ELECTRIFIED RAILWAY POWER GRID SYSTEM WITHOUT NEGATIVE SEQUENCE IN WHOLE PROCESS AND WITHOUT POWER SUPPLY NETWORKS AT INTERVALS

Abstract

An electrified railway power supply system without negative sequence in the whole process and without power supply networks at intervals, can comprise an external power supply system, an input power supply system from external to internal, and an internal power supply system. For external power supply, single-phase power supply is changed to double-phase power supply, and power of a single phase is input to the power supply system within the train via a contactor on a left arm and a right arm of a double-phase pantograph. No neutral section for passing of phase separation is provided in the whole process of operation, and a plurality of sections in the whole process are provided with no power supply network at intervals, and the motor train unit can operate normally without mechanical support for the power supply network.

Claims

1. An electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals, comprising: an external power supply system; an input power supply system from external to internal; and an internal power supply system, wherein: in the external power supply system, one facility is provided for an upline and a downline of a railway respectively, and thus two facilities are provided; the two facilities are parallel and symmetrical to each other, and the two facilities are identical, for both of the two facilities; a plurality of positioners for cantilever are provided at upper parts of a row of tension length supports, and two catenaries parallel to each other are fixed to each positioner for cantilever; 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; the two catenaries, the two hangers and the two power supply contact wires are parallel to each other and mutually insulated to ensure shorting never occurs; and the hanger is arranged between the catenary and the power supply contact wire, and transfers all load of the power supply contact wire to the catenary, through which the load is transferred to the tension length support.

2. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 1, wherein: in the input power supply system from external to internal, double-phase pantographs T1 and T2 are provided on corresponding train tops of an eight-carriage motor train unit of CRH1-type, CRH2-type, CRH3-type, or CRH5-type; slide contactors ? and ? are respectively provided on an upper end of a left arm La and an upper end of a right arm Ra of each double-phase pantograph; and power of a single-phase ? and power of a single-phase ? from a secondary side of a traction transformer are connected to double phase cut-off switches K1? and K1? or K2? and K2? via the slide contactors ? and ?, and input to the internal power supply system.

3. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 2, wherein: in the internal power supply system, motive power supply and auxiliary power supply of any eight-carriage motor train unit are configured for a basic unit TUB1, and a train-mounted battery of any motor train unit is configured as a basic unit TUB2; the motor train unit successively runs through a plurality of travel sections including travel sections L11, L12, L21, L22, L32 and the like during operation; when the double-phase pantograph T1 needs to rise, firstly the double-phase cut-off switches K2? and K2? are turned off, and the double-phase cut-off switches K1? and K1? are turned on, so that the phase ? of the double-phase cut-off switches K1? is responsible for power supply of the basic unit TUB1 of motive power supply and auxiliary power supply, and the phase ? of the double-phase cut-off switches K1? is responsible for power supply of the basic unit TUB2 of the train-mounted battery; when the motor train unit runs into the travel section L11, the double-phase pantograph T1 rises, the double-phase pantograph T2 falls, the slide contactor ? on the left arm of the double-phase pantograph T1 is connected to the basic unit TUB1 of auxiliary power supply and motive power supply of the motor train unit, and the slide contactor on the right arm of the double-phase pantograph T1 is connected to the basic unit TUB2 of the train-mounted battery; when the motor train unit runs into the travel section L21, the double-phase pantograph T2 rises, the double-phase pantograph T1 falls, the slide contactor ? on the left arm of the double-phase pantograph T2 is connected to the basic unit TUB2 of the train-mounted battery, and the slide contactor ? on the right arm of the double-phase pantograph T2 is connected to the basic unit TUB1 of auxiliary power supply and motive power supply of the motor train unit; as the single phase ? and the single phase ? draw power from a three-phase high-voltage power network independently at intervals, and the double-phase pantographs T1 and T2 rise or fall alternately, the single phase ? and the 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.

4. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 3, wherein: the single phase ? and the single phase ? draw power from the three-phase high-voltage power network independently at intervals, and the double-phase pantographs T1 and T2 rise or fall alternately; and the single phase ? and the single phase ? will not cause an increase of an accumulated negative sequence current in the three-phase power network.

5. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 3, wherein, when the motor train unit runs into the travel section L12, L22 or L32; both the double-phase pantographs T1 and T2 fall, and operation of the motor train unit in the travel section L12 completely relies on electric energy stored in the travel section L11; operation of the motor train unit in the travel section L22 completely relies on electric energy stored in the travel section L21; operation of the motor train unit in the travel section L32 completely relies on electric energy stored in the travel section L31; and thus, in the travel section L12, L22 and L32, neither an overhead contact system for power supply nor a support structure for a power supply network is required, and the motor train unit can operate normally.

6. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 4, wherein, when the motor train unit runs into the travel section L12, L22 or L32; both the double-phase pantographs T1 and T2 fall, and operation of the motor train unit in the travel section L12 completely relies on electric energy stored in the travel section LL11; operation of the motor train unit in the travel section L22 completely relies on electric energy stored in the travel section L21; operation of the motor train unit in the travel section L32 completely relies on electric energy stored in the travel section L31; and thus, in the travel section L12, L22 and L32, neither an overhead contact system for power supply nor a support structure for a power supply network is required, and the motor train unit can operate normally.

7. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 4, wherein: none of the travel sections L12, L22 and L32 is provided with a traction power network; and tunnels, viaducts, station yards, culverts and the like are intentionally provided in the travel sections L12, L22 and L32 in line designing.

8. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 5, wherein: none of the travel sections L12, L22 and L32 is provided with a traction power network; and tunnels, viaducts, station yards, culverts and the like are intentionally provided in the travel sections L12, L22 and L32 in line designing.

9. The electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals of claim 1, wherein: the tension length supports and the positioners for cantilever provided on the outer side of the upline or the downline are respectively designed to be L-type; and the tension length supports and the positioners for cantilever arranged between the upline and the downline are designed to be T-type.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is schematic front view of an electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals according to a preferred embodiment of the present invention;

[0023] FIG. 2 is a schematic bottom view of FIG. 1;

[0024] FIG. 3(a) is a side view along line B1-B1 of FIG. 1, and FIG. 3(b) is a side view along line B2-B2 of FIG. 1;

[0025] FIG. 4 is a schematic diagram of a motive power supply and auxiliary power supply load and a train-mounted battery of an eight-carriage motor train unit;

[0026] FIG. 5 is a schematic diagram of external single-phase power supply of an existing electrified railway;

[0027] FIGS. 6(a)-6(d) are schematic diagram of arrangement sequences and placement positions of double-phase pantographs of four eight-carriage motor train units of different types, wherein

[0028] FIG. 6(a) is a schematic diagram of grouping of CRH1-type motor trains;

[0029] FIG. 6(b) is a schematic diagram of grouping of CRH2-type motor trains;

[0030] FIG. 6(c) is a schematic diagram of grouping of CRH3-type motor trains; and

[0031] FIG. 6(d) is a schematic diagram of grouping of CRH5-type motor trains.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Specific embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0033] As shown in FIG. 1, an electrified railway power grid system without negative sequence in the whole process and without power supply networks at intervals according to a preferred embodiment of the present invention comprises tension length supports. Positioners for cantilever are fixed to upper parts of the tension length supports, and two parallel catenaries are fixed to each positioner for cantilever, with a distance of 1.94 m between the catenaries. Hangers are disposed between the catenaries and contact wires. The upper ends of the two parallel hangers are connected to the two catenaries, and the lower ends of the two hangers are connected to the two contact wires. The two parallel contact wires are respectively connected to two lines of single-phase power ? and ? output from a secondary side of a traction transformer S. Two line structures insulated from and parallel to each other are provided on an upline and a downline of a railway. Positioners for cantilever 3 are provided at upper parts of each row of tension length supports 2, and two catenaries 4 parallel to each other are fixed to each positioner for cantilever 3. Hangers 5 are provided between the catenaries 4 and the two single-phase power supply contact wires 1. The spacing between every adjacent two positioners for cantilever 3 for each tension length is 35-45 m. The spacing between every adjacent two hangers 5 for each tension length is 7.5-8.5 m. The spacing between the two parallel hangers on each positioner for cantilever 3 is not less than 1.94 m. The hangers 5 transfer all weights of the power supply contact wires 1 to the catenaries 4, and the catenaries 4 transfer all equipment load of the power supply contact wires 1 to the tension length supports 2. As shown in FIG. 2, three-phase (A, B and C) high-voltage special power of 110 KV (220 KV for high-speed trains) is input to a primary side of the traction transformer S, and two lines of single-phase power ? and ? of 27.5 KV (the rated voltage is 25 KV) are output from the secondary side of the traction transformer S. The single-phase power ? and the single-phase power ? are connected to the two power supply contact wires 1. Large-current dropping resistors R.sub.? and R.sub.? of 200 ?-1800 ? are provided at start points and end points of the two single-phase power supply wires, to avoid such phenomena as a break spark and ferromagnetic resonance due to instantaneous break. A support structure in three-line arrangement can be set for the upline and the downline of the railway, wherein the tension length supports and the cantilevers on lateral sides of the upline and the downline may be designed into L-type (L-shaped), and the tension length supports and the positioners for cantilever arranged between the upline and the downline may be designed into be T-type (T-shaped), which not only saves the cost of project construction, but also improves the stability, reliability and safety of the support structure of the special power network. As shown in FIG. 3, a double-phase pantograph T1 and a double-phase pantograph T2 are provided on corresponding train tops of a motor train unit. A slide contactor ? and a slide contactor ? are respectively provided on an upper end of a left arm La and an upper end of a right arm Ra of each double-phase pantograph. The slide contactor ? and the slide contactor ? are in good slide contact with the two single-phase power supply wires. Insulators M.sub.1 and M.sub.2 are provided between the left arm La and the right arm Ra of the double-phase pantograph. The spacing between the left arm La and the right arm Ra of the double-phase pantograph is not less than 1.94 m. Power is transferred from the slide contactor ? and the slide contactor ? to the power supply system inside the motor train unit via the left arm La and the right arm Ra of the double-phase pantograph, which has the advantages of stable and smooth mechanical contact, reduced wear of pantograph-catenary contact, more reliable electric energy transmission, and high quality of power supply, as compared with the case of only providing one single-phase contactor in the middle of the pantograph.

