阅读说明：本技术 列车供电系统的救援电路和列车供电系统 (Rescue circuit of train power supply system and train power supply system ) 是由 范斌 刘永江 李自然 易万成 陈湘 彭自坚 冯秋实 姜星友 刘强强 于 2019-11-15 设计创作，主要内容包括：本发明提供一种列车供电系统的救援电路和列车供电系统,通过第一切换单元的一端接入直流电源,另一端接入列车供电系统,同时第二切换单元的一端接入所述直流电源,另一端接入列车供电系统。第一切换单元使能后用于利用直流电源为列车供电系统中的存储器件充电,在列车供电系统中的存储器件充电完成后,第一切换单元便停止工作。然后,第二切换单元使能,并在使能状态下将直流电源提供给列车供电系统对接的负载。这样,在搭载3AC380V供电电源的列车的供电系统发生故障时就可以进行救援,以维持故障列车负载的正常运行。(The invention provides a rescue circuit of a train power supply system and the train power supply system. And the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled, and the first switching unit stops working after the storage device in the train power supply system is charged. Then, the second switching unit is enabled, and supplies the direct-current power supply to the load to which the train power supply system is docked in the enabled state. Thus, when the power supply system of the train carrying the 3AC380V power supply source breaks down, rescue can be carried out so as to maintain normal operation of the broken train load.)

1. A rescue circuit of a train power supply system is characterized by comprising:

one end of the first switching unit is connected with a direct-current power supply, and the other end of the first switching unit is connected with a train power supply system; the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled;

one end of the second switching unit is connected to the direct-current power supply, and the other end of the second switching unit is connected to the train power supply system; the second switching unit is used for enabling after a storage device in the train power supply system is charged, and providing the direct-current power supply to a load butted with the train power supply system in an enabled state; after the storage device in the train power supply system is charged, the first switching unit stops working.

2. The rescue circuit of a train power supply system according to claim 1, wherein the first switching unit includes:

the first connecting branch comprises a first switch and a resistor which are connected in series; one end of the first connecting branch is connected with the direct-current power supply; the other end of the transformer is connected to a first secondary winding of a transformer in the train power supply system;

a second switch; one end of the second switch is connected with the first connecting branch and a connecting point of the first secondary winding of the transformer, and the other end of the second switch is connected with the second secondary winding of the transformer.

3. The rescue circuit of a train power supply system according to claim 2, characterized in that the second switching unit includes: a third switch; wherein:

one end of the third switch is connected with the direct-current power supply, and the other end of the third switch is connected with the second switch, the first connecting branch and a connecting point of the first secondary winding of the transformer.

4. The rescue circuit of a train power supply system according to claim 1, wherein the first switching unit includes:

the first connecting branch comprises a first switch and a first resistor which are connected in series; one end of the first connecting branch is connected with the direct-current power supply; the other end is connected to the front end or the rear end of a rectifier in the train power supply system;

the first connecting branch comprises a first switch and a first resistor which are connected in series; one end of the second connecting branch is connected with the direct-current power supply; the other end is connected to the front end or the rear end of a rectifier in the train power supply system;

the first connecting branch is connected with a position point of a rectifier in the train power supply system and is synchronous with a position point of the second connecting branch which is connected with the rectifier in the train power supply system.

5. The rescue circuit of a train power supply system according to claim 4, characterized in that the second switching unit includes:

a third connection branch comprising a third switch and a first reactor connected in series; wherein: one end of the first connecting branch is connected with the direct-current power supply, and the other end of the first connecting branch is connected with the front end or the rear end of a rectifier in the train power supply system;

a fourth connection branch comprising a fourth switch and a second reactor connected in series; wherein: one end of the fourth connecting branch is connected to the direct-current power supply, and the other end of the fourth connecting branch is connected to the front end or the rear end of a rectifier in the train power supply system;

the third connecting branch is connected with a position point of a rectifier in the train power supply system and is synchronous with a position point of a rectifier in the train power supply system connected with the fourth connecting branch.

