CN113036937B

CN113036937B - Current induction power supply

Info

Publication number: CN113036937B
Application number: CN202110223324.1A
Authority: CN
Inventors: 沈阿大
Original assignee: Hefei Hemei Electronic Technology Co ltd
Current assignee: Hefei Hemei Electronic Technology Co ltd
Priority date: 2021-03-01
Filing date: 2021-03-01
Publication date: 2024-05-10
Anticipated expiration: 2041-03-01
Also published as: CN113036937A

Abstract

The invention discloses a current induction power supply, which comprises: the induction circuit is used for acquiring current through electromagnetic induction; a filter circuit for filtering the current in the circuit to suppress a rising rate of the current in the circuit; the protection circuit is used for discharging and protecting the back-end circuit for the current of the induction circuit; a rectifying circuit for rectifying the alternating current in the circuit into direct current; the bleeder circuit is used for timely releasing the energy stored when the magnetic core of the induction circuit is saturated; the voltage stabilizing circuit is used for outputting a stabilized voltage; the induction circuit, the filter circuit, the protection circuit, the rectifying circuit, the bleeder circuit and the voltage stabilizing circuit are electrically connected in sequence. The energy stored in the magnetic core during saturation can be discharged, and the magnetic core has a primary voltage stabilizing function. The input of the post-stage voltage stabilizing circuit is more stable, and the impact of high voltage generated by transient short circuit faults on the power grid on the voltage stabilizing circuit is avoided. The reliability and stability of the power supply are greatly enhanced.

Description

Current induction power supply

Technical Field

The invention relates to the technical field of power electronics, in particular to a current induction power supply.

Background

CT gets electricity (current induction gets electricity), namely, a CT device arranged on a power line is utilized to obtain electric energy through an electromagnetic induction principle, and power is supplied to equipment.

The power monitoring system is an important component of the whole intelligent power grid, the proportion of the power monitoring system is more than 40%, and at present, the power supply of equipment in the on-line monitoring process of a power transmission line is always a troublesome problem. Photovoltaic electricity taking, wind energy, storage batteries, laser energy supply and the like are adopted in the conventional cases, but the electricity taking modes are extremely easy to be influenced by the external environment, the service life of the device, the installation and use modes and the like. Particularly in winter, the power taking and supplying capacity of the power supply can be greatly reduced in long-time cloudy days and snowy days, and larger manpower and maintenance cost are generated. Therefore, induction power taking (CT power taking) from a power line is a main idea for solving the problem of on-line monitoring of power supply equipment at present.

The condition of the primary bus current at the high-voltage side of the power transmission and transformation system is very complex, and the current is only a few amperes at ordinary times, and the transient current generated by the current surge, short circuit fault and other reasons can reach tens of kiloamperes. A bleeder circuit is added at the front stage or the rear stage of a rectifier bridge of a common CT power supply. The method has no good limitation on transient high current and inrush current of a power grid, and easily generates excessive voltage and current impact on subsequent circuits. Thereby causing power damage.

Disclosure of Invention

The invention aims to provide a current induction power supply which is used for solving the problem that in the prior art, transient large current and inrush current of a power grid are not well limited, and excessive voltage and current impact are easily generated for a subsequent circuit; thereby causing a problem of power damage.

The invention provides a current induction power supply, which comprises: the induction circuit is used for acquiring current through electromagnetic induction; a filter circuit for filtering the current in the circuit to suppress a rising rate of the current in the circuit; the protection circuit is used for discharging and protecting the back-end circuit for the current of the induction circuit; a rectifying circuit for rectifying the alternating current in the circuit into direct current; the bleeder circuit is used for timely releasing the energy stored when the magnetic core of the induction circuit is saturated; the voltage stabilizing circuit is used for outputting a stabilized voltage; the induction circuit, the filter circuit, the protection circuit, the rectifying circuit, the bleeder circuit and the voltage stabilizing circuit are electrically connected in sequence.

In an embodiment of the invention, the induction circuit includes an electromagnetic induction coil and an adjustable resistor VR1; the electromagnetic induction coil and an external high-voltage bus are mutually induced; and two ends of the adjustable resistor VR1 are respectively and electrically connected with the high-voltage output end and the low-voltage output end of the electromagnetic induction coil.

In an embodiment of the invention, the filter circuit includes a first inductor L1, a first safety capacitor CX1 and a second safety capacitor CX2; one end of the first inductor L1 is connected with one end of the first safety capacitor CX1 and the high-voltage output end of the electromagnetic induction coil, and the other end of the first inductor L1 is connected with one end of the second safety capacitor CX2; the other end of the first safety capacitor CX1 and the other end of the second safety capacitor CX2 are connected with the low-voltage output end of the electromagnetic induction coil.

In an embodiment of the present invention, the protection circuit includes a first protection resistor Ra, a second protection resistor Rb, a third safety capacitor CX3, a fifth safety capacitor CX5, a first voltage transformer TV1, and a silicon controlled rectifier SCR; one end of the first protection resistor Ra and one end of the second protection resistor Rb are connected in parallel and then connected with the high-voltage output end of the electromagnetic induction coil, the other end of the first protection resistor Ra and one end of the second protection resistor Rb are connected with the input end of the first voltage transformer TV1, and the other end of the first protection resistor Rb is connected with one end of the third safety capacitor CX 3; the other end of the third safety capacitor CX3 is connected with the low-voltage output end of the electromagnetic induction coil; the output end of the first voltage transformer TV1 is connected with the control end of the silicon controlled rectifier SCR; and two ends of the silicon controlled rectifier SCR and the fifth safety capacitor CX5 are respectively connected with the high-voltage output end and the mortgage output end of the electromagnetic induction coil.

In an embodiment of the invention, the rectifying circuit includes a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4; the anode of the first diode D1 and the cathode of the second diode D2 are respectively connected with the high-voltage output end of the electromagnetic induction coil, and the anode of the third diode D3 and the cathode of the fourth diode D4 are respectively connected with the low-voltage output end of the electromagnetic induction coil; the cathode of the first diode D1 is connected to the cathode of the third diode D3, and the anode of the second diode D2 is connected to the anode of the fourth diode D4.

