Delta 1KVA - Introduction; Theory of Operation

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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
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
】
.
PFC Control
Circuit
AC-DC Double
Booster
Charger DC-DC Converter
Auxiliary
Power
Half-bridge DC-AC Inverter
Control Board
EMI
Filter
O/P
BYPASS
RELAY
BYPASS
To Control Board
LED Board
To Auxiliary Power
To Control Board
I/P
AC
To Control Board
Battery Bank
To External Battery Bank
Relay
Breaker
AC