Virtual synchronous generator damping winding simulation method based on steady-state frequency difference value compensation

Abstract

The invention discloses a virtual synchronous generator damping winding simulation method based on steady-state frequency difference value compensation. The virtual synchronous generator damping winding simulation method comprises the steps: enabling the damping winding to realize compensation of the difference value of the steady-state output frequency and the reference output frequency for a virtual synchronous generator through an PI regulator; in an island mode, active load fluctuation causes changes of the output frequency of the virtual synchronous generator; taking the difference value of the output frequency and the reference output frequency as the input of the virtual synchronous generator damping winding, taking the damping power which is obtained by multiplying the input with the damping coefficient as the output of the damping winding, wherein during the transient process, the damping power is not zero, so that output of the active power oscillation is restrained; and at the same time, comparing the damping power with the set steady-state damping power reference value 0, and compensating the deviation between the output frequency and the reference output reference through the PI regulator, wherein in the steady-state mode, output of the PI regulator is the difference value between the reference output frequency and the output frequency for the virtual synchronous generator, so that the influence of the damping power on the active power is eliminated.

Description

Technical field: [0001] The invention belongs to the field of virtual synchronous generators, in particular to a virtual synchronous generator damping winding simulation method based on steady-state frequency difference compensation. Background technique: [0002] In recent years, with the rapid development of new energy sources such as photovoltaics and wind power, distributed power generation devices using power electronic inverters as grid-connected interfaces have been widely used. Different from traditional synchronous generators, current grid-connected inverters are usually connected to the grid in current source mode, lacking inertial support and damping for the grid, and unable to participate in the frequency regulation and voltage regulation process of the grid. With the further increase of the penetration rate of distributed renewable energy, it will definitely bring serious challenges to the safe and stable operation of the power grid. As a control technology pro...

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Problems solved by technology

The slope of the static droop characteristic curve of the distributed generation unit is determined according to its own rated capacity. After using the existing damping winding simulation method, the active power output by each distributed generation unit cannot be equally divided according to their respective rated capacities. , causing the capacity of each distributed generation unit to not be fully utilized

The influence of the existing damping winding simulation method on active power droop control can be reduced by reducing the damping coefficient, but a small damping coefficient may lead to oscillation of the output active power

Therefore, although the existing virtual synchronous generator damping winding simulation method can solve the problem of output active power oscillation, it will affect the distribution of steady-state output active power among parallel distributed generation units during island operation

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