Charging method and device for intermittent tramcar

Abstract

A charging method for an intermittent tramcar, comprising: when a tramcar arrives at a first position, adjusting the bus voltage of a main circuit to U1; when the tramcar arrives at a second position, adjusting the bus voltage of the main circuit to U2, and charging the tramcar; when the tramcar leaves the second position, adjusting the bus voltage of the main circuit to U1 again; and when the tramcar leaves a third position and operates outside a charging section, adjusting the bus voltage of the main circuit to U3, wherein U1 represents a pre-charging voltage, U2 represents an output voltage of a charging cabinet, U3 represents an output voltage of an energy storage unit of the tramcar, and U1>U2>U3. Further provided is a charging device for an intermittent tramcar.

Description

A charging method and device for intermittent tram Technical Field

[0001] The present invention relates to the technical field of trams, and in particular to a charging method and device for an intermittent tram. Background Art

[0002] With the advancement of technology, urban trams are beginning to implement off-grid energy storage throughout their lines. Trains rely on their own energy storage systems while in motion. Upon arrival, they undergo a 30-second rapid recharge to meet the power requirements of the next stop. This mode of operation is also known as intermittent tram operation. Intermittent trams typically use charging rails at stations, which are generally about the same length as the platform, at approximately 30 meters. Upon entering a station, the pantograph rises, contacts the charging rail, and slides onto the platform, waiting for passengers to board and disembark while the train rapidly charges via the charging rails.

[0003] Because the charging rails at the station are always charged, existing intermittent trams must ensure the receiver is in the lowered position before entering the station to avoid arcing caused by a mismatch between the vehicle's bus voltage and the power supply cabinet's output voltage during dynamic contact between the receiver and the charging rail. Once the vehicle has come to a complete stop at the station, the driver must raise the receiver until it contacts the rail before charging can begin. Once charging is complete, the driver lowers the receiver until it is free from the rail.

[0004] However, the inventors of this application have discovered that the above technology has at least the following technical problems: the entire process requires manual control and the operation is cumbersome, which not only affects the charging efficiency, but the frequent raising and lowering of the bow will also affect the service life of the receiver. It may even be possible that the vehicle fails to complete charging or arcing occurs between the receiver and the charging rail due to the driver's negligence.

[0005] Summary of the Invention

[0006] The present application provides a method and device for charging an intermittent tram to solve at least one of the above technical problems. To achieve the above objectives, the present application adopts the following technical solutions.

[0007] In one aspect, a method for charging an intermittent tram is provided, the method comprising:

[0008] When the tram arrives at the first position, the main circuit bus voltage of the tram is adjusted to U1;

[0009] When the tram arrives at the second position, the main circuit bus voltage of the tram is adjusted to U2 and charging is performed;

[0010] When the tram leaves the second position, the main circuit bus voltage of the tram is adjusted to U1 again;

[0011] When the tram leaves the third position and runs outside the charging zone, the main circuit bus voltage of the tram is adjusted to U3;

[0012] Among them, the first position, the second position, and the third position are set in sequence in the direction of travel of the tram, and the charging interval is the interval between the first position and the third position; the first position is the end of the charging rail close to the direction of entry into the station, the second position is the charging position of the tram, and the third position is the end of the charging rail away from the direction of entry into the station; U1 is the pre-charging voltage, U2 is the output voltage of the charging cabinet, and U3 is the output voltage of the energy storage unit of the tram, U1>U2>U3.

[0013] This method allows the current receiver to remain in a constant raised state during vehicle operation and charging, eliminating the need for frequent raising and lowering movements. This increases its service life, reduces driver effort, and improves charging efficiency. Furthermore, by raising the tram's main circuit bus voltage to a level higher than the charging cabinet's output voltage before the current receiver makes contact with the charging rail, arcing between the current receiver and the charging rail can be effectively avoided.

