Graph Search Based Management of Distributed Energy Resources and Coordinated Voltage Control

As the energy demand rises around the world, the concerns regarding the impact of fossil fuel on the environment become more and more evident. To introduce a cleaner and more sustainable energy solution, the world moving towards integrating more and more renewable energy into the grid. A significant amount of renewable generation are being integrated into the grid, and are known as the distributed energy resources (DERs). Due to the increasing integration of DERs, the notion that power is generated in bulk at a generation plant and then transmitted through the transmission and distribution system to the consumers is no longer true. Distributed generation has made it possible to generate power near the demand location. This has also introduced fast changing distributed generation (DG) and reverse power-flow in the system. Researchers are currently working on finding out proper ways to optimally integrate the DERs and tackle the issues resulting from them. This dissertation is focused on tackling two such topics emerging from the integration of DERs. The first topic is the topic of optimally using the available energy resources to minimize the cost. With the addition of variable non-dispatchable generations, there has also been a rise in energy storage (ES) integration into the grid. There can also be traditional generation like diesel generators available as DG. Due to smart grid technologies, we also have the availability of present grid data and different forecasts regarding future grid states.How to optimally control all these available energy resources based on the present and forecasted data available is still a topic of research. This dissertation proposes a novel graph search based energy management solution that can optimally manage the energy resources based on current and predicted system status. The energy management solution has been validated using a real-time controller hardware in the loop (CHIL) solution. The validation process shows that the proposed solution is capable of cost optimally managing the available energy resources. The second topic tackled in this dissertation is the topic of maintaining the distribution system voltage within limits. As the penetration of variable non-dispatchable DGs increase in the system, there is a higher chance of voltage violation. This can also cause the traditional mechanical regulation devices to work more. This can cause wear and tear in the mechanical devices used for regulation, and may introduce an additional operating cost. Also, the theory that the voltage across the line is only dependent on the load and the line impedance is not accurate anymore. Sudden changes in the variable DGs output can introduce over and under voltage in specific portions of the distribution system near them. There are also smart inverters available in the system with the capability of providing reactive power compensation. This dissertation provides a novel solution to coordinate the smart inverters with the traditional regulation devices to regulate the system voltage. The proposed solution has been validated both in offline simulation and in real-time CHIL simulation. In summary, this dissertation proposes two novel solutions. The first is an energy management solution capable of managing DERs taking into account present and forecasted system status and system constraints. The second is a coordinated voltage control algorithm capable of optimally coordinating the smart inverters with traditional regulation devices. Both of the proposed solutions have been validated in offline and CHIL simulations and are shown to work as expected.