User`s manual

SECTION 5: DS2100 FUNCTIONAL OVERVIEW DS2100 User's Manual
C27750-001 Page 5-7 -
5.3.2 High Voltage Rectification and Filtering
The a.c. mains input is rectified by a three phase diode bridge and filtered by a bank of electrolytic capacitors to
generate the internal DC Bus. This high power d.c. supply is unregulated and will vary in direct proportion with the
a.c. mains input voltage magnitude. The dc bus voltage is monitored continuously and is available for user display,
parameter bus_voltage_actual
(index 0x60F7, subindex18 ). Once the softstart relay has closed, the nominal DC
bus, voltage is set in software, parameter bus_voltage_nominal
(index 0x60F7, subindex 17), which will limit the
maximum speed, at which a motor can rotate.
The software will generate a fault on both undervoltage (F12) and overvoltage (F2) level being detected. The
undervoltage level, parameter bus_under_voltage_limit
(index 0x24A0, subindex 6) is set, by default, to 75% of the
nominal bus voltage. This undervoltage percentage level, parameter bus_under_voltage_limit_percentage
(index
0x24A0, subindex 7) can be changed to different levels to suit application requirements..
The overvoltage level, parameter bus_over_voltage_limit
(index 0x24A0, subindex 5) is typically set by the motor
configuration and will generally be either 400V or 800V.
A.C. Mains Type D.C. Bus Voltage Level
230V Three Phase Mains 325Vd.c.
400Va.c. Mains 565Vd.c.
Table 5.1 Magnitude of the D.C. Bus
5.3.3 Soft Start
Soft start is used to limit the inrush current to the d.c. bus capacitor bank on application of a.c. mains power. This is
intended to prevent nuisance tripping of circuit breakers or blowing of line fuses on power-up.
The soft start relay will close when the monitoring circuit and associated control software determines that the high-
voltage d.c. bus has charged up and the DC bus is at steady state. Softstart will only occur if the DC bus voltage
level is above 70V.