CN110971133A

CN110971133A - Reliable bypass device and converter valve power module device with same

Info

Publication number: CN110971133A
Application number: CN201911183992.5A
Authority: CN
Inventors: 蔺广科; 盛俊毅; 靳广超; 谢文杰; 林卫星
Original assignee: Tbea Xi'an Flexible Power T&d Co ltd; TBEA Xinjiang Sunoasis Co Ltd
Current assignee: Tbea Xi'an Flexible Power T&d Co ltd; TBEA Xinjiang Sunoasis Co Ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2020-04-07

Abstract

The invention discloses a reliable bypass device and a converter valve power module device with the reliable bypass device, which can be widely applied to a flexible direct-current transmission converter valve system. The overvoltage bypass device is small in size, adopts water-cooling heat dissipation for heat dissipation, effectively limits damage to the inside of the power module in the moment of overvoltage breakdown, and is high in reliability. This excessive pressure bypass device adopts the crimping formula design, and through reasonable device overall arrangement, excessive pressure thyristor and current-limiting resistance inductance adopt unilateral water-cooling heat dissipation, when limiting the module impact destruction in the twinkling of an eye that the excessive pressure punctures, consider the long-term operation reliability of excessive pressure bypass device. The flexible direct current system has the advantages of simple structure, convenient implementation and high reliability, and can avoid the problem of shutdown of the whole system caused by single module failure in the running process of the flexible direct current system, thereby ensuring the reliable running of the flexible direct current system and avoiding huge economic loss caused by the shutdown of the system.

Description

Reliable bypass device and converter valve power module device with same

Technical Field

The invention belongs to the technical field of flexible direct current power transmission, and particularly relates to a reliable bypass device and a converter valve power module device with the reliable bypass device.

Background

Due to the controllability, flexibility and stability of the flexible direct current transmission, the flexible direct current transmission has wide prospects in distributed power generation, isolated islands and urban expansion power supply, is a development direction of long-distance and large-capacity direct current transmission in the future, and development of high-reliability converter valve equipment is the most core technology.

The high-voltage flexible direct current converter valve is used for converting alternating current voltage into direct current voltage or reversely converting the direct current voltage into the alternating current voltage. The high-voltage converter valve contains a large number of power electronic periods, such as thyristors, IGBTs, IEGTs, etc.

When an abnormality such as a sub-module fault is detected in a system including a sub-module combination, a high-speed short-circuit bypass switch of a high-voltage direct-current power transmission system acts to short-circuit the sub-module and prevent the influence of the fault from spreading to other adjacent sub-modules; when the power module has a common fault working condition, the power module is cut off from a bridge arm of the converter valve through the action of the bypass switch. When the following three situations occur:

1. when the power module has a general fault, a bypass command is sent out, but the bypass switch refuses to operate;

2. when a module control board of the power module is damaged, a bypass command cannot be sent;

3. and the power module is damaged by the energy-taking power supply and cannot send a bypass command.

The bypass switch cannot complete the bypass function, the voltage of a capacitor of the power module is increased, the power device is subjected to overvoltage breakdown, and the power device cannot ensure long-term through current after breakdown, so that the system can be stopped emergently.

The flexible direct converter valve plays a role in transmitting main electric energy, and economic loss and negative influence are caused to a certain extent after the converter is stopped, so measures need to be taken to ensure that the normal operation of the system is still not influenced after the power module breaks down.

Disclosure of Invention

The invention provides a reliable bypass device and a converter valve power module device with the reliable bypass device, wherein the bypass device can still form a reliable bypass under the condition that a bypass switch of a flexible direct converter valve fails, a fault power module is cut off, the flexible direct converter valve is prevented from being stopped because of the fault of a single power module, and the flexible direct converter valve system is ensured to run reliably.

In order to achieve the above object, the reliable bypass device of the present invention comprises a first side plate, a second side plate, an overvoltage thyristor, an integrated resistor, an inductor and a heat sink; the overvoltage thyristor and the integrated resistor and inductor are arranged on two sides of the radiator, the first side plate is fixedly connected with one end of the first compression-joint disc spring, and the other end of the first compression-joint disc spring is connected with the overvoltage thyristor and generates pressure on the overvoltage thyristor, so that the overvoltage thyristor is in close contact with one side wall of the radiator; the second side plate is fixedly connected with one end of the second compression joint disc spring, and the other end of the second compression joint disc spring is connected with the integrated resistor and the inductor and generates pressure on the integrated resistor and the inductor, so that the integrated resistor and the inductor are in close contact with the other side wall of the radiator.

