• Proceedings of the KIEE Conference
• /
• 1994.07a
• /
• pp.447-449
• /
• 1994

This paper deals with the static characteristics of filters at the AC source in single phase PWM converter using hysterisis current control method. The filters are needed to reduce the current harmonics. In general, there are two kinds of filters which can be used for current controlled PWM converter. One is the low pass filter, the other is the resonant filter for a frequency. This paper designs these filters by analysing the characteristics. And these filters are compared through performance index such as harmonic reduction factor and the value of components which make up filters.

• Journal of Power Electronics
• /
• v.18 no.5
• /
• pp.1325-1335
• /
• 2018

This paper presents a discontinuous pulse width modulation (DPWM) method to reduce switching losses in an indirect matrix converter (IMC) drive. The IMC has a number of power semiconductor switches. In other words, it consists of a rectifier stage and an inverter stage for AC/AC power conversion, which are composed of 12 and 6 switching devices, respectively. Therefore, the switching devices of the IMC suffer from high switching losses in the IMC drives. Various topologies to reduce switching losses have been studied by eliminating a number of switches from the rectifier stage. In this study, in contrast to prior research, a DPWM method is presented to reduce the switching losses of the inverter stage. The effectiveness of the proposed method to reduce switching losses in IMC drives is verified by simulations and experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 1991.10a
• /
• pp.59-63
• /
• 1991

Fuel cells power generating system converts the chemical energy of a fuel directly into electrical energy. The merits of fuel cells power generating system are pollution free and high energy conversion efficiency. Fuel cells power generating system includes the DC/AC converter. DC source obtained from stack is converted to the constant AC voltage or current by the inverter. In this paper, the power conditioner for the fuel cells power generating system are discribed. Some experiments are performed, for the power conversion system. The results show that the implimented experimental system may be applied to the practical fuel cells power generating system.

• Proceedings of the KWS Conference
• /
• 2008.05a
• /
• pp.14-14
• /
• 2008

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.2
• /
• pp.53-57
• /
• 2012

The mathematical model of a three-phase voltage source pulse-width modulation (PWM) DC/AC inverter is non-linear, and in view of the traditional linear control strategy it can not meet the requirements of designing a high-performance inverter. What's more, when the loads are not pure resistive loads, the inverter further requires that the controller possess high-performance. This paper proposes a nonlinear control strategy for the inverter called Passivity-based Control. We can alter the inverter model in three-phase abc coordinate to two-phase synchronous rotating dq coordinate for establishing the port-control Hamiltonian (PCH) model for this system. We can control the distribution of energy in the system to achieve the control aim. Simulation results show that the passivity-based control method can make this system possess a level of high-performance that is both robust and dynamic.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.5 no.6
• /
• pp.592-600
• /
• 2000

In this paper, a novel control scheme of three-phase PWM rectifiers using only dc-side sensors is proposed. The phase currents are reconstructed from switching states of the rectifier and the dc output current. For effective current control, the currents are estimated by a predictive state observer. Also, both the phase angle and the magnitude of the source voltage are estimated by controlling the deviation between the model current and the system current to be zero. The validity of the proposed ac phase and current sensorless technique has been verified by experimental results.

• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.506-509
• /
• 2002

In this paper, a design method of LCL filter at the AC input side of a voltage source PWM converter is proposed. Effective method to prevent pollution of the utility caused by high frequency current ripple is to use a LCL filter instead of the L filter The C elements in the filter provide a low impedance path for the high frequency component, preventing them from entering the utility. A resistor in series with a capacitor is used for damping the resonance in the filter. The design examples are shown and the validity of the proposed design method is verified through the PSIM simulation.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.38 no.5
• /
• pp.370-379
• /
• 1989

This paper describes a three-phase active power filter using voltage-source PWM converter, which can eliminate the harmonics and compensate the reactive power in the ac sides of 6-pulse rectifier. The active filter consists of three-phase PWM inverter and a capacitor, and the hysteresis control technique is used to make the compensating current close to the existing harmonic current and also to improve the response of the filter with simple control circuit. As a result the compensated ac line current becomes sinusoidal and the input power factor is improved roughly to unity.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.463-465
• /
• 2005

This paper proposes a regeneration inverter system, which can regenerate the excessive power form the DC bus line to the AC source for traction systems. The proposed regeneration inverter system for DC traction can reduce harmonics which is a characteristic of the AC current source. The simulation was composed as a prototype model[3.7kW]. Finally, it is shown that the inverter can successfully operate in regeneration mode.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.45-47
• /
• 2005

The Dielectric Barrier micro-hollow cathode structure and it's upper pD limitation are investigated for determining of optimum hollow cathode discharge condition. In experiment, discharge is sustained by AC diriving and investigated gas is pure Xe. From Experiment, Optimum pD range is lower than 0.72 torr.cm at pure Xe and Cu cathode.