6. The rescue circuit of a train power supply system according to any one of claims 1 to 5, characterized by further comprising:

and one end of the voltage sensor is connected to the direct current power supply and is used for detecting whether the direct current power supply is a standard power supply or not.

7. The rescue circuit of a train power supply system according to any one of claims 1 to 5, characterized by further comprising:

and the second voltage sensor is connected with a storage device in the train power supply system in parallel and is used for detecting whether the storage device is charged completely.

8. A train power supply system, comprising:

a rescue circuit of the train power supply system of any one of claims 1 to 7; and a basic power supply unit of the train power supply system.

9. The train power supply system of claim 8, wherein the base power supply unit comprises: a transformer; and the first power supply branch circuit is connected with the first secondary winding of the transformer, and the second power supply branch circuit is connected with the second secondary winding of the transformer.

10. The train power supply system according to claim 8 or 9, wherein each of the first power supply branch and the second power supply branch includes:

and the contactor, the PWM rectifier, the capacitor and the inverter are sequentially connected between the secondary winding of the transformer and the load.

Technical Field

The invention relates to the technical field of circuits, in particular to a rescue circuit of a train power supply system and the train power supply system.

Background

With the development of society, the appearance of trains brings great convenience to people's trip, and at present, the types of trains are more and more, and the trains become important transportation means in people's lives. At present, a domestic main passenger train power supply system adopts a phase-control rectification DC600V power supply, the main passenger train is HXD1D, HXD3C and HXD3D, the loading quantity is large, and the distribution range is wide. Because the train power supply system adopts a DC600V power supply, each passenger train needs to be provided with an inverter to supply power for a three-phase load, and compared with a system scheme that a locomotive rectifies and inverts three-phase alternating current to directly supply power for the passenger train load, the system scheme of centralized direct current supply and decentralized inversion is poor in economy, so that 3AC380V power supply is popularized and carried on the train. When the 3AC380V power supply is popularized to be carried on a train, a scheme for rescuing when the locomotive adopting the 3AC380V power supply fails must be considered.

Sometimes, the train cannot get power from the power grid due to the failure of the pantograph or the train cannot normally pull and run due to the failure of the driver controller, and the train can only be sent back to the destination in a rescue mode of other vehicles. In the process of rescue returning, if the rescue train can normally supply power to the fault train, the auxiliary loads (such as air conditioners, lighting devices, ventilation devices and the like) of the fault train can be maintained to normally run, the comfortable environment for passengers of the fault train can be maintained to the maximum extent, and the working pressure of crew and drivers is relieved. At present, the number of trains carrying the DC600V power supply source is the largest and the distribution is the widest in China, so the power supply system of the train carrying the 3AC380V power supply source is most convenient to carry out fault rescue by using the DC600V power supply source.

Disclosure of Invention

In view of this, the embodiment of the present invention provides a rescue circuit of a train power supply system and a train power supply system, which implement rescue when a power supply system of a train carrying a 3AC380V power supply fails, so as to maintain normal operation of a failed train load.

In order to achieve the above purpose, the embodiments of the present invention provide the following technical solutions:

the invention discloses a rescue circuit of a train power supply system in a first aspect, which comprises:

one end of the first switching unit is connected with a direct-current power supply, and the other end of the first switching unit is connected with a train power supply system; the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled;

one end of the second switching unit is connected to the direct-current power supply, and the other end of the second switching unit is connected to the train power supply system; the second switching unit is used for enabling after a storage device in the train power supply system is charged, and providing the direct-current power supply to a load butted with the train power supply system in an enabled state; after the storage device in the train power supply system is charged, the first switching unit stops working.

Optionally, in the circuit, the first switching unit includes:

the first connecting branch comprises a first switch and a resistor which are connected in series; one end of the first connecting branch is connected with the direct-current power supply; the other end of the transformer is connected to a first secondary winding of a transformer in the train power supply system;

a second switch; one end of the second switch is connected with the first connecting branch and a connecting point of the first secondary winding of the transformer, and the other end of the second switch is connected with the second secondary winding of the transformer.