In an embodiment of the invention, the bleeder circuit includes a first capacitor C0, a fourth inductor L4, a first MOS field effect transistor Q1, a thirty-second resistor R32, a third resistor R3, a 4 th resistor R4, a fifth diode D5, a sixth diode D6, a fourth safety capacitor CX4, a first electrolytic capacitor E1, a second capacitor C1, a third capacitor C2, a second electrolytic capacitor E2, a twenty-first resistor R21, a twenty-second resistor R22, a sixteenth capacitor C15, a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a seventeenth capacitor C16, a third chip U3, a twenty-seventh resistor R27, a twenty-ninth resistor R29, a thirty-fourth resistor R30, an eighteenth capacitor C17, and a nineteenth capacitor C18; one end of the first capacitor C0 is connected with one end of the fourth inductor L4, and the other end of the first capacitor C0 is grounded; the grid electrode of the first MOS field effect transistor Q1 is connected with one end of the thirty-second resistor R32, the drain electrode is connected with the other end of the fourth inductor L4 and the anode of the sixth diode D6, and the source electrode is grounded; the other end of the thirty-second resistor R32 is grounded; the anode of the fifth diode D5 is connected with one end of the fourth inductor L4, and the cathode of the fifth diode D5 is connected with the cathode of the second diode D6; one end of the third resistor R3 and one end of the 4 th resistor R4 are connected in parallel and then connected with the anode of the sixth diode D6, the other end of the third resistor R3 and one end of the fourth safety capacitor CX4 are connected, and the other end of the fourth safety capacitor CX4 is grounded; one end of the first electrolytic capacitor E1, the second capacitor C1, the third capacitor C2 and the second electrolytic capacitor E2 which are connected in parallel is connected with the anode of the sixth diode D6 and the external high voltage, and the other end of the first electrolytic capacitor E1, the second capacitor C2 and the second electrolytic capacitor E2 is grounded; one end of the twenty-first resistor R21 is connected with an external high voltage, the other end of the twenty-second resistor R22 is connected with one end of the twenty-second resistor R22, and the other end of the twenty-second resistor R22 is grounded; one end of the sixteenth capacitor C15 is connected with the-IN pin of the third chip U3, and the other end of the sixteenth capacitor C is grounded; one end of the twenty-third resistor R23 is connected with external high voltage, the other end of the twenty-sixth resistor R26 is connected with one end of the twenty-sixth resistor R26, and the other end of the twenty-sixth resistor R26 is grounded; two ends of the seventeenth capacitor C16 are respectively connected with two ends of the twenty-sixth resistor R26; one end of the twenty-fifth resistor R25 is connected with the other end of the twenty-third resistor R23, and the other end of the twenty-fifth resistor R is connected with the +IN pin of the third chip U3; one end of the twenty-seventh resistor R27 is connected with the +IN pin of the third chip U3, and the other end of the twenty-seventh resistor R is connected with the OUT pin of the third chip U3; one end of the thirty-first resistor R30 is connected with an OUT pin of the third chip U3, and the other end of the thirty-first resistor R is connected with a grid electrode of the first MOS field effect transistor Q1; one end of the eighteenth capacitor C17 and one end of the nineteenth capacitor C18 are connected in parallel and then connected with a +Vs pin of the third chip U3, and the other end of the eighteenth capacitor C17 and the nineteenth capacitor C18 are connected with a-Vs pin of the third chip U3; the-Vs pin of the third chip U3 is grounded; one end of the twenty-ninth resistor R29 is connected with external high voltage, and the other end of the twenty-ninth resistor R29 is connected with a +Vs pin of the third chip U3.

