Three-phase Signals Research Articles

A New Multivariable Filter with Variable-Frequency Characteristics for Three-Phase Signal Processing

A New Multivariable Filter with Variable-Frequency Characteristics for Three-Phase Signal Processing

An instantaneous peak detection method for three-phase sinusoidal signals

This paper presents a new amplitude detection method for three-phase sinusoidal signals. The proposed detection method is based on calculation of the Park transformation. This method measures the amplitude of three-phase signals instantaneously and the ideal and non-ideal conditions are analysed. An electronic circuit for implementing this method is developed and tested to demonstrate the performance of the proposed method.

A New Unified Analysis of Filters Accompanied with Vector Rotaters for Three-Phase Signal Processing

A New Unified Analysis of Filters Accompanied with Vector Rotaters for Three-Phase Signal Processing

A new peak detection method for the three-phase sinusoidal signals

An instantaneous amplitude detection method for the three-phase sinusoidal signals is proposed. The proposed method can measure the amplitude of the three-phase signals without any delay by using only two of the three-phase signals. The performance of this method under the ideal and nonideal conditions is analyzed. To demonstrate the performance of the proposed method, an electronic circuit for implementing this method is developed and tested.

An instantaneous amplitude detector for variable frequency three-phase sinusoidal signals

A fast peak detector for three-phase variable frequency sinusoidal signals is proposed. This new detector fully uses the three-phase characteristic to achieve instantaneous response, frequency and phase sequence independence characteristics. Also, the proposed detector possesses excellent linearity and low sensitivity to phase unbalance and harmonic distortion. Theoretical basis, hardware implementation, and experimental results are all detailed in this context. >

Fast peak detector for variable frequency three-phase sinusoidal signals

A fast peak detector for three-phase variable frequency sinusoidal signals is proposed. This novel detector fully uses the three-phase characteristic to achieve instantaneous response and frequency independence characteristics. Moreover, the proposed detector possesses excellent linearity and low sensitivity to small voltage unbalance and harmonic distortion. Because of its promising accuracy and transient response, it can be used to improve the transient response performance of the conventional sinusoidal peak detectors. Theoretical analysis and some experimental results are also detailed in this context.

A quick response peak detector for variable frequency three-phase sinusoidal signals

An instantaneous peak detector for three-phase variable frequency sinusoidal signals is proposed. The three-phase characteristic is fully used in the proposed detector to achieve instantaneous response and frequency independence characteristics. A very simple hardware implementation circuit is also presented for minimizing the number of analog computational components. Moreover, the proposed detector possesses excellent linearity and low sensitivity to small voltage unbalance and harmonic distortion. Because of its promising accuracy and transient response, it can be used in many systems such as the voltage regulator of an uninterruptible power supply (UPS), an automatic line voltage regulator, or electric generators, etc., to improve the system transient performance. Theoretical analysis, hardware implementation, and some experimental results are also detailed in this paper. >

A new numeric technique for high-speed evaluation of power system frequency

A new numerical technique for evaluating power system frequency from either a voltage or current signal is presented. The technique uses discrete time values of the input signal, taken at a fixed sampling rate, to provide an estimate of power system frequency accurate to within typically 0.001 Hz. The technique is shown to be capable of tracking frequency under dynamic power systems conditions and is immune to the effect of harmonics. It is further shown that the algorithm can be easily adapted to process three-phase signals such that the positive phase sequence component can be utilised thus increasing the reliability of the measurement under fault conditions.

Three-phase signal generation from a single-phase reference signal

The authors consider the conversion of a single-phase reference signal into three-phase signals using a switched-capacitor frequency-independent phase-shifting network. This circuit provides a constant phase-shift of 120 degrees and 240 degrees between 40 and 75 Hz. The phase-shift can be changed by changing the divide-by-N factor or the capacitor values.

Optical homodyne phase metrology

Electronic circuitry that is helpful for measuring optical phase from three-phase input signals is described. Six flash analog-to-digital converters in conjunction with a read-only memory resolve a digital byte (or more) per turn of phase. That digital phase may then be digitally low pass filtered with an adder and multiplier accumulator to expand the dynamic range by counting turns and shrinking the subdivisions.

A suggested methodology for data acquisition, measurement and control using microcomputer and multiprocessor systems

Abstract This paper proposes three-phase measurement systems which can be built around a microcomputer and further upgraded using multiprocessors. These systems will have the ability to measure the instantaneous values of three-phase voltages and currents and to use these values to calculate active power, reactive power, RMS and peak values of voltage and current, and to display these values using graphic capabilities. These systems can also be used to measure DC voltages and currents and calculate DC power. The maximum frequencies of the three-phase signals that can be measured depend on the sampling rate of the system, which depends on different factors such as the frequency of operation of the microcomputer and of its various peripherals. An attempt will be made to relate these different factors to the sampling rate of the system. The maximum resolution of measurements that can be made by this system depends on the analog/digital (A/D) converter that is used. A maximum resolution of 0.0015% can be achieved by using a 16-bit A/D converter.

Computerized angular position transducer

A computerized angular position transducer has been developed for introductory laboratory use. The transducer employs a three-phase synchro controller for precisely determining angular position. The computer supplies a precise three-phase signal and also provides processing capability. Data are collected at the three-phase frequency at high resolution. The device appears to be a very useful transducer for physics laboratory experiments involving rotational or vibrational motion.

A NOVEL THREE-PHASE SINUSOIDAL PULSE-WIDTH MODULATION WAVEFORM GENERATOR

Abstract Pulse Width Modulation is widely used in static power inverters (d.c. to a.c. converters) to control the output voltage and the harmonic content in it. Sinusoidal pulse width modulation is known to produce the least harmonic content in the inverter output. This paper describes a novel control circuitry that generates the three-phase sinusoidal pulse width modulation signals using a single phase sinusoidal reference signal and a triangular carrier signal. The advantages of this circuit are discussed and experimental results are presented

A New Two-Three-Phase Voltage-Controlled Oscillator

The initial aim of the work has been the development of an inexpensive quadrature oscillator which can operate as a rapidly responding voltage-controlled oscillator (VCO) in two phases. Such rapid operation in quadrature is needed in association with quickly operating phase-locked loops for frequency synthesizers and similar applications. Other applications, where the relatively large speed is not essential, but where the phase shifts between various outputs should be precise, are mentioned in concluding this section. The electronic realization is made relatively cheap by proposing a replacement of the instantaneous amplitude measuring operation of square and sum (x <R xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</R> + y <R xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</R> ) (associated in the process of amplitude stabilization) by an operation of three-phase rectification. This leads to the construction of a versatile instrument which generates three-phase signals as well as two-phase signals (the two-phase signals are both sinewaves in quadrature and also square waves in quadrature). All these waveforms are capable of participating in the system performance as a VCO at a relatively large rate of frequency changes. A reversal in the order of phases when the frequency-control voltage crosses zero is also exhibited. This is needed in applications in industrial and power electronics. Our main aim now is to use the instrument in association with a precisely stabilized quickly responding cyclo-converter. Other possible applications of the instrument are in the field of precise measurements (for example, in the detection of signals by lock-in amplification there exists a frequent need for quadrature operation) and in telecommunication.

Low cost digital I.C.'s yield three-phase signal generator : R. P. Bisey. Microelectronics3, No. 9 (1970), p. 19

Low cost digital I.C.'s yield three-phase signal generator : R. P. Bisey. Microelectronics3, No. 9 (1970), p. 19