[0058] The above steps can be executed as Figure 5 the flow schematic diagram shown.

[0059] In another embodiment provided by the present disclosure, when a high-voltage and low-voltage module in the power link is determined to be the first equalization module, the control device determines the first reference voltage of the power link according to the required voltage, the output voltage of the first equalization module, and the number of high-voltage and low-voltage modules in the power link; and determines the switching states of the high-voltage and low-voltage modules in the power link except the first equalization module according to the first reference voltage. When the first reference voltage is greater than the first threshold, it is determined that the high-voltage and low-voltage module is in the first switching state. When the first reference voltage is less than the first threshold and greater than the second threshold, it is determined that the high-voltage and low-voltage module is in the second switching state or the third switching state. When the first reference voltage is less than the second threshold, it is determined that the high-voltage and low-voltage module is in the fourth switching state.

[0060] In the embodiment of the present disclosure, for the high-voltage and low-voltage module 21 selected as the first equalization module or the second equalization module, the control device 1 determines the output voltage of the high-voltage and low-voltage module 21, and obtains the reference voltage of the corresponding power link according to the required voltage of the corresponding phase in the power grid and the number of high-voltage and low-voltage modules 21 in the power link 22 corresponding to this phase. Among them, the reference voltage can be determined according to the following formula (4).

[0061] (4) Among them, is the reference voltage; is the required voltage of the corresponding phase, is the output voltage of the corresponding high-voltage and low-voltage module (i.e., the first equalization module or the second equalization module).

[0062] The first reference voltage can be the modulation voltage of each high-voltage and low-voltage module 21 of the power link 22 during the process of providing reactive power to the power grid. The control device 1 can send a control command according to this modulation voltage to change the switching states of each high-voltage and low-voltage module in the power link except the first equalization module.

[0063] The first threshold can be the voltage value at the connection between the power module 211 and the capacitor module 212 in the high-voltage and low-voltage module 21 , and the second threshold can be .

[0064] That is, for each high-voltage and low-voltage module, when , the control device 1 controls the corresponding high-voltage and low-voltage module to be in the first switching state; when , the control device 1 controls the corresponding high-voltage and low-voltage module to be in the second or third switching state; when , the control device 1 controls the corresponding high-voltage and low-voltage module to be in the fourth switching state. Among them, is the first reference voltage. A phase difference with the same interval can be set between the carriers of different high- and low-voltage modules, and the phase shift angle can be or , so as to improve the overall output harmonic performance of the device.

[0065] Taking the voltage output at the connection of the power module and the capacitor module as a triangular wave as an example, the carrier modulation strategy of the synchronous condenser system during reactive power compensation is as Figure 6 shown.

[0066] In another embodiment provided by the present disclosure, when a high- and low-voltage module in the power link is determined to be the second balancing module, the control device determines the second reference voltage of the power link according to the required voltage, the output voltage of the second balancing module, and the number of high- and low-voltage modules in the power link; and determines the switching states of the high- and low-voltage modules in the power link except the second balancing module according to the second reference voltage; When the second reference voltage is greater than the first threshold, it is determined that the high- and low-voltage module 21 is in the first switching state; When the second reference voltage is less than the first threshold and greater than the third threshold, it is determined that the high- and low-voltage module 21 is in the fifth or sixth switching state; When the second reference voltage is less than the third threshold and greater than the fourth threshold, it is determined that the high- and low-voltage module 21 is in the second or third switching state; When the second reference voltage is less than the fourth threshold and greater than the second threshold, it is determined that the high- and low-voltage module 21 is in the seventh or eighth switching state; When the second reference voltage is less than the second threshold, it is determined that the high- and low-voltage module 21 is in the fourth switching state.

[0067] In the embodiment of the present disclosure, the second reference voltage can be the modulation voltage of each high- and low-voltage module 21 of the power link 22 during the process of providing active power to the power grid. The control device 1 can send control instructions according to this modulation voltage to change the switching states of each high- and low-voltage module 21 in the corresponding power link except the second balancing module.

[0068] Among them, the third threshold can be , and the fourth threshold can be .

[0069] That is, for each high- and low-voltage module, when is the case, the control device 1 controls the corresponding high- and low-voltage module to be in the first switching state; when is the case, the control device 1 controls the corresponding high- and low-voltage module to be in the fifth or sixth switching state; when is the case, the control device 1 controls the corresponding high- and low-voltage module to be in the second or third switching state; when In this case, the control device 1 controls the corresponding high- and low-voltage module to be in the seventh or eighth switching state; when In this case, the control device 1 controls the corresponding high- and low-voltage module to be in the third switching state. Among them, is the second reference voltage.

