Jui-Ling Chen

An IPMSM position control system using high frequency injection sensorless technique

This paper proposes a high performance sensorless interior permanent magnet synchronous motor control system using a high frequency injection technique. A new estimation method which uses both the high-frequency d-axis current and q-axis current to estimate the rotor position is investigated. By using the proposed method, the hypothesis-synchronization signal used in the conventional high frequency injection method can be eliminated. A 1.25 kHz, 15V, sinusoidal waveform voltage is injected into the d-axis synchronous frame of the motor, and then the high frequency d-axis and q-axis currents can be measured to determine the rotor position of the motor. By using this new method, the estimation rotor position error is within ±2 electrical degrees. A sensorless position control system is implemented by using the high frequency injecting technique. The system can achieve precise position control with satisfactory performance.

A wide-range adjustable speed control method for multi-motor drive systems

This paper proposes a new control method for a multi-motor drive system to increase its output torque capability and extend its operating speed range. When the drive system is operated below rated speed, the motors are parallel operated to increase total output torque. By suitably distributing the stator currents based on an optimal efficiency algorithm, the output torque can be effectively increased. On the other hand, when the drive system is operated beyond rated speed, one motor is operated at a standstill and its stator inductances are used as three-phase inductances of an boost converter; moreover, an interleave control algorithm is used for the boost converter to reduce the input current ripples. The other motor is used as a driving motor. By using this method, an extended speed, which can reach twice the rated speed range with a near constant torque, is obtained. No field weakening is required. This paper proposes a new control method for a multi-motor drive system, which can be applied to electric vehicle drive systems.

Predictive controller design for a sensorless IPMSM speed control system

This paper proposes a predictive controller design for a sensorless interior permanent magnet synchronous motor drive system. The controllers include a current-loop predictive controller and a speed-loop predictive controller with an external load estimator. In addition, the estimated error of the rotor position estimator is reduced due to the using of the on-line tuning stator resistance and q-axis inductance. By using the proposed control algorithms, the closed-loop sensorless interior permanent magnet synchronous motor drive system can achieve fast transient responses, satisfactory load disturbance responses, and good tracking responses. A digital signal processor, TMS 320F2812, is used to perform the rotor position estimating algorithm and the predictive control algorithm. As a result, the hardware is very simple. Experimental results can validate the theoretical analysis and show that the predictive controllers have better performance than the PI controllers.

Sensorless IPMSM position control system using a high frequency injection method

This paper proposes a sensorless IPMSM position control system based on a high frequency injection method. The proposed method uses 12-bit low resolution A/D converters to covert the stator currents of the IPMSM. In addition, a 0.67kHz injection voltage, which has a 30 V amplitude, is used. By measuring the stator currents, the injection current components related to the injection voltage can be obtained. Then an estimation method is proposed to obtain the estimated rotor position. After that, a compensation algorithm related to the saturation of the mutual inductance is implemented to reduce the rotor position estimation margin of error. Finally, a closed-loop system based on the high frequency injection method is implemented. Measured results show the proposed method can achieve satisfactory performance with a margin of error of only ±4 degree.

Implementation of an integrated battery-charger for an electric-propulsion system

This paper proposes an integrated battery-charger for an electric-propulsion system. The system includes a rectifying diode bridge, an inverter, a motor, a digital signal processor, a battery set, and three relays. By suitably controlling the three relays and the switching states of the inverter, the proposed system can be operated either an electric propulsion system or a charger. Moreover, the charger can be operated as a boost converter or a buck converter. The input power factor is higher than 0.9, which can meet the IEC 1000-3-2 standard. Only three additional relays are required and the windings of the motor are connected. A digital signal processor, TMS-320-F-2808, is used to execute all of the control algorithms. As a result, the hardware circuit is quite simple. The volume and cost of the proposed system can be reduced when compared the traditional charger with a traditional propulsion system. Experimental results can validate the theoretical analysis and show the correctness and feasibility of the proposed method.