Electronically switched voltage phase-shifting method-based live automatic phase-crossing passing system

Abstract

The present application relates to a charged automatic neutral section passing system based on electronic switch switching voltage phase-shifting mode, comprising a plurality of electronic switches composed of a plurality of semiconductor switch valves, one or two auxiliary winding transformers with a plurality of intermediate taps or without intermediate taps, and a control unit. The charged automatic neutral section passing system based on electronic switch switching voltage phase-shifting mode uses electronic switches and transformers to superimpose alternating voltages of different phases and different amplitudes to obtain intermediate phase-shifting transition voltage, so as to realize the step-by-step phase-shifting transition of the neutral section catenary voltage from one phase power supply arm voltage to another phase power supply arm voltage via the intermediate phase-shifting transition voltage, so as to eliminate the influence of the electric neutral section on train operation. The present application provides a new solution for solving the problem of train passing neutral section of AC electrified railway.

Description

Technical Field

[0001] This invention relates to the field of electrified railway phase transition technology, and more particularly to an automatic phase transition system for energized trains based on ground switch switching control. Background Technology

[0002] my country's AC electrified railways adopt a 25k / 50Hz single-phase power frequency supply method, with each phase of the three-phase power grid supplied in turn. To prevent short circuits between different phases during turn-sequence power supply, a section of contact network with electrical segments at both ends is installed at the traction substation outlet and the sectioning station at the end of the power supply arm; this is known as electrical phase separation. Electrical phase separation can be classified into two types according to its implementation: device-type and articulated-type. Currently, the articulated-type electrical phase separation is more commonly used, mainly consisting of a neutral zone contact network and anchor joints at both ends. The process of a train passing through an electrical phase separation is called phase crossing.

[0003] In practice, various energized automatic phase transition schemes for supplying power to trains by energizing the neutral zone contact network have been put into trial operation. Based on the way the neutral zone contact network obtains voltage, they can be divided into two main categories: The first category is the switch-switching voltage method, which directly switches the neutral zone contact network voltage from one phase power supply arm voltage to another phase power supply arm voltage by opening and closing different switches; the second category is the inverter voltage phase shifting method, which gradually shifts the neutral zone contact network voltage from one phase power supply arm voltage to another phase power supply arm voltage by changing the phase of the inverter output voltage.

[0004] The first type of automatic phase-crossing scheme using voltage switching includes two types: mechanical switch switching and electronic switch switching. The disadvantages of mechanical switch switching are short switch lifespan, high failure rate, and a power outage time of over 100ms between the two switches, making precise control of the action time impossible and causing overvoltage and overcurrent problems. The ground-based automatic phase-crossing scheme based on electronic switch switching mainly uses a fast electronic switch composed of thyristor series valve groups to replace the mechanical vacuum switch, overcoming the disadvantages of short lifespan and high failure rate of mechanical switches. Furthermore, the time interval between the two switches is shortened to the millisecond level, allowing for precise control of the action time and effectively solving the overvoltage and overcurrent problems during switch operation. However, since the phase difference between the two phase power supply arms in most electrified railway traction substations in my country is 60° and 90°, the electric locomotive grid-side voltage of this scheme and the mechanical switch scheme can only switch directly between the power supply arm voltages. This results in a large phase change in a short time, which can significantly affect the AC locomotive phase-locked loop and four-quadrant rectifier, potentially causing the train's main circuit breaker to trip.

[0005] With the development of voltage phase shifting automatic phase transition schemes for inverters, these schemes are conventionally referred to as power electronic converter-based automatic phase transition schemes. This type of scheme enables a smooth and flexible switching of the power supply voltage from one phase to another during the phase transition process, eliminating the impact of phase transition on train operation. However, its hardware is expensive and the system requires a large area for installation, resulting in high overall investment costs and making it difficult to promote its application. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a live automatic phase transition system based on electronic switch voltage phase shifting. By combining electronic switches and transformers, several intermediate phase-shifting transition voltages with phases between the voltages of two power supply arms are obtained. This allows the neutral zone contact network voltage to transition stepwise from one power supply arm voltage to the other, eliminating the impact of phase shifting on train operation. This solves the problem of train tripping the main circuit breaker protection caused by large short-term voltage phase changes in traditional switch-switched voltage automatic phase transition schemes. It also solves the problems of high cost and large footprint of inverter voltage phase shifting automatic phase transition schemes.

[0007] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: A live automatic phase-shifting system based on electronic switch voltage phase shifting. It includes a first electronic switch 8, a second electronic switch 9, a third electronic switch 10, a fourth electronic switch 11, N intermediate electronic switches, N≥1, a first transformer 13, a second transformer 14, a ground automatic phase-crossing control unit 16, and several connecting lines; The primary winding of the first transformer 13 is connected between the first power supply arm 1 and the ground. The secondary winding corresponding to the terminal connected to the first power supply arm 1 is connected to the neutral contact network 3 through the first electronic switch 8. The secondary winding corresponding to the terminal connected to the ground is connected to the ground through the second electronic switch 9. The primary winding of the second transformer 14 is connected between the second power supply arm 2 and the ground. The secondary winding corresponding to the terminal connected to the second power supply arm 2 is connected to the neutral contact network 3 through the third electronic switch 10. The secondary winding corresponding to the terminal connected to the ground is connected to the ground through the fourth electronic switch 11. The secondary winding of the first transformer 13 and the secondary winding of the second transformer 14 each have N intermediate taps. Each intermediate tap of the secondary winding of the first transformer 13 is connected to the corresponding intermediate tap of the secondary winding of the second transformer 14 through N intermediate electronic switches. The output voltages of the two transformer secondary windings are added together to obtain multiple intermediate phase-shifting transition voltages.

[0008] A live automatic phase-shifting system based on electronic switch voltage phase shifting. It includes a first electronic switch 8, a second electronic switch 9, a third electronic switch 10, a fourth electronic switch 11, N intermediate electronic switches, N≥3, a first transformer 13, a second transformer 14, a ground automatic phase-crossing control unit 16, and several connecting lines; The first electronic switch 8 and the third electronic switch 10 are connected in series between the first power supply arm 1 and the neutral zone contact network 3. The first power supply arm 1 is connected to the first electronic switch 8, and the neutral zone contact network 3 is connected to the third electronic switch 10. The second electronic switch 9 and the fourth electronic switch 11 are connected in series between the second power supply arm 2 and the neutral zone contact network 3. The second power supply arm 2 is connected to the second electronic switch 9, and the neutral zone contact network 3 is connected to the fourth electronic switch 11. The primary winding of the first transformer 13 is connected between the first power supply arm 1 and ground, and the corresponding terminal of the secondary winding connected to the terminal of the first power supply arm 1 is connected between the first electronic switch 8 and the third electronic switch 10. The primary winding of the second transformer 14 is connected between the second power supply arm 2 and ground, and the corresponding terminal of the secondary winding connected to the terminal of the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11. The secondary windings of the first transformer 13 and the second transformer 14 each have N-1 intermediate taps. Each terminal of the secondary winding of the first transformer 13 is connected to the corresponding terminal of the secondary winding of the second transformer 14 through N intermediate electronic switches. The voltage of the power supply arm is subtracted from the output voltage of one transformer secondary winding and then added to the output voltage of the other transformer secondary winding to obtain multiple intermediate phase-shifting transition voltages.

