Energy release device and control method thereof, overvoltage clamping device

Abstract

The present application provides an energy release device and a control method thereof, and an overvoltage clamping device. The energy release device is connected in parallel at both ends of the overvoltage circuit of the power system, and includes a first release device, a second release device and a phase selection device. One end of the first release device is connected to one end of the second release device to form the first input end of the energy release device; one end of the phase selection device is the second input end of the energy release device, and the other two ends of the phase selection device are respectively connected to the other ends of the first release device and the second release device; the first release device includes at least one power semiconductor silicon stack component branch, and is first triggered to open after an overvoltage fault, and the second release device includes at least one first-level fast trigger switch component branch, which is controlled to open later; or the second release device includes at least one power semiconductor silicon stack component branch, and is first triggered to open after an overvoltage fault, and the first release device includes at least one first-level fast trigger switch component branch, which is controlled to open later.

Description

Technical Field

[0001] The present application relates to the technical field of power electronics and power systems, and in particular to an energy release device and a control method thereof, and an overvoltage clamping device. Background Art

[0002] In many cases of power electronics and power systems, it is necessary to limit temporary overvoltage, that is, to release the energy under fault conditions. In order to protect key power electronics equipment, the energy release device needs to meet two requirements: rapidity and total energy release requirements.

[0003] The existing main solutions for fault energy release are: circuit breaker, discharge gap, trigger gap and semiconductor thyristor valve.

[0004] Ordinary circuit breakers usually use vacuum or sulfur hexafluoride gas to extinguish arcs, which are characterized by large current flow but slow closing time, with a typical closing time of 30ms to 40ms. When using this solution to release fault energy, the protected equipment needs to withstand the overvoltage before closing, which cannot meet the requirements of rapidity.

[0005] The discharge gap is generally composed of two metal bars exposed to the air and separated by a certain gap. When the instantaneous overvoltage strikes, the gap is broken down, avoiding the voltage increase on the protected equipment. The distance between the two metal bars of this discharge gap can be adjusted as needed, and the structure is relatively simple. Its disadvantages are poor arc extinguishing performance and poor control accuracy.

[0006] The vacuum trigger gap is composed of a vacuum sealed shell, an anode, a cathode and a trigger electrode. The vacuum gap between the anode and the cathode is called the main gap, and the gap filled with a medium between the trigger electrode and the cathode is called the trigger gap. When the vacuum trigger gap is in an isolated high-voltage working state, if an appropriate pulse is applied to the trigger electrode, the trigger gap will produce a flash breakdown along the surface of the medium, resulting in current discharge, and then a high-density metal vapor plasma is generated in the trigger gap, which is quickly injected into the high-voltage main gap to establish a glow discharge. This device has been used in some special equipment, but the trigger gap has high requirements for the internal medium, is difficult to prepare, and has poor control consistency.

[0007] Semiconductor thyristors are widely used in DC transmission and can be used as instantaneous energy release devices. They can be turned on within 2us to limit overvoltage. However, the thyristor cannot withstand the fault current for too long, generally no more than 20ms, and the current peak value cannot exceed 60kA.

[0008] In UHV power transmission systems, when overvoltage occurs on the busbar, lightning arresters are usually required to protect key equipment such as converter valves. In order to accurately control the action time or action voltage of the lightning arrester and avoid overvoltage damage to the converter valve equipment, how to design an energy release device that can be put into operation within 10us and can meet transient energy of 100kA or more has become a difficult problem. Summary of the invention

[0009] An embodiment of the present application provides an energy release device, which is connected in parallel at both ends of an overvoltage circuit of an electric power system, and the energy release device includes a first release device, a second release device and a phase selection device, wherein one end of the first release device is connected to one end of the second release device to form a first input end of the energy release device; one end of the phase selection device is the second input end of the energy release device, and the other two ends of the phase selection device are respectively connected to the other end of the first release device and the other end of the second release device; the first release device includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs, and the second release device includes at least one first-level fast-triggering switch component branch, and is controlled to be opened subsequently; or the second release device includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs, and the first release device includes at least one first-level fast-triggering switch component branch, and is controlled to be opened subsequently.

[0010] According to some embodiments, when at least two of the power semiconductor silicon stack component branches are connected in parallel, each of the power semiconductor silicon stack component branches is connected in series with an inductor.

[0011] According to some embodiments, when at least two of the fast trigger switch components are connected in parallel, each of the fast trigger switch components is connected in series with an inductor.

[0012] According to some embodiments, the power semiconductor silicon stack component branch includes: at least one power semiconductor single stage.

[0013] According to some embodiments, the single-stage power semiconductor includes a thyristor, a trigger unit, a damping circuit and a voltage-equalizing resistor connected in parallel, the damping circuit includes a damping resistor and a damping capacitor connected in series, and one end where the damping resistor and the damping capacitor are connected is also connected to the trigger unit.

[0014] According to some embodiments, the single-stage power semiconductor includes a commutation thyristor, an integrated gate trigger unit, a damping circuit and a voltage-equalizing resistor connected in parallel, the damping circuit includes a damping resistor and a damping capacitor connected in series, and one end where the damping resistor and the damping capacitor are connected is also connected to the integrated gate trigger unit.

[0015] According to some embodiments, the single-stage power semiconductor includes a first thyristor, a first trigger unit, a damping circuit, a voltage equalizing resistor, a second thyristor, and a second trigger unit connected in parallel, the first trigger unit controls the triggering of the first thyristor, the second trigger unit controls the triggering of the second thyristor, the first trigger unit is connected to the second trigger unit, the anode of the first thyristor is connected to the cathode of the second thyristor, the cathode of the first thyristor is connected to the anode of the second thyristor, and the damping circuit includes a damping resistor and a damping capacitor connected in series.

