Distribution network blackouts are considered very limited. However, any major crisis in the network has high impact on consumers and distribution network operators (DNO). Overload, lack of maintenance and weather are mainly effected by network reliability and leads to cascading failures. Notably, the continuous growth in load demands and deteriorating cables increase the chances to fail the electrical system. To ensure power system availability and reliability, electrical power system should be resilient. Although, contingencies plans can manage restoration schemes to important and vital loads by finding the fault, isolate it and restore the supply neatly, but still other normal loads unable to get supply. The purposes of this thesis to keep the power supply running by enhancing microgrids (MGs) interactions between photovoltaic (PV) plants and battery energy storage systems (BESS) which is integrated to the electrical distribution network. When the main source of supply is lost, the upstream circuit breaker (CB) open and the supply restored by the MGs which located and integrated into the distribution network. Then, interactions schemes between PVs and BESSs are functioning to provide uninterrupted supply by MGs resources. The algorithm of the scheme is considering BESS and energy management to reduce the interruption impact at night for other customers. Sizes, locations, and total numbers of MGs are planned to handle peak demand and to cover unforeseen cases, such as restoring the supply of another electrical circuit network by using interconnection. When the MGs work in island mode as a standalone system, the electrical distribution system completely depends on generated power by PVs and stored power by BESS. Accordingly, the MG resources should be capable of handling the load demand any time during the interruption until the DNO clearing the fault and restore the main power supply. Electric power distribution reliability indices are employed to define the optimum locations for MGs. Accordingly, the sizes and the total number of MGs are selected based on location, voltage violation, and power losses. To ensure the electrical distribution system reliability and availability, an interaction algorithm formula is needed to manage load sharing between PVs and BESS during the interruption at daylight and night. On the otherhand, some constraints are there for charging and discharging BESS to keep the state of charge (SOC) between 20% to 90%. This research provides, an algorithm to organise all MG interactions including charging and discharging limits. The research methodology investigates and simulates the data by using DIgSILENT PowerFactory SP3 against different situations. The proposal is compared with existing restoring scheme by PVs only. Furthermore, the modification is tested again and verifies the reliability indices to compare it with the existing scheme. The resulting algorithm is implemented in different case studies for validation and testing purposes.
Date of Award | 2017 |
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Original language | English |
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- electric power systems
- load dispatching
- mathematical models
- electric power distribution
- electric power failures
- microgrids (smart power grids)
- algorithms
Decentralize operational scheme for large-scale smart microgrids integrated into utility network in island mode
Al Omar, W. F. (Author). 2017
Western Sydney University thesis: Master's thesis