[0009] A live automatic phase-shifting system based on electronic switch voltage phase shifting. It includes a first electronic switch 8, a second electronic switch 9, a third electronic switch 10, a fourth electronic switch 11, N intermediate electronic switches, N≥0, a first transformer 13, a ground automatic phase-crossing control unit 16, and several connecting lines; The first electronic switch 8 and the third electronic switch 10 are connected in series between the first power supply arm 1 and the neutral zone contact network 3. The first power supply arm 1 is connected to the first electronic switch 8, and the neutral zone contact network 3 is connected to the third electronic switch 10. The second electronic switch 9 and the fourth electronic switch 11 are connected in series between the second power supply arm 2 and the neutral zone contact network 3. The second power supply arm 2 is connected to the second electronic switch 9, and the neutral zone contact network 3 is connected to the fourth electronic switch 11. The two terminals of the primary winding of the first transformer 13 are respectively connected to the first power supply arm 1 and the second power supply arm 2. The corresponding terminal of the secondary winding connected to the terminal of the first power supply arm 1 is connected between the first electronic switch 8 and the third electronic switch 10. The corresponding terminal of the secondary winding connected to the terminal of the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11. The secondary winding of the first transformer 13 has N intermediate taps, which are connected between the third electronic switch 10 and the fourth electronic switch 11 through N intermediate electronic switches. The output voltage of each secondary winding of the first transformer 13 is added to and subtracted from the voltage of the two-phase power supply arm to obtain multiple intermediate phase-shifting transition voltages.

[0010] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is no greater than 60°.

[0011] A live automatic phase-shifting system based on electronic switch voltage phase shifting. In the above scheme, the first transformer 13 uses two transformers, transformer A and transformer B. The primary winding of transformer A is connected between the first power supply arm 1 and ground, and the corresponding secondary winding terminal of the terminal connected to the first power supply arm 1 is connected between the first electronic switch 8 and the third electronic switch 10. The primary winding of transformer B is connected between the second power supply arm 2 and ground, and the corresponding secondary winding terminal of the terminal connected to the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11. The other terminals of the secondary windings of transformer A and transformer B are connected through corresponding electronic switch groups.

[0012] Furthermore, the electronic switch group and the intermediate electronic switch group are each composed of several semiconductor switching valves connected in series, and each semiconductor switching valve has a dynamic and static equalizing impedance connected in parallel across its two ends.

[0013] Furthermore, the semiconductor switching valves of the electronic switch group and the intermediate electronic switch group are composed of reverse resistance type switching devices connected in anti-parallel or reverse conduction type switching devices connected in anti-series.

[0014] Furthermore, the reverse-conducting device is an IGBT with an anti-parallel diode, and the reverse-resistance switching device is a thyristor, GTO, or IGCT.

[0015] The beneficial effects of this invention are: The energized automatic phase-crossing system based on electronic switch voltage phase shifting utilizes a combination of electronic switches and transformers to superimpose AC voltages of different phases and amplitudes into multiple intermediate phase-shifting transition voltages. This allows the neutral zone contact network voltage to gradually switch between the two power supply arms in the neutral zone, reducing the change in voltage phase angle during the neutral zone voltage switching process and achieving a smooth transition of the supply voltage. This eliminates the impact of direct switching of the neutral zone contact network voltage between the two power supply arms when the train passes through the phase-crossing zone on train operation. It integrates the advantages of the switch voltage switching method and the inverter voltage phase shifting method for energized automatic phase-crossing, offering a moderate price, reducing costs, minimizing footprint, and preventing the train from tripping the main circuit breaker protection. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the circuit structure of Embodiment 1 of the present invention; Figure 2 This is a voltage phasor diagram of Embodiment 1 of the present invention; Figure 3 This is a schematic diagram of the circuit structure of Embodiment 2 of the present invention; Figure 4 This is a voltage phasor diagram of Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the circuit structure of Embodiment 1 of Scheme 2 of the present invention; Figure 6 This is a voltage phasor diagram of Embodiment 1 of Scheme 2 of the present invention; Figure 7 These are schematic diagrams of the circuit structures of embodiments two and three of the present invention; Figure 8 This is a voltage phasor diagram of Embodiment 2 of the present invention; Figure 9 This is a voltage phasor diagram of Embodiment 3 of the present invention; Figure 10 This is a schematic diagram of the circuit structure of Embodiment 4 of Scheme 2 of the present invention; Figure 11 This is a voltage phasor diagram of Embodiment 4 of Scheme 2 of the present invention; Figure 12 This is a schematic diagram of the circuit structure of Embodiment 1 of the third scheme of the present invention; Figures 13(a) and 13(b) are schematic diagrams of voltage phasors in Embodiment 1 of the third scheme of the present invention; Figure 14 This is a schematic diagram of the circuit structure of Embodiment 2 of Scheme 3 of the present invention; Figure 15 This is a voltage phasor diagram of Embodiment 2 of Scheme 3 of the present invention; Figure 16 This is a schematic diagram of the circuit structure of Embodiment 3 of the present invention; Figure 17 This is a voltage phasor diagram of Embodiment 3 of the present invention; In the picture: 1: First power supply arm; 2: Second power supply arm; 3: Neutral zone contact wire; 4: Rail; 5: First anchor section joint transition area; 6: Second anchor section joint transition area; 7: Train; 8: First electronic switch; 9: Second electronic switch; 10: Third electronic switch; 11: Fourth electronic switch; 121: First intermediate electronic switch; 122: Second intermediate electronic switch; 123: Third intermediate electronic switch; 124: Fourth intermediate electronic switch; 13: First transformer; 131: First intermediate tap of the secondary winding of the first transformer; 132: Second intermediate tap of the secondary winding of the first transformer; 133: Third intermediate tap of the secondary winding of the first transformer; 14: Second transformer; 141: First intermediate tap of the secondary winding of the second transformer; 142: Second intermediate tap of the secondary winding of the second transformer; 143: Third intermediate tap of the secondary winding of the second transformer; 16: Ground automatic phase transition system control unit; a: First power supply arm voltage; b: Second power supply arm voltage; c: First intermediate phase shift transition voltage; d: Second intermediate phase shift transition voltage; e: Third intermediate phase shift transition voltage; f: Fourth intermediate phase shift transition voltage; g: Fifth intermediate phase shift transition voltage; h: Sixth intermediate phase shift transition voltage. Detailed Implementation

[0017] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0018] This invention utilizes a combination of electronic switches and transformers to perform phasor superposition of AC voltages with different phases and amplitudes to obtain an intermediate phase-shifting transition voltage. This enables the voltage of the neutral zone contact network to gradually shift from one phase power supply arm voltage to another. The intermediate phase-shifting transition voltage is obtained by superimposing the secondary winding voltages of different transformers or by superimposing the secondary winding voltage of the transformer and the power supply arm voltage. Based on different combinations of electronic switches and transformers, this invention provides three solutions.

[0019] The first scheme obtains the intermediate phase-shift transition voltage by adding the output voltages of the secondary windings of the two transformers. The second scheme obtains the intermediate phase-shift transition voltage by subtracting the secondary winding voltage of the transformer connected to ground from the voltage of one phase power supply arm, and then adding the secondary winding voltage of the transformer connected to ground. The third scheme obtains the intermediate phase-shift transition voltage by subtracting or adding the secondary winding voltage of the transformer connected between two phase power supply arms from the voltage of one phase power supply arm. Among these, the third scheme uses the most advantageous transformers and electronic switches, but the amplitude of the obtained intermediate phase-shift transition voltage is smaller than the voltage amplitude of the power supply arm, making it suitable for electrical phase-splitting applications where the phase difference between the two power supply arms is no greater than 60°.

[0020] The three phase-splitting systems presented in this invention comprise an electronic switch group consisting of several semiconductor switching valves connected in series and an intermediate electronic switch group. Each semiconductor switching valve has a dynamic and static voltage-equalizing impedance connected in parallel across its terminals. The dynamic voltage-equalizing impedance consists of a resistor and a capacitor, while the static voltage-equalizing impedance consists solely of a resistor. These dynamic and static voltage-equalizing impedances are connected in parallel across each semiconductor switching valve. The semiconductor switching valves are constructed by anti-parallel connection of reverse-resistance switching devices, preferably thyristors, GTOs, or IGCTs. Alternatively, the semiconductor switching valves can be constructed by anti-series connection of reverse-conducting switching devices, preferably IGBTs with anti-parallel diodes. The semiconductor switching valves achieve bidirectional current flow through the forward and reverse parallel or series connection of the switching devices, and the series connection of the semiconductor switching valves improves the withstand voltage of the electronic switch group and provides redundancy.

