摘要:
A meter apparatus (100) is proposed for determining parameters of an AC electric signal in first (L) and second (N) wires, the AC electric signal comprising an AC electric current ( I AC ) and an AC electric voltage ( V AC ). The meter apparatus (100) comprises: a measurement section (115) configured for providing first ( V VS1 ) and second ( V VS2 ) measure signals each one indicative of the AC electric voltage ( V AC ) based on a first capacitive coupling (C 1 ) with the first wire (L) and on a second capacitive coupling (C 2 ) with the second wire (N), the first ( V VS1 ) and second ( V VS2 ) measure signals depending on capacitance values of the first (C 1 ) and second (C 2 ) capacitive couplings, and a control unit (120) configured for: determining said capacitance values of the first (C 1 ) and second (C 2 ) capacitive couplings according to the first ( V VS1 ) and second ( V VS2 ) measure signals, and determining the amplitude of the AC electric voltage ( V AC ) according to the first ( V VS1 ) or second ( V VS2 ) measure signal, and to the capacitance values of the first (C 1 ) and second (C 2 ) capacitive couplings.
摘要:
L'invention concerne un circuit de surveillance d'un réseau électrique triphasé comprenant trois phases (φ Α , Φ Β , Φ C ) ayant chacune une tension alternative, le circuit étant connecté aux trois phases (φ Α , Φ Β , Φ C ) de manière à prélever une tension image du réseau correspondant à une combinaison des tensions alternatives, ledit circuit étant configuré pour, à partir de la tension image pouvant prendre plusieurs formes d'ondes, détecter qu'au moins une phase est absente, les formes d'ondes de la tension image lorsque les trois phases sont présentes étant différentes des cas où au moins une phase est absente.
摘要:
Determination of electrical network topology and connectivity are described herein. A zero-crossing is indicated at a time when the line voltage of a conducting wire in an electrical grid is zero. Such zero-crossings may be used to measure time within a smart grid, and to determine the connectivity of, and the electrical phase used by, particular network elements. A first meter may receive a phase angle determination (PAD) message, including zero-crossing information, sent from a second meter, hereafter called a reference meter. The first meter may compare the received zero-crossing information to its own zero-crossing information. A phase difference may be determined between the first meter and the reference meter from which the PAD message originated. The first meter may pass the PAD message to additional meters, which propagate the message through the network. Accordingly, an electrical phase used by meters within the network may be determined.
摘要:
A system and method for estimating the magnitude and phase of magnetic and electrical currents in a power line comprising at least one processor operating to create a model of the power line and derive expected complex magnetic and electric-field values; at least one memory; at least one sensor positioned proximate to the at least one power line for sensing and providing measurements of the magnetic and electric fields of the at least one power line; the at least one processor operating to compute a set of complex magnetic and electric field values based upon the measurements provided by the at least one sensor and to estimate parameters related to the complex voltage and/or current of the at least one power line based upon the measured field values and the set of expected complex electric current and voltage values derived from a model of at least one power line.
摘要:
A clock phase shift detector circuit 100 may include a phase detector 102 for generating a phase signal (Z) based on a phase difference between first (I) and second (Q) clock signals. A current mirror 104 having a first (C 1 , a second (C 2 ), and a third (C 3 ) integrator may be coupled to the phase detector 102, whereby the first integrator integrates the first clock signal and generates a first voltage, the second integrator integrates the first clock signal and generates a second voltage, and the third integrator integrates the phase signal and generates a third voltage. A first comparator 106 receives the first and the third voltage, and generates a first control signal. A second comparator 108 receives the second and the third voltage, and generates a second control signal. The first and second control signals may detect a change between the phase difference of the first and the second clock signal and an optimized phase difference.
摘要:
In one aspect, a method for protecting one or more electrical machines during an islanding event is provided. The method includes connecting one or more electrical machines to an alternating current (AC) electric power system, wherein the AC electric power system is configured to transmit at least one phase of electrical power to the one or more electrical machines or to receive at least on phase of electrical power from the one or more electrical machines; electrically coupling at least a portion of a control system to at least a portion of the AC electric power system; coupling at least a portion of the control system in electronic data communication with at least a portion of the one or more electrical machines; and detecting an islanding of the one or more electrical machines based on one or more conditions monitored by the control system.
摘要:
The invention relates to a generic method for determining the rotor position of an electronically-commuted multi-phase direct current motor, characterised in: (a) generation of a plurality of test voltage pulses in the winding system with a specified switch-on duration DeltaTau by means of the commuting device in different phases distributed over 360°; (b) measurement of the current values of the current responses of the test voltage pulse on expiration of the switch-on period of the respective test voltage pulse; (c) approximation of the measured current values by means of a periodic approximation function from a superimposition of a preferably sinusoidal fundamental wave with an amplitude IEMK and the associated first harmonic with an amplitude Und as a factor of the phase of the test voltage pulse, wherein the sinusoidal fundamental wave follows the chronological progression of the counter EMF voltage of the stator and the first harmonic follows the chronological progression of the stator of the direct current motor; (d) determination of an amplitude ratio value IEMF/IInd of the fundamental wave and the first harmonic of the approximation function; (e) determination of the rotor position as the EMF angle from the argument of the first harmonic of the approximation function as a factor of the amplitude ratio IEMF/IInd, wherein the EMF angle indicates the phase offset of the sinusoidal progression of the counter EMF voltage of the stator relative to the approximation function and the inductivity angle indicates the phase offset of the sinusoidal progression of the inductivity of the stator relative to the approximation function.
摘要:
Das Verfahren umfasst die Schritte: - Betreiben der Synchronmaschine (4) im Leerlaufbetrieb, - Erfassen eines Phasenspannungs-Messwertes (206) der Synchronmaschine (2), - Ermitteln eines Phasenspannungs-Erwartungswertes (208) durch Zuordnen von abgespeicherten Kennfeldwerten (210) für die Phasenspannung, für den Erregerstrom und die erfasste Drehzahl der Synchronmaschine (2), und - Vergleichen des Phasenspannungs-Erwartungswertes (208) mit dem Phasenspannungs-Messwert (206). Ferner gehört zur Erfindung eine Diagnosevorrichtung zur Durchführung dieses Verfahrens sowie ein entsprechendes Computerprogrammprodukt.