[0014] In another aspect, a charging device for an intermittent tram is provided, comprising:

[0015] a position acquisition unit for acquiring the real-time position of the tram; and

[0016] Control unit for:

[0017] When the tram arrives at the first position, the main circuit bus voltage of the tram is adjusted to U1;

[0018] When the tram arrives at the second position, the main circuit bus voltage of the tram is adjusted to U2 and the tram is charged; when the tram leaves the second position, the main circuit bus voltage of the tram is adjusted to U1 again;

[0019] When the tram leaves the third position and runs outside the charging interval, the main circuit bus voltage of the tram is adjusted to U3; wherein the first position, the second position, and the third position are arranged sequentially in the direction of travel of the tram, and the charging interval is the interval between the first position and the third position; the first position is the end of the charging rail close to the direction of entry into the station, the second position is the charging position of the tram, and the third position is the end of the charging rail away from the direction of entry into the station; U1 is the pre-charging voltage, U2 is the output voltage of the charging cabinet, and U3 is the output voltage of the energy storage unit of the tram, U1>U2>U3.

[0020] This device allows the current receiver to remain in a constant raised state during vehicle operation and charging, eliminating the need for frequent raising and lowering movements. This increases its service life, reduces driver effort, and improves charging efficiency. Furthermore, by raising the tram's main circuit bus voltage to a level higher than the charging cabinet's output voltage before the current receiver makes contact with the charging rail, arcing between the current receiver and the charging rail can be effectively avoided.

[0021] To implement hard-wired control, in some embodiments, the control unit includes a power control unit, a signal host, a travel switch, a first relay, and a second relay;

[0022] One end of the travel switch is electrically connected to the positive pole of the busbar, and the other end is electrically connected to the negative pole of the busbar through the coil end of the first relay;

[0023] One end of the signal host is electrically connected to the positive pole of the busbar, and the other end is electrically connected to the negative pole of the busbar through the coil end of the second relay;

[0024] The first input terminal of the power control unit is electrically connected to the positive electrode of the busbar through the normally open contact of the second relay, and the second input terminal is electrically connected between the first input terminal of the power control unit and the normally open contact of the second relay through the normally closed contact of the first relay;

[0025] The signal host is configured to: send a low level to the coil end of the second relay when the tram leaves the third position and runs outside the charging zone, and send a high level to the coil end of the second relay when the tram reaches the first position; the limit switch is opened when the driver controller handle returns to the traction position, and is closed when the driver controller handle returns to the traction position;

[0026] When the first input terminal of the power control unit collects a low-level signal, it adjusts the main circuit bus voltage of the tram to U3;

[0027] When the first input terminal of the power control unit collects a high level signal and the second input terminal of the power control unit collects a low level signal, the main circuit bus voltage of the tram is adjusted to U1;

[0028] When the second input terminal collects a high-level signal, the main circuit bus voltage of the tram is adjusted to U2.

[0029] To ensure charging safety, some embodiments further include a brake control unit and a third relay. One end of the brake control unit is electrically connected to the positive pole of the busbar, and the other end is electrically connected to the negative pole of the busbar via the coil end of the third relay. The normally closed contact of the third relay is connected in series with the normally closed contact of the first relay. The brake control unit is configured to send a low-level signal to the coil end of the third relay when the tram speed reaches zero. This ensures that charging can only be performed when the vehicle speed is zero.

[0030] To achieve network control, in some embodiments, the control unit further includes a train control host, the train control host having a first signal acquisition unit, a second signal acquisition unit, and a third signal acquisition unit, the first signal acquisition unit being connected in parallel with the coil end of the first relay, the second signal acquisition unit being connected in parallel with the coil end of the second relay, and the third signal acquisition unit being connected in parallel with the coil end of the third relay; the output end of the train control host being electrically connected to the third input end of the power control unit;

[0031] The train control host is configured as follows:

[0032] When the tram is in the charging zone and the first and third signal acquisition units both detect a low level, a first signal is sent to the power control unit, and when the second signal acquisition unit detects a low level, a second signal is sent to the power control unit;

[0033] When the tram is in the charging section and the third signal acquisition unit acquires a high level, or when the tram is in the charging section and the third signal acquisition unit acquires a low level but the first signal acquisition unit acquires a high level, a third signal is sent to the power control unit;

[0034] The power control unit is further configured to adjust the tram's main circuit bus voltage to U2 upon receiving a first signal, to U3 upon receiving a second signal, and to U1 upon receiving a third signal. This creates redundancy between network control and hardwired control, improving the reliability of charging control. To further enhance charging control reliability, in some embodiments, two control units are provided, each redundant.

