Power failure ride-through control method for high-power high-voltage inverter

Abstract

The invention relates to the technical field of electrical energy conversion, in particular relates to a power loss ride-through control method for a high-power and high-voltage inverter. The method comprises the following steps of judging whether an outage grid is in a power loss state or not; if yes, releasing a rotational speed control ring of a vector control system and setting a torque current index value; controlling to stably output DC voltage by using a dual-closed loop control mechanism of a DC voltage outer ring and a torque current inner ring; and judging whether the power grid is recovered or not, if yes, releasing a DC voltage control ring and switching into the rotational speed control ring. By the method, the traditional main circuit topology and hardware parameters are unnecessarily changed, and no device cost is increased; during the whole power loss period, the rotational speed ring is released by a vector control algorithm, the torque current index value is directly set to zero ampere, and a DC under-voltage fault is avoided; and with the adoption of the DC voltage control algorithm, the DC voltage is stabilized by using the inertia energy of a motor rotation shaft, under-voltage protection stop is prevented, and power loss ride-through is achieved.

Description

technical field [0001] The invention relates to the technical field of electric energy conversion, in particular to a power-failure ride-through control method of a high-power high-voltage frequency converter. Background technique [0002] In recent years, the energy problem has attracted great attention from the state. Various electric motor loads are the largest consumers of electric energy and the users with the greatest potential for power saving. Key projects for energy saving and emission reduction. According to the national report "Study on Industrialization Approaches and Countermeasures of Motor Speed ​​Regulation Technology", the total installed capacity of motors in my country has exceeded 580 million kilowatts, and 66% of the total power generation is consumed on motor loads. Since the design of the motor transmission system is to select the motor according to the maximum and the most severe working conditions, this unreasonable design requirement causes the act...

AI Technical Summary

Problems solved by technology

[0003] In the practical application of the speed control system using high-voltage frequency converter, there are the following key problems: due to sudden load changes, various short-term symmetrical or asymmetrical short circuits, etc., the power grid will often have power failures of hundreds of milliseconds or even seconds. According to statistics, the probability of this disturbance occurring in the power supply system is as high as 92% of all fault disturbances

This method is the strongest energy storage in terms of the ability to withstand voltage drops, but from an economic point of view, its cost is too high, which is not conducive to general application

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