Cascaded multi-level tundish electromagnetic heating power supply comprehensive control method

Abstract

The invention discloses a cascaded multi-level tundish electromagnetic heating power supply comprehensive control method. A cascaded multi-level tundish electromagnetic heating power supply is a cascaded full bridge multi-level modularized structure for which the comprehensive control method comprises the following steps: voltage, an input current and a ring current of a three phase power grid are respectively converted to be in a two-phase stationary coordinate system and a three-phase stationary coordinate system; the input current and the ring current are controlled in a dead beat manner, and a balance control strategy is adopted for capacitor voltage in a bridge arm; a quadratic sum and a quadratic difference of upper and lower bridge arm module capacitor voltage in a horizontal direction and a voltage error square of the upper and lower bridge arm module capacitor voltage in a vertical direction are used as voltage control quantity; unbalanced power in a three phase alpha beta 0 stationary coordinate system can be obtained via the voltage control quantity; thus module voltage balance is achieved via control over bridge arm energy. Via use of the cascaded multi-level tundish electromagnetic heating power supply comprehensive control method, rapid tracking control of input and output currents can be realized, control efficiency is improved, and requirements for induction heating power supply energy balance and heavy current rapid transformation are satisfied.

Description

technical field [0001] The invention relates to a comprehensive control method for a cascaded multi-level tundish electromagnetic heating power supply. Background technique [0002] With the advancement of power electronics and semiconductor technology, the emergence of high-power and high-efficiency variable frequency power supplies has greatly promoted the development of induction heating technology for steel heat treatment. The tundish induction heating power supply is used as the medium for its electric energy conversion, and its input current affects the public grid. power quality, and its output current is directly related to the temperature control effect of the tundish, so the research on the control method of the tundish induction heating power supply has good theoretical and engineering significance, and the tundish induction heating system has a great influence on the stability and stability of the power supply energy transmission. High current and fast switching ...

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to provide a cascaded multi-level tundish for realizing the two-way flow of energy between the tundish induction electromagnetic heating power supply and the power grid, solving the problems of the cost and volume of the power supply and the deficiencies of the prior art Including the comprehensive control method of the electromagnetic heating power supply, the cascaded multi-level electromagnetic heating power supply adopts the F-MMC structure, and based on this structure, the problem of fast tracking of the input and output current of the device is solved, and the cascaded multi-level power supply is guaranteed under the premise of a stable control system. The balance of the capacitor voltage of each cascaded module in the electromagnetic heating power supply structure of the level middle package realizes the efficient utilization of the electromagnetic heating power supply energy

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