SINAMICS S120 Family for Motor / Generator Island Grid System 

CNC Design has supported FBR from Western Australia to successfully provide a small-scale island grid application on one of their flagship automated robotic construction vehicles. FBR is a pioneering company at the forefront of construction robotics and automation. With a strong focus on innovation, FBR is revolutionizing the construction industry through its visionary technology and cutting-edge solutions.

This project has enabled on board power generation for remote applications and the capability to operate from mains power. This technology has the potential to reshape traditional construction practices, significantly reducing construction timelines and energy costs.

By integrating the latest drive-based technologies from Siemens into FBR's robotic construction solutions, CNC Design has supported FBR in further enhancing the efficiency and capabilities of their automated robotic construction system. This integration of advanced power supply and island grid features will have benefits for sustainable and eco-friendly construction practices.



Small Scale Energy Grid System
Feeding power into a local grid, requires compliance with local power utility grid codes. Complying with these codes requires a complete system with power source, inverters, filters and protective devices and equipment. SINAMICS Active Line Module grid inverters, with their options for riding through and identifying grid faults, reactive power control and measured value acquisition, as well as grid and system protection, include all the important functions that support the certification of a complete system. Complying with limit values for voltage and current harmonics requires grid and EMC filters, which are adapted to address the specific requirements. The SINAMICS S120 Grid Infeed System has various software function modules to manage the fed in power to an island or micro grid.

Grid transformer function module
Is used to magnetize, synchronize and to connect a grid transformer to a power or island grid. In addition, using this function module in conjunction with the Grid Droop Control function module, a black start can be realized for an island grid. This can then be subsequently synchronized to a power grid.

Function module for grid droop control
Enables an island grid to be created. The inverter for grid infeed has the task of controlling the frequency and the voltage in the grid and assumes a ‘grid former’ function.

Function module dynamic grid support
Allows grid faults to be ridden through and allows grid-supporting reactive currents to be injected; this is specified in many grid codes in order to clear short-circuits. Contrary to grid droop operation for island grids, in this particular case, the Active Line Module is operated as grid support element with DC link voltage and grid current control.

Typical applications of grid infeed to generate power.

  • Feeding in power from various DC sources for power grid operation.
  • Battery energy storage systems with the option of island and power grid operation.
  • Hydroelectric turbine and small wind turbine.
  • Application Shaft Generator Drive for use onboard ships.
  • Grid couplings, applications to improve the grid quality.
Example of a micro grids :




CNC Design has developed and tested the first of these micro / island grid systems for FBR in Western Australia. This system can operate as standalone island grid system where the electric motor performs as a generator while being driven by a diesel engine. The SIMOTICS AC motor generates power into the grid and is controlled by the SINAMICS S120 drive system. When connected to mains AC power the system is able to operate in the reverse and is then used like a normal AC drive and motor to drive the on-board hydraulics system. A black start is enabled by providing 24VDC from a battery source, this enables the system to start as a generator when no mains power is available.