Static Var Compensator, Voltage Sag Processing Device and Its Processing Method

Abstract

The present invention relates to a static var compensator, a voltage sag processing device and a processing method thereof. The static var compensator can not only charge and discharge the super capacitor by controlling the H-bridge type switch, but also output a square wave of alternating current voltage at the H-bridge output. The energy transmitted by the buck-boost converter can be controlled by adjusting the duty cycle of the H-bridge on the DC side; the phase shift angle of each power sub-module can also be controlled to control the voltage output by the static var compensator and eliminate harmonics to the greatest extent. Based on the characteristics of the static var compensator, the voltage sag processing device and the processing method thereof realize the power supply switching of the AC bus by controlling the on-off of the first controlled switch and the second controlled switch, and use the main power supply, the standby power supply or the static var compensator as the power supply of the AC bus to ensure the stable power supply of the AC bus to the load carried.

Description

Technical Field

[0001] The present invention relates to the technical field of high - voltage distribution networks, and particularly to a static var compensator, a voltage sag processing device and a processing method thereof. Background Art

[0002] The emergence of more and more high - tech industries and high - value - added industries has put forward higher requirements for power quality. High - quality power parks are effective solutions to regional high - quality power supply problems. Once a short - circuit interruption and sag occur on the feeder of the distribution network, significant economic losses will be caused.

[0003] Based on the topology of dual - loop power supply and the coordinated operation of multiple power quality control devices, it is necessary to control the switching of two thyristors by a solid - state switch to achieve the switching of the main and standby power supplies, so as to solve the problems of voltage drop and interruption. However, the thyristor switching time is relatively long, about 20 ms or so. During this process, the load power supply will be interrupted for a short time, causing losses to sensitive users. The static var compensator based on the interconnection of distribution network feeders can avoid the power supply interruption caused by conventional switch switching operations, and can also alleviate phenomena such as voltage sags and harmonics, and improve the power quality during normal operation. Traditional static var compensators include an H - bridge composed of four IGBTs (Insulated Gate Bipolar Transistors), and a buck - boost converter connected to the rear stage of the H - bridge for connecting the energy storage capacitor C. The buck - boost converter consists of two switches (composed of IGBTs) and an inductor. However, this structure requires more switching tubes, increasing the cost of the static var compensator. Summary of the Invention

[0004] Based on this, it is necessary to provide a static var compensator, a voltage sag processing device and a processing method thereof in view of the deficiencies existing in the structure of traditional static var compensators.

[0005] A static var compensator includes a plurality of cascaded power sub - modules:

[0006] The power sub - module includes:

[0007] An H - bridge composed of four bridge switches;

[0008] A first inductor;

[0009] A second inductor;

[0010] A super capacitor, one end of which is connected to the common terminal of the upper bridge arm of the H - bridge through the first inductor, and the other end of which is connected to the common terminal of the lower bridge arm of the H - bridge through the second inductor;

[0011] Wherein, the common terminal of the lower bridge arm of one power sub - module is connected to the common terminal of the upper bridge arm of the next power sub - module to form a cascaded structure.

[0012] The above static var compensator includes a plurality of cascaded power sub-modules. Each power sub-module includes an H-bridge composed of four bridge switches, a first inductor, a second inductor, and a super capacitor. Among them, the common terminal of the lower bridge arm of one power sub-module is connected to the common terminal of the upper bridge arm of the next power sub-module to form a cascaded structure; one end of the super capacitor is connected to the common terminal of the upper bridge arm of the H-bridge through the first inductor, and the other end is connected to the common terminal of the lower bridge arm of the H-bridge through the second inductor. Based on this, a buck-boost converter is formed by the first inductor and the second inductor, saving the use of switches to reduce costs and improve reliability. At the same time, by controlling the bridge switches of the H-bridge, the charging and discharging of the super capacitor can be realized, and the H-bridge can output a square wave of AC voltage. On the DC side, the energy transmitted by the buck-boost converter can be controlled by adjusting the duty cycle of the H-bridge; the phase shift angle of each power sub-module can also be controlled to control the voltage output by the static var compensator and eliminate harmonics to the greatest extent.

[0013] In one embodiment, the power sub-module further includes:

[0014] A DC link capacitor, one end is connected to the power supply voltage terminal of the H-bridge, and the other end is connected to the ground terminal of the H-bridge.