[0016] According to some embodiments, the single-stage power semiconductor includes a first commutating thyristor, a first integrated gate trigger unit, a damping circuit, a voltage equalizing resistor, a second commutating thyristor and a second integrated gate trigger unit connected in parallel, the first integrated gate trigger unit controls the triggering of the first commutating thyristor, the second integrated gate trigger unit controls the triggering of the second commutating thyristor, the anode of the first commutating thyristor is connected to the cathode of the second commutating thyristor, the first integrated gate trigger unit is connected to the second integrated gate trigger unit, the cathode of the first commutating thyristor is connected to the anode of the second commutating thyristor, and the damping circuit includes a damping resistor and a damping capacitor connected in series.

[0017] According to some embodiments, the fast trigger switch assembly branch includes: at least one level of fast trigger switch.

[0018] According to some embodiments, the phase selection device includes a saturated reactor, an inductor, a first fast trigger switch, a second fast trigger switch and a third fast trigger switch, one end of the first fast trigger switch is connected to one end of the saturated reactor to form a first connection end of the phase selection device, and the first connection end of the phase selection device is connected to one end of the first energy release device; one end of the second fast trigger switch is connected to one end of the inductor to form a second connection end of the phase selection device, and the second connection end of the phase selection device is connected to one end of the second energy release device; one end of the third fast trigger switch is connected to the other end of the first fast trigger switch and the other end of the second fast trigger switch, and the other end of the third fast trigger switch is connected to the other end of the saturated reactor and the other end of the inductor to form the third connection end of the phase selection device.

[0019] An embodiment of the present application also provides a control method for the energy release device as described above, including: controlling the phase selection device to quickly trigger the first fast trigger switch, the second fast trigger switch, and the third fast trigger switch of the phase selection device to open; receiving an overvoltage protection instruction, and triggering the opening of the first release device; triggering the opening of the second release device; receiving an overvoltage protection end instruction, and when detecting that the current flowing through the first release device and the second release device is zero, triggering the shutdown of the second release device.

[0020] According to some embodiments, after triggering and opening the second release device, the method further includes: triggering and opening the first fast trigger switch and the second fast trigger switch.

[0021] An embodiment of the present application also provides a control method for the energy release device as described above, including: controlling the phase selection device to quickly trigger the first fast trigger switch, the second fast trigger switch, and the third fast trigger switch of the phase selection device to open; receiving an overvoltage protection instruction, and triggering the opening of the first release device; triggering the opening of the second release device, and triggering the opening of the first fast trigger switch and the second fast trigger switch; detecting that the current of the first release device is less than a fixed value, triggering the shutdown of the first release device; receiving an overvoltage protection end instruction, and when detecting that the current flowing through the second release device is zero, triggering the shutdown of the second release device.

[0022] The embodiment of the present application also provides an overvoltage clamping device, including an energy release device, a damping network, a high-voltage end lightning arrester assembly and a low-voltage end lightning arrester assembly, the damping network includes at least a damping resistor, a damping capacitor, and a voltage-equalizing resistor, the damping resistor is connected in series with the damping capacitor and then connected in parallel with the voltage-equalizing resistor; one end of the high-voltage end lightning arrester assembly is connected to one end of the damping network to form a high-voltage input end of the overvoltage clamping device, and the high-voltage end lightning arrester assembly includes a plurality of lightning arresters connected in series and parallel; one end of the low-voltage end lightning arrester assembly is connected to one end of the energy release device, the other end of the damping network, and the other end of the high-voltage end lightning arrester assembly, and the other end of the low-voltage end lightning arrester assembly is connected to the other end of the energy release device to form a low-voltage input end of the overvoltage clamping device, and the low-voltage end lightning arrester assembly includes a plurality of lightning arresters connected in series and parallel.

[0023] The technical solution provided in the embodiment of the present application utilizes the above-mentioned energy release device and control method to achieve precise control of the action time and action voltage of the energy release device, control the input within 10us, and meet the transient energy release of 100 kA and above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained like these drawings without paying any creative work.

[0025] Figure 1 This is a schematic diagram of a hybrid switch in the prior art.

[0026] Figure 2A This is a schematic diagram of a hybrid control switch in the prior art.

[0027] Figure 2B This is another schematic diagram of a hybrid control switch in the prior art.

[0028] Figure 3A A schematic diagram of an energy release device provided in an embodiment of the present application.

[0029] Figure 3B A schematic diagram of another energy release device provided in an embodiment of the present application.

[0030] Figure 4 This is one of the schematic diagrams of the first release device provided in an embodiment of the present application.

[0031] Figure 5 This is the second schematic diagram of the first release device provided in the embodiment of the present application.

[0032] Figure 6 This is a third schematic diagram of the first release device provided in an embodiment of the present application.

[0033] Figure 7 This is the fourth schematic diagram of the first release device provided in an embodiment of the present application.

[0034] Figure 8 Schematic diagram of the second release device provided in an embodiment of the present application.

[0035] Fig. 9 A schematic diagram of a phase selection device provided in an embodiment of the present application.

[0036] Fig.10 This is one of the schematic diagrams of an example of an energy release device provided in an embodiment of the present application.

[0037] Fig.11A One of the flow charts of a control method based on the above-mentioned energy release device provided in an embodiment of the present application.

[0038] Fig. 11B for Fig.11A Current and control pulse waveform of the control method.

[0039] Fig. 12A The present invention provides a second flow chart of a control method based on the above-mentioned energy release device in an embodiment of the present application.

[0040] Fig. 12B for Fig. 12A Current and control pulse waveform of the control method.

[0041] Fig.13 This is a second schematic diagram of an example of an energy release device provided in an embodiment of the present application.

[0042] Fig.14 for Fig.13 Schematic diagram of the control method flow of the energy release device.

