CN220855073U

CN220855073U - Ultra-low frequency 0.1Hz pressure-resistant device

Info

Publication number: CN220855073U
Application number: CN202322411427.8U
Authority: CN
Inventors: 李汉明; 沈凡; 叶忠新
Original assignee: Wuhan Musen Electric Co ltd
Current assignee: Wuhan Musen Electric Co ltd
Priority date: 2023-09-06
Filing date: 2023-09-06
Publication date: 2024-04-26
Anticipated expiration: 2033-09-06

Abstract

The utility model discloses an ultralow frequency 0.1Hz voltage withstand device, which comprises a rectifying circuit, an inverter circuit, a transformer, a voltage doubling rectifying circuit and an inverter output circuit, wherein the rectifying circuit is connected with the transformer; the input end of the rectifying circuit inputs 50Hz alternating current, the output end of the rectifying circuit is connected with the inverter circuit, the inverter circuit is connected with the transformer, the transformer is connected with the voltage doubling rectifying circuit, and the voltage doubling rectifying circuit is electrically connected with the inverter output circuit; the voltage doubling rectifying circuit adopts a two-stage voltage doubling rectifying circuit. The inversion output circuit adopts IGCT series connection, after the IGCT fails, the inversion output circuit forms a short circuit by itself, and the redundancy design is adopted in the IGCT series connection. Effects and advantages: 1. the original heavy electromagnetic transformer is changed into an electronic type, the weight is reduced by half, and the electronic type electromagnetic transformer is adopted without oil immersion for heat dissipation, so that the weight is further reduced, and meanwhile, the stability is higher. 2. Withstand voltage can also be measured simultaneously. 3. The lowest frequency can be adjusted to 0.01Hz, and the carrying capacity is stronger.

Description

Ultra-low frequency 0.1Hz pressure-resistant device

Technical Field

The utility model relates to the field of withstand voltage tests, in particular to an ultralow-frequency 0.1Hz withstand voltage device.

Background

The existing pressure-resistant device has the defects that:

1. large and heavy. At present, the domestic 80kV ultra-low frequency adopts a split design of an operation box and a booster, and has large volume; the booster is of electromagnetic oil-immersed type and is heavy.

2. Because of the split design, the wiring is relatively complex.

3. The dielectric loss cannot be measured simultaneously.

4. The lowest frequency can only be adjusted to 0.02Hz, and the carrying capacity is limited.

5. Only 3 gears are adjustable, namely 0.1Hz, 0.05Hz and 0.02Hz, and the application range is limited.

Disclosure of utility model

In order to overcome the defects in the prior art, the utility model provides an ultralow-frequency 0.1Hz voltage withstanding device.

The technical scheme of the utility model is as follows:

An ultralow-frequency 0.1Hz voltage withstand device comprises a rectifying circuit, an inverter circuit, a transformer, a voltage doubling rectifying circuit and an inverter output circuit;

The input end of the rectifying circuit is input with 50Hz alternating current, the output end of the rectifying circuit is connected with the inverter circuit, the inverter circuit is connected with the transformer, the transformer is connected with the voltage doubling rectifying circuit, and the voltage doubling rectifying circuit is electrically connected with the inverter output circuit;

The method comprises the steps of rectifying and inverting the 50Hz alternating current for the first time through a rectifying circuit and an inverting circuit to realize frequency conversion, converting the 50Hz alternating current into 1kHz alternating current so as to reduce the pulsating rate of voltage doubling rectifying output, regulating the voltage of the 1kHz alternating current through a transformer, outputting the regulated voltage to the voltage doubling rectifying circuit, and obtaining the required experimental voltage after the output of the voltage doubling rectifying circuit passes through an inverting output circuit formed by an IGCT (integrated gate commutated thyristor).

The voltage doubling rectifying circuit adopts a two-stage voltage doubling rectifying circuit, so that a transformer with lower voltage can be utilized to obtain higher direct current output voltage.

The inversion output circuit adopts IGCT series connection, and the IGCT forms a short circuit after failure, and the redundancy design is adopted in the IGCT series connection, so that the reliability of the equipment is enhanced.

The control circuit is connected with the IGCT, so that a reliable control signal can be generated to be supplied to the gate electrode of the IGCT to control the on or off of the IGCT, and for a square wave voltage source of 0.1Hz, the control circuit can only generate a small signal of 0.1Hz, so that the control circuit adopts a 0.1Hz oscillator. Thus, control circuits of different precision and different costs can be obtained very simply with analog or digital circuits.

The device also comprises a protection circuit, namely, each serially connected IGCT is connected with an RD-C overvoltage absorbing circuit in parallel, and the RD-C overvoltage absorbing circuit is formed by connecting a resistor and a diode in parallel and then connecting the resistor and the diode in series.

The utility model has the technical effects and advantages that:

1. The original heavy electromagnetic transformer is changed into an electronic type, the weight is reduced by half, and the electronic type electromagnetic transformer is adopted without oil immersion for heat dissipation, so that the weight is further reduced, and meanwhile, the stability is higher.

2. Withstand voltage can also be measured simultaneously.

3. The lowest frequency can be adjusted to 0.01Hz, and the carrying capacity is stronger.

4. 10 Gears can be adjusted from 0.01Hz to 0.1Hz, and the application range is wider.

Drawings

FIG. 1 is a circuit diagram of the present utility model;

FIG. 2 is a schematic diagram of the principles of the present utility model;

Fig. 3 is a detailed diagram of the inverter circuit;

FIG. 4 is a control circuit;

Fig. 5 is an overvoltage absorption circuit.