[0035] To achieve vehicle positioning, in some embodiments, the position acquisition unit includes a beacon antenna and a positioning coil, the beacon antenna is located at the bottom of the tram; there are multiple positioning coils, which are respectively located on the tracks corresponding to the first position, the second position and the third position.

[0036] Furthermore, a diode is provided between the main circuit bus of the tram and the output end of the charging cabinet, and the anode and cathode of the diode are respectively located on a side close to the output end of the charging cabinet and a side away from the output end of the charging cabinet.

[0037] This application has at least the following technical effects or advantages:

[0038] 1. The charger can be kept in a constant rising state during vehicle operation and charging, without the need for frequent lifting and lowering actions, thereby increasing its service life, reducing driver operations, and improving charging efficiency.

[0039] 2. By raising the main circuit bus voltage of the tram to a level higher than the output voltage of the charging cabinet before the receiver contacts the charging rail, arcing between the receiver and the charging rail can be effectively avoided.

[0040] 3. Network control and hard-wire control form redundancy, which improves the reliability of charging control. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a schematic diagram of a charging process of an intermittent tram in one embodiment of the present application;

[0042] FIG2 is a schematic diagram of the circuit structure of a hard-wired control device in one embodiment of the present application;

[0043] FIG3 is a schematic diagram of the circuit structure of a network control device in an embodiment of the present application. DETAILED DESCRIPTION

[0044] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods.

[0045] Example 1

[0046] A method for charging an intermittent tram, the method comprising:

[0047] When the tram arrives at the first position B, the main circuit bus voltage of the tram is adjusted to U1;

[0048] When the tram arrives at the second position C, the main circuit bus voltage of the tram is adjusted to U2 and charging is performed;

[0049] When the tram leaves the second position C, the main circuit bus voltage of the tram is adjusted to U1 again;

[0050] When the tram leaves the third position D and runs outside the charging zone, the main circuit bus voltage of the tram is adjusted to U3;

[0051] The first position B is the end of the charging rail closest to the station entrance, the second position C is the charging position of tram 1, and the third position D is the end of the charging rail away from the station entrance. U1 is the pre-charge voltage, U2 is the output voltage of the charging cabinet, and U3 is the output voltage of the tram's energy storage unit. U1>U2>U3. The first position B, second position C, and third position D are set in sequence in the direction of travel of tram 1. The charging range is the interval between the first position B and the third position D.

[0052] As shown in FIG1 , a tram 1 enters the station from direction A to direction E for charging.

[0053] When the tram 1 reaches the first position B (the end of the charging rail 2 closest to the station entrance), the receiver is about to come into contact with the charging rail, adjusting the tram's main circuit bus voltage to the pre-charge voltage U1. Because the pre-charge voltage U1 is higher than the output voltage U2 of the charging cabinet 3, arcing between the receiver and the charging rail 2 is effectively avoided.

[0054] When the tram 1 reaches the second position C (charging position), the main circuit bus voltage of the tram 1 is adjusted to the output voltage U2 of the charging cabinet 3 and charging is carried out. The on and off of the charging circuit can be controlled by the output contactor K1 of the charging cabinet 3. The diode V1 is used to prevent the electric energy of the energy storage power supply from flowing back to the charging cabinet 3 when the main circuit bus voltage of the vehicle is higher than the voltage of the charging cabinet 3.

