CN216356463U - Valve unit with fault protection function and converter valve system - Google Patents

Abstract

The utility model discloses a valve unit and converter valve unit with fault protection function, the valve unit that wherein has fault protection function includes: a bridge circuit comprising at least two power components; the driving control module is connected with the control end of the power component; the clamping unit is connected between the power component and the drive control module; and the adjusting unit is connected with the clamping unit and can adjust the threshold value of the clamping unit. When a fault occurs, the threshold value of the clamping unit is reduced by the adjusting unit, the power component connected with the clamping unit is damaged and broken to be in a short-circuit state, the valve unit is in the short-circuit state through the sacrificial damaged power component, and the fault influence is avoided from further expansion. Under the normal operating condition, the threshold value of the clamping unit can be improved by the adjusting unit, so that the heat productivity of the clamping unit is reduced, the practical service life and the reliability are prolonged, and meanwhile, the direct-current voltage utilization rate of the valve unit is improved.

Description

Valve unit with fault protection function and converter valve system

Technical Field

The utility model relates to a flexible direct current transmission field, in particular to valve unit and change of current valve system with fault protection function.

Background

In the field of flexible direct current transmission, a converter valve is formed by cascading a plurality of valve units, and when a valve unit fails, the failed valve unit is required to be in a short-circuit state so as to prevent dangers caused by overhigh capacitor voltage or short-circuit discharge of capacitors in the failed valve unit and enable the rest of the valve units to work normally.

When the converter valve is started for the first time, if the valve unit cannot work due to the energy-taking power supply, the valve unit is a black module for an upper-level valve control system, and the valve unit cannot trigger the bypass to be in a short-circuit state, so that larger faults are caused. Or, when the valve unit is in failure, the bypass switch may not be operated due to a mechanical failure or a failure of the driving module, so that the valve unit may be in a short-circuit state.

In the prior art, a clamping circuit is arranged in a valve unit of a part of converter valves and is connected with a power device in the valve unit, and when a fault occurs, the clamping circuit is broken down, so that the power device is conducted, and further, the power device is damaged and broken down due to overlarge current, so that the valve unit is in a short-circuit state. However, the protection threshold of the clamp circuit is low, which causes the efficiency of the transient voltage suppression diode in the clamp circuit to be low under high voltage, and further the transient voltage suppression diode generates heat to seriously affect the service life and reliability, and meanwhile, the protection threshold of the clamp circuit is low, which causes that the highest direct current voltage cannot be too high when the valve unit normally works, and affects the voltage utilization rate of the whole valve unit.

Practical contents

The utility model aims at solving at least one of the technical problems existing in the prior art. To this end, the present application proposes a valve unit with a failsafe function, which is capable of adjusting the threshold value of the clamping unit.

The utility model also provides a change of current valve system, it can be under the trouble condition, adjusts clamping unit's threshold value, makes the power component damage breakdown that corresponds present the short circuit state.

According to the utility model discloses valve unit with fail safe function of first aspect embodiment includes: a bridge circuit comprising at least two power components; the driving control module is connected with the control end of the power component; at least one clamping unit connected between the power component and the drive control module; and the adjusting unit is connected with the clamping unit and can adjust the threshold value of the clamping unit.

According to this practical embodiment's valve unit with fault protection function has following beneficial effect at least: when a fault occurs, the threshold value of the clamping unit is reduced by the adjusting unit, so that the clamping unit is easier to break down, the power component connected with the clamping unit is damaged and broken down to be in a short-circuit state, the valve unit can be in the short-circuit state through sacrificing the power component under the fault condition, the fault influence is avoided, further expansion is avoided, and the reliability is improved. Under the normal operating condition, the threshold value that the regulating unit can improve the clamping unit is favorable to improving the efficiency of clamping unit, reduces clamping unit's calorific capacity, extension practical life and reliability, simultaneously, improves clamping unit's threshold value, also is favorable to improving valve unit's direct current voltage utilization ratio. Therefore, by adjusting the threshold value of the clamping unit, the use requirement can be met under the conditions of failure and normal operation.

