43 Priyanka Modi, Sangeeta Kamboj International Journal of Electronics, Electrical and Computational System IJEECS ISSN 2348-117X Volume 4, Special Issue March 2015 Implementation of DSP Techniques for Phasor estimation in Phasor Measurement Unit (PMU) Priyanka Modi, Sangeeta Kamboj Department of Electronic Instrumentation and Control Engineering Thapar University Abstract Phasor measurement unit (PMU) is a new technology which is still evolving. In the paper, the designing of PMU is discussed. The DSP techniques such as zero crossing and Discrete Fourier Transform (DFT) have been used for estimation of Voltage Phasor in PMU. The paper also discussed recursive and non recursive DFT technique for phasor estimation. 1.Introduction Recent blackouts throughout the world have affected reliability of power supply in electrical grids. PMU is an emerging technology for modern power systems (smart grid). Nowadays, most of the substations are equipped with PMUs which can collect huge amounts of data in addition to performing their intended functions. PMU is a device which measures the instantaneous frequency, current and voltage on an electricity grid to determine the health of the system. PMU adds a precise time stamp to the phasor values determined by it. GPS reference source provides needed synchronous sampling [1]. PMU assembles a message from the time stamp and the phasor data in a format defined in IEEE standard C37.118.1-2011 which can then be transmitted to a remote site over any available communication link [1-2]. Global reference time helps in wide area monitoring of power system. Synchrophasor technology provides the real-time wide-area grid visibility such as oscillation detection, frequency and voltage monitoring which avoids blackout conditions [1]. In the paper, DSP techniques such as zero crossing and DFT (recursive/non-recursive) are used to compute phasor of a voltage signal 2. Phasor measurement unit A) Phasor Phasor is a quantity with magnitude and phase (with respect to a reference) that is used to represent a sinusoidal signal [2]. Fig.1 Phasor representation of a sinusoidal quantity