Optionally, in the circuit described above, the second switching unit includes: a third switch; wherein:

one end of the third switch is connected with the direct-current power supply, and the other end of the third switch is connected with the second switch, the first connecting branch and a connecting point of the first secondary winding of the transformer.

Optionally, in the circuit, the first switching unit includes:

the first connecting branch comprises a first switch and a first resistor which are connected in series; one end of the first connecting branch is connected with the direct-current power supply; the other end is connected to the front end or the rear end of a rectifier in the train power supply system;

the first connecting branch comprises a first switch and a first resistor which are connected in series; one end of the second connecting branch is connected with the direct-current power supply; the other end is connected to the front end or the rear end of a rectifier in the train power supply system;

the first connecting branch is connected with a position point of a rectifier in the train power supply system and is synchronous with a position point of the second connecting branch which is connected with the rectifier in the train power supply system.

Optionally, in the circuit described above, the second switching unit includes:

a third connection branch comprising a third switch and a first reactor connected in series; wherein: one end of the first connecting branch is connected with the direct-current power supply, and the other end of the first connecting branch is connected with the front end or the rear end of a rectifier in the train power supply system;

a fourth connection branch comprising a fourth switch and a second reactor connected in series; wherein: one end of the fourth connecting branch is connected to the direct-current power supply, and the other end of the fourth connecting branch is connected to the front end or the rear end of a rectifier in the train power supply system;

the third connecting branch is connected with a position point of a rectifier in the train power supply system and is synchronous with a position point of a rectifier in the train power supply system connected with the fourth connecting branch.

Optionally, the circuit further includes:

and one end of the voltage sensor is connected to the direct current power supply and is used for detecting whether the direct current power supply is a standard power supply or not.

Optionally, the circuit further includes:

and the second voltage sensor is connected with a storage device in the train power supply system in parallel and is used for detecting whether the storage device is charged completely.

The second aspect of the present invention discloses a train power supply system, including:

a rescue circuit of a train power supply system according to any one of the first aspect of the present invention; and a basic power supply unit of the train power supply system.

Optionally, in the system, the basic power supply unit includes: a transformer; and the first power supply branch circuit is connected with the first secondary winding of the transformer, and the second power supply branch circuit is connected with the second secondary winding of the transformer.

Optionally, in the system described above, the first power supply branch and the second power supply branch both include:

and the contactor, the PWM rectifier, the capacitor and the inverter are sequentially connected between the secondary winding of the transformer and the load.

According to the technical scheme, the rescue circuit of the train power supply system is characterized in that one end of the first switching unit is connected with the direct-current power supply, the other end of the first switching unit is connected with the train power supply system, one end of the second switching unit is connected with the direct-current power supply, and the other end of the second switching unit is connected with the train power supply system. And the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled, and the first switching unit stops working after the storage device in the train power supply system is charged. Then, the second switching unit is enabled, and supplies the direct-current power supply to the load to which the train power supply system is docked in the enabled state. Thus, when the power supply system of the train carrying the 3AC380V power supply source breaks down, rescue can be carried out so as to maintain normal operation of the broken train load.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic diagram of a phase-controlled rectified DC600V power supply according to an embodiment of the present invention;

fig. 2 is a circuit diagram of a rescue circuit of a train power supply system according to another embodiment of the disclosure;

FIG. 3 is a schematic diagram of a PWM rectifier according to another embodiment of the present invention;

fig. 4 is a circuit diagram of a rescue circuit of a train power supply system according to another embodiment of the disclosure.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

As known from the background art, sometimes a train cannot get power from a power grid due to a failure of a pantograph or a driver controller cannot normally pull and run due to a failure, and the train can only be returned to a destination in a rescue mode of other vehicles. In the process of rescue returning, if the rescue train can normally supply power to the fault train, the normal operation of auxiliary loads (such as air conditioners, lighting devices, ventilation devices and the like) of the fault train is maintained, the comfortable environment for passengers of the fault train can be maintained to the maximum extent, and the working pressure of crew and drivers is relieved. At present, the number of trains carrying the DC600V power supply source is the largest and the distribution is the widest in China, so the power supply system of the train carrying the 3AC380V power supply source is most convenient to carry out fault rescue by using the DC600V power supply source.

