Detecting device and method, and program

Abstract

The present invention relates to a detecting device and method, and a program which can detect a power state easily at low cost. A current transformer measures current of a commercial power system from a commercial power supply through a connection point of the commercial power system and a power generation system from a solar power generation system that supplies power having the same frequency as the commercial power supply. A current transformer measures power at the power generation system side through the connection point. A decision value calculator calculates a decision value based on a value obtained through multiplication of a measured value of current through the current transformer and through the current transformer. A flow detector detects a power flow of the commercial power system based on the calculated value. The present invention can be applied to a power measuring system for use in homes, for example.

1 . A detecting device configured to detect a power state, comprising:
 a first current transformer configured to measure first current at a side of a first power system from a commercial power supply through a connection point of the first power system and a second power system from a power generator configured to supply power having the same frequency as the commercial power supply;   a second current transformer configured to measure second current at the second power system side through the connection point;   a first calculator configured to calculate a decision value based on a value obtained through multiplication of a measured value of the first current and that of the second current; and   a detector configured to detect a power flow of the first power system based on the decision value.   
     
     
         2 . The detecting device according to  claim 1 , wherein the detector decides that the power flow of the first power system is a direction in which power is supplied from the commercial power supply regardless of the decision value if an effective value of the first current is greater than that of the second current. 
     
     
         3 . The detecting device according to  claim 1 , wherein the detector decides that the power flow of the first power system is a direction in which power is supplied from the commercial power supply if the effective value of the second current is equal to or smaller than a specified value. 
     
     
         4 . The detecting device according to  claim 1 , wherein the first calculator calculates, as the decision value, an integrated value of the multiplied value for n cycles (n is a natural number) of the power of the commercial power supply. 
     
     
         5 . The detecting device according to  claim 1 , wherein the first calculator is calculated, as the decision value, a value obtained through multiplication of the measured value of the first current and that of the second current when the second current reaches a positive or negative peak. 
     
     
         6 . The detecting device according to  claim 1 , further comprising a second calculator configured to calculate first power to be supplied from the commercial power supply to the first power system and second power to be supplied from the power generator to the first power system based on the measured value of the first current and the power flow of the first power system. 
     
     
         7 . The detecting device according to  claim 6 , wherein the second calculator further calculates third power to be supplied to a load connected to the connection point based on the measured value of the first current, the measured value of the second current and the power flow of the first power system. 
     
     
         8 . The detecting device according to  claim 6  further comprising a display configured to display the first power and the second power. 
     
     
         9 . The detecting device according to  claim 6 , further comprising a communicator configured to transmit, to an outside, information including at least one combination in the first power and the second power, and the measured value of the first current and the power flow of the first power system. 
     
     
         10 . A method of detecting a power state by a detecting device, comprising the steps of:
 measuring first current by a first current transformer at a side of a first power system from a commercial power supply through a connection point of the first power system and a second power system from a power generator configured to supply power having the same frequency as the commercial power supply and measuring second current by a second current transformer at the second power system side through the connection point;   calculating a decision value based on a value obtained through multiplication of a measured value of the first current and that of the second current; and   detecting a power flow of the first power system based on the decision value.   
     
     
         11 . A detecting device comprising:
 a calculator configured to calculate a decision value based on a value obtained through multiplication of a measured value of first current measured by a first current transformer at a side of a first power system from a commercial power supply through a connection point of the first power system and a second power system from a power generator configured to supply power having the same frequency as the commercial power supply and a measured value of second current measured by a second current transformer at the second power system side from the connection point; and   a detector configured to detect a power flow of the first power system based on the decision value.   
     
     
         12 . A method of detecting a power state by a detecting device, comprising the steps of:
 calculating a decision value based on a value obtained through multiplication of a measured value of first current measured by a first current transformer at a side of a first power system from a commercial power supply through a connection point of the first power system and a second power system from a power generator configured to supply power having the same frequency as the commercial power supply and a measured value of second current measured by a second current transformer at the second power system side from the connection point; and   detecting a power flow of the first power system based on the decision value.   
     
     
         13 . A non-transitory computer readable storage medium encoded with an executable computer program for detecting a power state and that, when executed by a processor, causes the processor to perform operations comprising:
 calculating a decision value based on a value obtained through multiplication of a measured value of first current measured by a first current transformer at a side of a first power system from a commercial power supply through a connection point of the first power system and a second power system from a power generator configured to supply power having the same frequency as the commercial power supply and a measured value of second current measured by a second current transformer at the second power system side from the connection point; and   detecting a power flow of the first power system based on the decision value.