简单分析了电动助力转向(EPS)系统的结构与工作原理,介绍了EPS系统无刷直流电机(brushless DC motor,BLDC motor)的电路构成和控制方法。设计开发了采用单片机进行控制,车载蓄电池供电,用MOSFET构成的三相逆变器驱动的EPS控制系统的电...简单分析了电动助力转向(EPS)系统的结构与工作原理,介绍了EPS系统无刷直流电机(brushless DC motor,BLDC motor)的电路构成和控制方法。设计开发了采用单片机进行控制,车载蓄电池供电,用MOSFET构成的三相逆变器驱动的EPS控制系统的电控单元(ECU)。详细介绍了硬件电路和软件的设计,最终通过EPS台架实验,验证了所采用的PWM控制策略对EPS系统助力转向过程的有效控制。该系统实现简单,具有较强的实用性和经济性。展开更多
There are two different definitions for specifying the mean effective ion charge Zeff in plasmas： a） from the Spizer electrical resistivity of the plasma and b） from bremsstrahlung radiation losses of the plasma. I...There are two different definitions for specifying the mean effective ion charge Zeff in plasmas： a） from the Spizer electrical resistivity of the plasma and b） from bremsstrahlung radiation losses of the plasma. In this paper Zeff in the centre of tokamak ohmic discharges has been determined from information on sawtooth-relaxations of the steady state plasma, based on the analysis for the power balance of the plasma electrons in the plasma centre during the period of recovery after the sawtooth crashes. This method is found to supply reliable results for tokamak parameters. While its application requires some efforts in data analysis, it can provide a reliable determination of Zeff, independent of the information from bremsstrahlung radiation losses of the plasma.展开更多
A new mothod was presented to find the optimal location and parameter setting of Thyristor Controlled Series Compensator (TCSC) to maxmize the transfer capability.Firstly the sensitivity of the transfer capability wit...A new mothod was presented to find the optimal location and parameter setting of Thyristor Controlled Series Compensator (TCSC) to maxmize the transfer capability.Firstly the sensitivity of the transfer capability with respect was described to the line's reactance was described to find the more sensitive lines for installing TCSC,however,the line which has the most sesitivity value is always not the best line for installing TCSC.For solving this problem,the more sensitive m lines were selected as the alternative line group of installing TCSC,and then modified particle swarm optimization (MPSO) was used to find out the optimal location and the optimal parameter settings of TCSC.Particle swarm optimization (PSO) algorithm can results premature convergence.For solving this problem,population entropy and cellular automata were introduced to it.Simulation results of IEEE 30-bus system proved the effectiveness of the method and its application values.展开更多
文摘简单分析了电动助力转向(EPS)系统的结构与工作原理,介绍了EPS系统无刷直流电机(brushless DC motor,BLDC motor)的电路构成和控制方法。设计开发了采用单片机进行控制,车载蓄电池供电,用MOSFET构成的三相逆变器驱动的EPS控制系统的电控单元(ECU)。详细介绍了硬件电路和软件的设计,最终通过EPS台架实验,验证了所采用的PWM控制策略对EPS系统助力转向过程的有效控制。该系统实现简单,具有较强的实用性和经济性。
基金Project supported by the Nuclear Science Foundation （Grant No1997517）.
文摘There are two different definitions for specifying the mean effective ion charge Zeff in plasmas： a） from the Spizer electrical resistivity of the plasma and b） from bremsstrahlung radiation losses of the plasma. In this paper Zeff in the centre of tokamak ohmic discharges has been determined from information on sawtooth-relaxations of the steady state plasma, based on the analysis for the power balance of the plasma electrons in the plasma centre during the period of recovery after the sawtooth crashes. This method is found to supply reliable results for tokamak parameters. While its application requires some efforts in data analysis, it can provide a reliable determination of Zeff, independent of the information from bremsstrahlung radiation losses of the plasma.
基金Sponsored by the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No. 20050213006)
文摘A new mothod was presented to find the optimal location and parameter setting of Thyristor Controlled Series Compensator (TCSC) to maxmize the transfer capability.Firstly the sensitivity of the transfer capability with respect was described to the line's reactance was described to find the more sensitive lines for installing TCSC,however,the line which has the most sesitivity value is always not the best line for installing TCSC.For solving this problem,the more sensitive m lines were selected as the alternative line group of installing TCSC,and then modified particle swarm optimization (MPSO) was used to find out the optimal location and the optimal parameter settings of TCSC.Particle swarm optimization (PSO) algorithm can results premature convergence.For solving this problem,population entropy and cellular automata were introduced to it.Simulation results of IEEE 30-bus system proved the effectiveness of the method and its application values.