[0055] When charging is completed and the tram 1 leaves the second position C (charging position), the main circuit bus voltage of the tram 1 is adjusted to U1 again to avoid arcing between the receiver and the charging rail when the receiver is separated from the charging rail.

[0056] When the tram 1 leaves the third position D (the end of the charging rail 2 away from the station approach direction) and runs outside the charging range (A and E), the main circuit bus voltage of the tram 1 is adjusted to the output voltage U3 of the energy storage unit.

[0057] Example 2

[0058] A charging device for an intermittent tram, comprising:

[0059] a position acquisition unit for acquiring the real-time position of the tram; and

[0060] Control unit for:

[0061] When the tram arrives at the first position B, the main circuit bus voltage of the tram is adjusted to U1;

[0062] When the tram arrives at the second position C, the main circuit bus voltage of the tram is adjusted to U2 and charging is performed;

[0063] When the tram leaves the second position C, the main circuit bus voltage of the tram is adjusted to U1 again;

[0064] When the tram leaves the third position D and runs outside the charging zone, the main circuit bus voltage of the tram is adjusted to U3;

[0065] The first position B is the end of the charging rail closest to the station entrance, the second position C is the charging position of tram 1, and the third position D is the end of the charging rail away from the station entrance. U1 is the pre-charge voltage, U2 is the output voltage of the charging cabinet, and U3 is the output voltage of the tram's energy storage unit. U1>U2>U3. The first position B, second position C, and third position D are set in sequence in the direction of travel of tram 1. The charging range is the interval between the first position B and the third position D.

[0066] The position acquisition unit may include a beacon antenna and a positioning coil. The beacon antenna is located at the bottom of the tram. Multiple positioning coils are provided and are located on the tram track 4 corresponding to the first position B, the second position C, and the third position D. The position acquisition unit may also adopt other existing methods or devices for obtaining the position of a rail vehicle, such as an electronic tag + card reader.

[0067] The main circuit bus voltage of the tram can be adjusted by a DC / DC device, one end of the DC / DC device is electrically connected to the output end of the energy storage unit of the tram, and the other end is electrically connected to the main circuit bus.

[0068] The control unit can be a hard-wired control device, a network control device, or a combination of the two. As shown in FIG2 , this embodiment provides a control unit that combines hard-wired and network control and is mutually redundant, as follows:

[0069] The hard-wired control device includes a power control unit 101, a signal host 103, a limit switch 104, a brake control unit 102, a first relay, a second relay and a third relay; the limit switch 104 is the limit switch 104 of the controller and is a normally open contact. One end of the travel switch 104 is electrically connected to the positive busbar, and the other end is electrically connected to the negative busbar via the coil terminal KM1 of the first relay. One end of the signal host 103 is electrically connected to the positive busbar, and the other end is electrically connected to the negative busbar via the coil terminal KM2 of the second relay. One end of the brake control unit 102 is electrically connected to the positive busbar, and the other end is electrically connected to the negative busbar via the coil terminal KM3 of the third relay. The first input terminal 11 of the power control unit 101 is electrically connected to the positive busbar via the normally open contact KM21 of the second relay, and the second input terminal 12 is electrically connected between the first input terminal 11 of the power control unit 101 and the normally open contact KM21 of the second relay, respectively, via the normally closed contact KM11 of the first relay and the normally closed contact KM31 of the third relay. Terminal 13 is the power input terminal for the power control unit 101.

[0070] The signal host 103 sends a low level to the coil end of the second relay when the tram leaves the third position D and runs outside the charging zone, and sends a high level to the coil end of the second relay when the tram reaches the first position B;

[0071] The limit switch 104 is disconnected when the driver controller handle returns to the traction position, and is closed when the driver controller handle is in the traction position;

[0072] The brake control unit 102 sends a low level signal to the coil end of the third relay when the vehicle speed is zero;

[0073] The first input end of the power supply control unit 101 adjusts the main circuit bus voltage of the tram to U3 when a low-level signal is collected; the second input end of the power supply control unit 101 adjusts the main circuit bus voltage of the tram to U1 when a low-level signal is collected, and adjusts the main circuit bus voltage of the tram to U2 when a high-level signal is collected.