According to some embodiments of the present disclosure, the clamping unit includes a switch Q1 and a plurality of tvs connected in series to form a series link, a cathode of the series link is connected to the power module, an anode of the series link is connected to the drive control module and/or a control terminal of the power module, the adjusting unit is connected to a control terminal of the switch Q1, the switch Q1 is connected to the series link, and the switch Q1 is turned on to short-circuit at least one of the tvs.

According to some embodiments of the present disclosure, the clamping unit further comprises a diode D13, an anode of the diode D13 is connected with the power component, and a cathode of the diode D13 is connected with a cathode of the series link.

According to some embodiments of the present disclosure, the adjusting unit includes a switch Q2 and a resistor R1, one end of the resistor R1 is connected to the power module, the other end of the resistor R1 is connected to the control end of the switch Q1 and the one end of the switch Q2, and the other end of the switch Q2 and the control end of the switch Q2 are connected to the driving control module.

According to some embodiments of the present disclosure, the clamping unit further includes a resistor R11, a capacitor C11, and a resistor R13, one end of the resistor R11 is connected to one end of the capacitor C11 and an anode of the series link, respectively, the other end of the resistor R11 is connected to the other end of the capacitor C11, the control end of the switch Q1, and one end of the resistor R13, and the other end of the resistor R13 is connected to the control end of the power module.

According to some embodiments of the present disclosure, the clamping unit further includes a trigger circuit, and the control terminal of the switching tube Q1 is connected to the control terminal of the power component and the driving control module through the trigger circuit respectively.

According to some embodiments of the present invention, the trigger circuit includes a resistor R12, a voltage regulator ZD11 and a diode D12, one end of the resistor R13 is connected to the control terminal of the driving control module and the power module, the other end of the resistor R13 is connected to one end of the resistor R12 and the cathode of the voltage regulator ZD11, the anode of the voltage regulator ZD11 is connected to the anode of the diode D12, and the other end of the resistor R12 is connected to the cathode of the diode D12 and the control terminal of the switch Q1.

According to some embodiments of the present disclosure, the number of the power components is two, two of the power components are connected to form a half-bridge circuit, the number of the clamping units is two, the clamping units are connected to the power components in a one-to-one correspondence, the number of the adjusting units is one, and the clamping units connected to the middle and lower tubes of the half-bridge circuit are connected to the adjusting units.

According to some embodiments of the present disclosure, the number of the power components is four, four power components are connected to form a full bridge circuit, four clamping units are connected to the power components in a one-to-one correspondence, and two adjusting units are connected;

the two clamping units correspondingly connected with the two lower tubes in the full-bridge circuit are respectively connected with the adjusting units in a one-to-one correspondence manner;

or the two clamping units correspondingly connected with the two upper tubes in the full-bridge circuit are respectively connected with the adjusting units in a one-to-one correspondence mode.

According to the second aspect of the present invention, a converter valve system comprises: the at least two valve units with the fault protection function are cascaded between the bridge circuits, and further comprise a valve control module and a main control module which is connected with the drive control module in a one-to-one correspondence mode, wherein the valve control module is in communication connection with the main control module.

According to the converter valve system of the embodiment of the utility model, at least the following beneficial effects are achieved: when a certain valve unit has a black fault, the threshold value of the clamping unit is reduced by the adjusting unit in the faulted valve unit, so that the clamping unit is easier to break down, the power component connected with the clamping unit is damaged and broken down to be in a short-circuit state, the faulted valve unit is in the short-circuit state by sacrificing the power component, other normally working valve units are not influenced, the fault is prevented from further expanding, and the reliability is improved. Under the normal operating condition, the threshold value that the regulating unit can improve the clamping unit is favorable to improving the efficiency of clamping unit, reduces clamping unit's calorific capacity, extension practical life and reliability, simultaneously, improves clamping unit's threshold value, also is favorable to improving valve unit's direct current voltage utilization ratio. Therefore, by adjusting the threshold value of the clamping unit, the use requirement can be met under the conditions of failure and normal operation.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a circuit diagram of one embodiment of a valve unit with fault protection of the present invention;