[0043] Fig.15 A schematic diagram of an overvoltage clamping device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0045] It should be understood that the terms "first", "second", etc. in the claims, specification and drawings of the present application are used to distinguish different objects rather than to describe a specific order. The terms "include" and "comprise" used in the specification and claims of the present application indicate the presence of the described features, wholes, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections.

[0046] Figure 1 This is a schematic diagram of a hybrid switch in the prior art.

[0047] like Figure 1 As shown, the hybrid switch 1000 includes a thyristor valve switch 111 connected in series and a mechanical switch 112. The thyristor valve switch 111 includes a single thyristor device 1111 or a plurality of thyristor devices 1111 connected in series. The mechanical switch 112 is a vacuum or SF6 mechanical switch.

[0048] The inventor of the present application has found that when a hybrid switch of this structure is used, the thyristor device 1111 therein is prone to damage and failure. According to the order of switching on two different types of switches, the hybrid switch 1000 has two switching-on modes. The specific analysis is as follows.

[0049] First, the thyristor switch 111 is switched on, and then the mechanical switch 112 is switched on. The start time of the protection fault depends on the speed of the mechanical switch that is switched on last. Due to the current limit speed of the mechanical switch, it cannot be guaranteed that the protection will be switched on within the time of us level, and the protected equipment is at risk.

[0050] Secondly, the mechanical switch 112 is switched on first, and then the thyristor switch 111 is switched on. To ensure the timeliness of the protection startup, it is hoped that the mechanical switch 112 is always in the closed state before the fault occurs. After the fault occurs, the thyristor switch 111 is triggered to open immediately, and the current flowing through the thyristor switch 111 will rise rapidly. Usually, the overvoltage of the protected equipment can be equivalent to a certain capacitive energy. At the moment of starting the protection, the current rise rate can be equivalent to infinity.

[0051] The second working mode can ensure timeliness, but because the gate current injection of the thyristor device requires a process of lateral diffusion from the center of the chip to the edge of the chip inside the thyristor chip, the semiconductor device such as the thyristor is extremely sensitive to the current rise rate when it is just turned on. According to the parameters of the current mainstream manufacturers, a 6-inch thyristor will be damaged if the current rise rate is greater than 600A / us when it is just turned on. It is usually hoped that the current rise rate at this stage can be controlled within 100A / us. After about 5us, the thyristor's ability to withstand the current rise rate will be greatly increased, and the rise rate can reach 3500A / us.

[0052] Figure 2A This is a schematic diagram of a hybrid control switch in the prior art.

[0053] like Figure 2A As shown, the hybrid control switch 2001 includes an inductor 211, a power electronic switch 212 and a bypass circuit breaker 214. The inductor 211 is connected in series with the power electronic switch 212 and then grounded, and the bypass circuit breaker 214 is connected in parallel with the power electronic switch 212.

[0054] Before receiving the impulse voltage, the power electronic switch 212 is in the off state and the bypass circuit breaker 214 is in the off state. After receiving the impulse voltage, the power electronic switch 212 is closed, and the fault current flows through the inductor 211 and the power electronic switch 212. After a period of time, the bypass circuit breaker 214 is closed, and the power electronic switch 212 and the bypass circuit breaker 214 form a parallel branch. After another period of time, the trigger pulse of the power electronic switch 212 stops, and the power electronic switch 212 is converted from the closed state to the open state, and the current flows through the inductor 211 and the bypass circuit breaker 214.

[0055] The inventors of the present application have discovered that when a hybrid control switch of this structure is used, the power electronic switch 212 therein must be a fully controllable device that can be controlled to be turned on and off. Currently, there is no fully controllable semiconductor device that can withstand transients that reach and exceed an impact current of 100kA.

[0056] At the same time, this solution adds the inductor 211 to limit the current rise rate when the power electronic switch 212 is turned on. During the entire current flow process, the inductor 211 is always turned on, the current rise rate is slow, and the overvoltage suppression effect is limited.

[0057] The inventors of the present application also discovered that the bypass circuit breaker 214 used in this solution is usually a mechanical circuit breaker with SF6 inside, and its current closing time is between 40 and 60 ms. Therefore, this solution requires the power electronic switch 212 to withstand overcurrent for a relatively long time, which cannot be met by current fully controlled power semiconductor devices.

[0058] Figure 2B This is another schematic diagram of a hybrid control switch in the prior art.

[0059] like Figure 2B As shown, the hybrid control switch 2002 includes an inductor 211, a power electronic switch 212, a vacuum switch 213 and a bypass circuit breaker 214. The inductor 211 is connected in series with the power electronic switch 212, which is then connected in series with the vacuum circuit breaker 213 and then grounded. The bypass circuit breaker 214 is connected in parallel with the branch after the power electronic switch 212 is connected in series with the vacuum circuit breaker.

[0060] Before being subjected to the impulse voltage, the power electronic switch 212 is in the open state, the bypass circuit breaker 214 is in the open state, and the vacuum circuit breaker 213 is in the closed state. After being subjected to the impulse voltage, the power electronic switch 212 is closed, and the fault current flows through the inductor 211, the power electronic switch 212, and the vacuum circuit breaker 213. After a period of time, the bypass circuit breaker 214 is closed, and the current flows through the inductor 211 and the parallel branch of the power electronic switch 212 and the vacuum circuit breaker 213 and the parallel branch of the bypass circuit breaker 214. After another period of time, the vacuum circuit breaker 213 is disconnected, the power electronic switch 212 is converted from the closed state to the open state, and the current flows through the bypass circuit breaker 214.

[0061] The inventor of the present application has discovered that when a hybrid control switch of this structure is used, the power electronic switch 212 therein is a half-controlled device, generally a thyristor.

[0062] The first problem with this approach is Figure 2AThe scheme is similar to: this increases the inductor 211 to limit the current rise rate at the moment the power electronic switch 212 is turned on. During the entire current-carrying process, the inductor 211 is always turned on, the current rise rate is slow, and the overvoltage suppression effect is limited.

