Apparatus and Methods Thereof for Power Consumption Measurement at Circuit Breaker Points

Abstract

Apparatus and methods are provided for the measurement of power consumption at points of interest, such as circuit breakers, machines, and the like. Accordingly, means are provided for measurement of power consumption for each electrical sub-network that is controlled by a circuit breaker. Each apparatus is enabled to communicate its respective data, in an environment of a plurality of such apparatuses, to a management unit which is enabled to provide finer granularity power consumption profiles. Challenges of measuring relatively low supply currents, wireless operation in an environment of a large number of apparatuses, and self-powering are addressed.

1 . An apparatus comprising:
 at least one analog section having a current transformer having a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section harvesting energy from a secondary winding wound around the transformer core, and storing harvested energy for use by components of the apparatus, the analog section providing an analog signal responsive to AC in the power line and a pulse having a frequency responsive to the alternating current in the AC power line;   a microcontroller coupled to the at least one analog section to receive energy for the operation of at least the microcontroller, and to receive the analog signal and the pulses;   a memory coupled to the microcontroller; and   a transmitter coupled to the microcontroller to transmit, under the control of the microcontroller, information responsive to at least one of the analog signal and the pulses as an indication of the power consumption of a load connected to the power line.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 a resonance capacitor coupled in parallel to the secondary winding of the current transformer.   
     
     
         3 . The apparatus of  claim 1 , further comprising one of:
 a diode bridge coupled in parallel to the secondary winding of the current transformer; or   a voltage multiplier coupled in parallel to the secondary winding of the current transformer.   
     
     
         4 . The apparatus of  claim 1 , wherein the transformer core comprises a first section having the secondary winding wound thereon, the first section and the second section fitting together such that the power line is surrounded by the transformer core by the first section and second section to achieve an essentially uninterrupted magnetic path around the power line. 
     
     
         5 . The apparatus of  claim 1 , wherein the number of turns in the secondary winding is greater than 500. 
     
     
         6 . The apparatus of  claim 1 , further comprising, in the analog section, a sense capacitor and circuitry for periodically discharging the sense capacitor for prevention of saturation of the core. 
     
     
         7 . The apparatus of  claim 1 , wherein the microcontroller operates in a continuous mode when sufficient energy is available from the analog section, and in the continuous mode, performs continuous measurements of the analog signal, stores information responsive to the continuous measurements and cause the transmission of the information using the transmitter. 
     
     
         8 . The apparatus of  claim 7 , wherein the continuous measurements include at least one of: peak detection, phase detection, power disruption. 
     
     
         9 . The apparatus of  claim 1 , further comprising a receiver coupled to the microcontroller. 
     
     
         10 . The apparatus of  claim 9 , wherein the receiver is enabled to perform at least one of: sense for a carrier signal, receive an acknowledge signal, receive a synchronization information. 
     
     
         11 . The apparatus of  claim 1 , wherein the memory contains calibration information of the apparatus. 
     
     
         12 . A system for power management comprising:
 at least one self-powered power sensor (SPPS) coupled around an alternating current (AC) power line;   a communication bridge adapted to communicate with the at least a SPPS and further coupled to a network;   a management server coupled to the network and adapted to receive information from the communication link respective of the at least one SPPS; and   a database coupled to the network for storing at least the information;   the SPPS having at least one analog section comprising a current transformer comprising a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section harvesting energy from a secondary winding wound the transformer core, and storing it for use by components of the apparatus and periodically providing a pulse having a frequency responsive to the alternating current in the AC power line; a microcontroller coupled to the at least one analog section to receive harvested energy, to receive at least an analog signal responsive to the alternating current in the AC power line, and the pulse; a memory coupled to the microcontroller; and, a transmitter enabled to periodically transmit, under the control of the microcontroller, information respective of the power consumption of the power line.   
     
     
         13 . The system of  claim 12 , further comprising:
 a client node coupled to the network and enabled to display at least information respective of the power consumed through the AC power line associated with the at least one SPPS.   
     
     
         14 . A method for sensing power consumption comprising:
 receiving a pulse from a current to pulse converter of an analog section of a self-powered power sensor (SPPS);   counting the number of pulses received;   activating a transmitter of the SPPS for transmission;   transmitting information respective of the number of pulses counted upon determination that the SPPS has accumulated sufficient power for transmission; and   deactivating the transmitter of the SPPS;   the SPPS having at least one analog section comprising a current transformer comprising a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section harvesting energy from a secondary winding wound around the transformer core, and storing it for use by components of the apparatus and periodically providing a pulse having a frequency responsive to the alternating current in the AC power line; a microcontroller coupled to the at least one analog section to receive harvested energy, to receive at least an analog signal responsive to the alternating current in the AC power line, and the pulse; a memory coupled to the microcontroller; and, a transmitter enabled to periodically transmit, under the control of the microcontroller, information respective of the power consumption of the power line.   
     
