A self-checking circuit for an energy extraction power supply of a flexible DC converter valve

Abstract

The present invention discloses a self-test circuit for a flexible DC converter valve energy supply. The overvoltage self-test circuit collects the supply voltage of the energy supply and compares the supply voltage of the energy supply with a reference voltage. When the supply voltage of the energy supply is greater than the reference voltage, an overvoltage signal is output; the undervoltage self-test circuit collects the supply voltage of the energy supply and compares the supply voltage of the energy supply with a reference voltage. When the supply voltage of the energy supply is less than the reference voltage, an undervoltage signal is output; the control circuit outputs a shutdown signal to the energy supply based on the overvoltage signal, and the shutdown signal is used to control the energy supply to stop working; the information feedback circuit sends the undervoltage signal or the overvoltage signal to the control system of the flexible DC converter, thereby realizing the functions of self-detection of the energy supply status and timely reporting of abnormal status, providing timely and accurate judgment for the protection of the converter valve controller, and reducing the occurrence of failure shutdown events with unknown reasons.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible direct current (DC) power transmission, and in particular to a self-test circuit of a flexible DC converter valve energy-taking power supply. Background Art

[0002] The energy-drawing power supply is a key energy conversion component in the power module of a flexible DC transmission converter valve. Its function is to draw energy from the power module's DC support capacitors, perform internal voltage conversion, and provide operating energy for the power module control board and bypass switch. The stability and reliability of the energy-drawing power supply significantly impact the operating status of the converter valve's power module and are a key factor limiting the reliability of the converter valve's overall system operation. Currently, flexible DC transmission converter valves utilize a DC-DC energy-drawing power supply. This power supply inputs high-voltage DC and outputs medium- and low-voltage DC, achieving wide-range DC input and stable medium- and low-voltage output. However, the power supply's self-detection and fault reporting are ineffective, resulting in numerous unexplained shutdowns of the energy-drawing power supply in applications. Summary of the Invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low effectiveness of self-detection and fault reporting of energy-taking power supply in the prior art, thereby providing a self-detection circuit of a flexible DC converter valve energy-taking power supply.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] An embodiment of the present invention provides a self-test circuit for a flexible DC converter valve energy supply, comprising: a reference circuit, an overvoltage self-test circuit, an undervoltage self-test circuit, a control circuit and an information feedback circuit, wherein the reference circuit, whose first end is connected to the output end of the energy supply, is used to convert the supply voltage of the energy supply into a reference voltage; the overvoltage self-test circuit, whose first end is connected to the output end of the energy supply, whose second end is connected to the second end of the reference circuit, and whose third end is connected to the external power supply, is used to collect the supply voltage of the energy supply and compare the supply voltage of the energy supply with the reference voltage, and output an overvoltage signal when the supply voltage of the energy supply is greater than the reference voltage; the undervoltage self-test circuit, whose first end is connected to the output end of the energy supply, and whose second end is connected to the reference circuit The second end of the control circuit is connected, and the third end is connected to the external power supply. It is used to collect the supply voltage of the energy-taking power supply and compare the supply voltage of the energy-taking power supply with the reference voltage. When the supply voltage of the energy-taking power supply is less than the reference voltage, an undervoltage signal is output; a control circuit, a first end of which is connected to the fourth end of the overvoltage self-detection circuit, and a second end of which is connected to the control end of the energy-taking power supply. It is used to output a shutdown signal to the energy-taking power supply based on the overvoltage signal, and the shutdown signal is used to control the energy-taking power supply to stop working; an information feedback circuit, a first end of which is connected to the fifth end of the overvoltage self-detection circuit, a second end of which is connected to the fourth end of the undervoltage self-detection circuit, and a fourth end of which is connected to the control system of the flexible DC converter. It is used to send an undervoltage signal or an overvoltage signal to the control system of the flexible DC converter.

[0006] In one embodiment, the reference circuit includes: a first diode, a first resistor, a second resistor, a third resistor, a first capacitor and a first voltage-stabilizing diode, wherein the anode of the first diode is connected to the output end of the energy supply, and the cathode of the first diode is respectively connected to the first end of the first resistor and the first end of the second resistor; the first end of the third resistor is respectively connected to the second end of the first resistor, the second end of the second resistor and the first end of the first capacitor, and the second end of the third resistor is connected to the first end of the first voltage-stabilizing diode; the second end of the first capacitor is grounded; the first voltage-stabilizing diode, the first end and the second end of the first voltage-stabilizing diode are both connected to the second end of the overvoltage self-test circuit and the first end of the undervoltage self-test circuit, and the third end is grounded.

[0007] In one embodiment, the overvoltage self-detection circuit includes: an overvoltage acquisition circuit and an overvoltage comparison circuit, wherein the overvoltage acquisition circuit has a first end connected to the output end of the energy taking power supply, and a second end connected to the first end of the overvoltage comparison circuit, and is used to acquire the supply voltage of the energy taking power supply; the overvoltage comparison circuit has a second end connected to the second end of the reference circuit, a third end connected to the external power supply, a fourth end connected to the first end of the control circuit, and a fifth end connected to the first end of the information feedback circuit, and is used to compare the supply voltage of the energy taking power supply with the reference voltage, and output an overvoltage signal when the supply voltage of the energy taking power supply is greater than the reference voltage.

[0008] In one embodiment, the overvoltage comparison circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second diode, a third diode, a fourth diode, and a first comparator, wherein the first comparator has a positive input terminal connected to the second terminal of the overvoltage acquisition circuit through the fifth resistor, a negative input terminal connected to the second terminal of the reference circuit through the fourth resistor, an output terminal connected to the external power supply through the sixth resistor, and an output terminal connected to the anode of the second diode, the anode of the third diode, and the anode of the fourth diode; the second diode has a cathode connected to the first terminal of the information feedback circuit; the third diode has a cathode connected to the first terminal of the control circuit; and the fourth diode has a cathode connected to the positive input terminal of the first comparator through the seventh resistor.

