Technology Class

Measurement of capacitance and dielectric loss of circuit-breaker capacitor is a very important task to ensure safe and stable running of circuit-breaker. However, due to serious electric interference to on-site measurement, dielectric losses of more and more 500kV circuit-breaker capacitor exceeded the limit at 10kV test voltage according to the CSG trial standard. To address the above-mentioned problems, the paper proposes that methods of using different frequency power source and boosting test voltage be utilized to measure the capacitance and dielectric loss. Based on the above measuring methods, several common test schemes are put forward and application ranges are also analyzed followed by capacitance and dielectric loss measurement for some 500kV circuit-breaker capacitor at substation. Test results indicate that the dielectric loss of capacitor reduces as the voltage rises; the change in test voltage frequency can effectively shield the interference from on-site electric field.

Power quality refers to the quality of the AC power supplied to the user through the public power grid. Generally speaking, it refers to the quality of the power in the power grid lines. Power quality problems are mainly caused by the terminal load side. For example, the impact reactive load will cause the grid voltage to generate Violent fluctuations reduce the quality of power supply. When the power quality of the power grid is disturbed or polluted and cannot meet the relevant national standards, it is necessary to improve the power quality of the power grid in a targeted manner. To understand the actual situation of the power quality of the power grid, it is necessary to have the corresponding equipment power quality analyzer ( Also known as three-phase power quality analyzer) to test and analyze it.

What are the methods of AC withstand voltage test based on series parallel resonance principle? What are the conditions for voltage resonance? What are the conditions for current resonance? What are the methods of series resonance withstand voltage test of transformer? What are the precautions during the series voltage withstand test of the transformer? What are the possible reasons for unqualified insulation of power equipment during voltage withstand test?

What are the methods of AC withstand voltage test based on series parallel resonance principle? What are the conditions for voltage resonance? What are the conditions for current resonance? What are the methods of series resonance withstand voltage test of transformer? What are the precautions during the series voltage withstand test of the transformer? What are the possible reasons for unqualified insulation of power equipment during voltage withstand test?