In an embodiment of the invention, the device further comprises a charging control circuit for continuously supplying power to the subsequent circuit through the battery when the high-voltage bus is not provided with current; the charge control circuit includes: eleventh capacitor C10, twelfth capacitor C11, thirteenth capacitor C13, second chip U2, fourth chip U4, fifth chip U5, sixth chip U6, seventh chip U7, eleventh resistor R11, twelfth resistor R12, thirteenth resistor R13, fourteenth resistor R14, fifteenth resistor R15, fourteenth capacitor C13, sixteenth resistor R16, seventeenth resistor R17, eighteenth resistor R18, nineteenth resistor R19, twenty resistor R20, power supply component, fifteenth capacitor C15, fortieth resistor R40, twenty capacitor C19, thirty-first resistor R31, twenty-third capacitor C22, twenty-fourth capacitor C23, twenty-fifth capacitor C24, twenty-sixth capacitor C25, thirty-third resistor R33, thirty-fourth resistor R34, thirty-fifth resistor R35, thirty-sixth resistor R36, thirty-seventh resistor R37, thirty-eighth resistor R38, twenty-seventh capacitor C26, twenty-eighth capacitor C27, twenty-eighth capacitor C28, twenty-first capacitor R1, thirty-ninth capacitor C31, thirty-eighth capacitor C30, thirty-eighth resistor R29, thirty-eighth resistor R30; one end of the eleventh capacitor C10, the twelfth capacitor C11 and the thirteenth capacitor C13 after being connected in parallel are connected with the Vin pin of the second chip U2, and the other end of the eleventh capacitor C11 and the thirteenth capacitor C13 is grounded; two ends of the eleventh resistor R11 are respectively connected with the Vin pin and the Vcc pin of the second chip U2; one end of the twelfth resistor R12 is connected with the Vcc pin of the second chip U2, and the other end of the twelfth resistor R is grounded; one end of the thirteenth resistor R13 is connected to the Sout1 pin of the second chip U2, and the other end thereof is connected to the ground; one end of the fourteenth resistor R14 is connected with the Sout2 pin of the second chip U2, and the other end of the fourteenth resistor R is connected with the ground; one end of the fifteenth resistor R15 is connected with the PG pin of the second chip U2, and the other end of the fifteenth resistor R is grounded; the OUT pin and the Bat pin of the second chip U2 are connected and then connected with the power supply assembly; two ends of the fourteenth capacitor C13 are respectively connected with an OUT pin and a set pin of the second chip U2; one end of the sixteenth resistor R16 is connected with external high voltage, and the other end of the sixteenth resistor R is connected with a TS pin of the second chip U2; the seventeenth resistor R17 and the eighteenth resistor R18 are connected in parallel, one end of the seventeenth resistor R17 is connected with a set pin of the second chip U2 in a terminating mode, and the other end of the seventeenth resistor R18 is grounded; one end of the nineteenth resistor R19 and the twentieth resistor R20 which are connected in parallel is connected with the TS pin of the second chip U2, and the other end of the nineteenth resistor R19 and the twentieth resistor R20 is grounded; the power supply assembly comprises a battery, and two ends of the fifteenth capacitor C15 are respectively connected with an anode and a cathode of the battery; the cathode of the battery is grounded, and the anode of the battery is connected with the IN pin of the fourth chip U4; two ends of the forty resistor R40 are respectively connected with an IN pin and an EN pin of the fourth chip U4; two GND pins of the fourth chip U4 are grounded; one end of the twentieth capacitor C19 is connected with the OUT pin of the fourth chip U4, and the other end of the twentieth capacitor C is grounded; two ends of the thirty-first resistor R31 are respectively connected with a Vdd pin and an EN pin of the fifth chip U5; the NC pin and the GND pin of the fifth chip U5 are connected and then grounded; the OUT pin of the fifth chip U5 is connected with an external high voltage; one end of the twenty-third capacitor C22, the twenty-fourth capacitor C23, the twenty-fifth capacitor C24 and the twenty-sixth capacitor C25 are connected in parallel, and then connected with an OUT pin of the fifth chip U5, and the other end is grounded; one end of the thirty-third resistor R33 is connected with the EN pin of the fourth chip U4, and the other end of the thirty-third resistor R33 is connected with the Vout pin of the sixth chip U6; one end of the thirty-fourth resistor R34 is connected with the Vout pin of the sixth chip U6, and the other end of the thirty-fourth resistor R34 is connected with the +IN pin of the sixth chip U6; one end of the thirty-seventh resistor R37 and one end of the thirty-eighth resistor R38 are connected IN parallel and then are connected with external high voltage, the other end of the thirty-fifth resistor R35 is connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-fifth resistor R35 is connected with a +IN pin of the sixth chip U6; the Vref pin and the-IN pin of the sixth chip U6 are connected; one end of the thirty-sixth resistor R36 and one end of the twenty-ninth capacitor C28 which are connected in parallel are connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-sixth resistor R36 is grounded; one end of the twenty-seventh capacitor C26 is connected to the +vs pin of the sixth chip U6, and the other end is grounded; one end of the twenty-eighth capacitor C27 is connected with the Vref pin of the sixth chip U6, and the other end of the twenty-eighth capacitor C is grounded; one end of the first resistor R1 is connected with external high voltage, the other end of the first resistor R1 is connected with one end of the forty-first resistor R41, and the other end of the forty-first resistor R41 is connected with a-IN pin of the seventh chip U7; the Vref pin and the +IN pin of the seventh chip U7 are connected, the +Vs pin is connected with external high voltage, and the-Vs pin is grounded; one end of the second resistor R2 is connected with an EN pin of the fifth chip U5, and the other end of the second resistor R2 is connected with a Vout pin of the seventh chip U7; one end of the thirty-ninth resistor R39 and the thirty-first capacitor C30 which are connected in parallel are connected with the other end of the first resistor R1; one end of the thirty-second capacitor C29 is connected to the +vs pin of the seventh chip U7, and the other end is grounded; one end of the thirty-second capacitor C31 is connected to the +in pin of the seventh chip U7, and the other end is grounded.

In an embodiment of the invention, the voltage stabilizing circuit includes a fifth capacitor C4, a sixth capacitor C5, a tenth resistor R10, a first chip U1, a third inductor L3, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a seventh capacitor C6, an eighth capacitor C7, a tenth capacitor C9, a third electrolytic capacitor E3, and a seventh diode D7; one end of the tenth resistor R10 is connected with external high voltage, and the other end of the tenth resistor R is connected with a Sleep pin of the first chip U1; the Vin pin and the EN pin of the first chip U1 are connected and then grounded, the AGND pin and the PGND pin are connected and then grounded, the SW pin is connected with one end of the third inductor L3, the VOS pin is connected with the other end of the third inductor L3, and the FB pin and the NC pin are respectively connected with two ends of the eighth resistor R8; one end of the eighth resistor R8 is grounded, the other end of the eighth resistor R8 is connected with one end of the seventh resistor R7, and the other end of the seventh resistor R7 and one end of the ninth resistor R9 are both connected with external high voltage; one end of the tenth capacitor C9 is connected with the other end of the ninth resistor R9, and the other end of the tenth capacitor C9 is grounded; one end of the fifth capacitor C4, the sixth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are connected in parallel and then are connected with external high voltage, and the other end of the fifth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are grounded; and the anode of the seventh diode D7 is connected with external high voltage, and the other end of the seventh diode D is electrically connected with the charging control circuit.

The current induction power supply has the following advantages:

The input end is added with a smoothing inductance and a filter capacitance, and the rear stage of the rectifier bridge is added with a pre-voltage-stabilizing control-bleeder circuit, so that the pre-voltage-stabilizing control-bleeder circuit can bleed off the energy stored in the magnetic core during saturation and has a primary voltage-stabilizing function. The input of the post-stage voltage stabilizing circuit is more stable, and the impact of high voltage generated by transient short-circuit fault heavy current and surge on the power grid on the voltage stabilizing circuit is avoided. The reliability and stability of the power supply are greatly enhanced. The power supply can reliably work when the input line current of the high-voltage power network is changed from a few A to tens of thousands A.

Drawings

The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate the invention and together with the embodiments of the invention, serve to explain the invention. In the drawings:

Fig. 1 is a schematic circuit diagram of a current sensing power supply according to the present invention.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments.

Referring to fig. 1, fig. 1 is a schematic circuit diagram of a current sensing power supply according to the present invention. The invention provides a current induction power supply, which comprises: the induction circuit is used for acquiring current through electromagnetic induction; a filter circuit for filtering the current in the circuit to suppress a rising rate of the current in the circuit; the protection circuit is used for discharging and protecting the back-end circuit for the current of the induction circuit; a rectifying circuit for rectifying the alternating current in the circuit into direct current; the bleeder circuit is used for timely releasing the energy stored when the magnetic core of the induction circuit is saturated; the voltage stabilizing circuit is used for outputting a stabilized voltage; the induction circuit, the filter circuit, the protection circuit, the rectifying circuit, the bleeder circuit and the voltage stabilizing circuit are electrically connected in sequence.

