High-voltage capacitor active bleeder circuit

Abstract

A high-voltage capacitor active bleeder circuit relates to the field of new energy charging, and is characterized in that when a door of high-voltage equipment is opened illegally, a normally open end and a common end of a single-pole double-throw switch are communicated, a base electrode of a triode I is grounded, the emitter voltage of the triode I is higher than that of the base electrode, and the triode I is conducted to control a triode II to be conducted; and meanwhile, a controller of the high-voltage equipment immediately stops working after detecting that the door is opened by using a single-pole double-throw switch, cuts off an input channel of a direct-current high-voltage power supply HVDC at the same time, and then controls a triode III to be conducted and a relay to be closed, so that energy is actively discharged. The functions of automatic active discharge, active discharge combined with an equipment controller and the like are achieved, and the electric shock risk caused by abnormal conditions such as connector falling and illegal cover opening is effectively prevented. When abnormal power failure occurs or the charging head falls off, the controller of the high-voltage equipment is also powered down, and the triode III is conducted; the capacitor I forms a loop through a coil of the relay, drives the relay to be closed, and actively discharges voltage below safety voltage through a main loop of the relay.

Description

Technical Field

[0001] The present invention relates to the field of new energy charging, and in particular to a high-voltage capacitor active discharge circuit. Background Art

[0002] At present, new energy products are widely used, low-carbon, environmentally friendly, green and pollution-free, helping the development of all walks of life and greatly promoting social and economic development. For high-voltage new energy products, their safety performance is particularly important, and reliable response measures are required for various possible failures to ensure the safety of personnel, equipment, etc.

[0003] For many high-voltage devices, there are large-capacity energy storage filter capacitors. When the connector falls off, the machine is shut down abnormally, or the cover is opened illegally, the energy in the capacitor needs to be discharged in time to make it below the safe voltage. Generally, the equipment needs to have passive and active discharge functions. For many devices with external auxiliary power supply or backup auxiliary power supply, the above abnormal conditions can be detected online in real time, and a control circuit can be provided to realize the active discharge function. However, for some devices that can only draw power from the high-voltage side, it is very necessary to realize pure hardware active discharge. Summary of the invention

[0004] In order to overcome the deficiencies of the above technologies, the present invention provides a circuit for realizing automatic active discharge.

[0005] The technical solution adopted by the present invention to overcome the technical problems is: A high-voltage capacitor active discharge circuit, comprising: A single-pole double-throw switch is installed on the door of the high-voltage equipment, with its normally closed end connected to the node and its normally open end grounded. The normally closed end and the common end of the single-pole double-throw switch are connected to the controller of the high-voltage equipment. When the door of the high-voltage equipment is in the open state, the common end of the single-pole double-throw switch is connected to the normally open end; The base of transistor I is connected to the common terminal of the single-pole double-throw switch, the emitter of transistor I is connected to the positive node VC of capacitor I, the other end of capacitor I is grounded, the positive electrode of diode I is connected to one end of resistor VII and one end of resistor V, the other end of resistor VII is grounded, and the other end of resistor V is connected to the normally closed end of the single-pole double-throw switch; Transistor II, whose base is connected to the collector of transistor I; Transistor III, whose base is connected to the controller of the high voltage device, whose collector is grounded, and whose emitter is connected to the emitter of transistor II; The relay has one end of its coil connected to the power supply and the cathode of diode II, the other end of its coil connected to the collector of transistor II and the anode of diode II, one end of its main circuit connected to the DC high voltage power supply HVDC, and the other end of its main circuit grounded.

[0006] Furthermore, it also includes a Zener diode, whose anode is respectively connected to the normally open end of the single-pole double-throw switch and the ground, and whose cathode is connected to the normally closed end of the single-pole double-throw switch.

[0007] Furthermore, it also includes resistor I, resistor II, resistor III and resistor IV, one end of which is connected in series to a DC high-voltage power supply HVDC, and the other ends are respectively connected to a normally closed end of a single-pole double-throw switch and one end of resistor IV, and the other end of resistor IV is grounded.