FIG. 2 is a circuit diagram of one embodiment of a half-bridge circuit of the present invention;

FIG. 3 is a circuit diagram of one embodiment of a full bridge circuit of the present invention;

FIG. 4 is a circuit diagram of another embodiment of a full bridge circuit of the present invention;

FIG. 5 is a schematic diagram illustrating the forward current flow of the circuit diagram of FIG. 3;

FIG. 6 is a schematic diagram illustrating the reverse current flow of the circuit diagram of FIG. 3;

fig. 7 is a block diagram of a converter valve system according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary only for the purpose of explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present application, it is to be understood that the positional descriptions, such as the directions of up, down, front, rear, left, right, etc., referred to are based on the directions or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the present application.

In the description of the present application, if there are first and second described only for the purpose of distinguishing technical features, it is not understood that relative importance is indicated or implied or that the number of indicated technical features or the precedence of the indicated technical features is implicitly indicated or implied.

In the description of the present application, unless explicitly defined otherwise, terms such as setting, installing, connecting and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present application by combining the specific contents of the technical solutions.

As shown in fig. 1 to 4, a valve unit with a fail-safe function according to an embodiment of the present invention includes: a bridge circuit comprising at least two power components 100; a driving control module 200 connected to a control terminal of the power module 100; at least one clamping unit 300, the clamping unit 300 being connected between the power component 100 and the driving control module 200; and at least one adjusting unit 400 connected to the clamping unit 300, wherein the adjusting unit 400 can adjust the threshold of the clamping unit 300.

When a fault occurs, the adjusting unit 400 reduces the threshold of the clamping unit 300, so that the clamping unit 300 is more easily broken down, and further the power component 100 connected with the clamping unit 300 is damaged and broken down to be in a short-circuit state, and the valve unit can be in the short-circuit state by sacrificing the power component 100 under the fault conditions that the black module or the bypass switch 600 cannot act and the like, thereby avoiding further expansion of fault influence and improving reliability. Under the normal working condition, the adjusting unit 400 can improve the threshold value of the clamping unit 300, thereby being beneficial to improving the efficiency of the clamping unit 300, reducing the heat productivity of the clamping unit 300, prolonging the practical life and reliability, and simultaneously improving the threshold value of the clamping unit 300 and being beneficial to improving the direct-current voltage utilization rate of the valve unit. Therefore, by adjusting the threshold value of the clamping unit 300, the use requirement can be met under the conditions of failure and normal operation.

The power module 100 includes a power transistor and a diode connected in anti-parallel with the power transistor. Referring to fig. 1 to 4, in some embodiments of the present invention, the power transistor is an IGBT, a collector of the IGBT is connected to a cathode of the diode, an emitter of the IGBT is connected to an anode of the diode, and a gate of the IGBT is a control terminal.

The driving control module 200 may be implemented by a device including a single chip, an FPGA, a DSP, a CPLD, or an embedded chip.

Referring to fig. 1 to 4, in some embodiments of the present invention, the clamping unit 300 includes a switching tube Q1 and a plurality of tvs connected in series to form a series link 310, a cathode of the series link 310 is connected to the power module 100, an anode of the series link 310 is connected to the control terminal of the driving control module 200 and/or the power module 100, the adjusting unit 400 is connected to the control terminal of the switching tube Q1, the switching tube Q1 is connected to the series link 310, and the switching tube Q1 is turned on to short-circuit at least one tvs.

