Sampling for multi-channel signals and monitoring for the harmonic of power network

A monitor system is presented in this paper which is used to measure the harmonic voltages and currents of a three-phase source in a power network. In accordance with the principles of harmonic measurement of digital sampling, this system does synchronous sampling for three voltage signals and three current signals analyzing the harmonics. A synchronous sampling impulse circuit is added in hardware to reduce errors caused by leakage effects, and a quasisynchronous sampling algorithm is used in software design. To reduce errors further, the system can monitor and analyze the fundamental wave and harmonics up to the 50^th order in real-time