towed load การใช้

• Fristly , according to the non - linear characteristics of twelve - phase rectifier , the thesis gives the calculation model for a short circuit in the subway traction power supply networks which provides the academic foundation for the design of the setting values and the simulation of protection . secondly , the thesis designs the dc feeder protection and control of subway , and gives the principle of setting accordingly , after it analysizes the characteristics of electric current under tow load and short circuit and considers severel factors . to validate the rationality of the design , the thesis simulates the transient electric current under two work conditions ( starting and passing the insulation ) ahd short circuit