[0070] Taking the voltage output at the connection between the power module and the capacitor module as a triangular wave as an example, the carrier modulation strategy of the synchronous condenser system during active power support is as Figure 7 shown.

[0071] In another embodiment provided by the present disclosure, when the high- and low-voltage module 21 is in the first switching state, the first power semiconductor device 2111, the fourth power semiconductor device 2114, and the sixth power semiconductor device 2116 are turned on, and the second power semiconductor device 2112, the third power semiconductor device 2113, and the fifth power semiconductor device 2115 are turned off. The battery module 213 is open-circuited, and the capacitor module 212 is turned on; When the high- and low-voltage module 21 is in the second switching state, the first power semiconductor device 2111, the third power semiconductor device 2113, and the fifth power semiconductor device 2115 are turned on, and the second power semiconductor device 2112, the fourth power semiconductor device 2114, and the sixth power semiconductor device 2116 are turned off. The battery module 213 and the capacitor module 212 are open-circuited; When the high- and low-voltage module 21 is in the third switching state, the first power semiconductor device 2111, the third power semiconductor device 2113, and the fifth power semiconductor device 2115 are turned off, and the second power semiconductor device 2112, the fourth power semiconductor device 2114, and the sixth power semiconductor device 2116 are turned on. The battery module 213 and the capacitor module 212 are open-circuited; When the high- and low-voltage module 21 is in the fourth switching state, the first power semiconductor device 2111, the fourth power semiconductor device 2114, and the sixth power semiconductor device 2116 are turned off, and the second power semiconductor device 2112, the third power semiconductor device 2113, and the fifth power semiconductor device 2115 are turned on. The battery module 213 is open-circuited, and the capacitor module 212 is turned on.

[0072] In the embodiment of the present disclosure, the switching states of the first power semiconductor device 2111 and the second power semiconductor device 2112, the third power semiconductor device 2113 and the fourth power semiconductor device 2114, and the fifth power semiconductor device 2115 and the sixth power semiconductor device 2116 of the high- and low-voltage module 21 are complementary.

[0073] When the battery module 213 is in an open circuit state, the high and low voltage module 21 cannot supply active power to the power grid. When the capacitor module 212 is in a conducting state, it can supply reactive power to the power grid and charge and discharge the capacitor module 212 according to the current direction. When both the battery module 213 and the capacitor module 212 are in an open circuit state, the high and low voltage module 21 has no impact on the power grid.

[0074] In another embodiment provided by the present disclosure, when the high and low voltage module 21 is in the fifth switching state, the first power semiconductor device 2111, the fourth power semiconductor device 2114, and the fifth power semiconductor device 2115 are conducting, the second power semiconductor device 2112, the third power semiconductor device 2113, and the sixth power semiconductor device 2116 are turned off, and the battery module 213 and the capacitor module 212 are conducting; When the high and low voltage module 21 is in the sixth switching state, the first power semiconductor device 2111, the third power semiconductor device 2113, and the sixth power semiconductor device 2116 are conducting, the second power semiconductor device 2112, the fourth power semiconductor device 2114, and the fifth power semiconductor device 2115 are turned off, the battery module 213 is conducting, and the capacitor module 212 is in an open circuit state; When the high and low voltage module 21 is in the seventh switching state, the first power semiconductor device 2111, the third power semiconductor device 2113, and the sixth power semiconductor device 2116 are turned off, the second power semiconductor device 2112, the fourth power semiconductor device 2114, and the fifth power semiconductor device 2115 are conducting, the battery module 213 is conducting, and the capacitor module 212 is in an open circuit state; When the high and low voltage module 21 is in the eighth switching state, the first power semiconductor device 2111, the fourth power semiconductor device 2114, and the fifth power semiconductor device 2115 are turned off, the second power semiconductor device 2112, the fourth power semiconductor device 2114, and the sixth power semiconductor device 2116 are conducting, and the battery module 213 and the capacitor module 212 are conducting.

[0075] In the embodiment of the present disclosure, when the battery module 213 is in a conducting state, the high and low voltage module 21 can supply active power to the power grid and charge or discharge the battery module according to the positive or negative of the active power demand of the power grid. When both the battery module 213 and the capacitor module 212 are in a conducting state, the high and low voltage module 21 can supply active power and reactive power to the power grid.

[0076] Here, a switching state table of the high and low voltage module as shown in Table 1 below is provided as an example.

