Power Quality Monitoring System Based On LABVIEW

Traditional power quality monitoring and analysis system is always bulky. Because of its bad data process ability and difficulties in upgrading the system, it is not suitable for today’s power quality monitoring. So the power quality monitoring and analysis system based on virtual instrument is introduced in this paper. The paper is divided into six chapters. First of all, it elaborates the conception of power quality and the research and development of the technology in the field of power quality monitoring in recent years both here and abroad. Secondly, the paper studies the measurement methods of the five steady-state power quality and the detection of power transient status. And it focuses on the harmonic measurement method and power transient problems. In the field of harmonic measurement, for the poor accuracy when using FFT algorithm to detect the harmonic component under the circumstances of asynchronous sampling or non-steady signal, an improved FFT algorithm combined with running Fourier series algorithm is proposed to solve the above problem. And it is proved that the method can measure the harmonic component accurate. In the field of detection of power transient status, wavelet transform is used. Because its boundary distortion will disturb the detection of start and end of power transient event, the paper proposed a solve method. And it works correctly. Thirdly, the paper designs and implements a real-time power supply monitoring and analyzing system based on LabVIEW including its basic structure, hardware and software design. It completes the function to measure the steady-state power supply indicators such as voltage, frequency, harmonic, three-phase unbalance, flicker and the detection of transient power disturbance. And useful data provided by the power quality monitoring and analysis system is stored into the database which the user can analyze for further discussion. Finally, the simulated signal is used to test the power supply monitoring system. The results show that the system can work normally and meet the accuracy of the measurement.