• The Transactions of the Korean Institute of Power Electronics
• /
• v.12 no.5
• /
• pp.364-371
• /
• 2007

This paper deals with filter design for utility-interactive voltage-sourced PWM inverters built by single-phase half-bridge topology. By analyzing the relation between utility voltage and the ac output voltage of single-phase half-bridge inverters, the instantaneous voltage applied on the filter inductor is deduced qualitatively and quantitatively. Moreover, switching ripple current through the filter inductor is calculated from the filter inductor voltage. Based on the above mentioned analysis, filter design method is proposed by evaluating the percentage of the switching ripple current against the rated fundamental current. Proposed filter design method is verified by simulation and experiment.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.12 no.4
• /
• pp.346-353
• /
• 2007

This paper deals with filter design for utility-interactive voltage-sourced PWM inverters built by single-phase full-bridge topology By analyzing the relation between utility voltage and the ac output voltage of single-phase half-bridge inverters, the instantaneous voltage applied on the filter inductor is deduced qualitatively and quantitatively. Moreover, switching ripple current through the filter inductor is calculated from the filter inductor voltage. Based on the above mentioned analysis, filter design method is proposed by evaluating the percentage of the switching ripple current against the rated fundamental current. Proposed filter design method is verified by simulation and experiment.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.55 no.1
• /
• pp.47-53
• /
• 2006

In this paper, a simple scheme compensating for the effect of dc-link ripple voltages on output voltage of two-leg and three-phase PWM inverters is proposed, where single-phase half-bridge PWM convertor and two-leg inverter are used. The voltage at neutral point of the dc-link is controlled so that the upper-half of do-link voltage is equal to the lower-half voltage in average concept. However, the effect of the do-link ripple voltage results in the inverter output voltage and current distortion. This effect can be eliminated by introducing a compensation voltage in switching time calculation. Also, the inverter dead time should be compensated for sinusoidal output waveform. The proposed scheme has been verified by experimental results which were obtained from the V/F constant operation of the induction motor fed by two-leg inverter.

• Journal of Power Electronics
• /
• v.15 no.5
• /
• pp.1227-1234
• /
• 2015

The efficient electric power demand management in electric power supply industry is currently being changed by distributed generation. Meanwhile, small-scale distributed generation systems using renewable energy are being constructed worldwide. Several small-scale renewable distributed generation systems, which can supply electricity to the grid at peak load of the grid as per policy such as demand response programs, could help in the stability of the electric power demand management. In this case, the power quality of the small-scale renewable distributed generation system is more significant. Low prices of power semiconductors and multilevel inverters with high power quality have been recently investigated. However, the conventional multilevel inverter topology is unsuitable for the small-scale renewable distributed generation system, because the number of devices of such topology increases with increasing output voltage level. In this paper, a single-phase multilevel inverter based on H-bridge, with DC_Link divided by bi-directional switches, is proposed. The proposed topology has almost half the number of devices of the conventional multilevel inverter topology when these inverters have the same output voltage level. Double Fourier series solution is mainly used when comparing PWM output harmonic components of various inverter topologies. Harmonic components of the proposed multilevel inverter, which have been analyzed by double Fourier series, are compared with those of the conventional multilevel inverter. An inverter prototype is then developed to verify the validity of the theoretical analysis.

• Proceedings of the KIPE Conference
• /
• 2015.07a
• /
• pp.421-422
• /
• 2015

Nowadays, bidirectional DC-DC converters are becoming more into picture for different applications especially electric vehicles. There are many bidirectional DC-DC converters topologies; however, voltage-fed Dual Half-Bridge (DHB) topology has less number of switches as compared to other isolated bidirectional DC-DC converters. Furthermore, voltage fed DHB has galvanic isolation, high power density, reduced size, high efficiency and hence cost effective. Electrolytic capacitors always have problem regarding size and reliability in DC-AC single phase inverters. Therefore, voltage-fed DHB converter is proposed for the purpose of power decoupling to replace electrolytic capacitor by film capacitors. A new control strategy has been developed for 120Hz ripple rejection, and it was verified by simulation.

• Journal of IKEEE
• /
• v.27 no.4
• /
• pp.450-455
• /
• 2023

Among single-phase photovoltaic inverters that can avoid excessive leakage current caused by the large parasitic capacitance of photovoltaic panels, a boost converter followed by a half-bridge inverter is the simplest and has the smallest leakage current. However, due to the high DC-link voltage, the rated voltage of the switching devices is high and the switching loss is large. This paper proposes a new circuit topology which can operate as a buck-boost inverter by adding two bidirectional switches to the output side of the half-bridge inverter instead of removing the boost converter. By reducing two stages of power conversion through the high-voltage DC-link to one stage, power loss can be reduced without increasing costs and leakage current. The feasibility of the proposed circuit topology is verified by computer simulation and power loss calculation.

• Journal of Power Electronics
• /
• v.15 no.4
• /
• pp.920-928
• /
• 2015

Transformerless solar inverters have a higher efficiency than those with an isolation link. However, they suffer from a leakage current issue. This paper proposes a family of single phase six-switch transformerless inverter topologies with an ac bypass circuit to solve the leakage current problem. These circuits embed two unidirectional freewheeling current units into the midpoint of a full bridge inverter, to obtain a freewheeling current path, which separates the solar panel from the grid in the freewheeling state. The freewheeling current path contains significantly fewer devices and poor performance body diodes are not involved, leading to a higher efficiency. Meanwhile, it is not necessary to add a voltage balancing control method when compared with the half bridge inverter. Simulation and experiments are provided to validate the proposed topologies.

• Journal of Power Electronics
• /
• v.13 no.1
• /
• pp.113-121
• /
• 2013

This paper introduces a simple core loss calculation method for output filter inductor in pulse width modulation (PWM) DC-AC inverter. Amorphous C-core (AMCC-320) is used to analyze the core loss. In order to measure core loss of the output filter inductor and validate the proposed method, a single-phase half-bridge inverter and a calorimeter are used. By changing switching frequency and modulation index (MI) of the inverter, core loss of the AMCC-320 is measured with the lab-made calorimeter and the results are compared with calculated core loss. The proposed method can be easily extended to other core loss calculation of various converters.

• Proceedings of the KIPE Conference
• /
• 2007.07a
• /
• pp.312-314
• /
• 2007

본 논문은 단상하프브릿지 구조를 갖는 계통연계형 전압형 PWM 인버터를 위한 필터설계를 목적으로 한다. 단상하프브릿지 전압형 PWM 인버터의 교류출력단 전압과 계통전압의 관계를 분석하여 필터인덕터에 흐르는 스위칭리플전류의 크기를 정성적 및 정량적으로 구하였다. 이러한 분석을 기초로 하여 계통주입전류의 기본파성분에 대한 스위칭리플전류의 비율을 평가함수로 하는 필터인덕터의 설계법을 제시하였다. 제안된 설계방법을 실험을 통하여 검증한다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.6
• /
• pp.596-603
• /
• 2002

In this paper a new harmonic reduction method of three-phase diode rectifiers is proposed to improve input current performance using the zero-sequence harmonics injection technique. The proposed mothed, based on the third-harmonic injection, employs two half-bridge inverters and two single-phase transformers to independently shape the positive and negative dc rail currents of the diode rectifier. The actively shaped zero-sequence harmonic currents are t]ten circulated through the ac side of the rectifier using a zigzag transformer This results in pure sinusoidal input currents in the three-phase diode rectifier. Experimental results on a 1.5kVA prototype are provided to validate the proposed technique.