Based on the above, the embodiment of the invention discloses a rescue circuit of a train power supply system and the train power supply system, which can realize rescue when the power supply system of a train carrying a 3AC380V power supply source fails so as to maintain normal operation of a failed train load.

The embodiment of the invention provides a rescue circuit of a train power supply system, which comprises:

one end of the first switching unit is connected with a direct-current power supply, and the other end of the first switching unit is connected with a train power supply system; and the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled.

When the power supply system of the train on which the 3AC380V power supply source is mounted fails, the power supply system of the train cannot supply power to the load of the train, and therefore, the first switching unit is used to charge the train power supply system. One end of the first switching unit is connected with a direct current power supply, the other end of the first switching unit is connected with a train power supply system, then the first switching unit enters an enabling state, and a storage device in the train power supply system is charged by the direct current power supply in the enabling state.

Alternatively, in another embodiment of the present invention, the DC power source may be a phase-controlled rectified DC600V power source, as shown in fig. 1, the transformer 1 provides a single-phase ac input, the line contactor 2 is used for circuit connection or disconnection, the phase-controlled rectifier bridge 3 converts the ac input into a DC output, the smoothing reactor 4 is used for DC voltage stabilization, the filter capacitor 5 is used for filtering, and the switch 6 is used for connection or disconnection of the DC output of the DC600V power source.

One end of the second switching unit is connected to the direct-current power supply, and the other end of the second switching unit is connected to the train power supply system; the second switching unit is used for enabling after a storage device in the train power supply system is charged, and providing the direct-current power supply to a load butted with the train power supply system in an enabled state; after the storage device in the train power supply system is charged, the first switching unit stops working.

One end of the second switching unit is connected to the dc power supply, and the other end is connected to the train power supply system. After the storage device in the train power supply system is charged, the first switching unit stops working, then the second switching unit is enabled, and the direct-current power supply is provided for the load connected with the train power supply system in the enabled state, so that the normal operation of the fault train load is maintained.

The application provides a train power supply system's rescue circuit, wherein, the one end of first switching unit inserts DC power supply, and the other end inserts train power supply system, and the one end of second switching unit inserts simultaneously DC power supply, the other end inserts train power supply system. And the first switching unit is used for charging a storage device in the train power supply system by using the direct-current power supply after being enabled, and the first switching unit stops working after the storage device in the train power supply system is charged. Then, the second switching unit is enabled, and supplies the direct-current power supply to the load to which the train power supply system is docked in the enabled state. Therefore, when the power supply system of the train breaks down, rescue can be carried out so as to maintain normal operation of the broken train load.

Optionally, in another embodiment of the present invention, another implementation manner of the rescue circuit of the train power supply system is as shown in fig. 2:

a first switching unit comprising:

a first connection branch comprising a switch 22 and a resistor 21 connected in series; one end of the first connecting branch is connected to the positive terminal of the DC600V power supply; the other end is connected with a first secondary winding of a transformer 7 in a train power supply system;

a second switch; one end of the switch 24 is connected to the connection point of the first connection branch and the first secondary winding of the transformer 7, and the other end is connected to the second secondary winding of the transformer 7.

A second switching unit comprising:

a third switch; one end of the switch 21 is connected to the positive terminal of the DC600V power supply, and the other end is connected to the connection point of the switch 24, the first connection branch and the first secondary winding of the transformer 7.

Optionally, in another embodiment of the present invention, referring to fig. 2 as well, the rescue circuit of the train power supply system may further include:

one end of the first voltage sensor, namely the voltage sensor 25, is connected to the DC600V power supply for detecting whether the DC600V power supply is a standard power supply.

