基于FPGA和ARM9的电压波动与闪变测试仪设计

Voltage fluctuation and flicker meter design based on FPGA and ARM9

以嵌入式ARM9控制器和FPGA为处理核心,设计了手持式的电压波动与闪变测试仪,可以同时测量4路交流电压信号的短时闪变值Pst和长时闪变值Plt。为了简化运算过程,对电压每半周波进行一次方均根值运算,并对得到的方均根值序列进行快速傅里叶变换,求解出各频率下对应的瞬时闪变值,并利用概率大值法求解短时闪变。通过在FPGA中的2组存储器交替接收数据,利用乒乓方式实现32位的FFT算法,可大幅提高运算速度与精度。实验结果表明,本测试仪对于方均根值计算精度达到2‰,闪变测量精度达到2%。

The handheld voltage fluctuation and flicker meter based on ARM9 and FPGA is introduced. The meter can measure 4 channels AC voltage signals at thesame time,and the short term severity Pst and long term severity Pit can be calculated. In order to simplify the operation process, the root-mean-square value of each half wave is calculated and a series of RMS value is got. The instantaneous flicker value of each corresponding frequency can be got by the FFT operation to the RMS sequences,and the short term severity Pst is calculated by the method of max probability value. Through the two group of memory in the FPGA alternately receiving data, the 32-bits FFT algorithm using the pingpong mode is realized,and the operation speed and accuracy can be greatly increased. The experiment indicate that the measurement accuracy of RMS value is up to 2% ,and the measurement accuracy of flicker value is up to 2%.