In one embodiment of the present invention, the induction circuit includes an electromagnetic induction coil and an adjustable resistor VR1; the electromagnetic induction coil and an external high-voltage bus are mutually induced; and two ends of the adjustable resistor VR1 are respectively and electrically connected with the high-voltage output end and the low-voltage output end of the electromagnetic induction coil. The ring-shaped structure is adopted to encircle the power transmission and transformation high-voltage bus, and through the electromagnetic induction principle, when current passes through the bus, the current can be induced by the power taking coil for the use of a later-stage circuit. In this embodiment, the electromagnetic induction coil is a CT induction coil, and is composed of an electromagnetic core and a coil. The magnetic core adopts high-performance permalloy. Through electromagnetic induction principle, when current flows through the high-voltage bus, induction energy is obtained inside the CT induction coil and is transmitted to a later-stage circuit for use.

Further, the filter circuit comprises a first inductor L1, a first safety capacitor CX1 and a second safety capacitor CX2; one end of the first inductor L1 is connected with one end of the first safety capacitor CX1 and the high-voltage output end of the electromagnetic induction coil, and the other end of the first inductor L1 is connected with one end of the second safety capacitor CX2; the other end of the first safety capacitor CX1 and the other end of the second safety capacitor CX2 are connected with the low-voltage output end of the electromagnetic induction coil. And a surge current suppression and filtering circuit is formed by adopting proper inductance and capacitance. When the current on the high-voltage bus is smaller, the voltage generated on the subsequent circuit is also lower, and the inhibition effect is also small. The greater the current on the high voltage bus, or the greater the short-circuit fault current, the greater its suppression of the surge current. Meanwhile, the voltage division function is generated, so that abrupt high voltage cannot be generated on the subsequent-stage circuit. And plays a role in protecting a later-stage circuit.

In another embodiment, the protection circuit includes a first protection resistor Ra, a second protection resistor Rb, a third safety capacitor CX3, a fifth safety capacitor CX5, a first voltage transformer TV1, and a silicon controlled rectifier SCR; one end of the first protection resistor Ra and one end of the second protection resistor Rb are connected in parallel and then connected with the high-voltage output end of the electromagnetic induction coil, the other end of the first protection resistor Ra and one end of the second protection resistor Rb are connected with the input end of the first voltage transformer TV1, and the other end of the first protection resistor Rb is connected with one end of the third safety capacitor CX 3; the other end of the third safety capacitor CX3 is connected with the low-voltage output end of the electromagnetic induction coil; the output end of the first voltage transformer TV1 is connected with the control end of the silicon controlled rectifier SCR; and two ends of the silicon controlled rectifier SCR and the fifth safety capacitor CX5 are respectively connected with the high-voltage output end and the mortgage output end of the electromagnetic induction coil. When the post-stage voltage stabilizing circuit cannot work due to faults, if the energy obtained by the CT induction coil cannot be released, an excessive voltage is generated at the output end of the CT coil. This voltage may be detrimental to the subsequent circuitry and operators. The passive-open circuit protection circuit is adopted, a control signal is not needed to be externally added, the CT coil can be discharged, and the safety of a later-stage circuit and operators is protected when the later-stage circuit does not work.

Further, the rectifying circuit includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4; the anode of the first diode D1 and the cathode of the second diode D2 are respectively connected with the high-voltage output end of the electromagnetic induction coil, and the anode of the third diode D3 and the cathode of the fourth diode D4 are respectively connected with the low-voltage output end of the electromagnetic induction coil; the cathode of the first diode D1 is connected to the cathode of the third diode D3, and the anode of the second diode D2 is connected to the anode of the fourth diode D4. The rectifying circuit is capable of rectifying an input alternating current to become a direct current.

Preferably, the bleeder circuit includes a first capacitor C0, a fourth inductor L4, a first MOS field effect transistor Q1, a thirty-second resistor R32, a third resistor R3, a4 th resistor R4, a fifth diode D5, a sixth diode D6, a fourth safety capacitor CX4, a first electrolytic capacitor E1, a second capacitor C1, a third capacitor C2, a second electrolytic capacitor E2, a twenty-first resistor R21, a twenty-second resistor R22, a sixteenth capacitor C15, a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a seventeenth capacitor C16, a third chip U3, a twenty-seventh resistor R27, a twenty-ninth resistor R29, a thirty-first resistor R30, an eighteenth capacitor C17, and a nineteenth capacitor C18; one end of the first capacitor C0 is connected with one end of the fourth inductor L4, and the other end of the first capacitor C0 is grounded; the grid electrode of the first MOS field effect transistor Q1 is connected with one end of the thirty-second resistor R32, the drain electrode is connected with the other end of the fourth inductor L4 and the anode of the sixth diode D6, and the source electrode is grounded; the other end of the thirty-second resistor R32 is grounded; the anode of the fifth diode D5 is connected with one end of the fourth inductor L4, and the cathode of the fifth diode D5 is connected with the cathode of the second diode D6; one end of the third resistor R3 and one end of the 4 th resistor R4 are connected in parallel and then connected with the anode of the sixth diode D6, the other end of the third resistor R3 and one end of the fourth safety capacitor CX4 are connected, and the other end of the fourth safety capacitor CX4 is grounded; one end of the first electrolytic capacitor E1, the second capacitor C1, the third capacitor C2 and the second electrolytic capacitor E2 which are connected in parallel is connected with the anode of the sixth diode D6 and the external high voltage, and the other end of the first electrolytic capacitor E1, the second capacitor C2 and the second electrolytic capacitor E2 is grounded; one end of the twenty-first resistor R21 is connected with an external high voltage, the other end of the twenty-second resistor R22 is connected with one end of the twenty-second resistor R22, and the other end of the twenty-second resistor R22 is grounded; one end of the sixteenth capacitor C15 is connected with the-IN pin of the third chip U3, and the other end of the sixteenth capacitor C is grounded; one end of the twenty-third resistor R23 is connected with external high voltage, the other end of the twenty-sixth resistor R26 is connected with one end of the twenty-sixth resistor R26, and the other end of the twenty-sixth resistor R26 is grounded; two ends of the seventeenth capacitor C16 are respectively connected with two ends of the twenty-sixth resistor R26; one end of the twenty-fifth resistor R25 is connected with the other end of the twenty-third resistor R23, and the other end of the twenty-fifth resistor R is connected with the +IN pin of the third chip U3; one end of the twenty-seventh resistor R27 is connected with the +IN pin of the third chip U3, and the other end of the twenty-seventh resistor R is connected with the OUT pin of the third chip U3; one end of the thirty-first resistor R30 is connected with an OUT pin of the third chip U3, and the other end of the thirty-first resistor R is connected with a grid electrode of the first MOS field effect transistor Q1; one end of the eighteenth capacitor C17 and one end of the nineteenth capacitor C18 are connected in parallel and then connected with a +Vs pin of the third chip U3, and the other end of the eighteenth capacitor C17 and the nineteenth capacitor C18 are connected with a-Vs pin of the third chip U3; the-Vs pin of the third chip U3 is grounded; one end of the twenty-ninth resistor R29 is connected with external high voltage, and the other end of the twenty-ninth resistor R29 is connected with a +Vs pin of the third chip U3. The fourth inductor L4, the fifth diode D5, the sixth diode D6, the third chip U3 and the auxiliary resistor-capacitor thereof of the first MOS field effect transistor Q1 form a bleeder circuit with a pre-voltage stabilizing function. The alternating current obtained by CT electricity taking is subjected to smoothing inductance to inhibit smoothing and rectifier bridge rectification, and the obtained direct current voltage still fluctuates within a certain range. Its peak value is more likely to exceed the voltage limit that can be tolerated by the subsequent stage. In order to ensure that the post-stage circuit works more safely and reliably, the pre-voltage stabilizing circuit can perform primary voltage stabilization within a certain range, meets the requirement of the input voltage range of the post-stage circuit, and ensures that the final voltage stabilizing circuit works reliably. And simultaneously, when larger current appears on the high-voltage bus, the saturation phenomenon can appear when the CT takes the electromagnetic core. If the energy stored during the saturation of the magnetic core cannot be released in time, the magnetic core cannot acquire the energy again to be provided for a later-stage circuit for use when the next induction period arrives, and the later-stage circuit is in a power-off state, so that the stability of the whole detection system is affected. Therefore, the partial circuit also has a discharging function, so that the stored energy after the magnetic core is saturated is released quickly, and the preparation is made for the induction power taking of the next period.

