Electrical Description - Reliance electric GV3000/SE Instruction Manual

Electrical Description

As shown in Figures 2-2, three phase input
power is applied to terminals L1, L2, and L3 via
external standard input fuses or fused isolator.
Power is then fed to the precharge circuitry
through the optional input filter circuit. This filter
keeps conducted
frequency range within the limits as per EMC
product standards. The current transformer T4
senses ground fault currents (on types 038/043
and 058 - 360).
The internal switching power supply develops
the isolated DC 24 V control voltage and
different supply voltages (DC ±5 to 24V) for the
controller operation.
An optional, user supplied AC-line input reactor
allows the Power Module to be operated on any
supply line also with high fault level (refer to
chapter 5, Accessories).
On types GV3000E-AC003 - 030 and 039/044
the inductance of the optional RFI filter allows
connection to supply transformers with a fault
level up to 29 kA (e.g. 1000 kVA) after which a
choke should be fitted.
When line voltage (or DC-bus voltage on type
DC240 and DC360) is applied at the input
terminals (external main contactor has picked
up), the DC-bus begins charging.
The DC-bus voltage increases to a value 1.4
times the no-load three-phase line voltage on
types AC003 - 170 resp. to the value of the
applied DC-voltage on type DC240 and DC360.
Precharge resistors limit the DC-bus capacitors'
charging current. When the DC-bus reaches
95% of its rated voltage, the parallel connected
precharge contactors close and bypass the
resistors.
2-2
emissions in the
2 - DESCRIPTION
On types AC180 - 360 the DC-bus is charged
through a six pulse rectifier bridge controlled by
the pulse firing card FPS.
Discharge resistors on the DC-bus capacitors
can discharge the capacitors down to 50 V
within approximately 60 sec. after power is
high
removed from the input terminals.
The inverter circuitry converts the DC-bus
voltage
frequency at the output to the motor (terminals
U, V, W). The inverter's phase transistors
(IPM, IGBT) are switched by the Gate Driver
cards. Two current transformer devices (T1,T2)
provide current feedback to the regulator
through the Power Interface card. Power output
AC-chokes on types 038/043 and 058 - 360 or
current compound chokes on types 003-030 and
039/044 limit the magnitude of dv/dt in the
motor.
In summary, a constant DC voltage is deve-
loped by rectifying and filtering the incoming AC
power line voltage. A PWM three-phase voltage
is then produced from this constant voltage
using an IGBT inverter corresponding to the
variable voltage and frequency selected for the
motor.
GV3000/SE
into a variable voltage, variable-
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