Abstract:
A watt-hour meter may include one or more electrical junction points that interface a Distributed Energy Resource to an energy-consuming structure and to the electrical distribution grid, while maintaining compliance with interconnection requirements for safety, power quality and automatic disconnect capabilities

Description:
BACKGROUND 
       [0001]    Distributed energy resources (DER) are smaller power sources that can be aggregated to provide power necessary to meet regular demand. As the electric grid continues to modernize, DERs such as photovoltaic solar panels, electric vehicles, energy storage batteries and advanced renewable technologies can help facilitate the transition to a smarter grid. Further, as developments in DER technologies progress, associated costs are falling, performance efficiencies are increasing, and demand for greater integration of disparate functionality is rising. 
       SUMMARY 
       [0002]    In an example, a watt-hour meter may include one or more electrical junction points that interface a Distributed Energy Resource to an energy-consuming structure and to the electrical distribution grid, while maintaining compliance with interconnection requirements for safety, power quality and automatic disconnect capabilities. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    The foregoing and other features of this disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. The use of the same reference numbers in different figures indicates similar or identical items. Further, understanding that these drawings depict only several embodiments in accordance with the disclosure and are, therefore, not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings, in which: 
           [0004]      FIG. 1  shows a side view of a junction meter, in accordance with at least some one of the embodiments described herein; 
           [0005]      FIG. 2  shows a flow chart representing the electrical and data connections between the various components within a junction meter, configured with a connection to a DER on the grid-side of the whole premises metering circuit, in accordance with at least some one of the embodiments described herein; 
           [0006]      FIG. 3  shows a flow chart representing the electrical and data connections between the various components within a junction meter, configured with a connection to a DER on the premises-side of the whole premises metering circuit, in accordance with at least some one of the embodiments described herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0007]    In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein. 
         [0008]      FIG. 1  shows a side view of junction meter  100 . Junction meter  100  facilitates installation of a DER at a customer site to accommodate the DER, as well as the installation of communications and other ancillary equipment, while also complying with safety codes and standards. 
         [0009]    Grid blades  1  are electrical interfaces through which electricity from electric power grid  35  may enter. 
         [0010]    Surge protection device  3  is a protective device that limits voltage supplied to junction meter  100  by either blocking or shorting to ground any unwanted voltages from the grid  35  above a defined threshold. 
         [0011]    Voltage sensors  5  are sensing devices that measure the voltage of power incoming through grid blades  1 . 
         [0012]    Whole premises relay  7  is a closable switch on a circuit that is used to remotely disconnect premises  33  from electrical grid  35 . 
         [0013]    Whole premises meter  9  is a metering device that measures power consumed or produced by premises  33 . 
         [0014]    DER connection point  19  is an interface through which power can also enter meter  100 . 
         [0015]    Second surge protection device  17  is a protective device that prevents power surges from entering junction meter  100  through DER connection point  19 . 
         [0016]    DER relay  15  is a closable switch on a circuit that is used to remotely electrically disconnect a DER attached to DER connection point  19 . 
         [0017]    Current sensor  13  is a sensor that, in combination with voltage sensor  5 , measures power produced or consumed by DER. 
         [0018]    Overcurrent protection device  11  is a protective device that prevents overcurrents from being drawn through DER connection point  19 . Overcurrent protection device  11  can be triggered to disconnect DER connection point  19  from grid  35  and premises  33  under a variety of grid conditions such as voltage spikes. 
         [0019]    Core processor  21  is a computing system that combines measurements from voltage sensor  5 , current sensor  13 , and whole premises meter  9  to gather and compute power consumption and production data for the premises  33  and the DER  37 . Core processor  21  also controls whole premises relay  7  and DER relay  15  by sending signals to open or close under a variety of conditions either sensed locally or determined via a signal from a transceiving station  39 . 
         [0020]    Communications module  25  is a microprocessor and modem that transmits metering data from the junction meter  100  to transceiving station  39 , or receives commands from the transceiving station  39 . Commands may include but are not limited to: changes to operating parameters such as the rate at which metering systems samples the power flow, and position of control relays. Display module  23  can display relevant metering data. Power is delivered to premises  33  through premises blades  27 . 
         [0021]    Housing  31  is an enclosure that combines with front cover  29  create a weatherproof containment for the junction meter components. 
         [0022]      FIG. 2  shows a flow chart representing the electrical and data connections between the various components within a junction meter, configured with a connection to a DER on the line-side of the whole premises metering circuit. 
         [0023]    Power enters the meter from the grid  35  through grid side blades  1 . Surge protection device  3  prevents power surges from the grid from passing into the meter. Voltage sensor  5  measures the voltage of the incoming power. Whole premises relay  7  is capable of remotely disconnecting the premises  33  from the electrical grid. Whole premises meter  9  can measure the power consumed or produced by the premises  33 . 
         [0024]    Power can also enter the meter through DER connection point  19 . A second surge protection device  17  prevents power surges from entering the meter through DER connection point  19 . DER relay  15  is capable of remotely disconnecting anything attached to DER connection point  19 . Current sensor  13 , combined with voltage sensor  5  can measure the power produced or consumed by the DER. Overcurrent protection device  11  can prevent overcurrents from being drawn through DER connection point  19 . Overcurrent protection device  19  can also be manually triggered to electrically disconnect DER connection point  11  from the grid  35  and premises  33 . 
         [0025]    Core processor  21  combines measurements from voltage sensor  5 , current sensor,  13 , and whole premises meter  9  to gather and compute power consumption and production data for the premises  33  and the DER  37 . Core processor  21  can also control whole premises relay  7  and DER relay  15 . Communications module  25  can transmit data from the junction meter to a transceiver station  39 , or receive commands from a transceiver station  39 . Display module  23  can display relevant metering data. Whole premise blades  27  connect the meter to the premises electrical system  33 . 
         [0026]    The electrical power connection with the DER takes place between the voltage sensor  5 , the whole premises relay  7 , and the DER connection point  11 . 
         [0027]      FIG. 3  shows a flow chart representing the electrical and data connections between the various components within a junction meter, configured with a connection to a DER  37  on the premises-side of the whole premises metering circuit. 
         [0028]    Power enters the meter through grid side blades  1 . Surge protection device  3  prevents power surges from the grid from passing into the meter. Voltage sensor  5  measures the voltage of the incoming power. Whole premises relay  7  is capable of remotely disconnecting the premises from the electrical grid  35 . Whole premises meter  9  can measure the power consumed or produced by the premises. 
         [0029]    Power can also enter the meter through DER connection point  19 . A second surge protection device  17  prevents power surges from entering the meter through DER connection point  19 . DER relay  15  is capable of remotely disconnecting anything attached to DER connection point  19 . Current sensor  13 , combined with voltage sensor  5  can measure the power produced or consumed by the DER. Overcurrent protection device  11  can prevent dangerous overcurrents from being drawn through DER connection point  19 . Overcurrent protection device  19  can also be manually triggered to disconnect DER connection point  11  from the grid and premises. 
         [0030]    Core processor  21  combines measurements from voltage sensor  5 , current sensor,  13 , and whole premises meter  9  to gather and compute power consumption and production data for the premises and the DER. Core processor  21  can also control whole premises relay  7  and DER relay  15 . Communications module  25  can transmit data from the junction meter to a receiving station, or receive commands from a transmitting station. Display module  23  can display relevant metering data. Whole premise blades  27  connect the meter to the premises electrical system. 
         [0031]    The electrical power connection with the DER takes place between the whole premise meter  9 , the overcurrent protection device  11 , and the whole premise blades  27 .