A main and auxiliary transmission system of an electric locomotive and an electric locomotive

Abstract

The application discloses a kind of electric locomotive main auxiliary transmission system and electric locomotive, including main transformer, the main transformer includes primary winding and at least one traction winding;At least one traction system loop, the traction system loop includes four quadrant rectifier, traction inverter, traction motor and AC isolation contactor;Power battery system loop, the power battery system loop includes power battery and power battery charger;And auxiliary system loop, the auxiliary system loop includes DC / DC converter, power frequency auxiliary inverter, power frequency auxiliary filter and auxiliary system.The electric locomotive main auxiliary transmission system provided by the application ensures the reliable operation of the system under fault condition through the design of bipolar isolation contactor, realizes emergency traction and phase separation area speed reduction control through power battery system, realizes efficient and reliable electric energy conversion by adopting DC-DC-AC conversion mode, and three-phase independent control contactor ensures the safety of motor operation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric locomotive, in particular to an electric locomotive main auxiliary transmission system and electric locomotive. BACKGROUND

[0002] The electric locomotive main auxiliary transmission system is a system that converts the electric energy provided by the external power supply system (such as the catenary or the third rail) to meet the working requirements of the traction motor and auxiliary equipment and adjust their running state through the control system. With the increase of railway transportation demand and the development of technology, people are constantly improving and innovating the electric locomotive main auxiliary transmission system in order to improve its performance in efficiency, energy saving, consumption reduction, reliability and safety, etc.

[0003] In the prior art, as shown in Figure 1 , it is a topology diagram of an AC transmission electric locomotive main auxiliary transmission system. The locomotive traction motor takes power from the traction winding of the main transformer, and the auxiliary system takes power from the auxiliary winding of the main transformer. The traction system and the auxiliary system are electrically isolated and do not affect each other. This main auxiliary transmission system has high redundancy.

[0004] The electric locomotive using this topology scheme has the auxiliary system powered by the auxiliary winding of the main transformer alone, instead of the traction intermediate DC circuit. When the locomotive passes through the neutral section (the neutral section refers to a certain area between the locomotive and the traction transformer, where there is a potential difference, causing the locomotive to be partially or completely unable to obtain power supply.), the auxiliary winding cannot obtain power supply, and the auxiliary system stops working, which may lead to a decrease in locomotive comfort, safety risks, a decrease in operating efficiency, equipment damage and an impact on the traction system.

[0005] In order to solve this problem, the electric locomotive using this topology scheme makes the traction motor work in the regenerative braking state through the control system when the locomotive passes through the neutral section, and supplies power to the auxiliary system through the secondary coupling of the transformer. However, if the control is not good, it will cause overvoltage of the primary side of the main transformer, and voltage impact on the main transformer and the converter system, affecting the normal work of these devices, and even causing damage.

[0006] In the prior art, as shown in Figure 2 , it is another topology diagram of an electric locomotive main auxiliary transmission system. This scheme connects the auxiliary system and the traction system on the same intermediate DC circuit, and the main transformer only provides a traction winding to supply power to the intermediate DC circuit. In this way, the auxiliary system and the traction motor can obtain electric energy from the intermediate DC circuit. The advantage of this scheme is that when the locomotive passes through the neutral section, the energy of the traction motor regenerative braking can be used to supply power to the auxiliary system, ensuring that the auxiliary system is continuously powered. The system control is simple and the risk is small.

[0007] The disadvantage of this scheme is the lack of redundancy, the 3 traction circuits and auxiliary circuits of each bogie share the same intermediate DC circuit, if the intermediate DC circuit is short-circuited or grounded, the entire bogie must be cut off, resulting in half of the power loss of the whole vehicle, affecting the normal use of the locomotive.

[0008] Therefore, the prior art still needs to be improved. SUMMARY

[0009] The main purpose of the present application is to provide a main auxiliary transmission system of an electric locomotive and an electric locomotive, so as to solve the problem that the auxiliary winding of the prior art electric locomotive cannot obtain power when passing through the neutral section, the auxiliary system stops working, which will cause the decline of the comfort of the locomotive, the high safety risk, the reduction of the operation efficiency, the damage of the equipment and the influence on the traction system.

