A charging method and device for an intermittent tram

Abstract

The application discloses a charging method and device for an intermittent tram, comprising: when the tram reaches a first position, adjusting the main circuit bus voltage of the tram to U1; when the tram reaches a second position, adjusting the main circuit bus voltage of the tram to U2 and charging; when the tram drives away from the second position, adjusting the main circuit bus voltage of the tram to U1 again; when the tram drives away from a third position and runs outside the charging area, adjusting the main circuit bus voltage of the tram to U3. Compared with the prior art, the application enables the power receiver to be in a constant rising state during the tram running and charging process, and frequent rising and falling actions are not needed, so that the service life of the power receiver is improved, the driver operation is reduced, and the charging efficiency is improved. On the other hand, the application can effectively avoid the situation that an arc is generated between the power receiver and the charging rail.

Description

Technical Field

[0001] This invention relates to the field of tram technology, and more specifically to a charging method and apparatus for intermittent trams. Background Technology

[0002] With the development of technology, urban trams have begun to implement grid-free energy storage across the entire line. Trains operate using their own energy storage systems while in motion, and upon arrival at a station, they undergo a rapid 30-second recharge to meet the power requirements for operation at the next station. This operating mode is also known as intermittent tram operation. Generally, intermittent trams use charging rails for station charging, with the length of the charging rail typically comparable to the platform length, approximately 30 meters. After the train enters the station, the pantograph rises, contacts the charging rail, and then slides into the platform to await passenger boarding and alighting, while simultaneously undergoing rapid recharging via the charging rail.

[0003] Because the charging rails at the platform are always energized, existing intermittent trams, when entering the station for charging, must ensure the pantograph is in a lowered position before the vehicle enters the station to prevent arcing due to voltage mismatch between the vehicle's busbar and the power supply cabinet during dynamic contact between the pantograph and the charging rail. Once the vehicle has come to a complete stop at the platform, the driver must raise the pantograph to contact the charging rail before charging can begin. After charging is complete, the driver must lower the pantograph again to detach it from the charging rail.

[0004] However, the inventors of this application have discovered that the above-mentioned technology has at least the following technical problems: the whole process requires manual control, which is cumbersome to operate. This not only affects the charging efficiency, but also the frequent raising and lowering of the pantograph will affect the service life of the receiver. It may even cause the vehicle to fail to complete charging or the receiver to arc with the charging rail due to the driver's negligence. Summary of the Invention

[0005] This application provides a charging method and apparatus for intermittent trams to solve at least one of the above-mentioned technical problems.

[0006] To achieve the above objectives, this application adopts the following technical solution.

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

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

[0009] When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it is charged.

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

[0011] When the tram leaves the third position and is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3.

[0012] Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

[0013] The above method allows the receiver to remain in a constantly raised state during vehicle operation and charging, eliminating the need for frequent raising and lowering operations, thereby extending its service life, reducing driver intervention, and improving charging efficiency. Furthermore, 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 prevented.

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

[0015] A location acquisition unit is used to acquire the real-time location of the tram; and

[0016] Control unit, used for:

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

[0018] When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it 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 is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3.

[0020] Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

[0021] The aforementioned device allows the power receiver to remain in a constantly raised state during vehicle operation and charging, eliminating the need for frequent raising and lowering operations. This extends its service life, reduces driver intervention, and improves charging efficiency. Furthermore, by raising the main circuit bus voltage of the tram to a level higher than the output voltage of the charging cabinet before the power receiver contacts the charging rail, arcing between the power receiver and the charging rail can be effectively prevented.

[0022] To achieve hard-wired control, in some embodiments, the control unit includes a power control unit, a signal host, a limit switch, a first relay, and a second relay;

[0023] One end of the limit switch is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal of the first relay;

[0024] One end of the signal host is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal of the second relay;

[0025] The first input terminal of the power control unit is electrically connected to the positive terminal of the bus 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.

[0026] The signal host sends a low level to the coil terminal of the second relay when the tram leaves the third position and is running outside the charging zone, and sends a high level to the coil terminal of the second relay when the tram arrives at the first position.

[0027] The limit switch is open when the driver's handle returns to the original position and closed when the driver's handle is moved to the traction position.

[0028] When a low-level signal is detected, the first input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U3.

[0029] When a low-level signal is received, the second input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U1, and when a high-level signal is received, it adjusts the main circuit bus voltage of the tram to U2.

[0030] To ensure charging safety, some embodiments further include a braking control unit and a third relay. One end of the braking control unit is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal 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 braking control unit sends a low-level signal to the coil terminal of the third relay when the vehicle speed is zero. This ensures that charging can only occur when the vehicle speed is zero.

