电工进网作业许可考试复习题一(判断题)(高压)(2013年版)(国外英文资料).docVIP

电工进网作业许可考试复习题一(判断题)(高压)(2013年版)(国外英文资料) An electricians license exam for homework assignment one (question) (high pressure) (2013 edition) Release time: 2013-3-1 12:20:00 ? The voltage between the two phase lines is called line voltage. (? U?) The greater the flux, the stronger the magnetic field. (r)? 3, when the power waveform is not strictly sine wave, it will have a lot of higher harmonic components, the harm of the harmonic of electric equipment, can make the iron core of transformer loss increased, so that the transformer overheating, not only to increase energy consumption, and make its dielectric ageing speed, shorten service life. (u) 4, large power system form the ring, double loop network, the power supply to important users assured, when the system in a certain local equipment failure or part of the line need to repair, can through the change of power grid operation mode, the continuous power supply to the customer, reduce the loss caused by power failure. (? U) 5, the main characteristics of low resistance grounding mode is better to limit of single-phase grounding fault current, inhibition of arc grounding and resonance overvoltage, single-phase earth fault not immediately after the trip, not the burden of aggravating the insulation of the electrical equipment. (r)? 6, electricity production with power generation, power supply and utilization, the characteristics of the finished at the same time, determine the power generation, power supply and utilization must always maintain a balance, supply increase and decrease with the instantaneous increase or decrease in electricity. (u?) In a certain period of time, the phenomenon that the voltage varies sharply and deviates from the maximum is called voltage fluctuation. (r) The power plant is called hydroelectric power plant. (u?) The power supply for a class of load should be powered by two independent power sources, and when a power failure occurs, the other power supply should not be damaged at the same t