Electrified railway power grid system without negative sequence in whole process and without power supply networks at intervals

An electrified railway power grid system comprising:

• an external power supply system;
• an input power supply system from external to internal;
• and
• an internal power supply system;
• wherein the external power supply system comprises a first facility provided for an upline of a railway and a second facility provided for a downline of the railway;
• wherein the first and second facilities are parallel and symmetrical to each other;
• a plurality of positioners for cantilever provided at upper parts of a row of tension length supports, and two catenaries parallel to each other being fixed to each positioner;
• wherein each catenary is fixedly connected to one end of a hanger, and the other end of the hanger is connected to a power supply contact wire;
• wherein the two catenaries, connected hangers and power supply contact wires are parallel to each other and mutually insulated so as to prevent shorting;
• wherein the hangers are arranged between the catenaries and the power supply contact wires, and wherein the hangers are configured to transfer loads of the power supply contact wires to the catenaries, through which the loads are transferred to the tension length support;
• wherein in the input power supply system from external to internal, and first and second double-phase pantographs are provided on corresponding train tops of an eight-carriage motor train unit;
• wherein first and second slide contactors are respectively provided on an upper end of a left arm and an upper end of a right arm of each double-phase pantograph;
• wherein power of a first single-phase and power of a second single-phase from a secondary side of a traction transformer are connected to a first set and second set of double phase cut-off switches via the first and second slide contactors and input to the internal power supply system;
• wherein in the internal power supply system, a motive power supply and an auxiliary power supply of an eight-carriage motor train unit are configured for a first basic unit, and a train-mounted battery of a motor train unit is configured as a second basic unit;
• wherein the motor train unit is configured to successively run through a plurality of travel sections during operation;
• wherein when the first double-phase pantograph needs to rise, the second set of double-phase cut-off switches are turned off, and the first set of double-phase cut-off switches are turned on, so that a first phase of the first set of double-phase cut-off switches is responsible for power supply of the first basic unit of the motive power supply and the auxiliary power supply, and a second phase of the first set of double-phase cut-off switches is responsible for power supply of the second basic unit of the train-mounted battery;
• wherein when the motor train unit runs into a first travel section, the first double-phase pantograph rises, the second double-phase pantograph falls, the first slide contactor on the left arm of the first double-phase pantograph is connected to the first basic unit of the auxiliary power supply and the motive power supply of the motor train unit, and the second slide contactor on the right arm of the first double-phase pantograph is connected to the second basic unit of the train-mounted battery;
• wherein when the motor train unit runs into a third travel section, the second double-phase pantograph rises, the first double-phase pantograph falls, the first slide contactor on the right arm of the second double-phase pantograph is connected to the second basic unit of the train-mounted battery, and the second slide contactor on the left arm of the second double-phase pantograph is connected to the first basic unit of the auxiliary power supply and the motive power supply of the motor train unit;
• and
• as the first single phase and the second single phase draw power from a three-phase high-voltage power network independently at intervals, and the first and second double-phase pantographs rise or fall alternately, the first single phase and the second single phase can be symmetrically adjusted automatically, and thus two single-phase power lines are not provided with a neutral section for passing of phase separation, and a negative sequence current is not caused in the three-phase high-voltage power network.