[0031] To achieve network control, in some embodiments, the control unit further includes a train control host, which has a first signal acquisition unit, a second signal acquisition unit, and a third signal acquisition unit. The first signal acquisition unit is connected in parallel with the coil terminal of the first relay, the second signal acquisition unit is connected in parallel with the coil terminal of the second relay, and the third signal acquisition unit is connected in parallel with the coil terminal of the third relay. The output terminal of the train control host is electrically connected to the third input terminal of the power control unit.

[0032] The train control host sends a first signal to the power control unit when both the first and third signal acquisition units acquire a low level, sends a second signal to the power control unit when the second signal acquisition unit acquires a low level, and sends a third signal to the power control unit when the third signal acquisition unit acquires a high level, or when the third signal acquisition unit acquires a low level but the first acquisition unit acquires a high level.

[0033] Upon receiving the first signal, the power control unit adjusts the main circuit bus voltage of the tram to U2; upon receiving the second signal, it adjusts the main circuit bus voltage to U3; and upon receiving the third signal, it adjusts the main circuit bus voltage to U1. This creates redundancy between network control and hard-wired control, improving the reliability of charging control.

[0034] To further improve the reliability of charging control, in some embodiments, there are two control units, which are redundant with each other.

[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. Multiple positioning coils are provided, respectively located on the tracks corresponding to the first position, the second position, and the third position.

[0036] This application has at least the following technical effects or advantages:

[0037] 1. This allows the receiver to remain in a constantly raised state during vehicle operation and charging, eliminating the need for frequent raising and lowering operations, thereby extending its service life, reducing driver intervention, and improving charging efficiency.

[0038] 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.

[0039] 3. The redundancy between network control and hard-wired control improves the reliability of charging control. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the charging process of an intermittent tram according to one embodiment of this application;

[0041] Figure 2 This is a schematic diagram of the circuit structure of the hard-wired control device in one embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the circuit structure of a network control device in one embodiment of this application. Detailed Implementation

[0043] To better understand the above technical solutions, the following will provide a detailed explanation of the technical solutions in conjunction with the accompanying drawings and specific implementation methods.

[0044] Example 1

[0045] A charging method for an intermittent tram, the method comprising:

[0046] When the tram reaches the first position, the main circuit bus voltage of the tram is adjusted to U1;

[0047] When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it is charged.

[0048] When the tram leaves the second position, the main circuit bus voltage of the tram is adjusted back to U1;

[0049] When the tram leaves the third position and is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3.

[0050] Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

[0051] like Figure 1 As shown, tram 1 enters the station from A to E to charge.

[0052] When tram 1 reaches the first position B (the end of charging rail 2 closest to the station entrance), the receiver will be about to contact the charging rail, adjusting the main circuit bus voltage of the tram to the pre-charging voltage U1. Since the pre-charging voltage U1 is higher than the output voltage U2 of the charging cabinet 3, arcing between the receiver and the charging rail 2 can be effectively avoided.

[0053] When tram 1 reaches the second position C (charging position), the main circuit bus voltage of tram 1 is adjusted to the output voltage U2 of charging cabinet 3 and charging is started. The on and off of the charging circuit can be controlled by the output contactor K1 of charging cabinet 3. The diode V1 is used to prevent the energy of the energy storage power supply from flowing back to charging cabinet 3 when the main circuit bus voltage of the vehicle is higher than the voltage of charging cabinet 3.

[0054] When charging is complete and tram 1 leaves the second position C (charging position), the main circuit bus voltage of tram 1 is adjusted to U1 again to avoid arcing between the receiver and the charging rail when the receiver is disconnected from the charging rail.

[0055] When tram 1 leaves the third position D (the end of charging rail 2 away from the direction of entry) and runs outside the charging zone (A and E), the main circuit bus voltage of tram 1 is adjusted to the output voltage U3 of the energy storage unit.

[0056] Example 2

[0057] A charging device for an intermittent tram includes:

[0058] A location acquisition unit is used to acquire the real-time location of the tram; and

[0059] Control unit, used for:

[0060] When the tram reaches the first position, the main circuit bus voltage of the tram is adjusted to U1;

[0061] When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it is charged.

[0062] When the tram leaves the second position, the main circuit bus voltage of the tram is adjusted back to U1;

[0063] When the tram leaves the third position and is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3.

[0064] Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

[0065] The location acquisition unit may include a beacon antenna and positioning coils. The beacon antenna is located at the bottom of the tram, and multiple positioning coils are located on the tracks corresponding to the first, second, and third positions, respectively. The location acquisition unit may also employ other existing methods or devices for acquiring the position of rail vehicles, such as using electronic tags and card readers.

[0066] 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 of the tram's energy storage unit, and the other end is electrically connected to the main circuit bus.