[0077]

[0078] Table 1 Switching State Table of High and Low Voltage Module In the above table, 1 represents that the power semiconductor device is in the on state, and 0 represents that the power semiconductor device is in the off state; is the rated voltage of the capacitor module 212, is the rated voltage of the battery module 213.

[0079] According to the above table, it can be seen that the high-low voltage module 21 provided by the present disclosure can provide a total of eight switching states and output seven level states; if then the input level state is five. Under each level state, the battery module 213 and the capacitor module 212 have different charge-discharge relationships according to different current directions.

[0080] In another embodiment provided by the present disclosure, when the power grid demands active power, the control device determines the switching state of the high-low voltage module according to the current direction of the power grid and the required voltage of the power grid; When the active power demanded by the power grid is positive and the current direction is the first direction, according to the output voltage and the required voltage of the corresponding power link, it is determined that the high-low voltage module is one of the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state or the seventh switching state; When the active power demanded by the power grid is positive and the current direction is the second direction, according to the output voltage and the required voltage of the corresponding power link, it is determined that the high-low voltage module is one of the first switching state, the second switching state, the third switching state, the fourth switching state, the sixth switching state or the eighth switching state; When the active power demanded by the power grid is negative and the current direction is the second direction, according to the output voltage and the required voltage of the corresponding power link, it is determined that the high-low voltage module is one of the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state or the seventh switching state; When the active power demanded by the power grid is negative and the current direction is the first direction, according to the output voltage and the required voltage of the corresponding power link, it is determined that the high-low voltage module is one of the first switching state, the second switching state, the third switching state, the fourth switching state, the sixth switching state or the eighth switching state.

[0081] In the embodiment of the present disclosure, the current can be the phase current of each power grid , the first direction can refer to , the second direction can refer to .

[0082] Since the current direction in the AC power grid will change periodically, if the high-low voltage module 21 is in the same switching state, due to the change of the current direction, it may cause the battery module 213 to frequently change the charge-discharge state, thereby reducing the battery life.

[0083] The control device 1 provided by the embodiments of the present disclosure can also change the switching state of the high- and low-voltage module 21 according to the direction of the current, so that the battery module 213 maintains a charging or discharging state.

[0084] The charging and discharging requirements of the battery module 213 can be determined according to the comparison between the total voltage output by the power link 22 and the required voltage of the corresponding phase. Among them, the total voltage output by the power link 22 can be determined according to the following formula (5): (5) Among them, is the total voltage output by the power link 22; is the output voltage of the -th high- and low-voltage module 21 corresponding to the power link 22; is the number of sub-modules in the case where the output voltage is ; characterizes the switching state of the high- and low-voltage module 21.

[0085] The control device can adjust the switching state of each high- and low-voltage module according to the total voltage output by the power link, so that so that the synchronous condenser can meet the current power grid power demand.

[0086] In the case where the battery module 213 requires active power discharge, the control device 1 will change the switching state of the corresponding high- and low-voltage module 21 according to the current direction. When , the switching state is determined to be the fifth switching state or the seventh switching state; when , the switching state is determined to be the sixth switching state or the eighth switching state.

[0087] In the case where the battery module 213 requires active power charging, the control device 1 will change the switching state of the corresponding high- and low-voltage module 21 according to the current direction. When , the switching state is determined to be the fifth switching state or the seventh switching state; when , the switching state is determined to be the sixth switching state or the eighth switching state.

[0088] Using this method can avoid the repeated switching of the charging and discharging states of the battery module 213 in different control cycles, and avoid the situation of simultaneous discharging and charging, thereby improving the life of the battery module.

[0089] In another embodiment provided by the present disclosure, when the current direction is the first direction and the capacitor voltage of the first equalization module is greater than the preset rated voltage, the switching state of the first equalization module is determined to be the fourth switching state; When the current direction is the second direction and the capacitor voltage of the first balancing module is greater than the preset rated voltage, determine the switching state of the first balancing module as the first switching state; When the current direction is the first direction and the capacitor voltage of the first balancing module is less than the preset rated voltage, determine the switching state of the first balancing module as the first switching state; When the current direction is the second direction and the capacitor voltage of the first balancing module is less than the preset rated voltage, determine the switching state of the first balancing module as the fourth switching state.

