• Journal of Power Electronics
• /
• 제14권6호
• /
• pp.1178-1188
• /
• 2014

This study proposes a finite-state model predictive controller to regulate the load current and balance the DC-link capacitor voltages of a four-leg neutral-point-clamped converter. The discrete-time model of the converter, DC-link, inductive filter, and load is used to predict the future behavior of the load currents and the DC-link capacitor voltages for all possible switching states. The switching state that minimizes the cost function is selected and directly applied to the converter. The cost function is defined to minimize the error between the predicted load currents and their references, as well as to balance the DC-link capacitor voltages. Moreover, the current regulation performance is improved by using a two-step prediction horizon. The feasibility of the proposed predictive control scheme for different references and loads is verified through real-time implementation on the basis of dSPACEDS1103.

• Journal of Power Electronics
• /
• 제15권2호
• /
• pp.299-308
• /
• 2015

This study proposes four novel pulse width modulation (PWM) shoot-through control methods for impedance source (IS) galvanically isolated DC-DC converters. These methods are derived from a PWM control method with shifted shoot-through introduced by the authors in 2012. In contrast to the baseline solution, where the shoot-through states are generated by the simultaneous conduction of all transistors in the inverter bridge, our new approach is based on the shoot-through generation by one inverter leg. The idea is to increase the number of soft-switched transients and, therefore, decrease the dynamic losses of the front-end inverter. All the proposed approaches are experimentally verified through an insulated-gate bipolar transistor-based IS DC-DC converter. Conclusions are drawn in accordance with the results of the switching loss analysis.

• Journal of Power Electronics
• /
• 제9권4호
• /
• pp.535-543
• /
• 2009

In this paper, pulse-width modulation (PWM) control strategy of various topologies of matrix converters is presented, which is based on direct duty ratio PWM (DDPWM). Because the DDPWM method has the characteristics of the inherent per-phase modular structure, it can be effectively applied to single-phase, two-phase and three-phase four-leg matrix converters as well as the common three-phase to three-phase matrix converter. Also, this paper treats command generation method in each matrix converter. The feasibility and validity of the proposed method are verified by experimental results.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.201-203
• /
• 2005

A new 3-phase line-interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) was introduced recently, In this paper, the strategy of voltage control in suggested UPS system is explained. The objective of proposed voltage controllers in parallel(shunt) and series PWM VSC is to guarantee satisfactory characteristics in steady state and transient state.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2018년도 추계학술대회
• /
• pp.173-174
• /
• 2018

This paper proposes the coupled inductor instead of four non-coupled inductors in each leg of the flying-capacitor modular multilevel converter (MMC) to reduce the dimension, weight and cost of the magnetic core. The simulation results have verified the effectiveness of the proposed coupled inductor.

• 전기학회논문지
• /
• 제56권3호
• /
• pp.538-546
• /
• 2007

A new 3-phase line-interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) was introduced recently. In this paper, the strategy of voltage control in suggested UPS system is explained. The objective of proposed voltage controllers in parallel(shunt) and series PWM VSC is to guarantee satisfactory characteristics in steady state and transient state. Therefore the experimental results to prototype UPS system having power rating of 60kVA is shown to prove the verification of voltage control strategy.

• 한국산학기술학회논문지
• /
• 제7권6호
• /
• pp.1072-1077
• /
• 2006

본 논문은 AC 라인 리액터와 2개의 4레그 PWM 전압형 컨버터를 사용하여 병렬 및 직렬 능동필터 기능을 가지는 새로운 3상 Line-Interactive UPS 시스템을 제안하고 전압제어 방식을 설명한다. 제안하는 UPS 시스템의 병렬 및 직렬 PWM 전압형 컨버터에서 전압제어의 목적은 정상상태 및 과도상태에서 만족스러운 동작 특성을 보장하는 것이다.