[0009] In one embodiment, the undervoltage self-detection circuit includes: an undervoltage acquisition circuit and an undervoltage comparison circuit, wherein the undervoltage acquisition circuit has a first end connected to the output end of the energy-taking power supply, and a second end connected to the first end of the undervoltage comparison circuit, and is used to acquire the supply voltage of the energy-taking power supply; the undervoltage comparison circuit has a second end connected to the second end of the reference circuit, a third end connected to the external power supply, and a fourth end connected to the second end of the information feedback circuit, and is used to compare the supply voltage of the energy-taking power supply with the reference voltage, and output an undervoltage signal when the supply voltage of the energy-taking power supply is less than the reference voltage.

[0010] In one embodiment, the undervoltage comparison circuit includes: an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a fifth diode, and a second comparator. The second comparator has a positive input terminal connected to the second terminal of the reference circuit via the eighth resistor, a negative input terminal connected to the second terminal of the undervoltage acquisition circuit via the ninth resistor, an output terminal connected to its positive input terminal via the tenth resistor, an output terminal further connected to an external power supply via the eleventh resistor, and an output terminal further connected to the anode of the fifth diode. The fifth diode has a cathode connected to the second terminal of the information feedback circuit.

[0011] In one embodiment, the control circuit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a second capacitor, an optocoupler isolation chip, a first switching tube and a second switching tube, wherein the first switching tube, the control end of which is connected to the fourth end of the overvoltage self-detection circuit through the twelfth resistor, the first end of which is connected to the external power supply through the thirteenth resistor, and the second end of which is connected to the first end of the optocoupler isolation chip; the second end of the optocoupler isolation chip, the third end of which is connected to the external power supply through the fourteenth resistor, and the fourth end of which is grounded; the second switching tube, the control end of which is connected to the third end of the optocoupler isolation chip, and the control end of which is also respectively connected to the first end of the second capacitor and the first end of the fifteenth resistor, the first end of which is connected to the control end of the energy supply, and the second end of which is grounded; the second capacitor, the second end of which is grounded; the fifteenth resistor, the second end of which is grounded.

[0012] In one embodiment, the information feedback circuit includes: an OR gate logic circuit, an isolation circuit, and an optical signal sending circuit, wherein the OR gate logic circuit has a first end connected to the fifth end of the overvoltage self-detection circuit, and a second end connected to the fourth end of the undervoltage self-detection circuit, and is used to perform an OR logic operation on the undervoltage signal and the overvoltage signal; the optical signal sending circuit has a first end connected to the second end of the OR gate logic circuit through the isolation circuit, and a second end connected to the control system of the flexible DC converter, and is used to send the undervoltage signal or the overvoltage signal to the control system of the flexible DC converter.

[0013] In one embodiment, the self-test circuit of the flexible DC converter valve energy supply also includes: a starting self-test circuit, a first end of which is connected to an external power supply, a second end of which inputs the input voltage of the energy supply, and a third end of which is connected to the control end of the energy supply, and is used to collect the input voltage of the energy supply and divide the input voltage of the energy supply to obtain a divided voltage; convert the voltage of the external power supply into a starting reference voltage; compare the divided voltage with the starting reference voltage, and when the divided voltage is less than the starting reference voltage, output a shutdown signal, and the shutdown signal is used to control the shutdown of the energy supply.

[0014] In one embodiment, the startup self-test circuit includes: a voltage acquisition circuit, a voltage comparison circuit and a startup control circuit, wherein the voltage acquisition circuit has a first end connected to an external power supply, a second end inputting an input voltage of the energy taking power supply, and a third end connected to the first end of the voltage comparison circuit, and is used to acquire the input voltage of the energy taking power supply and divide the input voltage of the energy taking power supply to obtain a divided voltage; the voltage comparison circuit has a second end and a third end both connected to the external power supply, and a fourth end connected to the first end of the startup control circuit, and is used to convert the voltage of the external power supply into a startup reference voltage; compare the divided voltage with the startup reference voltage, and output a conduction signal when the divided voltage is less than the startup reference voltage; the startup control circuit has a second end connected to the control end of the energy taking power supply, and is used to be in a conduction state based on the conduction signal, and output a shutdown signal, and the shutdown signal is used to control the shutdown of the energy taking power supply.

[0015] In one embodiment, the voltage acquisition circuit includes: a sixth diode, a seventh diode, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, and a third capacitor, wherein the first end of the seventeenth resistor is respectively connected to the anode of the sixth diode, the cathode of the seventh diode, the first end of the sixteenth resistor, and the first end of the third capacitor, and the second end of the seventeenth resistor is connected to the first end of the eighteenth resistor; the cathode of the sixth diode is connected to the external power supply; the anode of the seventh diode is grounded; the second end of the sixteenth resistor is connected to the external power supply; the second end of the eighteenth resistor is grounded; and the first end of the third capacitor is further connected to the first end of the voltage comparison circuit, and the second end of the third capacitor is grounded.

[0016] In one embodiment, the voltage comparison circuit includes: a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, an eighth diode, a ninth diode, a second voltage-stabilizing diode, and a third comparator, wherein the third comparator has a positive input terminal connected to the first terminal of the second voltage-stabilizing diode and the second terminal of the second voltage-stabilizing diode through the nineteenth resistor, a negative input terminal connected to the third terminal of the voltage acquisition circuit through the twenty-first resistor, an output terminal connected to the cathode of the eighth diode through the twenty-second resistor, an output terminal further connected to the external power supply through the twenty-third resistor, and an output terminal further connected to the anode of the ninth diode; the eighth diode has an anode connected to the positive input terminal of the third comparator; the ninth diode has a cathode connected to the first terminal of the startup control circuit; the second voltage-stabilizing diode has a first terminal further connected to the external power supply through the twentieth resistor, and a third terminal connected to ground.

[0017] In one embodiment, the startup control circuit includes: a fourth capacitor, a twenty-fourth resistor and a third switching tube, wherein the control end of the third switching tube is respectively connected to the first end of the fourth capacitor, the first end of the twenty-fourth resistor, and the fourth end of the voltage comparison circuit, the first end of the third switching tube is connected to the control end of the energy supply, and the second end of the third switching tube is grounded; the second end of the fourth capacitor is grounded; and the second end of the twenty-fourth resistor is grounded.

