用于电能质量分析的模拟电网信号发生器设计

Design of a generator producing simulated signals of the power grid for power quality analysis

针对现有的电能质量信号发生装置普遍存在的体积大、结构复杂、功能单一、难以实现大功率等缺点,采用电力电子技术和计算机控制技术,设计了一种基于ARM7控制器、主电路用电力电子器件实现的电能质量信号发生器。采用单相交-直-交为主电路结构、正弦脉宽调制(SPWM)为逆变控制策略,并通过闭环控制实现电压的稳定输出。制作了一台单相原理样机进行波形测试,实验结果验证了所采用的控制策略以及软硬件设计的正确性。样机可以按照要求灵活输出电压跌落、电压骤升、电压凹陷、电压中断以及电压谐波等多种电能质量信号波形,具有体积小、结构简单、能实现大功率等特点,可用于实验、教学等场合。

With the help of power elctronics technique and computer control technology,a power quality generator based on ARM7 controller and power electronics components is designed to overcome the common disadvantages of existing power quality generators,such as huge size,intricate structure,simple functions and low power.The singl e-phase AC-DC-AC structure,control tactic of sinusoidal pulse width modulation（SPWM） and close d-loop control to achieve stable output voltage are adopted.Moreove r,a single-phase prototype machine is designed and waveforms are tested.The results of the experiment validate the control tactic,software and hardware design.The prototype machine can generate various kinds of power quality waveforms,such as voltage sags,swells,notches,interruptions and harmonics.It can be applied in teaching and experiments because of its advantages such as small size,simple structure and possibility of achieving high power.