Excitation transformer is an important component of the power plant transformer group equipment. Its reliable operation is an important factor to ensure the stable safety of the unit. In recent years, due to the failu...Excitation transformer is an important component of the power plant transformer group equipment. Its reliable operation is an important factor to ensure the stable safety of the unit. In recent years, due to the failure of excitation transformer, some power plants have not stop, which has a great impact on the safety of equipment and power supply stability. Combined with the several failures of excitation transformer in a power generation enterprise in recent years, this paper sorts out the problems of excitation transformer in power plant caused by failure one by one, analyzes the causes in depth, and puts forward countermeasures.展开更多
During on-site withstand voltage tests of gas-insulated switchgears(GIS),once a breakdown occurs,it is hard to locate the breakdown position due to the intricate branch structures and minimal breakdown energy.The exis...During on-site withstand voltage tests of gas-insulated switchgears(GIS),once a breakdown occurs,it is hard to locate the breakdown position due to the intricate branch structures and minimal breakdown energy.The existing methods may require the placement of a large number of sensors with unsatisfactory accuracy,which adversely affects the process of inspecting and repairing,as well as the subsequent tests.To address this issue,this paper introduces a novel GIS breakdown location method.This method is predicated on the natural frequency of the transient voltage caused by the breakdown.The relationship between the breakdown position and the natural frequency is first derived,which is referred to as the location equation.Then,the natural frequency characteristics are discussed from both mathematical and energy perspectives.Based on these characteristics,the location method is proposed that utilises the location equation and the frequencies at two measurement points.The results of the laboratory experiments demonstrate the accuracy of the method and certain advantages over the ultrasonic method.Further,the effectiveness of the method in GIS and gas-insulated transmission lines(GIL)with complex structures and high voltage levels is also confirmed by simu-lation cases and field experimental data.展开更多
文摘Excitation transformer is an important component of the power plant transformer group equipment. Its reliable operation is an important factor to ensure the stable safety of the unit. In recent years, due to the failure of excitation transformer, some power plants have not stop, which has a great impact on the safety of equipment and power supply stability. Combined with the several failures of excitation transformer in a power generation enterprise in recent years, this paper sorts out the problems of excitation transformer in power plant caused by failure one by one, analyzes the causes in depth, and puts forward countermeasures.
基金National Key R&D Program of China,Grant/Award Numbers:2022YFB2403700,2022YFB2403705。
文摘During on-site withstand voltage tests of gas-insulated switchgears(GIS),once a breakdown occurs,it is hard to locate the breakdown position due to the intricate branch structures and minimal breakdown energy.The existing methods may require the placement of a large number of sensors with unsatisfactory accuracy,which adversely affects the process of inspecting and repairing,as well as the subsequent tests.To address this issue,this paper introduces a novel GIS breakdown location method.This method is predicated on the natural frequency of the transient voltage caused by the breakdown.The relationship between the breakdown position and the natural frequency is first derived,which is referred to as the location equation.Then,the natural frequency characteristics are discussed from both mathematical and energy perspectives.Based on these characteristics,the location method is proposed that utilises the location equation and the frequencies at two measurement points.The results of the laboratory experiments demonstrate the accuracy of the method and certain advantages over the ultrasonic method.Further,the effectiveness of the method in GIS and gas-insulated transmission lines(GIL)with complex structures and high voltage levels is also confirmed by simu-lation cases and field experimental data.