When the voltage at two ends of the transient voltage suppression diode (TVS) is larger than the breakdown voltage, the current flowing through the transient voltage suppression diode is increased sharply, and meanwhile, the voltage at two ends of the transient voltage suppression diode is basically stable and unchanged, so that the clamping effect is realized. The plurality of transient voltage suppression diodes are connected in series to form the series link 310, and the breakdown voltage of the series link 310 is equal to the sum of the breakdown voltages of the transient voltage suppression diodes, so that the number of the transient voltage suppression diodes can be set as required to set the breakdown voltage, and the transient voltage suppression circuit is simple in structure and convenient to implement.

Under the condition of a fault, the regulating unit 400 controls the switching tube Q1 to be conducted, so that at least one transient voltage suppression diode is short-circuited, and the breakdown voltage of the serial link 310 is reduced, so that the serial link 310 is more easily broken down, and after the serial link 310 is broken down, a large current flows to the control end of the driving control module 200 and/or the power component 100 through the serial link 310, so that the power component 100 is conducted, and the power component 100 is broken down and broken down in a large current working state to be in a short-circuit state.

Under normal operating conditions, the regulating unit 400 controls the switching tube Q1 to be cut off, so that the breakdown voltage of the serial link 310 is increased, false triggering can be prevented under normal operating conditions, the highest direct-current voltage can meet the use requirement when the valve unit normally operates, and the voltage utilization rate is favorably improved.

Referring to fig. 1, in some embodiments of the present invention, the clamping unit 300 further includes a diode D13, an anode of the diode D13 is connected with the power assembly 100, and a cathode of the diode D13 is connected with a cathode of the series link 310.

By providing the diode D13, the current can only flow to the series link 310 by utilizing the unidirectional conduction characteristic of the diode D13, which is beneficial to more stabilizing the current flow and improving the reliability.

In the serial link 310, a plurality of tvs are connected in series in the same direction, a cathode of the serial link 310 refers to one end connected to a cathode of the tvs, and an anode of the serial link 310 refers to one end connected to an anode of the tvs.

Referring to fig. 1, in some embodiments of the present invention, the adjusting unit includes a switch Q2 and a resistor R1, one end of the resistor R1 is connected to the power module 100, the other end of the resistor R1 is connected to the control end of the switch Q1 and one end of the switch Q2, and the other end of the switch Q2 and the control end of the switch Q2 are both connected to the driving control module 200.

When faults such as incapability of acting of the bypass switch 600 occur, the driving control module 200 can work normally, the driving control module 200 can control the conduction of the switching tube Q1 through the resistor R21 and the switching tube Q2, so that the breakdown voltage of the clamping unit 300 is reduced, and the power component 100, namely the power tube, is damaged and broken down to be in a short-circuit state. Therefore, under the condition of a fault of the bypass switch 600, the driving control module 200 can actively cause the power tube to be damaged and broken down according to the working state of the valve unit or the superior instruction, which is beneficial to improving the reliability.

Referring to fig. 1, in some embodiments of the present invention, the clamping unit 300 further includes a resistor R11, a capacitor C11, and a resistor R13, wherein one end of the resistor R11 is connected to one end of the capacitor C11 and the anode of the serial link 310, the other end of the resistor R11 is connected to the other end of the capacitor C11, the control end of the switch Q1, and one end of the resistor R13, and the other end of the resistor R13 is connected to the control end of the switch Q1.

Under the condition that a black module appears, namely when an energy-saving power supply in a valve unit cannot work, the driving control module 200 cannot work normally to drive the power component 100 to be conducted, at the moment, when the voltage borne by the power component 100 exceeds the breakdown voltage of the serial link 310, a large current flows to the resistor R11 and the capacitor C11 through the serial link 310 to drive the switching tube Q1 to be conducted, the current is further increased, meanwhile, the current forms the voltage for driving the power component 100, namely the power tube to be conducted through the resistor R13, the power tube is conducted for a long time under the large-current working environment, and then is damaged and broken down to be in a short-circuit state. With the structure, the power component 100 can be damaged and broken down to be in a short circuit state when the driving control module 200 cannot normally work under the condition of a black module, which is beneficial to improving the reliability.

