摘要:
Des signaux d'arrivée (1s) transportés sur un réseau de distribution électrique (T3, T5, 13) sont détectés par un procédé qui consiste à extraire des données de courant électrique (d1-D8) d'une forme d'onde de ce réseau, et à soumettre ces données à un filtrage numérique de façon à produire une forme d'onde numérique. Afin d'extraire les données de signaux contenues dans les données de courant électrique, une forme d'onde de référence est produite à partir d'une partie de la forme d'onde numérique, et les données de signaux sont détectées par la comparaison de certaines parties de la forme d'onde numérique avec les parties correspondantes de la forme d'onde de référence.
摘要:
Système de communication dans lequel des informations destinées à l'extérieur sous forme de messages à bits multiples sont portées par des ondes cycliques (11) sur un réseau de distribution de puissance électrique. Le signal est détecté indépendamment en l'un quelconque d'une pluralité d'endroits éloignés de la source. La détection du signal consiste à obtenir des données de signal par l'échantillonnage des ondes cycliques sur une partie prédéterminée de cycles successifs. Ladite partie prédéterminée est divisée en une pluralité de plages prédéterminées. A partir d'un nombre prédéterminé de bits au début de chaque message, la plage particulière prédéterminée qui contient la plus forte intensité de signaux est choisie. Pour les bits restants du message, seuls les échantillons se trouvant dans la plage choisie sont analysés pour détecter le message destiné à l'extérieur. Pour éviter la diaphonie, des plages sélectionnées dans lesquelles des signaux de diaphonie sont susceptibles d'apparaître sont surveillées et des messages en phase sont rejetés lorsque l'intensité de signal dans la plage en phase est inférieure à l'intensité de signal dans au moins une des plages de diaphonie.
摘要:
A method of providing a graphic display (SD) of an electrical distribution network (N) to provide network personnel insight as to network operation comprising. A segment of the network is monitored to obtain information about predetermined types of incidents which occur. The information is then processed to ascertain where the incidents occurred and the number of incidents which occur over a predetermined period of time. The results are presented in a graphical display which includes the number of incidents occurring at each location within the network segment, and the number of incidents which occurred at each location during previous period of time at the respective locations.
摘要:
A method for concurrently communicating over each phase of an electrical power distribution network (N). A first outbound signal (SO1) is transmitted over one phase (AN-A) of a bus (S) by an outbound modulation unit. The unit is released as soon as the first outbound signal (SO1) is transmitted so the unit can transmit a second outbound signal (SO2) over a second phase (BN-B or CN-C) of the bus. The second outbound signal is transmitted concurrently with an inbound signal (IB1) sent in response to the first outbound signal (SO1). The unit is again released, as soon as the second outbound signal (SO2) is transmitted, so the unit can transmit a third outbound signal (SO3) over the third phase (BN-B or CN-C) of the bus. This third outbound signal is transmitted concurrently with a second inbound signal (IB2) sent in response to the second outbound signal (SO2). The method allows concurrent communications over all three phases of the network (N).
摘要:
A gasketless enclosure (10), for housing outdoor electrical equipment, includes a box (12) having a base (14) and upwardly extending sidewalls (16A-16D). The walls define an open top over which fits a cover (18). A closure mechanism (28) includes an upwardly projecting lip (30) formed at the top of the sidewalls and extending around the box, and a channel (32) formed in the abutting face (34) of the cover and sized to receive the lip. To help keep out moisture, gutters (42, 44) are formed in the abutting surfaces of the box and the cover. The gutter (44) is formed outwardly of the lip, and the gutter (42) is formed outwardly of the channel. The gutter (42) is above the gutter (44) when the cover is in place. The gutter formed along the top and sides of the box is open at the bottom of the enclosure to provide a drain (45) for directing moisture to the outside of the box.
摘要:
Outbound signals carried over an electric power network are detected and crosstalk is rejected by sampling the waveform (V) in three segments (I, II, III) of each cycle. In the first segment (I) valid signals are always absent. Valid signals appear at the same time in both the second and third segments (II, III). Sample waveform values from alternate half cycles are compared to detect differences indicative of outbound signal information. The energy in each of the three segments (I, II, III) is compared with an energy threshold for that segment and a cycle under test is rejected when the energy in the first segment (I) exceeds the threshold for that first segment (I). A cycle under test is also rejected if the energy in the third segment (III) greatly exceeds the energy in the second segment (II). Signal detection thresholds for both signal strength and energy in the segments (I, II, III) are set recursively using actual samples acquired at the outbound detection site. These thresholds are sensitive to dynamic network changes.
摘要:
Outbound signals carried over an electric power network are detected and crosstalk is rejected by sampling the waveform (V) in three segments (I, II, III) of each cycle. In the first segment (I) valid signals are always absent. Valid signals appear at the same time in both the second and third segments (II, III). Sample waveform values from alternate half cycles are compared to detect differences indicative of outbound signal information. The energy in each of the three segments (I, II, III) is compared with an energy threshold for that segment and a cycle under test is rejected when the energy in the first segment (I) exceeds the threshold for that first segment (I). A cycle under test is also rejected if the energy in the third segment (III) greatly exceeds the energy in the second segment (II). Signal detection thresholds for both signal strength and energy in the segments (I, II, III) are set recursively using actual samples acquired at the outbound detection site. These thresholds are sensitive to dynamic network changes.