Non-harmonic intelligent frequency conversion controller and control method thereof

Abstract

The present invention discloses a non-harmonic intelligent frequency conversion controller and a control method thereof, and relates to the frequency conversion technology field. The controller mainlycomprises an isolation transformer, a silicon controlled soft starter, an alternating current inductor, a power conversion bridge circuit, a direct current filter capacitor and a control system. Thecontrol system comprises a DSP processor, a single-chip microcomputer processor, a phase-loss detection circuit, a soft-start circuit, a driving protection circuit, an alternating current sampling circuit and a direct current sampling circuit. A mathematical model of a three-phase voltage-type PWM rectifier is established in a three-phase stationary coordinate system, and mathematical models in atwo-phase stationary coordinate system and a two-phase synchronous rotating coordinate system are deduced through coordinate transformation. Through PI regulation current control in the two-phase synchronous rotating coordinate system, a difference between an actual current and a given current is taken as an input of a PI regulator, and an instruction voltage vectors of an alternating current sideof a rectifier is obtained through the PI regulator, thereby controlling the conduction of a power tube, realizing stable operation of a system and improving operation efficiency of the system.

Description

technical field [0001] The invention relates to the technical field of frequency converters, in particular to a control method for a harmonic-free intelligent frequency conversion controller. Background technique [0002] Frequency converters have been around since the 1960s, and have been widely used in major industrialized countries by the 1980s. Well-known companies in the industry mainly include ABB in Switzerland, SIEMENS in Germany, Yaskawa in Japan, Mitsubishi in Japan, and Emerson in the United States. [0003] The initial use of the frequency converter is not for energy saving, but for AC drives instead of DC drives, and to meet the requirements of process control. With the development of automation, power electronics and other technologies, the frequency converter, as the key equipment for motor speed regulation and energy saving, has changed the old mode that the ordinary motor can only run at a constant speed, so that the motor and its driving load can be operate...

AI Technical Summary

Problems solved by technology

[0006] 1) Harmonics cause additional loss of power grid equipment and transmission lines;

[0007] 2) Harmonic current will cause severe distortion of the voltage waveform at the user end, which will cause electrical equipment failure and insulation aging of capacitors, cables and other equipment;

[0008] 3) Harmonics will cause interference to electronic and communication equipment near power equipment, reduce communication quality, or cause communication system disorder

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