CN212163164U

CN212163164U - Special switching power supply for high-voltage power line capacitance power taking

Info

Publication number: CN212163164U
Application number: CN202020749500.6U
Authority: CN
Inventors: 刘爱国
Original assignee: Wuhan Cintonle Power Supply Technology Co ltd
Current assignee: Wuhan Cintonle Power Supply Technology Co ltd
Priority date: 2020-05-08
Filing date: 2020-05-08
Publication date: 2020-12-15
Anticipated expiration: 2030-05-08

Abstract

The utility model provides a special switching power supply is got to high voltage power line capacitance, including surge voltage clamp circuit, current limiting circuit, three-phase four-wire full wave rectifier circuit, EMI filter circuit, power factor correction and tank circuit, power compensation circuit, PWM transform switch circuit, VCC supply circuit, overvoltage crowbar, PWM control circuit, output voltage conversion and rectification filter circuit, output voltage feedback closed-loop control circuit, AC voltage loses electric signal circuit, output filter circuit, super capacitor charging circuit, super capacitor discharge circuit, lose electric signal isolating circuit. The utility model has the advantages that: the power supply can bear 10 times of rated input voltage, is not easy to damage and can automatically recover; the circuit can automatically charge and discharge the external super capacitor, and the integration level is high; due to the high power factor and small reactive power, the VA power of the capacitor PT can be utilized to the maximum extent.

Description

Special switching power supply for high-voltage power line capacitance power taking

Technical Field

The utility model relates to a switching power supply equipment especially relates to a special switching power supply is got to high voltage power line electric capacity.

Background

The power supply of the column switch is mainly powered by an electromagnetic PT and is converted into stable direct current output through the switch power supply, when the high voltage of the electromagnetic PT exists on the high-voltage side, the magnetic core is easily saturated, and the PT is burnt by overlarge current, so that the column switch is not suitable for the power grid environment with large voltage fluctuation.

The capacitive PT power-taking mode is matched with reactance by means of capacitive voltage division to obtain a stable alternating voltage which can bear an environment which is nearly 10 times of a rated voltage, but the apparent power of the capacitive PT power-taking mode is not large due to the fact that capacitive coupling current is not large.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a high voltage power line capacitance gets special switching power supply is the switching power supply of high power factor, high efficiency, the high input voltage who designs for the electric installation is got to capacitanc PT, can carry out the charge-discharge to reserve super capacitor automatically.

The utility model provides a special switching power supply is got to high voltage power line capacitance, including surge voltage clamp circuit (1), current-limiting circuit (2), three-phase four-wire full wave rectifier circuit (3), EMI filter circuit (4), power factor correction and energy storage circuit (5), PWM transform switch circuit (7), output voltage conversion and rectification filter circuit (11), output filter circuit (14), super capacitor charging circuit (15) and super capacitor discharge circuit (16), wherein:

the surge voltage clamping circuit (1) is connected with a high-voltage power grid, alternating current is subjected to current limitation through the current limiting circuit (2), and the alternating current is converted through the three-phase four-wire full-wave rectifying circuit (3) to form direct current pulsating voltage and is input to the EMI filtering circuit (4) to isolate a primary high-frequency interference signal; then, the direct current pulsating voltage is subjected to energy storage through the power factor correction and energy storage circuit (5), and the input current and the output voltage of the power factor correction and energy storage circuit (5) are ensured to be synchronous;

the PWM conversion switching circuit (7) performs high-frequency voltage rectangular wave control on the output voltage according to a PWM control signal and outputs a rectangular voltage wave; the output voltage conversion and rectification filter circuit (11) transforms and rectifies and filters the rectangular voltage wave to obtain stable direct-current voltage; the direct-current voltage is smoothed by the output filter circuit (14) and is output to the super capacitor charging circuit (15) and the super capacitor discharging circuit (16);

the super capacitor charging circuit (15) utilizes the output direct current voltage to charge an external super capacitor in a constant current mode, and the super capacitor discharging circuit (16) is provided with a super capacitor positive electrode connector and a super capacitor negative electrode connector and used for being connected with the external super capacitor, supplying power to an external load and limiting discharging current.

