Development of reactive and harmonic current monitoring system

A novel reactive harmonic and current supervision tool was developed based on the conventional current quality monitoring system.The tool is built under Labview environment,aimed at detecting harmonic and reactive current.The system from power grid sampled synchronized voltage and current signals to the main control circuit through Sampling control circuit.Then,an communication platform was established between the upper and the lower computer based on Modbus protocol.In the host computer,the collected data signals were resolved and stored by the test software which was established on the LabVIEW programming environment,and then the resolved signals were displayed on the panel of the virtual instrument in a certain form.The fault was detected,recorded and located by the results of analysis through the test software,the reason leading to the fault point was deeply analyzed in the way of operator watching the playback of the stored data.The experimental results show that the system detects harmonic and reactive current accurately,under the environment of the powerful capabilities of LabVIEW automatic multithreading,the test software can run on low CPU and memory usage,which ensures the date acquisition,analysis,store,display and data query operating orderly and accurately.