[0063] Figure 3A A schematic diagram of an energy release device provided in an embodiment of the present application.

[0064] like Figure 3A As shown, the energy release device includes a first release device 311, a second release device 312 and a phase selection device 313. One end of the first release device 311 is connected to one end of the second release device 312 to form a first input terminal A of the energy release device 3000. One end of the phase selection device 313 is a second input terminal B of the energy release device 3000, and the other two terminals of the phase selection device 313 are respectively connected to the other end of the first release device 311 and the other end of the second release device 312.

[0065] It is easy to find that the phase selection device 313 can also be connected to the upper ends of the first release device 311 and the second release device 312 to form Figure 3B Schematic diagram of another energy release device.

[0066] The main idea of ​​this application is that if the first release device 311 adopts a branch composed of semiconductor power devices, it will be controlled to be triggered and opened first after an overvoltage fault occurs. On this basis, the second release device 312 will adopt a branch composed of a fast trigger switch to control the second release device 312 to be opened later and bear the main overvoltage release energy. The phase selection device 313 mainly realizes the control of the current rise rate during the energy release process and the distribution in the two branches, mainly including the following two circuits.

[0067] The first release device 311 includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs. The second release device 312 includes at least one level of fast trigger switch component, and is controlled to be opened subsequently to withstand the main overvoltage release energy.

[0068] The second release device 312 includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs. The first release device 311 includes at least one level of fast trigger switch component, and is controlled to be opened subsequently to withstand the main overvoltage release energy.

[0069] Figure 4 This is one of the schematic diagrams of the first release device provided in an embodiment of the present application.

[0070] The first releasing device 4000 includes at least one power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one power semiconductor single stage.

[0071] The power semiconductor single stage 411 includes a thyristor 4111, a trigger unit 4112, a damping circuit and a voltage-equalizing resistor 4114 connected in parallel. The damping circuit includes a damping resistor 4113 and a damping capacitor 4115 connected in series. One end where the damping resistor 4113 and the damping capacitor 4115 are connected is also connected to the trigger unit 4112, and the trigger unit 4112 obtains energy from the damping circuit.

[0072] Optionally, more series-connected stages such as power semiconductor single stage 412 and power semiconductor single stage 413 may be added according to overvoltage requirements.

[0073] Optionally, according to the requirement of the flowing current, the number of parallel branches can be increased, such as: connecting the power semiconductor silicon stack component branch 400 in parallel with another power semiconductor silicon stack component branch 401 .

[0074] Optionally, when at least two power semiconductor silicon stack component branches are connected in parallel, each branch is connected in series with an inductor, such as power semiconductor silicon stack component branch 400 is connected in series with inductor 402, and power semiconductor silicon stack component branch 401 is connected in series with inductor 403, and the two branches are connected in parallel to form a first energy release device 4000.

[0075] Before an overvoltage fault occurs, all thyristors 4111 in the first energy release device 4000 are in a locked-off state. The first energy release device 4000 can withstand very high voltages. Due to the effects of the damping resistor 4113, the damping capacitor 4115 and the equalizing resistor 4114, the system voltage is evenly distributed among each stage of the series-connected power semiconductor single stage 411 during the lockout time.

[0076] After an overvoltage fault occurs, the overvoltage energy needs to be released. All thyristors 4111 in the first energy release device 4000 are triggered and opened at the same time, and a surge current flows through each branch instantly. Due to the action of inductor 402 and inductor 403, the fault current is evenly distributed between the power semiconductor silicon stack component branch 400 and another power semiconductor silicon stack component branch 401.

[0077] Figure 5 This is a schematic diagram of another embodiment of the first releasing device proposed in this application.

[0078] The first releasing device 5000 includes at least one power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one power semiconductor single stage.

[0079] The power semiconductor single stage 511 includes a commutated thyristor GCT (Gate-Commutated Thyristor) 5111, an integrated gate trigger unit 5112, a damping circuit and a voltage-equalizing resistor 5114. The damping circuit includes a damping resistor 5113 and a damping capacitor 5115 connected in series. One end where the damping resistor 5113 and the damping capacitor 5115 are connected is also connected to the integrated gate trigger unit 5112.

[0080] Optionally, according to the overvoltage requirement, more series-connected stages may be added, such as a power semiconductor single stage 512 and a power semiconductor single stage 513 .

[0081] Optionally, according to the requirement of the flowing current, the number of parallel branches can be increased, such as: connecting the power semiconductor silicon stack component branch 500 in parallel with another power semiconductor silicon stack component branch 501 .

[0082] Optionally, when at least two power semiconductor silicon stack component branches are connected in parallel, each branch is connected in series with an inductor, such as semiconductor silicon stack component branch 500 is connected in series with inductor 502, and semiconductor silicon stack component branch 501 is connected in series with inductor 503, and the two branches are connected in parallel to form a first energy release device 5000.

[0083] Before an overvoltage fault occurs, all the commutating thyristors 5111 in the first energy release device 5000 are in a locked off state. The first energy release device 5000 can withstand very high voltages. Due to the effects of the damping resistor 5113, the damping capacitor 5115 and the equalizing resistor 5114, the system voltage is evenly distributed among each stage of the series-connected power semiconductors during the lockout time.

[0084] After an overvoltage fault occurs, the overvoltage energy needs to be released. All the commutating thyristors 5111 in the first energy release device 5000 are triggered and opened at the same time, and a surge current flows through each branch instantly. Due to the action of inductor 502 and inductor 503, the fault current is evenly distributed between the power semiconductor silicon stack component branch 500 and another power semiconductor silicon stack component branch 501.

[0085] The first energy release device 5000 can also be controlled to be turned off. After the trigger pulse of the integrated gate trigger unit is turned off, the current flowing through the commutation thyristor 5111 is rapidly reduced.