[0074] When the vehicle is running outside the charging station area (A or E), the signal host 103 outputs a low level to the coil terminal KM2 of the second relay, so that its normally open contact KM21 remains disconnected. The first input terminal 11 of the power control unit 101 collects the low level signal and adjusts the main circuit bus voltage of the tram to U3.

[0075] When the vehicle reaches position B from position A, the signal host 103 continuously sends a high-level signal to the coil terminal KM2 of the second relay, closing its normally open contact KM21. The control power supply then inputs the high-level signal to the first input terminal 11 of the power control unit 101 via this contact. Since the vehicle is still at a non-zero speed, the brake control unit 102, based on the speed signal collected by the speed sensor, continuously outputs a high-level signal to the coil terminal KM3 of the third relay, opening its normally closed contact KM31. The second input terminal 12 of the power control unit 101 collects a low-level signal and adjusts the tram's main circuit bus voltage to U1. When the vehicle reaches position C from position B, it stops, the driver's handle returns to its original position, the normally open contact of its travel switch 104 opens, and the coil terminal KM1 of the first relay loses power, closing its normally closed contact KM11. The braking control unit 102 outputs a low-level signal to the coil terminal KM3 of the third relay based on the zero-speed signal collected by the speed sensor, closing its normally closed contact KM31. The control power supply inputs a high-level signal to the second input terminal 12 of the power control unit 101 through the normally open contact KM21 of the second relay, the normally closed contact KM11 of the first relay, and the normally closed contact KM31 of the third relay, and adjusts the main circuit bus voltage of the tram to U2.

[0076] When the vehicle is fully charged and leaves position C, the driver operates the driver controller handle at the occupying end to the traction position, the normally open contact of its travel switch 104 is closed, the coil end KM1 of the first relay is energized, and its normally closed contact KM11 is disconnected. The second input end 12 of the power control unit 101 collects a low-level signal and adjusts the main circuit bus voltage of the tram to U1.

[0077] When the vehicle leaves position D, the signal host 103 outputs a low-level signal to the coil terminal KM2 of the second relay, disconnecting its normally open contact KM21. At this time, the first input terminal 11 of the power control unit 101 collects the low-level signal and adjusts the main circuit bus voltage of the tram to U3.

[0078] As shown in FIG3 , the network control device includes a train control host 105, which includes a first signal acquisition unit 101, a second signal acquisition unit 102, and a third signal acquisition unit 103. The first signal acquisition unit 101 is connected in parallel to the coil terminal KM1 of the first relay, the second signal acquisition unit is connected in parallel to the coil terminal KM2 of the second relay, and the third signal acquisition unit is connected in parallel to the coil terminal KM3 of the third relay. The output terminal of the train control host 105 is electrically connected to the third input terminal of the power control unit 101.

[0079] The train control host 105 sends a first signal to the power control unit 101 when the first signal acquisition unit IO1 and the third signal acquisition unit IO3 both collect a low level, sends a second signal to the power control unit 101 when the second signal acquisition unit IO2 collects a low level, and sends a third signal to the power control unit 101 when the third signal acquisition unit IO3 collects a high level, or when the third signal acquisition unit IO3 collects a low level but the first signal acquisition unit IO1 collects a high level.

[0080] The power control unit 101 adjusts the main circuit bus voltage of the tram to U2 when receiving the first signal, adjusts the main circuit bus voltage of the tram to U3 when receiving the second signal, and adjusts the main circuit bus voltage of the tram to U1 when receiving the third signal.

[0081] When the vehicle is running outside the charging station zone (A or E), the signal host 103 sends a low-level signal to the second signal acquisition unit IO2, and the power control unit 101 adjusts the main circuit bus voltage of the tram to U3.