[0067] The control unit can be a hardwired control device, a network control device, or a combination of both. This embodiment provides a control unit with a combination of hardwired and network control that is mutually redundant, as detailed below:

[0068] The hard-wired control device includes a power control unit, a signal host, a limit switch, a brake control unit, a first relay, a second relay, and a third relay; the limit switch is the limit switch of the driver's controller and has normally open contacts.

[0069] One end of the limit switch is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal KM1 of the first relay; one end of the signal host is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal KM2 of the second relay; one end of the brake control unit is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal KM3 of the third relay; the first input terminal 11 of the power control unit is electrically connected to the positive terminal of the bus through the normally open contact KM21 of the second relay, and the second input terminal 12 is electrically connected between the first input terminal 11 and the normally open contact KM21 of the second relay through the normally closed contact KM11 of the first relay and the normally closed contact KM31 of the third relay. 13 is the power supply input terminal of the power control unit.

[0070] The signal control unit sends a low level to the coil terminal of the second relay when the tram leaves the third position and is running outside the charging zone, and sends a high level to the coil terminal of the second relay when the tram arrives at the first position.

[0071] The limit switch opens when the driver's handle returns to the original position and closes when the driver's handle is moved to the traction position.

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

[0073] When a low-level signal is detected, the first input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U3; when a low-level signal is detected, the second input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U1, and when a high-level signal is detected, the main circuit bus voltage of the tram is adjusted to U2.

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

[0075] When the vehicle moves from position A to position B, the signal control unit continuously sends a high-level signal to the coil terminal KM2 of the second relay, causing its normally open contact KM21 to close. The control power supply then inputs the high-level signal to the first input terminal 11 of the power control unit through this contact. At this time, since the vehicle is still not at zero speed, the brake control unit continuously outputs a high-level signal to the coil terminal KM3 of the third relay based on the speed signal collected by the speed sensor, causing its normally closed contact KM31 to open. The second input terminal 12 of the power control unit collects a low-level signal and adjusts the main circuit bus voltage of the tram to U1.

[0076] When the vehicle moves from position B to position C, it comes to a complete stop. The driver's control handle returns to its original position, the normally open contact of its limit switch opens, and the coil terminal KM1 of the first relay is de-energized, causing its normally closed contact KM11 to close. The brake control unit 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, causing its normally closed contact KM31 to close. The control power supply inputs a high-level signal to the second input terminal 12 of the power control unit 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.

[0077] When the vehicle finishes charging and leaves position C, the driver operates the driver's control handle at the occupied end to the traction position. The normally open contact of its limit switch closes, and the coil terminal KM1 of the first relay opens its normally closed contact KM11. The second input terminal 12 of the power control unit collects a low-level signal and adjusts the main circuit bus voltage of the tram to U1.

[0078] When the vehicle leaves position D, the signal host outputs a low-level signal to the coil terminal KM2 of the second relay, causing its normally open contact KM21 to open. At this time, the first input terminal 11 of the power control unit collects the low-level signal and adjusts the main circuit bus voltage of the tram to U3.

[0079] The network control device includes a train control host, which has 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 is connected in parallel with the coil terminal KM1 of the first relay, the second signal acquisition unit is connected in parallel with the coil terminal KM2 of the second relay, and the third signal acquisition unit is connected in parallel with the coil terminal KM3 of the third relay. The output terminal of the train control host is electrically connected to the third input terminal of the power control unit.

[0080] When both the first signal acquisition unit IO1 and the third signal acquisition unit IO3 acquire a low level, the train control host sends a first signal to the power control unit. When the second signal acquisition unit IO2 acquires a low level, the host sends a second signal to the power control unit. When the third signal acquisition unit IO3 acquires a high level, or when the third signal acquisition unit IO3 acquires a low level but the first acquisition unit IO1 acquires a high level, the host sends a third signal to the power control unit.

[0081] When the power control unit receives the first signal, it adjusts the main circuit bus voltage of the tram to U2; when it receives the second signal, it adjusts the main circuit bus voltage of the tram to U3; and when it receives the third signal, it adjusts the main circuit bus voltage of the tram to U1.

[0082] When the vehicle is running outside the charging station section (A or E), the signal host sends a low-level signal to the second signal acquisition unit IO2, and the power control unit adjusts the main circuit bus voltage of the tram to U3.

[0083] When a vehicle enters the charging station section (BD), the signal control unit sends a low-level signal to the second signal acquisition unit IO2. When the driver places the traction handle in the 0 position, the first signal acquisition unit IO1 detects a low level. When the driver operates the occupant-end controller handle to the traction position, the first signal acquisition unit IO1 detects a high level. When the speed sensor transmits a zero-speed signal to the brake control unit, the third signal acquisition unit IO3 detects a low level. When the speed sensor transmits a non-zero-speed signal to the brake control unit, the third signal acquisition unit IO3 detects a high level.

