Offshore Power Electronics

New control systems

The objective has been to provide the required advanced control strategies for grid connected and islanding power electronics converters.

The task has been carried out as a combination of numeric simulations and laboratory demonstrations.

Summary of achievements

New control strategies

Defined a control strategy based on the concept of Virtual Synchronous Machine (VSM) for control of converters integrated in power systems with weak frequency regulation as:
- Control of converters operating connected to grids benefiting from frequency support
- Control of converters operating in islanded grids with presence of synchronous generators
- Control of converters operating in islanded grids dominated by power electronics with low or even zero physical inertia.
Validation of the VSM concept and of its implementation by numerical simulations and on an experimental setup
- Simulations performed in the Matlab Simulink environment
- Experimental tests executed on a 20 kW converter unit while control running on a OPAL-RT platform.

Implementation of converter control algorithms on a FPGA-based processor board

FPGA-based processor board
- Xilinx Virtex5 FX 30 T
- Embedded PowerPC440 core
- 40 MHz , 8 channel, 12 bit AD converter
- 128 MB flash, 256 MB DRAM, 64k Eeprom
- Interface for LEM current transducers
Designed for converter control in drives and grid connected configurations
- Local user interface with display
- CAN-communication for receiving operating modes and references
Operated as general purpose white-box converter controller in the lab