Vector control system for high-voltage frequency converter and strategy method thereof

Abstract

The invention discloses a vector control system for a high-voltage frequency converter. The vector control system comprises a high-voltage frequency converter, an asynchronous motor and a controller.The high-voltage frequency converter and the asynchronous motor are electrically connected with each other. The signal input end of the controller is electrically connected to the signal output end ofthe high-voltage frequency converter and the signal input end of the asynchronous motor to acquire current or voltage signals. The signal output end of the controller is electrically connected to thesignal output end of the high-voltage frequency converter to perform pre-excitation control, PI regulation, and voltage feedforward on the current or voltage signals in order to output a pulse widthmodulation signal that enables the high-voltage frequency converter controls the start of the asynchronous motor. The vector control system achieves stable and unimpacted output voltage and current ofthe high-voltage frequency converter and the asynchronous motor speed during the entire start-up process.

Description

technical field [0001] The invention relates to the field of vector control, in particular to a vector control system and a strategy method for a high-voltage frequency converter. Background technique [0002] The application of vector control technology in the high-voltage frequency conversion debugging system is becoming more and more extensive, and the requirements for stability are getting higher and higher. The vector control system is a closed-loop system. If the flux linkage is not established at the initial starting moment, the starting will not be successful, and it may even cause overcurrent damage to the motor. Therefore, pre-excitation technology is the key technology in vector control starting. [0003] According to the type of current, asynchronous motor vector control pre-excitation can be divided into DC pre-excitation and AC AC excitation. DC pre-excitation is to generate a DC current on the three-phase stator through the DC voltage generated by the invert...

AI Technical Summary

Problems solved by technology

However, DC pre-excitation will be affected by switching frequency, filter, etc. During the excitation process, voltage and current may fluctuate greatly, and the magnetic field cannot be stably established.

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