Design Of Current Data Analyzer For Smart Grid

In the power transmission systems,power quality problems will shorten the life of ordinary electrical equipment,and influence the stability of the power system.Therefore,detection of power quality has become an important part of the smart grid construction. Power quality detection mainly consists of the detection of voltage and current.This thesis designs a current data analyzer which based on the combined power supply of battery and electromagnetic current transformer. The device utilizes a floating-point DSP processor,measures the harmonic currents, inter-harmonic current,and current value contained in the current, and then wirelessly transmits the measurement data to receiving device. Current data analyzer adopts complex modulation Zoom Spectrum Analysis to caculate harmonic and inter-harmonic current value.During the caculation, the tested signal should be extracted by correlation analysis and then calculated by current virtual value. Analyzed and caculated by the cubic spline interpolation function, the current value of the secondary side of electromagnetic current sensor draws much closer to the actual value.In thesis, software and hardware were design for the Current Data Analyzer.Hardware design includes modules like current sampling control circuit, control signal output isolation circuit, analog-digital conversion circuits, power supply circuits, wireless data transmission, taking into account the low power consumption.Software design contains all the programs that operate the current data analyzer and softwares considering low power consumption.The Current Data Analyzer were tested in laboratory. that is added to the harmonics and inter-harmonics with rated frequency amplitude are added into the clean current value to conduct the current detection experiments. Experimental results show that the designed current data analyzer meets the accurate measurement of current values, harmonics and inter harmonics.