A second voltage sensor, voltage sensor 26, is connected in parallel with the support capacitor 12 in the train power supply system, and voltage sensor 27 is connected in parallel with the support capacitor 13 in the train power supply system for detecting whether the storage device is completely charged.

It should be noted that the 3AC380V power supply includes two identical power supply branches, the transformer 7 provides single-phase AC input, the line contactor 8 and the line contactor 9 are used for circuit connection or disconnection, the PWM rectifier 10 and the PWM rectifier 11 convert AC input into dc output, the supporting capacitor 12 and the supporting capacitor 13 are used for dc voltage stabilization and energy storage, the inverter 14 and the inverter 15 invert dc voltage into three-phase AC voltage, and the converter 16 and the converter 17 are used for fixed voltage regulation and convert AC three-phase AC input into three-phase four-wire AC output. The contactors 18, 19 and 20 are used for output power distribution, the first re-power supply branch circuit outputs to close the contactor 18, the second re-power supply branch circuit outputs to close the contactor 20, and the first re-power supply branch circuit and the second re-power supply branch circuit output in parallel to close the contactors 18 and 19.

It should be further noted that, when the train power supply system fails, the primary winding of the transformer 7 is in an open circuit state. The positive terminal of the DC600V power supply is connected to the switch 22, the switch 21 and the voltage sensor 25 at the same time, while the negative terminal of the DC600V power supply is connected to the support capacitor 12 and the support capacitor 13 by two wires, respectively. While the voltage sensor 26 is connected in parallel with the support capacitor 12 and the voltage sensor 27 is connected in parallel with the support capacitor 13.

When the train fault system fault rescue is carried out, the switch 22 and the switch 24 are closed, and other switches are in an off state, so that a positive electrode signal of the DC600V power supply flows to one end of the first heavy power supply branch supporting capacitor 12 through the switch 22, the resistor 23, the first heavy secondary side windings a 1-x 1 of the transformer 7 and the PWM rectifier 10, and charges the supporting capacitor 12. The positive signal of the DC600V power supply flows to one end of the second heavy-duty branch supporting capacitor 13 through the switch 22, the resistor 23, the switch 24, the second heavy-duty winding x2 to a2 of the transformer 7 and the PWM rectifier 10, and charges the supporting capacitor 13. When the sensors 26 and 27 detect that the charging of the support capacitors 12 and 13 is completed, the open switch 22 is closed, the switch 21 is closed, and the inverters 14 and 15 are started. The positive pole signal of the DC600V power supply flows to the inverter 14 through the switch 21, the transformer 7 first secondary winding a1 to x1, and the rectifier 10, and the positive pole signal of the DC600V power supply flows to the inverter 15 through the switch 21, the switch 24, the second secondary winding x2 to a2, and the rectifier 10. The inverter 14 and the inverter 15 convert the direct current signals into alternating current signals and output the alternating current signals to a load butted with a train power supply system.

It should be noted that the resistor 23 can limit the charging current to avoid the impact on the supporting capacitor 12 and the supporting capacitor 13, and the current is usually limited to be within 30A. The secondary winding of the transformer 7 can be used as a line reactor to provide a certain impedance for the circuit, so as to prevent the energy between the filter capacitor 5 of the DC600V power supply, the supporting capacitor 12 of the 3AC380V power supply and the supporting capacitor 13 from being rapidly transferred to generate oscillation. Because the transient voltages of the filter capacitor 5, the support capacitor 12 and the support capacitor 13 cannot be completely consistent, if no reactor provides proper line impedance, the capacitors can be charged and discharged mutually due to voltage difference to form violent oscillation. The current flow directions of the first secondary winding and the second secondary winding of the transformer 7 are opposite, and the voltages generated by the two windings are mutually counteracted to avoid influencing the system.