Further, the power factor correction and energy storage circuit (5) comprises a first filter capacitor E1, a second filter capacitor E2, a third filter capacitor E3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D9, a second diode D10, a third diode D11, a fourth diode D12, a fifth diode D13 and a sixth diode D14, wherein the cathode of the first filter capacitor E1 is connected to the cathode of the first diode D9, the anode thereof is connected to one of the output terminals of the EMI filter circuit (4), and the anode of the first diode D9 is connected to the ground and to the other output terminal of the EMI filter circuit (4); the anode of the second filter capacitor E2 is connected to the anode of the third diode D11, the cathode thereof is connected to the cathode of the fourth diode D12, the cathode of the third diode D11 is connected to the anode of the first filter capacitor E1, and the anode of the fourth diode D12 is connected to the anode of the first diode D9; the anode of the third filter capacitor E3 is connected to the anode of the sixth diode D14, the cathode thereof is connected to the anode of the first diode D9, and the cathode of the sixth diode D14 is connected to the anode of the first filter capacitor E1; the anode of the second diode D10 is connected with the cathode of the first filter capacitor E1, and the cathode of the second diode D10 is connected with the anode of the second filter capacitor E2; the anode of the fifth diode D13 is connected with the cathode of the second filter capacitor E2, and the cathode of the fifth diode D13 is connected with the anode of the third filter capacitor E3; the first resistor R1 and the second resistor R2 are connected in series and then connected in parallel to two ends of the first filter capacitor E1, and the third resistor R3 and the fourth resistor R4 are connected in series and then connected in parallel to two ends of the second filter capacitor E2;

the PWM conversion switch circuit (7) comprises a first capacitor C4, a seventh diode D15, a MOS tube Q1, a fifth resistor R14, a sixth resistor R16 and a seventh resistor R17, wherein the source of the MOS tube Q1 is grounded through the seventh resistor R17 on one hand, and is connected with the gate of the MOS tube Q1 through the fifth resistor R14 on the other hand, the drain of the MOS tube Q1 is connected with the output voltage conversion and rectification filter circuit (11) on the one hand, and is connected with the anode of the seventh diode D15 on the other hand, and the cathode of the seventh diode D15 is connected with the anode of the first filter capacitor E1 through the sixth resistor R16 and the first capacitor C4;

the output voltage conversion and rectification filter circuit (11) comprises a transformer T1, an eighth diode D18, a second capacitor C7, an eighth resistor R24, a fourth filter capacitor E5 and a third capacitor CY1, a third pin of the transformer T1 is connected with the drain electrode of the MOS transistor Q1 in the PWM conversion switch circuit (7), a fifth pin of the transformer T1 is connected with a tenth pin of the transformer through a third capacitor CY1, a sixth pin of the transformer T1 is connected with the anode of the fourth filter capacitor E5 after being connected with the second capacitor C7 and the eighth resistor R24 in series, and a seventh pin of the transformer T1 is also connected with the anode of the fourth filter capacitor E5 after being connected with the eighth diode D18 in series; both ends of the fourth filter capacitor E5 are connected with the output filter circuit (14);

the output filter circuit (14) comprises a first inductor L2 and a fifth filter capacitor E6, one end of the first inductor L2 is connected with the anode of the fourth filter capacitor E5, the other end of the first inductor L2 is connected with a connector Vo and the anode of the fifth filter capacitor E6, and the cathode of the fifth filter capacitor E6 is connected with a connector Go and the cathode of the fourth filter capacitor E5;

the super-capacitor charging circuit (15) comprises a power chip U4, a ninth diode D20, a sixth filter capacitor E7, a second inductor L1, a fourth capacitor C10, a fifth capacitor C11, a sixth capacitor C12, a ninth resistor R30, a tenth resistor R31, an eleventh resistor R32 and a twelfth resistor R33, wherein an eighth pin VIN of the power chip U4 is connected with the anode of the filter capacitor E5, a seventh pin VC is connected with the anode of the fifth filter capacitor E6 through the fifth capacitor C11, and the sixth capacitor C12 is connected in parallel with two ends of the fifth filter capacitor E6; a fifth pin CS of the power chip U4 is connected to a negative electrode of the fifth filter capacitor E6 through the eleventh resistor R32 and the twelfth resistor R33, a fourth pin FB is connected to the super capacitor discharging circuit (16) through the ninth resistor R30 and the tenth resistor R31, a second pin SW is connected to one end of the second inductor L1, the other end of the second inductor L1 is connected to a positive electrode of the sixth filter capacitor E7, a negative electrode of the sixth filter capacitor E7 is connected to a negative electrode of the fourth filter capacitor E5 on the one hand, and is connected to the second inductor L1 through the ninth diode D20 on the other hand, the fourth capacitor C10 is connected in parallel to both ends of the sixth filter capacitor E7, and a positive electrode of the sixth filter capacitor E7 is further connected to the super capacitor discharging circuit (16);

the super capacitor discharge circuit (16) comprises a thermistor RT1 and a twelfth diode D19, wherein the anode of the twelfth diode D19 is connected with the anode of the sixth filter capacitor E7, the cathode of the twelfth diode D19 is connected with the anode of the fifth filter capacitor E6, one end of the thermistor RT1 is connected with the cathode of the fifth filter capacitor E6 through the twelfth resistor R33, the other end of the thermistor RT1 is connected with a super capacitor cathode connector C-, and the anode of the twelfth diode D19 is also connected with a super capacitor anode connector C +.

