基于卡尔曼滤波算法的交流零点投切方法

AC zero-point switching method based on Kalman filtering algorithm

同步开关一般采用磁保持继电器作为其机械开关.为了实现开关交流零点时刻精准投切,其微机控制单元必须确定磁保持继电器精确动作时间.然而受到诸如驱动电压、环境温度等因素的影响,机械开关动作时间往往具有很大的不确定性.基于此,针对同步开关中磁保持继电器动作时间测量值的离散性,建立卡尔曼滤波模型,消除动态噪声和测量噪声对过零点投切准确性的影响.通过仿真表明卡尔曼滤波算法能较好地克服磁保持继电器动作时间测量值的离散性,并且通过实验统计验证同步开关交流过零点动作准确性及可靠性,保证同步开关在投切时有效地抑制高频涌流和触头拉弧现象.

Synchronous switch generally uses lathing relay as its mechanical switch.In order to realize accurate switch during AC zero point,its micro controller unit must obtain the precise action time of latching relay.However,affect by many factors such as driving voltage and environment temperature,the action time of mechanical switch usually has uncertainty feature.Aiming at the discrete measurements of latching relay action time,Kalman filtering model is developed to eliminate the dynamic noise and the measurement noise which could affect the accuracy of zero point switching.Simulation results indicate that Kalman filtering algorithm can overcome the discreteness of latching relay action time measurements.Also confirmed by statistical experiment that synchronous switch action precisely and reliably at AC zero point which can ensure the ability of suppressing high frequency inrush current and electric arc.