Integrated control method of energy feedback frequency converter

Abstract

The invention discloses an integrated control method of an energy feedback frequency converter and relates to a control method of the energy feedback frequency converter. The method comprises the steps of control of a rectification circuit and control of an inversion circuit. According to control of the rectification circuit, direct current side generatrix voltage and grid side line current are detected, grid side voltage and virtual flux linkage are calculated, a power estimator estimates active power and reactive power according to the current and the virtual flux linkage, the active power and the reactive power are converted by a proportional-integral (PI) regulator and coordinates, and a switching signal of an insulated gate bipolar transistor (IGBT) of the rectification circuit is generated by using a space vector modulation technology. According to control of the inversion circuit, the direct current side generatrix voltage and motor stator current are detected, motor stator flux linkage and electromagnetic torque are calculated and converted by the PI regulator and the coordinates, and the switching signal of the IGBT of the inversion circuit is generated by using the space vector modulation technology, so a system works in an expected mode, and control over a motor is realized. The integrated control method of the energy feedback frequency converter has the advantages that the system is high in dynamic performance and static performance, and the performance of the frequency converter is greatly improved.

Description

technical field [0001] The invention relates to a control method of an energy feedback frequency converter, in detail, an energy feedback frequency converter control method with integrated control with good dynamic and static performance. Background technique [0002] With the development of power electronics technology and the promotion of national energy conservation and emission reduction policies, frequency converters, as a product of its development, have been widely used in various industries such as industrial manufacturing, metallurgy, petrochemical and electric power, and play an important role. In particular, the application of energy feedback frequency converter is becoming more and more extensive. [0003] At present, most inverter structures are as follows: figure 1 The shown diode does not control the rectification-DC-inversion structure. This kind of frequency converter has some shortcomings and cannot be used for speed regulation occasions with fast start an...

AI Technical Summary

Problems solved by technology

Constant voltage frequency ratio control is to keep the motor voltage amplitude and frequency ratio at a constant value. This scheme limits the minimum frequency output by the inverter. It is mainly suitable for industrial applications such as fans and blowers. It has limited application range and control performance. Poor and other disadvantages; field-oriented control realizes the decoupling control of flux linkage and torque through coordinate transformation, but requires complex coordinate transformation, which increases the complexity of the system, the system dynamic response is slow, and the system is easily affected by motor parameters during operation. Influence; the direct torque control uses the hysteresis controller to realize the control of the flux linkage and torque, and generates the switching signal of the inverter circuit IGBT through the switch table, resulting in large flux linkage, torque ripple, high current harmonic content, Low-speed performance is not good and switching frequency is not stable, etc.

[0009] To sum up, the motor is in the state of regenerative power generation, and the rectification circuit of the inverter adopts uncontrolled rectification or the existing PWM control method for rectification. Energy waste and other deficiencies; the inverter circuit adopts constant voltage frequency ratio, vector control or existing direct control methods, with limited application range, complex calculation, variable switching frequency and excessive torque ripple

Images