Single-current-sensor motor control method based on hybrid pulse width modulation technology

Abstract

The invention discloses a single-current-sensor motor control method based on a hybrid pulse width modulation (PWM) technology. The method comprises the following steps: firstly, constructing two single current sensor circuit topology structures; secondly, keeping the PWM strategies of a sector II and a sector V unchanged, and changing the PWM strategies of a sector I, a sector III, a sector IV and a sector VI; and thirdly, sampling a single current sensor or a single sampling resistor at the acting moments of two voltage vectors in one PWM cycle to obtain the current information of two different phases in any sector, and reconstructing a three-phase winding current according to the condition ia+ib+ic=0 in a star-connected motor. The problem that there is blind area of current reconstruction at the sector boundary is solved. The harmonic of the reconstructed current is reduced. The operation performance of motors is improved. The single-current-sensor motor control method is a low-costand small-size motor driving control strategy.

Description

technical field [0001] The invention belongs to the technical field of motor control, and relates to a motor control method based on hybrid pulse width modulation technology, which can realize vector control of the motor only by needing a current sensor or a sampling resistor. Background technique [0002] Compared with other motors, permanent magnet synchronous motor (PMSM) has the advantages of high reliability, high power density, high control precision, etc., so it is widely used in the fields of CNC machine tools, robot servo control, electric vehicles, military weapons, deep water servo systems, and aerospace Has developed rapidly. [0003] Single current sensor technology, also known as phase current reconstruction technology, is a low-cost permanent magnet synchronous motor drive technology. Its basic principle is to use a current sensor to reconstruct the three-phase winding current of the motor, and then realize the vector control. By adopting this technology, th...

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Problems solved by technology

The DC bus sampling method has a current reconstruction blind zone in the low modulation ratio area of ​​the voltage space vector hexagon and the sector boundary area; the inverter branch sampling method usually uses the Hall current sensor to sample the sum of the two branch currents, Although it can solve the dead zone of the DC bus sampling method, the additional lead wire of this method is very long, which causes signal interference, and the sampling resistor cannot be used to realize

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