The power factor correction and energy storage circuit further comprises a power compensation circuit (6) which is used for compensating current sampling in high-voltage input and keeping an overload point stable, the power compensation circuit is formed by sequentially connecting a plurality of resistors with the same type in series, one end of the power compensation circuit (6) is connected with the anode of the first filter capacitor E1 in the power factor correction and energy storage circuit (5), and the other end of the power compensation circuit is connected with the source electrode of the MOS transistor Q1 in the PWM conversion switching circuit (7) through a thirteenth resistor R15.

Furthermore, the direct current voltage stabilizing circuit further comprises a PWM control circuit (10), an overvoltage protection circuit (9) and an output voltage feedback closed-loop control circuit (12), wherein the overvoltage protection circuit (9) is connected with the power factor correction and energy storage circuit (5) and is used for monitoring the input voltage of the power factor correction and energy storage circuit (5), the output voltage feedback closed-loop control circuit (12) is connected with the output voltage conversion and rectification filter circuit (11) and is used for sampling the output direct current voltage and generating a feedback signal according to the sampling result and inputting the feedback signal into the PWM control circuit (10), the PWM control circuit (10) outputs and modulates a PWM control signal according to the current sampling, the input voltage detected by the overvoltage protection circuit (9) and the feedback signal from the output voltage feedback closed-loop control circuit (12), so that the finally output direct current voltage is kept stable, wherein:

the PWM control circuit (10) comprises a PWM control chip U1, a seventh capacitor C2, an eighth capacitor C5 and a fourteenth resistor R13, wherein a first pin FS of the PWM control chip U1 is grounded through the eighth capacitor C5, a fourth pin GATE is connected with a grid electrode of a MOS tube Q1 in the PWM conversion switching circuit (7) through the fourteenth resistor R13, a fifth pin CS is grounded through the seventh capacitor C2, a sixth pin PRO is connected with the overvoltage protection circuit (9), a seventh pin GND is grounded, and an eighth pin FB is connected with the output voltage feedback closed-loop control circuit (12);

the overvoltage protection circuit (9) comprises a ninth capacitor C3, a fifteenth resistor R5, a sixteenth resistor R6 and a seventeenth resistor R35, wherein one end of the seventeenth resistor R35 is connected to the sixth pin PRO of the PWM control chip U1, the other end of the seventeenth resistor R35 is grounded, and the ninth capacitor C3 is connected in parallel to the seventeenth resistor R35; the seventeenth resistor R35 is connected with one end of the PWM control chip U1 and is also connected with the anode of the third filter capacitor E3 in the power factor correction and energy storage circuit (5) through the sixteenth resistor R6 and the fifteenth resistor R5;

the output voltage feedback closed-loop control circuit (12) comprises a voltage reference source U3 and a first optical coupler U2, wherein one input end of the first optical coupler U2 is connected with the positive electrode of the fourth filter capacitor E5 in the output voltage conversion and rectification filter circuit (11), the other input end of the first optical coupler U2 is connected with the second output end of the voltage reference source U3 through an eighteenth resistor R23, and the input end of the voltage reference source U3 is connected with the negative electrode of the fourth filter capacitor E5; the anode of the fourth filter capacitor E5 is further connected to the second output terminal of the voltage reference source U3 through a nineteenth resistor R25, and connected to the first output terminal of the voltage reference source U3 through a twentieth resistor R27 and a twenty-first resistor R28; the first output end of the voltage reference source U3 is also connected with the second output end thereof through a tenth capacitor C8 and a twenty-second resistor R26, and is connected with the input end thereof through a twenty-third resistor R29; one output end of the first optical coupler U2 is grounded, and the other output end of the first optical coupler U2 is grounded through an eleventh capacitor C6 and is also connected with an eighth pin FB of the PWM control circuit (10).