[0015] In one embodiment, the bridge switch includes an IGBT.

[0016] A voltage sag processing device includes:

[0017] A main power supply, connected to the first feeder;

[0018] A standby power supply, connected to the second feeder;

[0019] A static var compensator, one end is connected to the corresponding phase of the AC bus, and the other end is used for grounding;

[0020] A first controlled switch, one end is connected to the corresponding phase of the first feeder, and the other end is connected to the corresponding phase of the AC bus;

[0021] A second controlled switch; one end is connected to the corresponding phase of the second feeder, and the other end is connected to the corresponding phase of the AC bus.

[0022] The above voltage sag processing device, based on the characteristics of the static var compensator, realizes the power supply switching of the AC bus by controlling the on-off of the first controlled switch and the second controlled switch, using the main power supply, the standby power supply or the static var compensator as the power supply of the AC bus to ensure the stable power supply of the AC bus to the load it drives.

[0023] In one embodiment, the first controlled switch includes a multi-phase first thyristor switch;

[0024] The first thyristor switch includes:

[0025] A set of antiparallel thyristors, one side is used to connect the corresponding phase of the first feeder, and the other side is used to connect the corresponding phase of the AC bus.

[0026] In one embodiment, the second controlled switch includes a multi-phase second thyristor switch;

[0027] The second thyristor switch includes:

[0028] A set of antiparallel thyristors, one side is used to connect the corresponding phase of the second feeder, and the other side is used to connect the corresponding phase of the AC bus.

[0029] In one embodiment, the first thyristor switch or the second thyristor switch further includes:

[0030] A voltage sharing circuit, connected to the antiparallel thyristors.

[0031] In one embodiment, it further includes:

[0032] A connecting reactor;

[0033] Wherein, the static var compensator is connected to the corresponding phase of the AC bus through the connecting reactor.

[0034] A processing method of a voltage sag processing device includes steps:

[0035] Detect the voltage of the first feeder;

[0036] When the voltage is within the normal voltage range, turn on the first controlled switch and turn off the second controlled switch;

[0037] When the voltage is within the abnormal voltage range, turn off the first controlled switch and the second controlled switch.

[0038] The above-mentioned processing method of the voltage sag processing device, based on the characteristics of the static var compensator, realizes the power supply switching of the AC bus through the on-off control of the first controlled switch and the second controlled switch, and uses the main power supply, standby power supply or static var compensator as the power supply of the AC bus to ensure the stable power supply of the AC bus to the load it drives.

[0039] In one embodiment, it further includes steps:

[0040] When the voltage is within the abnormal voltage range and lasts for a preset time, turn off the first controlled switch and turn on the second controlled switch.

[0041] A processing device of a voltage sag processing device includes:

[0042] A voltage detection module, used to detect the voltage of the first feeder;

[0043] The first control module is configured to turn on the first controlled switch and turn off the second controlled switch when the voltage is within the normal voltage range;

[0044] The second control module is configured to turn off the first controlled switch and the second controlled switch when the voltage is within the abnormal voltage range.

[0045] Based on the characteristics of the static var compensator, the processing device of the voltage sag processing device in any of the above embodiments realizes the power supply switching of the AC bus by controlling the on / off of the first controlled switch and the second controlled switch, using the main power supply, the standby power supply or the static var compensator as the power supply of the AC bus, and ensuring the stable power supply of the AC bus to the load it drives.

[0046] A computer storage medium stores computer instructions thereon, and when the computer instructions are executed by a processor, the processing method of the voltage sag processing device in any of the above embodiments is realized.

[0047] Based on the characteristics of the static var compensator, the above computer storage medium realizes the power supply switching of the AC bus by controlling the on / off of the first controlled switch and the second controlled switch, using the main power supply, the standby power supply or the static var compensator as the power supply of the AC bus, and ensuring the stable power supply of the AC bus to the load it drives.

[0048] A computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the processing method of the voltage sag processing device in any of the above embodiments is realized.

