• Journal of Power Electronics
• /
• 제9권4호
• /
• pp.582-592
• /
• 2009

This paper proposes a new speed sensorless direct torque and flux controlled interior permanent magnet synchronous motor (IPMSM) drive. Closed-loop control of both the torque and stator flux linkage are achieved by using two proportional-integral (PI) controllers. The reference voltage vectors are generated by a SVM unit. The drive uses an adaptive sliding mode observer for joint stator flux and rotor speed estimation. Global asymptotic stability of the observer is achieved via Lyapunov analysis. At low speeds, the observer is combined with the high frequency signal injection technique for stable operation down to standstill. Hence, the sensorless drive is capable of exhibiting high dynamic and steady-state performances over a wide speed range. The operating range of the direct torque and flux controlled (DTFC) drive is extended into the high speed region by incorporating field weakening. Experimental results confirm the effectiveness of the proposed method.

• International Journal of Control, Automation, and Systems
• /
• 제4권1호
• /
• pp.113-123
• /
• 2006

In this paper, an improved direct torque control (DTC) method for sensorless matrix converter drives is proposed which enables to minimize torque ripple, to obtain unity input power factor, and to achieve good sensorless speed-control performance in the low speed operation, while maintaining constant switching frequency and fast torque dynamics. It is possible to combine the advantages of matrix converters with the advantages of the DTC strategy using space vector modulation and a flux deadbeat controller. To overcome the phase current distortion by the non-linearity of a matrix converter drive, the simple non-linearity compensation method using PQR power theory are presented in the proposed scheme. Experimental results are shown to illustrate the feasibility of the proposed strategy.

• 전기학회논문지
• /
• 제61권10호
• /
• pp.1442-1447
• /
• 2012

In this paper, direct power control system for three-phase PWM AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated flux in the observer. Both active and reactive power calculated using estimated flux. The estimation of flux is performed based on the Reduced-order flux observer using the actual currents and the command control voltage. The source voltage sensors are replaced by a flux estimator. The active and reactive powers estimation are performed based on the estimated flux and Phase anble. The proposed algorithm is verified through simulation and experiment.

• Journal of Power Electronics
• /
• 제13권6호
• /
• pp.1000-1007
• /
• 2013

This paper proposes a sliding-mode-based direct power control (DPC) method in a three-phase boost rectifier without the use of a voltage sensor. This sliding-mode-based DPC is used to improve transient-state response characteristics. This DPC can eliminate voltage sensors by calculating a voltage using a sensorless method, thus considerably reducing cost. This DPC first presents an effective algorithm that does not significantly affect the previous performance and does not need a voltage sensor. Thereafter, the effectiveness of the algorithm is verified by simulations and experiments.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2001년도 전력전자학술대회 논문집
• /
• pp.397-400
• /
• 2001

This paper presents a implementation of digital sensorless position control system of surface permanent-magnet synchronous motor (SPMSM) drive with a direct torque control (DTC). The system are stator flux and torque observer of stator flux feedback control model that inputs are current and voltage sensing of motor terminal with estimated rotor angle for a low speed operating area, two hysteresis band controllers, an optimal switching look-up table, rotor speed estimator, and IGBT voltage source inverter by using fully integrated control software. The developed sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0 (kW) purposed servo drive SPMSM.

• 한국군사과학기술학회지
• /
• 제16권4호
• /
• pp.566-574
• /
• 2013

In this paper, direct power control system for three-phase PFC AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated flux in the observer. Both active and reactive power calculated using estimated flux. The estimation of flux is performed based on the reduced-order virtual flux observer using the actual currents and the command control voltage. Moreover, source voltage sensors are replaced by a estimated flux. DC output voltage has been compensated by DC output ripple voltage estimation algorithm. The active and reactive powers estimation are performed based on the estimated flux and Phase angle. The proposed algorithm is verified through simulation and experiment.

• Journal of Power Electronics
• /
• 제13권3호
• /
• pp.381-389
• /
• 2013

A method to control the speed or the torque of a permanent-magnet direct current motor is presented. The rotor speed and the external torque estimation are simultaneously provided by appropriate observers. The sensorless control scheme is based on current measurement and switching states of power devices. The observers performances are dependent on the accurate machine parameters knowledge. Sliding mode control approach was adopted for drive control, providing the suitable switching states to the chopper power devices. Despite the predictable chattering, a convenient first order switching function was considered enough to define the sliding surface and to correspond with the desired control specifications and drive performance. The experimental implementation was supported on a single dsPIC and the controller includes a logic overcurrent protection.

• 전력전자학회논문지
• /
• 제14권3호
• /
• pp.204-210
• /
• 2009

본 논문에서는 저분해능 위치센서를 갖는 표면부착형 영구자석 동기전동기의 새로운 전류센서 없는 단위 전류당 최대 토크 제어를 제안한다. 영구자석 동기전동기의 수학적 모델로부터 d축 전류를 추정하고, 추정된 d축 전류가 영(零)이 되도록 d축과 q축 전압지령 사이의 위상 각을 제어하여 단위 전류 당 최대 토크 제어를 구현한다. 제안된 방식은 동적 응답 특성이 느린 저가 응용 분야에 적합하다.

• Journal of Power Electronics
• /
• 제14권1호
• /
• pp.125-134
• /
• 2014

This paper presents a robust and speed-sensorless stator flux estimation for induction motor direct torque control. The proposed observer is based on sliding mode approach. Stator electrical equations are used in the rotor orientation reference frame to eliminate the observer dependence on rotor speed. Lyapunov's concept for systems stability is adopted to confine the observer gain. Furthermore, the sensitivity of the observer to parameter mismatch is recovered with an adaptation technique. The nonlinearities of the pulse width modulation voltage source inverter are estimated and compensated to enhance stability at low speeds. Therefore, a new method based on the model reference adaptive system is proposed. Simulation and experimental results are shown to verify the feasibility and effectiveness of the proposed algorithms.

• Journal of Power Electronics
• /
• 제2권2호
• /
• pp.146-153
• /
• 2002

this paper presents an implementation of digital control system of speed sensorless for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The problem of DTC for high-dynamic performance RSM drive is generating a nonlinear torque due to a saturated nonlinear inductance curve with various load currents. The control system consists of stator flux observer, compensating inductance look-up table, rotor position/speed/torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source unverter, and TMS320C31 DSP controller. The stator flux observer is based on the combined voltage and current model with stator flux feedback adapitve control that inputs are the compensated inductances, current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated rotor speed is determined by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operation area. It does not requrie the knowledge of any montor paramenters, nor particular care for moter starting, In order to prove the suggested control algorithm, we have simulation and testing at actual experimental system. The developed sensorless control system is showing a good speed control response characterisitic result and high performance features in 20/1500 rpm with 1.0Kw RSM having 2.57 ratio of d/q reluctance.