Special interest in current interruptions is dedicated to the processes close to the current zero instant, the so-called interaction region, which determines the circuit breakers＇ performance. The quantities of inter...Special interest in current interruptions is dedicated to the processes close to the current zero instant, the so-called interaction region, which determines the circuit breakers＇ performance. The quantities of interest in this region are the distribution of temperature, density and pressure, velocity and gas mass flow along the electric arc axis, as well as the distribution of electric stress between contacts Calculation of steady SF_6 gas flow through the nozzle of a 420 kV circuit breaker at the current zero instant, for different arcing durations, was carried out using a commercial CFD （computational fluid dynamics） simulation tool. The calculation results were used to get insight into improvement possibilities of the SF_6 gas flow model used in the software for computer simulation of HV （high-voltage） circuit breakers. Electric field calculation results were performed for the same 420 kV circuit breaker, in order to estimate the breakdown voltage at the current zero instant.展开更多
国际大电网会议CIGRE A3．27工作组“输电等级真空开关设备对电力系统的影响”工作组第二次会议于2010年3月17～19日在西安凯悦（阿房宫）酒店召开。CIGRE的A3．27工作组最初由CIGRE的电流零点俱乐部（Current Zero Club）发起，成立于2...国际大电网会议CIGRE A3．27工作组“输电等级真空开关设备对电力系统的影响”工作组第二次会议于2010年3月17～19日在西安凯悦（阿房宫）酒店召开。CIGRE的A3．27工作组最初由CIGRE的电流零点俱乐部（Current Zero Club）发起，成立于2009年，专题研究“输电等级真空开关设备对电力系统的影响”。展开更多
随着智能电网和电动汽车技术的发展,V2G(vehicle-to-grid)概念受到越来越多的关注,其核心思想在于电动汽车和电网的双向互动,通过调度实现电动汽车的有序充放电,缓和新能源发电接入电网带来的波动,优化电网运行。双向变换器是实现V2G技...随着智能电网和电动汽车技术的发展,V2G(vehicle-to-grid)概念受到越来越多的关注,其核心思想在于电动汽车和电网的双向互动,通过调度实现电动汽车的有序充放电,缓和新能源发电接入电网带来的波动,优化电网运行。双向变换器是实现V2G技术的核心装置,其不仅需要实现能量的双向流动,还要能够控制输入输出的电能质量,这便对变换器的控制提出了更高的要求。针对双向变换器的关键控制技术进行了分析、比较,选取了单极性PWM调制和平均电流控制作为本文所提双向变换器的控制策略;同时就单极性调制下电流过零点畸变的问题进行了理论分析,并且提出了一种改进的过零点控制策略。最后通过一个3 k W的双向AC/DC变换器实验平台证实了所提方法的有效性和可行性。展开更多
文摘Special interest in current interruptions is dedicated to the processes close to the current zero instant, the so-called interaction region, which determines the circuit breakers＇ performance. The quantities of interest in this region are the distribution of temperature, density and pressure, velocity and gas mass flow along the electric arc axis, as well as the distribution of electric stress between contacts Calculation of steady SF_6 gas flow through the nozzle of a 420 kV circuit breaker at the current zero instant, for different arcing durations, was carried out using a commercial CFD （computational fluid dynamics） simulation tool. The calculation results were used to get insight into improvement possibilities of the SF_6 gas flow model used in the software for computer simulation of HV （high-voltage） circuit breakers. Electric field calculation results were performed for the same 420 kV circuit breaker, in order to estimate the breakdown voltage at the current zero instant.
文摘国际大电网会议CIGRE A3．27工作组“输电等级真空开关设备对电力系统的影响”工作组第二次会议于2010年3月17～19日在西安凯悦（阿房宫）酒店召开。CIGRE的A3．27工作组最初由CIGRE的电流零点俱乐部（Current Zero Club）发起，成立于2009年，专题研究“输电等级真空开关设备对电力系统的影响”。
文摘随着智能电网和电动汽车技术的发展,V2G(vehicle-to-grid)概念受到越来越多的关注,其核心思想在于电动汽车和电网的双向互动,通过调度实现电动汽车的有序充放电,缓和新能源发电接入电网带来的波动,优化电网运行。双向变换器是实现V2G技术的核心装置,其不仅需要实现能量的双向流动,还要能够控制输入输出的电能质量,这便对变换器的控制提出了更高的要求。针对双向变换器的关键控制技术进行了分析、比较,选取了单极性PWM调制和平均电流控制作为本文所提双向变换器的控制策略;同时就单极性调制下电流过零点畸变的问题进行了理论分析,并且提出了一种改进的过零点控制策略。最后通过一个3 k W的双向AC/DC变换器实验平台证实了所提方法的有效性和可行性。