Referring to fig. 1, in some embodiments of the present invention, the clamping unit 300 further includes a trigger circuit 320, and the control terminal of the switching tube Q1 is connected to the control terminal of the power module 100 and the driving control module 200 through the trigger circuit 320, respectively.

Other components in the circuit may be affected due to the power component 100, i.e., the power transistor, which may spike when turned off. In contrast, by providing the trigger circuit 320, the driving control module 200 controls the power component 100, that is, when the power transistor is turned on, the trigger circuit 320 turns on the switching transistor Q1, and further reduces the breakdown voltage of the clamping unit 300, when the driving control module 200 controls the power transistor to be turned off and peak fluctuation occurs, the breakdown voltage of the clamping unit 300 is still in a reduced state, and the peak fluctuation breaks through the clamping unit 300 and is absorbed by the clamping unit 300, so that the influence of the peak fluctuation on other devices is reduced, and the reliability is improved. After the power tube is turned off, the switching tube Q1 is also turned off, so that the breakdown voltage of the clamping unit 300 is increased, which is beneficial to improving the voltage utilization rate.

Referring to fig. 1, in some embodiments of the present invention, the trigger circuit 320 includes a resistor R12, a voltage regulator ZD11 and a diode D12, one end of the resistor R13 is connected to the control terminals of the driving control module 200 and the power module 100, the other end of the resistor R13 is connected to one end of the resistor R12 and the cathode of the voltage regulator ZD11, the anode of the voltage regulator ZD11 is connected to the anode of the diode D12, and the other end of the resistor R12 is connected to the cathode of the diode D12 and the control terminal of the switch Q1.

When the driving control module 200 drives the power tube to be turned on, the driving control module 200 drives the switch tube Q1 to be turned on through the resistor R13, the voltage regulator tube ZD11 and the diode D12, that is, when the power tube is turned on, the breakdown voltage of the clamping unit 300 is reduced, so that when the driving control module 200 controls the power tube to be turned off and spike fluctuation is generated, due to factors such as the capacitor C11 and the like and the model of the switch tube Q1, the turn-off time point of the switch tube Q1 is later than the turn-off time point of the power tube, so that when the spike fluctuation is generated, the breakdown voltage of the clamping unit 300 is still in a reduced state, and the spike fluctuation can break through the clamping unit 300 and be absorbed by the clamping unit 300, thereby reducing the influence of the spike fluctuation on other devices and being beneficial to improving the reliability.

Referring to fig. 1, in some embodiments of the present invention, a diode D11 and a diode D21 are further included, an anode of the diode D11 is connected to the other end of the resistor R11, the other end of the capacitor C11, the other end of the resistor R12, and a cathode of the diode D12, respectively, and a cathode of the diode D11 is connected to the control terminal of the switching tube Q1; the anode of the diode D21 is connected to the other end of the resistor R1 and one end of the switching tube Q2, and the cathode of the diode D21 is connected to the control end of the switching tube Q1.

By providing the diode D11 and the diode D21, the flowing direction of the current can be limited according to the unidirectional conduction characteristic of the diode, so that the current flowing through the resistor R1 and the current flowing through the resistor R11 or the current flowing through the resistor R13 do not interfere with each other, and the reliability is improved.

Referring to fig. 1, in some embodiments of the present invention, a voltage regulator ZD21 is further included, an anode of the voltage regulator ZD21 is connected to one end of a resistor R11, one end of a capacitor C11, and an anode of the series link 310, respectively, and a cathode of the voltage regulator ZD21 is connected to one end of a resistor R1, one end of a switch Q2, and a control end of a switch Q1, respectively.

Through being provided with the regulator tube ZD21, can prevent that the control end voltage of switch tube Q1 is too high to protection switch tube Q1 is favorable to improving the reliability.