[0086] Figure 6 This is a third schematic diagram of the first release device provided in an embodiment of the present application.

[0087] like Figure 6 As shown, the first releasing device 6000 includes at least one power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one power semiconductor single stage.

[0088] The power semiconductor single stage 611 includes a first thyristor 6110, a first trigger unit 6109, a damping circuit, a voltage equalizing resistor 6114, a second thyristor 6111, and a second trigger unit 6112 connected in parallel. The first trigger unit 6109 controls the triggering of the first thyristor 6110, and the second trigger unit 6112 controls the triggering of the second thyristor 6111. The first trigger unit 6109 is connected to the second trigger unit 6112. The anode of the first thyristor 6110 is connected to the cathode of the second thyristor 6111, and the cathode of the first thyristor 6110 is connected to the anode of the second thyristor 6111. The damping circuit includes a damping resistor 6113 and a damping capacitor 6115 connected in series. The anode of the first thyristor 6110 is connected to the cathode of the second thyristor 6111, and the cathode of the first thyristor 6110 is connected to the anode of the second thyristor 6111.

[0089] Optionally, according to the overvoltage requirement, more series-connected stages may be added, such as a power semiconductor single stage 612 and a power semiconductor single stage 613 .

[0090] Optionally, according to the requirement of the flowing current, the number of parallel branches can be increased, such as: connecting the power semiconductor silicon stack component branch 600 in parallel with another power semiconductor silicon stack component branch 601 .

[0091] Optionally, when at least two power semiconductor silicon stack component branches are connected in parallel, each branch is connected in series with an inductor, such as semiconductor silicon stack component branch 600 is connected in series with inductor 602, and semiconductor silicon stack component branch 601 is connected in series with inductor 603, and the two branches are connected in parallel to form a first energy release device 6000.

[0092] Before an overvoltage fault occurs, all the second thyristors 6111 in the first energy release device 6000 and the anti-parallel first thyristor 6110 are in a locked off state. The first energy release device 6000 can withstand very high voltages. Due to the effects of the damping resistor 6113, the damping capacitor 6115 and the equalizing resistor 6114, the system voltage is evenly distributed between each stage of the series power semiconductor single stage 611 during the lockout time.

[0093] After an overvoltage fault occurs, the overvoltage energy needs to be released. All the second thyristors 6111 in the first energy release device 6000 are triggered and turned on at the same time. A surge current flows through each branch instantly. Due to the action of inductor 602 and inductor 603, the fault current is evenly distributed between the power semiconductor silicon stack component branch 600 and another power semiconductor silicon stack component branch 601.

[0094] Figure 7 This is the fourth schematic diagram of the first release device provided in an embodiment of the present application.

[0095] The first releasing device 7000 includes at least one power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one power semiconductor single stage.

[0096] The power semiconductor single stage 711 includes a first commutated thyristor GCT (Gate-Commutated Thyristor) 7110 and a first integrated gate trigger unit 7109 for controlling the first commutated thyristor 7110, a second commutated thyristor GCT 7111 and an integrated gate trigger unit trigger unit 7112 for controlling the second commutated thyristor 7111, a damping circuit and a voltage-equalizing resistor 7114. The damping circuit includes a damping resistor 7113 and a damping capacitor 7115 connected in series. The anode of the first commutated thyristor 7110 is connected to the cathode of the second commutated thyristor 7111, and the cathode of the first commutated thyristor 7110 is connected to the anode of the second commutated thyristor 7111.

[0097] Optionally, according to the overvoltage requirement, more series-connected stages may be added, such as a power semiconductor single stage 712 and a power semiconductor single stage 713 .

[0098] Optionally, according to the requirement of the flowing current, the number of parallel branches can be increased, such as: connecting the power semiconductor silicon stack component branch 700 in parallel with another power semiconductor silicon stack component branch 701 .

[0099] Optionally, when at least two power semiconductor silicon stack component branches are connected in parallel, each branch is connected in series with an inductor, such as power semiconductor silicon stack component branch 700 is connected in series with inductor 702, and power semiconductor silicon stack component branch 701 is connected in series with inductor 703, and the two branches are connected in parallel to form a first energy release device 7000.

[0100] Before an overvoltage fault occurs, all the second commutation thyristors 7111 and the anti-parallel first commutation thyristors 7110 in the first energy release device 7000 are in a locked off state. The first energy release device 7000 can withstand very high voltages. Due to the effects of the damping resistor 7113, the damping capacitor 7115 and the equalizing resistor 7114, the system voltage is evenly distributed between each stage of the series power semiconductor single stage 711 during the lockout time.

[0101] After an overvoltage fault occurs, the overvoltage energy needs to be released. All the second commutation thyristors 7111 in the first energy release device 7000 are triggered and opened at the same time. A surge current flows through each branch instantly. Due to the action of inductor 702 and inductor 703, the fault current is evenly distributed between the power semiconductor silicon stack component branch 700 and another power semiconductor silicon stack component branch 701.

[0102] Figure 8 Schematic diagram of the second release device provided in an embodiment of the present application.

[0103] The second energy release device 8000 includes at least one fast trigger switch component branch, and the fast trigger switch component branch includes at least one level of fast trigger switch 811.

[0104] Optionally, according to the overvoltage requirement, more series stages may be added, such as: fast trigger switch 811, fast trigger switch 812 and fast trigger switch 813 are connected in series.

[0105] Furthermore, the pulses for controlling the fast triggering switches are the same, that is, the closing or opening of the switches is controlled simultaneously.

[0106] Optionally, according to the requirement of the flowing current, the number of branches connected in parallel can be increased, such as a fast trigger switch component branch 800 connected in parallel with another fast trigger switch component branch 801 .

