Design of a Smart Meter with Harmonic Analysis Based on the STM32
|Shanghai Jiaotong University
|Power Electronics and Power Drives
|Smart Meter Sigma-Delta Analog to digital converter Harmonic analysis FFT
With the application of power electronics devices, they may produce some harmonics into the grid. Grid harmonics have great effect on energy quality. Development of smart grid requires better smart meters. Besides measuring voltage, current and electrical energy with the using of digital signal processing (DSP) technology smart meter also can analyze the harmonics in grid. There are many organizations studying smart meters, this thesis also studies such smart meters.Volume of current smart meter is big, cost is high , and do not have function of harmonic analysis. This thesis uses a kind of 32-bit modular control unit (MCU)——STM32 as a core of new smart meters. Because STM32 have very strong calculation capability, it makes the new smart meter have function of harmonic analysis.First, this thesis do the analysis of the measuring of voltage and current through the AD conversion, calculation of power and energy value, harmonic analysis, and features such as serial output. Then this thesis proposed an overall design of the smart meter. On the basis author completed the hardware design and made a circuit board. Use of AD converter chip analog signal is sampled by the MCU to achieve the various data. Author also writes a program to calculate the voltage and current value, the power energy value, and do the harmonic analysis. Finally, author does the experiment, applied the smart meter prototype to power grid, do the measurement , calculation and harmonic analysis. Experiment result shows the error of measurement in line with national standards. The scheme of design of smart meter is successful.