DC lateral voltage controllable 4 quadrant frequency transformer and method thereof

Abstract

The invention provides a controllable four-quadrant frequency converter for voltage on direct current side and a method thereof, so as to realize direct-current voltage control, improve the quality of the current on line side and feedback the regenerative electric energy to an electric network. The controlling circuit of the frequency converter adopts a single processor and an integrated chip to drive a converter on line side and a converter on motor side to alternately fulfill the functions of rectification and inversion under different loaded states. The processer designed by pipelining can quicken the calculation speed and meets the requirement of real time of controlling of the PWM rectifier, due to the adoption of the vector control and power disturbance compensation method, the unity power factor can be realized when the bidirectional flow of the energy is ensured, the voltage on the direct current side can be accurately controlled, when the load is disturbed, the fluctuation range is smaller, the current on direct current side is estimated, the cost of the products can be saved, the estimation method adopts direct direct-current estimation instead of non alternating current estimation, the disturbance compensation fluctuation is reduced, and the system power is more smooth.

Description

technical field [0001] The invention relates to a frequency converter device, in particular to a DC side voltage controllable four-quadrant frequency converter and a method thereof. Background technique [0002] As the driver of the AC motor, the frequency converter is currently recognized as the most ideal speed regulation scheme. Frequency conversion speed regulation has technical characteristics such as wide speed regulation range, high speed regulation precision, good dynamic response, and easy control, and has become the main direction of AC motor speed regulation technology application. At the same time, compared with other methods such as variable resistance and variable voltage, frequency conversion speed regulation has obvious energy-saving effects, especially for variable load applications, such as centrifugal fans, water pumps, etc., and its energy-saving effect is more obvious. Based on the above reasons, frequency conversion speed regulation technology and inve...

AI Technical Summary

Problems solved by technology

[0007] (1) Waste of energy and reduce the efficiency of the system

[0008] (2) The resistance heats up seriously, which affects the normal operation of other parts of the system

[0009] (3) Simple energy consumption braking sometimes cannot suppress the pumping voltage generated by rapid braking in time, which limits the improvement of braking performance (large braking torque, wide speed range, and good dynamic performance)

But it is only an energy feedback device, which cannot improve the harmonic pollution problem of diode rectification, and can not realize the control of DC side voltage, input power factor, etc.

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