[0034] As shown in FIG. 4, the two feeder lines of the single-phase power ? and the single-phase power ? are transferred from the slide contactor ? and the slide contactor ? to the power supply system inside the motor train unit via the left arm La and the right arm Ra of the double-phase pantograph; and the single-phase power ? and the single-phase power ? are connected to double-phase cut-off switches K1? and K1?, or are connected to double-phase cut-off switches K2? and K2?.

[0035] According to the present invention, the motor train unit will successively run through a plurality of travel sections including travel sections L.sub.11, L.sub.12, L.sub.21 L.sub.22, L.sub.32 and the like during operation.

[0036] To sum up, when the motor train unit runs to the travel section L11, the double-phase pantograph T1 rises, the double-phase pantograph T2 falls, the double-phase cut-off switch K2? and K2? are turned off, the double-phase cut-off switch K1? is connected to a basic unit TUB1 of motive power supply and auxiliary power supply within the motor train unit, and the double-phase cut-off switch K1? is connected to a basic unit TUB2 of a train-mounted (storage) battery. When the motor train unit runs into the travel section L.sub.12 after passing the travel section L.sub.11, electric energy stored by the train-mounted battery in the travel section L.sub.11 is sufficient to provide the motive power supply and auxiliary power supply needed by the motor train unit in the travel section L.sub.12, and both the double-phase pantographs T1 and T2 fall in the travel section L.sub.12. When the motor train unit runs into the travel section L.sub.21, the double-phase pantograph T1 falls, the double-phase pantograph T2 rises, the double-phase cut-off switch K1? and K1? are turned off, the double-phase cut-off switch K2? is connected to the basic unit TUB2 of the train-mounted battery, and the double-phase cut-off switch K2? is connected to the basic unit TUB1 of motive power supply and auxiliary power supply within the motor train unit; electric energy stored by the train-mounted battery in the travel section L.sub.11 is sufficient to provide the motive power supply and auxiliary power supply needed for the travel section L.sub.22; and both the double-phase pantographs T1 and T2 fall in the travel section L.sub.22. When the motor train unit further runs into the travel section L.sub.31, the double-phase pantograph T1 rises, the double-phase pantograph T2 falls, the double-phase cut-off switch K2? and K2? are turned off, the double-phase cut-off switch K1? is connected to the basic unit TUB1 of motive power supply and auxiliary power supply within the motor train unit, and the double-phase cut-off switch K1? is connected to the basic unit TUB2 of the train-mounted battery; electric energy stored by the train-mounted battery in the travel section L.sub.31 is sufficient to provide the motive power supply and auxiliary power supply needed by the motor train unit in the travel section L.sub.32; and both the double-phase pantographs T1 and T2 fall in the travel section L.sub.32. By analogy, the double-phase pantograph T1 rises, the double-phase pantograph T2 falls, the double-phase pantograph T1 falls, and the double-phase pantograph T1 rises. Hence, the basic unit TUB1 and the basic unit TUB2 draw power from the power network alternately. According to the present invention, as the motive power supply and auxiliary power supply within the train are configured for the basic unit TUB1, and the train-mounted battery power supply is configured for the basic unit TUB2, the electric quantity needed for the motive power supply and auxiliary power supply within the train is just approximate to that needed for the train-mounted battery power supply. In respective sections, every time the double-phase pantograph T1 rises, the single-phase ? is always connected to the basic unit TUB1, and the single-phase ? is always connected to the basic unit TUB. Every time the double-phase pantograph T2 rises, if the single phase ? is still connected to the basic unit TUB1, and the single phase ? is still connected to the basic unit TUB2, an accumulated error will be added to the single phase ? and the single phase ? respectively because the electric quantity needed for the basic unit TUB1 is just approximate to that needed for the basic unit TUB2. In a three-phase power network, the accumulated error will add a negative sequence current to the three-phase power network due to asymmetry of single phase power. If the basic unit TUB1 and the basic unit TUB2 alternately draw power from the power network every time the double-phase pantograph T1 rises or the double-phase pantograph T2 rises, the negative sequence current caused by asymmetry of power drawing error accumulation will be reduced in the whole process. Evidently, the above problem is solved desirably in the present invention, whereby power supply imbalance of the three-phase high-voltage power network due to accumulation of electric quantity will not occur, and negative effect of the negative sequence current is reduced. In summary, when the motor train unit runs to the travel section L.sub.12, L.sub.22, L.sub.32 or the like, both the double-phase pantographs T1 and T2 fall, and operation of the motor train unit in the travel section L.sub.12 completely relies on the electric energy stored in the travel section L.sub.11; operation of the motor train unit in the travel section L.sub.22 completely relies on the electric energy stored in the travel section L.sub.21; and operation of the motor train unit in the travel section L.sub.32 completely relies on the electric energy stored in the travel section L.sub.31. In the travel section L.sub.12, L.sub.22 and L.sub.32, neither an overhead contact system (contact network) for power supply nor a support structure for the power supply network is required, and the motor train unit can continue operating normally completely relying on the electric energy stored by the train-mounted battery in the travel section L.sub.11, L.sub.22 and L.sub.32. Thus, the design objective of no negative sequence current in the whole process and no power network support structure in sections of the invention can be achieved.