Referring to fig. 1 and 2, in some embodiments of the present invention, the number of power modules 100 is two, two power modules 100 are connected to form a half-bridge circuit, the number of clamping units 300 is two, the clamping units 300 are connected to the power modules 100 in a one-to-one correspondence, the number of adjusting units 400 is one, and the clamping units 300 connected to the middle and lower tubes of the half-bridge circuit are connected to the adjusting units 400.

Two power components 100, two power tubes are connected in series to form a half-bridge circuit, the half-bridge circuit is connected in parallel with a dc capacitor 700, and two power tubes are connected with a clamping unit 300, and are used as power tubes of a lower tube of the half-bridge circuit, and the clamping unit 300 connected with the clamping unit is further connected with a regulating unit 400. At this time, the regulating unit 400 reduces the breakdown voltage of the clamping unit 300 corresponding to the lower tube, the breakdown voltage of the clamping unit 300 corresponding to the upper tube is greater than the breakdown voltage of the clamping unit 300 corresponding to the lower tube, so that the power tube serving as the lower tube is damaged and broken down to be in a short-circuit state, that is, a path of system current is formed, the voltage of the direct current capacitor 700 does not rise any more, the power tube serving as the upper tube is still in a normal cut-off state, the current of the direct current capacitor 700 is not released to form large current, influence is caused on other devices to expand a fault range, the failed valve unit is cut off at this time, the failed valve unit does not influence the operation of the whole system any more, and the dangerous situation of short-circuit discharge of the direct current capacitor 700 does not occur. The normal and safe operation of the system is maintained at the cost of damaging and breaking down one power tube, and the reliability is favorably improved.

Referring to fig. 1, 3 and 4, in some embodiments of the present invention, the number of the power components 100 is four, four power components 100 are connected to form a full bridge circuit, the number of the clamping units 300 is four and is connected to the power components 100 in a one-to-one correspondence, and the number of the adjusting units 400 is two;

the two clamping units 300 correspondingly connected with the two lower tubes in the full-bridge circuit are respectively and correspondingly connected with the adjusting units 400 one by one;

alternatively, the two clamping units 300 correspondingly connected to the two upper tubes in the full bridge circuit are respectively connected to the adjusting units 400 in a one-to-one correspondence.

Four power modules 100, i.e., four power tubes, are connected to form a full bridge circuit, and each power tube is connected to a clamping unit 300. Referring to fig. 3, as an embodiment, the power module 100 includes an IGBT and a diode, the IGBT2 and the IGBT4 are two lower tubes of a full bridge circuit, and the two clamping units 300 correspondingly connected thereto are also respectively connected to the adjusting units 400 in a one-to-one correspondence.

When the external input current is in the forward direction in the case of a fault and a failure of the bypass switch 600, referring to fig. 3 and 5, the current flows through the diode D1, the dc capacitor 700, and the diode D4 in sequence, and at this time, since the diode D1 and the diode D4 are turned on, the voltage across the IGBT1 and the IGBT4 approaches zero, and the voltage of the dc capacitor 700 is borne by the IGBT2 and the IGBT 3. As the dc capacitor 700 is charged to increase the voltage, when the voltage is greater than the breakdown voltage of the clamp unit 300 corresponding to the IGBT2, the IGBT2 is turned on, the adjusting unit 400 decreases the breakdown voltage of the clamp unit 300 to further increase the current flowing through the IGBT2, so that the IGBT2 is heated to be damaged and broken down, and due to the existence of the adjusting unit 400, the IGBT2 is quickly damaged and broken down, the IGBT3 is not broken down, and the IGBT1 is still in a cut-off state at this time, so that the dc capacitor 700 is not short-circuited to discharge.

