Inverter control method based on voltage feedforward and recombination current control

Abstract

The invention discloses an inverter control method based on voltage feedforward and recombination current control. After signal collection is conducted, reference voltage can be obtained via dead beat control, duty ratio signals of a switch tube can be obtained via sine pulse width modulation or space vector pulse width modulation, and therefore switch-on and switch-off of the switch tube of the inverter can be controlled. According to the inverter control method disclosed in the invention, a predicted voltage value of a common connection point PCC is used as voltage feedforward in a procedure where the reference voltage is obtained via dead beat control, recombination current control is also adopted, an LCL wave filtering device can be prevented from resonance oscillation, and the control precision of a control algorithm can be improved. The control method cannot be affected by power grid voltage distortion, inverter grid connected current control precision can be effectively improved, the robustness of a control system can be improved, and system operation safety and stability can be ensured.

Description

technical field [0001] The invention relates to a control method of a grid-connected converter, in particular to a control strategy based on voltage feed and composite current control. Background technique [0002] In recent years, problems such as energy shortage and environmental pollution have become increasingly serious. Therefore, the development and utilization of new energy sources such as solar energy, wind energy, and hydrogen energy are accelerating day by day, and new distributed power generation technologies are attracting more and more attention. In the distributed grid-connected power generation system, the inverter plays an essential interface between the renewable energy conversion device and the grid, and becomes an extremely important part of the distributed power generation system. At the same time, since a pulse width modulation (PWM) control strategy will generate high-frequency switching harmonics, a filter needs to be used on the AC side for filtering...

AI Technical Summary

Problems solved by technology

However, this control strategy still has some limitations: First, the weighted current feedback control does not directly control the grid-side current, and when the capacitance of the LCL filter is large, there is an obvious error in the grid-side current control

In addition, the increase of LCL capacitance reduces the characteristic frequency of LCL filter resonance

In this specific case, the effectiveness of weighted average current control remains to be verified

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