[0021] This invention discloses a live automatic phase transition system based on electronic switch voltage phase shifting, comprising: a first electronic switch 8, a second electronic switch 9, a third electronic switch 10, a fourth electronic switch 11, N intermediate electronic switches (N≥1 in scheme 1, N≥3 in scheme 2, N≥0 in scheme 3, depending on the required number of intermediate phase shifting transition voltages), a transformer, a ground automatic phase transition control unit 16, and several connecting lines; the phase transition process also includes a first power supply arm 1, a second power supply arm 2, a neutral zone contact network 3, a rail 4, a first anchor section joint transition area 5, a second anchor section joint transition area 6, and a train 7.

[0022] The ground-based automatic phase control unit 16 controls the opening and closing of each electronic switch through communication methods such as optical fiber.

[0023] When traveling in the forward direction, train 7 moves from the first power supply arm 1 to the second power supply arm 2. When traveling in the reverse direction, train 7 moves from the second power supply arm 2 to the first power supply arm 1. The operation process of each electronic switch and the voltage switching process when the train passes through the phase divider in the reverse direction are symmetrical to the forward process.

[0024] Option 1: The system also includes a first transformer 13 and a second transformer 14. The primary winding of the first transformer 13 is connected between the first power supply arm 1 and ground. The secondary winding corresponding to the terminal connected to the first power supply arm 1 is connected to the neutral zone contact network 3 via a first electronic switch 8. The secondary winding corresponding to the terminal connected to ground is connected to ground via a second electronic switch 9. The primary winding of the second transformer 14 is connected between the second power supply arm 2 and ground. The secondary winding corresponding to the terminal connected to the second power supply arm 2 is connected to the neutral zone contact network 3 via a third electronic switch 10. The secondary winding corresponding to the terminal connected to ground is connected to ground via a fourth electronic switch 11.

[0025] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0026] Both the secondary windings of the first transformer 13 and the second transformer 14 have N intermediate taps; the secondary winding of the first transformer 13 has N intermediate taps. n Middle tap (1≤ n ≤N) through the first n Intermediate electronic switch and the 14th secondary winding of the second transformer n By connecting the intermediate taps, the output voltages of the secondary windings of the two transformers are added together, thus constructing N intermediate phase-shifting transition voltages.

[0027] The primary and secondary winding turns ratios of the first transformer 13 and the second transformer 14 are both 1. The output voltage of each intermediate tap of the secondary winding depends on the amplitude and phase relationship between the corresponding intermediate phase-shifting transition voltage and the voltage of the first power supply arm 1 and the voltage of the second power supply arm 2. The N intermediate phase-shifting transition voltages are usually equal in amplitude to the power supply arm voltage and their phases are evenly distributed between the two power supply arm voltages.

[0028] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit issues a command to open the first electronic switch 8 and the second electronic switch 9, so that the neutral zone contact network 3 carries the voltage of the first power supply arm 1, and train 7 enters the neutral zone with the voltage of the first power supply arm 1. When train 7 reaches the middle of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the first electronic switch 8 and open the third electronic switch 10 and the first intermediate electronic switch, switching the neutral zone contact network voltage to the first intermediate phase-shifting transition voltage; then shut down the first intermediate electronic switch and open the second intermediate electronic switch, switching the neutral zone contact network voltage to the second intermediate phase-shifting transition voltage; next, shut down the second intermediate electronic switch and open the third intermediate electronic switch, switching the neutral zone contact network voltage to the third intermediate phase-shifting transition voltage; and so on, switching according to the same pattern until the neutral zone contact network voltage switches to the Nth intermediate phase-shifting transition voltage; finally, shut down the second electronic switch 9 and the Nth intermediate electronic switch and open the fourth electronic switch 11, switching the neutral zone contact network voltage to the second power supply arm 2 voltage; train 7 continues to move forward with the second power supply arm 2 voltage; When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the third electronic switch 10 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0029] Implementation Example 1 based on Scheme 1: like Figure 1 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121 and a second intermediate electronic switch 122.

[0030] The secondary windings of the first transformer 13 and the second transformer 14 each have two intermediate taps. The first intermediate tap 131 of the secondary winding of the first transformer is connected to the first intermediate tap 141 of the secondary winding of the second transformer through the first intermediate electronic switch 121. The second intermediate tap 132 of the secondary winding of the first transformer is connected to the second intermediate tap 142 of the secondary winding of the second transformer through the second intermediate electronic switch 122.

[0031] The primary-to-secondary winding ratio of the first transformer 13 is 1:1. The voltage between the first intermediate tap 131 of the secondary winding of the first transformer and the corresponding terminal of the secondary winding connected to ground of the primary winding of the first transformer 13 is 0.7422 times the first power supply arm voltage a. The voltage between the second intermediate tap 132 of the secondary winding of the first transformer and the corresponding terminal of the secondary winding connected to ground of the primary winding of the first transformer 13 is 0.3949 times the first power supply arm voltage a.

[0032] The primary-to-secondary winding ratio of the second transformer 14 is 1:1. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.3949 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.7422 times the voltage b of the second power supply arm.

[0033] The first transformer 13 and the second transformer 14 construct two intermediate phase-shifting transition voltages, the amplitude of which is equal to the amplitude of the power supply arm voltage and the phase is evenly distributed between the two phase power supply arm voltages. The phasor diagram is as follows. Figure 2 As shown.

[0034] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1. When train 7 reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase transition control unit 16 issues a command to open the first electronic switch 8 and the second electronic switch 9, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the first electronic switch 8 and turn on the third electronic switch 10 and the first intermediate electronic switch 121, switching the voltage of the neutral zone contact network 3 to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and turn on the second intermediate electronic switch 122, switching the voltage of the neutral zone contact network 3 to the second intermediate phase-shifting transition voltage d; finally shut down the second electronic switch 9 and the second intermediate electronic switch 122 and turn on the fourth electronic switch 11, switching the voltage of the neutral zone contact network 3 to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the third electronic switch 10 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0035] Implementation Example 2 based on Scheme 1: like Figure 3 As shown, the intermediate electronic switch group includes: a first intermediate electronic switch 121, a second intermediate electronic switch 122, and a third intermediate electronic switch 123.

[0036] The secondary windings of the first transformer 13 and the second transformer 14 each have three intermediate taps. The first intermediate tap 131 of the secondary winding of the first transformer 13 is connected to the first intermediate tap 141 of the secondary winding of the second transformer through the first intermediate electronic switch 121. The second intermediate tap 132 of the secondary winding of the first transformer is connected to the second intermediate tap 142 of the secondary winding of the second transformer through the second intermediate electronic switch 122. The third intermediate tap 133 of the secondary winding of the first transformer is connected to the third intermediate tap 143 of the secondary winding of the second transformer through the third intermediate electronic switch 123.

[0037] The primary-to-secondary winding ratio of the first transformer 13 is 1:1. The voltage between the first intermediate tap 131 of the secondary winding of the first transformer 13 and the corresponding terminal of the secondary winding connected to ground of the primary winding of the first transformer 13 is 0.8165 times the first power supply arm voltage a. The voltage between the second intermediate tap 132 of the secondary winding of the first transformer and the corresponding terminal of the secondary winding connected to ground of the primary winding of the first transformer 13 is 0.5774 times the first power supply arm voltage a. The voltage between the third intermediate tap 133 of the secondary winding of the first transformer and the corresponding terminal of the secondary winding connected to ground of the primary winding of the first transformer 13 is 0.2989 times the first power supply arm voltage a.