[0049] Based on the characteristics of the static var compensator, the above computer device realizes the power supply switching of the AC bus by controlling the on / off of the first controlled switch and the second controlled switch, using the main power supply, the standby power supply or the static var compensator as the power supply of the AC bus, and ensuring the stable power supply of the AC bus to the load it drives. Description of the Drawings

[0050] Figure 1 Schematic diagram of the static var compensator circuit of an embodiment;

[0051] Figure 2 Schematic diagram of the operation of the static var compensator in a specific application example;

[0052] Figure 3 Schematic diagram of the structure of the voltage sag processing device of an embodiment;

[0053] Figure 4 Flowchart of the processing method of the voltage sag processing device of an embodiment;

[0054] Figure 5 Schematic diagram of the operation of the voltage sag processing device in the first process;

[0055] Figure 6 Schematic diagram of the operation of the voltage sag processing device for the second process;

[0056] Figure 7 Schematic diagram of the operation of the voltage sag processing device for the third process;

[0057] Figure 8 Structural diagram of the processing device module of the voltage sag processing device according to an embodiment;

[0058] Figure 9 Schematic diagram of the internal structure of a computer according to an embodiment. Detailed implementation manners

[0059] In order to better understand the object, technical solution and technical effect of the present invention, the present invention will be further described and explained below with reference to the accompanying drawings and embodiments. At the same time, it is stated that the embodiments described below are only used to explain the present invention and are not used to limit the present invention.

[0060] An embodiment of the present invention provides a static var compensator.

[0061] Figure 1 Schematic diagram of the circuit of the static var compensator according to an embodiment, as Figure 1 shown, a static var compensator according to an embodiment includes a plurality of cascaded power sub-modules 1000:

[0062] The power sub-module 1000 includes:

[0063] An H-bridge composed of four bridge switches (1 / 2 / 3 / 4);

[0064] A first inductor L1;

[0065] A second inductor L2;

[0066] A super capacitor Cs, one end of which is connected to the common terminal R1 of the upper bridge arm of the H-bridge through the first inductor L1, and the other end of which is connected to the common terminal R2 of the lower bridge arm of the H-bridge through the second inductor L2;

[0067] Among them, the common terminal R2 of the lower bridge arm of one power sub-module 1000 is connected to the common terminal R1 of the upper bridge arm of the next power sub-module 1000 to form a cascaded structure.

[0068] As Figure 1 shown, four bridge switches form an H-bridge, the AC side of the H-bridge structure is cascaded and output, and the DC side H-bridge switch is connected to the inductor and the super capacitor Cs.

[0069] In the connection between the H-bridge and the super capacitor Cs, a buck-boost converter composed of the first inductor L1 and the second inductor L2 is included, and the super capacitor Cs drives according to the buck-boost converter.

[0070] In one embodiment, the bridge switch includes semiconductor switches such as MOS transistors, triodes, or IGBTs. As a preferred embodiment, the IGBT is selected as the bridge switch. As Figure 1 shown, an H-bridge is formed by four IGBTs, as well as the upper-arm common terminal R1 and the lower-arm common terminal R2.

[0071] In one embodiment, the power sub-module 1000 further includes:

[0072] A DC-link capacitor Cl, one end of which is connected to the power supply voltage terminal VCC of the H-bridge, and the other end is connected to the ground terminal GND of the H-bridge.

[0073] The DC-link capacitor Cl is used to constitute the bidirectional energy flow of the H-bridge switch on the DC side.

[0074] To better explain a static var compensator in one embodiment, a specific application example is used for explanation. Figure 2 It is a schematic diagram of the operation of a static var compensator for a specific application example. As Figure 2 shown, it includes bridge switches 1, 2, 3, and 4. When bridge switches 1 and 3 are turned on, the supercapacitor Cs is in the working state through the second inductor L2, and the DC-link capacitor Cl is in the working state; when bridge switches 2 and 4 are turned on, the supercapacitor Cs is in the working state through the first inductor L1, and the DC-link capacitor Cl is in the working state; when all the bridge switches are turned on, the DC-link capacitor Cl is in the working state.

[0075] The static var compensator in any of the above embodiments includes a plurality of cascaded power sub-modules 1000. Each power sub-module 1000 includes an H-bridge formed by four bridge switches, a first inductor L1, a second inductor L2, and a supercapacitor Cs. Among them, the lower-arm common terminal R2 of one power sub-module 1000 is connected to the upper-arm common terminal R1 of the next power sub-module 1000 to form a cascaded structure; one end of the supercapacitor Cs is connected to the upper-arm common terminal R1 of the H-bridge through the first inductor L1, and the other end is connected to the lower-arm common terminal R2 of the H-bridge through the second inductor L2. Based on this, a buck-boost converter is formed by the first inductor L1 and the second inductor L2, saving the use of switches to reduce costs and improve reliability. At the same time, by controlling the H-bridge switch, both the charging and discharging of the supercapacitor Cs can be realized, and the H-bridge can also output an AC voltage square wave. The energy transmitted by the buck-boost converter can be controlled by adjusting the duty cycle of the H-bridge on the DC side; the voltage output by the static var compensator can also be controlled by controlling the phase-shift angle of each power sub-module 1000, and harmonics can be eliminated to the greatest extent.