[0018] The technical solution of the present invention has the following advantages:

[0019] The present invention provides a self-test circuit for the flexible DC converter valve energy supply. The overvoltage self-test circuit collects the supply voltage of the energy supply and compares the supply voltage of the energy supply with a reference voltage. When the supply voltage of the energy supply is greater than the reference voltage, an overvoltage signal is output; the undervoltage self-test circuit collects the supply voltage of the energy supply and compares the supply voltage of the energy supply with a reference voltage. When the supply voltage of the energy supply is less than the reference voltage, an undervoltage signal is output; the control circuit outputs a shutdown signal to the energy supply based on the overvoltage signal, and the shutdown signal is used to control the energy supply to stop working; the information feedback circuit sends the undervoltage signal or the overvoltage signal to the control system of the flexible DC converter, thereby realizing the functions of self-detection of the energy supply status and timely reporting of abnormal status, providing timely and accurate judgment for the protection of the converter valve controller, and reducing the occurrence of fault shutdown events with unknown reasons. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 A composition diagram of a specific example of a self-test circuit for a flexible DC converter valve energy-taking power supply provided in an embodiment of the present invention;

[0022] Figure 2 Specific circuit topology diagrams of the overvoltage self-test circuit and undervoltage self-test circuit provided in the embodiments of the present invention;

[0023] Figure 3 A composition diagram of another specific example of a self-test circuit for a flexible DC converter valve power supply provided by an embodiment of the present invention;

[0024] Figure 4 A composition diagram of another specific example of a self-test circuit for a flexible DC converter valve power supply provided by an embodiment of the present invention;

[0025] Figure 5 A composition diagram of another specific example of a self-test circuit for a flexible DC converter valve power supply provided by an embodiment of the present invention;

[0026] Figure 6 A composition diagram of another specific example of a self-test circuit for a flexible DC converter valve power supply provided by an embodiment of the present invention;

[0027] Figure 7 This is a specific circuit topology diagram of the startup self-test circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components; wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0031] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] Example

[0033] An embodiment of the present invention provides a self-test circuit for a flexible DC converter valve power supply. The flexible DC converter valve power supply is typically composed of a DC-DC power converter, an output filter voltage conversion circuit, a power device driver circuit, and other components. The power device driver circuit is used to drive the power electronic devices within the DC-DC power converter to cause the DC-DC power converter to output a voltage of a corresponding level or stop outputting voltage. The output filter voltage conversion circuit is used to filter the output voltage of the DC-DC power converter. The DC-DC power converter can obtain input high voltage from the DC support capacitor of the flexible DC converter valve power module.

[0034] like Figure 2 As shown, the self-test circuit of the flexible DC converter valve energy-taking power supply includes: a reference circuit 1, an overvoltage self-test circuit 2, an undervoltage self-test circuit 3, a control circuit 4 and an information feedback circuit 5.

[0035] like Figure 2 As shown, the first end of the reference circuit 1 is connected to the output end of the energy-taking power supply, and the reference circuit 1 is used to convert the supply voltage of the energy-taking power supply into a reference voltage; the reference circuit 1 of the embodiment of the present invention can also be implemented using a programmable reference source, and the reference voltage can be set according to actual working conditions, which is not limited here.

[0036] like Figure 2 As shown, the first end of the overvoltage self-detection circuit 2 is connected to the output end of the energy-taking power supply, the second end of the overvoltage self-detection circuit 2 is connected to the second end of the reference circuit 1, and the third end of the overvoltage self-detection circuit 2 is connected to the external power supply. The overvoltage self-detection circuit 2 is used to collect the supply voltage of the energy-taking power supply and compare the supply voltage of the energy-taking power supply with the reference voltage. When the supply voltage of the energy-taking power supply is greater than the reference voltage, an overvoltage signal is output.

[0037] like Figure 2As shown, the first end of the undervoltage self-detection circuit 3 is connected to the output end of the energy-taking power supply, the second end of the undervoltage self-detection circuit 3 is connected to the second end of the reference circuit 1, and the third end of the undervoltage self-detection circuit 3 is connected to the external power supply. The undervoltage self-detection circuit 3 is used to collect the supply voltage of the energy-taking power supply and compare the supply voltage of the energy-taking power supply with the reference voltage. When the supply voltage of the energy-taking power supply is less than the reference voltage, an undervoltage signal is output.

[0038] like Figure 2 As shown, the first end of the control circuit 4 is connected to the fourth end of the overvoltage self-detection circuit 2, and the second end of the control circuit 4 is connected to the control end of the energy supply. The control circuit 4 is used to output a shutdown signal to the energy supply based on the overvoltage signal, and the shutdown signal is used to control the energy supply to stop working.

[0039] Specifically, when the flexible DC converter valve energy supply is mostly composed of a DC-DC power converter, an output filter voltage conversion circuit, a power device driving circuit, etc., the second end of the control circuit 4 is actually connected to the power device driving circuit, and the power device driving circuit controls the power electronic switches and other devices inside the DC-DC power converter to stop working based on the shutdown signal, but the above is only for example and is not limited to this.

[0040] like Figure 2 As shown, the first end of the information feedback circuit 5 is connected to the fifth end of the overvoltage self-detection circuit 2, the second end of the information feedback circuit 5 is connected to the fourth end of the undervoltage self-detection circuit 3, and the fourth end of the information feedback circuit 5 is connected to the control system of the flexible DC converter. The information feedback circuit 5 is used to send an undervoltage signal or an overvoltage signal to the control system of the flexible DC converter.

[0041] Specifically, when the output voltage of the energy-taking power supply is overvoltage or undervoltage, that is, when the information feedback circuit 5 receives an overvoltage signal or an undervoltage signal, the information feedback circuit 5 converts the received signals into optical signals and sends them to the control system of the flexible DC converter. The control system can be a power module controller or a valve controller to serve as input information for judging the status of the energy-taking power supply.

[0042] In a specific embodiment, if Figure 2 As shown, the reference circuit 1 includes: a first diode D1, a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1 and a first voltage regulator Z1.

