WO2023050517A1

WO2023050517A1 - Energy storage traction system and control method therefor, and rail transit vehicle

Info

Publication number: WO2023050517A1
Application number: PCT/CN2021/127244
Authority: WO
Inventors: 蒋奉兵; 张宾; 李学明; 张义; 刘清; 毛康鑫; 何维; 朱宇龙; 徐江辉; 李敏; 熊煜宇
Original assignee: 株洲中车时代电气股份有限公司
Priority date: 2021-09-30
Filing date: 2021-10-29
Publication date: 2023-04-06
Also published as: CN113829887A

Abstract

The present disclosure relates to an energy storage traction system and a control method therefor, and a rail transit vehicle. The system comprises a power-grid power source, a traction transformer, a four-quadrant rectifier, an intermediate direct-current unit, an auxiliary inverter, a traction inverter, an energy storage device, a bidirectional AC/DC converter, a first control switch, a second control switch, a third control switch and a fourth control switch, wherein the energy storage device, the third control switch and a secondary winding of the traction transformer are connected; the energy storage device, the fourth control switch and an output end of the intermediate direct-current unit are connected; and the energy storage device, the second control switch, the bidirectional AC/DC converter and an output end of the auxiliary inverter are connected.

Description

Energy storage traction system, its control method and rail vehicle

Cross References to Related Applications

This disclosure claims priority to the Chinese patent application CN202111161805.0 entitled "Energy storage traction system and its control method and rail vehicle" filed on September 30, 2021, the entire contents of which are incorporated into this disclosure by reference .

technical field

The disclosure belongs to the technical field of rail transportation, and in particular relates to an energy storage type traction system, a control method thereof, and a rail transportation tool.

Background technique

Rail transit trains (EMUs, passenger/freight electric locomotives) can continue to maintain traction in areas without grids if they can not only meet the requirements of the grid power supply system but also have their own energy storage equipment (such as batteries, supercapacitors, fuel cells, etc.) This can not only improve the efficiency of train transportation, but also improve the availability of trains. At the same time, it also has the advantages of greenness and environmental protection. It is an important development trend in the field of rail transit in the world.

In some cases, if the traction function of the energy storage equipment is added to the rail transit train, it is usually considered to add a DC/DC link in the intermediate DC circuit of the traction conversion equipment to realize energy storage and power supply. In order to reduce the size of the energy storage equipment, the DC/DC link often adopts a circuit without isolation. However, in this way, the energy storage equipment and the intermediate DC unit of the traction conversion equipment are directly connected in the same circuit when the grid power supply system is used. The intermediate voltage level of the traction conversion equipment must depend on the rated insulation voltage of the energy storage equipment. If the intermediate voltage level of the traction conversion equipment needs to be increased, the rated insulation voltage of the energy storage equipment must be increased, thereby increasing the volume and weight of the energy storage equipment. and cost key indicators.

Contents of the invention

The main purpose of the present disclosure is to provide an energy storage type traction system and its control method and a rail vehicle, so as to solve the problem that the energy storage device and the intermediate DC unit of the traction converter device are directly connected in the same circuit when the grid power supply system is used. The intermediate voltage level of the traction conversion equipment must depend on the rated insulation voltage of the energy storage equipment. If the intermediate voltage level of the traction conversion equipment needs to be increased, the rated insulation voltage of the energy storage equipment must be increased, thereby increasing the volume and weight of the energy storage equipment. Issues with key metrics of cost.

In view of the above problems, the present disclosure provides a control method for an energy storage traction system. The energy storage traction system includes a grid power supply, a traction transformer, a four-quadrant rectifier, an intermediate DC unit, an auxiliary inverter, a traction inverter, a storage functional equipment, a bidirectional AC/DC converter, a first control switch, a second control switch, a third control switch and a fourth control switch;

The grid power supply, traction transformer, first control switch, four-quadrant rectifier, and intermediate DC unit are connected in sequence. The output end of the intermediate DC unit is connected to the auxiliary load through the auxiliary inverter, and the output end of the intermediate DC unit is also connected to the auxiliary load through the traction inverter. The traction motor is connected;

The energy storage device, the second control switch, the bidirectional AC/DC converter and the auxiliary load are connected in sequence; the energy storage device is also connected to the secondary winding of the traction transformer through the third control switch; the energy storage device is also connected to the secondary winding of the traction transformer through the fourth control switch. The output terminals of the intermediate DC unit are connected;

The control method of the energy storage traction system includes:

If the power supply mode of the energy storage traction system is grid power supply, and the bidirectional AC/DC converter is not faulty, control the first control switch and the second control switch to close, control the third control switch and the fourth control switch to open so that the AC power of the grid power supply is stepped down by the traction transformer, and then the intermediate DC unit is boosted by the four-quadrant rectifier, and the traction voltage obtained by inverting the traction inverter supplies power to the traction motor, and the auxiliary inverter The load voltage obtained by the inverter supplies power to the auxiliary load;

If the charging request sent by the energy storage device is detected, start the bidirectional AC/DC converter, so that the bidirectional AC/DC converter can rectify the load voltage to obtain the charging voltage, and use the charging voltage to charge the energy storage device;

If the power supply mode of the energy storage traction system is power supply for energy storage equipment, and the bidirectional AC/DC converter is not faulty, control the first control switch to open, and control the second switch, the third control switch and the fourth control switch to close , and start the bidirectional AC/DC converter, so that the DC power of the energy storage device will be uncontrolled rectified by the four-quadrant rectifier after passing through the secondary winding of the traction transformer, supplying power to the intermediate DC unit, and reversed by the traction inverter The obtained traction voltage supplies power to the traction motor, and the bidirectional AC/DC converter inverts the direct current of the energy storage device to obtain the load voltage to supply power to the auxiliary load.

