A Laboratory Setup for Testing Frequency Estimation Algorithms Implemented on Real-Time Target

摘要

In this paper a low-budget single-phase voltage waveform simulator based on the NI PCI-6071E DAQ card and desktop PC with real-time Phar Lap operating system has been presented. Program for generating waveforms in accordance to the IEC standard 61000-4-13, with harmonics of variable frequency, amplitude and phase, has been implemented in the LabViewRt environment. Calibration of DAQ card internal clock has been performed to increase the accuracy of the generated voltage waveform frequency. In order to achieve consistent system operation, DAQ card internal temperature sensor has been used to compensate clock frequency drift caused by local ambient temperature variations. For verification purposes, one of algorithms for the frequency estimation based on the linear Kalman filter has been deployed to target PC. Experimental results in steady-state and dynamics have also been presented. The estimated frequency of the generated signal matches very well with the values obtained by the digital multimeter used for calibration procedure.