[0008] Furthermore, it also includes a resistor VIII, one end of which is connected to the collector of the transistor I, and the other end of which is connected to the base of the transistor II.

[0009] Furthermore, it also includes a resistor VI, one end of which is connected to the base of the transistor I, and the other end of which is connected to the common end of the single-pole double-throw switch.

[0010] Furthermore, it also includes a resistor IX, one end of which is connected to the base of the transistor II, and the other end of which is connected to the emitter of the transistor II.

[0011] Furthermore, it also includes a resistor X and a resistor XIV, one end of the resistor X is connected to the base of the transistor III, and the other end is connected to the controller of the high-voltage device, one end of the resistor XIV is connected to the controller of the high-voltage device, and the other end is grounded.

[0012] Furthermore, it also includes a resistor XI, a resistor XII, and a resistor XIII. The other end of the relay main circuit is grounded after being connected in parallel with the resistor XI, the resistor XII, and the resistor XIII.

[0013] Furthermore, it also includes capacitor II and capacitor III, one end of the relay main circuit is respectively connected to the DC high voltage power supply HVDC and one end of the capacitor II and capacitor III connected in parallel, and the other end of the capacitor II and capacitor III connected in parallel is grounded.

[0014] Furthermore, the transistor I is a PNP transistor, the transistor II is an NPN transistor, and the transistor III is a PNP transistor.

[0015] The beneficial effects of the present invention are as follows: when the door of the high-voltage equipment is illegally opened, the normally open end of the single-pole double-throw switch is connected to the common end, the base of transistor I is grounded, the emitter voltage of transistor I is higher than the base, transistor I is turned on and then controls transistor II to be turned on, and at the same time, the controller of the high-voltage equipment stops working immediately after detecting that the door is opened using the single-pole double-throw switch, and at the same time cuts off the input channel of the DC high-voltage power supply HVDC, and then controls transistor III to be turned on, the relay is closed, and the energy is actively discharged. When the high-voltage HVDC loses power, transistor I is turned on and then controls transistor II to be turned on, and the controller of the high-voltage equipment loses power as the DC high-voltage power supply HVDC loses power, transistor III is turned on, the relay is closed, and the energy is actively discharged. The functions of automatic active discharge and active discharge combined with the equipment controller are realized, and the risk of electric shock caused by abnormal situations such as connector falling off and illegal cover opening is effectively prevented. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a circuit structure diagram of the present invention; In the figure, 1. single-pole double-throw switch 2. resistor I 3. resistor II 4. resistor III 5. resistor IV 6. zener diode 7. resistor V 8. resistor VI 9. diode I 10. resistor VII 11. capacitor I 12. transistor I 13. resistor VIII 14. resistor IX 15. diode II 16. transistor II 17. resistor X 18. transistor III 19. relay 20. resistor XI 21. resistor XII 22. resistor XIII 23. capacitor II 24. capacitor III 25. resistor XIV V14. node. DETAILED DESCRIPTION

[0017] The following is combined with Figure 1 The present invention is further described.

[0018] A high-voltage capacitor active discharge circuit, comprising: A single-pole double-throw switch 1 is installed on the door of the high-voltage equipment, with its normally closed end connected to the node V14 and its normally open end grounded. The normally closed end and the common end of the single-pole double-throw switch 1 are connected to the controller of the high-voltage equipment. When the door of the high-voltage equipment is in the open state, the common end of the single-pole double-throw switch 1 is connected to the normally open end. Transistor I 12, a base of which is connected to the common terminal of the single-pole double-throw switch 1, an emitter of which is respectively connected to the positive node VC of the capacitor I 11 and the negative electrode of the diode I 9, the other end of the capacitor I 11 is grounded, the positive electrode of the diode I 9 is respectively connected to one end of the resistor VII 10 and one end of the resistor V 7, the other end of the resistor VII 10 is grounded, and the other end of the resistor V 7 is connected to the normally closed end of the single-pole double-throw switch 1; Transistor II 16, whose base is connected to the collector of transistor I 12; Transistor III 18, whose base is connected to the controller of the high voltage device, whose collector is grounded, and whose emitter is connected to the emitter of transistor II 16; Relay 19, one end of its coil end is connected to the power supply and the negative electrode of diode II 15 respectively, the other end of its coil end is connected to the collector of transistor II 16 and the positive electrode of diode II 15 respectively, one end of its main circuit is connected to the DC high voltage power supply HVDC, and the other end of its main circuit is grounded.

