• Journal of Power Electronics
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• v.9 no.2
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• pp.288-299
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• 2009

This paper proposes a feedback linearization control scheme of AC/DC PWM converters with LCL input filters using no damping resisters. Feedback linearization techniques use a transformation from nonlinear system models into equivalent linear models in a simpler form. The feedback linearization scheme in this work has cascade structures unlike usual feedback linearization, therefore it has an advantage that it is possible to limit the capacitor current to a certain level. The performance of the proposed controller is validated with simulation and experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.5
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• pp.420-429
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• 2004

This paper proposes a novel current control strategy on active power filters using PQR instantaneous power theory which can compensate the line current harmonics and the neutral line current under the unbalanced and/or distorted source conditions in three-phase four-wire systems. The characteristics of the inverter ac filters are analyzed and a novel digital controller are proposed to overcome the inherent time delay problem in digital controllers with designed control gain in this paper. The proposed current control method is based on a sinusoidal PWM for fully-digital implementation compared with a conventional hysteresis PWM. PSiM simulation results verify the good performance of the proposed current control strategy on shunt type APFs.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.1954-1956
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• 1997

In this paper, a variable structure current control scheme for field-oriented induction motor drive is presented. The current controller based on space voltage vector PWM scheme consists of feedforward, decouple and variable structure control. The proposed current controller tracks reference value quickly, has robust property against parameter variation and disturbance, reduces switching frequency and improves performance of induction motor drive. Finally, the proposed current controller is verified by digital simulation

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.218-223
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• 1993

In this paper, we present a full digital control scheme which controls currents and speed of the permanent magnet AC servo motor with large range of bandwidth and high performance. The current equations of the permanent magnet AC servo motor are linearized by feedback linearization technique. Both acceleration feedforward terms and IP controllers, whose gains are functions of motor speed, are used in order to control motor currents. In addition the phase delays in current control loops are compensated by placing phase lead-lag compensators after current commands, which make it possible to avoid high gains in the current controllers. Unity power factor can be achieved by the proposed current controller. Pulsewidth modulation is performed by way of the well-known comparison with a triangular carrier signals. The velocity controller is designed on the basis of the linearized model of the permanent magnet AC servo motor by the proposed current controller. The performance of the entire control system is analyzed in the presence of uncertainty in the motor parameters. The proposed control scheme is implemented using the digital signal processor-based controller composed of an Analog Device ADSP 2111 and a NEC78310. The pulsewidth modulation (PWM) signals are generated through a custom IC, SAMSUNG-PWM1, which has the outputs of current controllers as input. The experimental results show that the permanent magnet AC servo motor can be always driven with high dynamic performance by the proposed full digital control scheme of motor speed and motor current.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.8
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• pp.155-160
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• 2002

In this paper, a controller design for brushless linear motor is implemented. The designed controller is mainly composed of current, speed and position controller, which are carried out by the high-speed digital signal processor (DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented by using 32-bit DSP (TMS320C31), a high-integrated logic device (EPM7192), and IPM (Intelligent Power Module) for compact and powerful system design. The experimental results show the effective performance of controller for the brushless linear motor.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.167-169
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• 2001

In this paper, a controller design for high speed and stiffness linear motor is implemented. The designed controller is mainly composed of speed and current controller, which are carried out by the high-speed digital signal processor(DSP). In addition the PWM inverter is controlled by space voltage PWM method. This system is implemented by using 32-bit DSP(TMS320C31), a high-integrated logic device(EPM7128), and IPM(Intelligent Power Module) for compact and powerful system design. The experimental results show the effective performance of controller for high speed and stiffness linear motor.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.53-57
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• 1990

This paper propose Constant Frequency CR-PWM VSI. In which ON/OFF output of Hystersis comparator, which compares the amplitude of reference current with that of actual current, control the switching elements with a constant sampling period of $\mu$-processor. Speed control system of BLDCM driven by controller wi th CF CR - PWM VSI was built.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.224-230
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• 2006

The conventional way to implement a bidirectional converter with boost/buck has been to use two general purpose PWM ICs with a single supply voltage. In this case, when one direction mode is in operation, the other is disabled and the output of the error amplifier of the disabled IC may be saturated to a maximum value or zero. Therefore, during mode transition, a circuit which can disable the switching operation for a certain time interval is required making it impossible to get a seamless transition. In this paper, the limitations of the conventional 42V/14V bi-directional DC/DC converter implemented with general current mode PWM ICs with a single supply voltage are reviewed and a new current mode PWM controller circuit with a dual voltage system is proposed. The validity of the proposed circuit is investigated through simulation. and experiments.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1137-1145
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• 2017

This paper proposes the dead time effect compensation algorithm using proportional resonant controller in pulse width modulation inverter of motor drive. To avoid a short circuit in the dc link, the dead time of the switch device is surely required. However, the dead time effect causes the phase current distortions, torque pulsations, and degradations of control performance. To solve these problems, the output current including ripple components on the synchronous reference frame and stationary reference frame are analyzed in detail. As a results, the distorted synchronous d-and q-axis currents contain the 6th, 12th, and the higher harmonic components due to the influence of dead time effect. In this paper, a new dead time effect compensation algorithm using proportional resonant controller is also proposed to reduce the output current harmonics due to the dead time and nonlinear characteristics of the switching devices. The proposed compensation algorithm does not require any additional hardware and the offline experimental measurements. The experimental results are presented to demonstrate the effectiveness of the proposed dead time effect compensation algorithm.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.7
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• pp.387-398
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• 2002

In this paper, a new Three-Phase Lead-Lag Random Pulse Position PWM(LL-RPWM) scheme is proposed and implemented for decreasing audible acoustic noise of motor drives. In the proposed RPWM(Random PWM), each of three phase pulses is located randomly in each switching interval. Based on the space vector modulation technique, the duty ratio of the pulses is calculated. Along with the randomization of the PWM pulses, we can obtain the effects of spread spectra of voltage, current as in the case of randomly changed switching frequency. To verify the validity of the proposed LL-RPWM, the simulation and experimental study was tried. Along with the randomization PWM pulses, the space vector modulation is also executed in the C167 micro-controller. The simulation and experimental results show that the voltage and current harmonics are spread to a wide band area and that the audible acoustic noise is reduced by the proposed RPWM method.