Grid Integration of Renewables

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Increased awareness for environmental preservation and a global desire to reduce green house gas (GHG) emissions has resulted in a higher utilization of renewable energy (RE) in the electrical grid. Consequently, the electrical grid is changing from fossil-fuel based generators to smaller locally-embedded RE generators closer to the consumer. Deregulation has also caused increased competition and improved efficiency and conservation. Furthermore, with the convergence of different technologies (such as power systems, power electronics, information technology, communication and sensors), the grid can now be transformed into a truly smart grid (SG) capable of operating in a highly coordinated manner through intelligent management systems to realize its full potential. My multi-disciplinary research program concentrates on system studies to demonstrate/promote the opportunities/weaknesses in the SG implementation and integration of RE sources. The problems to be studied relate to: 1. Two-way power flow in the feeders impacts grid components which are subjected to frequent energizing/de-energizing cycles. This leads to reduced equipment life-span due to resulting power quality issues. Furthermore, two-way power flow stresses legacy protection equipment in a way that they were never designed for. New protection systems are needed to provide reliable, safe and secure performance from the grid. 2. New SG components (i.e. fault current limiters, transfer switches, sensors, protection and synchronizing equipment) are needed to coordinate the grid integration of both legacy and modern equipment. Communication equipment, together with sensors and signal processing, will play a crucial role in the future operation of the SG. 3. RE integration issues need multi-level converters (with their advanced controllers) to feed in power from intermittent variable-voltage, variable-frequency sources into a grid that is operating at a fixed-voltage and fixed-frequency. Conservation and Demand Management (CDM) will be taking advantage of storage components and Time-of-Use controllers. Furthermore, lack of inertia from RE sources will affect the dynamic performance of the SG. Although transformation towards the SG has already begun, its full implementation may take decades before reaching its desired level of operational flexibility, security and efficiency. This research will be useful for power utilities, consultants and equipment manufacturers. It will benefit power system planners, operators and commissioning members. This research will provide opportunities for HQP training and encourage collaboration with utilities, consultants and manufacturers. The intellectual property generated will provide deeper insight into SG behavior and operation and guide the future investments in infrastructure for the renewal of aging legacy-grid components.