[0090] In the embodiments of the present disclosure, the first balancing module is the high-low voltage module with the largest deviation between the capacitor voltage and the rated voltage value in a power link. When the capacitor voltage of the first balancing module is greater than the rated voltage, it indicates that the capacitor module of this high-low voltage module stores a relatively large amount of electric charge, and continuous discharging is required to reduce the amount of electric charge stored inside it, so as to lower its output voltage and thus maintain the stability of the power link operation. In this case, the switching state of the first balancing module can be determined to be in the switching state that can discharge the capacitor according to the current direction.

[0091] When the capacitor voltage of the first balancing module is less than the rated voltage, it indicates that the capacitor module of this high-low voltage module stores a relatively small amount of electric charge, and continuous charging is required to increase the amount of electric charge stored inside it, so as to raise its output voltage. In this case, the switching state of the first balancing module can be determined to be in the switching state that can charge the capacitor according to the current direction.

[0092] In another embodiment provided by the present disclosure, when the current direction is the first direction and the battery power of the second balancing module is greater than the preset power, determine the switching state of the second balancing module as one of the fifth switching state or the seventh switching state; When the current direction is the first direction and the battery power of the second balancing module is less than the preset power, determine the switching state of the second balancing module as one of the sixth switching state or the eighth switching state; When the current direction is the second direction and the battery power of the second balancing module is less than the preset power, determine the switching state of the second balancing module as one of the fifth switching state or the seventh switching state; When the current direction is the second direction and the battery power of the second balancing module is greater than the preset power, determine the switching state of the second balancing module as one of the sixth switching state or the eighth switching state.

[0093] In an embodiment of the present disclosure, the second balancing module is the high-voltage and low-voltage module with the largest deviation between the battery module's power and the rated power in a power link. When the power of the battery module is greater than the rated power, it indicates that the power stored in the battery module is higher than that stored in other high-voltage and low-voltage modules in this power link. It is necessary to continuously discharge the second balancing module so that the stored power returns to a level close to that of other high-voltage and low-voltage modules in the power link, thereby making the active power output by the power link stable and smooth. In this case, the switching state of the second balancing module can be determined according to the current direction to a switching state that can discharge the battery module.

[0094] When the power of the battery module is less than the rated power, it indicates that the power stored in the battery module is lower than that stored in other high-voltage and low-voltage modules in this power link. It is necessary to continuously charge the second balancing module so that the stored power is increased to a level close to that of other high-voltage and low-voltage modules in the power link, thereby enabling the power link to stably absorb active power. In this case, the switching state of the second balancing module can be determined according to the current direction to a switching state that can charge the battery module.

[0095] The present disclosure also provides an electronic device, including a hybrid static synchronous compensator system provided in any of the above embodiments.

[0096] Through the description of the above embodiments, those skilled in the art can clearly understand that the embodiments of the present disclosure can be implemented by hardware or by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solutions of the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in various embodiments of the present disclosure.

[0097] Those skilled in the art can understand that the drawings are only schematic diagrams of a preferred embodiment, and the modules or processes in the drawings are not necessarily essential for implementing the present disclosure.

[0098] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be correspondingly changed and located in one or more devices different from this embodiment. The modules of the above embodiments can be combined into one module, or further split into multiple sub-modules.

[0099] The serial numbers of the above embodiments of the present disclosure are only for description and do not represent the advantages or disadvantages of the embodiments.

[0100] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure is also intended to include these changes and modifications.

Claims

1. A hybrid static phase condenser system, characterized in that: include: Control devices and power compensation devices; The power compensation device comprises a plurality of high and low voltage modules; The high and low voltage modules are connected in series to form a power chain link of a power compensation device; the power chain links are connected in a preset connection mode and are respectively connected to corresponding phases in a power grid to provide power compensation for the power grid; The control device is used to collect power grid data, determine power grid demand according to the power grid data, and send control instructions to control the high and low voltage modules in the power compensation device to change the switch state; The high and low voltage modules are used to provide reactive power and / or active power to the power grid through a power compensation device according to the switch state.

2. The system according to claim 1, characterized in that The high and low voltage modules include: a power module, a capacitor module and a battery module; The power module includes a plurality of power semiconductor devices; the power semiconductor devices include: a switch tube and a diode; The emitter of the switch tube is connected to the positive electrode of the diode as the output end of the power semiconductor device, the collector of the switch tube is connected to the negative electrode of the diode as the input end of the power semiconductor device, and the gate of the switch tube receives the control instruction and controls the on and off of the switch tube according to the control instruction; The power module is connected to the capacitor module and the battery module respectively; The capacitor module is used to provide reactive power to the power grid; The battery module is used to provide active power to the power grid; The power module is used to provide reactive power and / or active power to the power grid by controlling the connection and disconnection of the capacitor module and the battery module according to the switch state.