[0019] When the DC high-voltage power supply HVDC is powered on, node V14 charges capacitor I 11 through resistor V 7. When the DC high-voltage power supply HVDC reaches the threshold value of 300V, after the voltage is divided by resistor V 7 and resistor VII 10 and the voltage drop of diode I 9, the base voltage of transistor I 12 is equal to node V14 and is higher than the emitter voltage of transistor I 12. Therefore, transistor I 12 is not turned on, and the base of transistor II 16 has no voltage and is not turned on. After the DC high-voltage power supply HVDC is powered on and reaches the threshold value, the controller of the high-voltage equipment starts to work and controls transistor III 18 to be cut off to prevent the active discharge from being triggered by mistake during normal operation.

[0020] When the DC high-voltage power supply HVDC loses power, the voltage of node V14 and the base voltage of transistor Ⅰ 12 decrease, and the voltage of the DC high-voltage power supply HVDC decreases to 252V. At this time, the emitter of transistor Ⅰ 12 is higher than the base voltage, and transistor Ⅰ 12 is turned on; capacitor Ⅰ 11 controls transistor Ⅱ 16 to turn on through the emitter and collector of transistor Ⅰ 12. For the controller of the high-voltage equipment from the high-voltage self-powered equipment, when the DC high-voltage power supply HVDC loses power abnormally or the charging head falls off, the controller of the high-voltage equipment also loses power, and transistor Ⅲ 18 is turned on; capacitor Ⅰ 11 forms a loop through the coil of relay 19, drives relay 19 to close, and the DC high-voltage power supply HVDC is actively discharged to below the safety voltage through the main circuit of relay 19. If the controller of the high-voltage equipment is a wide-voltage working device or has an independent power supply, it can still work when the DC high-voltage power supply HVDC loses power to the 252V threshold, then the controller can continue to control transistor Ⅲ 18 to cut off, and make the new energy equipment work normally.

[0021] When the door of the high-voltage equipment is illegally opened, the normally open end of the single-pole double-throw switch 1 is connected to the common end, the base of the transistor Ⅰ12 is grounded, the emitter voltage of the transistor Ⅰ12 is higher than the base, the transistor Ⅰ12 is turned on and then controls the transistor Ⅱ 16 to be turned on. At the same time, the controller of the high-voltage equipment stops working immediately after detecting that the door is opened using the single-pole double-throw switch 1, and cuts off the DC high-voltage power supply HVDC input channel at the same time, and then controls the transistor Ⅲ 18 to be turned on, and the relay 19 is closed, and the energy is actively discharged.

[0022] In one embodiment of the present invention, a Zener diode 6 is further included, whose anode is respectively connected to the normally open end and the ground of the single-pole double-throw switch 1, and whose cathode is connected to the normally closed end of the single-pole double-throw switch 1. The Zener diode 6 plays a role in voltage stabilization.

[0023] In one embodiment of the present invention, it also includes resistor I 2, resistor II 3, resistor III 4 and resistor IV 5, one end of which is connected in series with resistor I 2, resistor II 3 and resistor III 4 in sequence and connected to the DC high voltage power supply HVDC, and the other end thereof is respectively connected to the normally closed end of the single-pole double-throw switch 1 and one end of resistor IV 5, and the other end of resistor IV 5 is grounded. Resistor I 2, resistor II 3, resistor III 4 and resistor IV 5 are voltage-dividing resistors, and resistor I 2, resistor II 3, resistor III 4 and resistor IV 5 are connected in series between the DC high voltage power supply HVDC and the ground, and the node V14 is divided by the low-side resistor IV 5. When the DC high-voltage power supply HVDC is powered on, node V14 charges capacitor I 11 through resistor V 7. When the DC high-voltage power supply HVDC reaches a threshold of 300V, it is divided by resistors I 2, II 3, III 4 and IV 5 to form a voltage of about 14V across resistor IV 5. Even if the DC high-voltage power supply HVDC continues to rise, it will be stabilized to about 14V by Zener diode 6. 14V is divided by resistors V 7 and VII 10, and the anode voltage of diode I 9 is 13.13V. After a voltage drop of 0.7V through diode I 9, the positive voltage of capacitor I 11 is 12.43V.