[0076] The embodiment of the present invention also provides a voltage sag processing device.

[0077] Figure 3 Schematic diagram of the voltage sag processing device according to an embodiment, as Figure 3 shown, the voltage sag processing device according to an embodiment includes:

[0078] Main power supply S1, connected to the first feeder Line1;

[0079] Standby power supply S2, connected to the second feeder Line2;

[0080] Static var compensator Y1, one end connected to the corresponding phase of the AC bus Line3, and the other end grounded;

[0081] First controlled switch K1, one end connected to the corresponding phase of the first feeder Line1, and the other end connected to the corresponding phase of the AC bus Line3;

[0082] Second controlled switch K2; one end connected to the corresponding phase of the second feeder Line2, and the other end connected to the corresponding phase of the AC bus Line3.

[0083] The main power supply S1 is used to provide AC power supply for the first feeder Line1, and the standby power supply S2 provides AC power supply for the second feeder Line2. For the convenience of explaining this embodiment, taking the first feeder Line1, the second feeder Line2, and the AC bus Line3 as three-phase electricity as an example, the embodiment is explained. It should be noted that the three-phase electricity is related to the number of static var compensators Y1 or the corresponding switches. The three-phase electricity does not represent the only limitation on the number of phases, but only for the convenience of explanation.

[0084] The main power supply S1 transmits the power supply to the AC bus Line3 through the on / off of the first controlled switch K1 to provide power supply for the load on the AC bus Line3. The sensitive load types in the load are sensitive to power quality events such as power supply interruption or voltage sag.

[0085] The standby power supply S2 transmits the power supply to the AC bus Line3 through the on / off of the second controlled switch K2 to provide power supply for the load on the AC bus Line3. The sensitive load types in the load are sensitive to power quality events such as power supply interruption or voltage sag.

[0086] Among them, the static var compensator Y1 corresponds to the phase of the AC bus Line3 one by one. When the main power supply S1 or the standby power supply S2 is incorporated into the AC bus Line3, the AC bus Line3 charges the super capacitor of the static var compensator Y1. When there is no power supply incorporated into the AC bus Line3, the super capacitor of the static var compensator Y1 discharges to supply power to the load carried by the AC bus Line3.

[0087] In one of the embodiments, as Figure 3As shown, it includes a three-phase static var compensator Y1, which is connected in one-to-one correspondence with the phases of the AC bus Line3, so that static var compensators Y1 corresponding to phases A, B, and C of the AC bus Line3 are connected.

[0088] Among them, the first controlled switch K1 and the second controlled switch K2 can both be turned on or off according to an external switch control signal to control the corresponding main power supply S1 or standby power supply S2 to be incorporated into the AC bus Line3.

[0089] In one embodiment, the first controlled switch K1 and the second controlled switch K2 include controllable switch devices or controllable switch modules such as electronic switches, relays, or semiconductor switches.

[0090] As a preferred embodiment, as Figure 3 shown, the first controlled switch K1 includes a multi-phase first thyristor switch D1;

[0091] The first thyristor switch D1 includes:

[0092] A set of antiparallel thyristors Z1, one side is used to connect the corresponding phase of the first feeder Line1, and the other side is used to connect the corresponding phase of the AC bus Line3.

[0093] The external switch control signal is input to the gates of the thyristors in the antiparallel thyristors Z1 to realize the on-off control of the thyristors.

[0094] Similarly, in one embodiment, as Figure 3 shown, the second controlled switch K2 includes a multi-phase second thyristor switch D2;

[0095] The second thyristor switch D2 includes:

[0096] A set of antiparallel thyristors Z1, one side is used to connect the corresponding phase of the second feeder Line2, and the other side is used to connect the corresponding phase of the AC bus Line3.

