ABB ACS800 Multidrives Overview
Overview of the Construction
A multidrive is made up of several different units. These sections are called multidrive units. The most important units are:
Inverters have built-in capacitors for smoothing the voltage of the DC busbars. The electrical connection to the common DC busbar is fuse protected. However, an optional fuse switch with a capacitor charging device can be selected to disconnect the whole drive unit. Each inverter has a drive control unit (DCU) which contains the RMIO board and optional I/O modules. Several different I/O extension modules for different functions such as control, monitoring and measurement purposes are available. A separate pulse encoder interface module is also possible. Other optional features include the prevention of unexpected start-up for the inverters to provide a safe interlock for the system.
Diode Supply Unit (DSU)
A diode supply unit is used in non-regenerative drive systems to convert three-phase AC voltage to DC voltage. A 12-pulse bridge configuration can be implemented with the unit supplied by a three-winding transformer with a thirty degree phase shift between secondary windings. A diode supply unit is controlled by an RMIO board similar to drive units and IGBT supply units. This allows parameter setting, monitoring and diagnostic with CDP312R control panel, DriveWindow and fieldbuses.
IGBT Supply Unit (ISU)
An IGBT supply unit is used in regenerative drive systems to convert three-phase AC voltage to DC voltage. In power control it gives the same firm but gentle performance as DTC gives in motor control
The main circuit consists of a main switch, a filter and a converter. The converter is hardware compatible with drive units. The converter can operate in both motoring and generating modes. The DC voltage constant and the line current sinusoidal. The control also provides a near unity power factor. The control performance is excellent due to the ultra-fast control technology, the same as in DTC.
A fully regenerative IGBT supply unit with power factor 1 requires no power compensation. The unit can also boost DC voltage e.g. when the line voltage is low. Harmonic content remains extremely low due to DTC control and LCL filtering.
Thyristor Supply Unit (TSU)
A thyristor supply unit is used in regnerative drive systems to convert three-phase AC voltage to DC voltage. The thyristor supply unit contains two 6-pulse thyristor bridges in antiparallel connection. It has the ability to regenerate back to the mains, providing considerable energy savings with applications having excessive braking powers. A 12-pulse bridge configuration can be implemented with two thyristor supply units supplied by a three-winding transformer. This configuration reduceds harmonics in the supply network.
Paralle Connected Supply Units
It is possible to connect two supply units in parallel to teh same DC bus to get higher power or redundancy. These two units will be located at the rear ends of the drive DC bus. This possibility concerns parallel connection of two diode supply units (DSU+DSU), two IGBT supply units (ISU+ISU), or a DSU and an ISU to the same DC bus.
Higher power is needed, for example, in high power applications where it gives more drive flexibility to connect drive units to the same DC bus, or for high overload requirements.
Redundancy is needed in critical processes and also when maintenance intervals are long
Using DSU+ISU connected in parallel is a solution for when the need for braking power is much lower than for motoring power. ISU is dimensioned for braking power and operates continuously, while DSU is dimensioned for motor power minus ISU power.
In resistor braking whenever the voltage in the intermediate circuit of a frequency converter exceeds a certain limit, a braking chopper connects the circuit to a braking resistor.
Standard braking resistors are separately available in their own cabinets. Non-standard resistors can be used providing that the specified resistance value is not decreased and that the heat dissipation capacity of the resistor is sufficient for the drive application.
AC800M Control Unit (optional)
The multidrive concept also includes the control unit for the AC800M and S800 I/O. The control unit is equipped with communication interfaces, power supplies and the front devices necessary for the automation equipment.
Compact and Complete
- Integration and compact size
- Construction simpler
- Wide range of options available
- Common ABB drive technology
- User-friendly customer interface
- Versatile connections and communications
- Extensive programmability
- Wide power and voltage range
- Wide range of robust enclosures available
- Robust main circuit design
- Extensive protections
- Galvanic isolation of I/O
- All terminals designed for industrial use
- Worldwide approvals: CE, UL, cUL, CSA, C-Tick, GOST R
For Every Application
- DTC, accurate dynamic and static speed and torque control
- DTC - allows high overload-ability and gives high starting torque
- DTC, fast control
- DTC, flux optimization and sophisticated motor model
- DTC, mechanics friendly
- DTC, line supply control
Made by ABB
- Global market leader in AC drives. Long experience.
- World wide service and support network