• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.135-137
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• 2007

In this paper, an advanced torque control scheme of SRM using DITC(Direct Instantaneous Torque Control) and PWM(pulse width modulation) is presented. Different from conventional DITC method, proposed method uses one or two switching modes at every sampling time, instead of only one switching mode. The duty ratio of the phase switch is regulated according to the torque error and simple control rules of DITC. Moreover the sampling time of control can be extended, which allows implementation on low cost microcontrollers. The proposed control method is verified by the simulations and experimental results.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.5
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• pp.283-294
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• 2004

This paper introduces the new Direct Torque Control(DTC) method based on the estimated torque in Switched Reluctance Motor(SRM) and applies the proposed DTC to SRM for the instantaneous torque ripple reduction. The nonlinear characteristics of SRM is considered in the calculation of the estimated torque and the theory is described in this paper. Current control is one of the kernel elements of torque controller and the performance of the current control should be high for this work. But the conventional PI current control has a weak point in SRM application because of motional EMF. Consequently, this paper makes up for the weakness of PI controller through present of new current controller, that is termed the non-interference current control. The ability of proposed torque and current controller is verified through simulation and experiment.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.3
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• pp.171-178
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• 2008

Pressure control of hydraulic pump using SRM with pressure predictor and direct torque control method is presented in this paper. Nowadays, high efficiency and high performance motor drive is much interested in hydraulic pump system. But the hydraulic pump system has an inherent defect that its dynamic behavior causes by interaction between the sensor and hydraulic load. It will make low performance of whole system, even unstable and oscillatory. Proposed system integrates pressure predictor and direct instantaneous torque control (DITC). The pressure predictor includes Smith predictor, which is easy to improve unstable or long oscillation in traditional negative feedback control and popular PID control architectures. And DITC method can reduce inherent torque ripple of SRM, and develop smooth torque to load, which can increase stability and improve the torque response of SR drive. So high dynamic performance and stabilization can achieved proposed hydraulic system. At last, the proposed hydraulic system is verified by simulation and experimental results.

• Journal of Electrical Engineering and Technology
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• v.3 no.4
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• pp.538-545
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• 2008

This paper attempts to summarize torque control strategy for high performance SR drive. There are primarily two strategies for torque control. One method is direct torque control, which uses the simple control scheme and hysteresis controller to reduce the torque ripple. Another method is indirect torque control, which uses the complicated algorithms or simple distribution function to distribute each phase torque and obtain current command. The current controller is used to control phase torque by a given current command. In order to compare these two strategies of torque control, five torque control methods are introduced. The advantages and disadvantages of each method are presented. At last, they are verified by some simulations and experimental results.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.336-338
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• 2000

Recently many studies have been performed for variable speed control of induction motor. Direct Torque Control(DTC) is emerging technique for variable speed control of PWM inverter driven induction motor. DTC allows the direct control of stator flux and instantaneous torque through simple algorithm. In this paper ASIC design technique using VHDL is applied to DTC based speed control of induction motor. ASIC for DTC based speed control is designed through the description of coordinate transformation, speed controller stator flux and torque estimator, stator flux and torque controller, stator flux position detector. FSM(Finite State Machine) and inverter voltage switching vector. Finally the above system has been implemented on the FPGA (XC4052XL-PG411). Simulation and experiment has been performed to verify the performance of the designed ASTC.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.208-210
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• 2007

This paper proposes a novel direct instantaneous pressure control(DIPC) of hydraulic pump system with SR drive. And it has very simple control structure, because it doesn’t use any speed and torque control for adjusting pump pressure. The hysteresis band of pressure and proper switching rules can make the actual pump pressure to be constant with fast dynamic response. Therefore, the proposed DIPC method can control of hydraulic pump pressure steadily with fast dynamic response.

• Proceedings of the KIPE Conference
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• 2007.11a
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• pp.163-165
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• 2007

Direct Instantaneous Pressure Control(DIPC) method of SRM using pressure predict method is presented in this paper. A hydraulic pump system has an inherent defect that its dynamic behavior causes by interaction between the sensor and hydraulic load. It will make sometimes the whole system become oscillatory and unstable. Proposed system integrates direct instantaneous torque control (DITC) and Smith predictor to improve dynamic performance and stabilization. The proposed hydraulic oil pump system is verified by computer simulation and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.1
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• pp.23-35
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• 1998

A new instantaneous torque control is presented for a high performance control of a permanent magnet(PM) synchronous motor. In order to deal with the torque pulsating problem of a PM synchronous motor in a low speed region, new torque estimation and cotrol techniques are proposed. The linkage flux of a PM synchronous motor is estimated using a model reference adaptive system technique and the torque is instantaneously controlled by the proposed torque controller combining an integral variable structure control with a space vector PWM. The proposed control provides the advantage of reducing the torque pulsation caused by the non-sinusoidal flux distribution. This control strategy is applied to the high torque PM synchronous motor drive system for direct drive applications and implemented by using a software of the DSP TMS320C30. The simulations and experiments are carried out for this system and the results well demonstrate the effectiveness of proposed control.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.978-980
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• 2000

Sensorless PMSM is much studied for the industrial applications and home appliances because, a mechanical sensor reduces reliability and increases cost. Two types of instantaneous torque controls are basically used for high performance variable-speed a.c. drive : vector control and direct torque control. This paper investigates speed sensorless control of PMSM using direct torque control. The switching of inverter is determined from SVPWM realizing the command voltage which is obtained by flux error and measured current without d-q transformation. The rotor speed is estimated through adaptive observer with feedback loop. The simulation and experimental results indicate good performances.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.3
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• pp.205-212
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• 2007

This paper presents a direct instantaneous torque control (DITC) of Switched Reluctance Motor (SRM) with a novel 4-level converter to develop a uniform torque and to improve a dynamic performance. The DITC method can reduce a high torque ripple of SRM. Drive efficiency and dynamic performance with conventional drive are low due to a slow excitation current build-up. Since the 4-level converter can obtain an addition boosted voltage to have a fast excitation and demagnetization, it can Improve dynamic performance and efficiency easily. To apply the DITC technique to a 4-level converter, a novel control scheme is presented according to the operating modes. Additionally, selection of capacitances of boosted capacitor and efficiency improvement of 4-level converter are analyzed. At last, the validity of proposed method is verified by some computer simulations md comparative experiments.