Furthermore, the integrated resistor and current-limiting inductor comprises a shell, a first electrode, a resistor, a filler and a second electrode, wherein the first electrode and the second electrode are respectively installed at two ends of the shell to form a cavity, the resistor is arranged in the cavity, one end of the resistor is in contact with the first electrode, the other end of the resistor is in contact with the second electrode, and the filler is filled in the cavity.

Further, the resistor body has a spiral structure.

Furthermore, the first electrode and the second electrode are two resistance pressure welding electrode surfaces, and resistance inductance is formed between the two electrodes.

Furthermore, the resistor body is made of a nickel-chromium alloy material.

Furthermore, the filler is made of quartz sand.

Further, the radiator is a water-cooled radiator.

The converter valve power module device with the reliable bypass device comprises a power module, a bypass switch K1 and the reliable bypass device, wherein the power module comprises a fully-controlled device T1, a fully-controlled device T2, a resistor R1 and a capacitor C1, the resistor R1 is connected in parallel at two ends of a bridge arm formed by the fully-controlled device T1 and the fully-controlled device T2, and the capacitor C1 is connected in parallel at two ends of a resistor R1; the bypass switch K1 is connected with the full-control device T2 in parallel, and the reliable bypass device is connected with the bypass switch K1 in parallel; the reliable bypass device is formed by connecting an overvoltage thyristor SCR, a resistor R0 and an inductor L0 in series.

Furthermore, the breakdown voltage of the overvoltage thyristor SCR ranges from 4300V to 4500V.

Further, the full-control device is an IGBT.

Compared with the prior art, the invention has at least the following beneficial technical effects:

the reliable bypass device provided by the invention has the advantages that the compression joint type resistor and the current-limiting inductor are integrally designed, the resistance value of the m omega level can be reached through the structural design of the compression joint type resistor, and the inductor of the hundreds of nH level can be reached through the spiral rising mode; through the integrated resistance inductor, the capacitance can effectively absorb the huge energy generated by the discharge of the capacitance when discharging, and other accidents such as water leakage and the like caused by the damage of devices such as a water cooling plate, a laminated busbar and the like in the power module due to the huge energy released by the capacitance can be avoided.

Furthermore, based on the power electronic device thyristor and the compression joint type resistance inductor, the compression joint type process is adopted, the structure is compact, meanwhile, the compression joint structure design ensures that the device can effectively guarantee the through-flow heat dissipation while normally working, and therefore the reliability of the overvoltage device can be effectively guaranteed.

Furthermore, the reliable bypass device comprises a first side plate, a second side plate, an overvoltage thyristor, an integrated resistor, an inductor and a radiator; the overvoltage thyristor and the integrated resistor and inductor are arranged on two sides of the radiator, the first side plate is fixedly connected with one end of the first compression-joint disc spring, and the other end of the first compression-joint disc spring is connected with the overvoltage thyristor and generates pressure on the overvoltage thyristor, so that the overvoltage thyristor is in close contact with one side wall of the radiator; the second side plate is fixedly connected with one end of the second compression joint disc spring, and the other end of the second compression joint disc spring is connected with the integrated resistor and the inductor and generates pressure on the integrated resistor and the inductor, so that the integrated resistor and the inductor are in close contact with the other side wall of the radiator. By adopting the structure, the overvoltage thyristor, the integrated resistor, the inductor and the radiator are fixed together, so that mechanical damage to the overvoltage thyristor possibly caused by other connection modes is avoided.

Furthermore, the resistor body is of a spiral structure, the target resistance inductance parameter design can be obtained through winding, and meanwhile, the resistor body is filled with quartz sand, so that the resistor body has the advantages of high temperature resistance, small thermal expansion coefficient, high insulation and corrosion resistance, and can ensure that the resistor body has very strong energy absorption capacity.

Furthermore, a water-cooling radiator is adopted for heat dissipation, so that the overhigh temperature in the operation process is avoided.

The converter valve power module device with the reliable bypass device forms a reliable through-flow branch after the overvoltage thyristor is broken down, and effectively solves the problem of system shutdown after the bypass is refused to operate; meanwhile, the problems that the inside of the power module is damaged due to huge discharge energy of the capacitor, water leakage occurs or huge electromotive force destroys a power connection loop can be solved.

