• Journal of Power Electronics
• /
• v.14 no.1
• /
• pp.105-114
• /
• 2014

The sliding mode control (SMC) strategy is applied to a permanent magnet synchronous machine vector control system in this study to improve system robustness amid parameter changes and disturbances. In view of the intrinsic chattering of SMC, a current sliding mode control method with a load sliding mode observer is proposed. In this method, a current sliding mode control law based on variable exponent reaching law is deduced to overcome the disadvantage of the regular exponent reaching law being incapable of approaching the origin. A load torque-sliding mode observer with an adaptive switching gain is introduced to observe load disturbance and increase the minimum switching gain with the increase in the range of load disturbance, which intensifies system chattering. The load disturbance observed value is then applied to the output side of the current sliding mode controller as feed-forward compensation. Simulation and experimental results show that the designed method enhances system robustness amid load disturbance and effectively alleviates system chattering.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.512-514
• /
• 1997

In this paper, a quasi-sliding mode (QSM) control with load observer is discussed for field-oriented induction motor speed drive. The proposed QSM control, which is defined in the discrete time domain and act with the load torque observer eliminating impacted load torque, restricts the bound of chattering within specified band. With this strategy, we can obtain fast dynamics without overshoot and robustness to parameter variation and disturbance. The proposed scheme is verified by digital simulation.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.4
• /
• pp.513-523
• /
• 2012

For precisely regulating the speed of a permanent magnet synchronous motor system with unknown load torque disturbance and disturbance inputs, an LMI-based sliding mode control scheme is proposed in this paper. After a brief review of the PMSM mathematical model, the sliding mode control law is designed in terms of linear matrix inequalities (LMIs). By adding an extended observer which estimates the unknown load torque, the proposed speed tracking controller can guarantee a good control performance. The stability of the proposed control system is proven through the reachability condition and an approximate method to implement the chattering reduction is also presented. The proposed control algorithm is implemented by using a digital signal processor (DSP) TMS320F28335. The simulation and experimental results verify that the proposed methodology achieves a more robust performance and a faster dynamic response than the conventional linear PI control method in the presence of PMSM parameter uncertainties and unknown external noises.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.150-153
• /
• 2002

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional Pl controller characteristic is affected by variations of load torque disturbance. In the proposed system the speed control characteristic using a feedforward control isn't affected by a load torque disturbance.

• Proceedings of the KIEE Conference
• /
• 1997.07f
• /
• pp.2107-2109
• /
• 1997

Speed sensors are required for the vector control of induction motors. These sensors reduce the sturdiness of the system and make it expensive. Therefore, a drive system without speed sensors is required. Also, the rotor inertia constant, the damping constant and the disturbed load torque of the IM are estimated by the RLS estimator and a torque observer. Then the observed disturbance torque is fed forward to increase the robustness of the IM speed drive.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.12
• /
• pp.3581-3586
• /
• 2009

This paper designed a robust control of an induction motor using a disturbance cancellation observer of a feedforward control. The speed response of conventional PI controller characteristic is affected by variations of load torque disturbance. In the proposed system, the speed control characteristic used a feedforward control which does not undergo the influence of the load torque disturbance. High speed calculation and processing for vector control is carried out by TMS320C31 digital signal processor. Validity of the proposed control method is verified through simulation and experimental result.

• Proceedings of the KIEE Conference
• /
• 1995.11a
• /
• pp.290-292
• /
• 1995

In this paper, the regenerative braking control system for 4 WD Electric Vehicle (EV) is proposed. Many studies on efficient drive of EV are being done to prolong the one charge distance. By using the regenerative braking (REGEN), the resulting EV system has following advantages : a) battery is recharged with the mechanical energy of EV, b) the running load can be reduced, and consequently the efficiency can be increased. The problem of REGEN that the power acceptance ability of battery is limited can be solved by controlling regenerative braking torque. The proposed control system has following characteristics. : a) It controls regenerative power by varying mechanical braking torque. b) It controls mechanical braking torque using load torque observer. c) It controls the regenerative braking torque independently. The control scheme and simulation results are presented for the experimental car.

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.279-282
• /
• 2004

This paper presents load torque observer that is used to deadbeat load torque observer in the induction motor position control system. The simulation has been obtained by simulink. A digital control is composed by trigger method in the continuous block diagram. The results show that proposed system has good effectiveness for the disturbance in induction servo motor system.

• Proceedings of the KIEE Conference
• /
• 1996.07a
• /
• pp.420-425
• /
• 1996

In this paper a robust speed controller for an induction motor is proposed. The speed controller consists or a fuzzy sliding adaptive controller(FSAC) and a sliding mode torque observer(SMTO). FSAC removes the problem or oscillations caused by discontinuous inputs of the sliding mode controller. The controller also provides robust characteristics against parameter and sampling time variations. Although, however, the performance of FSAC is better than PI controller and fuzzy controller in robustness, it generates the problem of slow response time. To alleviate this problem, a compensator, which performs feedforward control using torque signals produced by SMTO, is added. The simulation and hardware implementation results show that the proposed system is robust to the load disturbance, parameter variations, and measurement noises.

• 제어로봇시스템학회:학술대회논문집
• /
• 1999.10a
• /
• pp.185-188
• /
• 1999

An estimation algorithm for vehicle driving load has been proposed in this paper. Driving load is an important factor in a vehicle's longitudinal motion control. An approach using an observer is introduced to estimate driving load based on inexpensive RPM sensors currently being used in production vehicles. Also, a torque estimation technique using nonlinear characteristic functions has been incorporated in this estimation algorithm. Using a nonlinear full vehicle simulation model, we study the effect of the driving load on longitudinal vehicle motion, and the performance of the estimation algorithm has been evaluated. The proposed estimation algorithm has good performance and robustness over uncertainties in the system parameters. An accurate estimate of the driving load can be very helpful in the development of advance vehicle control systems such as intelligent cruise control systems, CW/CA systems and smooth shift control systems.