The present disclosure also provides an energy storage type traction system, including a grid power supply, a traction transformer, a four-quadrant rectifier, an intermediate DC unit, an auxiliary inverter, a traction inverter, an energy storage device, a bidirectional AC/DC converter, a first control switch, a second control switch, a third control switch and a fourth control switch;

If the power supply mode of the energy storage traction system is grid power supply, and the bidirectional AC/DC converter is not faulty, the first control switch and the second control switch are closed, the third control switch and the fourth control switch are opened, and After the AC power of the power grid is stepped down by the traction transformer, the intermediate DC unit is boosted by the four-quadrant rectifier, and the traction voltage obtained by inversion by the traction inverter supplies power to the traction motor, and the auxiliary inverter performs inversion The resulting load voltage supplies power to the auxiliary load;

If the charging request is sent by the energy storage device, start the bidirectional AC/DC converter, so that the bidirectional AC/DC converter can rectify the load voltage to obtain the charging voltage, and use the charging voltage to charge the energy storage device;

If the power supply mode of the energy storage traction system is power supply for energy storage equipment, and the bidirectional AC/DC converter does not fail, the first control switch is turned off, the second switch, the third control switch and the fourth control switch are closed, And start the bidirectional AC/DC converter, so that the direct current of the energy storage device will be rectified by the four-quadrant rectifier after passing through the secondary winding of the traction transformer, and the intermediate DC unit will be powered, and the traction inverter will be used for inversion The obtained traction voltage supplies power to the traction motor, and the bidirectional AC/DC converter inverts the direct current of the energy storage device to obtain the load voltage to supply power to the auxiliary load.

The present disclosure also provides a rail vehicle, including the above-mentioned energy storage type traction system.

In an exemplary embodiment, the above-mentioned rail vehicle includes at least one of a motor vehicle, a locomotive and an engineering vehicle.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and are used together with the embodiments of the present disclosure to explain the present disclosure, and do not constitute a limitation to the present disclosure.

FIG. 1 is a topological diagram of a grid-powered traction system in the related art;

Fig. 2 is a topological diagram of an energy storage traction system in the related art;

Fig. 3 is a topological diagram of an embodiment of the energy storage traction system of the present disclosure;

Fig. 4 is a working flow chart of the energy storage traction system when the grid power supply is powered under normal working conditions;

Fig. 5 is a working flow chart of the energy storage type traction system when the energy storage device supplies power under normal working conditions;

FIG. 6 is an equivalent circuit diagram when a bidirectional AC/DC converter fails in the energy storage traction system of the present disclosure;

Fig. 7 is the working flow diagram of the energy storage type traction system when the grid power supplies power under the fault condition;

Fig. 8 is a working flow diagram of the energy storage traction system when the energy storage device supplies power under fault conditions;

Fig. 9 is a topological diagram of another embodiment of the energy storage traction system of the present disclosure;

Fig. 10 is the working flow diagram of the energy storage type traction system when the storage power supply is used for power supply under normal working conditions;

Fig. 11 is a working flow chart of the energy storage traction system when the depot is powered by the power supply under fault conditions.

Detailed ways

The implementation of the present disclosure will be described in detail below in conjunction with the accompanying drawings and embodiments, so as to fully understand and implement the implementation process of how the present disclosure uses technical means to solve technical problems and achieve technical effects. It should be noted that, as long as there is no conflict, each embodiment and each feature in each embodiment in the present disclosure can be combined with each other, and the formed technical solutions are all within the protection scope of the present disclosure.

Figure 1 is a topology diagram of the traction system of the grid power supply system in the related art. As shown in Figure 1, the EMU or electric locomotive is usually powered by the grid power supply system (such as 25kV/50Hz), and the main circuit schematic diagram of the traction system is shown in the figure 1, the traction converter device 12 adopts the main and auxiliary integrated structure. The single-phase 25kV/50Hz alternating current passes through the pantograph and the circuit breaker to the traction transformer 11, and after being stepped down by the traction transformer 11, it supplies power to the traction converter 12 through the secondary winding. The traction converter 12 first charges the intermediate DC unit 122 through the pre-charging component 121, then starts the four-quadrant rectifier (Four-Quadrant Converter, 4QC) to raise the intermediate voltage to a stable value, and then passes the traction inverter (Inverter, INV) The three-phase alternating current with adjustable output voltage and frequency enables the traction motor to obtain the desired torque and speed. After passing through the auxiliary inverter (Auxiliary Inverter, AINV), auxiliary transformer, filter, etc., it outputs 0~3AC440V/60Hz auxiliary power as auxiliary power. power supply to the load.