When the IGBT2 is damaged and broken down and the external input current is in the reverse direction, referring to fig. 3 and 6, the current flows through the diode D3, the dc capacitor 700, and the diode D2 in sequence, and since the diode D3 and the diode D2 are turned on, the voltage of the dc capacitor 700 is received by the IGBT1 and the IGBT 4. With the voltage rise caused by the charging of the direct current capacitor 700, when the voltage is greater than the breakdown voltage of the clamp unit 300 corresponding to the IGBT4, the IGBT4 is turned on, the regulating unit 400 reduces the breakdown voltage of the clamp unit 300, so that the current flowing through the IGBT4 is further increased, the IGBT4 is further heated and damaged and broken, and due to the existence of the regulating unit 400, the IGBT4 is quickly damaged and broken, and the IGBT1 is not broken.

Through the process, the IGBT2 and the IGBT4 are damaged and broken down to form a current forward and reverse circulation channel, the failed valve unit can be in a short-circuit state, the operation of the whole system is not affected, the voltage of the direct current capacitor 700 in the failed valve unit cannot rise again, the direct current capacitor 700 cannot be in a short-circuit discharge dangerous condition, the safe operation of the system under the condition that the black module or the bypass switch 600 cannot work and the like, and the reliability is improved at the cost of sacrificing two IGBT tubes.

Referring to fig. 4, as another embodiment, the power module 100 includes IGBT transistors and diodes, the IGBT1 and the IGBT3 are two upper transistors of a full bridge circuit, and the two clamping units 300 correspondingly connected thereto are also respectively connected to the adjusting units 400 in a one-to-one correspondence. Similarly to the above-mentioned embodiment in which the clamp units 300 connected to the IGBTs 2 and 4 are also connected to the regulating unit 400, in the same way, the IGBTs 1 and 3 are damaged and broken down to form forward and reverse current channels, so that the failed valve unit is in a short-circuit state at the expense of the IGBTs 1 and 3, and the operation of the whole system is maintained.

Referring to fig. 1 and 7, a converter valve system according to a second aspect of the present invention includes: at least two valve units with the fault protection function are cascaded among the bridge circuits, the valve control module 800 and the main control module 500 are correspondingly connected with the driving control module 200 one by one, and the valve control module 800 is in communication connection with the main control module 500.

When a certain valve unit fails, the threshold of the clamping unit 300 is reduced by the adjusting unit 400 in the failed valve unit, so that the clamping unit 300 is more easily broken down, the power component 100 connected with the clamping unit 300 is damaged and broken down to be in a short-circuit state, the failed valve unit is in the short-circuit state by sacrificing the power component 100, other normally working valve units are not affected, the failure is prevented from being further expanded, and the reliability is improved. Under the normal working condition, the adjusting unit 400 can improve the threshold value of the clamping unit 300, thereby being beneficial to improving the efficiency of the clamping unit 300, reducing the heat productivity of the clamping unit 300, prolonging the practical life and reliability, and simultaneously improving the threshold value of the clamping unit 300 and being beneficial to improving the direct-current voltage utilization rate of the valve unit. Therefore, by adjusting the threshold value of the clamping unit 300, the use requirement can be met under the conditions of failure and normal operation.

The main control module 500 is connected with the driving control module 200, and the main control module 500 and the valve control module 800 may be connected through optical fiber communication. The valve control module 800 exchanges data with each main control module 500 to coordinate normal operation among a plurality of valve units, so that the whole converter valve can stably and reliably operate.

The main control module 500 and the valve control module 800 may be implemented by a single chip, an FPGA, a DSP, a CPLD, or an embedded chip.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The present invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the present invention, and such equivalent modifications or substitutions are included in the scope defined by the claims of the present application.

Claims (10)

1. Valve unit with failsafe function, characterized by comprising:

a bridge circuit comprising at least two power components (100);

the driving control module (200) is connected with the control end of the power assembly (100);

at least one clamping unit (300), the clamping unit (300) being connected between the power component (100) and the drive control module (200);

at least one adjusting unit (400) connected to the clamping unit (300), wherein the adjusting unit (400) is capable of adjusting a threshold of the clamping unit (300).

