ZGR SWIT NG
Operation manual
www.zigor.com
10
3
OPERATION OF ZGR SWIT NG
3.1 Introduction
The
ZGR SWIT NG is a rectifier that guarantees constant output voltage at all times according to model, both in
the presence and absence of the mains network.
When the unit is not supplied with alternating current from the mains network, this continues to supply the load
from a lead or NiCd battery (depending on the model purchased).
The battery will supply the electronics and services, up to its discharge limit. An end of discharge protection is
provided consisting of a relay placed in series with the battery, which avoids any excessive (even destructive)
discharge of the battery. As of this time, the equipment will remain completely out of service as the control is left
without a supply of electricity.
The system will not operate again until the mains electricity is restored under adequate conditions (within the
defined margins).
Fig. 3-1 ZGR SWIT NG block diagram
If we analyse its operation according to each block, see diagram above, we can see that the
ZGR SWIT NG has
an EMI filter (both in its input and output). Its function is to eliminate electromagnetic interferences (both
conducted and radiated), which may cause disturbances in the economic equipment and in the mains network.
After the input EMI filter we find a pre-charge system. This system avoids high peak currents when the equipment
is starting up (inrush current). Once the operating regime has been established, the pre-charge system controlled
by the microswitch board is inhibited, avoiding in this way excessive losses in the pre-charge system.
The second block (rectifier) consists of a bridge complete with diodes. This rectifies the alternating current voltage
from its input in direct current.
The PFC block is a power factor corrector based on BOOST or voltage raising technology. A power factor close to
the unit is obtained with this corrector. A voltage of about 400 VDC is obtained at the output from this block.
The DC-DC converter is based on the FULL BRIDGE topology of Mosfet which switches to 50 Khz. In this way, an
alternating square wave voltage is obtained, corresponding to the isolating transformer input. The secondary
circuit of this intermediate point transformer is rectified and filtered by an LC unit, obtaining an output direct
current and an output voltage with very low ripple.
The
ZGR SWIT NG incorporates a microswitch board capable of controlling the general operation of the system
(PFCcontrol, DC-DC, etc. ), as well as managing all the alarms and events of the system. The control parameters
are defined in the factory.
3.2 Charger