[0043] like Figure 2 As shown, the anode of the first diode D1 is connected to the output terminal of the energy source ( Figure 2The cathode of the first diode D1 is connected to the first end of the first resistor R1 and the first end of the second resistor R2 respectively; the first end of the third resistor R3 is connected to the second end of the first resistor R1, the second end of the second resistor R2, and the first end of the first capacitor C1 respectively, and the second end of the third resistor R3 is connected to the first end of the first voltage-stabilizing tube Z1; the second end of the first capacitor C1 is grounded; the first end of the first voltage-stabilizing tube Z1 and the second end of the first voltage-stabilizing tube Z1 are both connected to the second end ( Figure 2 The first end of R4 in the circuit), the first end of the undervoltage self-detection circuit 3 ( Figure 2 The third end of the first voltage regulator tube Z1 is grounded.

[0044] Specifically, Figure 2 In the embodiment, the unidirectional conductivity of the first diode D1 can limit the voltage of the self-test circuit to be too large, and the unidirectional conductivity of the first diode D1 can prevent the excessive voltage from being reversely applied to the energy source and damaging the energy source.

[0045] In a specific embodiment, if Figure 3 As shown, the overvoltage self-detection circuit 2 includes: an overvoltage acquisition circuit 21 and an overvoltage comparison circuit 22 .

[0046] like Figure 3 As shown, the first end of the overvoltage acquisition circuit 21 is connected to the output end of the energy-taking power supply, and the second end of the overvoltage acquisition circuit 21 is connected to the first end of the overvoltage comparison circuit 22. The overvoltage acquisition circuit 21 is used to collect the supply voltage of the energy-taking power supply.

[0047] Specifically, the overvoltage acquisition circuit 21 may be a voltage acquisition circuit formed by a voltage transformer, or may be a voltage acquisition circuit formed by a voltage divider circuit, which is not limited here.

[0048] like Figure 3 As shown, the second end of the overvoltage comparison circuit 22 is connected to the second end of the reference circuit 1, the third end of the overvoltage comparison circuit 22 is connected to the external power supply, the fourth end of the overvoltage comparison circuit 22 is connected to the first end of the control circuit 4, and the fifth end of the overvoltage comparison circuit 22 is connected to the first end of the information feedback circuit 5. The overvoltage comparison circuit 22 is used to compare the power supply voltage of the energy-taking power supply with the reference voltage, and output an overvoltage signal when the power supply voltage of the energy-taking power supply is greater than the reference voltage.

[0049] like Figure 2 As shown, the overvoltage comparison circuit 22 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second diode D2, a third diode D3, a fourth diode D4 and a first comparator U1.

[0050] like Figure 2As shown, the positive input terminal of the first comparator U1 is connected to the second terminal of the overvoltage acquisition circuit 21 through the fifth resistor R5, and the negative input terminal of the first comparator U1 is connected to the second terminal of the reference circuit 1 ( Figure 2 The output end of the first comparator U1 is connected to the external power supply ( Figure 2 The output end of the first comparator U1 is connected to the anode of the second diode D2, the anode of the third diode D3, and the anode of the fourth diode D4; the cathode of the second diode D2 is connected to the first end of the information feedback circuit 5; the cathode of the third diode D3 is connected to the first end ( Figure 2 the cathode of the fourth diode D4 is connected to the positive input terminal of the first comparator U1 through the seventh resistor R7.

[0051] Specifically, during the overvoltage self-test process, the reference voltage output by the reference circuit 1 is input to the inverting input terminal of the first comparator U1 after being current-limited by the fourth resistor R4. The supply voltage of the energy taking power supply collected by the overvoltage acquisition circuit 21 is input to the positive input terminal of the first comparator U1 after being current-limited by the fifth resistor R5. The first comparator U1 compares the reference voltage with the supply voltage of the energy taking power supply. When the supply voltage of the energy taking power supply is higher than the reference voltage, the output terminal of the first comparator U1 outputs an overvoltage signal, which is output in three paths through the second diode D2, the third diode D3, and the fourth diode D4. Among them, the second diode D2 sends the overvoltage signal to the signal feedback circuit, which performs photoelectric conversion on the overvoltage signal and sends it to the control system; the third diode D3 transmits the overvoltage signal to the control circuit 4, and the control circuit 4 outputs a shutdown signal to the energy taking power supply based on the overvoltage signal. The shutdown signal is used to control the energy taking power supply to stop working; the fourth diode D4 is connected in series with the seventh resistor R7 to feed the overvoltage signal back to the positive input terminal of the first comparator U1.

[0052] In a specific embodiment, if Figure 4 As shown, the undervoltage self-detection circuit 3 includes: an undervoltage acquisition circuit 31 and an undervoltage comparison circuit 32 .

[0053] like Figure 4 As shown, the first end of the undervoltage acquisition circuit 31 is connected to the output end of the energy-taking power supply, and the second end of the undervoltage acquisition circuit 31 is connected to the first end of the undervoltage comparison circuit 32. The undervoltage acquisition circuit 31 is used to collect the supply voltage of the energy-taking power supply.

[0054] Specifically, the undervoltage acquisition circuit 31 may be a voltage acquisition circuit formed by a voltage transformer, or may be a voltage acquisition circuit formed by a voltage divider circuit, which is not limited here.

[0055] like Figure 4As shown, the second end of the undervoltage comparison circuit 32 is connected to the second end of the reference circuit 1, the third end of the undervoltage comparison circuit 32 is connected to the external power supply, and the fourth end of the undervoltage comparison circuit 32 is connected to the second end of the information feedback circuit 5. The undervoltage comparison circuit 32 is used to compare the supply voltage of the energy-taking power supply with the reference voltage, and output an undervoltage signal when the supply voltage of the energy-taking power supply is less than the reference voltage.

[0056] like Figure 2 As shown, the undervoltage comparison circuit 32 includes an eighth resistor R8 , a ninth resistor R9 , a tenth resistor R10 , an eleventh resistor R11 , a fifth diode D5 and a second comparator U2 .