In an embodiment, the device further comprises a charging control circuit for continuously supplying power to the subsequent circuit through the battery when the high-voltage bus is not provided with current; the charge control circuit includes: eleventh capacitor C10, twelfth capacitor C11, thirteenth capacitor C13, second chip U2, fourth chip U4, fifth chip U5, sixth chip U6, seventh chip U7, eleventh resistor R11, twelfth resistor R12, thirteenth resistor R13, fourteenth resistor R14, fifteenth resistor R15, fourteenth capacitor C13, sixteenth resistor R16, seventeenth resistor R17, eighteenth resistor R18, nineteenth resistor R19, twenty resistor R20, power supply component, fifteenth capacitor C15, fortieth resistor R40, twenty capacitor C19, thirty-first resistor R31, twenty-third capacitor C22, twenty-fourth capacitor C23, twenty-fifth capacitor C24, twenty-sixth capacitor C25, thirty-third resistor R33, thirty-fourth resistor R34, thirty-fifth resistor R35, thirty-sixth resistor R36, thirty-seventh resistor R37, thirty-eighth resistor R38, twenty-seventh capacitor C26, twenty-eighth capacitor C27, twenty-eighth capacitor C28, twenty-first capacitor R1, thirty-ninth capacitor C31, thirty-eighth capacitor C30, thirty-eighth resistor R29, thirty-eighth resistor R30; one end of the eleventh capacitor C10, the twelfth capacitor C11 and the thirteenth capacitor C13 after being connected in parallel are connected with the Vin pin of the second chip U2, and the other end of the eleventh capacitor C11 and the thirteenth capacitor C13 is grounded; two ends of the eleventh resistor R11 are respectively connected with the Vin pin and the Vcc pin of the second chip U2; one end of the twelfth resistor R12 is connected with the Vcc pin of the second chip U2, and the other end of the twelfth resistor R is grounded; one end of the thirteenth resistor R13 is connected to the Sout1 pin of the second chip U2, and the other end thereof is connected to the ground; one end of the fourteenth resistor R14 is connected with the Sout2 pin of the second chip U2, and the other end of the fourteenth resistor R is connected with the ground; one end of the fifteenth resistor R15 is connected with the PG pin of the second chip U2, and the other end of the fifteenth resistor R is grounded; the OUT pin and the Bat pin of the second chip U2 are connected and then connected with the power supply assembly; two ends of the fourteenth capacitor C13 are respectively connected with an OUT pin and a set pin of the second chip U2; one end of the sixteenth resistor R16 is connected with external high voltage, and the other end of the sixteenth resistor R is connected with a TS pin of the second chip U2; the seventeenth resistor R17 and the eighteenth resistor R18 are connected in parallel, one end of the seventeenth resistor R17 is connected with a set pin of the second chip U2 in a terminating mode, and the other end of the seventeenth resistor R18 is grounded; one end of the nineteenth resistor R19 and the twentieth resistor R20 which are connected in parallel is connected with the TS pin of the second chip U2, and the other end of the nineteenth resistor R19 and the twentieth resistor R20 is grounded; the power supply assembly comprises a battery, and two ends of the fifteenth capacitor C15 are respectively connected with an anode and a cathode of the battery; the cathode of the battery is grounded, and the anode of the battery is connected with the IN pin of the fourth chip U4; two ends of the forty resistor R40 are respectively connected with an IN pin and an EN pin of the fourth chip U4; two GND pins of the fourth chip U4 are grounded; one end of the twentieth capacitor C19 is connected with the OUT pin of the fourth chip U4, and the other end of the twentieth capacitor C is grounded; two ends of the thirty-first resistor R31 are respectively connected with a Vdd pin and an EN pin of the fifth chip U5; the NC pin and the GND pin of the fifth chip U5 are connected and then grounded; the OUT pin of the fifth chip U5 is connected with an external high voltage; one end of the twenty-third capacitor C22, the twenty-fourth capacitor C23, the twenty-fifth capacitor C24 and the twenty-sixth capacitor C25 are connected in parallel, and then connected with an OUT pin of the fifth chip U5, and the other end is grounded; one end of the thirty-third resistor R33 is connected with the EN pin of the fourth chip U4, and the other end of the thirty-third resistor R33 is connected with the Vout pin of the sixth chip U6; one end of the thirty-fourth resistor R34 is connected with the Vout pin of the sixth chip U6, and the other end of the thirty-fourth resistor R34 is connected with the +IN pin of the sixth chip U6; one end of the thirty-seventh resistor R37 and one end of the thirty-eighth resistor R38 are connected IN parallel and then are connected with external high voltage, the other end of the thirty-fifth resistor R35 is connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-fifth resistor R35 is connected with a +IN pin of the sixth chip U6; the Vref pin and the-IN pin of the sixth chip U6 are connected; one end of the thirty-sixth resistor R36 and one end of the twenty-ninth capacitor C28 which are connected in parallel are connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-sixth resistor R36 is grounded; one end of the twenty-seventh capacitor C26 is connected to the +vs pin of the sixth chip U6, and the other end is grounded; one end of the twenty-eighth capacitor C27 is connected with the Vref pin of the sixth chip U6, and the other end of the twenty-eighth capacitor C is grounded; one end of the first resistor R1 is connected with external high voltage, the other end of the first resistor R1 is connected with one end of the forty-first resistor R41, and the other end of the forty-first resistor R41 is connected with a-IN pin of the seventh chip U7; the Vref pin and the +IN pin of the seventh chip U7 are connected, the +Vs pin is connected with external high voltage, and the-Vs pin is grounded; one end of the second resistor R2 is connected with an EN pin of the fifth chip U5, and the other end of the second resistor R2 is connected with a Vout pin of the seventh chip U7; one end of the thirty-ninth resistor R39 and the thirty-first capacitor C30 which are connected in parallel are connected with the other end of the first resistor R1; one end of the thirty-second capacitor C29 is connected to the +vs pin of the seventh chip U7, and the other end is grounded; one end of the thirty-second capacitor C31 is connected to the +in pin of the seventh chip U7, and the other end is grounded. Under the condition that the high-voltage bus is powered off for a short time, the additional rechargeable battery can continuously provide power for subsequent instruments and equipment for a certain time, so that the instruments and equipment can work normally.

