Abstract: A mosquito killing apparatus includes an electroshock unit to which a high voltage applies, a heater to generate heats, a carbon dioxide (CO2) gas introduction inlet connected to discharging portions for discharging carbon dioxide (CO2) gas around the electroshock unit, and a protection cover provided outside the electroshock unit for covering the electroshock unit. The carbon dioxide (CO2) gas introduction inlet can be connected to carbon dioxide (CO2) gas generating means of various types, and a carbon dioxide (CO2) gas staying unit is formed around the electroshock unit to stay the carbon dioxide (CO2) gas introduced from the carbon dioxide (CO2) gas introduction inlet to surely electrocute attracted mosquitoes.

Abstract: Single-phase currents at two frequencies f.alpha. and f.beta. (f.alpha.<n.multidot.fs<f.beta.) of non-integral multiples of a system fundamental wave frequency fs sandwiching an targeted harmonic (frequency n.multidot.fs) are injected between two phases of a three-phase power system as interharmonic currents. A frequency analysis of measurement current and measurement voltage of each phase in the system is carried out and a positive-phase-sequence current I1, a positive-phase-sequence voltage V1, a negative-phase-sequence current I2, and a negative-phase-sequence voltage V2 are detected for each of the two frequencies f.alpha. and f.beta. in the system based on injecting of the interharmonic currents. Positive-phase-sequence and negative-phase-sequence admittances Y1 and Y2 or positive-phase-sequence and negative-phase-sequence impedances Z1 and Z2 are found for each of the frequencies f.alpha. and f.beta. in the system as Y1=I1/V1 and Y2=I2/V2 or Z1=V1/I1 and Z2=V2/I2.