Drawings

FIG. 1 is an electrical schematic diagram of a current half-bridge power module of a flexible direct current converter valve;

FIG. 2 is an electrical schematic of the present invention;

FIG. 3a is a first schematic diagram illustrating the design of the reliable bypass device of the present invention;

FIG. 3b is a schematic illustration of the reliable bypass device design of the present invention;

FIG. 4 is a schematic diagram of a converter valve bridge arm formed by the power module of the present invention;

FIG. 5 is a mechanical schematic of a single power module;

FIG. 6a is a schematic view of an overpressure bypass apparatus;

FIG. 6b is a schematic diagram of an integrated crimp resistor inductor;

fig. 7 is a schematic diagram of a full-bridge embodiment.

In the drawings: 1. the device comprises a bypass switch, 2, an overvoltage bypass device, 3, an IGBT compression joint component, 4, a capacitor, 5, a discharge resistor, 21, an overvoltage thyristor, 22, an integrated resistor and inductor, 23, a radiator, 25 and a compression joint disc spring; 221. a first electrode; 222. a resistor body; 223. a filler; 224. a second electrode.

Detailed Description

In order to make the objects and technical solutions of the present invention clearer and easier to understand. The present invention will be described in further detail with reference to the following drawings and examples, wherein the specific examples are provided for illustrative purposes only and are not intended to limit the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 2, a converter valve power module device with a reliable bypass device comprises an overvoltage thyristor 21, an integrated resistor and inductor 22 and a current-limiting inductor 23. The reliable bypass device, the bypass switch 1, the capacitor 4, the discharge resistor 5, the power device IGBT 3 and the like form a complete power module unit.

When the bypass switch 1 refuses to operate after the power unit fails, the current of the bridge arm continues to supply to the capacitor C₁Charging when the capacitor C is charged₁When the voltage is larger than 4500V, the power device T1 breaks down, when T1 breaks down, the capacitor voltage is directly applied to two ends of the overvoltage thyristor 21, when the capacitor voltage is larger than 4300V, the overvoltage thyristor breaks down, the current flows through the integrated resistor and inductor 22, and the capacitor energy is released, as shown in fig. 3 a.

When the thyristor is broken down in overvoltage, bridge arm current flows through the thyristor SCR, the resistor R0 and the current-limiting inductor L0, and the power module is reliably bypassed; the crimping resistor R0 is used for absorbing energy released by the partial capacitor C1, a current peak value appears in a circuit, and the current limiting inductor L0 can be used for current limiting, so that the current is prevented from being changed too much, normal operation of a system can be ensured, and the current flows to the current direction as shown in figure 3 b.

The specific principle is shown in fig. 4, the bridge arm current flows from a to b, the bridge arm of the converter valve consists of n half-bridge power modules, when the bypass fails after the power module SM2 fails, overvoltage breakdown occurs in an overvoltage bypass device in the SM2, and the current flows to the state shown in fig. 4 after the overvoltage breakdown, so that the system shutdown caused by single-module failure can be avoided.

Example 1

A converter valve half-bridge power module device with a reliable bypass device comprises a half-bridge power module, a bypass switch K1 and the reliable bypass device, wherein the half-bridge power module comprises an IGBT T1, an IGBT T2, a resistor R1 and a capacitor C1, the resistor R1 is connected in parallel at two ends of a bridge arm formed by the IGBT T1 and the IGBT T2, and the capacitor C1 is connected in parallel at two ends of a resistor R1. The bypass switch K1 is connected in parallel with the IGBT T2, and the reliable bypass device is connected in parallel with the bypass switch K1. The reliable bypass device is formed by connecting an overvoltage thyristor SCR, a resistor R0 and an inductor L0 in series.

Referring to fig. 2 to fig. 6a and fig. 6b, the invention is described in combination with an overvoltage device adopted in the case of bypass failure after a power module of the ± 800kV flexible dc converter valve fails to avoid system shutdown caused by a single module failure, but the invention is not limited to the ± 800kV flexible dc converter valve product, and is also applicable to the protection concept of key devices in flexible dc products of other voltage classes, static synchronous compensators (STATCOM) or static var compensators (SVG).

Fig. 1 is an electrical component of a conventional power module, and when a bypass fails, a power device is damaged due to a rise in voltage of the power module, and a system is stopped due to the fact that a long-term current cannot flow after the power device is damaged. Fig. 2 is a scheme for solving the system shutdown caused by bypass operation failure after the power module fails, and an overvoltage device unit is formed by adopting an overvoltage thyristor and a resistance inductor.

Fig. 3a and 3b are technical details of specific implementations: in fig. 3a, when the power module fails and the bypass fails, the voltage of the capacitor of the power module continuously increases, and the overvoltage thyristor breaks down after the voltage of the power module increases, so that the capacitor releases huge energy and current flows as shown by an arrow in fig. 3 a; when the power overvoltage device breaks down, the system current continues to transmit electric energy through the overvoltage bypass device, and the current flows to the state shown in fig. 3 b; the slave system schematic is shown in fig. 4.