[0010] According to one aspect of the present application, a main auxiliary transmission system of an electric locomotive is provided, comprising:

[0011] A main transformer, the main transformer comprising a primary winding and at least one traction winding, the main transformer being used to convert 25kV high voltage electricity of the catenary into low voltage electricity;

[0012] At least one traction system circuit, the traction system circuit comprising a four-quadrant rectifier for converting alternating current into direct current, a traction inverter for converting intermediate direct current into alternating current for use of a traction motor, the traction motor and an alternating current isolation contactor for cutting off the traction motor;

[0013] A power battery system circuit, the power battery system circuit comprising a power battery and a power battery charger; and

[0014] An auxiliary system circuit, the auxiliary system circuit comprising a DC / DC converter, a power frequency auxiliary inverter, a power frequency auxiliary filter and an auxiliary system.

[0015] Further, the main auxiliary transmission system of the electric locomotive comprises a first traction system circuit, a second traction system circuit and a third traction system circuit, and a bipolar isolation contactor is arranged on the first traction system circuit and the third traction system circuit.

[0016] Further, the traction motor is a permanent magnet motor.

[0017] Further, a discharge circuit is arranged on both sides of the alternating current isolation contactor.

[0018] Further, the power frequency auxiliary inverter adopts auxiliary intermediate direct current voltage closed-loop control.

[0019] Further, a harmonic frequency acquisition system is further arranged in the transmission system, for real-time acquisition of the harmonic frequency of the catenary.

[0020] Further, the auxiliary system circuit adopts a DC-DC-AC converter mode and a high-frequency LLC isolation power supply topology circuit structure.

[0021] Further, at least one SiC element is arranged in the DC / DC converter.

[0022] Further, the AC isolation contactor of the traction motor adopts a three-phase independent control contactor.

[0023] In another aspect, the embodiment of the present application also discloses an electric locomotive comprising the electric locomotive main and auxiliary transmission system according to any one of the above technical solutions.

[0024] By adopting the above technical solutions, the present application has at least the following beneficial effects:

[0025] (1) Ensuring uninterrupted power supply of the auxiliary system when the locomotive passes through the neutral section;

[0026] (2) Enhancing the redundancy of the main and auxiliary transmission system of the locomotive to ensure its reliable operation in the fault mode;

[0027] (3) Solving the problem of power retention when the locomotive passes through the neutral section;

[0028] (4) Improving the efficiency of the auxiliary system and optimizing it in terms of energy saving and noise reduction;

[0029] (5) Improving the efficiency, reliability and safety of the traction system;

[0030] (6) Reducing the harmonic influence of the locomotive on the contactor network;

[0031] (7) Optimizing the control algorithm of the auxiliary system. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0033] Figure 1 A topology diagram of a main and auxiliary transmission system of an AC transmission electric locomotive in the prior art is shown;

[0034] Figure 2 A topology diagram of another main and auxiliary transmission system of an electric locomotive in the prior art is shown.

[0035] Figure 3A topological structure diagram of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0036] Figure 4 A complete topological structure diagram of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0037] Figures 5.1 to 5.3 A current path diagram of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0038] Figures 6.1 to 6.3 A topological structure diagram of an auxiliary system loop of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0039] Figures 7.1 to 7.3 A topological structure diagram of an AC isolation contactor of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0040] Figure 8 A topological structure diagram of a discharge circuit of a main and auxiliary transmission system of an electric locomotive is shown in the figure.

[0041] The reference numerals in the figure are explained as follows:

[0042] 1- first traction system loop; 11- first discharge circuit; 12- first four-quadrant rectifier; 13- second discharge circuit; 14- first traction inverter; 15- first AC isolation contactor; 16- first traction motor; 17- first bipolar isolation contactor;

[0043] 2- second traction system loop; 22- second four-quadrant rectifier; 24- second traction inverter; 25- second AC isolation contactor; 26- second traction motor;

[0044] 3- third traction system loop; 32- third four-quadrant rectifier; 34- third traction inverter; 35- third AC isolation contactor; 36- third traction motor; 37- second bipolar isolation contactor;

[0045] 4- power battery system loop; 40- power battery; 41- power battery charger; 411- filter reactor; 412- diode;