It should be noted that the principle of the PWM rectifier in the present embodiment is shown in fig. 3. The inverse parallel connection of the diodes of the Insulated Gate Bipolar Transistor (IGBT) elements of the PWM rectifier 10 and the PWM rectifier 11 can prevent the reverse current from flowing, and the current flows in one direction through the diodes, and if the voltage of the support capacitor 12 is higher than the voltage of the support capacitor 13 at a certain time, the current can be prevented from flowing from the support capacitor 12 to the support capacitor 13. When the train power supply system is in fault rescue, the positive signal of the DC600V power supply can flow to the positive line of the intermediate circuit through the diode V3 of the first re-power branch PWM rectifier 10 and flow to the positive line of the intermediate circuit through the diode V1 of the second re-power branch PWM rectifier 11.

In the rescue circuit of the train power supply system provided by this embodiment, the secondary winding of the original transformer 7 of the train power supply system is used as the reactor, so that no extra cost is needed, meanwhile, the current flow directions of the first secondary winding and the second secondary winding of the transformer 7 are opposite, the voltages generated by the two windings are mutually offset to avoid influencing the system, and the anti-reverse current prevention can be realized by using the anti-parallel diodes of the Insulated Gate Bipolar Transistor (IGBT) elements of the PWM rectifier 10 and the PWM rectifier 11, so as to avoid the oscillation caused by mutual energy transfer between capacitors. Therefore, when the power supply system of the train breaks down, effective rescue can be carried out, and meanwhile, the rescue cost is also reduced.

Optionally, in another embodiment of the present invention, another implementation manner of the rescue circuit of the train power supply system is as shown in fig. 4:

a first switching unit comprising:

a first connection branch comprising a switch 22 and a resistor 23 connected in series; one end of the first connecting branch is connected with a DC600V power supply; the other end is connected to the front end of a rectifier 10 in a train power supply system;

a second connection branch comprising a switch 29 and a resistor 30 connected in series; one end of the second connecting branch is connected with a DC600V power supply; the other end is connected to the front end of a rectifier 11 in a train power supply system;

the first connecting branch is connected with a position point of a rectifier 10 in the train power supply system and is synchronous with a position point of the second connecting branch connected with the rectifier 10 in the train power supply system.

A second switching unit comprising:

a third connection branch including a switch 21 and a reactor 30 connected in series; wherein: one end of the first connecting branch is connected with a DC600V power supply, and the other end of the first connecting branch is connected with the front end of a rectifier 10 in a train power supply system;

a fourth connection branch comprising a switch 24 and a reactor 31 in series; wherein: one end of the fourth connecting branch is connected with a DC600V power supply, and the other end of the fourth connecting branch is connected with the front end of a rectifier 11 in a train power supply system;

the third connecting branch is connected with a position point of a rectifier 11 in the train power supply system and is synchronous with a position point of a rectifier 11 in the fourth connecting branch connected with the train power supply system.

It should be noted that, accessing to the front end of the rectifier 10 means that the first connecting branch and the third connecting branch are connected to the rectifier 10, the rectifier 10 is further connected to the supporting capacitor 12, and signals of the first connecting branch and the third connecting branch can only flow to the supporting capacitor 12 through the rectifier 10.

Similarly, the front end of the rectifier 11 is accessed, that is, the second connection branch and the fourth connection branch are connected to the rectifier 11, the rectifier 11 is connected to the support capacitor 13, and signals of the second connection branch and the fourth connection branch can flow to the support capacitor 13 only through the rectifier 11.

Optionally, in another embodiment of the present invention, referring also to fig. 3, the rescue circuit of the train power supply system may further include:

one end of the first voltage sensor, namely the voltage sensor 25, is connected to the DC600V power supply for detecting whether the DC600V power supply is a standard power supply.

A second voltage sensor, voltage sensor 26, is connected in parallel with the support capacitor 12 in the train power supply system, and voltage sensor 27 is connected in parallel with the support capacitor 13 in the train power supply system for detecting whether the storage device is completely charged.