Further, the voltage stabilizing circuit includes a fifth capacitor C4, a sixth capacitor C5, a tenth resistor R10, a first chip U1, a third inductor L3, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a seventh capacitor C6, an eighth capacitor C7, a tenth capacitor C9, a third electrolytic capacitor E3, and a seventh diode D7; one end of the tenth resistor R10 is connected with external high voltage, and the other end of the tenth resistor R is connected with a Sleep pin of the first chip U1; the Vin pin and the EN pin of the first chip U1 are connected and then grounded, the AGND pin and the PGND pin are connected and then grounded, the SW pin is connected with one end of the third inductor L3, the VOS pin is connected with the other end of the third inductor L3, and the FB pin and the NC pin are respectively connected with two ends of the eighth resistor R8; one end of the eighth resistor R8 is grounded, the other end of the eighth resistor R8 is connected with one end of the seventh resistor R7, and the other end of the seventh resistor R7 and one end of the ninth resistor R9 are both connected with external high voltage; one end of the tenth capacitor C9 is connected with the other end of the ninth resistor R9, and the other end of the tenth capacitor C9 is grounded; one end of the fifth capacitor C4, the sixth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are connected in parallel and then are connected with external high voltage, and the other end of the fifth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are grounded; and the anode of the seventh diode D7 is connected with external high voltage, and the other end of the seventh diode D is electrically connected with the charging control circuit. The voltage stabilizing circuit outputs stable and reliable voltage for other instruments and equipment.

The current induction power supply provided by the invention has the advantages that the input end is added with the smoothing inductor and the filter capacitor, the rear stage of the rectifier bridge is added with the pre-voltage stabilizing control-discharging circuit, and the circuit can discharge the energy stored in the magnetic core during saturation and has a primary voltage stabilizing function. The input of the post-stage voltage stabilizing circuit is more stable, and the impact of high voltage generated by transient short-circuit fault heavy current and surge on the power grid on the voltage stabilizing circuit is avoided. The reliability and stability of the power supply are greatly enhanced. The power supply can reliably work when the input line current of the high-voltage power network is changed from a few A to tens of thousands A.

The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.

Claims

1. A current-sensing power supply, comprising:

the induction circuit is used for acquiring current through electromagnetic induction;

A filter circuit for filtering the current in the circuit to suppress a rising rate of the current in the circuit;

the protection circuit is used for discharging and protecting the back-end circuit for the current of the induction circuit;

a rectifying circuit for rectifying the alternating current in the circuit into direct current;

The bleeder circuit is used for timely releasing the energy stored when the magnetic core of the induction circuit is saturated;

the voltage stabilizing circuit is used for outputting a stabilized voltage;

The induction circuit, the filter circuit, the protection circuit, the rectifying circuit, the bleeder circuit and the voltage stabilizing circuit are electrically connected in sequence;

the induction circuit comprises an electromagnetic induction coil and an adjustable resistor VR1; the electromagnetic induction coil and an external high-voltage bus are mutually induced; the two ends of the adjustable resistor VR1 are respectively and electrically connected with the high-voltage output end and the low-voltage output end of the electromagnetic induction coil;

the filter circuit comprises a first inductor L1, a first safety capacitor CX1 and a second safety capacitor CX2;

One end of the first inductor L1 is connected with one end of the first safety capacitor CX1 and the high-voltage output end of the electromagnetic induction coil, and the other end of the first inductor L1 is connected with one end of the second safety capacitor CX 2;

the other end of the first safety capacitor CX1 and the other end of the second safety capacitor CX2 are connected with the low-voltage output end of the electromagnetic induction coil;

The protection circuit comprises a first protection resistor Ra, a second protection resistor Rb, a third safety capacitor CX3, a fifth safety capacitor CX5, a first voltage transformer TV1 and a silicon controlled rectifier SCR;