[0057] like Figure 2 As shown, the positive input terminal of the second comparator U2 is connected to the second terminal ( Figure 2 The inverting input terminal of the second comparator U2 is connected to the second terminal of the undervoltage acquisition circuit 31 through the ninth resistor R9, the output terminal of the second comparator U2 is connected to the positive input terminal thereof through the tenth resistor R10, and the output terminal of the second comparator U2 is also connected to the external power supply ( Figure 2 The output end of the second comparator U2 is also connected to the anode of the fifth diode D5; the cathode of the fifth diode D5 is connected to the second end of the information feedback circuit 5.

[0058] Specifically, during the undervoltage self-test process, the reference voltage output by the reference circuit 1 is input to the positive input terminal of the second comparator U2 after being current limited by the eighth resistor R8. The supply voltage of the energy power supply collected by the undervoltage acquisition circuit 31 is input to the reverse input terminal of the second comparator U2 after being current limited by the third resistor. The second comparator U2 compares the reference voltage with the supply voltage of the energy power supply. When the supply voltage of the energy power supply is lower than the reference voltage, the output terminal of the second comparator U2 outputs an undervoltage signal. The undervoltage signal is output to the signal feedback circuit through the fifth diode D5. The signal feedback circuit performs photoelectric conversion on the undervoltage signal and sends it to the control system.

[0059] Specifically, Figure 2 The tenth resistor R10 and the eleventh resistor R11 form a resistance hysteresis loop of the second comparator U2 to ensure that the initial voltage after the energy source is started is consistent with the locking voltage after it is stopped without large deviation.

[0060] In a specific embodiment, if Figure 2 As shown, the control circuit 4 includes: a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a second capacitor C2, an optocoupler isolation chip U4, a first switch tube T1 and a second switch tube T2.

[0061] like Figure 2 As shown, the control terminal of the first switch tube T1 is connected to the fourth terminal ( Figure 2 The first end of the first switch tube T1 is connected to the external power supply ( Figure 2 The second end of the first switch tube T1 is connected to the first end of the optocoupler isolation chip U4; the second end of the optocoupler isolation chip U4 is grounded, and the third end of the optocoupler isolation chip U4 is connected to the external power supply (Vcc1 end) through the fourteenth resistor R14. Figure 2 The fourth terminal of the optocoupler isolation chip U4 is grounded; the control terminal of the second switch tube T2 is connected to the third terminal of the optocoupler isolation chip U4, and the control terminal of the second switch tube T2 is also connected to the first terminal of the second capacitor C2 and the first terminal of the fifteenth resistor R15 respectively. The first terminal of the second switch tube T2 is connected to the control terminal of the energy supply, and the second terminal of the second switch tube T2 is grounded; the second terminal of the second capacitor C2 is grounded; and the second terminal of the fifteenth resistor R15 is grounded.

[0062] Specifically, when the overvoltage self-detection circuit 2 outputs an overvoltage signal, the overvoltage signal drives the first switch tube T1 to conduct. After passing through the filter network formed by the optocoupler isolation chip U4, the second capacitor C2, and the fifteenth resistor R15, the overvoltage signal is transmitted to the control terminal of the second switch tube T2. At this time, the second switch tube T2 is turned on, and the first terminal of the second switch tube T2 outputs a shutdown signal to the control terminal of the energy source. The shutdown signal is used to control the energy source to stop operating. When the flexible DC converter valve energy source is mostly composed of a DC-DC power converter, an output filter voltage conversion circuit, a power device driver circuit, etc., the shutdown signal is transmitted to the power device driver circuit, causing the power device driver circuit to stop operating and no longer output switching control commands for the power device (e.g., a power electronic switch).

[0063] Specifically, when the overvoltage self-detection circuit 2 does not output an overvoltage signal, the first switch tube T1 is turned off, the second switch tube T2 is turned off, the power device drive circuit operates normally, outputs the power device switch control command, and the energy supply operates normally.

[0064] In a specific embodiment, if Figure 5 As shown, the information reporting circuit 5 includes an OR gate logic circuit 51 , an isolation circuit 52 , and an optical signal sending circuit 53 .

[0065] like Figure 5 As shown, the first end of the OR gate logic circuit 51 is connected to the fifth end of the overvoltage self-detection circuit 2, and the second end of the OR gate logic circuit 51 is connected to the fourth end of the undervoltage self-detection circuit 3. The OR gate logic circuit 51 is used to perform an OR logic operation on the undervoltage signal and the overvoltage signal.

[0066] like Figure 5As shown, the first end of the optical signal sending circuit 53 is connected to the second end of the OR gate logic circuit 51 through the isolation circuit 52, and the second end of the optical signal sending circuit 53 is connected to the control system of the flexible DC converter. The optical signal sending circuit 53 is used to send an undervoltage signal or an overvoltage signal to the control system of the flexible DC converter.

[0067] Specifically, the optical signal sending circuit 53 can be a photoelectric conversion chip, which can convert the undervoltage signal or overvoltage signal into an optical signal and send it to the control system of the flexible DC converter to serve as input information for the controller to determine the energy supply status.

[0068] In a specific embodiment, if Figure 5 As shown, the self-test circuit of the flexible DC converter valve energy-taking power supply also includes:

[0069] like Figure 5 As shown, the first end of the startup self-test circuit 6 is connected to the external power supply, the second end of the startup self-test circuit 6 inputs the input voltage of the energy-taking power supply, and the third end of the startup self-test circuit 6 is connected to the control end of the energy-taking power supply. The startup self-test circuit 6 is used to collect the input voltage of the energy-taking power supply and divide the input voltage of the energy-taking power supply to obtain a divided voltage; convert the voltage of the external power supply into a startup reference voltage; compare the divided voltage with the startup reference voltage, and when the divided voltage is less than the startup reference voltage, output a shutdown signal, and the shutdown signal is used to control the shutdown of the energy-taking power supply. Figure 5 The HV+ end and the HV- end are respectively connected to the two ends of the DC support capacitor of the power module of the flexible DC converter valve.

