Wuhan UHV specializes in producingseries resonance (also known as series resonance withstand voltage test device). Next, we will share with you what to pay attention to for the series resonance withstand voltage test device?

Attention to Series Resonance (GIS) Test:

1. During the experiment, the high-voltage source should be connected to the test, and the high-voltage lead should use a dedicated non corona lead. Non test connections should be grounded to the GIS casing;

2. The test must ensure that the SF6 gas in each chamber is at the rated pressure, and the gas content is within the qualified range after 4 hours of inflation. The GIS must be in an operational state and confirmed to be correct before the test can be conducted;

3. Before the test pressurization, ensure that the voltage transformers inside the GIS are removed (if approved by the GIS manufacturer, the voltage transformers can be pressurized together, but the test resonance frequency must be greater than 100Hz), the CT is short circuited twice, and the lightning arrester connection should be disconnected;

4. The test voltage is added to the output sleeve, with the sleeve core connected to the high voltage source and the sleeve metal flange connected to the system's dedicated ground wire;

5. During the experiment, dedicated grounding wires must be used between the components of the testing system and between the testing system and the GIS casing. It is strictly prohibited to use on-site grounding bars to replace the grounding wire connection between the testing system and the GIS casing;

6. Note that a single point connection is used between the experimental system and the on-site power grid, and the grounding point must be located on the connection between the voltage divider and the test sample;

Principle and precautions of transformer external test

The external test is a basic test to test the main insulation of the transformer, with a test frequency of not less than 80% of the rated frequency;

Attention to transformer external test:

1. The test winding and non test winding are both short circuited, and the non test winding is short circuited and grounded. In principle, the test sample should not have potential floating;

2. During the experiment, the connection between the variable frequency resonance system and the tested transformer casing is made using the dedicated grounding wire provided by our company;

Principle and precautions of transformer induction withstand voltage test:

The transformer induction withstand voltage test is a basic test that simultaneously checks the main insulation and longitudinal insulation of the transformer The test voltage is generally twice the rated voltage. To avoid iron core saturation, the test frequency should be more than twice the rated frequency. The test frequency is generally specified between 100-400Hz, and experience has shown that a test frequency of 150-200Hz is more suitable;

Attention to transformer induction withstand voltage test:

1. The power supply voltage is applied from the low-voltage winding, the neutral point of the high-voltage winding is not grounded, and the non test phase winding is short circuited to ground;

2. If the transformer has medium voltage winding and balanced winding, be careful not to suspend the potential of these windings;

3. The experimental compensation capacitor is located on the low voltage side, and the voltage divider is located on the high voltage side;

4. During the experiment, the dedicated grounding wire provided by our company is used to connect the test system to the tested transformer;

Generator power frequency withstand voltage test and precautions:

According to the regulations of national and local power departments, generators should undergo AC withstand voltage tests during manufacturing, installation, maintenance, operation, and preventive testing. The waveform and frequency of the test voltage should be consistent with the waveform and frequency of the operating voltage The test voltage is generally 0.75 (2Un+3000) or 1.5Un, and the frequency is the power frequency During the experiment, it is generally sufficient to meet the AC withstand voltage requirements of the generator by equipping it with appropriate compensation capacitors;

Attention to power frequency durability voltage test of generator:

1. By adjusting the compensation capacitor, the resonant frequency is controlled around 50Hz;

2. During the experiment, the series resonance is connected to the tested generator using the dedicated grounding wire provided by our company