CN215817671U

CN215817671U - Energy acquisition circuit applied to high-voltage primary equipment

Info

Publication number: CN215817671U
Application number: CN202121872940.1U
Authority: CN
Inventors: 周旭东
Original assignee: Sichuan Lanxun Baoer Electronic Technology Co Ltd
Current assignee: Sichuan Lanxun Baoer Electronic Technology Co Ltd
Priority date: 2021-08-11
Filing date: 2021-08-11
Publication date: 2022-02-11
Anticipated expiration: 2031-08-11

Abstract

The utility model discloses an energy acquisition circuit applied to high-voltage primary equipment, which is used for converting an alternating current source into low-voltage milliampere-level energy and comprises a current transformer T1, a bridge rectifier D2 and an energy storage capacitor C2, wherein the primary side of the current transformer T1 is connected in series into a leakage current grounding loop of the high-voltage primary equipment, two ends of the secondary side of the current transformer T1 are respectively connected with two alternating current input ends of a bridge rectifier D2, two direct current output ends of the bridge rectifier D2 are respectively connected with two ends of the energy storage capacitor C2, and direct current voltage is output to charge and store energy for the energy storage capacitor C2, so that the low-voltage milliampere-level energy is obtained. The utility model does not need to lay a power cable separately to provide working energy of the high-voltage primary equipment monitoring device.

Description

Energy acquisition circuit applied to high-voltage primary equipment

Technical Field

The utility model relates to the technical field of high-voltage primary equipment, in particular to an energy acquisition circuit applied to the high-voltage primary equipment.

Background

The traditional lightning arrester is monitored by a mechanical discharge counter, the leakage current of the lightning arrester is indicated on site by a mechanical pointer ammeter, the accumulated times of the discharge event of the lightning arrester are displayed on site by the mechanical counter, and workers need to periodically copy and analyze data. At present, a portable tester for measuring the leakage current of the lightning arrester on line exists at home and abroad, but still workers are required to carry the tester to carry out test work and manual data analysis periodically on site. At present, an on-line monitoring device for replacing a mechanical discharge counter at home and abroad has the functions of on-line monitoring of leakage current of an arrester and remote transmission of discharge events and data of the arrester, but the device is large in size and needs to lay independent power supply cables and communication cables, so that a large number of cables need to be ditched and laid on site in engineering implementation, the engineering implementation is difficult to maintain in a large later period, and the problem that an old transformer substation has high implementation safety risk is solved.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems in the prior art, the utility model aims to provide an energy acquisition circuit applied to high-voltage primary equipment, and the utility model does not need to lay a power cable separately to provide working energy of a monitoring device of the high-voltage primary equipment.

In order to achieve the purpose, the utility model adopts the technical scheme that: the utility model provides an energy acquisition circuit for be applied to high-voltage primary equipment for convert alternating current source to low-voltage milliampere level energy, including current transformer T1, bridge rectifier D2 and energy storage capacitor C2, the primary side series connection of current transformer T1 is in the leakage current ground circuit of high-voltage primary equipment, the both ends of the secondary side of current transformer T1 respectively with two AC input end of bridge rectifier D2 are connected, two DC output of bridge rectifier D2 respectively with the both ends of energy storage capacitor C2 are connected, and output DC voltage is to energy storage capacitor C2 charges, thereby obtains low-voltage milliampere level energy.

As a further improvement of the present invention, the energy acquisition circuit further includes a protection circuit, the protection circuit includes a zinc oxide resistor RV1, a wire-wound resistor R1 and a voltage-type trigger diode D1, the zinc oxide resistor RV1 is connected in series in a leakage current ground circuit of the high-voltage primary device, one end of the zinc oxide resistor RV1 is connected to one of the ac input terminals of the bridge rectifier D2 through the wire-wound resistor R1, the other end of the zinc oxide resistor RV1 is connected to the other ac input terminal of the bridge rectifier D2, and the voltage-type trigger diode D1 is connected in parallel between the two ac input terminals of the bridge rectifier D5.

