Simply put, the direct current of the photovoltaic cell is connected to the DC / AC inverter system through DC / DC voltage stabilization, and converted into three-phase power with the same frequency and the same amplitude as the power grid, and then merged into the power grid. In consideration of the cost of the DC voltage stabilization circuit, a Boost boost chopper circuit is generally used. The inverter adopts an IGBT three-phase full-bridge inverter circuit and uses PWM modulation technology for system control.
Because power electronics technology mainly controls the switching tube to achieve system operation, it is inevitable that there will be certain fluctuations. This is inevitable, but this effect can be minimized, such as:
1) Optimize the hardware circuit design
2) The device selection is reasonable (especially the filtering effect of filter capacitor and smoothing reactor)
3) Sampling accuracy calibration in the control program, adjustment of PI parameters
4) In general, the higher the frequency of PWM modulation can also reduce the harmonics to a certain extent
The above is mainly for some aspects of the inverter system, and there are other related anti-disturbance methods on the grid side.
Company： Guangdong Jing Tian new energy electric power Co.,LTD
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