The positive terminal of the DC600V power supply is connected to the switch 22, the switch 21, the switch 24, the switch 29 and the voltage sensor 25, and the negative terminal of the DC600V power supply is connected to the support capacitor 12 and the support capacitor 13 by two wires. While the voltage sensor 26 is connected in parallel with the support capacitor 12 and the voltage sensor 27 is connected in parallel with the support capacitor 13.

It should be noted that, when the train fault system fault rescue is performed, the switch 22 and the switch 28 are closed, and the other switches are both in an open state, and a positive electrode signal of the DC600V power supply flows to one end of the first re-power-supply branch supporting capacitor 12 through the switch 22, the resistor 23 and the PWM rectifier 10, so as to charge the supporting capacitor 12. The positive signal of the DC600V power supply flows to one end of the second re-supply branch supporting capacitor 13 through the switch 28, the resistor 29 and the PWM rectifier 11, and charges the supporting capacitor 13. When the sensors 26 and 27 detect that the charging of the support capacitors 12 and 13 is completed, the switches 22 and 28 are closed and the switches 21 and 24 are opened, and the inverters 14 and 15 are started. The positive-polarity signal of the DC600V power supply flows to the inverter 14 through the switch 21, the reactor 30, and the rectifier 10, and the positive-polarity signal of the DC600V power supply flows to the inverter 15 through the switch 24, the reactor 31, and the rectifier 11. The inverter 14 and the inverter 15 convert the direct current signals into alternating current signals and output the alternating current signals to a load butted with a train power supply system.

It should be noted that the secondary winding of the transformer 7 is no longer used as a reactor of the circuit, but the reactor 30 and the reactor 31 are additionally added, so that a larger impedance can be provided for the circuit to avoid oscillation caused by mutual energy transfer between capacitors.

Optionally, in another embodiment of the present invention, another implementation manner of the rescue circuit of the train power supply system is as follows:

one end of each of the first connecting branch, the second connecting branch, the third connecting branch and the fourth connecting branch is connected with the positive port of the DC600V power supply, the other end of each of the first connecting branch and the third connecting branch is connected to the rear end of a rectifier 10 in the train power supply system, the other end of each of the first connecting branch and the third connecting branch is connected to the rear end of a rectifier 11 in the train power supply system, and the connection mode of the rest components is the same as that of the previous embodiment.

It should be noted that, accessing to the rear end of the rectifier 10 means that the first connection branch and the third connection branch are directly connected to the supporting capacitor 12, and signals of the first connection branch and the third connection branch directly flow to the supporting capacitor 12 without passing through the rectifier 10. Similarly, the connection to the rear end of the rectifier 11 means that the second connection branch and the fourth connection branch are directly connected to the support capacitor 13, and signals of the second connection branch and the fourth connection branch directly flow to the support capacitor 13 without passing through the rectifier 11.

It should be further noted that, due to the connection of the reactor 30 and the reactor 31, the inverse parallel diodes of the Insulated Gate Bipolar Transistor (IGBT) elements of the PWM rectifier 10 and the PWM rectifier 11 may no longer be used for current reversal prevention, and the inductances of the reactor 30 and the reactor 31 may provide a larger impedance to avoid oscillation caused by mutual energy transfer between the capacitors.

Another embodiment of the present invention also provides a train power supply system, including:

the rescue circuit of any one train power supply system in the above example; and a basic power supply unit of the train power supply system.

Optionally, in another embodiment of the present invention, the basic power supply unit includes:

a transformer; and the first power supply branch circuit is connected with the first secondary winding of the transformer, and the second power supply branch circuit is connected with the second secondary winding of the transformer.

Optionally, in another embodiment of the present invention, the first power supply branch and the second power supply branch each include:

and the contactor, the PWM rectifier, the capacitor and the inverter are sequentially connected between the secondary winding of the transformer and the load.

It should be further noted that, in this embodiment, for specific working processes of each component in the basic power supply unit in the train power supply system, reference may be made to corresponding contents in the above several embodiments, and details are not described here again.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.