Furthermore, the power supply circuit further comprises a VCC power supply circuit (8), wherein the VCC power supply circuit (8) is connected with a PWM control circuit (10) and the output voltage conversion and rectification filter circuit (11), and the DC voltage transformed by the output voltage conversion and rectification filter circuit (11) is used for supplying power to the PWM control circuit (10); the VCC power supply circuit 8 comprises a seventh filter capacitor E4, an eleventh diode D16, and a plurality of resistors connected in series, wherein an anode of the eleventh diode D16 is connected to the first pin of the transformer T1, a cathode of the eleventh diode D16 is connected to the anode of the seventh filter capacitor E4, and a cathode of the seventh filter capacitor E4 is grounded; one end of the plurality of resistors connected in series is connected with the fifth pin of the transformer T1, and the other end of the plurality of resistors is connected with the anode of the seventh filter capacitor E4; the anode of the seventh filter capacitor E4 is also connected to the second pin VCC of the PWM control chip U1.

Further, still include alternating voltage power loss signal circuit (13), power loss signal isolation circuit (17), wherein, alternating voltage power loss signal circuit (13) connect output voltage conversion and rectification filter circuit (11), obtain power loss signal, and convey to power loss signal isolation circuit (17), power loss signal isolation circuit (17) pass through the joint with the power loss signal transmission to external control circuit, wherein:

the alternating voltage power-off signal circuit (13) comprises a twelfth diode D17 and a twelfth capacitor C9, wherein the anode of the twelfth diode D17 is connected with the sixth pin and the seventh pin of the transformer T1, and the cathode of the twelfth diode D17 is connected with the power-off signal isolation circuit (17); one end of the twelfth capacitor C9 is connected to the cathode of the twelfth diode D17, and the other end is connected to the cathode of the fifth filter capacitor E6;

the power-loss signal isolation circuit (17) comprises a second optical coupler U5 and a twenty-fourth resistor R34, wherein one input end of the second optical coupler U5 is connected with the cathode of the twelfth diode D17 through the twenty-fourth resistor R34, the other input end of the second optical coupler U5 is connected with the cathode of the fifth filter capacitor E6, and two output ends of the second optical coupler U5 are respectively connected with a connector COM and a connector POW 1.

Furthermore, the surge voltage clamping circuit (1) consists of four piezoresistors, one end of each piezoresistor is connected with a three-phase four-wire high-voltage power grid, and the other end of each piezoresistor is connected with one end of the other three piezoresistors, which is not connected with the high-voltage power grid; the current limiting circuit (2) consists of four current limiting resistors, one ends of the four current limiting resistors are connected with a high-voltage power grid, and the other ends of the four current limiting resistors are connected with the three-phase four-wire full-wave rectifying circuit (3); the three-phase four-wire full-wave rectifying circuit (3) consists of eight high-voltage diodes to form a full-wave rectifying circuit, and a current-limiting resistor is connected between every two high-voltage diodes which are connected in the same direction; the EMI filter circuit (4) is composed of a thirteenth capacitor C1 and a third inductor LB1, two input ends of the third inductor LB1 are connected with two output ends of the three-phase four-wire full-wave rectifying circuit (3), and two output ends of the third inductor LB1 are connected with the power factor correction and energy storage circuit (5), wherein the output end corresponding to the input end of the third inductor LB1 connected with the cathode of the high-voltage diode is connected with the anode of the first filter capacitor E1, and the output end corresponding to the input end connected with the anode of the high-voltage diode is connected with the anode of the first diode D9; the thirteenth capacitor C1 is connected in parallel to the input terminal of the third inductor LB 1.

The utility model provides a beneficial effect that technical scheme brought is: the power supply can bear 10 times of rated input voltage, is not easy to damage and can automatically recover; the circuit can automatically charge and discharge the external super capacitor, and the integration level is high; due to the high power factor and small reactive power, the VA power of the capacitor PT can be utilized to the maximum extent.

Drawings

Fig. 1 is a schematic structural diagram of a switching power supply dedicated for high-voltage power line capacitance power taking provided by an embodiment of the present invention;

fig. 2 is a partial circuit diagram of a switching power supply dedicated for high-voltage power line capacitance power taking provided by an embodiment of the present invention;

fig. 3 is a circuit diagram of an output voltage portion of the high-voltage power line capacitor power-taking dedicated switching power supply provided by the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be further described below with reference to the accompanying drawings.

