• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.7
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• pp.352-360
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• 2003

This paper deals with a simple method in order to analyze and compare the harmonic characteristics in the multi-level inverter. Generally, the magnitude of harmonic components becomes different according to the multi-carrier Pulse Width Modulation(PWM) techniques, the modulation index($M_i$) and the switching frequency The previous papers analyzed the harmonic characteristics from the viewpoint of the space voltage vector. Hence, the calculation of the harmonic vector becomes more difficult and complex in 4-level or over 5-level. However, the proposed method has reduced an amount of calculation and simplified the process of it, using the relationship between the reference voltage and the output phase voltage to the load neutral point. It is applied to the 5-level cascade inverter and the harmonic characteristics for each multi-carrier PWM technique are compared through the simulation.

• Journal of Power Electronics
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• v.5 no.2
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• pp.142-150
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• 2005

This paper presents a systematic approach to study the carrier based pulse width modulation (PWM) techniques applied to diode-clamped and cascade multilevel inverters by using multi-modulating patterns. This method is based on the description of controllable redundant parameters in the modulating signals. A unified mathematical formulation is presented for carrier based PWM methods, which obtains outputs similar to the corresponding space vector PWM. A full and separate control of the fundamental voltage, vector redundancies and phase redundancies can be obtained in the carrier based PWM. In this paper, the proposed PWM method and corresponding algorithm for generating multi-modulating signals will be formulated and demonstrated by our simulations.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.4
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• pp.288-295
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• 2010

Multi-level inverters have drawn much of attention in recent years because it can meet the demand of high power applications and good power quality associated with reduced harmonic distortion. As the number of voltage level increases, field programmable gate arrays (FPGAs) are suitable for the implementation of multi-level modulation algorithm. This paper proposes the implementation method for generating PWM pulses at the three phase diode clamped five-level inverter using FPGA. The strategy for communicating stably the data of three-phase reference voltages between the DSP and FPGA is suggested. The techniques for generating PWM signals based on a multi-carrier modulation method are carried out through the experiments with 32-bit DSP and Cyclone-III FPGA.

• Proceedings of the KIPE Conference
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• 2002.11a
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• pp.171-174
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• 2002

This paper deals with a novel method in order to analyze the harmonic characteristics in the multi-level inverter. Generally, the magnitude of harmonic components is different according to the carrier PWM techniques, modulation Index(Mi), and the level of multi-level inverter The previous papers analyzed the harmonic characteristics from the viewpoint of the space vector. Hence, the calculation of the harmonic vector becomes difficult and complex in 4-level or more than S-level. However, the proposed method of this paper reduced an amount of calculation and simplified the process of calculation by using the relationship between reference voltage and output phase voltage to load neutral. This paper analyzed the harmonic and it is applied to the multi-carrier PWM techniques in 5- level and other-level of cascaded inverter system.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.625-629
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• 2004

This paper presents a systematical approach to study carrier based PWM techniques (CPWM) in diode-clamped and cascade multilevel inverters by using a proposed named multi-modulating pattern method. This method is based on the vector correlation between CPWM and the space vector PWM (SVPWM) and applicable to both multilevel inverter topologies. A CPWM technique can be described in a general mathematical equation, and obtain the same outputs similarly as of the corresponding SVPWM. Control of the fundamental voltage, vector redundancies and phase redundancies in multilevel inverter can be formulated separately in the CPWM equation. The deduced CPWM can obtain the full vector redundancy control, and fully utilize phase redundancy in a cascade inverter In this continued part, it will be deduced correlation between CPWM equations in multi-carrier system and single carrier system, present the mathematical model of voltage source inverter related to the common mode voltage and propose a general algorithm for multi-modulating modulator. The obtained theory will be demonstrated by simulation results.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.620-624
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• 2004

Th is paper presents a systematical approach to study carrier based PWM techniques (CPWM) in diode-clamped and cascade multilevel inverters by using the proposed multi-modulating pattern method. This method is based on the vector correlation between CPWM and space vector PWM (SVPWM) and applicable to both multilevel inverter topologies. The CPWM technique can be described in a general mathematical equation, and obtain the same outputs similarly as of corresponding SVPWM. Control of the fundamental voltage, vector redundancies and phase redundancies in multilevel inverter can be formulated separately in the CPWM equation. The deduced CPWM can obtain a full vector redundancy control, and fully utilize phase redundancy in a cascade inverter. In the paper, CPWM equations and corresponding algorithm for generating multi-modulating signals will be performed, in which SVPWM attributes will be presented by corresponding controllable factors.