With its separate power unit and Control Unit, the SINAMICS S120 drive system can be perfectly adapted to a wide variety of different drive tasks.

The Control Unit is selected according to the number of drives to be controlled and the required performance level, while the power unit must be rated to meet the energy requirements of the system. The connection between the Control Unit and power unit is made very simply using the digital system interface DRIVE‑CLiQ.

Control Units

CU310‑2 PN and SIMOTION D4x5‑2 Control Units

CU310‑2 DP and CU310‑2 PN Control Units

The CU310‑2 Control Unit is used to control a single drive. A PROFIBUS interface (CU310‑2 DP) or a PROFINET interface (CU310‑2 PN) and a TTL/HTL encoder evaluation circuit are standard features.

CU320‑2 Control Unit

The CU320‑2 Control Unit is designed to control several drives. In this case, the following can be operated on a CU320‑2 Control Unit:

• up to 12 drives in V/f control mode or
• up to 6 drives in Servo or Vector control mode.

The CU320‑2 Control Unit can be used to establish links between individual drives and to implement simple technological functions.

SIMOTION D Control Units

SIMOCRANE Basic Technology uses the SIMOTION D435‑2 Control Unit from the SIMOTION Motion Control System product range for the implementation of standard functions and the motion control of all main drives of a crane.

The STARTER commissioning tool is used to commission and diagnose the various Control Units. The SCOUT engineering software, which includes the STARTER tool, is required for SIMOTION D Control Units.

For further information about STARTER, see the section "Engineering software". For further information about the SIMOTION Motion Control System and SCOUT, see the section SIMOCRANE Basic Technology.

Power Modules

The simplest version of a SINAMICS S120 drive system comprises a CU310-2 Control Unit and a Power Module. A line rectifier, a DC link and an inverter for supplying a motor are integrated in the Power Module.

Power Module in blocksize format with CU310-2 Control Unit and BOP20 Basic Operator Panel

Power Modules are designed for single drives which are not capable of regenerating energy to the supply. Generated energy produced during braking is converted to heat via braking resistors.

Power Modules can also be operated via a CU320‑2 Control Unit, a SIMOTION D4x5‑2 or a CX32‑2 Controller Extension, for example, if a single drive is added to a multi‑axis grouping. In this case, the Power Modules in blocksize format must be equipped with the CUA31/CUA32 Control Unit Adapter. This is connected via DRIVE‑CLiQ to the CU320‑2 Control Unit, the SIMOTION D4x5‑2 or the CX32‑2 Controller Extension. Power Modules in chassis format can be directly connected to the Control Unit using a DRIVE‑CLiQ cable.

Motor Modules

A DC link and an inverter for supplying a motor are integrated in the Motor Module.

CU320-2 Control Unit, Line Module and three Motor Modules in booksize format

Motor Modules have been designed for multi‑axis drives. Motor Modules are interconnected by means of a shared DC busbar. Since the Motor Modules share the same DC link, they can exchange energy with one another, i.e. if one Motor Module operating in the generator mode produces energy, the energy can be used by another Motor Module operating in the motor mode. The voltage‑source DC link is supplied with mains voltage by a Line Module.

Line Modules

Line Modules generate a DC voltage from the line voltage and supply Motor Modules with energy via the voltage-source DC link.

Basic Line Modules

Basic Line Modules are designed only for infeed operation, i.e. they are not capable of recovering energy to the line supply. If regenerative energy is produced, e.g. when drives brake, it must be converted to heat by means of a Braking Module and a braking resistor. When a Basic Line Module is used as the infeed, the matching line reactor must be installed. A line filter can be optionally installed in order to ensure compliance with the limits stipulated for Category C2 in EN 61800-3.

Smart Line Modules

Smart Line Modules can supply energy and return regenerative energy to the supply system. A Braking Module and braking resistor are required only if the drives need to be decelerated in a controlled manner after a power failure (i.e. when energy cannot be recovered to the supply). When a Smart Line Module is used as the infeed, the matching line reactor must be installed. A line filter can be optionally installed in order to ensure compliance with the limits stipulated for Category C2 in EN 61800-3.

