摘要
As voltage measuring devices are widely used in the high voltage power system with a primary-secondary-fusion structure,electronic voltage transformers are directly connected to the primary conductor and would face much more serious electromagnetic environments than general secondary equipment.As a result,they would still experience failures even when general protection measures are adopted to suppress overvoltages'amplitudes.To address this issue,an innovative method is proposed after analyses are conducted on the resonance between a transformer and an overvoltage.Within this method,an air-cored coil is installed in a transformer to artificially shift its natural frequency and to dodge the high-frequency dominant component of a transient overvoltage,avoiding the aforementioned resonance and suppressing the secondary overvoltage.In addition,simulations and laboratory tests are conducted to prove this method's validity.
基金
National Natural Science Foundation of China,Grant/Award Number:U1866201。
