High speed positionless operation technology for three-phase electrical excitation double salient pole motor

Abstract

The invention discloses a high speed positionless operation technology for a three-phase electrical excitation double salient pole motor. Characteristics of a counterelectromotive force change rule are reflected according to end voltages of non-conduction phases of the electrical excitation double salient pole motor. End voltage amplitude values of the motor in high speed operation are firstly identified under three control strategies of constant conduction of a switch tube of a three-phase inverter, PWM wave chopping of an upper tube of the switch tube and PWM wave chopping of a lower tube of the switch tube, the end voltages after sampling filtering are conditioned to 0-3V, coordinate vector transformation is carried out on a basis that a fixed rotation angle alpha does not change along with a rotation speed and the control strategies, and commutation logic is determined by capturing a zero crossing point of the end voltages after the coordinate vector transformation. The high speed positionless operation technology solves problems that a tradition positionless sensor counterelectromotive force method has relatively great phase time-delay, difficult commutation and commutation error caused by direct current bias under different control strategies. The control method provided by the invention is simple and reliable.

Description

technical field [0001] The invention discloses a novel position sensorless control technology for high-speed operation of a three-phase electric excitation double salient pole motor, which belongs to the control technology of power electronics and power transmission systems. Background technique [0002] With the development of power electronics technology and digital control technology, and the three-phase electric excitation double salient pole motor has no winding on the rotor, the structure is simple, the control is flexible, the power density is high, the field can be demagnetized by failure, and the integration of starting and power generation can be realized. The characteristics make the doubly salient motor become a research hotspot in aerospace and other fields. For doubly salient motors, in order to ensure accurate commutation, the use of traditional Hall position sensors on the one hand increases the difficulty of motor installation, and on the other hand greatly ...

AI Technical Summary

Problems solved by technology

At present, the non-position detection technology for doubly salient motors is in the initial research stage. The previously proposed back EMF method uses a Butterworth low-pass filter to low-pass filter the terminal voltage to obtain the base voltage of the non-conducting phase terminal. wave, by identifying the zero-crossing point of the fundamental wave after phase compensation to control the rotor commutation logic. On the one hand, this method needs to design low-pass filters with different cut-off frequencies in different speed ranges, which increases the difficulty of hardware circuit design. On the other hand, On the one hand, the large phase delay angle generated by the Butterworth low-pass filter increases the complexity of the system control

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