In order to realize the energy storage range extension function, if the traction function of the energy storage device 15 is added to the current rail transit train, it is usually considered to add a DC/DC link 16 in the intermediate DC circuit of the traction conversion device 12 to realize the energy storage and power supply. Figure 2 shows the related technology. Topology diagram of the energy storage traction system. As shown in FIG. 2 , the energy storage device 15 is connected to the intermediate DC circuit through a DC/DC link 16 .

In order to reduce the volume of the energy storage device 15, the DC/DC link 16 often adopts a circuit without isolation. However, in this way, the energy storage device 15 is directly connected to the intermediate DC unit 122 of the traction conversion device 12 in the grid power supply system. In the same circuit, the intermediate voltage level of the traction conversion device 12 must depend on the rated insulation voltage of the energy storage device 15. If the intermediate voltage level of the traction conversion device 12 needs to be increased, the rated insulation voltage of the energy storage device 15 must be increased, thereby The key indicators of the volume, weight and cost of the energy storage device 15 are added.

Therefore, in order to solve the above technical problems, the present disclosure provides the following technical solutions.

3 is a topological diagram of an embodiment of the energy storage traction system of the present disclosure. As shown in FIG. Inverter AINV, traction inverter INV, energy storage device 15, bidirectional AC/DC converter 17, first control switch QS1, second control switch QS2, third control switch QS3 and fourth control switch QS4.

In an exemplary embodiment, the grid power supply 10, the traction transformer 11, the first control switch QS1, the four-quadrant rectifier 4QC, and the intermediate DC unit 122 are connected in sequence, and the output terminal of the intermediate DC unit 122 is connected to the auxiliary load through the auxiliary inverter AINV The output end of the intermediate DC unit 122 is also connected to the traction motor through the traction inverter INV. The energy storage device 15, the second control switch QS2, the bidirectional AC/DC converter 17 and the auxiliary load are connected in sequence; the energy storage device 15 is also connected to the secondary winding of the traction transformer 11 through the third control switch QS3; the energy storage device 15 It is also connected to the output terminal of the intermediate DC unit 122 through the fourth control switch QS4.

In an exemplary embodiment, based on the topology diagram of the energy storage traction system shown in FIG. 3 , the present disclosure also provides a control method for the energy storage traction system. It includes the following steps a to c.

Step a. If the power supply mode of the energy storage traction system is the grid power supply 10, and the bidirectional AC/DC converter 17 is not faulty, control the first control switch QS1 and the second control switch QS2 to close, and control the third control switch QS3 and the fourth control switch QS4 are disconnected, so that the AC power of the grid power supply 10 is stepped down by the traction transformer 11, and then the intermediate DC unit 122 is boosted by the four-quadrant rectifier 4QC, and the traction inverter INV performs inversion to obtain the The traction voltage supplies power to the traction motor, and the load voltage obtained through inversion by the auxiliary inverter AINV supplies power to the auxiliary load.

In an exemplary embodiment, the AC power of the grid power supply 10 is stepped down by the traction transformer 11 to supply power to the traction converter device 12 through the secondary winding, and the four-quadrant rectification module of the traction converter device 12 raises the intermediate voltage to a certain set point. constant voltage. Then, on the one hand, start the traction inverter INV output voltage, three-phase alternating current with adjustable frequency, so that the traction motor can obtain the desired torque and speed to drive the train, or when the train brakes, the traction inverter INV reverses the braking energy Feedback to the intermediate DC unit 122, and then feed back to the grid through the four-quadrant rectification module of the traction conversion device 12; on the other hand, the auxiliary inverter AINV will be started to output auxiliary power to supply power for auxiliary loads.

Step b. If the charging request sent by the energy storage device 15 is detected, start the bidirectional AC/DC converter 17, so that the bidirectional AC/DC converter 17 rectifies the load voltage to obtain a charging voltage, and then uses the charging voltage to charge the storage device. The device 15 can be charged.

In an exemplary embodiment, the energy storage device 15 monitors its own power condition in real time, and sends a charging request when it needs to be charged. The energy storage device 15 is charged after the charging voltage is obtained through rectification.

Step c. If the power supply mode of the energy storage traction system is to supply power to the energy storage device 15, and the bidirectional AC/DC converter 17 does not fail, control the first control switch QS1 to turn off, and control the second switch and the third control switch QS3 and the fourth control switch QS4 are closed, and start the bidirectional AC/DC converter 17, so that after the direct current of the energy storage device 15 passes through the secondary winding of the traction transformer 11, the four-quadrant rectifier 4QC performs uncontrolled rectification, and the intermediate The DC unit 122 supplies power, and the traction voltage obtained by inverting the traction inverter INV supplies power to the traction motor, and the bidirectional AC/DC converter 17 inverts the DC power of the energy storage device 15 to obtain a load voltage for the auxiliary load powered by.