Please refer to fig. 1, an embodiment of the present invention provides a high voltage power line capacitor power-taking special switching power supply, which comprises a surge voltage clamping circuit 1, a current limiting circuit 2, a three-phase four-wire full-wave rectifying circuit 3, an EMI filter circuit 4, a power factor correction and energy storage circuit 5, a power compensation circuit 6, a PWM conversion switch circuit 7, a VCC power supply circuit 8, an overvoltage protection circuit 9, a PWM control circuit 10, an output voltage conversion and rectification filter circuit 11, an output voltage feedback closed-loop control circuit 12, an ac voltage power-off signal circuit 13, an output filter circuit 14, a super capacitor charging circuit 15, a super capacitor discharging circuit 16, and a power-off signal isolation circuit 17.

Referring to fig. 2, the surge voltage clamping circuit 1 is connected to a three-phase four-wire system high voltage power grid, and is formed by connecting four voltage dependent resistors RV1, RV2, RV3 and RV4 in series, and when the input voltage is too high, the voltage dependent resistors clamp the voltage at a set value, thereby preventing the high voltage from damaging the subsequent circuit. The current limiting circuit 2 is composed of four current limiting resistors RX1, RX2, RX3 and RX4, one ends of the four current limiting resistors are connected with a high-voltage power grid, and the other ends of the four current limiting resistors are connected with the three-phase four-wire full-wave rectifying circuit 3 to limit the line current. The three-phase four-wire full-wave rectifying circuit 3 comprises a full-wave rectifying circuit consisting of eight high-voltage diodes D1, D2, D3, D4, D5, D6, D7 and D8, a current-limiting resistor is connected between every two high-voltage diodes which are connected in the same direction, four-wire alternating-current voltage is converted into double-wire direct-current pulsating voltage and is transmitted to an EMI filter circuit 4, the EMI filter circuit 4 consists of an inductor LB1 and a capacitor C1 which is connected in parallel to the input end of the inductor LB1, and the direct-current pulsating voltage is transmitted to a power factor correction and energy storage circuit 5 after high-frequency interference signals are isolated.

The power factor correction and energy storage circuit 5 comprises filter capacitors E1, E2 and E3, resistors R1, R2, R3 and R4, diodes D9, D10, D11, D12, D13 and D14, wherein the cathode of the filter capacitor E1 is connected with the cathode of the diode D9, the anode of the filter capacitor E1 is connected with the output end corresponding to the input end connected with the cathode of the high-voltage diode in the inductor LB1, and the anode of the diode D9 is connected with the other output end of the inductor LB 1; the anode of the filter capacitor E2 is connected with the anode of the diode D11, the cathode of the diode D12 is connected with the cathode of the diode D11, the cathode of the diode D11 is connected with the anode of the filter capacitor E1, and the anode of the diode D12 is connected with the anode of the diode D9; the anode of the filter capacitor E3 is connected with the anode of the diode D14, the cathode of the filter capacitor E3 is connected with the anode of the diode D9, and the cathode of the diode D14 is connected with the anode of the filter capacitor E1; the anode of the diode D10 is connected with the cathode of the filter capacitor E1, and the cathode of the diode D10 is connected with the anode of the filter capacitor E2; the anode of the diode D13 is connected with the cathode of the filter capacitor E2, and the cathode of the diode D13 is connected with the anode of the filter capacitor E3; the resistor R1 and the resistor R2 are connected in series and then connected in parallel at two ends of the filter capacitor E1, and the resistor R3 and the resistor R4 are connected in series and then connected in parallel at two ends of the filter capacitor E2.

The power compensation circuit 6 is formed by sequentially connecting a plurality of resistors R7, R8, R9, R10, R11 and R12 of the same type in series, and is used for compensating current sampling during high-voltage input so as to keep an overload point stable, wherein the resistor R7 is connected with the anode of the filter capacitor E1, and the resistor R12 is connected with the PWM conversion switch circuit 7 through a resistor R15.

The PWM conversion switch circuit 7 includes a capacitor C4, a diode D15, a MOS transistor Q1, a resistor R14, R15, R16, and R17, wherein a source of the MOS transistor Q1 is grounded through the resistor R17, and is connected to a gate of the MOS transistor Q1 through the resistor R14; the drain of the MOS transistor Q1 is connected to the output voltage converting and rectifying filter circuit 11, and to the anode of the diode D15, and the cathode of the diode D15 is connected to the anode of the filter capacitor E1 through the resistor R16 and the capacitor C4; the gate of the MOS transistor Q1 is further connected to the PWM control circuit 10, one end of the resistor R15 is connected to the source of the MOS transistor Q1, and the other end is connected to the power compensation circuit 6.

