摘要:
A communication system for a power line is described. A transmission system of the communication system divides the time axis into a number of time slots synchronized such that one time slot can start about a zero crossing of the power line signal. These time slots are referred to as channels and are numbered from 1 to n. A modulation method is described to is narrow band continuous phase FSK, where a number m of modulating frequencies are used, arranged such that an integral number of full cycles fit into each channel time slot for all m frequencies. The system transmits during only a subset of the available time slots (channels) concentrated near the zero crossing of the power line waveform where the noise is typically minimal.
摘要:
Pendant une première phase d'essai (I), le dispositif permet, après avoir détecté la présence d'une charge (t2 - t3) d'identifier la nature de la charge. Pour cela, un circuit de contrôle connecte la charge à un réseau d'alimentation alternatif, tout en limitant le courant dans la charge. Il mesure plusieurs dizaines de valeurs instantanées de la tension et du courant de charge pendant un nombre limité d'alternances et détermine l'impédance de charge ainsi que le déphasage courant/tension. Ces caractéristiques permettent, éventuellement avec des paramètres complémentaires dérivés des mesures de tension et de courant, d'identifier la nature de la charge. Pendant une seconde phase d'essai (II), le circuit de contrôle applique à la charge des impulsions limitées en tension et détecte d'éventuels défauts de court-circuit, différentiel ou de surcharge.
摘要:
A method of and system for processing a digital signal are disclosed. Disclosed also are an electric power system digital controlling system and a digital relay system which utilize the signal processing system for obtaining physical quantities of a voltage and a current inputted from the electric power system. An analog signal is sample-held. The sample-held data is converted into digital data which is then filtering-processed. Arithmetic processing is effected based on the data from a digital filter means. In this digital filter means, a blocking zone of the digital filter is set to a higher frequency zone than a passage zone of the analog signal. A sampling frequency is set so that a noise generating region is larger than the blocking zone. The synthesis noises are thereby caused in the blocking zone.
摘要:
Der Sender erzeugt ein für die zu sendenden Daten repräsentatives Stromsignal als Laststrom einer speziellen Last, Zum Senden dieses Stromsignals wird die Last kurzzeitig mit einer Spannungsquelle verbunden, wodurch eine Reihe von Stromimpulsen (I) erzeugt wird. Die Zeitpunkte der Erzeugung und/oder die Dauer dieser Stromimpulse werden so gewählt, dass das resultierende Sendesignal wenigstens angenähert einem gewünschten theoretischen Signal (R) entspricht. Das Verfahren weist bezüglich der Frequenz des Stromsignals eine hohe Flexibilität auf, und der Sender erfordert weder Verstärker, noch abgestimmte, die Sendefrequenz mitbestimmende Resonanzkreise. Das Verfahren eignet sich insbesondere für die Rückmeldung von Daten über beispielsweise den Zählwerkstand von über das Netz verteilten Zählern oder über die erfolgte Befehlsausführung von Rundsteuerempfängern an eine Zentrale.
摘要:
Apparatuses (10) comprise first circuits (1) for detecting problems in or near loads (111) powered via a cable (101) of a cable system and second circuits (2) for in response to detection results from the first circuits (1) changing a characteristic frequency of the cable system. The first circuits (1) may comprise detectors for detecting currents, voltages and impedances and the second circuits (2) may comprise signaling capacitors (21) and switches (22). Devices (30) for searching for problems in the cable system comprise third circuits (3) for measuring values of the characteristic frequency and fourth circuits (4) for comparing the measured values of the characteristic frequency with reference values. The devices (30) may comprise fifth circuits (5) for deriving from the measured values and from information about the apparatus (10) values of inductances of the cable system and sixth circuits (6) for converting the derived values into locations of the problems or into distances defining locations of the problems.
摘要:
A communication system for a power line is described. A transmission system of the communication system divides the time axis into a number of time slots synchronized such that one time slot can start about a zero crossing of the power line signal. These time slots are referred to as channels and are numbered from 1 to n. A modulation method is described to is narrow band continuous phase FSK, where a number m of modulating frequencies are used, arranged such that an integral number of full cycles fit into each channel time slot for all m frequencies. The system transmits during only a subset of the available time slots (channels) concentrated near the zero crossing of the power line waveform where the noise is typically minimal.
摘要:
A data telemetering system includes a plurality of remote transmitter units (RTU₁-RTU n ) connected via an alternating current power supply mains (PSM) to a central receiver (CRU). Each cycle of the line voltage is divided into a plurality of time slots, and each transmitter (RTU₁-RTU n ) transmits its data in a separate time slot assigned to it. The data is binary multi-bit digital data, and one bit is transmitted by each transmitter (RTU₁-RTU n ) in its assigned time slot during each cycle of the line voltage.
摘要:
A momentary decrease of the line voltage level, is used to control a momentary decrease of the level of supply loads, is that the level of average electric power applied to dissipative loads (6) by an electric energy distribution network is reduced. The supply voltage decrease is detected at the various loads (6) and the average electric power originating from the distribution network and transmitted to the loads, is reduced following such a detection. This momentary decrease can also be used for controlling the scale of charges of the electricity meter of a residence. Thus, average power consumed by the loads (6) supplied by the distribution network can be easily controlled by the electricity production company.