[0097] In one embodiment, as Figure 3 shown, the first thyristor switch D1 or the second thyristor switch D2 further includes:

[0098] A voltage equalizing circuit J1, which is connected to the antiparallel thyristors Z1.

[0099] Through the resistance voltage division of the voltage equalizing circuit J1, it cooperates with the antiparallel thyristors Z1 to realize the control logic of the external switch control signal and maintain the stability of the on-off logic.

[0100] In one embodiment, as Figure 3 shown, a voltage sag processing device in one embodiment further includes:

[0101] Connect the reactor P1;

[0102] Among them, the static var compensator Y1 is connected to the corresponding phase of the AC bus Line3 through the connecting reactor P1.

[0103] Provide a path between the AC bus Line3 and the static var compensator Y1 through the connecting reactor P1.

[0104] In one embodiment, as Figure 3 shown, the voltage sag processing device of one embodiment further includes:

[0105] Compensator switch H1;

[0106] Among them, the static var compensator Y1 is connected to the corresponding phase of the AC bus Line3 through the compensator switch H1.

[0107] Manage the connection of the static var compensator Y1 to the AC bus Line3 by turning on or off the compensator switch H1. In one embodiment, the compensator switch H1 includes controllable switch devices or controllable switch modules such as electronic switches, relays, or semiconductor switches.

[0108] The voltage sag processing device of any of the above embodiments, based on the characteristics of the static var compensator Y1, realizes the power supply switching of the AC bus Line3 through the on-off control of the first controlled switch K1 and the second controlled switch K2, using the main power supply S1, the standby power supply S2, or the static var compensator Y1 as the power supply of the AC bus Line3 to ensure the stable power supply of the AC bus Line3 to the loads it drives.

[0109] The embodiment of the present invention also provides a processing method for a voltage sag processing device.

[0110] Figure 4 For the flowchart of the processing method of the voltage sag processing device of one embodiment, as Figure 4 shown, the processing method of the voltage sag processing device of one embodiment includes steps S100 to S102:

[0111] S100, detect the voltage of the first feeder Line1;

[0112] S101, when the voltage is within the normal voltage range, turn on the first controlled switch K1 and turn off the second controlled switch K2;

[0113] Among them, the normal voltage range is used to characterize that the voltage of the first feeder Line1 meets the demand range of the load. When the first feeder Line1 is operating normally, the voltage of the first feeder Line1 is within the normal voltage range. It should be noted that the normal voltage range can be determined according to the AC power grid, load, and power supply of the first feeder Line1, and there is no specific defined range.

[0114] S102, when the voltage is within the abnormal voltage range, turn off the first controlled switch K1 and the second controlled switch K2.

[0115] Among them, the abnormal voltage range is used to characterize the voltage fluctuation range of the first feeder Line1 when power quality events such as power supply interruption and voltage sag occur in the first feeder Line1.

[0116] Figure 5 It is a schematic diagram of the working process of the voltage sag processing device for the first process, as Figure 5 shown. When the main power supply S1 is operating normally and the voltage of the first feeder Line1 is within the normal voltage range, the standby power supply S2 is not connected. At this time, the static var compensator Y1 is in the power quality management mode and the grid-connected mode, responsible for providing functions such as power factor compensation and harmonic compensation. The main power supply S1 directly supplies power to the load of the AC bus Line3 through the first controlled switch K1.

[0117] Figure 6 It is a schematic diagram of the working process of the voltage sag processing device for the second process, as Figure 6 shown. When a power supply interruption or voltage sag occurs in the first feeder Line1, the static var compensator Y1 enters the voltage sag processing mode, turns off the first controlled switch K1, disconnects the main power supply S1, and the static var compensator Y1 enters the off-grid mode. It performs voltage sag compensation with the voltage before the abnormality of the first feeder Line1 as the rated value, and uses the super capacitor as a temporary power supply to provide continuous power supply for the load of the AC bus Line3.

[0118] In one embodiment, as Figure 4 shown, the processing method of the voltage sag processing device in one embodiment further includes step S200:

[0119] S200, when the voltage is within the abnormal voltage range and after a preset time, turn off the first controlled switch K1 and turn on the second controlled switch K2.

