The operation of Voltage Source Inverter (VSI) based active filtering technique can be viewed as compensation for the equivalent harmonic voltage source according to Thevnin theorem. The paper proposes an integrated current control method for PWM-VSI based hybrid fdter, which is a learning control method with incorporation of boost converter technique, to produce the control voltage of PWM inverter. During every learning period, the controller views the PWM-VSI as a boost converter to shape the line current with the achievement of almost unity power factor in the harmonic domain. The repetitive operation of learning control is used to minimize the steady error caused by uncertainties of dynamics of boost converter, the passive fdters connected to power system and the detection of line barmoaic current. A PWM-VSI based hybrid active fdter system consisting of 11" and 13* tuned L-C passive fdters with 12-pulse thyristor rectifier is examined. The simulation and experimental results show the viability and effectiveness of the proposed controller. learning control, boost converter, active

本文介绍了新型电能质量调节器的基本思想及其并联部分析基本原理，控制策略和具体实现，给出了许联有源滤波器的仿真模型以及当PWM脉冲受到批动时的仿真结果。

将供电系统谐波电流的补偿应用戴维南定理等效为谐波电压源的补偿，由此提出了一种基于Boost变换技术的PWM逆变器重复学习控制策略。该控制策略一方面将逆变器视为PWM整流器，应用Boost控制方法，使系统谐波电流与等效谐波电压源形成近似单位功率因数；另一方面，采用内部模型控制将系统谐波电流直接转换形成常规PWM逆变器的控制电压，并且应用重复学习控制消除各种不确定性因素对控制品质的影响。仿真和实验结果证实该控制器适合于有源滤波器系统，并具有跟踪速度快，鲁棒性好、稳态误差小等特点。

运用非线性模糊滑模变结构控制理论，提出了对并联型电能质量调节器进行模糊滑模变结构控制的设计方法。该控制方法能改善系统电能质量的调节，有效地补偿负荷侧谐波电流、无功功率和负序电流。仿真结果表明，该控制规律与常规PI综合控制相比具有较强的实时性和鲁棒性，并能有效改善系统的暂态稳定性。

It is well knowc that accurate measurement of groucding resistance and inductance under impulse voltage is of great importance for safe operation of electrical and electronic equipment. It is the behavior of grounding objects under impulse voltage instead under DC voltage that determine the safe operation of equipment. However, existing method and equipment can not meet the requirement. A new method to realize accurate measurement of grounding impedance and a device, which can produce adjustable wave form of impulse voltage with enough power, can automatically measure and calculate the grounding resistance and inductance, is presented in the paper. The measurement principles, hardware structure and numerical method are described, then the results of experimental results and field measurement results are presented. From these results, we can see that the principle proposed in the paper is correct, the device can meet the requirement of practical measurement, can be used in practical measurement of grounding parameters, which is useful for safe operation of equipment and for economical construction of grounding net.

The theory and modeling of Unified Power Quality Conditioner(UPQC), a FACTS device, is described in this paper. The UPQC proposedin this paper consists of thyristor controlled capacitor banks, series-active filter and shunt-active filter. The series-active and shunt-active filters are developed mainly to compensate negative-sequence current and harmonics as the thyristor controlled capacitor banks is used to compensate the reactive power of power frequency. The functions of the models have been verified. Compensations as well with and without the active filters are discussed in this paper. Some results and corresponding conclusions are presented.

交流电桥是一种高准确度的阻杭测量方法，在许多阻抗测量仪表中有着广泛应用。很长一段时间，人们一直的探索电桥平衡方法以期得到高速度、高准确度、高可靠性的阻抗测量方法[2][3]，1987睥，印度学者提出采用LMS自适应信号处理方法自动平衡数字交流电桥理论[1]，该方法随着计算机及数学信号处理技术的发展具有较广泛的应用前景。本文在文献[1]的基础上，拓宽基于LMS自适应算法的数字交流电桥理论，给出以提高测量频率及多频率测量为目的的阻抗测量方法。

在有源电力滤波器中，直流电压的控制对其补偿效果有重要的影响。由于能量交换以及设备各部分的损耗，直流电压总是存在一定的能量脉动，恶化了谐波补偿效果，传统的增大电容器容量的解决办法增加了装置成本和安装空间。文中以并联有源电力滤波器为例提出一种改进的PWM方法，采用前馈控制消除直流电压波动对变流器输出交流电压的影响，使有源电力滤波器获得了理想的补偿效果。仿真和试验结果证明了该方法的有效性。

从基本的电工理论出发，阐述了三相交流系统谐波、无功和负序综合补偿和有源电力滤波器的原理，提出了一种补偿分量检测方法，即理想传输量分离法，并对这一方法进行了理论分析和实验研究。

首先推导出了a-β坐标系下电压和电流的复坐标表达形式，此表达式数学表达直观，物理意义明确，且可以方便的导出任意单次谐波正负序电流分量的精确检测方法和基波有功电流的精确检测方法。然后，在此基础上得出了a-β坐标系下瞬时无功功率理论与传统功率理论的统一数学描述。最后，对瞬时无功理论的瞬时性和周期性进行了论述。