[0107] Optionally, when at least two fast trigger switch component branches are connected in parallel, each branch is connected in series with an inductor, such as fast trigger switch component branch 800 is connected in series with inductor 802, and fast trigger switch component branch 801 is connected in series with inductor 803, and the two branches are connected in parallel to form a second energy release device 8000.

[0108] From the perspective of system design, it is necessary to use a series-parallel combination of fast trigger switches 811. This is because in situations where high reliability is required, if a single fast trigger switch 811 malfunctions, refuses to operate, or the break working voltage is abnormal, multiple fast trigger switch networks will greatly improve the availability and reliability of the system.

[0109] Fig. 9 A schematic diagram of a phase selection device provided in an embodiment of the present application.

[0110] like Fig. 9 As shown, the phase selection device 9000 internally includes a saturated reactor 911, an inductor 912, a first fast trigger switch 913, a second fast trigger switch 914, and a third fast trigger switch 915.

[0111] One end of the first fast trigger switch 913 is connected to one end of the saturated reactor 911 to form a first connection end of the phase selection device, and the first connection end of the phase selection device is connected to one end of the first energy release device. One end of the second fast trigger switch 914 is connected to one end of the inductor 912 to form a second connection end of the phase selection device, and the second connection end of the phase selection device is connected to one end of the second energy release device.

[0112] One end of the third fast trigger switch 915 is connected to the other end of the first fast trigger switch 913 and the other end of the second fast trigger switch 914, and the other end of the third fast trigger switch 915 is connected to the other end of the saturated inductor 911 and the other end of the inductor 912 to form the third connection end of the phase selection device, which is finally a connection terminal of the energy release device.

[0113] Optionally, the inductor 912 may also be a saturable reactor.

[0114] The main function of the phase selection device is to set the current sharing ratio between the first release device and the second release device. At the same time, the first fast trigger switch 913, the second fast trigger switch 914 and the third fast trigger switch 915 form a T-type network. The connection mode between the two saturated reactances in the phase selection device 9000 and the first release device and the second release device is selected by flexibly configuring the closing state position.

[0115] Fig.10 A schematic diagram of an example of an energy release device provided in an embodiment of the present application.

[0116] like Fig.10 As shown, the first release device 1011 includes a power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one stage of power semiconductor single stage 10111 connected in series. The second release device 1012 includes a first stage fast trigger switch 10112, and the phase selection device 1013 includes a saturated reactor 10114, an inductor 10115, a first fast trigger switch 10116, a second fast trigger switch 10117, and a third fast trigger switch 10118.

[0117] One end of the first release device 1011 is connected to one end of the second release device 1012 to form a first input end of the energy release device 10000. One end of the phase selection device 1013 is the second input end of the energy release device 10000, and the other two ends of the phase selection device 1013 are connected to the other end of the first release device 1011 and the other end of the second release device 1012 respectively.

[0118] Furthermore, the position of the quick trigger switch of the phase selection device is set. If the first quick trigger switch 10116, the second quick trigger switch 10117, and the third quick trigger switch 10118 are all selected to be opened, that is, the first release device 1011 and the saturated inductor 10114 are connected in series to form a first branch, and the quick trigger switch 10112 and the inductor 10115 are connected in series to form a second branch.

[0119] Furthermore, the order in which the first fast trigger switch 10116, the second fast trigger switch 10117, and the third fast trigger switch 10118 are closed can be flexibly set according to the order in which the first release device 1011 and the second release device 1012 are put into operation, so as to control the distribution of the fault current between the first release device 1011 and the second release device 1012.

[0120] Fig.11A One of the flow charts of a control method based on the above-mentioned energy release device provided in an embodiment of the present application, the energy release device is connected in parallel to both ends of the overvoltage circuit.

[0121] In S1111, the phase selection device is controlled to quickly trigger the switch state, the first fast trigger switch 10116 is opened, the second fast trigger switch 10117 is opened, and the third fast trigger switch 10118 is opened.

[0122] In S1112, an overvoltage protection instruction is received, and the first release device is triggered to be turned on.

[0123] In S1113 , the second release device is triggered to be turned on.

[0124] In S1114, an overvoltage protection end instruction is received, and when it is detected that the current flowing through the first release device and the second release device is zero, the second release device is triggered to be turned off. Then, the energy release device is set to a hot standby state.

[0125] Fig. 11B for Fig.11A Current and control pulse waveform of the control method.

[0126] like Fig. 11B As shown, CH1 is the total current of the energy release device, CH2 is the current of the first release device, CH3 is the current of the second release device, CH4 is the first release device pulse, CH5 is the second release device pulse, CH6 is the first fast trigger switch 10116 pulse, CH7 is the second fast trigger switch 10117 pulse, and CH8 is the third fast trigger switch 10118 pulse.

[0127] At 200ms, the first release device is controlled to be opened. The current rise rate of the first release device is not high within the initial 2us. After 2us, when the current reaches more than 500A, the current rises rapidly. After a delay of 5ms, the second release device is controlled to be opened, and the current of the second release device begins to rise. The total current peak of the energy release device reaches 120kA. At 280ms, the current drops to zero and the work is completed.

[0128] Fig. 12AThe second flow chart of a control method based on the above-mentioned energy release device provided in an embodiment of the present application, wherein the energy release device is connected in parallel to both ends of the overvoltage circuit.

[0129] In S1211, the phase selection device is controlled to quickly trigger the switch state, the first fast trigger switch 10116 is opened, the second fast trigger switch 10117 is opened, and the third fast trigger switch 10118 is opened.

[0130] In S1212, an overvoltage protection instruction is received, and the first release device is triggered to be turned on.

[0131] In S1213 , the second release device is triggered to be turned on, and the first rapid trigger switch 10116 and the second rapid trigger switch 10117 are triggered to be turned on.

