CN201569675U - Local discharge testing power supply device for ultra-high-voltage transformer - Google Patents

Abstract

The utility model provides a local discharge testing power supply device for an ultra-high-voltage transformer, which comprises a motor, an intermediate-frequency generator, a control protector A, a power supply wire incoming port, a generator wire outgoing port, a low-voltage compensation reactor, an intermediate transformer, a compensation reactor and a sample. The motor, the intermediate-frequency generator and the control protector A are integrated and arranged in a container cabinet made of metal. The utility model can provide a power supply system with small background interference and simple and reliable structure for field voltage sensing and local discharge testing of the ultra-high-voltage transformer, and ensure the local discharge testing power supply system of the transformer which can satisfy the testing requirements for the sample of the ultra-high-voltage transformer.

Description

A partial discharge test power supply device for UHV transformers

technical field

The utility model belongs to the technical field of high voltage and insulation, in particular to a partial discharge test power supply device for an ultra-high voltage transformer.

Background technique

During the long-term operation of the transformer, partial discharge may occur in some weak parts of its internal insulation under high field strength, resulting in insulation degradation. Under the long-term action of severe partial discharge, it may even cause breakdown, resulting in damage to the transformer . Especially for UHV transformers, in order to check whether their insulation performance is intact, long-term induced voltage and partial discharge tests must be carried out after on-site installation to assess their insulation performance. How to use a simple and reliable test power system in the field test to pressurize the UHV transformer test product according to the test research, and at the same time effectively suppress and avoid the interference of the test power system itself, is the interference of the test power system itself in line with the partial discharge test. The discharge background requirement is a problem that needs to be solved. There are following shortcoming in the test power supply system of prior art:

1. The capacity is small, and it is generally tested for transformers of 500kV and below, and it is not suitable for large-capacity transformers.

2. The background interference level of the existing test power supply system is relatively high, which cannot meet the experimental requirements of the 1000kV transformer.

Utility model content

In order to overcome the defects of the prior art, the purpose of this utility model is to provide a transformer for field induced voltage and partial discharge tests of UHV transformers with little background interference, simple and reliable, and capable of meeting the test requirements for UHV transformer samples. Partial discharge test power supply unit.

To this end, a partial discharge test power supply device for UHV transformers, including a motor, an intermediate frequency generator, a control protector A, a power inlet, a generator outlet, a low-voltage compensation reactor, an intermediate transformer, a high-voltage compensation The reactor and the test product are characterized in that: the motor, the intermediate frequency generator, and the control protector A are integrated in a container made of metal; The electric motor supplies power, and the operation of the electric motor drives the intermediate frequency generator to generate intermediate frequency current. The intermediate frequency current is connected to the intermediate transformer for raising the output voltage to the test voltage through the outlet of the generator. A low-voltage compensating reactor is connected in parallel between the transformers to compensate the inductive capacity; after boosted by the intermediate transformer, the voltage is finally applied to the test product for testing, and a high-voltage compensating reactor is connected in parallel between the intermediate transformer and the test product to compensate the inductive capacity; The power inlet and the intermediate frequency generator outlet are respectively arranged on both sides of the upper end of the container container, and the power inlet and the intermediate frequency generator outlet are spatially separated inside the container.

Wherein, the test power supply system has a remote control box, which is drawn from the control protector A and arranged outside the container container. The remote control box includes a control button, an emergency stop button, a liquid crystal display, an input and output interface and an input equipment.

Wherein, the control protector A includes a programmable logic controller, a power acquisition module, a local/remote control converter, a voltage regulator, a contactor, an intermediate relay, an exciter, and a circuit breaker arranged in a shielded cabinet. A control panel with an emergency operation button is provided on the cabinet.

Wherein, the remote control box and the programmable logic controller in the control protector A perform data transmission and communication through cables, optical cables or wireless signals.

Wherein, the test sample is an ultra-high voltage transformer.

Wherein, the low-voltage compensating reactor is a dry-type or oil-immersed low-voltage compensating reactor whose voltage level matches that of the intermediate frequency generator.

Wherein, the high-voltage compensating reactor adopts an oil-immersed insulating cylinder structure, and its insulation voltage level matches the high-voltage side of the intermediate transformer.