As a further improvement of the present invention, the energy acquisition circuit further includes a voltage comparator U1 and a DC/DC converter U2, the energy storage capacitor C2 is connected to the DC/DC converter U2, and the voltage comparator U1 controls the enable terminal of the DC/DC converter U2 to turn on the power supply for adjustment according to the voltage of the energy storage capacitor C2 and outputs a low-voltage milliamp-level energy source with a stable supply voltage.

As a further improvement of the present invention, the energy harvesting circuit further includes a decoupling filter capacitor C1 disposed between the two dc output terminals of the bridge rectifier D2.

As a further development of the utility model, the high-voltage primary equipment is a lightning arrester or a capacitive equipment.

The utility model has the beneficial effects that:

the leakage current of high-voltage primary equipment in an electric power transformation facility is about hundreds of microamperes to several milliamperes, the leakage current has the characteristic of a constant current source, and an energy acquisition circuit directly utilizes the leakage current of a lightning arrester as an energy source to adjust, process and store the leakage current to provide working energy for the device, so that the situation that a power supply cable is not needed to be laid independently to provide the working energy for the device is achieved.

Drawings

Fig. 1 is a schematic circuit diagram according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Examples

As shown in fig. 1, an energy obtaining circuit applied to a high-voltage primary device is configured to convert an ac current source into a low-voltage milliampere-level energy, and includes a current transformer T1, a bridge rectifier D2, and an energy storage capacitor C2, where a primary side of the current transformer T1 is connected in series to a leakage current ground loop of the high-voltage primary device, two ends of a secondary side of the current transformer T1 are respectively connected to two ac input ends of the bridge rectifier D2, two dc output ends of the bridge rectifier D2 are respectively connected to two ends of the energy storage capacitor C2, and output a dc voltage to charge and store energy in the energy storage capacitor C2, so as to obtain the low-voltage milliampere-level energy.

In this embodiment, the energy obtaining circuit further includes a protection circuit, the protection circuit includes a zinc oxide resistor RV1, a wire-wound resistor R1 and a voltage-type trigger diode D1, the zinc oxide resistor RV1 is connected in series in a leakage current ground loop of the high-voltage primary device, one end of the zinc oxide resistor RV1 is connected to one of the ac input terminals of the bridge rectifier D2 through the wire-wound resistor R1, the other end of the zinc oxide resistor RV1 is connected to the other ac input terminal of the bridge rectifier D2, and the voltage-type trigger diode D1 is connected in parallel between the two ac input terminals of the bridge rectifier D5.

In this embodiment, the energy obtaining circuit further includes a voltage comparator U1 and a DC/DC converter U2, the energy storage capacitor C2 is connected to the DC/DC converter U2, and the voltage comparator U1 controls an enable terminal of the DC/DC converter U2 to turn on a power supply to adjust and output a low-voltage milliamp-level energy source of a stable supply voltage according to the voltage of the energy storage capacitor C2.

In this embodiment, the energy harvesting circuit further includes a decoupling filter capacitor C1 disposed between the two dc output terminals of the bridge rectifier D2.

In this embodiment, the high voltage primary device is a lightning arrester or a capacitive device.

The principle of the present embodiment is further explained below by taking the lightning arrester as an example:

as shown in fig. 1, the arrester leakage current having the constant current source characteristic flows into the circuit from the 1 port and flows out of the circuit from the 2 port.

The zinc oxide resistance sheet RV1 provides a circuit protection function during lightning arrester discharge, the leakage current of the lightning arrester in a high-impedance state in a normal state does not flow through RV1, and the conduction current of the zinc oxide resistance sheet RV1 flows through RV1 during lightning arrester discharge so as to protect subsequent circuits.

The winding resistor R1 has the characteristics of resistance and inductance, the lightning arrester leakage current generates a small terminal voltage through the winding resistor R1 in a normal state, the circuit operation is not influenced, the current is prevented from increasing due to the inductance characteristic of the winding resistor when the lightning arrester discharges, and meanwhile, a higher terminal voltage is generated due to the resistance characteristic of the winding resistor to further protect a subsequent circuit.