In an exemplary embodiment, the DC power of the energy storage device 15 passes through the 11th side winding of the traction transformer on the one hand, and then passes through the four-quadrant rectifier 4QC for uncontrolled rectification to supply power to the intermediate DC circuit, so that the four-quadrant rectifier 4QC does not operate, and there is no need to The secondary side winding of the traction transformer 11 is chopped, so the heat dissipation is less and the loss is also less, and the use of these devices is safer. Then start the traction inverter INV output voltage, three-phase alternating current with adjustable frequency to make the traction motor obtain the desired torque and speed to drive the train to run or when the train brakes, the traction inverter INV reversely feeds the braking energy to The intermediate DC unit 122 will reversely charge the energy storage device 15 through the four-quadrant rectifier 4QC; on the other hand, it will start the bidirectional AC/DC converter 17, and output three-phase alternating current through "reverse" inverter to supply power for the auxiliary load.

In an exemplary embodiment, the energy storage traction system further includes a pre-charging component 121; the traction transformer 11 and the energy storage device 15 are respectively connected to the four-quadrant rectifier 4QC through the pre-charging component 121 . In this embodiment, before the intermediate DC unit 122 is boosted by the four-quadrant rectifier 4QC, or, before the four-quadrant rectifier 4QC performs uncontrolled rectification and supplies power to the intermediate DC unit 122, it further includes: Cell 122 is precharged.

In an exemplary embodiment, the control method of the energy storage type traction system may also perform the following steps: if the power supply mode of the energy storage type traction system supplies power to the grid power supply 10, the traction inverter INV provides reverse For the braking force, use the four-quadrant rectifier 4QC to invert the braking voltage corresponding to the reverse braking force, and feed it back to the grid power supply 10 .

In an exemplary embodiment, the control method of the energy storage type traction system may further perform the following steps: if the power supply mode of the energy storage type traction system supplies power to the energy storage device 15, the traction inverter INV provides a reverse For the braking force, use the four-quadrant rectifier 4QC to step down the braking voltage corresponding to the reverse braking force, and after obtaining the charging voltage, use the charging voltage to charge the energy storage device 15 .

In the control method of the energy storage type traction system in this embodiment, a bidirectional AC/DC converter 17 that takes power from an auxiliary inverter AINV with a lower voltage level is provided, and the energy storage device 15, the third control switch QS3 , the secondary winding of the traction transformer 11; connect the energy storage device 15, the fourth control switch QS4, and the output end of the intermediate DC unit 122, and connect the energy storage device 15, the second control switch QS2, the bidirectional AC/DC, the auxiliary inverter The output end of the inverter AINV is connected to realize the positive charging of the energy storage device 15 and the reverse power supply for the auxiliary load, and the isolation link can be canceled, which saves the volume and weight of the energy storage extended-range traction system and the main circuit is simple to implement. , has good engineering application value, and at the same time avoids the direct connection of the energy storage device 15 and the intermediate DC unit 122 of the traction converter device 12 in the same circuit. The intermediate voltage level of the traction converter device 12 must depend on the rated voltage of the energy storage device 15 In terms of insulation voltage, the rated insulation voltage of the energy storage device 15 does not need to depend on the voltage level of the intermediate DC unit 122 of the traction converter, which is more conducive to the miniaturization and weight reduction of the energy storage device 15 or the power and voltage level of the traction converter promote.

Fig. 4 is a working flow chart of the energy storage traction system when the power grid is powered under normal working conditions. As shown in FIG. 4 , the working process of the energy storage traction system may include the following steps 400 to 413 .

Step 400 , the grid power supply 10 supplies power.

Step 401, pre-charging link.

Step 402, the four-quadrant rectifier 4QC starts.

Step 403, start the traction inverter INV.

Step 404, output traction force.

Step 405, pulling the train to run.

Step 406, braking the train.

Step 407, exert braking force.

Step 408, start the auxiliary inverter AINV.

Step 409, the auxiliary load starts to work.

Step 410 , whether the energy storage device 15 satisfies the charging condition, if yes, execute step 411 , if not, execute step 413 .

Step 411, the bidirectional AC/DC converter 17 starts.

Step 412, the energy storage device 15 starts charging.

Step 413, the energy storage device 15 is not charged.

It should be noted that the execution order of step 403 and the execution order of step 408 are in no particular order.

Fig. 5 is a working flow chart of the energy storage traction system when the energy storage device supplies power under normal working conditions. As shown in FIG. 5 , the working process of the energy storage traction system may include the following steps 500 to 509 .

Step 500, the energy storage device 15 supplies power.

Step 501, pre-charging link.

Step 502, the four-quadrant rectifier 4QC does not control the rectification.

Step 503, start the traction inverter INV.

Step 504, output traction force.

Step 505, pulling the train to run.

Step 506, braking the train.

Step 507, exert braking force.

Step 508, the bidirectional AC/DC module starts.

Step 509, the auxiliary load starts to work.

It should be noted that the execution order of step 501 and the execution order of step 508 are not in any order.

Fig. 6 is an equivalent circuit diagram when the bidirectional AC/DC converter in the energy storage traction system of the present disclosure fails. In an exemplary embodiment, when the bidirectional AC/DC converter 17 in the energy storage traction system fails, the control method for the energy storage traction system of this embodiment may also perform the following steps a1 to b1.

