Power System Control and Analysis

Recent developments in power semiconductor materials are also exploited by the use of silicon carbide semiconductor devices which can reduce power losses in the energy conversion process, thereby increasing efficiency. Increases in conversion efficiency also mean reductions in unwanted generated heat, which in turn reduces heatsink sizes, reduces electronic component temperatures and improves reliability.

Power electronics team development of the smart DC converters and controllers for energy distribution of the future as part of the SOLCER DC house project. The system allows for the comprehensive per second metering and monitoring for real time views of energy.

Smaller, lighter and more energy-efficient power converters for renewable energy sources have been developed as part of the SPARC project. These converters take advantage of developments in the module integration technology to reduce the footprint of power semiconductors used in the energy conversion process and enable significant size and weight reductions to be made.

As part of the SPARC research programme, the power electronic team looked at the possibility of exploiting PV inverters to support local voltage through exchanging reactive power with the grid.

As penetration of distributed generation increases, the electrical distribution networks may encounter several challenges mainly related to voltage control. The situation may deteriorate in case of a weak grid connected to an intermittent source such as photovoltaic (PV) generation. Fast varying solar irradiance can cause unacceptable voltage variations that may not be easily compensated by slow-responding utility equipment such as Capacitor banks and Transformers’ tap changer.

The PV inverter can be utilized to control/support the grid voltage by exchanging reactive power. There are, however, some technical challenges which have been dealt with in the project:

• A small-signal model has been derived by the power electronic team in order to study the stability of a PV inverter exchanging reactive power with the grid.
• The team also proposes a method that utilizes the available capacity of the PV inverter to support the grid voltage without violating the rating of the inverter and the maximum voltage that the inverter’s switching device can withstand.