Designing an ASIC chip for a power quality monitoring instrument

Power quality (PQ) problems have received wide attention in power systems with non-linear and delicate power loads. To solve the PQ problems, on-line and real-time PQ monitoring is the first task to be done. Serving the purpose, the paper is aimed at implementing an Application specific integrated circuit (ASIC) design in a PQ-monitoring instrument. In the ASIC chip, Fourier-transform processor is designed for harmonic analysis of the voltages and currents monitored on the basis of discrete Fourier transform algorithm. Next, a wavelet-transform processor is developed based on the wavelet-transform algorithm. The processor is intended to fast detect the occurrence of transient signals on the voltage waveform, issuing an alarming signal to the output circuits. Based on the codes of PQ classification, a transient-signal classification processor is finally devised. The processor classifies the transient signals into voltage sag, swell, interruption, and impulse transients, etc., so that the user can be well informed about the PQ problems. Verified by the Workview software, the ASIC has been shown to satisfy the application requirements of on-line and real-time PQ monitoring instrument.