3. The system according to claim 2, characterized in that The power module comprises a first power semiconductor device, a second power semiconductor device, a third power semiconductor device, a fourth power semiconductor device, a fifth power semiconductor device and a sixth power semiconductor device; The output end of the first power semiconductor device is connected to the input end of the second power semiconductor device, serving as the first AC port of the high and low voltage modules, and the input end of the first power semiconductor device is respectively connected to one end of the capacitor module and the input end of the third power semiconductor device; The output end of the second power semiconductor device is respectively connected to the other end of the capacitor module and the output end of the fourth power semiconductor device; The output end of the third power semiconductor device is respectively connected to the positive electrode of the battery module and the input end of the fifth power semiconductor device; The input end of the fourth power semiconductor device is respectively connected to the negative electrode of the battery module and the output end of the sixth power semiconductor device; The output end of the fifth power semiconductor device is connected to the input end of the sixth power semiconductor device, serving as a second AC port of the high and low voltage module.

4. The system according to claim 1, characterized in that The power chain includes a preset number of high and low voltage modules and output reactors; the preset number is determined according to the reactive power demand of the power grid; The first AC port of the high and low voltage modules other than the final high and low voltage module in the power chain is connected to the second AC port of another high and low voltage module, and the first AC port of the final high and low voltage module in the power chain is connected to the corresponding phase in the power grid through the output reactor; In the power compensation device, any two power links include the same number of high and low voltage modules.

5. The system according to claim 3, characterized in that The control device determines the power demand of the power grid according to the power grid data, and respectively determines the required voltage of each phase in the power grid; In the case where the grid requires reactive power, the control device determines the capacitor voltage of each high-voltage and low-voltage module in the power chain link in each preset cycle, and determines at least one high-voltage and low-voltage module for each power chain link as the first balancing module of the current cycle according to the difference between the capacitor voltage and the preset rated voltage; Determine a switch state of a corresponding first balancing module according to a current direction of the power grid, and determine an output voltage of the first balancing module; In the case where the power grid requires active power, the control device determines the battery power of each high and low voltage module in the power link in each preset cycle, and determines at least one high and low voltage module for each power link as the second balancing module of this cycle according to the difference between the battery power and the preset battery power; determines the switch state of the corresponding second balancing module according to the current direction of the power grid, and determines the output voltage of the second balancing module.

6. The system according to claim 5, characterized in that In the case where a high-low voltage module in a power link is determined as a first balancing module, the control device determines a first reference voltage of the power link according to the required voltage, the output voltage of the first balancing module and the number of high-low voltage modules in the power link; and determines the switch states of the high-low voltage modules in the power link except the first balancing module according to the first reference voltage; When the first reference voltage is greater than a first threshold, determining that the high and low voltage modules are in a first switch state; When the first reference voltage is less than a first threshold value and greater than a second threshold value, determining that the high and low voltage modules are in a second switch state or a third switch state; When the first reference voltage is less than the second threshold, the high and low voltage modules are determined to be in the fourth switch state.

7. The system according to claim 5, characterized in that In the case where a high-low voltage module in the power link is determined as a second balancing module, the control device determines a second reference voltage of the power link according to the required voltage, the output voltage of the second balancing module and the number of high-low voltage modules in the power link; and determines the switch states of the high-low voltage modules in the power link except the second balancing module according to the second reference voltage; When the second reference voltage is greater than the first threshold, determining that the high and low voltage modules are in the first switch state; When the second reference voltage is less than the first threshold and greater than the third threshold, determining that the high and low voltage modules are in the fifth switch state or the sixth switch state; When the second reference voltage is less than the third threshold and greater than the fourth threshold, determining that the high and low voltage modules are in the second switch state or the third switch state; When the second reference voltage is less than the fourth threshold value and greater than the second threshold value, determining that the high and low voltage modules are in the seventh switch state or the eighth switch state; When the second reference voltage is less than the second threshold, the high and low voltage modules are determined to be in the fourth switch state.