[0070] Specifically, Figure 5 The energy-taking power supply is composed of a DC-DC power converter, an output filter voltage conversion circuit, and a power device driving circuit as an example. After obtaining the input high voltage from the DC support capacitor of the power module, a stable and easy-to-detect DC voltage is obtained through the anti-reverse, filtering and voltage-equalizing circuits. The DC voltage passes through the starting self-test circuit 6, and the starting self-test circuit 6 determines whether the voltage division of the DC voltage reaches the starting reference voltage. When it is higher than the starting reference voltage, the power device driving circuit works normally and regulates and controls the DC-DC power converter to generate a DC low voltage. When it is lower than the starting reference voltage, the starting self-test circuit 6 outputs a shutdown signal to the power device driving circuit. The power device driving circuit stops outputting control instructions for the power devices inside the DC-DC power converter based on the shutdown signal.

[0071] In a specific embodiment, the startup self-test circuit 6 includes: a voltage acquisition circuit, a voltage comparison circuit and a startup control circuit.

[0072] Specifically, the first end of the voltage acquisition circuit is connected to the external power supply, the second end of the voltage acquisition circuit inputs the input voltage of the energy power supply, and the third end of the voltage acquisition circuit is connected to the first end of the voltage comparison circuit. The voltage acquisition circuit is used to collect the input voltage of the energy power supply and divide the input voltage of the energy power supply to obtain a divided voltage.

[0073] Specifically, if Figure 7 As shown, the voltage acquisition circuit includes: a sixth diode D6, a seventh diode D7, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18 and a third capacitor C3, wherein the first end of the seventeenth resistor R17 is respectively connected to the anode of the sixth diode D6, the cathode of the seventh diode D7, the first end of the sixteenth resistor R16, and the first end of the third capacitor C3, and the second end of the seventeenth resistor R17 is connected to the first end of the eighteenth resistor R18; the cathode of the sixth diode D6 is connected to the external power supply; the anode of the seventh diode D7 is grounded; the second end of the sixteenth resistor R16 is connected to the external power supply; the second end of the eighteenth resistor R18 is grounded; the first end of the third capacitor C3 is also connected to the first end of the voltage comparison circuit ( Figure 7 One end of R21 in the middle is connected, and a second end of the third capacitor C3 is grounded.

[0074] Specifically, Figure 7 In the circuit, the DC support capacitor terminal voltage is input to the VH_IN terminal, and the DC support capacitor terminal voltage is divided by a voltage divider circuit composed of a sixteenth resistor R16, a seventeenth resistor R17, and an eighteenth resistor R18. The third capacitor C3 is connected in parallel with the resistor on the low-voltage side of the voltage divider circuit, thereby obtaining a stable divided voltage on the low-voltage side resistor. The divided voltage is limited by the upper and lower limits of the clamping circuit composed of the sixth diode D6 and the seventh diode D7 to prevent the voltage from exceeding the limit and burning the circuit.

[0075] Specifically, the voltage comparison circuit has its second and third terminals connected to the external power supply, and its fourth terminal connected to the first terminal of the startup control circuit. It is used to convert the voltage of the external power supply into a startup reference voltage; compare the divided voltage with the startup reference voltage, and output a conduction signal when the divided voltage is less than the startup reference voltage.

[0076] Specifically, if Figure 7 As shown, the voltage comparison circuit includes: a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a twenty-third resistor R23, an eighth diode D8, a ninth diode D9, a second voltage regulator Z2, and a third comparator U3, wherein the positive input terminal of the third comparator U3 is connected to the first terminal of the second voltage regulator Z2 and the second terminal of the second voltage regulator Z2 through the nineteenth resistor R19, and the negative input terminal of the third comparator U3 is connected to the third terminal ( Figure 7 The output end of the third comparator U3 is connected to the cathode of the eighth diode D8 via the twenty-second resistor R22. The output end of the third comparator U3 is also connected to the external power supply via the twenty-third resistor R23. The output end of the third comparator U3 is also connected to the anode of the ninth diode D9. The anode of the eighth diode D8 is connected to the positive input end of the third comparator U3. The cathode of the ninth diode D9 is connected to the first end ( Figure 7 a first end of the second voltage regulator Z2 is also connected to the external power supply through the twentieth resistor R20, and a third end thereof is grounded.

[0077] Specifically, Figure 7 In the embodiment of the present invention, the divided voltage is transmitted to the inverting input terminal of the third comparator U3. At the same time, the clamping voltage input from the VCC_VH terminal passes through the voltage stabilizing circuit composed of the twentieth resistor R20, the nineteenth resistor R19 and the second voltage regulator Z2, and then outputs the starting reference voltage to the positive input terminal of the third comparator U3. The third comparator U3 compares the divided voltage with the starting reference voltage. When the divided voltage is lower than the starting reference voltage, the third comparator U3 outputs a conduction signal to the startup control circuit.

[0078] Specifically, Figure 7 In the embodiment, the eighth diode D8 and the twenty-second resistor R22 form a single-phase hysteresis loop to prevent the reference voltage from drifting during the startup and locking process of the energy source.

[0079] Specifically, the second end of the start-up control circuit is connected to the control end of the energy-taking power supply. The start-up control circuit is in an on state based on a conduction signal, and outputs a shutdown signal, which is used to control the shutdown of the energy-taking power supply.

[0080] Specifically, if Figure 7 As shown, the startup control circuit includes: a fourth capacitor C4, a twenty-fourth resistor R24 and a third switch tube T3, wherein the control end of the third switch tube T3 is respectively connected to the first end of the fourth capacitor C4, the first end of the twenty-fourth resistor R24, and the fourth end of the voltage comparison circuit ( Figure 7 A first end of the third switch tube T3 is connected to the control end of the energy source, a second end of the third switch tube T3 is grounded; a second end of the fourth capacitor C4 is grounded; and a second end of the twenty-fourth resistor R24 is grounded.

