System and method of measuring power produced by a power source

Abstract

Some embodiments relate to a system for measuring power produced by a power source. The system includes a first voltage sensor for sensing a first voltage difference between a first voltage and a second voltage and a second voltage sensor for sensing a second voltage difference between a third voltage and the second voltage. The system further includes a first current sensor for sensing a current difference between a first current and a second current, and a second current sensor for sensing a current difference between a third current and the second current. The system further includes a power measuring device that determines the power produced by the power source using the first and second voltage differences and the first and second current differences.

1 . A system for measuring power produced by a single-phase power source, the system comprising:
 a voltage sensor for sensing a voltage difference between a first voltage and a second voltage;   a current sensor for sensing a current difference between a first current and a second current; and   a power measuring device that determines the power produced by the single-phase power source using the voltage difference sensed by the voltage sensor and the current difference sensed by the current sensor.   
     
     
         2 . The system of  claim 1  wherein the voltage sensor measures the first voltage and measures the second voltage, and wherein the voltage sensor subtracts the second voltage from the first voltage to determine the voltage difference. 
     
     
         3 . The system of  claim 1  wherein the voltage sensor directly measures the voltage difference between the first voltage and the second voltage. 
     
     
         4 . The system of  claim 1  wherein the current sensor measures the first current and measures the second current, and wherein the current sensor subtracts the second current from the first current to determine the current difference. 
     
     
         5 . The system of  claim 1  wherein the current sensor directly measures the current difference between the first current and the second current. 
     
     
         6 . The system of  claim 5  further comprising a first conductor that carries the first current and a second conductor that carries the second current. 
     
     
         7 . The system of  claim 6  wherein the current sensor is a current transformer such that the first conductor extends through the current transformer and carries the first current in one direction and the second conductor extends through the current transformer and carries the second current in an opposite direction. 
     
     
         8 . A method of measuring power produced by a single phase power source comprising:
 measuring a voltage difference between a first line voltage and a second line voltage;   measuring a current difference between a first line current and a second line current; and   calculating power produced by the single-phase power source using the voltage difference and the current difference.   
     
     
         9 . The method of  claim 8  wherein measuring a voltage difference between the first line voltage and the second line voltage includes:
 measuring a first voltage; 
 measuring second voltage; and 
 calculating the voltage difference by subtracting the second voltage from the first voltage. 
 
     
     
         10 . The method of  claim 8  wherein measuring a voltage difference between the first line voltage and the second line voltage includes directly measuring the voltage difference. 
     
     
         11 . The method of  claim 8  wherein measuring a current difference between the first line current and the second line current includes:
 measuring a first current; 
 measuring a second current; and 
 calculating the current difference by subtracting the second current from the first current. 
 
     
     
         12 . The method of  claim 8  wherein measuring a current difference between the first line current and the second line current includes directly measuring the current difference. 
     
     
         13 . The method of  claim 8  wherein calculating power produced by a power source using the voltage difference and the current difference includes obtaining of an average of the product of the voltage difference and current difference over a period of time. 
     
     
         14 . A system for measuring power produced by a single-phase power source, the system comprising:
 a voltage sensor for sensing a voltage difference between a first voltage and a second voltage, wherein the first voltage is produced between a first line and a central connection point of the single phase power source and the second voltage is produced between a second line and the central connection point of the single phase power source;   a first conductor that carries a first current produced by the single-phase power source;   a second conductor that carries a second current produced by the single-phase power source;   a current sensor for sensing a current difference between the first current and the second current; and   a power measuring device that determines the power produced by the single-phase power source using the voltage difference sensed by the voltage sensor and the current difference sensed by the current sensor.   
     
     
         15 . The system of  claim 14  wherein the first voltage is 180 degrees out of phase with the second voltage. 
     
     
         16 . The system of  claim 14  wherein the central connection point is a neutral point providing a return path for an imbalanced current equal to the current difference between the first current and the second current. 
     
     
         17 . The system of  claim 14  wherein the first voltage and the second voltage are produced by two independent channels of a power source such that they produce current independent of each other. 
     
     
         18 . The system of  claim 17  wherein the power source is an engine-generator and the two independent channels are stator coils. 
     
     
         19 . The system of  claim 14  wherein the current sensor is a current transformer such that the first conductor extends through the current transformer and carries the first current in one direction and the second conductor extends through the current transformer and carries the second current in an opposite direction. 
     
     
         20 . The system of  claim 14  wherein the first current flows through the first conductor into a load and the second current flows through the second conductor into the load, and wherein a third current flows through a third conductor the central connection point.