[0132] In S1214, an overvoltage protection end instruction is received, and when it is detected that the current flowing through the first release device and the second release device is zero, the second release device is triggered to be turned off. Then, the energy release device is set to a hot standby state.

[0133] Fig. 12B for Fig. 12A Current and control pulse waveform of the control method.

[0134] like Fig. 12B As shown, CH1 is the total current of the energy release device, CH2 is the current of the first release device, CH3 is the current of the second release device, CH4 is the first release device pulse, CH5 is the second release device pulse, CH6 is the first fast trigger switch 10116 pulse, CH7 is the second fast trigger switch 10117 pulse, and CH8 is the third fast trigger switch 10118 pulse.

[0135] At 200ms, the first release device is controlled to be opened. The current rise rate of the first release device is not high within the initial 2us. After 2us, when the current reaches more than 500A, the current rises rapidly. After a delay of 5ms, the second release device is controlled to be opened, and the first quick trigger switch 10116 and the second quick trigger switch 10117 are triggered to open. The current of the second release device begins to rise rapidly, and the current of the first release device decreases rapidly. The total current peak of the energy release device reaches 120kA. At 280ms, the current drops to zero and the work is completed.

[0136] Fig.13 This is a second schematic diagram of an example of an energy release device provided in an embodiment of the present application.

[0137] like Fig.13As shown, the first release device 1311 includes at least one power semiconductor silicon stack component branch, and the power semiconductor silicon stack component branch includes at least one stage of power semiconductor single stage 13111 connected in series. The second release device 1312 includes a first stage fast trigger switch 13112. The phase selection device 1313 includes a saturated reactor 13114, an inductor 13115, a first fast trigger switch 13116, a second fast trigger switch 13117, and a third fast trigger switch 13118.

[0138] One end of the first release device 1311 is connected to one end of the second release device 1312 to form a first input end of the energy release device 13000. One end of the phase selection device 1313 is the second input end of the energy release device 13000, and the other two ends of the phase selection device 1313 are connected to the other end of the first release device 1311 and the other end of the second release device 1312 respectively.

[0139] Furthermore, the phase selection device quick trigger switch position is set. If the first quick trigger switch 13116, the second quick trigger switch 13117, and the third quick trigger switch 13118 are all selected to be opened, the first release device 1311 and the saturated inductor 13114 are connected in series to form a first branch, and the quick trigger switch 13112 and the inductor 13115 are connected in series to form a second branch.

[0140] Furthermore, the order in which the first fast trigger switch 13116, the second fast trigger switch 13117, and the third fast trigger switch 13118 are closed can be flexibly set according to the order in which the first release device 1311 and the second release device 1312 are put into operation, so as to control the distribution of the fault current between the first release device 1311 and the second release device 1312.

[0141] Fig.14 for Fig.13 The control method flow of the energy release device is shown in FIG. 1 , wherein the energy release device is connected in parallel at both ends of the overvoltage circuit.

[0142] In S1411, the phase selection device is controlled to quickly trigger the switch state, the first fast trigger switch 13116 is opened, the second fast trigger switch 13117 is opened, and the third fast trigger switch 13118 is opened.

[0143] In S1412, an overvoltage protection instruction is received, and the first release device is triggered to be turned on.

[0144] In S1413 , the second release device is triggered to be turned on, and the first rapid trigger switch 13116 and the second rapid trigger switch 13117 are triggered to be turned on.

[0145] In S1414, it is detected that the current of the first release device is less than a fixed value, triggering the first release device to be turned off.

[0146] In S1415, an overvoltage protection end instruction is received, and when it is detected that the current flowing through the second release device is zero, the second release device is triggered to be turned off. Then, the energy release device is set to a hot standby state.

[0147] Fig.15 A schematic diagram of an overvoltage clamping device provided in an embodiment of the present application.

[0148] The overvoltage clamping device 15000 includes the energy release device 1512 , the damping network 1511 , the high-voltage end arrester assembly 1513 , and the low-voltage end arrester assembly 1514 mentioned above.

[0149] One end of the high-voltage end arrester assembly 1513 is connected to one end of the damping network 1511 to form a high-voltage input end of the overvoltage clamping device 15000 . The high-voltage end arrester assembly 1513 includes a plurality of arresters connected in series and parallel.

[0150] One end of the low-voltage end lightning arrester assembly 1514 is connected to one end of the energy release device 1512, the other end of the damping network 1511, and the other end of the high-voltage end lightning arrester assembly 1513. The other end of the low-voltage end lightning arrester assembly 1514 is connected to the other end of the energy release device 1512 to form the low-voltage input end of the overvoltage clamping device 15000. The low-voltage end lightning arrester assembly 1514 includes multiple lightning arresters connected in series and parallel.

[0151] The damping network 1511 at least includes a damping resistor 15112 , a damping capacitor 15113 , and a voltage-equalizing resistor 15111 . The damping resistor 15112 and the damping capacitor 15113 are connected in series and then connected in parallel with the voltage-equalizing resistor 15111 .