[0038] The primary-to-secondary winding ratio of the second transformer 14 is 1:1. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.2989 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.5774 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the third intermediate tap 143 of the secondary winding of the second transformer is 0.8165 times the voltage b of the second power supply arm.

[0039] The first transformer 13 and the second transformer 14 construct three intermediate voltages, the amplitude of which is equal to the amplitude of the supply arm voltage and the phase is evenly distributed between the two phase supply arm voltages. The phasor diagram is as follows. Figure 4 As shown.

[0040] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1. When train 7 reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase transition control unit 16 issues a command to open the first electronic switch 8 and the second electronic switch 9, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the first electronic switch 8 and open the third electronic switch 10 and the first intermediate electronic switch 121, switching the voltage of the neutral zone contact network 3 to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the second intermediate electronic switch 122, switching the voltage of the neutral zone contact network 3 to the second intermediate phase-shifting transition voltage d; then shut down the second intermediate electronic switch 122 and open the third intermediate electronic switch 123, switching the voltage of the neutral zone contact network 3 to the third intermediate phase-shifting transition voltage e; finally shut down the second electronic switch 9 and the third intermediate electronic switch 123 and open the fourth electronic switch 11, switching the voltage of the neutral zone contact network 3 to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the third electronic switch 10 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0041] Option 2: The system also includes a first transformer 13 and a second transformer 14. A first electronic switch 8 and a third electronic switch 10 are connected in series between the first power supply arm 1 and the neutral zone contact network 3. The first power supply arm 1 is connected to the first electronic switch 8, and the neutral zone contact network 3 is connected to the third electronic switch 10.

[0042] The second electronic switch 9 and the fourth electronic switch 11 are connected in series between the second power supply arm 2 and the neutral zone contact network 3. The second power supply arm 2 is connected to the second electronic switch 9, and the neutral zone contact network 3 is connected to the fourth electronic switch 11.

[0043] The primary winding of the first transformer 13 is connected between the first power supply arm 1 and ground, and the corresponding secondary winding terminal of the terminal connected to the first power supply arm 1 is connected between the first electronic switch group 8 and the third electronic switch 10. The primary winding of the second transformer 14 is connected between the second power supply arm 2 and ground, and the corresponding secondary winding terminal of the terminal connected to the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11.

[0044] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60° or 90°. The secondary windings of the first transformer 13 and the second transformer 14 each have N-1 intermediate taps. The corresponding secondary winding terminal of the primary winding of the first transformer 13 connected to ground and the N-1 intermediate taps of the secondary winding are connected to the corresponding secondary winding terminal of the primary winding of the second transformer 14 connected to ground and the N-1 intermediate taps of the secondary winding through N intermediate electronic switches. This enables the voltage of the power supply arm to be subtracted from the output voltage of one transformer's secondary winding and then added to the output voltage of the other transformer's secondary winding, thereby constructing N intermediate phase-shifting transition voltages.

[0045] There are two ways to construct the N intermediate phase-shifting transition voltages. The first method involves subtracting the output voltage of the secondary winding of the transformer connected to the first (second) power supply arm from the voltage of that arm, and then adding this result to the output voltage of the secondary winding of the transformer connected to the second (first) power supply arm. The second method involves subtracting the output voltage of the secondary winding of the transformer connected to the first power supply arm from the voltage of that arm, and then adding this result to the output voltage of the secondary winding of the transformer connected to the second power supply arm; and subtracting the output voltage of the secondary winding of the transformer connected to the second power supply arm from the voltage of that arm, and then adding this result to the output voltage of the secondary winding of the transformer connected to the first power supply arm. The first method requires more turns in the secondary winding of the transformer than the second method, therefore the second method is preferred for the intermediate phase-shifting transition voltages.

[0046] The turns ratio of the primary and secondary windings of the first transformer 13 and the second transformer 14 can be either of two different cases depending on the construction method of the intermediate phase-shifting transition voltage. The output voltage of each intermediate tap of the secondary winding depends on the amplitude and phase relationship between each intermediate phase-shifting transition voltage and the voltage of the first power supply arm 1 and the voltage of the second power supply arm 2. The N intermediate phase-shifting transition voltages are usually equal in amplitude to the power supply arm voltage and their phases are evenly distributed between the two phase power supply arm voltages.

[0047] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1. When the train reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase transition control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the voltage of the first power supply arm 1, and train 7 enters the neutral zone carrying the voltage of the first power supply arm 1; Depending on the construction method of the intermediate phase-shifting transition voltage, the voltage switching method of the neutral zone contact network 3 is also divided into two types: (1) When the train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to turn off the third electronic switch 10 and turn on the fourth electronic switch 11 and the first intermediate electronic switch, and the voltage of the neutral zone contact network 3 switches to the first intermediate phase-shifting transition voltage; then the first intermediate electronic switch is turned off and the second intermediate electronic switch is turned on, and the voltage of the neutral zone contact network 3 switches to the second intermediate phase-shifting transition voltage; and so on, switching according to the same rule until the voltage of the neutral zone contact network 3 switches to the Nth intermediate phase-shifting transition voltage; finally the first electronic switch 8 and the Nth intermediate electronic switch are turned off and the second electronic switch 9 is turned on, and the voltage of the neutral zone contact network 3 switches to the voltage of the second power supply arm 2, and the train 7 continues to move forward with the voltage of the second power supply arm 2; (2) When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to turn off the third electronic switch 10 and turn on the fourth electronic switch 11 and the first intermediate electronic switch, and the voltage of the neutral zone contact network 3 switches to the first intermediate phase-shifting transition voltage; then the first intermediate electronic switch is turned off and the second intermediate electronic switch is turned on, and the voltage of the neutral zone contact network 3 switches to the second intermediate phase-shifting transition voltage; and so on, switching according to the same rule until the voltage of the neutral zone contact network 3 switches to the (N+1) / 2 intermediate phase-shifting transition voltage (N is an odd number) or the N / 2 intermediate phase-shifting transition voltage (N is an even number); then the first electronic switch 8, the fourth electronic switch 11 and the (N+1) / 2 intermediate electronic switch (N is an odd number) or the N / 2 intermediate electronic switch (N is an even number) are turned off. The system operates as follows: Activate the second electronic switch 9, the third electronic switch 10, and the (N+3) / 2 intermediate electronic switch (where N is odd) or the N / 2+1 intermediate electronic switch (where N is even). The neutral zone contact network voltage 3 switches to the (N+3) / 2 intermediate phase-shifting transition voltage (where N is odd) or the N / 2+1 intermediate phase-shifting transition voltage (where N is even). Then, disconnect the (N+3) / 2 intermediate electronic switch (where N is odd) or the N / 2+1 intermediate electronic switch (where N is even), and activate the (N+5) / 2 intermediate electronic switch (where N is odd) or the N / 2+2 intermediate electronic switch (where N is even). The neutral zone contact network voltage switches to the (N+5) / 2 intermediate phase-shifting transition voltage (where N is odd) or the N / 2+2 intermediate phase-shifting transition voltage (where N is even). This process continues. The switching continues in the same manner until the voltage of the neutral zone contact network 3 switches to the Nth intermediate phase-shifting transition voltage; finally, the third electronic switch 10 and the Nth intermediate electronic switch are turned off, and the fourth electronic switch 11 is turned on, the voltage of the neutral zone contact network 3 switches to the voltage of the second power supply arm 2, and the train 7 continues to move forward with the voltage of the second power supply arm 2. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0048] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0049] Implementation Example 1 based on Scheme 2: like Figure 5 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121, a second intermediate electronic switch 122, and a third intermediate electronic switch 123.

