Double-conversion UPS Research Articles

단일 스위치 배전압 방식의 단상 PFC 컨버터의 동작 특성

This paper describes the operation characteristic of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS. A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of operation characteristic and controller design has not been known after the converter circuit was proposed. For the performance evaluation of PFC converter, single-phase 3kVA double-conversion UPS was tested. The performance of PFC converter is experimentally confirmed with followings - input current reference traking, input power factor correction.

Integrated auxiliary commutation circuits: a generalised approach

The concept of integrated auxiliary commutation circuits (iACCs) applied to systems with several power conversion stages is proposed. This concept has two main objectives, namely: to reduce the number of additional elements to accomplish the soft-switching and to use the circulating energy from one commutation to assist another one, so that the efficiency is improved without penalising the cost of the system. Some rules to obtain new iACCs are presented. New iZVT circuits are applied to a double-conversion UPS to illustrate the functionality and applicability of this concept. By using these circuits, the main switches operate under soft-commutation of ZVT type, and the auxiliary switches are turned on and off under ZCS or ZVS. Experimental results of three prototypes (1.2 kW at 100 kHz) are presented to demonstrate the good performance of the new integrated ZVT ACC and the feasibility of the proposed concept.

Power in reserve [online double-conversion UPS systems

Against the backdrop of ever increasing power consumption by computers and communication equipments. This paper presents a recent technological developments of modular online double-conversion UPS systems that help UK corporations become more energy efficient.

A High Frequency Transformer Isolation Ups System With 110V/220V Input Voltage

This work proposes an isolated double conversion UPS with power factor correction using a high frequency transformer, and input voltages equal to 110V/220V. The arrangement is suitable to rack structures because it has small size and reduced weight. For both input voltages, the proposed converter has almost the same efficiency processing the same output power. Other relevant features are soft commutation of the controlled switches in the chopper and the boost stage, simple control strategy that can be implemented with well-known integrated circuits, and the use of few batteries in series due to the step-up stage. Qualitative analysis and experimental results obtained from 2kVA laboratory prototype are presented.

Controlador Discreto De Alto Desempenho Com Base Num Modelo Interno Em Eixos Síncronos Para Ups Trifásica Que Satisfaz A Norma Iec62040-3

Este artigo propõe um controlador discreto de tensão em eixos síncronos, baseado num modelo interno com taxa de amostragem e número de pólos reduzidos. Este controlador é apropriado para inversores trifásicos PWM com transformador de saída para aplicações em UPS de dupla conversão. Demonstra-se aqui que esta redução do número de pólos e da taxa de amostragem permite obter alguns benefícios, dentre eles: (i) melhora da resposta transitória; (ii) um incremento da margem de estabilidade do sistema em malha fechada; (iii) uma solução atrativa para microcontroladores e DSPs de aritmética de ponto fixo bem como uma redução do espaço em memória RAM necessário para armazenar o erro da tensão de saída; e (iv) uma solução muito simples para o problema da saturação do transformador isolador. Como resultados obtêm-se tensões de saída de alta qualidade enquanto que se garante um bom desempenho transitório para carga linear bem como não linear. Para confirmar as vantagens anteriormente descritas, resultados experimentais são apresentados sob as condições de teste da norma IEC62040-3, utilizando-se um inversor trifásico com modulação space vector de 10 kVA totalmente controlado por um DSP TMS320F241.