[0081] Specifically, when the voltage comparison circuit converts the voltage of the external power supply into a starting reference voltage; compares the divided voltage with the starting reference voltage, when the divided voltage is less than the starting reference voltage, the voltage comparison circuit outputs a conduction signal to the starting control circuit, and the conduction signal is filtered through the filter network composed of the fourth capacitor C4 and the twenty-fourth resistor R24 and then transmitted to the control end of the third switch tube T3. At this time, the third switch tube T3 is turned on, and the energy supply stops working. Among them, when the energy supply is composed of a DC-DC power converter, an output filter voltage conversion circuit, and a power device driving circuit, when the third switch tube is turned on, the power device driving circuit is pulled down to ground and stops working, and no longer outputs the power device control command.

[0082] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A self-test circuit for a flexible DC converter valve power supply, characterized in that: include: Reference circuit, overvoltage self-test circuit, undervoltage self-test circuit, control circuit, information feedback circuit and startup self-test circuit, among which, a reference circuit, a first end of which is connected to the output end of the energy-taking power supply, and is used to convert the supply voltage of the energy-taking power supply into a reference voltage; an overvoltage self-detection circuit, wherein a first end of the circuit is connected to the output end of the energy source, a second end of the circuit is connected to the second end of the reference circuit, and a third end of the circuit is connected to the external power supply, and is configured to collect the supply voltage of the energy source and compare the supply voltage of the energy source with the reference voltage, and output an overvoltage signal when the supply voltage of the energy source is greater than the reference voltage; an undervoltage self-detection circuit, a first end of which is connected to the output end of the energy taking power supply, a second end of which is connected to the second end of the reference circuit, and a third end of which is connected to the external power supply, and is used to collect the supply voltage of the energy taking power supply and compare the supply voltage of the energy taking power supply with the reference voltage, and output an undervoltage signal when the supply voltage of the energy taking power supply is less than the reference voltage; a control circuit, a first end of which is connected to the fourth end of the overvoltage self-detection circuit, and a second end of which is connected to the control end of the energy taking power supply, and configured to output a shutdown signal to the energy taking power supply based on the overvoltage signal, wherein the shutdown signal is used to control the energy taking power supply to stop working; an information feedback circuit, a first end of which is connected to the fifth end of the overvoltage self-detection circuit, a second end of which is connected to the fourth end of the undervoltage self-detection circuit, and a fourth end of which is connected to the control system of the flexible DC converter, and configured to send the undervoltage signal or overvoltage signal to the control system of the flexible DC converter; The undervoltage self-detection circuit includes: an undervoltage acquisition circuit and an undervoltage comparison circuit, wherein the undervoltage acquisition circuit has a first end connected to the output end of the energy-taking power supply and a second end connected to the first end of the undervoltage comparison circuit, and is used to acquire the supply voltage of the energy-taking power supply; the undervoltage comparison circuit has a second end connected to the second end of the reference circuit, a third end connected to the external power supply, and a fourth end connected to the second end of the information feedback circuit, and is used to compare the supply voltage of the energy-taking power supply with the reference voltage, and output an undervoltage signal when the supply voltage of the energy-taking power supply is less than the reference voltage; The undervoltage comparison circuit includes: an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a fifth diode, and a second comparator, wherein the second comparator has a positive input terminal connected to the second terminal of the reference circuit through the eighth resistor, a negative input terminal connected to the second terminal of the undervoltage acquisition circuit through the ninth resistor, an output terminal connected to its positive input terminal through the tenth resistor, an output terminal further connected to the external power supply through the eleventh resistor, and an output terminal further connected to the anode of the fifth diode; a fifth diode, a cathode of which is connected to the second terminal of the information feedback circuit to start the self-test circuit, a first terminal of which is connected to the external power supply, a second terminal of which is input with the input voltage of the energy taking power supply, and a third terminal of which is connected to the control terminal of the energy taking power supply, and is used to collect the input voltage of the energy taking power supply and divide the input voltage of the energy taking power supply to obtain a divided voltage; convert the voltage of the external power supply into a starting reference voltage; compare the divided voltage with the starting reference voltage, and output a shutdown signal when the divided voltage is less than the starting reference voltage, wherein the shutdown signal is used to control the shutdown of the energy taking power supply; The startup self-test circuit includes: a voltage acquisition circuit, a voltage comparison circuit and a startup control circuit, wherein the voltage acquisition circuit has a first end connected to an external power supply, a second end inputting the input voltage of the energy-taking power supply, and a third end connected to the first end of the voltage comparison circuit, and is used to acquire the input voltage of the energy-taking power supply and divide the input voltage of the energy-taking power supply to obtain a divided voltage; the voltage comparison circuit has a second end and a third end both connected to the external power supply, and a fourth end connected to the first end of the startup control circuit, and is used to convert the voltage of the external power supply into a startup reference voltage; compare the divided voltage with the startup reference voltage, and output a conduction signal when the divided voltage is less than the startup reference voltage; the startup control circuit has a second end connected to the control end of the energy-taking power supply, and is used to be in a conduction state based on the conduction signal, and output a shutdown signal, and the shutdown signal is used to control the shutdown of the energy-taking power supply; The voltage comparison circuit includes: a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, an eighth diode, a ninth diode, a second voltage-stabilizing diode, and a third comparator, wherein the third comparator has a positive input terminal connected to the first terminal and the second terminal of the second voltage-stabilizing diode through the nineteenth resistor, a negative input terminal connected to the third terminal of the voltage acquisition circuit through the twenty-first resistor, an output terminal connected to the cathode of the eighth diode through the twenty-second resistor, an output terminal further connected to the external power supply through the twenty-third resistor, and an output terminal further connected to the anode of the ninth diode; the eighth diode has an anode connected to the positive input terminal of the third comparator; the ninth diode has a cathode connected to the first terminal of the startup control circuit; the second voltage-stabilizing diode has a first terminal further connected to the external power supply through the twentieth resistor, and a third terminal connected to ground.

2. The self-test circuit of the flexible DC converter valve power supply according to claim 1, characterized in that: The reference circuit includes: a first diode, a first resistor, a second resistor, a third resistor, a first capacitor and a first voltage regulator tube, wherein: a first diode, an anode of which is connected to the output end of the energy-taking power supply, and a cathode of which is connected to the first end of the first resistor and the first end of the second resistor respectively; a third resistor, a first end of which is respectively connected to the second end of the first resistor, the second end of the second resistor, and the first end of the first capacitor, and a second end of which is connected to the first end of the first voltage regulator tube; a first capacitor, a second end of which is grounded; The first voltage-stabilizing diode has a first end and a second end connected to the second end of the overvoltage self-detection circuit and the first end of the undervoltage self-detection circuit, and a third end grounded.

