The main purpose of the electrical power system is to transport and distribute energy generated by the central power plants in a safe and reliable manner to the customer premises. Most of the electrical equipment is e...The main purpose of the electrical power system is to transport and distribute energy generated by the central power plants in a safe and reliable manner to the customer premises. Most of the electrical equipment is exposed within the open which suggests they can be vulnerable to lightning strikes, road dwindling, windstorms, and a few engineering activities with the potential of causing different degrees of damage to the electrical equipment. One of the ways to guard the equipment is to deploy switching devices. However, the operations of most of these switching devices produce oscillatory transient in the electrical transmission and distribution systems which result in voltage, current, and frequency fluctuations in the load. This paper investigates the effect of switching devices on power quality and proposes a positive sequence voltage power transient suppression technique that can spontaneously improve the distorted voltage at the instant of capacitor switching using the capacitor line model as a case study. MATLAB/Simulink software was utilized for the analysis on an electrical network model with bus voltages of 69 kV/12.47 kV and 480 V. The results showed that, during switching operations, the positive sequence voltage power detector block produces ripple-free accurate results.展开更多
Results of calculation the recovery voltages conditioned by capacitive currents switching-off by high voltage vacuum and auto-compression （SF6） circuit-breakers are presented in the article. The purpose of research ...Results of calculation the recovery voltages conditioned by capacitive currents switching-off by high voltage vacuum and auto-compression （SF6） circuit-breakers are presented in the article. The purpose of research was evaluating the maximum values of recovery voltages and also studying the dependence of recovery voltages on some influencing factors, especially on type of circuit-breaker presented in numerical models with its dielectric strength restoration law, chopping current and operation time. The research was carried out with using computer simulation.展开更多
针对40.5 k V真空断路器投切电容器组时重击穿概率高这一亟待解决的技术难题,利用串联断口技术实现电容器组电流开合,提出了40.5 k V双断口真空断路器的设计方案并进行了深入研究,以满足电力系统的要求。建立了由高频涌流振荡回路和工...针对40.5 k V真空断路器投切电容器组时重击穿概率高这一亟待解决的技术难题,利用串联断口技术实现电容器组电流开合,提出了40.5 k V双断口真空断路器的设计方案并进行了深入研究,以满足电力系统的要求。建立了由高频涌流振荡回路和工频振荡回路组成的容性电流开合试验回路,在试验样机上完成了多组背对背电容器组开合试验,表明双断口真空断路器可显著降低投切电容器组时的重击穿概率。采用合成试验方法对该样机进行了短路电流开合试验,表明双断口真空断路器具有足够的短路开断能力。为保证每个断口的工作负荷相近,对并联均压电容数值的选取进行了试验研究并确定了样机的优选值为400 p F。因此,文中提出的用于投切电容器组的40.5 k V双断口真空断路器设计方案是完全可行的。展开更多
文摘The main purpose of the electrical power system is to transport and distribute energy generated by the central power plants in a safe and reliable manner to the customer premises. Most of the electrical equipment is exposed within the open which suggests they can be vulnerable to lightning strikes, road dwindling, windstorms, and a few engineering activities with the potential of causing different degrees of damage to the electrical equipment. One of the ways to guard the equipment is to deploy switching devices. However, the operations of most of these switching devices produce oscillatory transient in the electrical transmission and distribution systems which result in voltage, current, and frequency fluctuations in the load. This paper investigates the effect of switching devices on power quality and proposes a positive sequence voltage power transient suppression technique that can spontaneously improve the distorted voltage at the instant of capacitor switching using the capacitor line model as a case study. MATLAB/Simulink software was utilized for the analysis on an electrical network model with bus voltages of 69 kV/12.47 kV and 480 V. The results showed that, during switching operations, the positive sequence voltage power detector block produces ripple-free accurate results.
文摘Results of calculation the recovery voltages conditioned by capacitive currents switching-off by high voltage vacuum and auto-compression （SF6） circuit-breakers are presented in the article. The purpose of research was evaluating the maximum values of recovery voltages and also studying the dependence of recovery voltages on some influencing factors, especially on type of circuit-breaker presented in numerical models with its dielectric strength restoration law, chopping current and operation time. The research was carried out with using computer simulation.
文摘针对40.5 k V真空断路器投切电容器组时重击穿概率高这一亟待解决的技术难题,利用串联断口技术实现电容器组电流开合,提出了40.5 k V双断口真空断路器的设计方案并进行了深入研究,以满足电力系统的要求。建立了由高频涌流振荡回路和工频振荡回路组成的容性电流开合试验回路,在试验样机上完成了多组背对背电容器组开合试验,表明双断口真空断路器可显著降低投切电容器组时的重击穿概率。采用合成试验方法对该样机进行了短路电流开合试验,表明双断口真空断路器具有足够的短路开断能力。为保证每个断口的工作负荷相近,对并联均压电容数值的选取进行了试验研究并确定了样机的优选值为400 p F。因此,文中提出的用于投切电容器组的40.5 k V双断口真空断路器设计方案是完全可行的。
