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Phase detector

About: Phase detector is a(n) research topic. Over the lifetime, 16429 publication(s) have been published within this topic receiving 132405 citation(s).

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Papers
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Journal ArticleDOI: 10.1109/TPEL.2006.890000
Pedro Rodriguez, Josep Pou1, J. Bergas1, Jose Ignacio Candela1  +2 moreInstitutions (2)
Abstract: This paper deals with a crucial aspect in the control of grid-connected power converters, i.e., the detection of the fundamental-frequency positive-sequence component of the utility voltage under unbalanced and distorted conditions. Specifically, it proposes a positive-sequence detector based on a new decoupled double synchronous reference frame phase-locked loop (DDSRF-PLL), which completely eliminates the detection errors of conventional synchronous reference frame PLL's (SRF-PLL). This is achieved by transforming both positive- and negative-sequence components of the utility voltage into the double SRF, from which a decoupling network is developed in order to cleanly extract and separate the positive- and negative-sequence components. The resultant DDSRF-PLL conducts then to a fast, precise, and robust positive-sequence voltage detection even under unbalanced and distorted grid conditions. The paper presents a detailed description and derivation of the proposed detection method, together with an extensive evaluation using simulation and experimental results from a digital signal processor-based laboratory prototype in order to verify and validate the excellent performance achieved by the DDSRF-PLL

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Topics: Reference frame (53%), Phase detector (51%), Robust control (51%) ...read more

1,039 Citations


Patent
01 Aug 1986-
Abstract: An ultrasonic apparatus for testing a material comprises an oscillator (10) which generates a selected frequency in the ultrasonic range. A transducer (1) is connected to the oscillator (10) for applying an ultrasonic signal to the material and for receiving an echo signal back from the material. A phase detector (5) receives the echo signal and an in-phase oscillator signal to generate a first display signal, and a phase detector (6) receives a quadrature signal (90° out of phase from the oscillator signal) and the echo signal to generate a second display signal. The first and second display signals are utilised in a visual display, such as a cathode ray tube (8), to generate an image. The image changes according to the phase shift between the ultrasonic signal transmitted into the material and the echo signal, which, in turn, can be utilised to determine the presence and depth of a flaw or boundary in the material.

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Topics: Signal (63%), Analog signal (61%), Signal transfer function (59%) ...read more

1,017 Citations


Proceedings ArticleDOI: 10.1109/PESC.2006.1711988
18 Jun 2006-
Abstract: Phase, amplitude and frequency of the utility voltage are critical information for the operation of the grid-connected inverter systems. In such applications, an accurate and fast detection of the phase angle, amplotude and frequency of the utility voltage is essential to assure the correct generation of the reference signals and to cope with the new upcoming standards. This paper presents a new phase-locked-loop (PLL) method for single-phase systems. The novelty consists in generating the orthogonal voltage system using a structure based on second order generalized integrator (SOGI). The proposed structure has the following advantages: — it has a simple implementation; — the generated orthogonal system is filtered without delay by the same structure due to its resonance at the fundamental frequency, — the proposed structure is not affected by the frequency changes. The solutions for the discrete implementation of the new proposed structure are also presented. Experimental results validate the effectiveness of the proposed method.

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Topics: Linear phase (58%), Phase frequency detector (55%), Integrator (55%) ...read more

914 Citations


Patent
Abstract: Apparatus monitors RF return current to maximize the AC signal of impedance at two return electrodes. A transformer with driving and driven windings isolates ESU and patient. At ends of the driving winding are signal and ground terminals joined to the return electrodes with capacitors returning current. An AC coupling capacitor at the signal terminal has a timing circuit in sync to the voltage wave and relative to impedance of the return electrodes. Microprocessing the voltage at the signal terminal of the driving winding watches impedance and determines if the RF return current path is adequate. Voltage detection within the timing circuit has a voltage shaping circuit. A voltage comparator after the voltage detection forms a square wave. A current detection circuit and a coupling capacitor allow AC flow to the driving winding. Current shaping circuit in the current detection circuit has a voltage comparator at the output to form a square wave. Phase detection at the voltage and current detection circuits outputs filters the phase difference that is sampled and held as DC input to a switch, with an output and a few inputs to DC voltages. Phase locking an oscillating voltage source directly and/or through the sample and hold or DC switch tunes oscillation frequency and maximizes the voltage detection circuit output. Monitoring the return current with a signal from the voltage detection circuit connected to an oscillating voltage that is phase locked to the current phase therein shows that no phase difference and maximum signal voltage occur simultaneously.

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Topics: Voltage source (67%), Electrical impedance (59%), Voltage (57%) ...read more

783 Citations


Journal ArticleDOI: 10.1364/OL.15.001351
James P. Gordon1, Linn F. Mollenauer1Institutions (1)
01 Dec 1990-Optics Letters
Abstract: Spontaneous emission noise limits the capacity and range of photonic communications systems that use linear optical amplifiers. We consider here the question of phase detection in such systems. Amplitude-to-phase-noise conversion occurs owing to the nonlinear Kerr effect in the transmission fiber, resulting in optimal phase noise performance when the nonlinear phase shift of the system is approximately 1 rad. Error-free state-of-the-art systems that use phase detection at multigigabit rates are thereby limited to a range of a few thousand kilometers.

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Topics: Phase noise (61%), Noise (electronics) (58%), Photonics (56%) ...read more

668 Citations


Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20221
2021153
2020265
2019275
2018277
2017320

Top Attributes

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Topic's top 5 most impactful authors

Dikarev Viktor Ivanovich

33 papers, 50 citations

Xiaoping Liao

20 papers, 70 citations

Deog-Kyoon Jeong

19 papers, 566 citations

Shen-Iuan Liu

19 papers, 366 citations

Behzad Razavi

17 papers, 803 citations

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