Microgrid voltage type self-synchronizing inversion device and method with voltage perturbation estimator

Abstract

The invention relates to a microgrid voltage type self-synchronizing inversion device and method with a voltage perturbation estimator, and belongs to the technical field of microgrids. According to the device and the method, a microgrid inverter can automatically track the amplitude value, frequency and phase angle of grid voltage during grid connection, and the traditional phase-locked loop is not needed, so that the impact current at the moment of grid connection is avoided, and the regulation time can be shortened. When the inverter accesses the microgrid, the self-synchronization operation of the voltage type inverter is realized, and the control effect of plug and play is realized.

Description

technical field [0001] The invention belongs to the technical field of micro-grids, and in particular relates to a micro-grid voltage-type self-synchronous inverter device and method with a voltage perturbation estimator. Background technique [0002] Microgrid is a small power supply and distribution network composed of multiple distributed generation units, multiple inverters, multiple energy storage units and multiple loads, which can realize self-control and self-management; in microgrid, due to the large amount of wind energy The instant insertion and removal of solar power generation units lead to relatively large randomness and fluctuation of electric energy in the micro-grid, and the parameters and structure of the micro-grid have great uncertainty; generally speaking, the capacity of the micro-grid is relatively small, and the inertia is also large. It is relatively small, and the dynamic response is relatively fast. It is a weak grid structure. Therefore, when the ...

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Problems solved by technology

[0004] As the most critical part of the grid-connected control, the performance of the phase-locked loop directly affects the control effect of the entire system, and even affects the stability of the system. Since both the phase-locked loop control system and the microgrid system are nonlinear, it is difficult to adjust The control parameters of the phase-locked loop are used to achieve satisfactory dynamic performance. If the dynamic response of the phase-locked loop is too slow, it will affect the control effect of the system and reduce the stability of the system; especially in the case of a weak micro-grid, there are a large number of high Sub-harmonics affect the phase-locking accuracy of the phase-locked loop, affect the quasi-synchronous control effect, and may even cause system instability

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