I、Product introduction：

HZGTU gas-filled non-partial discharge combined electrical test device is suitable for high-voltage, large-capacity GIS, GIL power equipment insulation withstand voltage test, partial discharge test and accuracy test of GIS transformers. It is a necessary device for GIS substations, GIS, GIL power equipment manufacturers, basin insulators, and insulation structural parts manufacturers to conduct preventive tests and factory tests.

Adding a high-voltage casing interface to the equipment can lead to high-voltage, which can perform various high-voltage tests on traditional high-voltage equipment. II.Basic performance of test equipment：

1.Technical index

Voltage level:：100kV、200kV、250kV、300kV、500kV、800kV、1000kV。

Capacity：50-2000kVA

High-voltage generation methods: high-voltage transformer step-up and series resonance (power frequency, variable frequency), all step-up methods are one-stage step-up without cascade step-up.

Input voltage (primary voltage)：0.35-10kV

Partial discharge of equipment: 1-3pc under rated voltage (normal environment)

Temperature rise: the temperature rise is not more than 65k (50Hz) after running at rated current for 60 minutes

2.Technical parameters of test system components

GTU high voltage non-partial discharge test transformer

The GTU high-voltage non-partial discharge test transformer is the key to the test system. It is placed in a specially designed SF6 insulating container. The high-voltage side is separated from other circuits by high-voltage disc insulators. All low-voltage terminals are placed in the junction box.

The low voltage side of the transformer is wound with excitation winding and measurement winding (measurement winding is only used for system testing). For large-capacity (500kVA and above) transformer compensation, there is an independent compensation winding to better play the test of low voltage and load. Flexibility to improve the efficiency of compensation.

The transformer tank is equipped with a gas/vacuum quick connector, a pressure monitoring gauge, an over-pressure release valve, and temperature and pressure sensors for remote monitoring of the operation console.

Note: The rated capacity of the transformer refers to the maximum output of the transformer itself. The installation of other components such as coupling capacitors, capacitive voltage dividers, pipes and disc insulators will reduce the power provided to the test product.

l ZST voltage regulator

The voltage regulator adopts an air-insulated column voltage regulator, which can obtain a smooth voltage output. This component is installed in the same rack as the power isolation transformer and the compensation reactor to facilitate transportation. The input and output ends of the voltage regulator are equipped with air circuit breakers to isolate the system power supply, and the drive motor allows slow and fast voltage regulation speeds. The zero start interlock enables the boost operation to ensure a gradual boost from zero pressure.

Parameters of the voltage regulator：

l lGLB power isolation transformer

The function of the power isolation transformer is mainly to reduce the interference from the main power line to ensure that the background of the partial discharge measurement is below 1Pc.

The capacity is matched with the voltage regulator.

l lHigh pressure measurement

The measurement signal comes from a built-in high voltage divider installed in the system pipeline, and a peak voltmeter can display the peak value, peak value/√2 and effective value of the high voltage voltage.

Measurement accuracy: ±1% of measured value (10%-100% of rated voltage)

Measurement ratio: 10000:1

Rated voltage: match the highest voltage of the system

Rated capacity: 50pf

Partial discharge capacity under rated voltage: ≤1.0pc

l lCoupling capacitor

The coupling capacitor is installed in a specially designed SF6 insulated tank, and the high-voltage electrode is connected to the high-voltage end of the main system through a disc insulator. Since the capacitor is installed in a fully enclosed metal tank, it will not be affected by any other stray capacitances and ensure the high sensitivity of partial discharge measurement. The low-voltage electrode of the coupling capacitor is directly led to the terminal base of the tank through the shielded wire and connected to the measuring impedance.

Rated voltage: match the highest voltage of the system

Rated capacity: 100-200pf

Partial discharge capacity under rated voltage: ≤1.0pc

l BCL Compensation reactor

The compensating reactor is used to compensate the capacitive current of the tested product. The reactor is composed of two coils. The taps of the coils can form a combination of multiple compensation powers. The combination can be manually switched or remotely operated on the operating console.

Compensation reactor technical parameters (some models)

l GTU operation control system

The operation control system provides safe and convenient computer operation for AC high voltage test.

The main function:

Operating

n nHigh-voltage test system diagram is displayed on the large screen for convenient and intuitive operation

n nMain circuit breaker on/off operation

n nContactor on/off operation (high voltage start/stop)

n nAutomatic zero start

n nPreset boost speed (up to 3 speeds can be set)

n nPreset the required high voltage value

n nPreset withstand voltage time (automatically reduce the pressure and cut off the high pressure after the withstand voltage time is over)

n nCompensation reactor on/off

n nHigh voltage isolating switch on/off of test interface

Measuring

n One input current and voltage display

n Display of transformer input current and voltage

n High voltage display

n Withstand voltage test time display

n The pressure display of each SF6 gas chamber of the test system

n Display of transformer SF6 gas chamber temperature

Protection

n Preset over-voltage protection value

n Preset over-current protection value

n Air chamber pressure/temperature automatic protection

n Lock other operations when boosting

l Universal adjustment docking platform

This platform is specially designed for GIS switch test system, it can be very convenient to connect with GIS system flange.

Adjustable range

Vertical adjustment         ±200mm

Horizontal adjustment（X）    ±100mm

Horizontal adjustment（Y）    ±100mm

Angle adjustment         ±5゜

l l Equipment factory test

l After the equipment is assembled, the following tests should be carried out

l l1.1Un high voltage withstand voltage test time 1 minute

l lPartial discharge test to verify that the partial discharge of the entire system of the equipment should be ≤3Pc

l lShort circuit impedance measurement      10%≤

l lMeasurement of partial pressure ratio      ±1%

l l Low-voltage electrical insulation test      3kV for 1 minute

l lTemperature rise test (optional)     1 hour temperature rise of rated current ≤50K

2. Working environment altitude        

Altitude: no restriction on high pressure part

Relative air humidity: no restriction on high pressure part

Ambient temperature: -10゜C---40゜C

With good grounding: ≤0.5Ω

Power supply voltage: The waveform is a sine wave, and the waveform distortion is ≤3%