The PV system is integrated with a low-voltage power network requires an inverter to convert the generated DC voltage by PV systems into AC voltage, and kWh-meter to measure the energy delivered by PV systems to the power grid. The latest generation inverter uses high frequency switching method to reduce the dimension and to improve the efficiency of the inverter. However, this high frequency switching raises the harmonics distortion flowing into the power grid and kWh-meter, and cause significant measurement errors in digital kWh-meter. This study intends to overcome the measurement error by the method of adjusting the frequency of sampling signal in kWh-meter digital with the switching frequency of the inverter. First, kWh-meter tested with a variety of inverter switching frequency to obtain the minimum value of the switching frequency which affected the measurement results of digital kWh-meters. Then kWh-meter measurement results corrected by sampling the signal according to the switching frequency of the inverter. The proposed method is evaluated by simulation LAB-VIEW and confirmed by experimental results. The proposed method is able to maintain the performance of kwh-meters on inverter switching frequency in range 3kHz -150kHz.
|Number of pages||8|
|Journal||Journal of Theoretical and Applied Information Technology|
|Publication status||Published - 1 Jan 2015|
- Digital kWh-meter
- Error measurement
- High switching
- Sampling time