[0084] When a vehicle enters the charging station section (BD):

[0085] 1. If the vehicle is not at zero speed at this time, that is, the third signal acquisition unit IO3 acquires a high level, the train control host sends the third signal to the power control unit, and the power control unit adjusts the main circuit bus voltage of the tram to U1.

[0086] 2. If the vehicle is at zero speed and there is no traction command at this time, that is, the third signal acquisition unit IO3 acquires a low level and the first signal acquisition unit IO1 acquires a low level, then the train control host sends the first signal to the power control unit, and the power control unit adjusts the main circuit bus voltage of the tram to U2.

[0087] 3. If the vehicle is at zero speed at this time, but there is a traction command, that is, the third signal acquisition unit IO3 acquires a low level and the first signal acquisition unit IO1 acquires a high level, then the train control host sends the third signal to the power control unit, and the power control unit adjusts the main circuit bus voltage of the tram to U1.

[0088] Furthermore, in addition to the redundancy between the hardwired and network control devices, two redundant control units can also be set up.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A charging method for an intermittent tram, the method comprising: When the tram reaches the first position, the main circuit bus voltage of the tram is adjusted to U1; When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it is charged. When the tram leaves the second position, the main circuit bus voltage of the tram is adjusted back to U1; When the tram leaves the third position and is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3. Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

2. A charging device for an intermittent tram, characterized in that, include: The location acquisition unit is used to acquire the real-time location of the tram. and Control unit, used for: When the tram reaches the first position, the main circuit bus voltage of the tram is adjusted to U1; When the tram reaches the second position, the main circuit bus voltage of the tram is adjusted to U2 and it is charged. When the tram leaves the second position, the main circuit bus voltage of the tram is adjusted back to U1; When the tram leaves the third position and is running outside the charging zone, the main circuit bus voltage of the tram will be adjusted to U3. Wherein, the first position is the end of the charging rail closer to the station entrance, the second position is the charging position, and the third position is the end of the charging rail away from the station entrance; U1 is the pre-charging 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.

3. The charging device for the intermittent tram according to claim 2, characterized in that: The control unit includes a power control unit, a signal host, a limit switch, a first relay, and a second relay; One end of the limit switch is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal of the first relay; One end of the signal host is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal of the second relay; The first input terminal of the power control unit is electrically connected to the positive terminal of the bus 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. The signal host sends a low level to the coil terminal of the second relay when the tram leaves the third position and is running outside the charging zone, and sends a high level to the coil terminal of the second relay when the tram arrives at the first position. The limit switch is open when the driver's handle returns to the original position and closed when the driver's handle is moved to the traction position. When a low-level signal is detected, the first input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U3; when a low-level signal is detected, the second input terminal of the power control unit adjusts the main circuit bus voltage of the tram to U1, and when a high-level signal is detected, the main circuit bus voltage of the tram to U2.

4. The charging device for the intermittent tram according to claim 3, characterized in that: It also includes a brake control unit and a third relay; one end of the brake control unit is electrically connected to the positive terminal of the bus, and the other end is electrically connected to the negative terminal of the bus through the coil terminal 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 sends a low-level signal to the coil terminal of the third relay when the vehicle speed is zero.

5. The charging device for the intermittent tram according to claim 4, characterized in that: The control unit also includes a train control host, which has a first signal acquisition unit, a second signal acquisition unit, and a third signal acquisition unit. The first signal acquisition unit is connected in parallel with the coil terminal of the first relay, the second signal acquisition unit is connected in parallel with the coil terminal of the second relay, and the third signal acquisition unit is connected in parallel with the coil terminal of the third relay. The output terminal of the train control host is electrically connected to the third input terminal of the power control unit. The train control host sends a first signal to the power control unit when both the first and third signal acquisition units acquire a low level, sends a second signal to the power control unit when the second signal acquisition unit acquires a low level, and sends a third signal to the power control unit when the third signal acquisition unit acquires a high level, or when the third signal acquisition unit acquires a low level but the first acquisition unit acquires a high level. When the power control unit receives the first signal, it adjusts the main circuit bus voltage of the tram to U2; when it receives the second signal, it adjusts the main circuit bus voltage of the tram to U3; and when it receives the third signal, it adjusts the main circuit bus voltage of the tram to U1.

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

7. The charging device for an intermittent tram according to any one of claims 2-5, characterized in that: The location acquisition unit includes 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 tracks corresponding to the first position, the second position, and the third position, respectively.

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