Wuhan UHV specializes in producing a power frequency withstand voltage test device (also known as series resonance). Below are the test factors that affect the power frequency withstand voltage test.

The main factors affecting the power frequency withstand voltage test are as follows:

1. We need to choose the appropriate capacity of the testing equipment. If the capacity of the testing equipment is insufficient or too large, it will have an impact on the on-site testing.  

2. The influence of altitude on the required test values: As altitude increases, spatial density decreases, and the average free path of electrons in the electric field increases. Electrons can gather greater kinetic energy between two collisions (compared to normal density), making them more prone to ionization and resulting in a decrease in the discharge voltage of the air medium.

3. Prevent overvoltage during the test process: During the power frequency withstand voltage test, if the voltage is not gradually increased from zero, but rather on the primary winding of the test transformer, overvoltage will occur on the test sample due to excitation inrush current; If the power is suddenly cut off during the experiment, for small capacitance samples, overvoltage may occur due to self inductance potential. Both of the above situations may cause accidental breakdown of the test object. Therefore, when conducting the power frequency withstand voltage test, the test operation procedures should be strictly followed.

4. The influence of capacitance rise effect on test values: During the AC power frequency withstand voltage test, the test object is usually a capacitive load, and the high-voltage winding of the test transformer is connected to the capacitance of the test object. In this way, the capacitive current flowing through the capacitive load causes a voltage drop in the impedance of the test transformer winding. The voltage on the secondary side of the test transformer increases significantly, which is significantly greater than the secondary side voltage calculated according to the transformation ratio. This phenomenon is called the "capacitance rise effect". It can be seen that the original transformation ratio is no longer applicable. The rise program is proportional to the short-circuit impedance of the transformer, and the general range of rise is about 4% to 30%. To avoid misjudgment caused by measurement errors, the voltage on the high-voltage side of the test object with a larger test capacitance should be directly measured.

5. The influence of voltage waveform distortion on test results: Due to the input of many nonlinear loads by the power consumption unit, the harmonic circuit components are increased, which makes the problem of voltage waveform distortion in the power grid increasingly serious. In order to protect the correctness of test results, it is necessary to measure its peak value to eliminate measurement errors caused by voltage ripple distortion.