[0082] When the vehicle enters the charging station zone (BD), the signal host 103 sends a high-level signal to the second signal acquisition unit 102. When the driver places the traction handle in the 0 position, the first signal acquisition unit 101 acquires a low-level signal. When the driver operates the driver controller handle on the occupied end to the traction position, the first signal acquisition unit 101 acquires a high-level signal. When the speed sensor transmits a zero-speed signal to the brake control unit 102, the third signal acquisition unit 103 acquires a low-level signal. When the speed sensor transmits a non-zero-speed signal to the brake control unit 102, the third signal acquisition unit 103 acquires a high-level signal.

[0083] When the vehicle enters the charging station zone (BD):

[0084] 1. If the vehicle is at a non-zero speed, that is, the third signal acquisition unit IO3 acquires a high level, the train control host 105 sends a third signal to the power control unit 101, and the power control unit 101 adjusts the main circuit bus voltage of the tram to U1.

[0085] 2. If the vehicle is at zero speed and there is no traction command, that is, the third signal acquisition unit IO3 collects a low level and the first signal acquisition unit IO1 collects a low level, then the train control host 105 sends a first signal to the power control unit 101, and the power control unit 101 adjusts the main circuit bus voltage of the tram to U2.

[0086] 3. If the vehicle is at zero speed but there is a traction command, that is, the third signal acquisition unit IO3 collects a low level and the first signal acquisition unit IO1 collects a high level, then the train control host 105 sends a third signal to the power control unit 101, and the power control unit 101 adjusts the main circuit bus voltage of the tram to U1.

[0087] Furthermore, in addition to the redundancy between the hard line and the network control device, two redundant control units can also be provided.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for charging an intermittent tram, the method comprising: When the tram (1) reaches the first position (B), the main circuit bus voltage of the tram (1) is adjusted to U1; When the tram (1) reaches the second position (C), the main circuit bus voltage of the tram (1) is adjusted to U2 and the tram (1) is charged; When the tram (1) leaves the second position (C), the main circuit bus voltage of the tram (1) is adjusted to U1 again; When the tram (1) leaves the third position (D) and runs outside the charging zone, the main circuit bus voltage of the tram (1) is adjusted to U3; The first position (B) is the end of the charging rail (2) close to the direction of entering the station, the second position (C) is the charging position of the tram (1), and the third position (D) is the end of the charging rail (2) away from the direction of entering the station; U1 is the pre-charging voltage, U2 is the output voltage of the charging cabinet (3), and U3 is the output voltage of the energy storage unit of the tram (1), and U1>U2>U3.

2. A charging device for an intermittent tram, characterized in that: include: A position acquisition unit, used for acquiring the real-time position of the tram (1); and Control unit for: When the tram (1) reaches the first position (B), the main circuit bus voltage of the tram (1) is adjusted to U1; When the tram (1) reaches the second position (C), the main circuit bus voltage of the tram (1) is adjusted to U2 and the tram (1) is charged; When the tram (1) leaves the second position (C), the main circuit bus voltage of the tram (1) is adjusted to U1 again; When the tram (1) leaves the third position (D) and runs outside the charging zone, the main circuit bus voltage of the tram (1) is adjusted to U3; The first position (B) is the end of the charging rail (2) close to the direction of entering the station, the second position (C) is the charging position of the tram (1), and the third position (D) is the end of the charging rail (2) away from the direction of entering the station; U1 is the pre-charging voltage, U2 is the output voltage of the charging cabinet (3), and U3 is the output voltage of the energy storage unit of the tram (1), and U1>U2>U3.

