Interconnection requirements for distributed electricity generation based on low temperature heat : Mapping of requirements and their possible effects on the HP150

Abstract: The electricity generation is changing. In the grid there is more and more distributed generation installed and the expansion is expected to continue further. The main difference in production of distributed generation units in comparison to a classic power plant is the mass production. In order for distributed generation to be allowed to connect to the public grids, it must fulfil the electrical requirements, the grid code. This thesis is done together with Climeon AB and focuses on what requirements that may apply to an inverter-based drivetrain powered by low temperature heat. By looking at requirements from seven different regions, it can be concluded that the most occurring types of requirements are concerning fault ride-thru, handling of grid frequency fluctuations, reactive power management, power regulation, island mode, DSO or TSO communication, ramp up, automatic reconnection and certification. However, no continuity could be found within the requirements which indicates that in order to comply with the regulations, every local installation must be adapted to the local regulations. The different types of regulations affect an inverter-based drivetrain in multiple ways and it is impossible to say that one requirement will affect the drive train in one specific way. The hardest requirements for a generator unit powered by a low temperature steam cycle are the ones involving islanding and fault ride-thru which requires the drivetrain to instantaneous limit its electricity production. Most of the requirements can be address in the design process by adding electrical inertia and choosing an AFE with a wide operating range.