基于DSP和ARM的便携继电保护测试仪设计

Design of the Portable Relay Protection Tester Based on DSP and ARM

为了提高继电保护测试仪输出信号的质量和频率分辨率,提出了一种不牺牲每周波拟合点数而使输出信号频率最高至1 000 Hz、频率分辨率达到0.001 Hz的算法。根据需求,DSP计算出波形拟合点和触发时序逻辑信号后,CPLD根据时序信号触发DAC输出波形,波形经功率放大、变压器运放等环节处理,由DSP采集到的反馈信号通过数字PID算法调整,使最终输出信号快速且稳定地达到预设值。测试仪的变压器模块独立化设计,提高了装置的便携性。经检测,该测试仪各项输出满足实际应用要求。

In order to improve the quality and frequency resolution of output signals of the relay protection tester, an algorithm is proposed which makes maximum frequency of the output signals up to 1000 Hz, frequency resolution to 0. 001Hz , without sacrificing the number of fitting points in each cycle. According to the demand,DSP calculates the waveform fitting point and trigger timing logic signals, CPLD triggers DAC output waveform based on the timing signals, then the waveform is disposed by the process of power and transformer operation amplifier, and the feedback signals adopted by DSP are adjusted by the digital PID algorithm, so that the final output signals can rapidly and stably reach the preset value. With the transformer module of the tester being independent, the portability of the device is improved. After testing, each of the output of the tester meets the requirements of practical application.