Chapter 2. Introduction; Theory Of Operation - Delta 1KVA User Manual

2. INTRODUCTION

2-1 Theory of operation

The main topology of the UPS consists of bypass path, AC-DC converter,
DC-AC inverter, battery charger, DC-DC converter, control circuit and
detection circuit. Moreover, the intelligent power management software is
also optional. The function and efficiency are superior to the traditional UPS.
Description of block diagram
Breaker Relay
EMI
AC-DC Double
AC I/P
Filter
Fig. 2.1 is the hardware block diagram of the UPS.
The UPS operation is described as below:
When the utility power is applied into the UPS, it was divided into two ways
after going through the breaker and EMI filter. One way is connected to
AC-DC converter which converts the utility AC power into a DC voltage which
is called DC-BUS voltage then divide into two path. One path goes to charger
which converts the DC-BUS voltage into a proper DC voltage to charge the
UPS battery. The other path goes into DC-AC half bridge inverter. The other
way works as a bypass path. The bypass relay near the output will choose
either the bypass path or inverter output. In general, the UPS will internally do
the self-diagnosis. If there is no problem, the bypass relay will choose the
inverter output. This is so called【ON-LINE mode】.
BYPASS
PFC Control
LED Board
Circuit
To Control Board
Booster
Battery Bank
Charger DC-DC Converter
To Control Board
Auxiliary
To External Battery Bank Power
3
SHEET 5 TO 6
Control Board
To Auxiliary Power
Half-bridge DC-AC Inverter
To Control Board
BYPASS
RELAY
AC O/P