Background and project objectives
Over the past twenty years, there has been a remarkable transformation in the generation, transmission, and distribution of electric power in Denmark. Prior to 1990, most Danish electric power was produced at large, centralized generation plants from which it was transmitted and distributed to commercial, industrial, and residential consumers. Since then, thousands of generating assets have been installed throughout the Denmark, including dispersed combined heat and power plants and wind turbines. The Cell Controller Pilot Project (CCPP) was initiated to develop and demonstrate the capability to use distributed generation and other energy resources connected to distribution networks for grid reliability and power-flow related applications. Moreover, it was recognized that the coordinated control of local assets such as combined heat and power plants, wind turbines, and load control could mimic the operation of a single large power plant, and therefore provide ancillary services such as power balancing, import/export of active and reactive power, and voltage control at select locations within the distribution system. Lastly, in the event of a transmission system emergency, local distribution networks (60 kV and below) could be rapidly isolated from the transmission network (150 kV and above) and operated autonomously using local resources, thereby reducing the impact on consumers and contributing to more rapid recovery from the emergency. The CCPP set out with these ambitious objectives and successfully developed, deployed and demonstrated in a 1000 km2 pilot study region a control system capable of coordinating distributed energy resources (DER), that managed the assets during normal grid operation, supported multiple ancillary services, facilitated participation in emerging DER market opportunities, and was able to safely island the study region, maintain autonomous operation, and resynchronize with the main network.
Seven year development period
The CCPP project spanned a seven-year period from 2005 through 2011. During the first three years, the field asset capabilities were evaluated and both monitoring and communication equipment were deployed throughout a portion of the pilot study region; the objective was to better understand the generation and loading demands, and to leverage as much of the in situ capabilities as possible. At the same time, a general control strategy was developed and prototyped on a distributed hardware platform, with the proof-of-concept performed using extensive modelling and simulation techniques and live testing at the InteGrid Laboratory.
First live-test in pilot region
During 2008 and 2009, the first fully functional version of the Cell Controller was deployed in a portion of the pilot region. Multiple field tests were performed, including the successful islanding, autonomous operation, and resynchronization of the controlled grid to the main transmission grid. In addition, communication and monitoring capabilities were expanded to the remainder of the pilot region.
Development of advanced simultaneous functionalities
From 2010 through 2011, the Cell Controller capabilities were expanded and capabilities were added to allow multiple stakeholders (the transmission system operator, the distribution network operators, the asset owners and power balancing parties) to perform simultaneous operations. Each new capability was developed and tested both in simulation and at the InteGrid Laboratory before ultimately being successfully demonstrated in the field in Fall 2010 and Spring 2011.
Project documentation and public report
All results achieved was finally incorporated and a complete set of project documentation was produced. The project was finalized end 2011 by issuing a comprehensive Cell Controller Pilot Project puplic report which can be downloaded via the "Read more" box to the right.
The Cell Controller Pilot Project was conducted as an international cooperation between the following parties:
- Syd Energi Net A/S
- Spirae Inc. – USA
- Energynautics GmbH – Germany
- Siemens A/S – Denmark
- 47 Wind-turbine owners
- 5 Local CHP plants