Development of cost-effective phasor measurement unit for wide area monitoring system applications

<span>Sustained growth in the demand with unprecedented investments in the transmission infrastructure resulted in narrow operational margins for power system operators across the globe. As a result, power networks are operating near to stability limits. This has demanded the electrical utilities to explore new avenues for control and protection of wide area systems. Present supervisory control and data acquisition/energy management systems (SCADA/EMS) can only facilitate steady state model of the network, whereas synchrophasor measurements with GPS time stamp from wide area can provide dynamic view of power grid that enables supervision, and protection of power network and allow the operator to take necessary control/remedial measures in the new regime of grid operations. Construction of phasor measurement unit (PMU) that provide synchrophasors for the assessment of system state is widely accepted as an essential component for the successful execution of wide area monitoring system (WAMS) applications. Commercial PMUs comes with many constraints such as cost, proprietary hardware designs and software. All these constraints have limited the deployment of PMUs at high voltage transmission systems alone. This paper addresses the issues by developing a cost-effective PMU with open-source hardware, which can be easily modified as per the requirements of the applications. The proposed device is tested with IEEE standards.</span>

A Robust Algorithm for Real-Time Phasor and Frequency Estimation under Diverse System Conditions

This paper presents a comprehensive approach for performing phasor and frequency estimation from voltage and/or current signals of the modern power system. Undesirable components, such as decaying DC, if present in the input signal, are first attenuated using a complex-gain filter. The initial estimates of phasor and frequency are obtained next using the discrete Fourier transform and an improved estimation of signal parameters via rotational invariance technique, respectively. Finally, the accuracy of phasor and frequency estimates are increased based on the identified system condition. Simulations performed to evaluate the proposed approach confirm that it can do fast and accurate estimation of phasor and frequency under diverse operating conditions, making it ideal for wide-area monitoring, protection, and control applications in power systems.

Optimal placement of wide area monitoring system components in active distribution networks

The optimal placement of micro-Phasor Measurement Units (µPMUs) reduce the cost of wide area monitoring system (WAMS) in active distribution networks (ADNs); therefore, it is becoming a popular research topic. However, µPMUs alone cannot minimize the WAMS cost. An appropriate location of Phasor Data Concentrator (PDC) and a fiber optic communication link (CL) that transfers data from µPMUs to PDCs also need to be optimized. Hence this paper proposes a hybrid algorithm that determines the optimal cost-effective solution of the placement problem of µPMUs, PDC, and CL. The proposed algorithm uses the graph theory and binary integer linear programming (BILP) with the constraints of distribution generation (DG) presence, regular network reconfiguration, and maximizing system redundancy. The proposed algorithm is tested on IEEE 69 bus, IEEE 123 bus, and 345 bus active distribution system. The results obtained show the reduction in cost mainly through the CL and optimal placement of µPMUs in decentralized WAMS.