A Pover Angle and Rotor Speed Measurement Device for Synchronous Machines Stability Studies

Abstract

A device for measurement of power angle and rotor speed of a synchronous generator has bi-en designed and realized. The device is supplying a signal proportional to the phase angle between the terminal voltage and generated e.m.f. phases of the synchronous machine. A second signal proportional to the rotor speed is also generated. These output signals can be used for both measurement and control purposes. The device under consideration can also be used in conjunction with digital systems through an analog to digital converter (A/D) to perform on-line computation and control. The design and realization of the device depend on high speed digital and linear integrated circuits. The time delays introduced by the device components are negligible compared to the machine time constant , therefore the device is most suitable for applications in both transient and dynamic conditions in synchronous machines. The device is capable of monitoring the variations in the power angle and the rotor speed for both measuring and control purposes. Further, this device can be used as a part of a digital control system to provide stabilizing signals to digital automatic voltage regulator of synchronous machines. The test and calibration results obtained show the capability of the device to monitor the power angle and rotor speed in both steady state and transient conditions .

A Performance Measurement Device for Synchronous Machines Stability

“…The DC output voltage is obtained from pin 4 (emitter follower of the output transistor). The DC output voltage obtained (V odc ) is given by [7]: The emitter output (pin 4) is connected to the inverting input of the operational amplifier (pin 7), so that the voltage of pin 4 will follow the voltage of pin 3 , therefore the output impedance will be decrease and the voltage obtained will be proportional to the input frequency.…”

“…Also, this research presents a rotor speed-measuring device, which counts the reflected pulses from the rotor axis and converts this count to DC voltage level proportional to the rotor speed. The tests and calibration results show that the device is accurate and simple and it can be used for both measuring and control purposes [6,7].…”

Design and Implementation of a Power System Phasor Measurement Unit

“…This device provides a dc output voltage level proportional to the input frequency and equal to the exact value of the rotor speed ( ), it gives a zero output voltage at zero input frequency. The circuit diagram for the rotor speed is shown in figure (5). The integrated circuit used in this device contains an input amplifier with built-in hysteresis, a charge pump frequency to voltage converter, and an operational amplifier with an output transistor.…”

“…Referring to the circuit diagram of the power angle transducer seen in figure (5), the differentiated rotor pulses in the non-inverting input of OA1 are shown in figure (8). Also the output pulses obtained from zero crossing detecting circuit of the bus bar voltage (output of COMP1) are shown in figure (9).…”

“…Also, this paper presents a rotor speed-measuring device, which counts the reflected pulses from the rotor axis and converts this count to DC voltage level proportional to the rotor speed. The tests and calibration results show that the device is accurate and simple and it can be used for both measuring and control purposes [5]. As a new trend, phasor measuring units (PMUs) using synchronization signals from the GPS (Global Positioning System) satellite system has evolved into mature tools and is now being manufactured commercially.…”