The output voltage conversion and rectification filter circuit 11 comprises a transformer T1, a diode D18, a capacitor C7, a resistor R24, a filter capacitor E5 and a capacitor CY1, wherein the transformer T1 transforms a rectangular voltage wave obtained in the PWM conversion switch circuit 7, a first pin of the transformer T1 is connected with the VCC power supply circuit 8, a second pin of the transformer T1 is grounded, a third pin of the transformer T1 is connected with a drain of a MOS transistor Q1 in the PWM conversion switch circuit 7, a fifth pin of the transformer T1 is connected with the VCC power supply circuit 8 on one hand, and on the other hand, the fifth pin of the transformer T1 is connected with a tenth pin of the capacitor CY1 on the other; a sixth pin of the transformer T1 is connected in series with the capacitor C7 and the resistor R24 and then connected to the anode of the filter capacitor E5, a seventh pin is connected in series with the diode D18 and then connected to the anode of the filter capacitor E5, the sixth pin and the seventh pin output signals after voltage transformation, and the signals are transmitted to the ac voltage loss signal circuit 13 on the one hand and transmitted to the output filter circuit 14 after being filtered by the diode D18, the capacitor C7, the resistor R24 and the filter capacitor E5 on the other hand.

The VCC power supply circuit 8 consists of a filter capacitor E4, a diode D16, and a plurality of resistors R18, R19, R20, R21 and R22 of the same type, wherein the anode of the diode D16 is connected with the first pin of the transformer T1, the cathode of the diode D16 is connected with the anode of the filter capacitor E4, and the cathode of the filter capacitor is grounded; one end of the resistor R18 is connected with a fifth pin of the transformer T1, and the other end of the resistor R18 is connected with the anode of the filter capacitor E4 after being sequentially connected with resistors R19, R20, R21 and R22 in series; the positive electrode of the filter capacitor E4 is further connected to the PWM control circuit 10 for supplying power to the PWM control circuit 10.

The PWM control circuit 10 includes a PWM control chip U1, a capacitor C2, a capacitor C5, and a resistor R13, wherein a first pin FS of the PWM control chip U1 is grounded through a capacitor C5, and a second pin VCC is an input voltage pin and is connected to the positive electrode of a filter capacitor E4 in the VCC power supply circuit 8; a fourth pin GATE of the PWM control chip U1 is connected with the grid electrode of an MOS tube Q1 in the PWM conversion switching circuit 7 through a resistor R13, outputs a PWM control signal, and controls the high-frequency voltage rectangular wave through the turn-off and turn-on of the MOS tube Q1; the fifth pin CS of the PWM control chip U1 is grounded through a capacitor C2, the sixth pin PRO is connected to the overvoltage protection circuit 9, the seventh pin GND is grounded, and the eighth pin FB is a feedback pin and is connected to the output voltage feedback closed-loop control circuit 12.

The overvoltage protection circuit 9 comprises a capacitor C3, a resistor R5, a resistor R6 and a resistor R35, wherein one end of the resistor R35 is connected with the sixth pin PRO of the PWM control chip U1, the other end of the resistor R35 is grounded, and the capacitor C3 is connected in parallel to the resistor R35; the resistor R35 is connected with one end of the PWM control chip U1 and is also connected with the anode of a filter capacitor E3 in the power factor correction and energy storage circuit 5 through a resistor R6 and a resistor R5, and is used for detecting the input voltage of the power factor correction and energy storage circuit 5.

The output voltage feedback closed-loop control circuit 12 comprises a voltage reference source U3, an optical coupler U2, a capacitor C6, a capacitor C8, and a plurality of resistors R23, R25, R26, R27, R28 and R29 of the same type, wherein one input end of the optical coupler U2 is connected with the anode of a filter capacitor E5 in the output voltage conversion and rectification filter circuit 11 to sample the output voltage, the other input end of the optical coupler U2 is connected with the second output end of the voltage reference source U3 through a resistor R23, the input end of the voltage reference source U3 is connected with the cathode of a filter capacitor E5, the anode of the filter capacitor E5 is also connected with the second output end of the voltage reference source U3 through a resistor R25, and is connected with the first output end of the voltage reference source U3 through a resistor R27 and a resistor R28; the first output end of the voltage reference source U3 is also connected with the second output end thereof through a capacitor C8 and a resistor R26, and is connected with the input end thereof through a resistor R29; one output end of the optocoupler U2 is grounded, and the other output end of the optocoupler U2 is grounded through the capacitor C6 and is also connected with an eighth pin FB of the PWM control circuit 10, so that a sampling result is transmitted to the PWM control chip U1 to ensure the stability of the output voltage.