Step a1, if the power supply mode of the energy storage traction system is the grid power supply 10, and the bidirectional AC/DC converter 17 fails, control the first control switch QS1 to close, control the third control switch QS3 and the fourth control switch QS4 Disconnect, so that after the AC power of the grid power supply 10 is stepped down by the traction transformer 11, the intermediate DC unit 122 is boosted by the four-quadrant rectifier 4QC, and the traction voltage obtained by inverting the traction inverter INV supplies power to the traction motor , the load voltage obtained through inversion by the auxiliary inverter AINV supplies power to the auxiliary load.

Step b1. If the power supply mode of the energy storage traction system is the energy storage device 15, and the bidirectional AC/DC converter 17 fails, control the first control switch QS1 to turn off, control the third control switch QS3 and the fourth control switch The switch QS4 is closed, so that the direct current of the energy storage device 15 passes through the secondary winding of the traction transformer 11, and then is choppered and boosted by the four-quadrant rectifier 4QC to supply power to the intermediate DC unit 122, and is inverted by the traction inverter INV The obtained traction voltage supplies power to the traction motor, and the load voltage obtained through inversion by the auxiliary inverter AINV supplies power to the auxiliary load.

In an exemplary embodiment, the DC power of the energy storage device 15 passes through the 11th side winding of the traction transformer, and then the pre-charging link of the traction converter charges the intermediate DC circuit, and then passes through the four-quadrant rectifier 4QC bidirectional DC/DC "forward" The chopper boost supplies power to the intermediate DC circuit (the chopper reactor is the leakage inductance of the 11th side winding of the traction transformer). Then, on the one hand, start the traction inverter INV output voltage, three-phase alternating current with adjustable frequency, so that the traction motor can obtain the desired torque and speed to drive the train, or when the train brakes, the traction inverter INV reverses the braking energy Feedback to the intermediate DC unit 122 and then through the four-quadrant rectifier 4QC bidirectional DC/DC "reverse" step-down to charge the energy storage device 15; on the other hand, the auxiliary inverter AINV will be started to output auxiliary power to supply power for auxiliary loads.

Fig. 7 is a working flow chart of the energy storage traction system when the grid power supplies power under fault conditions. As shown in FIG. 7 , the working process of the energy storage traction system may include the following steps 700 to 709 .

Step 700 , the grid power supply 10 supplies power.

Step 701, pre-charging link.

Step 702, the four-quadrant rectifier 4QC starts.

Step 703, start the traction inverter INV.

Step 704, output traction force.

Step 705, pulling the train to run.

Step 706, braking the train.

Step 707, exert braking force.

Step 708, start the auxiliary inverter AINV.

Step 709, the auxiliary load starts to work.

It should be noted that the execution order of step 703 and the execution order of step 708 are in no particular order.

Fig. 8 is a working flow chart of the energy storage traction system when the energy storage device supplies power under fault conditions. As shown in FIG. 8 , the working process of the energy storage traction system may include steps 800 to 809 as follows.

Step 800, the energy storage device 15 supplies power.

Step 801, pre-charging link.

Step 802, bidirectional DC/DC chopping by the four-quadrant rectifier 4QC.

Step 803, start the traction inverter INV.

Step 804, output traction force.

Step 805, pulling the train to run.

Step 806, braking the train.

Step 807, exert braking force.

Step 808, start the auxiliary inverter AINV.

Step 809, the auxiliary load starts to work.

It should be noted that the execution order of step 803 is not in any order of execution order of step 808 .

Fig. 9 is a topological diagram of another embodiment of the energy storage traction system of the present disclosure. As shown in FIG. 9 , the energy storage traction system further includes a storage power supply 18 . The storage power supply 18 is connected to the auxiliary load.

In an exemplary embodiment, the control method of the energy storage traction system of this embodiment may also perform the following steps a2 to b2.

Step a2. If the power supply mode of the energy storage traction system is the power supply 18 for the warehouse, and the bidirectional AC/DC converter 17 is not faulty, control the first control switch QS1 and the second control switch QS2 to close, and control the third control switch The switch QS3 and the fourth control switch QS4 are disconnected, and the auxiliary inverter AINV and the traction inverter INV are started, so that the AC power of the storage power supply 18 supplies power to the auxiliary load, and the AC power of the storage power supply 18 is auxiliary inverted After rectified and boosted by the inverter AINV, the intermediate DC unit 122 is powered, and the traction motor is powered by the traction voltage obtained through inversion by the traction inverter INV.

In an exemplary embodiment, the power supply 18 for the warehouse directly supplies power to the auxiliary load; for example, after receiving the instruction of the motor car for the warehouse, the auxiliary inverter AINV is started, and the intermediate voltage is raised to A certain set voltage, and then start the traction inverter INV output voltage, three-phase alternating current with adjustable frequency, so that the traction motor can obtain the desired torque and speed to traction the train.

Step b2, if the charging request sent by the energy storage device 15 is detected, start the bidirectional AC/DC converter 17, so that the bidirectional AC/DC converter 17 can rectify the AC power of the storage power supply 18 to obtain the charging voltage, then use The charging voltage charges the energy storage device 15 .

In an exemplary embodiment, when the energy storage device 15 sends a charging request command, the bidirectional AC/DC module is activated to charge the energy storage unit through "forward" 3 AC/DC rectification.