8. The system according to claim 6, characterized in that When the high and low voltage modules are in the first switch state, the first power semiconductor device, the fourth power semiconductor device and the sixth power semiconductor device are turned on, the second power semiconductor device, the third power semiconductor device and the fifth power semiconductor device are turned off, the battery module is disconnected, and the capacitor module is turned on; When the high and low voltage modules are in the second switch state, the first power semiconductor device, the third power semiconductor device and the fifth power semiconductor device are turned on, the second power semiconductor device, the fourth power semiconductor device and the sixth power semiconductor device are turned off, and the battery module and the capacitor module are disconnected; When the high and low voltage modules are in the third switch state, the first power semiconductor device, the third power semiconductor device and the fifth power semiconductor device are turned off, the second power semiconductor device, the fourth power semiconductor device and the sixth power semiconductor device are turned on, and the battery module and the capacitor module are disconnected; When the high and low voltage module is in the fourth switching state, the first power semiconductor device, the fourth power semiconductor device and the sixth power semiconductor device are turned off, the second power semiconductor device, the third power semiconductor device and the fifth power semiconductor device are turned on, the battery module is disconnected, and the capacitor module is turned on.

9. The system according to claim 7, characterized in that When the high and low voltage modules are in the fifth switch state, the first power semiconductor device, the fourth power semiconductor device and the fifth power semiconductor device are turned on, the second power semiconductor device, the third power semiconductor device and the sixth power semiconductor device are turned off, and the battery module and the capacitor module are turned on; When the high and low voltage modules are in the sixth switch state, the first power semiconductor device, the third power semiconductor device and the sixth power semiconductor device are turned on, the second power semiconductor device, the fourth power semiconductor device and the fifth power semiconductor device are turned off, the battery module is turned on, and the capacitor module is disconnected; When the high and low voltage module is in the seventh switch state, the first power semiconductor device, the third power semiconductor device and the sixth power semiconductor device are turned off, the second power semiconductor device, the fourth power semiconductor device and the fifth power semiconductor device are turned on, the battery module is turned on, and the capacitor module is disconnected; When the high and low voltage module is in the eighth switching state, the first power semiconductor device, the fourth power semiconductor device and the fifth power semiconductor device are turned off, the second power semiconductor device, the fourth power semiconductor device and the sixth power semiconductor device are turned on, and the battery module and the capacitor module are turned on.

10. The system according to claim 7, characterized in that In the case where the grid requires active power, the control device determines the switch state of the high and low voltage modules according to the current direction of the grid and the required voltage of the grid; When the active power required by the power grid is positive and the current direction is the first direction, determining that the high and low voltage modules are in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the fifth switching state or the seventh switching state according to the output voltage of the corresponding power link and the required voltage; When the active power required by the power grid is positive and the current direction is the second direction, determining that the high and low voltage modules are in one of the first switch state, the second switch state, the third switch state, the fourth switch state, the sixth switch state or the eighth switch state according to the output voltage of the corresponding power link and the required voltage; When the active power required by the power grid is negative and the current direction is the second direction, determining that the high and low voltage modules are in one of the first switch state, the second switch state, the third switch state, the fourth switch state, the fifth switch state or the seventh switch state according to the output voltage of the corresponding power link and the required voltage; When the active power required by the power grid is negative and the current direction is the first direction, the high and low voltage modules are determined to be in one of the first switching state, the second switching state, the third switching state, the fourth switching state, the sixth switching state or the eighth switching state according to the output voltage of the corresponding power chain link and the required voltage.

11. The system according to claim 5, characterized in that When the current direction is the first direction and the capacitor voltage of the first balancing module is greater than a preset rated voltage, determining that the switch state of the first balancing module is a fourth switch state; When the current direction is the second direction and the capacitor voltage of the first balancing module is greater than a preset rated voltage, determining that the switch state of the first balancing module is the first switch state; When the current direction is the first direction and the capacitor voltage of the first balancing module is less than a preset rated voltage, determining that the switch state of the first balancing module is the first switch state; When the current direction is the second direction and the capacitor voltage of the first balancing module is less than a preset rated voltage, it is determined that the switch state of the first balancing module is the fourth switch state.

12. The system according to claim 5, characterized in that When the current direction is the first direction and the battery power of the second balancing module is greater than a preset power, determining that the switch state of the second balancing module is one of the fifth switch state or the seventh switch state; When the current direction is the first direction and the battery power of the second balancing module is less than a preset power, determining that the switch state of the second balancing module is one of the sixth switch state or the eighth switch state; When the current direction is the second direction and the battery power of the second balancing module is less than a preset power, determining that the switch state of the second balancing module is one of the fifth switch state or the seventh switch state; When the current direction is the second direction and the battery power of the second balancing module is greater than the preset power, it is determined that the switch state of the second balancing module is one of the sixth switch state or the eighth switch state.

13. An electronic device, characterized in that: include: A hybrid static phase condenser system as claimed in any one of claims 1 to 12.

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