Hybrid AC and DC power distribution

Interest in the use of DC for medium and low voltage distribution circuits is growing as a means of reducing the multiple power conversion stages associated with connecting renewable energy sources and DC powered consumer electronic devices to the existing AC system. The possibility of carrying AC power and injected DC power at the distribution transformer in the same distribution line and filtering out them separately to AC and DC loads were investigated. Both simulations and laboratory experiments were used to prove this concept of hybrid distribution. A comparative study was carried out to show that the proposed hybrid solution minimises the energy losses in power conversion stages when integrating renewables

Dynamic voltage control of a smart distribution transformer

With the increased penetration of distributed generation, maintaining voltages across distribution networks within statutory limits becomes challenging. To maintain the voltage within statutory limits with the variability of the distributed generation, a dynamic voltage control (DVC) mechanism should be implemented. Such voltage control also facilitates load control especially at peak load periods as the demand depends on the load busbar voltages to some extent. An electronically controlled series compensator based on smart distribution transformer was investigated to achieve the DVC in the low voltage distribution system. The controller design and the operation of the three-phase series compensator and its control are discussed. The proposed topology and control strategies are evaluated on a typical distribution network. From simulations, it was found that the smart distribution transformer can be controlled with less than two cycle response to obtain performance similar to a conventional transformer. Further, the DVC enhances the loadability of the smart distribution transformer

Design and implementation of a novel controller for autonomous 2.5 kW wind power plant

Increase of electricity demand force the electrical engineers to come up with new solutions. Renewable energy sources, which needs lesser maintenance cost and with lesser environmental effects are gathering momentum. Wind power, major renewable energy source has great potential through out the world. Developing country as Sri Lanka is very much interested in wind power generation and putting effort to implement even for lower capacity. A new control was designed and implemented on 2.5 kW wind power plant is presented in this paper. The system was simulated and the results are validated with the laboratory setup before field implementation takes plac