Intelligent-search technique based strategic placement of synchronized measurements for power system observability

• A new intelligent-search technique based PMU placement method is proposed.
• The zero injection buses are modeled using a simple topological transformation method.
• Incorporation of the proposed PMU placement scheme into the existing power system is also considered.
• Both single and multiple flow measurements connected to a bus can also be handled.
• Our results are more effective than the results of existing methods especially for larger systems.

Synchronized phasor measurements placement problem is commonly solved by formulating it as a mathematical optimization problem, which is limited by huge computational burden especially for larger systems. This paper proposes a novel intelligent search based approach for placement of phasor measurement units (PMUs) in the power system while maintaining complete observability. The proposed approach works in two stages. Stage I utilizes best first search to identify the possible locations of PMUs in order to obtain system observability and these locations are used as inputs to stage II. Stage II determines the optimal locations of PMUs by applying pruning to the inputs received from stage I, such that the system observability is achieved with the minimum number of PMUs. The proposed approach has been further extended to incorporate the presence of conventional flow measurements. An important feature of the proposed placement method is its capability to handle both single as well as multiple flow measurements connected to a bus. The proposed method has been tested on IEEE 14-bus, IEEE 30-bus and a practical 246-bus Indian networks for system intact condition as well as during single transmission line and single PMU loss. The effectiveness of the proposed method has been demonstrated by comparing the numerical results obtained using the proposed method with the existing methods.