Electric power distribution system including metering function and method of evaluating energy metering

Abstract

An electric power distribution system is used with an electric power source. The electric power distribution system includes a first device exchanging first electric power with the electric power source. The first device exchanges the first electric power with a plurality of second devices and meters first electric energy corresponding to the first electric power. The second devices exchange the first electric power with the first device. Each of the second devices exchanges second electric power as at least part of the first electric power with a number of corresponding electric loads and meter second electric energy corresponding to the second electric power. A processor includes a routine that compares the metered first electric energy from the first device with a sum of the metered second electric energy from each of the second devices, and responsively determines proper or improper operation of the electric power distribution system.

What is claimed is: 
     
         1 . An electric power distribution system for use with an electric power source, said electric power distribution system comprising:
 a main circuit breaker structured to receive first electric power from the electric power source, the main circuit breaker including a first metering circuit being structured to meter power flowing through the main circuit breaker with 0.2% accuracy; and   a number of branch circuit breakers structured to receive second electric power from the main circuit breaker, each of the number of branch circuit breakers including a second metering circuit structured to meter power flowing through the branch circuit breaker with ±0.2% accuracy.   
     
     
         2 . The electric power distribution system of  claim 1 , wherein the main circuit breaker includes a processor comprising a routine structured to determine improper operation of at least one of the number of branch circuit breakers when the metered power flowing through the main circuit breaker is greater than a sum of the metered power flowing through the number of branch circuit breakers. 
     
     
         3 . The electric power distribution system of  claim 2 , wherein said routine is further structured to determine which one of the number of branch circuit breakers failed responsive to said determined improper operation. 
     
     
         4 . The electric power distribution system of  claim 3 , wherein said routine is further structured to determine which one of the number of branch circuit breakers failed by evaluating temperature versus time information and energy versus time information for a number of the number of branch circuit breakers. 
     
     
         5 . The electric power distribution system of  claim 3 , wherein said routine is further structured to determine which one of the number of branch circuit interrupters failed by evaluating at least one of: expected energy versus time information, power source or power sink with actual energy versus time information; and load type or rated current with actual current versus time information, for a number of the number of branch circuit interrupters. 
     
     
         6 . The electric power distribution system of  claim 3 , wherein said routine is further structured to determine which one of the number of branch circuit breakers failed by evaluating at least one of: installation date; and number of operating cycles, for a number of the number of branch circuit breakers. 
     
     
         7 . The electric power distribution system of  claim 1 , wherein each of the number of branch circuit breakers are structured to provide at least one of overcurrent protection, short circuit protection, ground fault protection, arc fault protection, overvoltage protection, and undervoltage protection. 
     
     
         8 . The electric power distribution system of  claim 1 , wherein each of the number of branch circuit breakers are structured to provide time stamped values of net energy and peak demand in a predetermined window size. 
     
     
         9 . The electric power distribution system of  claim 1 , wherein at least one of the number of branch circuit breakers is structured to generate an electric vehicle charging pilot signal. 
     
     
         10 . The electric power distribution system of  claim 9 , where the at least one of the number of branch circuit breakers is structured to provide a load interlock and a safe automatic reset. 
     
     
         11 . A circuit breaker structured to electrically connect between a power source and a load, the circuit breaker comprising:
 a protection unit structured to provide at least one of overcurrent protection and short circuit protection;   a metering unit structured to meter power flowing through the circuit breaker with utility grade accuracy; and   a memory structured to receive and store an output of the metering unit.   
     
     
         12 . The circuit breaker of  claim 11 , wherein the metering unit is structured to meter power flowing through the circuit breaker with ±0.2 accuracy. 
     
     
         13 . The circuit breaker of  claim 11 , wherein the metering unit includes:
 a number of current sensors;   a number of voltage sensors;   a power metering circuit structured receive outputs of the number current and voltage sensors and output energy values;   a timer structured output time values; and   a logic circuit structured to receive energy values from the power metering circuit and time values from the timer and to output time-stamped energy values to the memory.   
     
     
         14 . The circuit breaker of  claim 11 , further comprising:
 controllable separable contacts; and   a communication circuit structured to receive communications from an external device,   wherein the circuit breaker is structured to open or close the controllable separable contacts in response to communications from the external device.   
     
     
         15 . The circuit breaker of  claim 11 , further comprising:
 an external circuit breaker handle structured to cooperate with the protection unit to open, close, or reset separable contacts associated with the protection unit.   
     
     
         16 . The circuit breaker of  claim 11 , further comprising:
 a breaker stab structured to electrically connect to a busbar and to receive power from the power source; and   a neutral pigtail structured to electrically connect to a neutral bar.   
     
     
         17 . A circuit breaker structured to electrically connected between a power source and an electric vehicle, the circuit breaker comprising:
 a protection unit structured to provide at least one of overcurrent protection and short circuit protection;   controllable separable contacts;   a module structured to generate an electric vehicle charging pilot signal and to control the controllable separable contacts to open or close;   a metering unit structured to meter power flowing through the circuit breaker with utility grade accuracy; and   a memory structured to receive and store an output of the metering unit.   
     
     
         18 . The circuit breaker of  claim 17 , wherein the metering unit is structured to meter power flowing through the circuit breaker with ±0.2 accuracy. 
     
     
         19 . The circuit breaker of  claim 17 , wherein the metering unit includes:
 a number of current sensors;   a number of voltage sensors;   a power metering circuit structured receive outputs of the number current and voltage sensors and output energy values;   a timer structured output time values; and   a logic circuit structured to receive energy values from the power metering circuit and time values from the timer and to output time-stamped energy values to the memory.   
     
     
         20 . The circuit breaker of  claim 17 , wherein the protection unit is structured to provide load interlock and safe automatic reset.