3. The self-test circuit of the flexible DC converter valve power supply according to claim 1, characterized in that: The overvoltage self-detection circuit includes: an overvoltage acquisition circuit and an overvoltage comparison circuit, wherein: an overvoltage acquisition circuit, a first end of which is connected to the output end of the energy-taking power supply, and a second end of which is connected to the first end of the overvoltage comparison circuit, and is used to acquire the supply voltage of the energy-taking power supply; An overvoltage comparison circuit, whose second end is connected to the second end of the reference circuit, whose third end is connected to the external power supply, whose fourth end is connected to the first end of the control circuit, and whose fifth end is connected to the first end of the information feedback circuit, is used to compare the supply voltage of the energy-taking power supply with the reference voltage, and output an overvoltage signal when the supply voltage of the energy-taking power supply is greater than the reference voltage.

4. The self-test circuit of the flexible DC converter valve energy source according to claim 3, characterized in that: The overvoltage comparison circuit includes: a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second diode, a third diode, a fourth diode and a first comparator, wherein: a first comparator, wherein a positive input terminal of the first comparator is connected to the second terminal of the overvoltage acquisition circuit via the fifth resistor, a negative input terminal of the first comparator is connected to the second terminal of the reference circuit via the fourth resistor, an output terminal of the first comparator is connected to the external power supply via the sixth resistor, and an output terminal of the first comparator is connected to the anode of the second diode, the anode of the third diode, and the anode of the fourth diode; a second diode, a cathode of which is connected to the first end of the information feedback circuit; a third diode, a cathode of which is connected to the first end of the control circuit; A fourth diode, a cathode of which is connected to the positive input terminal of the first comparator through the seventh resistor.

5. The self-test circuit of the flexible DC converter valve energy source according to claim 1, characterized in that: The control circuit includes: a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a second capacitor, an optical coupling isolation chip, a first switch tube and a second switch tube, wherein: a first switching tube, a control end of which is connected to the fourth end of the overvoltage self-detection circuit via the twelfth resistor, a first end of which is connected to the external power supply via the thirteenth resistor, and a second end of which is connected to the first end of the optocoupler isolation chip; an optical coupling isolation chip, a second terminal of which is grounded, a third terminal of which is connected to the external power supply via the fourteenth resistor, and a fourth terminal of which is grounded; a second switching tube, a control end of which is connected to the third end of the optocoupler isolation chip, a control end of which is further connected to the first end of the second capacitor and the first end of the fifteenth resistor, a first end of which is connected to the control end of the energy source, and a second end of which is grounded; a second capacitor, a second end of which is grounded; A second end of the fifteenth resistor is grounded.

6. The self-test circuit of the flexible DC converter valve power supply according to claim 1, characterized in that: The information feedback circuit includes: an OR gate logic circuit, an isolation circuit, and an optical signal sending circuit, wherein: an OR gate logic circuit, a first end of which is connected to the fifth end of the overvoltage self-detection circuit, a second end of which is connected to the fourth end of the undervoltage self-detection circuit, and is used to perform an OR logic operation on the undervoltage signal and the overvoltage signal; An optical signal sending circuit, wherein a first end thereof is connected to the second end of the OR gate logic circuit through the isolation circuit, and a second end thereof is connected to the control system of the flexible DC converter, and is used to send the undervoltage signal or overvoltage signal to the control system of the flexible DC converter.

7. The self-test circuit of the flexible DC converter valve energy source according to claim 1, characterized in that: The voltage acquisition circuit includes: a sixth diode, a seventh diode, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor and a third capacitor, wherein: a seventeenth resistor, a first end of which is respectively connected to the anode of the sixth diode, the cathode of the seventh diode, the first end of the sixteenth resistor, and the first end of the third capacitor, and a second end of which is connected to the first end of the eighteenth resistor; a sixth diode, a cathode of which is connected to an external power supply; a seventh diode, the anode of which is grounded; a sixteenth resistor, a second end of which is connected to the external power supply; an eighteenth resistor, a second end of which is grounded; The third capacitor has a first end connected to the first end of the voltage comparison circuit and a second end connected to the ground.

8. The self-test circuit of the flexible DC converter valve energy source according to claim 1, characterized in that: The voltage comparison circuit includes: a nineteenth resistor, a twentieth resistor, a twenty-first resistor, a twenty-second resistor, a twenty-third resistor, an eighth diode, a ninth diode, a second voltage regulator, and a third comparator, wherein: a third comparator, having a positive input terminal connected to the first terminal of the second voltage-stabilizing diode and the second terminal of the second voltage-stabilizing diode through the nineteenth resistor, a negative input terminal connected to the third terminal of the voltage acquisition circuit through the twenty-first resistor, an output terminal connected to the cathode of the eighth diode through the twenty-second resistor, an output terminal further connected to the external power supply through the twenty-third resistor, and an output terminal further connected to the anode of the ninth diode; an eighth diode, an anode of which is connected to the positive input terminal of the third comparator; a ninth diode, a cathode of which is connected to the first end of the startup control circuit; The first end of the second voltage-stabilizing diode is further connected to the external power supply through the twentieth resistor, and the third end thereof is grounded.

9. The self-test circuit of the flexible DC converter valve energy source according to claim 1, characterized in that: The startup control circuit includes: a fourth capacitor, a twenty-fourth resistor and a third switch tube, wherein: a third switching tube, whose control terminal is respectively connected to the first terminal of the fourth capacitor, the first terminal of the twenty-fourth resistor, and the fourth terminal of the voltage comparison circuit, a first terminal of the third switching tube is connected to the control terminal of the energy source, and a second terminal of the third switching tube is grounded; a fourth capacitor, a second end of which is grounded; The second end of the twenty-fourth resistor is grounded.

Images