[0024] In one embodiment of the present invention, a resistor VIII 13 is further included, one end of the resistor VIII 13 is connected to the collector of the transistor I 12, and the other end thereof is connected to the base of the transistor II 16. The collector of the transistor I 12 is connected to the transistor II 16 via the resistor VIII 13 to realize on-off control of the transistor II 16.

[0025] In one embodiment of the present invention, a resistor VI 8 is further included, one end of the resistor VI 8 is connected to the base of the transistor I 12, and the other end thereof is connected to the common end of the single-pole double-throw switch 1. The common end of the single-pole double-throw switch 1 and the resistor VI 8 are connected to the base of the transistor I 12 to realize on-off control of the transistor I 12.

[0026] In one embodiment of the present invention, a resistor IX 14 is further included, one end of the resistor IX 14 is connected to the base of the transistor II 16, and the other end of the resistor IX 14 is connected to the emitter of the transistor II 16. The resistor IX 14 is connected between the base and the emitter of the transistor II 15, and is used to control the transistor II 15.

[0027] In one embodiment of the present invention, a resistor X17 and a resistor XIV25 are also included. One end of the resistor X17 is connected to the base of the transistor III18, and the other end thereof is connected to the controller of the high-voltage device. One end of the resistor XIV25 is connected to the controller of the high-voltage device, and the other end thereof is grounded. The resistor X17 plays a current limiting role. The resistor XIV25 is a base pull-down resistor of the transistor III18, and the purpose is to actively shut down without the intervention of the controller. When the power is abnormally cut off, the transistor III18 is turned on by default.

[0028] In one embodiment of the present invention, a resistor XI 20, a resistor XII 21, and a resistor XIII 22 are also included, and the other end of the main circuit of the relay 19 is grounded after the resistors XI 20, XII 21, and XIII 22 are connected in parallel. A capacitor II 23 and a capacitor III 24 are also included, and one end of the main circuit of the relay 19 is respectively connected to the DC high-voltage power supply HVDC and one end of the capacitor II 23 and the capacitor III 24 connected in parallel, and the other end of the capacitor II 23 and the capacitor III 24 connected in parallel are grounded. The DC high-voltage power supply HVDC actively discharges the energy of the energy storage filter capacitor II 23 and the energy storage filter capacitor III 24 to below the safety voltage through the main circuit of the relay 19 and the resistors XI 20, XII 21, and XIII 22. The resistance values ​​of the voltage-dividing resistors Ⅰ 2, Ⅱ 3, Ⅲ 4 and Ⅳ 5 are set according to the high-voltage working threshold of the DC high-voltage power supply HVDC, the undervoltage lockout threshold, and the capacity and charging time of C1; and the capacity of the capacitor Ⅰ 11 is set according to the internal resistance of the relay 19 coil, the resistance value of the resistor Ⅷ 13, and the active discharge time; for example, if the maximum voltage is 1000V, the safety voltage is 60V, and the active discharge time requirement is 1s, then the discharge resistors Ⅺ 20, Ⅻ 21 and ⅩⅢ 22 need to be configured according to the energy storage and the energy storage filter capacitors Ⅱ 23 and Ⅲ 24 so that the energy can be discharged within t=1s, that is, ,in is the resistance value of the discharge resistor Ⅺ 20, is the resistance value of the discharge resistor Ⅻ 21, is the resistance value of the discharge resistor ⅩⅢ 22, is the capacity of capacitor II 23, is the capacity of capacitor III 24.

[0029] It is required that after detecting abnormal power failure or cover opening, the control relay 19 should be closed for at least 1s; select the maximum control voltage V R1 =14V, action voltage V R2 =5V, that is, it can be controlled to close within a time constant, and V R2 ≤0.37* V R1 , the internal resistance of the relay coil is RL =1.2kΩ.