[0037] An exemplary application of the present invention in high-speed electrified trains is described below in conjunction with FIGS. 6(a)-6(d).

[0038] High-speed electrified trains in China at present are divided into four types, which are all eight-carriage motor train units. According to the present invention, single-phase pantographs originally provided on different train tops of a motor train unit are improved into double-phase pantographs. As shown in FIG. 6(a), double-phase pantographs of an eight-carriage motor train unit of CRH1-type are provided on tops of a second carriage as a trailer and a seventh carriage as a trailer. As shown in FIG. 6(b), double-phase pantographs of an eight-carriage motor train unit of CRH2-type are provided on tops of a fourth carriage as a trailer and a sixth carriage as a motor train. As shown in FIG. 6(c), double-phase pantographs of an eight-carriage motor train unit of CRH3-type are provided on tops of a second carriage as a trailer and a seventh carriage as a trailer. As shown in FIG. 6(d), double-phase pantographs of an eight-carriage motor train unit of CRH4-type are provided on tops of a third carriage as a trailer and a sixth carriage as a trailer. When the double-phase pantograph T1 rises, the double-phase pantograph T2 must fall, or when the double-phase pantograph T1 falls, the double-phase pantograph T2 must rise. The two lines of single-phase power ? and single-phase power ? output from the secondary side of the traction transformer S pass through the slide contactor ? and the slide contactor ? on the upper end of the left arm La and the upper end of the right arm Ra of the double-phase pantograph respectively, and are input into the motor train unit via the double-phase cut-off switch K1? and K1? or K2? and K2?.

[0039] The present invention is described above in detail in conjunction with specific embodiments. Apparently, what is described above and shown in the drawings should be interpreted as exemplary rather than limiting the present invention. To those skilled in the art, upon reading the present invention, apparently various variations or modifications can be made to the features described therein or combinations thereof, and all these variations or modifications should be encompassed within the protection scope of the present invention.

LIST OF REFERENCE SIGNS

[0040] A, B, C: three-phase high-voltage special power network [0041] D: motor train [0042] F: feeder line [0043] G: generator [0044] R: rail [0045] S: traction transformer [0046] T: overhead contact system [0047] ?, ?: two lines of single-phase power [0048] T1, T2: double-phase pantograph [0049] TM1: boosting transformer [0050] TM2: step-down transformer [0051] K1?, K1? and K2?, K2?: double-phase cut-off switch [0052] R.sub.? and R?: large-current dropping resistor [0053] ? and ?: slide contactors on an upper end of a left arm La and an upper end of a right arm Ra [0054] M1, M2: insulator between the left arm La and the right arm Ra [0055] 1: power supply contact wire [0056] 2: tension length support [0057] 3: positioner for cantilever [0058] 4: catenary [0059] 5: hanger