POWER RELAY FOR SYSTEM INTERCONNECTION

• Main Authors: KAYAMA SHOZO, MAMORU MASATAKE, KANO SHUNSUKE, KIRIYAMA NORIO, YOKOMIZO MASAYOSHI
• Format: Patent
• Language: English
• Published: 04.10.2012
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

PROBLEM TO BE SOLVED: To provide an economical and compact reverse power relay which is used in system interconnection with a three-phase three-wire circuit and a single-phase three-wire circuit and the like and capable of preventing an unnecessary operation caused by an unbalanced local load or the like.SOLUTION: A power relay used in an electric circuit to which power is distributed via n tracks comprises: current input means for (n-1) electric circuits; respective voltage input means between other electric circuits different from the (n-1) electric circuits; a function to calculate single-circuit power per electric circuit and all-circuit power which is a sum of power per electric circuit; means for setting of setting values of power threshold values which serve as a reference for determining a magnitude of the calculated power and whether the power is positive or negative; and means for setting a power method which determines whether to apply the single-circuit power or the all-circuit power to the power to be compared with the threshold value. Operation and output of the power relay function are performed according to the set power threshold value and the power method of the set circuit.