The beneficial effects of the utility model are:

1. Integrate the medium frequency motor-generator set and control protector in a standard container, shield the electromagnetic interference of the power supply and control system, reduce radiation to the external space, and avoid the impact on partial discharge detection. At the same time, it is easy to move and transport ;

2. The medium-frequency motor-generator set used is determined according to the power loss of the 1000kV UHV transformer under frequency multiplication, and can provide sufficient active power;

3. Centrally place all control and protection devices in a shielded cabinet and fix them on the bottom plate of the container to reduce the electromagnetic interference of the secondary control and protection system;

4. The 50Hz power inlet and the intermediate frequency (100-200Hz) generator outlet are separately arranged on both sides of the upper end of the container, and the two lines are also strictly separated in space inside the header to avoid coupling interference;

5. The control method combining local and remote control is adopted, and a switch is provided for switching. The local control panel is set on the control, which can monitor the working status of the motor and generator voltage, current, etc., and start, excite, and lift Pressure, emergency stop and other operations; with a remote control box, the system can be remotely controlled and monitored. The local and remote control methods can be used as backup for each other to improve the reliability of the system;

6. The remote control box adopts PLC technology for monitoring and control, uses optical fiber or cable to connect and communicate with the control protector, or uses wireless communication to connect and communicate with the control protector. For the field test, the optical fiber connection communication method can electrically isolate the remote control box and the main system, but because the optical fiber material is relatively brittle, it is easy to be damaged under low temperature or external force, which affects the test; the low-voltage cable is relatively soft and has high reliability, but It is easy to introduce system overvoltage into the remote control box, thereby damaging the remote control box; the wireless communication method saves the connection with the main system, but it may affect the communication reliability due to field interference or various uncertain factors, thereby interrupting the operation process, adversely affecting the test.

Description of drawings

Fig. 1 is a schematic diagram of the module structure of a partial discharge test power supply device for UHV transformers according to the present invention;

Among them, 1-motor, 2-intermediate frequency generator, 3-control cabinet, 4-power inlet (50Hz), 5-generator outlet (200Hz), 6-protection cabinet, 7-remote control box, 8 -Low-voltage compensating reactor, 9-intermediate transformer, 10-high-voltage compensating reactor, 11-test product (UHV transformer).

Detailed ways

The following is a preferred embodiment of the utility model, and the test power supply device of the utility model will be described in further detail below in conjunction with the accompanying drawings.

As shown in Figure 1, the test power supply device of the present utility model integrates the motor 1, the intermediate frequency generator 2, the control protector A, the power inlet 4 and the generator outlet 5 in a container made of metal, and the The 380V/50Hz AC power supply is introduced from the power inlet 4 to supply power for the control protector A and the motor 1 respectively; the motor 1 runs to drive the intermediate frequency generator 2 to generate intermediate frequency power, the current is generally 690-1000 volts, 100 -200Hz; the current from the intermediate frequency generator 2 is connected to the intermediate transformer 9 through the outlet 5 of the generator, and the function of the intermediate transformer 9 is to increase the output voltage to the test voltage (about 200kV); A low-voltage compensating reactor 8 is connected in parallel with the intermediate transformer 9 to compensate the inductive capacity; after the intermediate transformer 9 is boosted, the voltage is finally applied to the test product 11 (using a UHV transformer) for testing; between the intermediate transformer 9 and the test product 11 is connected in parallel with a high voltage compensating reactor 10 to compensate the inductive capacity. The 50Hz power inlet and the 200Hz intermediate frequency generator outlet are respectively arranged at both ends of the container, and the power inlet and the intermediate frequency generator outlet are also separated in space inside the container to avoid two kinds of wires cross set.

The control protector A includes a programmable logic controller, a power acquisition module, a local/remote control converter, a voltage regulator, a contactor, an intermediate relay, an exciter and a circuit breaker; wherein the programmable logic controller (abbreviated as PLC) , the power collection module, the local/remote control converter, the voltage regulator, the contactor, the intermediate relay and the exciter are arranged in the control cabinet 3, and a control panel is also arranged on the control cabinet 3, and an emergency operation button is arranged on the panel; The circuit breaker is arranged in the protection cabinet 6, which includes a motor circuit breaker and a generator outlet circuit breaker, which can cut off the test circuit in time when the motor or generator overvoltage, overcurrent and other faults occur.

The remote control box 7 is drawn from the control protector A, and the remote control box 7 is provided with controls for controlling the opening and closing of the exciter in the protection cabinet 3, the opening and closing of the circuit breaker at the outlet of the generator, and the lifting and lowering of the entire test power supply device. Buttons, emergency stop buttons, input and output interfaces and input devices; at the same time, the remote control box is also provided with a liquid crystal display, which communicates with the PLC in the control cabinet 3 using cables, optical cables or wireless signals.