[0120] Figure 7 It is a schematic diagram of the working process of the voltage sag processing device for the third process, as Figure 7As shown, when the voltage is within the abnormal voltage range and lasts for a preset time, if the voltage of the first feeder Line1 cannot return to normal within the specified time, the static var compensator Y1 collects the voltage signal of the second feeder Line2, controls its output voltage to gradually synchronize with the voltage of the second feeder Line2, and then triggers the second controlled switch K2 to conduct. The standby power supply S2 supplies power to the load through the second feeder Line2 to ensure that the power supply to the load does not interrupt during the whole process.

[0121] After the voltage is within the abnormal voltage range and lasts for a preset time, after the second controlled switch K2 conducts and the standby power supply S2 is put into use, the static var compensator returns to the grid-connected mode, and the super capacitor enters the charging state to prepare for the next entry into the voltage sag processing mode. Based on this, the voltage sag processing is realized.

[0122] The processing method of the voltage sag processing device of any of the above embodiments, based on the characteristics of the static var compensator Y1, realizes the power supply switching of the AC bus Line3 through the on-off control of the first controlled switch K1 and the second controlled switch K2, and uses the main power supply S1, the standby power supply S2 or the static var compensator Y1 as the power supply of the AC bus Line3 to ensure the stable power supply of the AC bus Line3 to the load it drives.

[0123] The embodiment of the present invention also provides a processing device of a voltage sag processing device.

[0124] Figure 8 It is a structural diagram of a processing device module of a voltage sag processing device in an embodiment, as Figure 8 shown, the processing device of the voltage sag processing device in an embodiment includes a voltage detection module, a first control module and a second control module:

[0125] The voltage detection module 100 is used to detect the voltage of the first feeder Line1;

[0126] The first control module 101 is used to conduct the first controlled switch K1 and turn off the second controlled switch K2 when the voltage is within the normal voltage range;

[0127] The second control module 102 is used to turn off the first controlled switch K1 and the second controlled switch K2 when the voltage is within the abnormal voltage range.

[0128] The above-mentioned processing device of the voltage sag processing device realizes the power supply switching of the AC bus Line3 through the on-off control of the first controlled switch K1 and the second controlled switch K2 based on the characteristics of the static var compensator Y1, and uses the main power supply S1, the standby power supply S2 or the static var compensator Y1 as the power supply of the AC bus Line3 to ensure the stable power supply of the AC bus Line3 to the load it drives.

[0129] An embodiment of the present invention also provides a computer storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the processing method of the voltage sag processing device in any of the above embodiments is implemented.

[0130] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it may include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the embodiments provided in the present application may include non-volatile and / or volatile memories. Non-volatile memories may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0131] Alternatively, if the above integrated unit of the present invention is implemented in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present invention, in essence, or the part that contributes to the related technology can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a terminal, or a network device, etc.) to execute all or part of the methods of the embodiments of the present invention. The foregoing storage medium includes: various media such as a removable storage device, RAM, ROM, a magnetic disk, or an optical disc that can store program codes.

[0132] Corresponding to the above computer storage medium, in an embodiment, a computer device is also provided. The computer device includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, the processing method of any one of the voltage sag processing devices in the above embodiments is implemented.

[0133] The computer device may be a terminal, and its internal structure diagram may be as shown in Figure 9 . The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a processing method of a voltage sag processing device. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device may be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the housing of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0134] Based on the characteristics of the static var compensator, the above computer device realizes the power supply switching of the AC bus by controlling the on-off of the first controlled switch and the second controlled switch, and uses the main power supply, the standby power supply, or the static var compensator as the power supply of the AC bus to ensure the stable power supply of the AC bus to the load it drives.

[0135] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0136] The above embodiments only represent several implementation manners of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent should be subject to the appended claims.

Claims

1. A static var compensator, characterized in that, including a plurality of cascaded power sub - modules: The power sub - module includes: an H - bridge composed of four bridge switches; a first inductor; a second inductor; a super - capacitor, one end of which is connected to the common terminal of the upper arm of the H - bridge through the first inductor, and the other end is connected to the common terminal of the lower arm of the H - bridge through the second inductor; wherein, the common terminal of the lower arm of one power sub - module is connected to the common terminal of the upper arm of the next power sub - module to form a cascaded structure; the first inductor and the second inductor form a buck - boost converter, and the buck - boost converter adjusts the transmitted energy based on the duty cycle of the H - bridge; the AC side of the H - bridge is cascaded for output, and the DC side of the H - bridge is connected to the super - capacitor through the buck - boost converter; the power sub - module further includes: a DC - link capacitor, one end of which is connected to the power supply voltage terminal of the H - bridge, and the other end is connected to the ground terminal of the H - bridge; the four bridge switches are respectively bridge switch one, bridge switch two, bridge switch three, and bridge switch four; when bridge switch one and bridge switch three are turned on, the super - capacitor is in the working state through the second inductor, and the DC - link capacitor is in the working state; when bridge switch two and bridge switch four are turned on, the super - capacitor is in the working state through the first inductor, and the DC - link capacitor is in the working state; when all four bridge switches are turned on, the DC - link capacitor is in the working state.