Referring to fig. 3, the output filter circuit 14 includes an inductor L2 and a filter capacitor E6, wherein one end of the inductor L2 is connected to the anode of the filter capacitor E5 in the output voltage converting and rectifying filter circuit 11, the other end of the inductor L2 is connected to the connector Vo and also connected to the anode of the filter capacitor E6, and the cathode of the filter capacitor E6 is connected to the connector Go for outputting the final dc voltage; the negative electrode of the filter capacitor E6 is also connected with the negative electrode of a filter capacitor E5 in the output voltage conversion and rectification filter circuit 11.

The super-capacitor charging circuit 15 comprises a power chip U4, a diode D20, a filter capacitor E7, an inductor L1, a capacitor C10, a capacitor C11, a capacitor C12, a resistor R30, a resistor R31, a resistor R32 and a resistor R33, wherein an eighth pin VIN of the power chip U4 is an input voltage pin and is connected with the anode of the filter capacitor E5 in the output voltage conversion and rectification filter circuit 11, a seventh pin VC is connected with the anode of the filter capacitor E6 through the capacitor C11, and the capacitor C12 is connected in parallel with two ends of the filter capacitor E6; a fifth pin CS of the power chip U4 is connected with the cathode of the filter capacitor E6 through a resistor R32 and a resistor R33; a fourth pin FB of the power supply chip U4 is connected with the super capacitor discharging circuit 16 through a resistor R30 and a resistor R31, a second pin SW is connected with one end of an inductor L1, the other end of the inductor L1 is connected with the anode of a filter capacitor E7, the cathode of the filter capacitor E7 is connected with the cathode of a filter capacitor E5 on one hand, and is connected with an inductor L1 through a diode D20 on the other hand, a capacitor C10 is connected with two ends of the filter capacitor E7 in parallel, and the anode of the filter capacitor E7 is also connected with the super capacitor discharging circuit (16), so that constant current charging of an external super capacitor is guaranteed.

The super capacitor discharging circuit 16 comprises a thermistor RT1 and a diode D19, wherein the anode of the diode D19 is connected with the anode of a filter capacitor E7 in the super capacitor charging circuit 15, the cathode of the diode D is connected with the anode of a filter capacitor E6 in the output filter circuit 14, one end of the thermistor RT1 is connected with the cathode of the filter capacitor E6 through a resistor R33, the other end of the thermistor RT1 is connected with the cathode connector C-of the super capacitor, and the anode of the diode D19 is also connected with the anode connector C + of the super capacitor and used for supplying power to an external load and limiting discharging current.

The alternating voltage power-off signal circuit 13 comprises a diode D17 and a capacitor C9, wherein the anode of the diode D17 is connected with the sixth pin and the seventh pin of the transformer T1 in the output voltage conversion and rectification filter circuit 11, and the cathode is connected with the power-off signal isolation circuit 17, and is used for acquiring a voltage signal transformed by the transformer T1 and transmitting the voltage signal to the power-off signal isolation circuit 17; one end of the capacitor C9 is connected to the cathode of the diode D17, and the other end is connected to the cathode of the filter capacitor E6 in the output filter circuit 14.

The power-off signal isolation circuit 17 comprises an optical coupler U5 and a resistor R34, wherein one input end of the optical coupler U5 is connected with the cathode of a diode D17 in the alternating-current voltage power-off signal circuit 13 through the resistor R34, the other input end of the optical coupler U5 is connected with the cathode of a filter capacitor E6 in the output filter circuit 14, and two output ends of the optical coupler U5 are connected with a connector COM and a connector POW1 and used for isolating and transmitting a power-supply power-off signal to an external control circuit.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims

1. The utility model provides a high-voltage power line capacitance gets special switching power supply, its characterized in that, including surge voltage clamp circuit (1) of access three-phase four-wire system high-voltage electric network, a current limiting circuit (2) for limiting the line current, three-phase four-wire full wave rectifier circuit (3) of converting four-wire alternating voltage into direct current ripple voltage, an EMI filter circuit (4) for keeping apart high frequency interference signal, power factor correction and energy storage circuit (5), PWM transform switch circuit (7), output voltage conversion and rectification filter circuit (11), output filter circuit (14), super capacitor charging circuit (15), super capacitor discharge circuit (16), wherein:

the power factor correction and energy storage circuit (5) comprises a first filter capacitor E1, a second filter capacitor E2, a third filter capacitor E3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode D9, a second diode D10, a third diode D11, a fourth diode D12, a fifth diode D13 and a sixth diode D14, wherein the cathode of the first filter capacitor E1 is connected with the cathode of the first diode D9, the anode of the first filter capacitor E1 is connected with one of the output ends of the EMI filter circuit (4), and the anode of the first diode D9 is connected with the ground and is also connected with the other output end of the EMI filter circuit (4); the anode of the second filter capacitor E2 is connected to the anode of the third diode D11, the cathode thereof is connected to the cathode of the fourth diode D12, the cathode of the third diode D11 is connected to the anode of the first filter capacitor E1, and the anode of the fourth diode D12 is connected to the anode of the first diode D9; the anode of the third filter capacitor E3 is connected to the anode of the sixth diode D14, the cathode thereof is connected to the anode of the first diode D9, and the cathode of the sixth diode D14 is connected to the anode of the first filter capacitor E1; the anode of the second diode D10 is connected with the cathode of the first filter capacitor E1, and the cathode of the second diode D10 is connected with the anode of the second filter capacitor E2; the anode of the fifth diode D13 is connected with the cathode of the second filter capacitor E2, and the cathode of the fifth diode D13 is connected with the anode of the third filter capacitor E3; the first resistor R1 and the second resistor R2 are connected in series and then connected in parallel to two ends of the first filter capacitor E1, and the third resistor R3 and the fourth resistor R4 are connected in series and then connected in parallel to two ends of the second filter capacitor E2;

2. The special switching power supply for the high-voltage power line capacitance power taking according to claim 1, further comprising a power compensation circuit (6), wherein the power compensation circuit (6) is formed by sequentially connecting a plurality of resistors of the same type in series, one end of the power compensation circuit (6) is connected with the anode of the first filter capacitor E1 in the power factor correction and energy storage circuit (5), and the other end is connected with the source of the MOS transistor Q1 in the PWM conversion switching circuit (7) through a thirteenth resistor R15.

3. The special switching power supply for high-voltage power line capacitive power taking according to claim 1, further comprising a PWM control circuit (10), an overvoltage protection circuit (9), and an output voltage feedback closed-loop control circuit (12), wherein:

4. The special switching power supply for high-voltage power line capacitive powering according to claim 3, further comprising a VCC power supply circuit (8), wherein the VCC power supply circuit (8) is composed of a seventh filter capacitor E4, an eleventh diode D16, and a plurality of resistors connected in series, wherein an anode of the eleventh diode D16 is connected to the first pin of the transformer T1, a cathode of the eleventh diode D16 is connected to the anode of the seventh filter capacitor E4, and a cathode of the seventh filter capacitor E4 is grounded; one end of the plurality of resistors connected in series is connected with the fifth pin of the transformer T1, and the other end of the plurality of resistors is connected with the anode of the seventh filter capacitor E4; the anode of the seventh filter capacitor E4 is also connected to the second pin VCC of the PWM control chip U1.

5. The special switching power supply for capacitive power taking of the high-voltage power line according to claim 1, further comprising an alternating-current voltage power-off signal circuit (13) and a power-off signal isolation circuit (17), wherein:

6. The special switching power supply for the capacitive power taking of the high-voltage power line according to claim 1, wherein the surge voltage clamping circuit (1) is composed of four piezoresistors, one end of each piezoresistor is connected with a three-phase four-wire system high-voltage power grid, and the other end of each piezoresistor is connected with one end of the other three piezoresistors, which is not connected with the high-voltage power grid; the current limiting circuit (2) consists of four current limiting resistors, one ends of the four current limiting resistors are connected with a high-voltage power grid, and the other ends of the four current limiting resistors are connected with the three-phase four-wire full-wave rectifying circuit (3); the three-phase four-wire full-wave rectifying circuit (3) consists of eight high-voltage diodes to form a full-wave rectifying circuit, and a current-limiting resistor is connected between every two high-voltage diodes which are connected in the same direction; the EMI filter circuit (4) is composed of a thirteenth capacitor C1 and a third inductor LB1, two input ends of the third inductor LB1 are connected with two output ends of the three-phase four-wire full-wave rectifying circuit (3), and two output ends of the third inductor LB1 are connected with the power factor correction and energy storage circuit (5), wherein the output end corresponding to the input end of the third inductor LB1 connected with the cathode of the high-voltage diode is connected with the anode of the first filter capacitor E1, and the output end corresponding to the input end connected with the anode of the high-voltage diode is connected with the anode of the first diode D9; the thirteenth capacitor C1 is connected in parallel to the input terminal of the third inductor LB 1.