One end of the first protection resistor Ra and one end of the second protection resistor Rb are connected in parallel and then connected with the high-voltage output end of the electromagnetic induction coil, the other end of the first protection resistor Ra and one end of the second protection resistor Rb are connected with the input end of the first voltage transformer TV1, and the other end of the first protection resistor Rb is connected with one end of the third safety capacitor CX 3; the other end of the third safety capacitor CX3 is connected with the low-voltage output end of the electromagnetic induction coil;

The output end of the first voltage transformer TV1 is connected with the control end of the silicon controlled rectifier SCR; the two ends of the silicon controlled rectifier SCR and the fifth safety capacitor CX5 are respectively connected with the high-voltage output end and the mortgage output end of the electromagnetic induction coil;

the rectifying circuit comprises a first diode D1, a second diode D2, a third diode D3 and a fourth diode D4;

The anode of the first diode D1 and the cathode of the second diode D2 are respectively connected with the high-voltage output end of the electromagnetic induction coil, and the anode of the third diode D3 and the cathode of the fourth diode D4 are respectively connected with the low-voltage output end of the electromagnetic induction coil;

the cathode of the first diode D1 is connected with the cathode of the third diode D3, and the anode of the second diode D2 is connected with the anode of the fourth diode D4;

the bleeder circuit comprises a first capacitor C0, a fourth inductor L4, a first MOS field effect transistor Q1, a thirty-second resistor R32, a third resistor R3, a4 th resistor R4, a fifth diode D5, a sixth diode D6, a fourth safety capacitor CX4, a first electrolytic capacitor E1, a second capacitor C1, a third capacitor C2, a second electrolytic capacitor E2, a twenty-first resistor R21, a twenty-second resistor R22, a sixteenth capacitor C15, a twenty-third resistor R23, a twenty-fifth resistor R25, a twenty-sixth resistor R26, a seventeenth capacitor C16, a third chip U3, a twenty-seventh resistor R27, a twenty-ninth resistor R29, a thirty-eighth resistor R30, an eighteenth capacitor C17 and a nineteenth capacitor C18;

One end of the first capacitor C0 is connected with one end of the fourth inductor L4, and the other end of the first capacitor C0 is grounded; the grid electrode of the first MOS field effect transistor Q1 is connected with one end of the thirty-second resistor R32, the drain electrode is connected with the other end of the fourth inductor L4 and the anode of the sixth diode D6, and the source electrode is grounded; the other end of the thirty-second resistor R32 is grounded; the anode of the fifth diode D5 is connected with one end of the fourth inductor L4, and the cathode of the fifth diode D6 is connected with the cathode of the sixth diode D6; one end of the third resistor R3 and one end of the 4 th resistor R4 are connected in parallel and then connected with the anode of the sixth diode D6, the other end of the third resistor R3 and one end of the fourth safety capacitor CX4 are connected, and the other end of the fourth safety capacitor CX4 is grounded; one end of the first electrolytic capacitor E1, the second capacitor C1, the third capacitor C2 and the second electrolytic capacitor E2 which are connected in parallel is connected with the anode of the sixth diode D6 and the external high voltage, and the other end of the first electrolytic capacitor E1, the second capacitor C2 and the second electrolytic capacitor E2 is grounded;

One end of the twenty-first resistor R21 is connected with an external high voltage, the other end of the twenty-second resistor R22 is connected with one end of the twenty-second resistor R22, and the other end of the twenty-second resistor R22 is grounded; one end of the sixteenth capacitor C15 is connected with the-IN pin of the third chip U3, and the other end of the sixteenth capacitor C is grounded; one end of the twenty-third resistor R23 is connected with external high voltage, the other end of the twenty-sixth resistor R26 is connected with one end of the twenty-sixth resistor R26, and the other end of the twenty-sixth resistor R26 is grounded; two ends of the seventeenth capacitor C16 are respectively connected with two ends of the twenty-sixth resistor R26; one end of the twenty-fifth resistor R25 is connected with the other end of the twenty-third resistor R23, and the other end of the twenty-fifth resistor R is connected with the +IN pin of the third chip U3; one end of the twenty-seventh resistor R27 is connected with the +IN pin of the third chip U3, and the other end of the twenty-seventh resistor R is connected with the OUT pin of the third chip U3; one end of the thirty-first resistor R30 is connected with an OUT pin of the third chip U3, and the other end of the thirty-first resistor R is connected with a grid electrode of the first MOS field effect transistor Q1; one end of the eighteenth capacitor C17 and one end of the nineteenth capacitor C18 are connected in parallel and then connected with a +Vs pin of the third chip U3, and the other end of the eighteenth capacitor C17 and the nineteenth capacitor C18 are connected with a-Vs pin of the third chip U3; the-Vs pin of the third chip U3 is grounded; one end of the twenty-ninth resistor R29 is connected with external high voltage, and the other end of the twenty-ninth resistor R29 is connected with a +Vs pin of the third chip U3;

The charging control circuit is used for continuously supplying power to the subsequent circuit through the battery when the high-voltage bus is currentless;

The charge control circuit includes:

Eleventh capacitor C10, twelfth capacitor C11, thirteenth capacitor C12, second chip U2, fourth chip U4, fifth chip U5, sixth chip U6, seventh chip U7, eleventh resistor R11, twelfth resistor R12, thirteenth resistor R13, fourteenth resistor R14, fifteenth resistor R15, fourteenth capacitor C13, sixteenth resistor R16, seventeenth resistor R17, eighteenth resistor R18, nineteenth resistor R19, twenty resistor R20, power supply component, fifteenth capacitor C15, fortieth resistor R40, twenty capacitor C19, thirty-first resistor R31, twenty-third capacitor C22, twenty-fourth capacitor C23, twenty-fifth capacitor C24, twenty-sixth capacitor C25, thirty-third resistor R33, thirty-fourth resistor R34, thirty-fifth resistor R35, thirty-sixth resistor R36, thirty-seventh resistor R37, thirty-eighth resistor R38, twenty-seventh capacitor C26, twenty-eighth capacitor C27, twenty-eighth capacitor C28, twenty-first capacitor R1, thirty-ninth capacitor C31, thirty-eighth capacitor C30, thirty-eighth resistor R29, thirty-eighth resistor R30;