[0030] The capacity of capacitor I 11 is selected according to the following formula: in is the capacitance value of capacitor Ⅰ 11, is the resistance value of resistor VIII 13, It represents the resistance value after the two are connected in parallel.

[0031] In one embodiment of the present invention, the transistor I 12 is a PNP transistor, the transistor II 16 is an NPN transistor, and the transistor III 18 is a PNP transistor.

[0032] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high voltage capacitor active discharge circuit, characterized in that: include: A single-pole double-throw switch (1) is installed on the door of the high-voltage equipment, wherein the normally closed end is connected to the node (V14), and the normally open end is grounded. The normally closed end and the common end of the single-pole double-throw switch (1) are connected to the controller of the high-voltage equipment. When the door of the high-voltage equipment is in an open state, the common end of the single-pole double-throw switch (1) is connected to the normally open end. A transistor I (12), a base of which is connected to the common terminal of the single-pole double-throw switch (1), an emitter of which is respectively connected to the positive node VC of the capacitor I (11) and the negative electrode of the diode I (9), the other end of the capacitor I (11) is grounded, the positive electrode of the diode I (9) is respectively connected to one end of the resistor VII (10) and one end of the resistor V (7), the other end of the resistor VII (10) is grounded, and the other end of the resistor V (7) is connected to the normally closed end of the single-pole double-throw switch (1); Transistor II (16), the base of which is connected to the collector of transistor I (12); A transistor III (18), whose base is connected to the controller of the high voltage device, whose collector is grounded, and whose emitter is connected to the emitter of the transistor II (16); A relay (19) has one end of its coil connected to a power supply and a negative electrode of a diode II (15), and the other end of its coil connected to a collector of a transistor II (16) and a positive electrode of a diode II (15). One end of its main circuit is connected to a high-voltage DC power supply HVDC, and the other end of its main circuit is grounded.

2. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a Zener diode (6), the anode of which is respectively connected to the normally open end of the single-pole double-throw switch (1) and the ground, and the cathode of which is connected to the normally closed end of the single-pole double-throw switch (1).

3. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: The device also includes a resistor I (2), a resistor II (3), a resistor III (4) and a resistor IV (5). One end of the resistor I (2), the resistor II (3) and the resistor III (4) connected in series is connected to a high-voltage DC power supply HVDC, and the other ends are respectively connected to a normally closed end of a single-pole double-throw switch (1) and one end of the resistor IV (5). The other end of the resistor IV (5) is grounded.

4. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a resistor VIII (13), one end of which is connected to the collector of the transistor I (12), and the other end of which is connected to the base of the transistor II (16).

5. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a resistor VI (8), one end of which is connected to the base of the transistor I (12), and the other end of which is connected to the common end of the single-pole double-throw switch (1).

6. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a resistor IX (14), one end of which is connected to the base of the transistor II (16), and the other end of which is connected to the emitter of the transistor II (16).

7. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a resistor X (17) and a resistor XIV (25), one end of the resistor X (17) is connected to the base of the transistor III (18), and the other end thereof is connected to the controller of the high-voltage device, and one end of the resistor XIV (25) is connected to the controller of the high-voltage device, and the other end thereof is grounded.

8. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: It also includes a resistor XI (20), a resistor XII (21), and a resistor XIII (22). The other end of the main circuit of the relay (19) is grounded after passing through the resistors XI (20), XII (21), and XIII (22) connected in parallel.

9. The high voltage capacitor active discharge circuit according to claim 8, characterized in that: It also includes a capacitor II (23) and a capacitor III (24), one end of the main circuit of the relay (19) is respectively connected to a DC high voltage power supply HVDC and one end of the capacitor II (23) and the capacitor III (24) connected in parallel, and the other end of the capacitor II (23) and the capacitor III (24) connected in parallel is grounded.

10. The high voltage capacitor active discharge circuit according to claim 1, characterized in that: The transistor I 12 is a PNP transistor, the transistor II 16 is an NPN transistor, and the transistor III 18 is a PNP transistor.

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