Example 1

Determine the capacity of the motor 1 and the intermediate frequency generator 2 according to the power supply capacity required by the UHV transformer sample 11 in the partial discharge test. For example, the capacity of the test sample 11 is a single-phase autotransformer with a capacity of 1000MVA, and the motor 1 needs to be selected from 300kW to For a capacity of 1000kW, the medium frequency generator 2 needs to choose a capacity of 800kVA-2500kVA, and the output voltage of the medium frequency generator 2 is 690V-1000V. The control cabinet 3 is equipped with a PLC, a power acquisition module, a local/remote control converter, a voltage regulator, a contactor, an intermediate relay and an exciter, etc., which can control the start and stop of the motor 1, and the excitation circuit of the intermediate frequency generator. Opening and closing, step-up and step-down of intermediate frequency generators, etc.; there are circuit breakers in the protection cabinet 6, which include motor circuit breakers and generator outlet circuit breakers, which can prevent overvoltage and overcurrent faults of motors and generators. When it occurs, cut off the test circuit in time through the emergency operation button on the control panel of the control cabinet 3, so as to prevent the failure from causing harm to people or equipment. The low-voltage compensation reactor can be dry or oil-immersed, and the voltage level is matched with the intermediate frequency generator 2, and the voltage is 690V ~ 1000V. The voltage of the intermediate transformer 9 can step up and transform the voltage of 690V-1000V to the voltage required for the test of about 200kV, so as to meet the requirements of the test product for the test voltage. The insulation voltage level of the high-voltage compensating reactor 10 is matched with the high-voltage side of the intermediate transformer, which is also about 200kV. The remote control box 7 includes a control button for controlling the opening and closing of the exciter, the opening and closing of the generator outlet circuit breaker, and the whole test power supply system's step-down and down-voltage, and an emergency stop button. Communication can display the operating status of the motor, generator, and excitation circuit in real time, as well as parameters such as motor voltage and current, generator voltage and current, generator output active power, generator output voltage, and current phase angle.

The invention has been described above in the context of specific embodiments, but those skilled in the art will also appreciate the many possibilities for variants and alternative embodiments, for example by combining and/or changing features of individual embodiments. Therefore, it should be understood that these modifications and alternative embodiments are to be considered as included in the present invention, the scope of which is limited only by the appended patent claims and their equivalents.

Claims (7)

1. partial discharge test supply unit that is used for extra-high voltage transformer, comprise motor (1), intermediate frequency generator (2), control protector A, electric power incoming line mouth (4), generator outlet mouth (5), low-voltage compensation reactor (8), intermediate transformer (9), high pressure compensation reactor (10) and test product (11), it is characterized in that: described motor (1), intermediate frequency generator (2), control protector A be integrated to be arranged in the container counter that metal prepares; Described electric power incoming line mouth (4) is introduced AC power and is respectively control protector A and motor (1) is powered, described motor (1) running drives intermediate frequency generator (2) operation and sends electric current of intermediate frequency, this electric current of intermediate frequency is linked into the intermediate transformer (9) that is used for output voltage is elevated to trial voltage through generator outlet mouth (5), is parallel with low-voltage compensation reactor (8) and compensates perceptual capacity between intermediate frequency generator (2) and intermediate transformer (9); After intermediate transformer (9) boosted, voltage finally was applied on the test product (11) and tests, and is parallel with high pressure compensation reactor (10) and compensates perceptual capacity between intermediate transformer (9) and test product (11); Described electric power incoming line mouth (4) and intermediate frequency generator line outlet (5) are divided into the both sides, upper end of container counter, and in container counter inside electric power incoming line and intermediate frequency generator outlet are spatially separated.

2. partial discharge test supply unit as claimed in claim 1; it is characterized in that: this experiment power supply system has Long-distance Control case (7); it is drawn from described control protector A and is arranged at outside the container counter, and described Long-distance Control case (7) comprises control knob, emergency stop push button, LCDs, IO interface and input equipment.

3. partial discharge test supply unit as claimed in claim 2; it is characterized in that: described control protector A comprises programmable logic controller (PLC), electric quantity acquisition module, this locality/Long-distance Control converter, pressure regulator, contactor, auxiliary reclay, magnetizing exciter and the isolating switch that is arranged in the shielding rack, is provided with the control panel of emergency operation button on the described rack.

4. partial discharge test supply unit as claimed in claim 3 is characterized in that: described Long-distance Control case (7) carries out data transmission with programmable logic controller (PLC) among the control protector A by cable, optical cable or wireless signal and communicates by letter.

5. as the arbitrary described partial discharge test supply unit of claim 1-4, it is characterized in that: described test product (11) is selected extra-high voltage transformer for use.

6. as the arbitrary described partial discharge test supply unit of claim 1-4, it is characterized in that: described low-voltage compensation reactor (8) adopts the low-voltage compensation reactor of dry type or oil immersed type, and its electric pressure matches with intermediate frequency generator (2).

7. as the arbitrary described partial discharge test supply unit of claim 1-4, it is characterized in that: described high pressure compensation reactor (10) adopts oil immersion insulated barrel-type structure, and its insulation voltage grade matches with the high-pressure side of intermediate transformer (6).