Low-voltage ride through control system and method for capacity-optimal energy-storage type double-fed motor

Abstract

The invention relates to a low-voltage ride through control system and a low-voltage ride through control method for a capacity-optimal energy-storage type double-fed motor. The low-voltage ride through control system comprises a power grid, a coupling transformer, a double-fed induction generator (DFIG), a grid-side converter, a rotor-side converter, a DC (Direct Current)-side capacitor, a geared head and a fan, wherein one path of the power grid is directly connected with the DFIG through the coupling transformer, and another path of the power grid passes through the grid-side transformer, the DC-side capacitor and the rotor-side converter in sequence and is connected with the DFIG; a DC-side energy storage device is connected with the DC-side capacitor through a bidirectional DC / DC converter; and the DFIG is connected with the fan through the geared head. The low-voltage ride through control system and method have the advantages of improving the low-voltage ride through capability of a DFIG wind power generation system when the voltage of the power grid sharply drops, ensuring the fault ride-through of the DFIG, improving the supporting capability of the DFID wind power generation system on the voltage of the power grid during fault, providing a measure for reducing the requirement of the DFIG on the capacity of the energy-storage device in the process of realizing the low-voltage ride through and greatly reducing the cost of the energy storage device.

Description

technical field [0001] The invention relates to a doubly-fed wind power generator low-voltage ride-through control system and a control method for reducing the capacity of an energy storage device, in particular to a low-voltage ride-through control system and method for an energy storage doubly-fed wind turbine with optimal capacity. Background technique [0002] Safe and efficient use of wind power has become the most promising way to solve the energy crisis. Among many wind power generation technologies, doubly-fed wind power generation system (DFIG) has become the mainstream technology of modern wind power generation due to its flexible maximum power tracking, decoupling regulation of active power and reactive power. [0003] Since the stator side of the DFIG is directly connected to the grid, it is highly sensitive to the disturbance of the grid. When the grid voltage drops, a DC component will be induced in the stator flux linkage, and an overcurrent will be generated ...

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Problems solved by technology

However, these improved control strategies are difficult for industrial applications due to their complexity, or their robustness is not strong due to the dependence of their algorithms on control parameters.

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