Detailed Description

The following description of the technical solutions in the embodiments of the present utility model will be clear and complete, and it is obvious that the described embodiments are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

IGCT: INTEGRATED GATE Commutated Thyristors, referred to simply as an integrated gate commutated thyristor.

GU: gate unit

Example 1

The ultralow-frequency 0.1Hz voltage withstand device shown in the figure 1 comprises a rectifying circuit, an inverter circuit, a transformer, a voltage doubling rectifying circuit and an inverter output circuit;

As shown in FIG. 3, when IGCT is connected in series, a device redundancy technology is adopted, and an N+1 connection mode is adopted, namely, when the withstand voltage allowance of the device is considered, one IGCT is connected in series, so that even if the IGCT in a circuit fails, the rest devices can still work normally, at the moment, the light emitting diode is controlled to emit light by utilizing different conduction voltage drops when the IGCT works normally and fails, so that the device is found out and replaced in time, and the reliability of the equipment is greatly improved.

Example two

As shown in fig. 4, the control circuit is connected with the IGCT, so that a reliable control signal can be generated to be supplied to the gate electrode of the IGCT to control the IGCT to turn on or off the circuit, and for a square wave voltage source of 0.1Hz, the control circuit can only generate a small signal of 0.1Hz, therefore, the control circuit with different precision and different cost can be obtained very simply by using an analog circuit or a digital circuit. The 0.1Hz oscillator is adjustable from 0.01Hz to 0.1Hz in 10 gears.

Embodiment III

As shown in FIG. 5, the device also comprises a protection circuit, namely, each series IGCT is connected with an RD-C overvoltage absorbing circuit in parallel, and the RD-C overvoltage absorbing circuit is formed by connecting a resistor and a diode in parallel and then connecting the resistor and the diode in series. The IGCT adopting the redundancy design has extremely high reliability, can bear certain overvoltage, can further reduce the storage time of the IGCT to hundreds of ns after being added with an overvoltage absorption network, and is generally only required to be connected with an RD-C overvoltage absorption circuit shown in figure 5 in parallel on each IGCT connected in series. In addition, since in the cable test, if the insulation of the cable is almost completely broken, it corresponds to a load short circuit, and a great short circuit current flows through the main circuit at this time, it is necessary to add a current limiting reactor as shown in fig. 4 to the circuit to suppress peak current at the time of both arms through or load short circuit.

Example IV

Electromagnetic compatibility design

In the whole design, the strong current system (main circuit) and the weak current system (control circuit) are in the same environment, the strong current system serving as a disturbance source is very easy to generate interference to the control circuit, and in severe cases, the control circuit cannot work normally, so that measures are necessary to avoid or reduce the interference suffered by the weak current system. The main measures adopted are as follows:

1) The connection between the control circuit and the driving circuit adopts a shielding wire, the mesh connection is as short as possible, and the shielding layer adopts double-end grounding to shield electric field and magnetic field interference;

2) Shielding the entire control circuit portion from external circuitry;

3) Different grounding modes are adopted according to specific conditions so as to reduce grounding impedance as much as possible and prevent the ground wire from interfering a control circuit;

4) The main connection line of the control circuit also adopts a shielding line, and the wiring is as short as possible so as to prevent mutual interference between the control circuits.

In addition, because the IGCT is integrated with the gate drive circuit, the incoming line inductance of the drive circuit is greatly reduced, the design is simplified, and a designer does not need to consider the design of the drive part excessively.

The foregoing description of the preferred embodiments of the utility model is not intended to limit the utility model to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and principles of the utility model are intended to be included within the scope of the utility model.

Claims

1. An ultralow-frequency 0.1Hz pressure resistant device is characterized in that: the power supply comprises a rectifying circuit, an inverter circuit, a transformer, a voltage doubling rectifying circuit and an inverter output circuit;

The method comprises the steps of rectifying and inverting 50Hz alternating current for the first time through a rectifying circuit and an inverting circuit to realize frequency conversion, converting the 50Hz alternating current into 1kHz alternating current to reduce the pulse rate of voltage doubling rectifying output, regulating the voltage of the 1kHz alternating current through a transformer, outputting the regulated voltage to the voltage doubling rectifying circuit, and obtaining required experimental voltage after the output of the voltage doubling rectifying circuit passes through an inverting output circuit formed by an IGCT (integrated gate-commutating transistor);

2. The ultralow frequency voltage withstand device of 0.1Hz according to claim 1, characterized in that: the inversion output circuit adopts IGCT series connection, and the IGCT forms a short circuit after failure, and the redundancy design is adopted in the IGCT series connection, so that the reliability of the equipment is enhanced.

3. The ultralow frequency voltage withstand device of 0.1Hz according to claim 1, characterized in that: the control circuit is connected with the IGCT, so that a reliable control signal can be generated to be supplied to the gate electrode of the IGCT to control the on or off of the IGCT, and for a square wave voltage source of 0.1Hz, the control circuit can only generate a small signal of 0.1Hz, so that the control circuit adopts a 0.1Hz oscillator.

4. The ultralow frequency voltage withstand device of 0.1Hz according to claim 1, characterized in that: the device also comprises a protection circuit, namely, each serially connected IGCT is connected with an RD-C overvoltage absorbing circuit in parallel, and the RD-C overvoltage absorbing circuit is formed by connecting a resistor and a diode in parallel and then connecting the resistor and the diode in series.