Detailed power unit as shown in fig. 5, a single power module includes a bypass switch 1, an overvoltage device 2, an IGBT crimping component 3, a capacitor 4 and a discharging resistor 5, and the corresponding electrical power module schematic diagram is shown in fig. 2.

Referring to fig. 6a, the reliable bypass device mainly includes a first side plate 241, a second side plate 242, an overvoltage thyristor 21, an integrated resistor and inductor 22, and a heat sink 23. The overvoltage thyristor 21 and the integrated resistor and inductor 22 are arranged on two sides of the radiator 23, and the overvoltage thyristor 21 and the integrated resistor and inductor 22 are integrally connected in a compression joint mode to form a bypass overvoltage device for water-cooling heat dissipation of the single side of the overvoltage thyristor 21 and the integrated resistor and inductor 22. When the power module fault bypass switch K1 refuses to operate, the bypass overvoltage device 2 is subjected to overvoltage breakdown to form a reliable passage, and system outage caused by single module fault of the flexible direct current converter valve is avoided.

The first side plate 241 and the second side plate 242 are fixed by a connecting rod, the first side plate 241 is fixedly connected with one end of a first compression disc spring, and the other end of the first compression disc spring is connected with the overvoltage thyristor 21 and generates pressure on the overvoltage thyristor 21, so that the overvoltage thyristor 21 is in close contact with one side wall of the radiator 23; the second side plate 242 is fixedly connected to one end of the second compression-connection disc spring, and the other end of the second compression-connection disc spring is connected to the integrated resistor and inductor 22, and generates pressure on the integrated resistor and inductor 22, so that the integrated resistor and inductor 22 is in close contact with the other side wall of the heat sink 23, thereby forming a compression-connection structure. By adopting the structure, the overvoltage thyristor 21, the integrated resistor and inductor 22 and the radiator 23 are fixed together, so that mechanical damage to the overvoltage thyristor 21 caused by other connection modes is avoided.

The integrated resistor and current-limiting inductor 22 is of a press-fit type, as shown in fig. 6b, and comprises a housing 225, a first electrode 221, a resistor 222, a filler 223, and a second electrode 224, wherein the first electrode 221 and the second electrode 224 are respectively mounted at two ends of the housing 225 to form a cavity, the resistor 222 is disposed in the cavity, one end of the resistor 222 is in contact with the first electrode 221, the other end of the resistor is in contact with the second electrode, and the filler 223 is filled in the cavity. The resistor 222 is an inductor of several hundred nH level by spiral rising; through the integrated resistance inductor, the huge energy generated when the capacitor discharges is effectively absorbed when the capacitor discharges, and other accidents such as water leakage and the like caused by damage of devices such as a water cooling plate and a laminated busbar in a power module due to the huge energy released by the capacitor are avoided.

The resistor (222) is made of nichrome, and may be made of a similar alloy material.

The filler (223) is quartz sand material, and can also be selected from high temperature resistant, small thermal expansion coefficient, high insulation and corrosion resistant material.

The breakdown voltage of the overvoltage thyristor 21 is 4300V-4500V, the lower limit of the voltage value is a certain margin left on the basis of the system overvoltage protection value in actual work, the upper limit is lower than 4500V to protect the IGBT device, the voltage of the IGBT device is 4500V, and the IGBT device does not have a gate trigger function. The resistance value of the overvoltage thyristor after breakdown is required to be less than 2m omega.

The crimping resistor and the current-limiting inductor 22 are of an integrated crimping structure, and are connected with the overvoltage thyristor 21 in series and then connected with the capacitor C in a crimping mode₁Forming a loop; the resistance value is 3.5m omega, the nickel-chromium alloy is processed, the positive selection half-wave current with the peak current of 700kA and the period of 200uS is endured, and the inductance is 250 nH. The crimping resistor and the current-limiting inductor can bear 1500A current for a long time, and the temperature rise is less than 75K.