[0050] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0051] The secondary windings of the first transformer 13 and the second transformer 14 each have two intermediate taps. The first intermediate tap 131 of the secondary winding of the first transformer is connected to the first intermediate tap 141 of the secondary winding of the second transformer through the first intermediate electronic switch 121. The second intermediate tap 132 of the secondary winding of the first transformer is connected to the second intermediate tap 142 of the secondary winding of the second transformer through the second intermediate electronic switch 122. The secondary winding terminal corresponding to the primary winding terminal of the first transformer 13 connected to ground is connected to the secondary winding terminal corresponding to the primary winding terminal of the second transformer 14 connected to ground through the third intermediate electronic switch 123.

[0052] The primary-to-secondary winding ratio of the first transformer 13 is 1:0.7011. The voltage between the corresponding terminal of the secondary winding of the primary winding of the first transformer 13 connected to the terminal of the first power supply arm 1 and the first intermediate tap 131 of the secondary winding of the first transformer is 0.1835 times the voltage a of the first power supply arm. The voltage between the corresponding terminal of the secondary winding of the primary winding of the first transformer 13 connected to the terminal of the first power supply arm 1 and the second intermediate tap 132 of the secondary winding of the first transformer is 0.4226 times the voltage a of the first power supply arm.

[0053] The primary-to-secondary winding ratio of the second transformer 14 is 1:0.8165. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.2989 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.5774 times the voltage b of the second power supply arm.

[0054] The first transformer 13 and the second transformer 14 construct three intermediate phase-shifting transition voltages, the amplitude of which is equal to the amplitude of the power supply arm voltage and the phase is evenly distributed between the two phase power supply arm voltages. The phasor diagram is as follows. Figure 6 As shown.

[0055] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and turn on the fourth electronic switch 11 and the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and turn on the second intermediate electronic switch 122, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; then shut down the second intermediate electronic switch 122 and turn on the third intermediate electronic switch 123, switching the neutral zone contact network 3 voltage to the third intermediate phase-shifting transition voltage e; finally shut down the first electronic switch 8 and the third intermediate electronic switch 123 and turn on the second electronic switch 9, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0056] Implementation Example 2 based on Scheme 2: like Figure 7 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121, a second intermediate electronic switch 122, and a third intermediate electronic switch 123.

[0057] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0058] The secondary windings of the first transformer 13 and the second transformer 14 each have two intermediate taps. The first intermediate tap 131 of the secondary winding of the first transformer is connected to the second intermediate tap 142 of the secondary winding of the second transformer through the first intermediate electronic switch 121. The second intermediate tap 132 of the secondary winding of the first transformer is connected to the first intermediate tap 141 of the secondary winding of the second transformer through the third intermediate electronic switch 123. The secondary winding terminal corresponding to the primary winding terminal of the first transformer 13 connected to ground is connected to the secondary winding terminal corresponding to the primary winding terminal of the second transformer 14 connected to ground through the third intermediate electronic switch 122.

[0059] The primary-to-secondary winding ratio of the first transformer 13 is 1:0.4226. The voltage between the corresponding terminal of the secondary winding of the primary winding of the first transformer 13 connected to the terminal of the first power supply arm 1 and the first intermediate tap 131 of the secondary winding of the first transformer is 0.1835 times the voltage a of the first power supply arm. The voltage between the corresponding terminal of the secondary winding of the primary winding of the first transformer 13 connected to the terminal of the first power supply arm 1 and the second intermediate tap 132 of the secondary winding of the first transformer is 0.2989 times the voltage a of the first power supply arm.

[0060] The primary-to-secondary winding ratio of the second transformer 14 is 1:0.5774. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.1835 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.2989 times the voltage b of the second power supply arm.

[0061] The first transformer 13 and the second transformer 14 construct three intermediate phase-shifting transition voltages, the amplitude of which is equal to the amplitude of the power supply arm voltage and the phase is evenly distributed between the two phase power supply arm voltages. The phasor diagram is as follows. Figure 8 As shown.

[0062] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the fourth electronic switch 11 and the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the second intermediate electronic switch 122, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; then shut down the first electronic switch 8, the fourth electronic switch 11 and the second intermediate electronic switch 122, and open the second electronic switch 9, the third electronic switch 10 and the third intermediate electronic switch 123, switching the neutral zone contact network 3 voltage to the third intermediate phase-shifting transition voltage e; finally shut down the third electronic switch 10 and the third intermediate electronic switch 123, and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0063] Implementation Example 3 based on Scheme 2: The basic structure of Example 3 is the same as that of Example 2, the difference being that... Figure 7 The voltage 'a' of the first power supply arm and the voltage 'b' of the second power supply arm have a 90° phase difference. Therefore, the turns ratios of the first and second transformers are different. The corresponding voltage phasor diagrams are as follows: Figure 9 As shown.

[0064] The primary-to-secondary winding ratio of the first transformer 13 is 1:0.7071. The voltage between the corresponding secondary winding terminal of the primary winding of the first transformer 13 and the first intermediate tap 131 of the secondary winding of the first transformer is 0.0761 times the voltage a of the first power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the first transformer 13 and the second intermediate tap 132 of the secondary winding of the first transformer is 0.3827 times the voltage a of the first power supply arm.

[0065] The primary-to-secondary winding ratio of the second transformer 14 is 1:0.7071. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.0761 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.3827 times the voltage b of the second power supply arm.

[0066] The first transformer 13 and the second transformer 14 construct three intermediate phase-shifting transition voltages, the magnitude of which is equal to the voltage magnitude of the power supply arm and the phase is evenly distributed between the two phase power supply arm voltages.

[0067] Implementation Example 4 based on Scheme 2: like Figure 10 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121, a second intermediate electronic switch 122, a third intermediate electronic switch 123, and a fourth intermediate electronic switch 124.

[0068] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0069] The secondary windings of the first transformer 13 and the second transformer 14 each have three intermediate taps. The first intermediate tap 131 of the secondary winding of the first transformer is connected to the second intermediate tap 142 of the secondary winding of the second transformer through the first intermediate electronic switch 121. The second intermediate tap 132 of the secondary winding of the first transformer is connected to the first intermediate tap 141 of the secondary winding of the second transformer through the fourth intermediate electronic switch 124. The third intermediate tap 133 of the secondary winding of the first transformer is connected to the corresponding secondary winding terminal of the primary winding of the second transformer 14 with the same name as the terminal connected to ground with the primary winding of the first transformer 13 through the third intermediate electronic switch 123.

[0070] The primary-to-secondary winding ratio of the first transformer 13 is 1:0.4697. The voltage between the corresponding secondary winding terminal of the primary winding of the first transformer 13 and the first intermediate tap 131 of the secondary winding of the first transformer is 0.1419 times the voltage a of the first power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the first transformer 13 and the second intermediate tap 132 of the secondary winding of the first transformer is 0.2401 times the voltage a of the first power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the first transformer 13 and the third intermediate tap 133 of the secondary winding of the first transformer is 0.3213 times the voltage a of the first power supply arm.

[0071] The primary-to-secondary winding ratio of the second transformer 14 is 1:0.4697. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the first intermediate tap 141 of the secondary winding of the second transformer is 0.1419 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the second intermediate tap 142 of the secondary winding of the second transformer is 0.2401 times the voltage b of the second power supply arm. The voltage between the corresponding secondary winding terminal of the primary winding of the second transformer 14 and the third intermediate tap 143 of the secondary winding of the second transformer is 0.3213 times the voltage b of the second power supply arm.

[0072] The first transformer 13 and the second transformer 14 construct four intermediate phase-shifting transition voltages, the amplitude of which is equal to the amplitude of the power supply arm voltage and the phase is evenly distributed between the two phase power supply arm voltages. The phasor diagram is as follows. Figure 11 As shown.