Active Line Modules

Active Line Modules can supply energy and return regenerative energy to the supply system. A Braking Module and braking resistor are required only if the drives need to be decelerated in a controlled manner after a power failure (i.e. when energy cannot be recovered to the supply). In contrast to Basic Line Modules and Smart Line Modules, however, Active Line Modules generate a regulated DC voltage which remains constant despite fluctuations in the line voltage. In this case, the line voltage must remain within the permissible tolerance range. Active Line Modules draw a virtually sinusoidal current from the supply which limits any harmful harmonics.

In order to operate an Active Line Module, an Active Interface Module with the appropriate rating must be used. A line filter can be optionally installed in order to ensure compliance with the limits stipulated for Category C2 in EN 61800-3.

For further information about configuring a drive system with SINAMICS S120, refer to section configuration notes.

Power Modules, Motor Modules and Line Modules are available in booksize, booksize compact, blocksize and chassis formats:

• Power Modules in blocksize and chassis formats,
• Motor Modules and Line Modules in booksize, booksize compact and chassis formats.

Cooling methods

There are two cooling options available depending on the type of construction:

Internal air cooling

In this standard solution, the power loss from the electronics and power units of the drive components is removed by natural cooling or by a forced‑ventilation system and routed to the interior of the control cabinet.

Liquid cooling

For liquid‑cooled devices in chassis format, the power semiconductors are mounted on a heat sink through which the cooling medium flows. Most of the heat produced by the unit is absorbed by the cooling medium and can be dissipated outside the control cabinet.

Customized application

The devices can be purchased in the different formats as a complete system solution. Users profit from the know-how of the drive experts and need not spend valuable time calculating the thermal design requirements of the application. Especially in applications involving devices with liquid cooling in chassis format, users are provided with a technically sound solution and can reduce their engineering costs. The system solution extends up to complete control cabinets with cooling system and temperature/condensation control.

Further information is available on request.

Energy efficiency

The SINAMICS S120 drive system saves energy by recovering energy from the axes and using it within the DC link group of a multi-axis configuration and by feeding it back into the supply system. Even at full infeed capacity, no unnecessary heat is generated in the control cabinet. Because the Active Line Modules prevent capacitive and inductive reactive currents, SINAMICS S120 also ensures that no unnecessary power losses occur in the power supply and that no current harmonics occur. This not only prevents detrimental effects on other loads, but it also reduces the heat generated in the control cabinet.

System components

System components are divided into the following categories:

• DC link components
  e.g. Braking Modules and braking resistors
• Load-side power components
  e.g. motor reactors
• Supplementary system components
  e.g. Terminal Modules, Operator Panel and Communication Boards
• Encoder system interface
  for connecting various types of encoders to SINAMICS S120

Booksize format

Booksize format units are optimized for multi‑axis applications and are mounted adjacent to one another. The connection for the common DC link is an integral feature. The units are cooled by an internal air cooling circuit.

Booksize compact format

Derived from the booksize format we developed the booksize compact format for machines with particularly high requirements for the compactness of their drives. The booksize compact format offers most features of the booksize format, but with a reduced overall height. The units are cooled by an internal air cooling circuit.

Blocksize format

Blocksize format units are optimized for single-axis applications and are available only as Power Modules.

The CU310‑2 can be directly snap‑mounted. The units are cooled by an internal air cooling circuit.

With the push‑through versions, the Power Module cooling fins extend through the rear panel of the control cabinet, thus facilitating cooling. Push‑through versions should be used in applications where the amount of power loss generated inside the control cabinet itself must be minimized.

Chassis format

Higher‑output units (approximately 100 kW (150 HP) and above) are constructed in chassis format. These are available as Line Modules, Power Modules and Motor Modules. Chassis format units are cooled by an internal air cooling circuit. Liquid‑cooled devices can be ordered for special applications such as extrusion processes or marine engineering. The CU310‑2 Control Unit can be integrated in the Power Modules.

Additional information on liquid‑cooled converters is provided in Catalog D 21.3.