By hvhipot 
Voltage withstand test is the main basis for testing the ability of electrical appliances, electrical equipment, electrical circuits, and electrical safety equipment to withstand overvoltage and determining the normal insulation level of various electrical equipment in the power system. When should I choose DC withstand voltage or AC withstand voltage? Next, we will explain the difference between DC withstand voltage and AC withstand voltage using ZGF DC high voltage generator and series resonance test device.
When using a DC high-voltage generator for DC withstand voltage testing, it can effectively detect overall defects such as insulation moisture and dirt, and can also discover local insulation defects through the relationship curve between current and leakage current. Due to the voltage division based on insulation resistance under DC voltage, it is more effective in detecting end insulation defects than AC voltage. At the same time, due to the fact that insulation does not produce dielectric loss under DC voltage, the destructive effect of DC withstand voltage on insulation is minimal. In addition, due to the fact that DC withstand voltage only requires a small leakage current supply, the required testing equipment has a small capacity and is easy to carry.
When using a series resonance test device for AC withstand voltage testing: at 2.5 times or more the voltage of the tested equipment, from the perspective of thermal breakdown of dielectric loss, local free defects and weak points of insulation aging can be effectively discovered. Due to the fact that the voltage is mainly divided by capacitance under AC voltage, it can effectively expose the insulation defects of the equipment. Moreover, since the test current is a capacitive current, a large capacity test equipment is required.
In summary, both DC withstand voltage test and power frequency AC withstand voltage test can effectively detect insulation defects, but each has its own characteristics. When conducting withstand voltage test, the two methods cannot replace each other, and if necessary, they should be carried out simultaneously and complement each other.
HV Hipot Electric Co., Ltd. specializes in the production of series resonance (also known as series resonance withstand voltage device) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.