Motor Control; Product Overview - ABB ACS850 Hardware Manual

22
Component
Braking chopper
Braking resistor
Capacitor bank
du/dt filter
Inverter
Mains choke
EMC filter
Rectifier

Motor control

The motor control is based on direct torque control. Two phase currents and DC link
voltage are measured and used for the control. The third phase current is measured
for earth fault protection.

Product overview

The ACS850-04 is an air-cooled IP20 drive module for controlling AC motors. It is to
be installed into a cabinet by the customer.
The ACS850-04 is available in several frame sizes depending on output power. All
frame sizes use the same control unit (type JCU).
Operation principle and hardware description
Description
Conducts the energy generated by a decelerating motor from the DC bus to a
braking resistor. The braking chopper is built in the ACS850-04; braking
resistors are external options.
Dissipates the regenerative energy by converting it to heat.
Energy storage which stabilizes the intermediate circuit DC voltage.
See page 99.
Converts the DC voltage to AC voltage and vice versa. The motor is controlled
by switching the IGBTs of the inverter.
See page 91.
See page 93.
Converts the three-phase AC voltage to DC voltage.