In an exemplary embodiment, the control method of the energy storage traction system of this embodiment may also perform the following steps a3 to b3.

Step a3. If the power supply mode of the energy storage traction system is the power supply 18 for the warehouse, and the bidirectional AC/DC converter 17 fails, control the first control switch QS1 to turn off, control the third control switch QS3 and the fourth control switch The switch QS4 is closed, and the auxiliary inverter AINV and the traction inverter INV are started, so that the AC power of the storage power supply 18 supplies power to the auxiliary load, and the AC power of the storage power supply 18 is rectified and boosted by the auxiliary inverter AINV , to supply power to the intermediate DC unit 122, and to supply power to the traction motor with the traction voltage obtained through inversion by the traction inverter INV.

In an exemplary embodiment, the storage power supply 18 can still directly supply power to the auxiliary load; at the same time, the auxiliary inverter module is started, and the intermediate voltage is raised to a certain set voltage after being rectified and boosted by three-phase four-terminal PWM. For example, after receiving the depot motor car order, start the traction inverter module output voltage, three-phase alternating current with adjustable frequency, so that the traction motor can obtain the desired torque and speed to drive the train.

Step b3: If the charging request sent by the energy storage device 15 is detected, the DC power of the intermediate DC unit 122 is stepped down by the four-quadrant rectifier 4QC to obtain a charging voltage, and the energy storage device 15 is charged using the charging voltage.

In an exemplary embodiment, after the energy storage unit sends a charge request command, the energy storage unit is charged through the bidirectional DC/DC step-down of the four-quadrant module.

Fig. 10 is a working flow chart of the energy storage type traction system when the storage power supply 18 supplies power under normal working conditions. As shown in FIG. 10 , the working process of the energy storage traction system may include the following steps 100 to 1011 .

Step 100 , the library supplies power with the power supply 18 .

Step 101, the auxiliary load starts to work.

Step 102, whether there is a traction instruction, if there is a traction instruction, execute step 103, if there is no traction instruction, execute step 1011.

Step 103, start the auxiliary inverter AINV.

Step 104, start the traction inverter INV.

Step 105, output traction force.

Step 106, pulling the train to run.

Step 107, whether the energy storage device 15 meets the charging condition, if the energy storage device 15 meets the charging condition, execute step 108, if the energy storage device 15 does not meet the charging condition, execute step 1010.

Step 108, the bidirectional AC/DC converter 17 starts.

Step 109, the energy storage device 15 starts charging.

Step 1010, the energy storage device 15 is not charged.

Step 1011, the auxiliary inverter AINV is not started.

It should be noted that the execution order of step 101, the execution order of step 102, and the execution order of step 108 are not in any order.

Fig. 11 is a working flow chart of the energy storage traction system when the warehouse power supply 18 supplies power under fault conditions. As shown in FIG. 11 , the working process of the energy storage traction system may include the following steps 110 to 1111 .

Step 110 , the library supplies power with the power supply 18 .

Step 111, the auxiliary load starts to work.

Step 112, start the auxiliary inverter module.

Step 113 , whether there is a traction instruction, if there is a traction instruction, execute step 114 , if there is no traction instruction, execute step 117 .

Step 114, start the traction inverter INV.

Step 115, output traction force.

Step 116, pulling the train to run.

Step 117, the auxiliary inverter AINV is not started.

Step 118 , whether the energy storage device 15 meets the charging condition, if the energy storage device 15 meets the charging condition, execute step 119 , if the energy storage device 15 does not meet the charging condition, execute step 1111 .

Step 119, chopping by the four-quadrant rectifier 4QCDC/DC.

Step 1110, the energy storage device 15 starts charging.

Step 1111, the energy storage device 15 is not charged.

The present disclosure also provides a rail vehicle, including the energy storage traction system of the above embodiment. Wherein, the rail vehicle may include at least one of a train, a locomotive and an engineering vehicle.

The energy storage type traction system and its control method and rail vehicle of the present disclosure, by setting a bidirectional AC/DC converter that takes power from an auxiliary inverter with a lower voltage level, the energy storage device, the third control switch , the secondary winding of the traction transformer; connect the output of the energy storage device, the fourth control switch, and the intermediate DC unit, and connect the output of the energy storage device, the second control switch, the bidirectional AC/DC, and the auxiliary inverter , it can charge the energy storage device in the forward direction and supply power to the auxiliary load in the reverse direction, and the isolation link can be canceled, which saves the volume and weight of the energy storage extended-range traction system. The main circuit is simple to implement and has good engineering application value. At the same time, it avoids the problem that the intermediate DC unit of the energy storage equipment and the traction conversion equipment are directly connected in the same circuit. The intermediate voltage level of the traction conversion equipment must depend on the rated insulation voltage of the energy storage equipment, and the rated insulation voltage of the energy storage equipment does not need Relying on the voltage level of the intermediate DC unit of the traction converter is more conducive to the miniaturization and weight reduction of energy storage equipment or the improvement of the power and voltage level of the traction converter.

The present disclosure realizes charging the energy storage device in the forward direction and reversely supplying power to the auxiliary load. At the same time, the energy storage device and the auxiliary inverter are connected in the same circuit, and the rated insulation voltage of the energy storage device does not need to depend on the voltage of the intermediate DC unit. It is more conducive to the miniaturization and weight reduction of energy storage equipment or the improvement of power and voltage levels of traction converters.