[0152] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. An energy release device connected in parallel at both ends of an overvoltage circuit of an electric power system, the energy release device comprising a first release device, a second release device and a phase selection device, wherein: One end of the first release device is connected to one end of the second release device to form the first input end of the energy release device; one end of the phase selection device is the second input end of the energy release device, and the other two ends of the phase selection device are respectively connected to the other end of the first release device and the other end of the second release device; The phase selection device comprises: Saturated reactor; inductance; A first fast trigger switch, one end of which is connected to one end of the saturated reactor to form a first connection end of a phase selection device, and the first connection end of the phase selection device is connected to one end of the first release device; A second fast trigger switch, one end of which is connected to one end of the inductor to form a second connection end of the phase selection device, and the second connection end of the phase selection device is connected to one end of the second release device; a third fast trigger switch, one end of which is connected to the other end of the first fast trigger switch and the other end of the second fast trigger switch, and the other end of the third fast trigger switch is connected to the other end of the saturated reactor and the other end of the inductor to form a third connection end of the phase selection device; The phase selection device is used to control the current rise rate during energy release and distribute it between the two branches: The first release device includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs, and the second release device includes at least one level of fast trigger switch component branch, and is controlled to be opened subsequently; the phase selection device is used to trigger and open the first release device and then trigger and open the second release device when receiving an overvoltage protection instruction; and the phase selection device is used to detect that the current flowing through the first release device and the second release device is zero when receiving an overvoltage protection end instruction, and trigger the shutdown of the second release device; or The second release device includes at least one power semiconductor silicon stack component branch, and is controlled to be triggered and opened first after an overvoltage fault occurs. The first release device includes at least one level of fast trigger switch component branch, and is controlled to be opened subsequently; the phase selection device, when receiving an overvoltage protection instruction, is used to trigger the opening of the second release device, and then trigger the opening of the first release device; and the phase selection device, when receiving an overvoltage protection end instruction, is used to detect that the current flowing through the first release device and the second release device is zero, and trigger the shutdown of the first release device.

2. The energy release device according to claim 1, wherein: When at least two of the power semiconductor silicon stack component branches are connected in parallel, each of the power semiconductor silicon stack component branches is connected in series with an inductor.

3. The energy release device according to claim 1, wherein: When at least two of the fast trigger switch components are connected in parallel, each of the fast trigger switch components is connected in series with an inductor.

4. The energy release device according to claim 1, wherein: The power semiconductor silicon stack component branch includes: at least one power semiconductor single stage.

5. The energy release device according to claim 4, wherein: The single-stage power semiconductor includes a thyristor, a trigger unit, a damping circuit and a voltage-equalizing resistor connected in parallel. The damping circuit includes a damping resistor and a damping capacitor connected in series. One end where the damping resistor and the damping capacitor are connected is also connected to the trigger unit.

6. The energy release device according to claim 4, wherein: The single-stage power semiconductor includes a commutation thyristor, an integrated gate trigger unit, a damping circuit and a voltage-equalizing resistor connected in parallel. The damping circuit includes a damping resistor and a damping capacitor connected in series. One end where the damping resistor and the damping capacitor are connected is also connected to the integrated gate trigger unit.

7. The energy release device according to claim 4, wherein: The single-stage power semiconductor includes a first thyristor, a first trigger unit, a damping circuit, a voltage-equalizing resistor, a second thyristor, and a second trigger unit connected in parallel. The first trigger unit controls the triggering of the first thyristor, and the second trigger unit controls the triggering of the second thyristor. The first trigger unit is connected to the second trigger unit, the anode of the first thyristor is connected to the cathode of the second thyristor, and the cathode of the first thyristor is connected to the anode of the second thyristor. The damping circuit includes a damping resistor and a damping capacitor connected in series.

8. The energy release device according to claim 4, wherein: The single-stage power semiconductor includes a first commutation thyristor, a first integrated gate trigger unit, a damping circuit, a voltage equalizing resistor, a second commutation thyristor and a second integrated gate trigger unit connected in parallel, the first integrated gate trigger unit controls the triggering of the first commutation thyristor, the second integrated gate trigger unit controls the triggering of the second commutation thyristor, the anode of the first commutation thyristor is connected to the cathode of the second commutation thyristor, the first integrated gate trigger unit is connected to the second integrated gate trigger unit, the cathode of the first commutation thyristor is connected to the anode of the second commutation thyristor, and the damping circuit includes a damping resistor and a damping capacitor connected in series.

9. The energy release device according to claim 1, wherein: The fast trigger switch component branch includes: at least one level of fast trigger switch.

10. A method for controlling an energy release device according to any one of claims 1 to 9, comprising: Control the phase selection device to quickly trigger the first fast trigger switch, the second fast trigger switch, and the third fast trigger switch of the phase selection device to open; receiving an overvoltage protection instruction and triggering the opening of the first release device; triggering and opening the second release device; When receiving an overvoltage protection end instruction and detecting that the current flowing through the first release device and the second release device is zero, the second release device is triggered to be turned off.

11. The control method according to claim 10, wherein: After the triggering and opening of the second release device, the method further comprises: The first fast trigger switch and the second fast trigger switch are triggered to turn on.

12. A method for controlling an energy release device according to any one of claims 1 to 9, comprising: Control the phase selection device to quickly trigger the first fast trigger switch, the second fast trigger switch, and the third fast trigger switch of the phase selection device to open; receiving an overvoltage protection instruction and triggering the opening of the first release device; Triggering and opening the second release device, and triggering and opening the first fast trigger switch and the second fast trigger switch; Detecting that the current of the first release device is less than a fixed value, triggering the first release device to be turned off; When receiving an overvoltage protection end instruction and detecting that the current flowing through the second release device is zero, the second release device is triggered to be turned off.

13. An overvoltage clamping device, comprising: An energy release device as claimed in any one of claims 1 to 9; A damping network, comprising at least a damping resistor, a damping capacitor, and a voltage-equalizing resistor, wherein the damping resistor is connected in series with the damping capacitor and then connected in parallel with the voltage-equalizing resistor; A high-voltage end arrester assembly, one end of which is connected to one end of the damping network to form a high-voltage input end of the overvoltage clamping device, and the high-voltage end arrester assembly includes a plurality of arresters connected in series and parallel; A low-voltage end lightning arrester assembly, one end of the low-voltage end lightning arrester assembly is connected to one end of the energy release device, the other end of the damping network, and the other end of the high-voltage end lightning arrester assembly, and the other end of the low-voltage end lightning arrester assembly is connected to the other end of the energy release device to form the low-voltage input end of the overvoltage clamping device, and the low-voltage end lightning arrester assembly includes a plurality of lightning arresters connected in series and parallel.

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