• Proceedings of the KIEE Conference
• /
• 1993.07b
• /
• pp.724-727
• /
• 1993

This paper is presented real-time digital control techniques of the PWM inverter for UPS. This proposed system is based on instantaneous digital control scheme which is empolyed double dead beat control and prediction method. Especially, to supply the load current from the inverter without the computation delay, the predictive methods are used to generate the load current signal. From the simulation and experimental results, it is shown that presented scheme has good performance such as very low THD of the output voltage, and good dynamic response under the nonlinear load. The experimental implementation of the system is estabilished by using the TMS320C25 DSP.

• Proceedings of the KIPE Conference
• /
• 2001.10a
• /
• pp.146-150
• /
• 2001

A new three-phase soft-switching active front-end inverter is presented. The topology consists of a quasi-resonant PWM boost converter with an additional resonant branch, which provides low loss at high frequency operation. This leads to a high conversion efficiency and a remarkable reduction in the size of the input inductor. To synchronise the PWM pattern with the resonance cycle, a modified space vector modulation with asymmetrical PWM pattern is used. A high power factor can be achieved for both power flow directions. Due to a new control strategy the converter features a low content of harmonics in the line currents even for distorted line voltages.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.11
• /
• pp.861-869
• /
• 2020

A dynamo set for a high-power induction motor drive is expensive and needs a long time to manufacture. Therefore, the development of a simulator that functions as the induction motor and load equipment is required. A load simulator of an inverter for a high-power three-phase induction motor consists of a reactor and three-phase PWM inverter. Therefore, it cannot simulate the dynamic characteristics of an induction motor and functions only as a load. In this paper, a real-time simulator is proposed to simulate a model of an induction motor and the load characteristics based on an LCL filter and three-phase PWM rectifier for a three-phase induction motor. The currents of a PWM inverter that simulate the stator currents of the motor are controlled by the inductor currents and capacitor voltages of the LCL filter. The capacitor voltages of the LCL filter simulate the induced voltages in the stator windings by the rotating rotor fluxes of the motor, and the capacitor voltages are controlled by the inductor currents and a PWM rectifier. The rotor currents, the stator and rotor flux linkages, the electromagnetic torque, the slip frequency, and the rotor speed are derived from the inverter currents and the motor parameters. The electrical and mechanical model characteristics and the operation of vector control were verified by MATLAB/Simulink simulation.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.2
• /
• pp.701-710
• /
• 2017

This paper presents a five-level PWM inverter using series and parallel connection of voltage sources. The alternative connection is done by an auxiliary circuit consisted of a switch, three diodes, and two batteries. The auxiliary circuit is located between input dc voltage source and H-bridge cell. Thanks to the auxiliary circuit, the proposed inverter synthesizes five-level output voltage in an effective way. Topologically both batteries are charged and discharged in the same rate, so it does not need to apply battery voltage balancing control method. Theoretical analysis of the proposed inverter is verified by computer-aided simulation and experiment based on a prototype of 1kW.

• Proceedings of the KIPE Conference
• /
• 2003.07a
• /
• pp.23-26
• /
• 2003

This paper presents a novel hybrid type multilevel inverter in order to improve the waveshape of output voltage. The proposed multilevel inverter is consist of two full-bridge modules for level creation and one full-bridge module for PWM operation. The generated levels are total 11-level: 9-level by the level inverter and 2-level by the PWM inverter. The operational principles and analysis are explained and validity of the proposed system is verified through the experimental results using a prototype.

• Proceedings of the KIEE Conference
• /
• 1991.07a
• /
• pp.568-572
• /
• 1991

This paper describes the three-phase inverter system for 1/2[HP] induction servo motor, using TMS370C050 single-chip microprocessor. The Power MOSFETs are used for PWM inverter circuit because of the advantages such as less harmonic losses and smaller peak current, less torque ripples and noises. Single-chip microprocessor enables the whole controller to be simple and reduced size as well as to more stable and flexible. The basic structures are shown for the power circuit, including the protection and driving circuitry, and the control loops for inverter control functions. The experimental results are given for the prototype PWM inverter system.

• Journal of Power Electronics
• /
• v.11 no.1
• /
• pp.10-15
• /
• 2011

In this paper, a new soft switching three phase inverter with a quasi-resonant dc-link is presented. The proposed inverter has a dc-link switch and an auxiliary switch. The inverter switches are turned on and off under zero voltage switching condition and all auxiliary circuit switches and diodes are also soft switched. The control utilizes PWM and the auxiliary switch does not require an isolated gate drive circuit. In this paper, the operation analysis and design considerations of the proposed soft switching inverter are discussed. The presented experimental results of a realized prototype confirm the theoretical analysis.

• Journal of Power Electronics
• /
• v.12 no.2
• /
• pp.285-293
• /
• 2012

Multilevel inverters have gained attention in high-power applications due to their numerous advantages in comparison with conventional two-level inverters. In this paper a simplified Space-Vector Modulation (SVM) algorithm for a three-level Neutral-Point Clamped (NPC) inverter is implemented on a Freescale$^{(R)}$ DSP56F8037. The algorithm is based on a simplification of the space-vector diagram for a three-level inverter so that it can be used with a two-level inverter. Once the simplification has been achieved, calculation of the dwell times and the switching sequences are carried out in the same way as for the two-level SVM method. Details of the hardware design are included. Experimental results are analyzed to validate the performance of the simplified algorithm.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.28 no.11
• /
• pp.106-111
• /
• 2014

Currently, the commonly used method for PWM(Pulse Width Modulation) Inverter of the Solar Power Plant. However, the limit of the developing performance to the non-linear and switch devices of the Inverter. Therefore, we propose a model predictive control techniques applied to Laguerre functions. LMPC(Laguerre functions model predictive control) reduces the number of computations made and so online implementation becomes possible where traditional MPC would have fail. In this paper, we comment on the appropriate scope and functions degree of the LMPC inverter control. The simulation results from MATLAB are also provided.

• Proceedings of the KIPE Conference
• /
• 2005.07a
• /
• pp.647-650
• /
• 2005

The paper aims on an analysis for dc boost control using Z-source inverter. The modified space vector PWM method is used for controlling both the dc boost and ac output controls in the Z-source inverter. The capacitor voltage and the voltage stress of device with both the shoot-through time and modulation index are analyzed considering the zero state time of inverter. The theoretical analysis is verified with the simulation studies and experiments with 32-bit DSP.