One end of the eleventh capacitor C10, the twelfth capacitor C11 and the thirteenth capacitor C12 after being connected in parallel are connected with the Vin pin of the second chip U2, and the other end of the eleventh capacitor C11 and the thirteenth capacitor C12 is grounded; two ends of the eleventh resistor R11 are respectively connected with the Vin pin and the Vcc pin of the second chip U2; one end of the twelfth resistor R12 is connected with the Vcc pin of the second chip U2, and the other end of the twelfth resistor R is grounded; one end of the thirteenth resistor R13 is connected to the Sout1 pin of the second chip U2, and the other end thereof is connected to the ground; one end of the fourteenth resistor R14 is connected with the Sout2 pin of the second chip U2, and the other end of the fourteenth resistor R is connected with the ground; one end of the fifteenth resistor R15 is connected with the PG pin of the second chip U2, and the other end of the fifteenth resistor R is grounded; the OUT pin and the Bat pin of the second chip U2 are connected and then connected with the power supply assembly;

Two ends of the fourteenth capacitor C13 are respectively connected with an OUT pin and a set pin of the second chip U2; one end of the sixteenth resistor R16 is connected with external high voltage, and the other end of the sixteenth resistor R is connected with a TS pin of the second chip U2; the seventeenth resistor R17 and the eighteenth resistor R18 are connected in parallel, one end of the seventeenth resistor R17 is connected with a set pin of the second chip U2 in a terminating mode, and the other end of the seventeenth resistor R18 is grounded; one end of the nineteenth resistor R19 and the twentieth resistor R20 which are connected in parallel is connected with the TS pin of the second chip U2, and the other end of the nineteenth resistor R19 and the twentieth resistor R20 is grounded;

The power supply assembly comprises a battery, and two ends of the fifteenth capacitor C15 are respectively connected with an anode and a cathode of the battery; the cathode of the battery is grounded, and the anode of the battery is connected with the IN pin of the fourth chip U4; two ends of the forty resistor R40 are respectively connected with an IN pin and an EN pin of the fourth chip U4; two GND pins of the fourth chip U4 are grounded; one end of the twentieth capacitor C19 is connected with the OUT pin of the fourth chip U4, and the other end of the twentieth capacitor C is grounded;

Two ends of the thirty-first resistor R31 are respectively connected with a Vdd pin and an EN pin of the fifth chip U5; the NC pin and the GND pin of the fifth chip U5 are connected and then grounded; the OUT pin of the fifth chip U5 is connected with an external high voltage; one end of the twenty-third capacitor C22, the twenty-fourth capacitor C23, the twenty-fifth capacitor C24 and the twenty-sixth capacitor C25 are connected in parallel, and then connected with an OUT pin of the fifth chip U5, and the other end is grounded;

One end of the thirty-third resistor R33 is connected with the EN pin of the fourth chip U4, and the other end of the thirty-third resistor R33 is connected with the Vout pin of the sixth chip U6; one end of the thirty-fourth resistor R34 is connected with the Vout pin of the sixth chip U6, and the other end of the thirty-fourth resistor R34 is connected with the +IN pin of the sixth chip U6; one end of the thirty-seventh resistor R37 and one end of the thirty-eighth resistor R38 are connected IN parallel and then connected with external high voltage, the other end of the thirty-fifth resistor R35 is connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-fifth resistor R35 is connected with a +IN pin of the sixth chip U6; the Vref pin and the-IN pin of the sixth chip U6 are connected; one end of the thirty-sixth resistor R36 and one end of the twenty-ninth capacitor C28 which are connected in parallel are connected with one end of the thirty-fifth resistor R35, and the other end of the thirty-sixth resistor R36 is grounded; one end of the twenty-seventh capacitor C26 is connected to the +vs pin of the sixth chip U6, and the other end is grounded; one end of the twenty-eighth capacitor C27 is connected with the Vref pin of the sixth chip U6, and the other end of the twenty-eighth capacitor C is grounded;

One end of the first resistor R1 is connected with external high voltage, the other end of the first resistor R1 is connected with one end of the forty-first resistor R41, and the other end of the forty-first resistor R41 is connected with a-IN pin of the seventh chip U7; the Vref pin and the +IN pin of the seventh chip U7 are connected, the +Vs pin is connected with external high voltage, and the-Vs pin is grounded; one end of the second resistor R2 is connected with an EN pin of the fifth chip U5, and the other end of the second resistor R2 is connected with a Vout pin of the seventh chip U7; one end of the thirty-ninth resistor R39 and the thirty-first capacitor C30 which are connected in parallel are connected with the other end of the first resistor R1; one end of the thirty-second capacitor C29 is connected to the +vs pin of the seventh chip U7, and the other end is grounded; one end of the thirty-second capacitor C31 is connected to the +in pin of the seventh chip U7, and the other end is grounded.

2. The current-sensing power supply according to claim 1, wherein the voltage stabilizing circuit comprises a fifth capacitor C4, a sixth capacitor C5, a tenth resistor R10, a first chip U1, a third inductor L3, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a seventh capacitor C6, an eighth capacitor C7, a tenth capacitor C9, a third electrolytic capacitor E3, and a seventh diode D7;

One end of the tenth resistor R10 is connected with external high voltage, and the other end of the tenth resistor R is connected with a Sleep pin of the first chip U1; the Vin pin and the EN pin of the first chip U1 are connected and then grounded, the AGND pin and the PGND pin are connected and then grounded, the SW pin is connected with one end of the third inductor L3, the VOS pin is connected with the other end of the third inductor L3, and the FB pin and the NC pin are respectively connected with two ends of the eighth resistor R8; one end of the eighth resistor R8 is grounded, the other end of the eighth resistor R8 is connected with one end of the seventh resistor R7, and the other end of the seventh resistor R7 and one end of the ninth resistor R9 are both connected with external high voltage; one end of the tenth capacitor C9 is connected with the other end of the ninth resistor R9, and the other end of the tenth capacitor C9 is grounded; one end of the fifth capacitor C4, the sixth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are connected in parallel and then are connected with external high voltage, and the other end of the fifth capacitor C5, the seventh capacitor C6, the eighth capacitor C7 and the third electrolytic capacitor E3 are grounded; and the anode of the seventh diode D7 is connected with external high voltage, and the other end of the seventh diode D is electrically connected with the charging control circuit.