| 摘要 |
Power distribution networks increasingly need to monitor the electrical power at points distributed around the network in order to cope with feed-in tariffs, etc. A unit which senses the electrical characteristics of the network can also be used to sense other environmental characteristics of the electrical network at that location. We describe an electrical sensor unit (50) attachable to an insulated electrical distribution cable (88) and comprising at least one electrical sensor for at least one of current, voltage, and phase angle of electrical power being transmitted in the cable (88), a source of electrical power for driving the electrical sensors, and a socket for receiving an environmental sensor and comprising connections for the source of electrical power. This means that the unit can be deployed as a standard item at a cost comparable with a simple electrical sensor, and then if and when environmental sensing is desired at the location in question, then an environmental sensor can be added via the socket in order to upgrade that particular location. It is convenient for the unit to comprise an annular body defining an axial passage through which an electrical conductor (90) can pass, the annular body housing an electrical sensor in the form of a current sensor including a loop extending around the axial passage. This provides a convenient form for the unit which allows it to be fitted in place over an existing cable (88) without severing the cable. The environmental sensor can sense at least one of temperature, partial discharge, humidity, atmospheric pressure. Thus, the socket can be fitted a sensor apt to detect any or some of these, or a battery, or a blanking plug (80), for example if neither a battery nor a sensor is needed at that time. |