[0073] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the fourth electronic switch 11 and the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the second intermediate electronic switch 122, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; then shut down the first electronic switch 8, the fourth electronic switch 11 and the second intermediate electronic switch 122, and open the second electronic switch 9, the third electronic switch 10 and the third intermediate electronic switch 123, switching the neutral zone contact network 3 voltage to the third intermediate phase-shifting transition voltage e; shut down the third intermediate electronic switch 123 and open the fourth intermediate electronic switch 124, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage f; finally shut down the third electronic switch 10 and the fourth intermediate electronic switch 124 and open the second electronic switch 9, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0074] Option 3: The system includes a first transformer 13, a first electronic switch 8 and a third electronic switch 10 connected in series between the first power supply arm 1 and the neutral zone contact network 3. The first power supply arm 1 is connected to the first electronic switch 8, and the neutral zone contact network 3 is connected to the third electronic switch 10.

[0075] The second electronic switch 9 and the fourth electronic switch 11 are connected in series between the second power supply arm 2 and the neutral zone contact network 3. The second power supply arm 2 is connected to the second electronic switch 9, and the neutral zone contact network 3 is connected to the fourth electronic switch 11.

[0076] The two terminals of the primary side of the first transformer 13 are connected to the first power supply arm 1 and the second power supply arm 2 respectively. The corresponding terminal of the secondary winding of the terminal connected to the first power supply arm 1 is connected between the first electronic switch 8 and the third electronic switch 10. The corresponding terminal of the secondary winding of the terminal connected to the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11.

[0077] The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is 60°.

[0078] The secondary winding of the first transformer 13 has N intermediate taps, which are connected between the third electronic switch 10 and the fourth electronic switch 11 through N intermediate electronic switches. This allows the output voltage of each secondary winding of the transformer to be added to and subtracted from the voltage of the two-phase power supply arm, thereby constructing multiple intermediate phase-shifting transition voltages.

[0079] The N intermediate taps of the 13 secondary windings of the first transformer can construct at most 2N+2 intermediate phase-shifting transition voltages; The turns ratio of the primary and secondary windings of the first transformer 13 and the output voltage of each intermediate tap of the secondary winding depend on the phase relationship between the corresponding intermediate phase-shifting transition voltage and the voltage a of the first power supply arm and the voltage b of the second power supply arm; the phasor vertices of the 2N+2 intermediate phase-shifting transition voltages of the transformer are all located on the voltage phasor line of the voltage difference between the two phase power supply arms and are usually evenly distributed on the voltage phasor line.

[0080] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1. When train 7 reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase transition control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the voltage of the first power supply arm 1, and train 7 enters the neutral zone carrying the voltage of the first power supply arm 1; When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the first intermediate electronic switch, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage; then it shuts down the first intermediate electronic switch and opens the second intermediate electronic switch, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage; and so on, switching according to the same pattern until the neutral zone contact network voltage 3 switches to the Nth intermediate phase-shifting transition voltage; then it shuts down the Nth intermediate electronic switch and opens the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the (N+1)th intermediate phase-shifting voltage. The transition voltage is then applied; next, the first electronic switch 8 and the fourth electronic switch 11 are turned off, and the second electronic switch 9 and the third electronic switch 10 are turned on, switching the neutral zone contact network 3 voltage to the (N+2)th intermediate phase-shifting transition voltage; then the third electronic switch 10 is turned off, and the first intermediate electronic switch is turned on, switching the neutral zone contact network 3 voltage to the (N+3)th intermediate phase-shifting transition voltage; then the first intermediate electronic switch is turned off, and the second intermediate electronic switch is turned on, switching the neutral zone contact network 3 voltage to the (N+4)th intermediate phase-shifting transition voltage; and so on, switching according to the same pattern until the neutral zone contact network 3 voltage switches to the 2N+2th intermediate phase-shifting transition voltage. Finally, the Nth intermediate electronic switch is turned off, and the fourth electronic switch 11 is turned on, switching the neutral zone contact network 3 voltage to the second power supply arm 2 voltage; train 7 continues to move forward with the second power supply arm 2 voltage; When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0081] In the above-mentioned scheme three, the first transformer 13 can also be replaced by two transformers, transformer A and transformer B. The primary winding of transformer A is connected between the first power supply arm 1 and ground, and the corresponding secondary winding terminal of the terminal connected to the first power supply arm 1 is connected between the first electronic switch 8 and the third electronic switch 10. The primary winding of transformer B is connected between the second power supply arm 2 and ground, and the corresponding secondary winding terminal of the terminal connected to the second power supply arm 2 is connected between the second electronic switch 9 and the fourth electronic switch 11. The other terminals of the secondary windings of transformer A and transformer B are connected through corresponding electronic switches to achieve the same effect.

[0082] Implementation Example 1 based on Scheme 3: like Figure 12 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121.

[0083] The secondary winding of the first transformer 13 has an intermediate tap that divides the secondary winding of the first transformer 13 into two equal parts and is connected between the third electronic switch 10 and the fourth electronic switch 11 through the first intermediate electronic switch 121, that is, connected to the neutral zone contact network 3.

[0084] The primary-to-secondary winding ratio of the first transformer 13 is 5:2 or 2:1. When the primary-to-secondary winding ratio of the first transformer 13 is 5:2, there are a first intermediate phase-shifting transition voltage c, a second intermediate phase-shifting transition voltage d, a third intermediate phase-shifting transition voltage e, and a fourth intermediate phase-shifting transition voltage f, as shown in the phasor diagram of Figure 13(a). When the primary-to-secondary winding ratio of the first transformer 13 is 2:1, the second intermediate phase-shifting transition voltage d and the third intermediate phase-shifting transition voltage e are equal, which can be regarded as the existence of only the first intermediate phase-shifting transition voltage c, the second intermediate phase-shifting transition voltage d, and the fourth intermediate phase-shifting transition voltage f, as shown in the phasor diagram of Figure 13(b).

[0085] When the primary-to-secondary winding ratio of the first transformer 13 is 5:2: Train 7 starts running on rail 4 and draws power from the first power supply arm 1. When train 7 reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to turn on the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; then shut down the first electronic switch 8 and the fourth electronic switch 11, and open the second electronic switch 9 and the third electronic switch 10, switching the neutral zone contact network 3 voltage to the third intermediate voltage e; next, shut down the third electronic switch 10 and open the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the fourth intermediate phase-shifting transition voltage f; finally, shut down the first intermediate electronic switch 121 and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0086] When the primary-to-secondary winding ratio of the first transformer 13 is 2:1: Train 7 starts running on rail 4 and draws power from the first power supply arm 1. When train 7 reaches the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to turn on the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; then shut down the first electronic switch 8 and the fourth electronic switch 11, and open the second electronic switch 9 and the first intermediate electronic switch 121, switching the neutral zone contact network 3 voltage to the third intermediate phase-shifting transition voltage e; finally shut down the first intermediate electronic switch 121 and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0087] Implementation Example 2 based on Scheme 3: like Figure 14 As shown.

[0088] The primary-to-secondary winding ratio of the first transformer 13 is 3:1 or 2:1. When the primary-to-secondary winding ratio of the first transformer 13 is 3:1, there are two intermediate phase-shifting transition voltages; when the primary-to-secondary winding ratio of the first transformer 13 is 2:1, there is one intermediate phase-shifting transition voltage.

[0089] When the primary-to-secondary winding ratio of the first transformer 13 is 3:1, the voltage phasor diagram is as follows: Figure 15 As shown.

[0090] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut off the third electronic switch 10 and open the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the first intermediate phase-shifting transition voltage c; then it shuts off the first electronic switch 8 and the fourth electronic switch 11, and opens the second electronic switch 9 and the third electronic switch 10, switching the neutral zone contact network 3 voltage to the second intermediate phase-shifting transition voltage d; finally, it shuts off the third electronic switch 10 and opens the fourth electronic switch 11, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0091] Implementation Example 3 based on Scheme 3: like Figure 16 As shown, the intermediate electronic switch group includes a first intermediate electronic switch 121 and a second intermediate electronic switch 122.