Additional features and advantages of the disclosure will be set forth in the description, and in part will be apparent from the description, or can be learned by practice of the disclosure. The objectives and other advantages of the disclosure will be realized and attained by the structure particularly pointed out in the written description, claims hereof as well as the appended drawings.

It can be understood that, the same or similar parts in the above embodiments can be referred to each other, and the content that is not described in detail in some embodiments can be referred to the same or similar content in other embodiments.

It should be noted that, in the description of the present disclosure, terms such as "first" and "second" are used for description purposes only, and should not be understood as indicating or implying relative importance. In addition, in the description of the present disclosure, unless otherwise specified, the meaning of "plurality" means at least two.

In the description of the present disclosure, reference to the terms "one embodiment," "some embodiments," "example," "specific examples," or "some examples" means that specific features described in connection with the embodiment or example , structure, material or characteristic is included in at least one embodiment or example of the present disclosure. In this disclosure, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the described specific features, structures, materials or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

Although the embodiments disclosed in the present disclosure are as above, the described content is only an embodiment adopted for easy understanding of the present disclosure, and is not intended to limit the present disclosure. Anyone skilled in the technical field to which the present disclosure belongs can make any modifications and changes in the form and details of the implementation without departing from the spirit and scope of the present disclosure, but the protection scope of the present disclosure remains The scope defined by the appended claims shall prevail.

Claims

A control method for an energy storage type traction system, the energy storage type traction system includes a grid power supply, a traction transformer, a four-quadrant rectifier, an intermediate DC unit, an auxiliary inverter, a traction inverter, an energy storage device, a bidirectional AC/ DC converter, first control switch, second control switch, third control switch and fourth control switch;

The grid power supply, the traction transformer, the first control switch, the four-quadrant rectifier, and the intermediate DC unit are connected in sequence, and the output end of the intermediate DC unit is connected to the auxiliary load through an auxiliary inverter, so that The output end of the intermediate DC unit is also connected to the traction motor through the traction inverter;

The energy storage device, the second control switch, the bidirectional AC/DC converter and the auxiliary load are sequentially connected; the energy storage device is also connected to the secondary winding of the traction transformer through the third control switch connected; the energy storage device is also connected to the output terminal of the intermediate DC unit through the fourth control switch;

The control method of the energy storage type traction system includes:

If the power supply mode of the energy storage traction system is grid power supply, and the bidirectional AC/DC converter is not faulty, control the first control switch and the second control switch to be closed, and control the second control switch to be closed. The third control switch and the fourth control switch are disconnected, so that after the AC power of the grid power is stepped down by the traction transformer, the intermediate DC unit is boosted by the four-quadrant rectifier, and the traction The traction voltage obtained by inversion by the inverter supplies power to the traction motor, and the load voltage obtained by inversion by the auxiliary inverter supplies power to the auxiliary load;

If the charging request sent by the energy storage device is detected, start the bidirectional AC/DC converter, so that after the bidirectional AC/DC converter rectifies the load voltage to obtain a charging voltage, use the The charging voltage charges the energy storage device;

If the power supply mode of the energy storage traction system is power supply for energy storage equipment, and the bidirectional AC/DC converter is not faulty, control the first control switch to be turned off, control the second switch, the The third control switch and the fourth control switch are closed, and the bidirectional AC/DC converter is started, so that the direct current of the energy storage device passes through the secondary winding of the traction transformer, and then the four-quadrant The rectifier performs uncontrolled rectification to supply power to the intermediate DC unit, and the traction voltage obtained by inverting the traction inverter supplies power to the traction motor, and the bidirectional AC/DC converter supplies power to the traction motor. The DC power of the energy storage device is inverted to obtain a load voltage to supply power to the auxiliary load.
The control method of the energy storage traction system according to claim 1, further comprising:

If the power supply mode of the energy storage traction system is grid power supply, and the bidirectional AC/DC converter fails, the first control switch is controlled to be closed, and the third control switch and the fourth control switch are controlled to be closed. The control switch is turned off, so that after the AC power of the grid power is stepped down by the traction transformer, the four-quadrant rectifier boosts the voltage of the intermediate DC unit, and is obtained by inversion by the traction inverter The traction voltage supplies power to the traction motor, and the load voltage obtained through inversion by the auxiliary inverter supplies power to the auxiliary load;

If the power supply mode of the energy storage traction system is power supply for energy storage equipment, and the bidirectional AC/DC converter fails, the first control switch is controlled to be turned off, and the third control switch and the The fourth control switch is closed, so that the DC power of the energy storage device is choppered and boosted by the four-quadrant rectifier after passing through the secondary winding of the traction transformer to supply power to the intermediate DC unit, and is supplied by the The traction voltage obtained through inversion by the traction inverter supplies power to the traction motor, and the load voltage obtained through inversion by the auxiliary inverter supplies power to the auxiliary load.
The control method of the energy storage traction system according to claim 1, wherein the energy storage traction system further includes a storage power supply; the storage power supply is connected to the auxiliary load;

The control method of the energy storage traction system further includes:

If the power supply mode of the energy storage traction system is power supply for storage, and the bidirectional AC/DC converter is not faulty, control the first control switch and the second control switch to be closed, and control the The third control switch and the fourth control switch are turned off, and the auxiliary inverter and the traction inverter are started, so that the AC power of the storage power supply supplies power to the auxiliary load, and the The AC power of the storage power supply is rectified and boosted by the auxiliary inverter to supply power to the intermediate DC unit, and the traction motor is powered by the traction voltage obtained through inversion by the traction inverter;

If the charging request sent by the energy storage device is detected, the bidirectional AC/DC converter is started, so that the bidirectional AC/DC converter rectifies the AC power of the storage power supply to obtain a charging voltage, The energy storage device is charged with the charging voltage.
The control method of the energy storage traction system according to claim 3, wherein, if the power supply mode of the energy storage traction system is power supply for storage, and the bidirectional AC/DC converter fails, the control unit The first control switch is turned off, the third control switch and the fourth control switch are controlled to be closed, and the auxiliary inverter and the traction inverter are started, so that the AC power of the storage power supply is The auxiliary load supplies power, and after the AC power of the storage power supply is rectified and boosted by the auxiliary inverter, the intermediate DC unit is supplied with power, and the traction inverter performs inversion. The traction voltage supplies power to the traction motor;

If the charging request sent by the energy storage device is detected, the DC power of the intermediate DC unit is stepped down by the four-quadrant rectifier to obtain a charging voltage, and the energy storage device is charged using the charging voltage.
The control method of the energy storage traction system according to claim 1, wherein the energy storage traction system further comprises a pre-charging component;

The traction transformer and the energy storage device are respectively connected to the four-quadrant rectifier through the pre-charging component;

Before boosting the voltage of the intermediate DC unit by the four-quadrant rectifier, or performing uncontrolled rectification by the four-quadrant rectifier, before supplying power to the intermediate DC unit, further comprising:

The intermediate DC unit is pre-charged via the pre-charging component.
The control method of the energy storage traction system according to claim 1, wherein the control method of the energy storage traction system further comprises:

If the power supply mode of the energy storage traction system is grid power supply, the traction inverter provides reverse braking force to the traction motor, and uses the four-quadrant rectifier to brake the corresponding reverse braking force The voltage is inverted and fed back to the grid power supply.
The control method of the energy storage traction system according to claim 1, wherein the control method of the energy storage traction system further comprises:

If the power supply mode of the energy storage type traction system is to supply power to energy storage equipment, the traction inverter provides reverse braking force to the traction motor, and uses the four-quadrant rectifier to provide braking force corresponding to the reverse braking force. The dynamic voltage is lowered to obtain a charging voltage, and the energy storage device is charged using the charging voltage.
An energy storage type traction system, comprising a grid power supply, a traction transformer, a four-quadrant rectifier, an intermediate DC unit, an auxiliary inverter, a traction inverter, an energy storage device, a bidirectional AC/DC converter, a first control switch, a second control switch, a third control switch and a fourth control switch;

The grid power supply, the traction transformer, the first control switch, the four-quadrant rectifier, and the intermediate DC unit are connected in sequence, and the output end of the intermediate DC unit is connected to the auxiliary load through an auxiliary inverter, so that The output end of the intermediate DC unit is also connected to the traction motor through the traction inverter;

The energy storage device, the second control switch, the bidirectional AC/DC converter and the auxiliary load are sequentially connected; the energy storage device is also connected to the secondary winding of the traction transformer through the third control switch connected; the energy storage device is also connected to the output terminal of the intermediate DC unit through the fourth control switch;

If the power supply mode of the energy storage traction system is grid power supply, and the bidirectional AC/DC converter is not faulty, the first control switch and the second control switch are closed, and the third control The switch and the fourth control switch are disconnected, so that the AC power of the grid power supply is stepped down by the traction transformer, and the intermediate DC unit is boosted by the four-quadrant rectifier, and the traction inverter The traction voltage obtained by inverting the auxiliary inverter supplies power to the traction motor, and the load voltage obtained by inverting the auxiliary inverter supplies power to the auxiliary load;

If the charging request sent by the energy storage device, start the bidirectional AC/DC converter, so that after the bidirectional AC/DC converter rectifies the load voltage to obtain a charging voltage, use the charging voltage charging the energy storage device;

If the power supply mode of the energy storage traction system is power supply for energy storage equipment, and the bidirectional AC/DC converter is not faulty, the first control switch is turned off, the second switch, the third control The switch and the fourth control switch are closed, and the bi-directional AC/DC converter is started, so that the direct current of the energy storage device passes through the secondary winding of the traction transformer, and then the four-quadrant rectifier performs non-stop operation. control rectification, supply power to the intermediate DC unit, and supply power to the traction motor by the traction voltage obtained by inverting the traction inverter, and supply power to the energy storage device by the bidirectional AC/DC converter The DC power is inverted to obtain the load voltage to supply power to the auxiliary load.
A rail vehicle, comprising the energy storage type traction system according to claim 9.
The rail vehicle according to claim 9, wherein it comprises at least one of a motor vehicle, a locomotive and an engineering vehicle.