• Journal of the Korean Institute of Telematics and Electronics B
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• v.28B no.12
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• pp.38-50
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• 1991

A current-controlled scheme of pulse width modulation voltage source inverter (PWM VSI) has attracted considerable attention due to its fast response with current limit and especially suitable for potentially high performance applications such as AC motor drives and UPS systems. These features yield near-sinusoidal currents in the load with reduced current peaks, lower inverter switching frequency and reduce inverter and load stresses. A high performance current-controlled inverter must have a quick response in transient state and low harmonic current in steady state. This paper compares and shows the controlled-characteristics with hysteresis controller(HC), ramp comparison controller(RCC) and predictive controller(PC) of PWM inverter to control actual current of VSI-IM.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.368-371
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• 2000

Two-stage power factor correction (PFC) converter with a single PWM controller is proposed. It consists of a power factor pre-regulator cascaded by an isolated DC/DC converter as in a conventional two-stage approach. However, a single PWM controller is used as in a single-stage, single-switch PFC approach. This converter gives the goof power factor correction, low line current harmonic distortions, and tight output voltage regulations. This converter also has a high efficiency by employing an soft switching method. The proposed approach has advantages such as high performance over the single-stage approach and low cost over two-stage approach. The experimental results obtained on a 300W (30V/10A) prototype PFC converter are given to verify the effectiveness of the proposed control method.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1112-1120
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• 1994

This paper presents a servo control scheme for the surface-mounted permanent-magnet synchronous motor(SPMSM) which essentially uses vector control algorithm. The control system is composed of the PI controller for speed control and the current controller using space voltage vector PWM technique. The high-speed calculation and processing for vector control is carried out by TMS320C31 digital signal processor and IGBT module. The proposed scheme is verified through digital simulations and experiments for 2.2kW SPMSM and shows good dynamic performance.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.976-979
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• 2002

A new controller for switching audio power amplifier with digital PWM input is proposed- Bi-directional Saw-tooth Error Correction (BSEC). This control method for high quality switching amplifier is based on a pulsed edge correction approach using PWM audio signal input as a reference of power switching digital to analog converter. The proposed controller has excellent features such as wide error correction range and no limitation on the modulation index. The controller is implemented in the half-bridge class D amplifier and the performance is verified through hardware experiments. It delivers 100W into 4${\Omega}$ load with less than 0.2% of total harmonic distortion (THD) all over operating range and an maximum efficiency of 82%.

• Proceedings of the KIEE Conference
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• 1997.07f
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• pp.2210-2212
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• 1997

A sensorless input current controller for three phase PWM converter is proposed. A merit of this controller is that sinusoidal input line current, unity power factor, and ripple-free DC voltage can be achieved with low-cost. The paper describes the proposed control strategy and its implementation. Simulation result for the proposed controller is compared with that of the sensor based version.

• Journal of Power Electronics
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• v.4 no.3
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• pp.152-160
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• 2004

This paper presents analysis, modeling, and design of a low-harmonic, isolated, active-clamped SEPIC for future avionics applications. Simpler converter dynamics, high switching frequency, zero voltage-Transition-PWM switching, and a single-layer transformer construction result. This paper describes complete design of a digital controller for a high-frequency switching power supply. Guidelines for the minimum required resolution of the analog-to-digital converter, the pulse-width modulator, and the fixed-point computational unit is derived. A design example based on a SEPIC converter operating at the high switching frequency is presented. The controller design is based on direct digital design approach and standard root-locus techniques.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.29-30
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• 2012

This paper describes a fuzzy PI control method to control the output voltage of three-phase Z-source PWM rectifier. The proposed fuzzy PI controller is a single input fuzzy with its fuzzification, inferences and de-fuzzification processes. The proposed method adjusts the Kp and Ki in real time in order to find the most suitable Kp and Ki for PI controller and to simplify the controller design. The PI portion of DC voltage controller is controlled by fuzzy method. The simulation is performed with PSIM and MATLAB/SIMULINK and is verified the validity of the proposed approach.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.969-972
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• 2000

In this paper, a controller design for brushless linear motor is proposed. 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 using by 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 the brushless linear motor.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.85-89
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• 1998

A switching power stage is a very nonlinear system because it has two or more operation modes in one switching cycle. To model a switching power stage, the state space averaging method has been developed. Though it allows a unified treatment of a large variety of switching power stages, the model it yields is always very nonlinear. So, it is required to linearize the averaged model. But it is well known that a controller for a nonlinear plant designed by the linearization frequently fails in showing satisfactory control performance. Hence it is very natural to try to design a nonlinear controller for a switching power stage. In design of a switching power system, nonlinear control approaches such as adaptive control and fuzzy control have been widely studied so far. In this research, a recently developed control method, time delay control is briefly studied and a design example for a ZVS PWM half bridge converter is given. The performance of the time delay controller is compared to its conventional counterpart, PI controller by computer simulations.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.3
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• pp.141-146
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• 2001

This paper presents a one digital controller two topology PWM DC-DC converter that controls, simultaneously, the separate Buck converter and boost converter with the different specification by using an inexpensive and efficient 8 bit micro-controller. One timer interrupt is used for the detection of output feedback voltage, and other two timer interrupts are used for the generation of PWM waveform for Buck and Boost converter. The control characteristics of one digital controller two topology PWM DC-DC converter is validated by experimental results.