[0092] The secondary winding of the first transformer 13 has two intermediate taps. The two intermediate taps divide the secondary winding of the first transformer 13 into three equal parts and connect it to the third electronic switch 10 and the fourth electronic switch 11 through the first intermediate electronic switch 121 and the second intermediate electronic switch 122, respectively, which is connected to the neutral zone contact network 3.

[0093] The primary-to-secondary winding ratio of the first transformer 13 is 7:3 or 2:1. When the primary-to-secondary winding ratio of the first transformer 13 is 7:3, there are six intermediate phase-shifting transition voltages; when the primary-to-secondary winding ratio of the first transformer 13 is 2:1, there are five intermediate phase-shifting transition voltages.

[0094] When the primary-to-secondary winding ratio of the first transformer 13 is 7:3, the voltage phasor diagram is as follows: Figure 17 As shown.

[0095] Train 7 begins to travel on rail 4 and draws power from the first power supply arm 1; when train 7 travels to the first anchor section joint transition area 5 and is about to enter the neutral zone, the ground automatic phase control unit 16 issues a command to open the first electronic switch 8 and the third electronic switch 10, so that the neutral zone contact network 3 carries the first power supply arm voltage a, and train 7 enters the neutral zone with the first power supply arm voltage a. When train 7 reaches the middle position of the neutral zone, the ground automatic phase transition control unit 16 first issues a command to shut down the third electronic switch 10 and open the first intermediate electronic switch 121, switching the voltage of the neutral zone contact network 3 to the first intermediate phase-shifting transition voltage c; then shut down the first intermediate electronic switch 121 and open the second intermediate electronic switch 122, switching the voltage of the neutral zone contact network 3 to the second intermediate phase-shifting transition voltage d; then shut down the second intermediate electronic switch 122 and open the fourth electronic switch 11, switching the voltage of the neutral zone contact network 3 to the third intermediate phase-shifting transition voltage e; finally, shut down the first electronic switch 8 and the fourth electronic switch 11, and open the first intermediate electronic switch 122. The second electronic switch 9 and the third electronic switch 10 switch the neutral zone contact network 3 voltage to the fourth intermediate phase-shifting transition voltage f; then the third electronic switch 10 is turned off and the first intermediate electronic switch 121 is turned on, switching the neutral zone contact network 3 voltage to the fifth intermediate phase-shifting transition voltage g; the first intermediate electronic switch 121 is turned off again and the second intermediate electronic switch 122 is turned on, switching the neutral zone contact network 3 voltage to the sixth intermediate phase-shifting transition voltage h; finally, the second intermediate electronic switch 122 is turned off and the fourth electronic switch 11 is turned on, switching the neutral zone contact network 3 voltage to the second power supply arm voltage b; the train 7 continues to move forward with the second power supply arm voltage b. When train 7 leaves the second anchor section joint transition area 6 and enters the second power supply arm 2 to draw power, the ground automatic phase transition control unit 16 issues a command to shut off the second electronic switch 9 and the fourth electronic switch 11, so that the neutral zone contact network 3 returns to a non-energized state, and train 7 completes the energized phase transition.

[0096] Based on the above three schemes, when train 7 passes through the phase break, the voltage of the neutral zone contact network 3 switches between the voltage of the first power supply arm 1 and the voltage of the second power supply arm 2 multiple times, with the voltage phase changing by a small angle each time.

[0097] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0098] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A live automatic phase-shifting system based on electronic switch voltage phase shifting, characterized in that, It includes a first electronic switch (8), a second electronic switch (9), a third electronic switch (10), a fourth electronic switch (11), N intermediate electronic switches, N≥1, a first transformer (13), a second transformer (14), a ground automatic phase-crossing control unit (16), and several connecting lines; The primary winding of the first transformer (13) is connected between the first power supply arm (1) and the ground. The secondary winding corresponding to the terminal connected to the first power supply arm (1) is connected to the neutral contact network (3) through the first electronic switch (8). The secondary winding corresponding to the terminal connected to the ground is connected to the ground through the second electronic switch (9). The primary winding of the second transformer (14) is connected between the second power supply arm (2) and the ground. The secondary winding corresponding to the terminal connected to the second power supply arm (2) is connected to the neutral contact network (3) through the third electronic switch (10). The secondary winding corresponding to the terminal connected to the ground is connected to the ground through the fourth electronic switch (11). The secondary winding of the first transformer (13) and the secondary winding of the second transformer (14) each have N intermediate taps. Each intermediate tap of the secondary winding of the first transformer (13) is connected to the corresponding intermediate tap of the secondary winding of the second transformer (14) through N intermediate electronic switches. Train (7) starts running on rail (4) and draws power from the first power supply arm (1); when train (7) reaches the first anchor section joint transition area (5) and is about to enter the neutral zone, the ground automatic phase control unit issues an instruction to turn on the first electronic switch (8) and the second electronic switch (9), so that the neutral zone contact network (3) carries the voltage of the first power supply arm (1), and train (7) enters the neutral zone with the voltage of the first power supply arm (1); When the train (7) reaches the middle of the neutral zone, the ground automatic phase transition control unit (16) first issues an instruction to shut down the first electronic switch (8), open the third electronic switch (10) and the first intermediate electronic switch, and switch the neutral zone contact network voltage to the first intermediate phase transition voltage; then shut down the first intermediate electronic switch, open the second intermediate electronic switch, and switch the neutral zone contact network voltage to the second intermediate phase transition voltage; then shut down the second intermediate electronic switch, open the third intermediate electronic switch, and switch the neutral zone contact network (3) voltage to the third intermediate phase transition voltage; switch according to the same rule until the neutral zone contact network voltage switches to the Nth intermediate phase transition voltage; finally shut down the second electronic switch (9) and the Nth intermediate electronic switch, open the fourth electronic switch (11), and switch the neutral zone contact network (3) voltage to the second power supply arm (2) voltage; the train (7) continues to move forward with the second power supply arm (2) voltage; When the train (7) leaves the second anchor section joint transition area (6) and enters the second power supply arm (2) to draw power, the ground automatic phase transition control unit (16) issues a command to shut off the third electronic switch (10) and the fourth electronic switch (11), so that the neutral zone contact network (3) returns to a non-energized state, and the train (7) completes the energized phase transition; The intermediate phase-shifting transition voltage is obtained by adding the output voltages of the secondary winding of the first transformer (13) and the secondary winding of the second transformer (14).