2. The fail-safe valve unit according to claim 1, wherein: the clamping unit (300) comprises a switching tube Q1 and a plurality of transient voltage suppression diodes, the transient voltage suppression diodes are connected in series to form a series link (310), the cathode of the series link (310) is connected with the power component (100), the anode of the series link (310) is connected with the control end of the drive control module (200) and/or the power component (100), the adjusting unit (400) is connected with the control end of the switching tube Q1, the switching tube Q1 is connected with the series link (310), and the switching tube Q1 is conducted to enable at least one transient voltage suppression diode to be short-circuited.

3. The fail-safe valve unit according to claim 2, characterized in that: the clamping unit (300) further comprises a diode D13, an anode of the diode D13 is connected with the power component (100), and a cathode of the diode D13 is connected with a cathode of the series link (310).

4. The fail-safe valve unit according to claim 2 or 3, characterized in that: the adjusting unit (400) comprises a switch tube Q2 and a resistor R1, one end of the resistor R1 is connected with the power component (100), the other end of the resistor R1 is connected with the control end of the switch tube Q1 and one end of the switch tube Q2, and the other end of the switch tube Q2 and the control end of the switch tube Q2 are connected with the driving control module (200).

5. The fail-safe valve unit according to claim 2 or 3, characterized in that: the clamping unit (300) further comprises a resistor R11, a capacitor C11 and a resistor R13, wherein one end of the resistor R11 is connected with one end of the capacitor C11 and the anode of the series link (310), the other end of the resistor R11 is connected with the other end of the capacitor C11, the control end of the switching tube Q1 and one end of the resistor R13, and the other end of the resistor R13 is connected with the control end of the power component (100).

6. The fail-safe valve unit according to claim 5, wherein: the clamping unit (300) further comprises a trigger circuit (320), and the control end of the switching tube Q1 is respectively connected with the control end of the power component (100) and the drive control module (200) through the trigger circuit (320).

7. The fail-safe valve unit according to claim 6, wherein: the trigger circuit (320) comprises a resistor R12, a voltage regulator tube ZD11 and a diode D12, wherein one end of the resistor R13 is respectively connected with the drive control module (200) and the control end of the power component (100), the other end of the resistor R13 is respectively connected with one end of the resistor R12 and the cathode of the voltage regulator tube ZD11, the anode of the voltage regulator tube ZD11 is connected with the anode of the diode D12, and the other end of the resistor R12 is respectively connected with the cathode of the diode D12 and the control end of the switch tube Q1.

8. The fail-safe valve unit according to claim 1, wherein: the number of the power assemblies (100) is two, the two power assemblies (100) are connected to form a half-bridge circuit, the number of the clamping units (300) is two, the clamping units (300) are correspondingly connected with the power assemblies (100) one by one, the number of the adjusting units (400) is one, and the clamping units (300) correspondingly connected with the middle and lower tubes of the half-bridge circuit are connected with the adjusting units (400).

9. The fail-safe valve unit according to claim 1, wherein: the number of the power assemblies (100) is four, the four power assemblies (100) are connected to form a full-bridge circuit, the number of the clamping units (300) is four and is connected with the power assemblies (100) in a one-to-one correspondence mode, and the number of the adjusting units (400) is two;

the two clamping units (300) which are correspondingly connected with the two lower tubes in the full-bridge circuit are respectively and correspondingly connected with the adjusting units (400) one by one;

or the two clamping units (300) correspondingly connected with the two upper tubes in the full-bridge circuit are respectively and correspondingly connected with the adjusting unit (400).

10. An inverter valve system, comprising: at least two valve units with fault protection function according to any one of claims 1 to 9, the bridge circuits are cascaded, and the valve control module (800) and the master control module (500) connected with the driving control module (200) in a one-to-one correspondence manner are further included, wherein the valve control module (800) is connected with the master control module (500) in a communication manner.

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