The voltage type trigger diode D1 is in a high impedance cutoff state in a normal state, and when the lightning arrester discharges, the voltage energy possibly remained after the lightning arrester is protected by the winding resistor leads the voltage type trigger diode D1 to be conducted to release energy to protect a subsequent circuit.

The primary side of the current transformer T1 is connected in series to the leakage current loop of the lightning arrester, the high-voltage tiny leakage current of the lightning arrester is amplified by a certain multiple, and then the low-voltage high-current energy is output from the secondary side, and the design current amplification factor of the current transformer T1 is determined according to the secondary turn ratio of the current transformer. The leakage current of the lightning arrester is an alternating current constant current source, the alternating current constant current source is changed into a direct current constant current source by the bridge rectifier D2, a farad capacitor or a lithium ion capacitor is used as an energy storage capacitor C2, and the current energy output by the current transformer T1 through secondary measurement is used for charging and storing energy for the energy storage capacitor C2 so as to obtain working energy required by the device to work, for example, the working energy is used for supplying power for a circuit module of a monitoring device of high-voltage primary equipment. The decoupling filter capacitor C1 is used for decoupling filtering and purifying ripple interference.

The voltage comparator U1 discriminates the voltage of the energy storage capacitor C2, when the voltage of the energy storage capacitor C2 reaches a certain threshold value, the voltage comparator U1 controls the EN enabling end of the DC/DC converter U2 to start a power supply to regulate output, and the output is more stable through the DC/DC converter U2.

The above-mentioned embodiments only express the specific embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims

1. The energy obtaining circuit applied to the high-voltage primary equipment is characterized by being used for converting an alternating current source into low-voltage milliampere-level energy and comprising a current transformer T1, a bridge rectifier D2 and an energy storage capacitor C2, wherein the primary side of the current transformer T1 is connected into a leakage current grounding loop of the high-voltage primary equipment in series, two ends of the secondary side of the current transformer T1 are respectively connected with two alternating current input ends of a bridge rectifier D2, two direct current output ends of the bridge rectifier D2 are respectively connected with two ends of the energy storage capacitor C2, and direct current voltage is output to charge and store energy for the energy storage capacitor C2, so that the low-voltage milliampere-level energy is obtained.

2. The energy source obtaining circuit applied to the high-voltage primary equipment, according to claim 1, is characterized in that the energy source obtaining circuit further comprises a protection circuit, the protection circuit comprises a zinc oxide resistor RV1, a wire-wound resistor R1 and a voltage-type trigger diode D1, the zinc oxide resistor RV1 is connected in series in a leakage current ground loop of the high-voltage primary equipment, one end of the zinc oxide resistor RV1 is connected with one of the ac input ends of the bridge rectifier D2 through the wire-wound resistor R1, the other end of the zinc oxide resistor RV1 is connected with the other ac input end of the bridge rectifier D2, and the voltage-type trigger diode D1 is connected in parallel between the two ac input ends of the bridge rectifier D5.

3. The energy source obtaining circuit applied to the high-voltage primary equipment, according to claim 1, is characterized in that the energy source obtaining circuit further comprises a voltage comparator U1 and a DC/DC converter U2, the energy storage capacitor C2 is connected with the DC/DC converter U2, and the voltage comparator U1 controls an enabling end of the DC/DC converter U2 to start power supply adjustment and output low-voltage milliampere-level energy of stable supply voltage according to the voltage of the energy storage capacitor C2.

4. The energy harvesting circuit for high voltage primary equipment according to claim 1, further comprising a decoupling filter capacitor C1 disposed between the two dc outputs of said bridge rectifier D2.

5. The energy harvesting circuit for application to a high voltage primary device according to any of claims 1 to 4, wherein the high voltage primary device is a lightning arrester or a capacitive device.