Double-feed wind power generator low-voltage through control system based on energy storage device

Abstract

The invention relates to a double-feed wind power generator low-voltage through control system based on an energy storage device, which comprises a double-feed motor, a grid side converter, a machine side converter, a voltage detection device, the energy saving device and a low-voltage through control module. The double-feed motor is serially connected to a power grid through the machine side converter and the grid side converter, the energy saving device is connected between the double-feed motor and the power grid, an unloading circuit is parallelly connected between the machine side converter and the grid side converter, the voltage detection device is connected between the power grid and the low-voltage through control module, the low-voltage through module controls the connection andthe disconnection of the energy saving device and the unloading circuit, i.e. the energy is first absorbed by the energy saving device, then the energy is released by the unloading circuit and finally the energy is fed back by the energy saving device, so that the electromagnetic torque, reactive power and the pulse of direct current bus voltage are effectively suppressed, the current of a rotor is limited, required power support is provided when the power grid is recovered, a generator can be always connected with the power grid, and low-voltage through is realized.

Description

technical field [0001] The invention belongs to the technical field of low-voltage ride-through control systems, in particular to a low-voltage ride-through control system of a doubly-fed wind power generating set based on an energy storage device. Background technique [0002] In the future, with the development of the world and China's economy, the consumption of energy will increase sharply, so that our country will face the double pressure of the environment and resources for a long time in the future, and the development of renewable energy including wind power Energy is the ultimate solution to China's energy dilemma. In view of the actual situation of wind power development in China, the coordinated planning and construction of wind farms and power grids is the most critical issue at present. Since wind energy is an uncontrollable and extremely unstable energy source that is intermittent, how to develop wind energy and integrate it into the power grid to ensure the s...

AI Technical Summary

Problems solved by technology

In the process of power grid voltage drop, only improving the control strategy can weaken the transient response of some quantities to a certain extent, but this method is only applicable to the situation of small value grid voltage drop. Once a serious voltage drop occurs, simply relying on Improvement of control strategy is difficult to achieve low voltage ride through

Increase the hardware auxiliary circuit. After the rotor of the double-fed asynchronous motor is connected to the Crowbar device, it runs as a squirrel-cage asynchronous motor and becomes a load that consumes inductive reactive power. Not only can it not support the grid voltage, but it hinders the recovery of the grid voltage after the fault is removed.

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