2. The static var compensator according to claim 1, characterized in that, The DC - link capacitor is used to constitute the bidirectional energy flow of the DC - side H - bridge switch.

3. The static var compensator according to claim 1, characterized in that, The bridge switch includes an IGBT.

4. A voltage sag processing device, characterized in that, including: a main power supply, connected to the first feeder; a standby power supply, connected to the second feeder; a static var compensator, one end of which is connected to the corresponding phase of the AC bus, and the other end is used for grounding; a first controlled switch, one end of which is connected to the corresponding phase of the first feeder, and the other end is connected to the corresponding phase of the AC bus; a second controlled switch; one end of which is connected to the corresponding phase of the second feeder, and the other end is connected to the corresponding phase of the AC bus; the static var compensator includes a plurality of cascaded power sub - modules: the power sub - module includes: an H - bridge composed of four bridge switches; a first inductor; a second inductor; a super - capacitor, one end of which is connected to the common terminal of the upper arm of the H - bridge through the first inductor, and the other end is connected to the common terminal of the lower arm of the H - bridge through the second inductor; wherein, the common terminal of the lower arm of one power sub - module is connected to the common terminal of the upper arm of the next power sub - module to form a cascaded structure; the first inductor and the second inductor form a buck - boost converter, and the buck - boost converter adjusts the transmitted energy based on the duty cycle of the H - bridge; the AC side of the H - bridge is cascaded for output, and the DC side of the H - bridge is connected to the super - capacitor through the buck - boost converter; the power sub - module further includes a DC - link capacitor, one end of which is connected to the power supply voltage terminal of the H - bridge, and the other end is connected to the ground terminal of the H - bridge; The four bridge switches are respectively a bridge switch one, a bridge switch two, a bridge switch three and a bridge switch four; when the bridge switch one and the bridge switch three are conducting, the super capacitor is in a working state through the second inductor, and the DC link capacitor is in a working state; when the bridge switch two and the bridge switch four are conducting, the super capacitor is in a working state through the first inductor, and the DC link capacitor is in a working state; when all the four bridge switches are conducting, the DC link capacitor is in a working state.

5. The voltage sag processing device according to claim 4, wherein The first controlled switch includes a multi-phase first thyristor switch. The first thyristor switch includes: A set of antiparallel thyristors, one side is used to connect the corresponding phase of the first feeder, and the other side is used to connect the corresponding phase of the AC bus.

6. The voltage sag processing device according to claim 4, wherein, The second controlled switch includes a multi-phase second thyristor switch. The second thyristor switch includes: A set of antiparallel thyristors, one side is used to connect the corresponding phase of the second feeder, and the other side is used to connect the corresponding phase of the AC bus.

7. The voltage sag processing device according to claim 5 or 6, characterized in that, The first thyristor switch or the second thyristor switch further includes: A voltage equalizing circuit connected to the antiparallel thyristors.

8. The voltage sag processing device according to claim 4, wherein It further includes: A connecting reactor; Wherein, the static var compensator is connected to the corresponding phase of the AC bus through the connecting reactor.

9. A processing method of a voltage sag processing device, characterized in that, It is applied to the voltage sag processing device as described in claim 4; The method includes the steps of: Detect the voltage of the first feeder; When the voltage is within the normal voltage range, turn on the first controlled switch and turn off the second controlled switch; When the voltage is within the abnormal voltage range, turn off the first controlled switch and the second controlled switch, so as to switch the power supply to the AC bus based on the characteristics of the static var compensator to ensure the stable power supply of the AC bus to the loads it drives.

10. The processing method of the voltage sag processing device according to claim 9, characterized in that, It further includes the step of: When the voltage is within the abnormal voltage range and lasts for a preset time, turn off the first controlled switch and turn on the second controlled switch.

Images