What is the Phasor measurement unit?
Phasor measurement unit (PMU) is a means to ensure phase difference and amplitude of periodic sinus waves and is intended to monitor the quality of the AC power (AC) provided by electric energy companies on the electrical network. Phasor refers to the mathematical model of the vector with the direction and amplitude of electric waves in the phase measurement. When referring to the periodic nature of AC, Phasor is a specific type of vector that only has a phase relation to its reference phase. If there is only one generator in the electricity transmission, there is no need for a phasor measurement tool. However, grids have several generators that feed the same energy distribution system. For example, the frequency of usefulness of 60 cycles per second (CPS) or 60 Hertz (Hz) completes one cycling each about 0.016667 seconds. The difference of the phase between the outputs of individual generators in the system must be very close to zero. This difference in Phasor increases when one generator runs just a little faster or just a little slower than the OstAtmates generators or has an output that was eventually higher or lower than the required net level.
Two generators of 5-Kovolt-on (KVA) at 110 volts (V) and 60 Hz show the importance of phase measurements. Without synchronization, these two generators will be triggered and each will deliver 110 volts alternating current (VAC) at 60 Hz. These two half -capacity generators can provide emergency energy with two sets of lights and appliances of about 2.5 kilowatts (KW), which corresponds to about 22.8 A. This dual generator system requires no PMU because two generators are not in the same circuit.
Connecting two generators that need to be synchronized in frequency and phase, with a grid requires a unit of phasor measurement. Two generators can generate 110 VAC at exactly 60 Hz. If these generator outputs are a precisely zero stage difference, the outputs of these generators can be connected together andcreates a grid. Special hardware and software are used to ensure that generators are always synchronized. Any exception can result in a partial outage of the total grid.
Phasor measurement unit is required to automate the power system to create an intelligent grid. With the help of global positioning (GPS), precise frequencies and phase outputs of several power plants can be synchronized using PMU and control devices. Precise and accurate, control of these power plants throughout the grid together with the calculated compensation for the electrical properties of the transmission system and the demand statistics causes continuous electricity energy.