2. A live automatic phase-shifting system based on electronic switch voltage phase shifting, characterized in that, Includes a first electronic switch (8), a second electronic switch (9), a third electronic switch (10), a fourth electronic switch (11), N intermediate electronic switches, N≥3, a first transformer (13), a second transformer (14), a ground automatic phase-crossing control unit (16), and several connecting lines; The first electronic switch (8) and the third electronic switch (10) are connected in series between the first power supply arm (1) and the neutral zone contact network (3). The first power supply arm (1) is connected to the first electronic switch (8), and the neutral zone contact network (3) is connected to the third electronic switch (10). The second electronic switch (9) and the fourth electronic switch (11) are connected in series between the second power supply arm (2) and the neutral zone contact network (3). The second power supply arm (2) is connected to the second electronic switch (9), and the neutral zone contact network (3) is connected to the fourth electronic switch (11). The primary winding of the first transformer (13) is connected between the first power supply arm (1) and the ground, and the secondary winding corresponding to the terminal connected to the first power supply arm (1) is connected between the first electronic switch (8) and the third electronic switch (10). The primary winding of the second transformer (14) is connected between the second power supply arm (2) and the ground, and the secondary winding corresponding to the terminal connected to the second power supply arm (2) is connected between the second electronic switch (9) and the fourth electronic switch (11). The secondary windings of the first transformer (13) and the second transformer (14) each have N-1 intermediate taps. Each terminal of the secondary winding of the first transformer (13) is connected to the corresponding terminal of the secondary winding of the second transformer (14) through N intermediate electronic switches. When the train (7) reaches the middle position of the neutral zone, the ground automatic phase transition control unit (16) first issues an instruction to shut down the third electronic switch (10), open the fourth electronic switch (11) and the first intermediate electronic switch, and switch the neutral zone contact network (3) voltage to the first intermediate phase-shifting transition voltage; then shut down the first intermediate electronic switch, open the second intermediate electronic switch, and switch the neutral zone contact network (3) voltage to the second intermediate phase-shifting transition voltage; and so on, switching according to the same rule until the neutral zone contact network (3) voltage switches to the (N+1) / 2 intermediate phase-shifting transition voltage when N is odd, or the N / 2 intermediate phase-shifting transition voltage when N is even; then shut down the first electronic switch (8), the fourth electronic switch (11) and the (N+1) / 2 intermediate electronic switch when N is odd, or the N / 2 intermediate electronic switch when N is even, and open the second electronic switch (9), the third electronic switch (10) and the (N+3) / 2 intermediate electronic switch when N is odd, or the N / 2 intermediate electronic switch when N is even. When the number of intermediate electronic switches is N / 2+1, the neutral zone contact network voltage (3) switches to the intermediate phase-shifting transition voltage (N+3) / 2 when N is odd or the intermediate phase-shifting transition voltage (N / 2+1) when N is even; then disconnect the intermediate electronic switch (N+3) / 2 when N is odd or the intermediate electronic switch (N / 2+1) when N is even, and open the intermediate electronic switch (N+5) / 2 when N is odd or the intermediate electronic switch (N / 2+2) when N is even, and switch the neutral zone contact network voltage. When N is odd, the intermediate phase-shifting transition voltage is (N+5) / 2, or when N is even, the intermediate phase-shifting transition voltage is N / 2+2. The switching is carried out according to the same rule until the voltage of the neutral zone contact network (3) is switched to the Nth intermediate phase-shifting transition voltage. Finally, the third electronic switch (10) and the Nth intermediate electronic switch are turned off, and the fourth electronic switch (11) is turned on. The voltage of the neutral zone contact network (3) is switched to the voltage of the second power supply arm (2), and the train (7) continues to move forward with the voltage of the second power supply arm (2). When the train (7) leaves the second anchor section joint transition area (6) and enters the second power supply arm (2) to draw power, the ground automatic phase transition control unit (16) issues a command to shut off the second electronic switch (9) and the fourth electronic switch (11), so that the neutral zone contact network (3) returns to a non-energized state, and the train (7) completes the energized phase transition; One part of the intermediate phase-shifting transition voltage is obtained by subtracting the output voltage of the secondary winding of the transformer connected to the first power supply arm from the voltage of the first power supply arm, and then adding it to the output voltage of the secondary winding of the transformer connected to the second power supply arm; the other part of the intermediate phase-shifting transition voltage is obtained by subtracting the output voltage of the secondary winding of the transformer connected to the second power supply arm from the voltage of the second power supply arm, and then adding it to the output voltage of the secondary winding of the transformer connected to the first power supply arm.

3. A live automatic phase-shifting system based on electronic switch voltage phase shifting, characterized in that, It includes a first electronic switch (8), a second electronic switch (9), a third electronic switch (10), a fourth electronic switch (11), N intermediate electronic switches, N≥1, a first transformer (13), a ground automatic phase-crossing control unit (16), and several connecting lines; The first electronic switch (8) and the third electronic switch (10) are connected in series between the first power supply arm (1) and the neutral zone contact network (3). The first power supply arm (1) is connected to the first electronic switch (8), and the neutral zone contact network (3) is connected to the third electronic switch (10). The second electronic switch (9) and the fourth electronic switch (11) are connected in series between the second power supply arm (2) and the neutral zone contact network (3). The second power supply arm (2) is connected to the second electronic switch (9), and the neutral zone contact network (3) is connected to the fourth electronic switch (11). The two terminals of the primary winding of the first transformer (13) are connected to the first power supply arm (1) and the second power supply arm (2) respectively. The terminal of the secondary winding corresponding to the terminal connected to the first power supply arm (1) is connected between the first electronic switch (8) and the third electronic switch (10). The terminal of the secondary winding corresponding to the terminal connected to the second power supply arm (2) is connected between the second electronic switch (9) and the fourth electronic switch (11). The secondary winding of the first transformer (13) has N intermediate taps, which are connected between the third electronic switch (10) and the fourth electronic switch (11) through N intermediate electronic switches respectively; Train (7) starts running on rail (4) and draws power from the first power supply arm (1); when train (7) reaches the first anchor section joint transition area (5) and is about to enter the neutral zone, the ground automatic phase control unit (16) issues an instruction to turn on the first electronic switch (8) and the third electronic switch (10), so that the neutral zone contact network (3) carries the voltage of the first power supply arm (1), and train (7) enters the neutral zone with the voltage of the first power supply arm (1); When the train (7) reaches the middle position of the neutral zone, the ground automatic phase transition control unit (16) first issues a command to shut down the third electronic switch (10) and open the first intermediate electronic switch, switching the voltage of the neutral zone contact network (3) to the first intermediate phase-shifting transition voltage; then shut down the first intermediate electronic switch and open the second intermediate electronic switch, switching the voltage of the neutral zone contact network (3) to the second intermediate phase-shifting transition voltage; the switching is carried out in the same manner until the voltage of the neutral zone contact network (3) switches to the Nth intermediate phase-shifting transition voltage; then shut down the Nth intermediate electronic switch and open the fourth electronic switch (11), switching the voltage of the neutral zone contact network (3) to the N+1th intermediate phase-shifting transition voltage; then shut down the first electronic switch (8) and the fourth electronic switch (11), and open the second electronic switch (9) and The third electronic switch (10) switches the neutral zone contact network (3) voltage to the N+2 intermediate phase-shifting transition voltage; then the third electronic switch (10) is turned off, the first intermediate electronic switch (8) is turned on, and the neutral zone contact network (3) voltage switches to the N+3 intermediate phase-shifting transition voltage; then the first intermediate electronic switch (8) is turned off, the second intermediate electronic switch (9) is turned on, and the neutral zone contact network (3) voltage switches to the N+4 intermediate phase-shifting transition voltage. The switching continues in the same manner until the neutral zone contact network (3) voltage switches to the 2N+2 intermediate phase-shifting transition voltage; finally, the Nth intermediate electronic switch is turned off, the fourth electronic switch (11) is turned on, and the neutral zone contact network (3) voltage switches to the second power supply arm (2) voltage; the train (7) continues to move forward with the second power supply arm (2) voltage. When the train (7) leaves the second anchor section joint switching area (6) and enters the second power supply arm (2) to draw power, the ground automatic phase transition control unit (16) issues a command to shut off the second electronic switch (9) and the fourth electronic switch (11), so that the neutral zone contact network (3) returns to a non-energized state, and the train (7) completes the energized phase transition.

4. The energized automatic phase-crossing system based on electronic switch voltage phase shifting according to claim 3, characterized in that, The phase difference between the voltage a of the first power supply arm and the voltage b of the second power supply arm is no greater than 60°.

5. The energized automatic phase-shifting system based on electronic switch voltage phase shifting according to claim 1, 2, or 3, characterized in that, The electronic switch group and the intermediate electronic switch group are each composed of several semiconductor switching valves connected in series, and each semiconductor switching valve has a dynamic and static equalizing impedance connected in parallel across its two ends.

6. The energized automatic phase-crossing system based on electronic switch voltage phase shifting according to claim 5, characterized in that, The semiconductor switching valves of the electronic switching group and the intermediate electronic switching group are composed of reverse resistance type switching devices connected in anti-parallel or reverse conduction type switching devices connected in anti-series.

7. The energized automatic phase-crossing system based on electronic switch voltage phase shifting according to claim 6, characterized in that, The reverse-conducting switching device is an IGBT with an anti-parallel diode, and the reverse-resistance switching device is a thyristor, GTO, or IGCT.

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