3. The intermittent tram charging device according to claim 2, characterized in that: The control unit comprises a power control unit (101), a signal host (103), a travel switch (104), a first relay and a second relay; One end of the travel switch (104) is electrically connected to the positive pole of the busbar, and the other end is electrically connected to the negative pole of the busbar through the coil end (KM1) of the first relay; One end of the signal host (103) is electrically connected to the positive pole of the busbar, and the other end is electrically connected to the negative pole of the busbar through the coil end (KM2) of the second relay; The first input end (11) of the power control unit (101) is electrically connected to the positive pole of the busbar via the normally open contact (KM21) of the second relay, and the second input end (12) of the power control unit (101) is electrically connected between the first input end (11) of the power control unit (101) and the normally open contact (KM21) of the second relay via the normally closed contact (KM11) of the first relay; The signal host (103) is configured to: send a low level to the coil end (KM2) of the second relay when the tram (1) leaves the third position (D) and runs outside the charging zone, and send a high level to the coil end (KM2) of the second relay when the tram (1) reaches the first position (B); The travel switch (104) is configured to be disconnected when the driver controller handle returns to the traction position, and closed when the driver controller handle reaches the traction position; When the first input terminal (11) of the power control unit (101) collects a low-level signal, the main circuit bus voltage of the tram (1) is adjusted to U3; When the first input terminal (11) of the power control unit (101) collects a high-level signal and the second input terminal (12) of the power control unit (101) collects a low-level signal, the main circuit bus voltage of the tram (1) is adjusted to U1; When the second input terminal (12) collects a high-level signal, the main circuit bus voltage of the tram (1) is adjusted to U2.

4. The intermittent tram charging device according to claim 3, characterized in that: The invention also comprises a braking control unit (102) and a third relay; one end of the braking control unit (102) is electrically connected to the positive pole of the bus, and the other end is electrically connected to the negative pole of the bus through the coil end (KM3) of the third relay; the normally closed contact (KM31) of the third relay is connected in series with the normally closed contact (KM11) of the first relay; the braking control unit (102) is configured to send a low-level signal to the coil end (KM3) of the third relay when the speed of the tram (1) is zero.

5. The intermittent tram charging device according to claim 4, characterized in that: The control unit further comprises a train control host (105), the train control host (105) comprising a first signal acquisition unit (IO1), a second signal acquisition unit (IO2) and a third signal acquisition unit (IO3), the first signal acquisition unit (IO1) being connected in parallel with the coil end (KM1) of the first relay, the second signal acquisition unit (IO2) being connected in parallel with the coil end (KM2) of the second relay, and the third signal acquisition unit (IO3) being connected in parallel with the coil end (KM3) of the third relay; the output end of the train control host (105) being electrically connected to the third input end of the power control unit (101); The train control host (105) is configured as follows: When the tram (1) is located in the charging zone and the first signal acquisition unit (IO1) and the third signal acquisition unit (IO3) both acquire a low level, a first signal is sent to the power supply control unit (101); When the second signal acquisition unit (IO2) acquires a low level, sending a second signal to the power control unit (101); When the tram (1) is located in the charging section and the third signal acquisition unit (IO3) acquires a high level, or when the tram (1) is located in the charging section and the third signal acquisition unit (IO3) acquires a low level and the first signal acquisition unit (IO1) acquires a high level, a third signal is sent to the power control unit (101); The power control unit (101) is further configured to: adjust the main circuit bus voltage of the tram (1) to U2 when receiving the first signal, adjust the main circuit bus voltage of the tram (1) to U3 when receiving the second signal, and adjust the main circuit bus voltage of the tram (1) to U1 when receiving the third signal.

6. The intermittent tram charging device according to any one of claims 2 to 5, characterized in that: There are two control units, and the two control units are redundant with each other.

7. The intermittent tram charging device according to any one of claims 2 to 5, characterized in that: The position acquisition unit comprises a beacon antenna and a positioning coil, wherein the beacon antenna is located at the bottom of the tram (1); a plurality of positioning coils are provided, which are respectively located on the tram track (4) corresponding to the first position (B), the second position (C) and the third position (D).

8. The intermittent tram charging device according to any one of claims 2 to 5, characterized in that: A diode (V1) is provided between the main circuit busbar of the tram (1) and the output end of the charging cabinet (3), and the anode and cathode of the diode (V1) are respectively located on a side close to the output end of the charging cabinet (3) and a side far from the output end of the charging cabinet (3).

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