Example 2

Referring to fig. 7, the converter valve full-bridge power module device with the reliable bypass device comprises a full-bridge power module, a bypass switch K1 and the reliable bypass device, wherein the full-bridge power module comprises an IGBT T1, an IGBT T2, an IGBT T3, an IGBT T4, a resistor R1 and a capacitor C1, the IGBT T1 and the IGBT T2 are on the same bridge arm, and the IGBT T3 and the IGBT T4 are on the same bridge arm; the resistor R1 is connected in parallel at two ends of a bridge arm formed by the IGBT T1 and the IGBT T2, and the capacitor C1 is connected in parallel at two ends of the resistor R1. The bypass switch K1 is connected in parallel with the IGBTT2 and the reliable bypass device is connected in parallel with the bypass switch K1. The reliable bypass device is formed by connecting an overvoltage thyristor SCR, a resistor R0 and an inductor L0 in series.

The overvoltage device based on the overvoltage thyristor can be widely used in a flexible direct-current transmission converter valve system, has a simple structure, adopts a compression joint type structure, and has good electrical connection stability; the heat dissipation adopts water cooling heat dissipation, so that the overhigh temperature in the operation process is avoided; in addition, through the effect of crimping formula resistance and inductance, reduce the moment energy value that the electric capacity released after the overvoltage breakdown, can effectively restrict the damage to power module inside in the twinkling of an eye in the overvoltage breakdown. Therefore, the flexible direct current transmission system has high overall reliability and can be used in a flexible direct current transmission system with high reliability requirement.

The overvoltage bypass device is reasonably arranged, the overvoltage thyristor and the current-limiting resistance inductor adopt unilateral water-cooling heat dissipation, and the long-term operation reliability of the overvoltage bypass device is considered while the module is prevented from being damaged by impact in the moment of overvoltage breakdown. The invention can avoid the problem of shutdown of the whole system caused by single module failure in the running process of the flexible direct current converter valve system, thereby ensuring the reliable running of the flexible direct current system and avoiding huge economic loss caused by the shutdown of the system.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A reliable bypass device is characterized by comprising a first side plate (241), a second side plate (242), an overvoltage thyristor (21), an integrated resistor and inductor (22) and a radiator (23); the overvoltage thyristor (21) and the integrated resistor and inductor (22) are arranged on two sides of the radiator (23), the first side plate (241) is fixedly connected with one end of the first compression-connection disc spring, the other end of the first compression-connection disc spring is connected with the overvoltage thyristor (21) and generates pressure on the overvoltage thyristor (21), and the overvoltage thyristor (21) is in close contact with one side wall of the radiator (23); the second side plate (242) is fixedly connected with one end of the second compression-connection disc spring, the other end of the second compression-connection disc spring is connected with the integrated resistor and inductor (22), pressure is generated on the integrated resistor and inductor (22), and the integrated resistor and inductor (22) is in close contact with the other side wall of the radiator (23).

2. The device of claim 1, wherein the integrated resistor and current-limiting inductor (22) comprises a housing (225), a first electrode (221), a resistor (222), a filler (223), and a second electrode (224), wherein the first electrode (221) and the second electrode (224) are respectively mounted at two ends of the housing (225) to form a cavity, the resistor (222) is disposed in the cavity, one end of the resistor (222) is in contact with the first electrode (221), the other end of the resistor is in contact with the second electrode, and the filler (223) is filled in the cavity.

3. A positive bypass device according to claim 2, characterized in that the resistive body (222) is a spiral structure.

4. A positive bypass device according to claim 2, characterized in that the first (221) and second electrodes are resistive and pressure-bonded electrode surfaces, and resistive inductance is formed between the two electrodes.

5. A positive bypass device according to claim 2, characterized in that the resistive element (222) is made of nichrome material.

6. A positive bypass device according to claim 2, characterized in that said filler (223) is selected from a quartz sand material.

7. A positive bypass device according to claim 1, characterized in that the radiator (23) is a water-cooled radiator.

8. The converter valve power module device with the reliable bypass device of claim 1, characterized by comprising a power module, a bypass switch K1 and the reliable bypass device, wherein the power module comprises a fully-controlled device T1, a fully-controlled device T2, a resistor R1 and a capacitor C1, the resistor R1 is connected in parallel at two ends of a bridge arm formed by the fully-controlled device T1 and the fully-controlled device T2, and the capacitor C1 is connected in parallel at two ends of a resistor R1; the bypass switch K1 is connected with the full-control device T2 in parallel, and the reliable bypass device is connected with the bypass switch K1 in parallel; the reliable bypass device is formed by connecting an overvoltage thyristor SCR, a resistor R0 and an inductor L0 in series.

9. The converter valve power module device with a reliable bypass device according to claim 8, wherein the breakdown voltage of the overvoltage thyristor SCR is 4300V to 4500V.

10. The converter valve power module arrangement with reliable bypass arrangement according to claim 8, characterized in that said fully controlled device is an IGBT.