     
         15 . The method of  claim 14 , further comprising:
 activating a receiver of the SPPS to sense another transmission carrier signal;   enabling the transmission of the information if a receiver of the SPPS does not detect another transmission carrier signal; and   deactivating the receiver.   
     
     
         16 . The method of  claim 15 , further comprising:
 receiving a signal from a source.   
     
     
         17 . The method of  claim 16 , wherein the signal comprises at least one of: an acknowledge signal, synchronization information. 
     
     
         18 . A method for sensing power consumption comprising:
 receiving a first signal responsive of a primary current sensed by sensing resistor of an analog section of a self-powered power sensor (SPPS);   activating a transmitter of the SPPS for transmission;   transmitting information respective of the first signal upon determination that the SPPS has accumulated sufficient power for transmission; and   deactivating the transmitter of the SPPS;   the SPPS having at least one analog section comprising a current transformer comprising a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section harvesting energy from a secondary winding wound around the transformer core, and storing it for use by components of the apparatus and periodically providing a pulse having a frequency responsive to a current in the AC power line; a microcontroller coupled to the at least one analog section to receive harvested energy, to receive at least an analog signal responsive to the current in the AC power line, and the pulse; a memory coupled to the microcontroller; and, a transmitter enabled to periodically transmit, under the control of the microcontroller, information respective of the power consumption of the power line.   
     
     
         19 . The method of  claim 18 , further comprising:
 activating a receiver associated with the SPPS to sense another transmission carrier signal;   enabling the transmission of the information if a receiver of the SPPS does not detect another transmission carrier signal; and   deactivating the receiver.   
     
     
         20 . The method of  claim 19 , further comprising:
 receiving a second signal from a source.   
     
     
         21 . The method of  claim 20 , wherein the second signal comprises at least one of: an acknowledge signal, synchronization information. 
     
     
         22 . An apparatus comprising:
 at least one analog section comprising a current transformer comprising a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section for harvesting energy from a secondary winding wound the transformer core, and storing it for use by components of the apparatus and periodically switching to allow sampling of a current flowing through the current transformer by a sense resistor;   a microcontroller coupled to the at least one analog section to receive harvested energy, at least an analog signal responsive to the alternating current in the AC power line by the sense resistor;   a memory coupled to the microcontroller; and   a transmitter enabled to periodically transmit, under the control of the microcontroller, information responsive to the power consumption of a load connected to the power line.   
     
     
         23 . The apparatus of  claim 22 , wherein the switching comprises use of a first switch operative in the positive phase of the AC cycle and a second switch operative in the negative phase of the AC cycle. 
     
     
         24 . The apparatus of  claim 22 , wherein the sense resistor is coupled to a secondary winding of the current transformer, and has a resistance which is smaller than the resistance of the secondary winding. 
     
     
         25 . An apparatus comprising:
 at least one analog section comprising a current transformer comprising a transformer core configured to mount around an alternating current (AC) power line making it a primary winding of the current transformer, the analog section harvesting energy from a secondary winding wound around the transformer core, and storing it for use by components of the apparatus using a first secondary winding of the current transformer and a sense resistor coupled to a second secondary winding for sensing the current of the transformer;   a microcontroller coupled to the at least one analog section to receive harvested energy and at least an analog signal responsive to the alternating current in the AC power line by the sense resistor;   a memory coupled to the microcontroller; and   a transmitter enabled to periodically transmit, under the control of the microcontroller, information respective of the power consumption of a load connected to the power line.   
     
     
         26 . The apparatus of  claim 25 , wherein the sense resistor has a resistance which is smaller than the resistance of the second secondary winding of the current transformer. 
     
     
         27 . The apparatus of  claim 25 , further comprising:
 a resonance capacitor coupled in parallel to the secondary winding of the current transformer.   
     
     
         28 . The apparatus of  claim 25 , further comprising one of:
 a diode bridge coupled in parallel to the secondary winding of the current transformer; or   a voltage multiplier coupled in parallel to the secondary winding of the current transformer.