Virtual synchronous control method for double-fed fan with low-voltage ride through function

Abstract

The invention discloses a virtual synchronous control method for a double-fed fan with a low voltage ride through function. The method is characterized in that the original power and current double closed-loop vector control structure of the fan converter is not changed, and inertia support of grid-connected point frequency and voltage can be realized only by constructing a virtual synchronous control loop. The process is as follows: when the power grid frequency fluctuates or the voltage amplitude drops slightly, the virtual synchronous control loop calculates according to a set droop coefficient to obtain a power compensation instruction, and sets inertia response time through the damping controller and then compensates the power compensation instruction to an original power instructionof the converter. Meanwhile, when the voltage of the grid-connected point drops deeply, the response rate of reactive compensation under the working condition of the fault power grid is improved by automatically adjusting the damping coefficient of the damping controller, and the requirement of the grid-connected standard for the low-voltage ride-through capability of the fan is met.

Description

technical field [0001] The invention belongs to the technical field of doubly-fed induction generator control, and specifically designs a virtual synchronous control method for a doubly-fed fan with a low-voltage ride-through function. Background technique [0002] With the rapid development of renewable energy technology, wind power has become the most competitive and promising new energy production method. Whether it is considered from the perspective of energy security, optimizing energy structure or actively responding to climate change, wind power generation has certain research value and significance. According to the data in the "Global Wind Power Development Report" released by the Global Wind Energy Council in 2018, my country's newly installed wind power capacity is 19.7GW, accounting for about 37% of the world's newly installed wind power capacity. The National Energy Research Institute predicts that by 2030, the installed capacity of wind turbines in my country ...

AI Technical Summary

Problems solved by technology

This method calculates the phase angle through the rotor motion equation. Due to the existence of the moment of inertia and damping, it is equivalent to a slow response to voltage frequency fluctuations, which prolongs the transient process and is not conducive to system stability.

[0010] From the above analysis, it can be seen that no matter whether the VSG is directly controlled or the VSG outer loop control is added, the topology of the traditional vector control of DFIG has been changed, and it cannot be compatible with and improved on the DFIG that has been put into operation.

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