Virtual synchronous coordinate system-based direct power control method of grid-connected inverter

Abstract

The invention provides a virtual synchronous coordinate system-based direct power control method of a grid-connected inverter. The control scheme is implemented in a virtual synchronous coordinate system; a phase angle of a power grid voltage vector does not need to be constantly detected by use of a phase-locked loop; and meanwhile, a current decoupling compensation term related to an inlet inductor is eliminated and the dependency of a control system on inductor parameters is reduced. Meanwhile, the direct power control method has self-adaptive capacity on a power grid frequency deviation, and can be used as supplement and extension of a power grid voltage orientation-based direct power control scheme under the condition that the deviation exists in voltage phase and frequency detection. Furthermore, the virtual synchronous coordinate system-based direct power control method can be used for various forms of PWM power converters of solar energy and biomass energy grid-connected inverters, AC transmission equipment and the like.

Description

technical field [0001] The invention belongs to the technical field of grid-connected inverter control, and in particular relates to a method for direct power control of a grid-connected inverter based on a virtual synchronous coordinate system. Background technique [0002] At present, grid-connected inverters, due to their advantages of high efficiency, low cost, and easy integration, have received extensive attention and a large number of applications in the field of micro-distributed renewable energy generation such as photovoltaics, wind power, micro steam turbines, and energy storage. In recent years, countries have been actively promoting the application of renewable energy, especially the rapid development of wind power and photovoltaic industries, and the proportion of renewable energy generated by wind turbines and photovoltaics in total energy output has increased rapidly. According to the statistics of the National Energy Administration [10-11], by the end of Sep...

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Problems solved by technology

Then, the control scheme is highly dependent on the accuracy of the phase angle obtained by the phase-locked loop. At the same time, because the inductance is in a state of changing from time to time, it is impossible to obtain accurate values, which will cause negative effects on the decoupling control of power.

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