[0046] 5- auxiliary system loop; 50- DC / DC converter; 501- SiC element; 51- power frequency auxiliary inverter; 52- power frequency auxiliary filter; 53- auxiliary system;

[0047] 6- main transformer; 60- primary winding; 61- first traction winding; 62- second traction winding; 63- third traction winding;

[0048] 7- discharge resistor; 8- control coil; 9- main contact. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0050] It should be noted that all uses of "first" and "second" in the embodiments of the present invention are for the purpose of distinguishing two entities or parameters with the same name but different names. It is clear that "first" and "second" are only for the convenience of expression and should not be construed as limiting the embodiments of the present invention. Subsequent embodiments will not explain this in detail.

[0051] like Figure 3 As shown, some embodiments of the present invention disclose a main and auxiliary transmission system for an electric locomotive. Considering that the vehicle has two bogies, each equipped with an identical main and auxiliary transmission system, only one system is described below for ease of explanation. The main and auxiliary transmission system of the electric locomotive includes a main transformer, which includes a primary winding 60 and at least one traction winding. The main transformer is used to convert the 25kV high-voltage electricity from the overhead contact line into low-voltage electricity; at least one traction system circuit, which includes a four-quadrant rectifier that converts AC to DC, a traction inverter that converts intermediate DC to AC for use by the traction motor, a traction motor, and an AC isolation contactor for disconnecting the traction motor; a power battery system circuit, which includes a power battery and a power battery charger; and an auxiliary system circuit, which includes a DC / DC converter, a power frequency auxiliary inverter, a power frequency auxiliary filter, and an auxiliary system 53.

[0052] The electric locomotive main and auxiliary transmission system of the present invention draws power from the traction intermediate DC circuit and uses two bipolar isolation contactors to achieve individual isolation from the two traction intermediate DC circuits; it can be equipped with a power battery system circuit and connected to the traction intermediate DC circuit through a power battery charger to realize speed drop suppression in the lower phase zone, emergency traction, in-depot train operation and permanent magnet motor field weakening control when crossing phases; it can also match power battery chargers with different circuit structures according to the actual application requirements of the locomotive.

[0053] like Figure 4 As shown, the electric locomotive main and auxiliary transmission system of the present invention consists of several parts, including a main transformer 6, a first traction system circuit 1, a second traction system circuit 2, a third traction system circuit 3, a power battery system circuit 4, and an auxiliary system circuit 5.

[0054] In some embodiments, the main transformer 6 is provided with three traction windings, namely a first traction winding 61, a second traction winding 62 and a third traction winding 63, and the first traction winding 61, the second traction winding 62 and the third traction winding 63 are respectively provided with three four-quadrant rectifiers, namely a first four-quadrant rectifier 12, a second four-quadrant rectifier 22 and a third four-quadrant rectifier 32.

[0055] The first traction system circuit 1 is provided with a first traction inverter 14, a first AC isolation contactor 15 and a first traction motor 16.

[0056] The second traction system circuit 2 is provided with a second traction inverter 24, a second AC isolation contactor 25 and a second traction motor 26.

[0057] The third traction system circuit 3 is provided with a third traction inverter 34, a third AC isolation contactor 35 and a third traction motor 36.

[0058] The main transformer 6 mainly converts 25kV high voltage power of the overhead line into low voltage power and provides power for the locomotive through the first traction winding 61, the second traction winding 62 and the third traction winding 63 of the main transformer 6. The four-quadrant rectifiers in the first traction system circuit 1, the second traction system circuit 2 and the third traction system circuit 3 convert AC power of the traction winding of the main transformer 6 into DC power, and the main function of the traction inverter is to convert the intermediate DC power into AC power for the traction motor.

[0059] The AC isolation contactor is mainly used for the removal of the traction motor. The main function of the discharge resistor 7 is to discharge the residual charge of the permanent magnet motor when the traction motor is a permanent magnet motor. The DC / DC converter 50 converts the high voltage DC power of the traction intermediate DC circuit into lower voltage DC power for the auxiliary system 53. The auxiliary inverter converts the DC power of the auxiliary intermediate DC circuit into AC power and filters the AC power through the filter 52 for the auxiliary system 53.

[0060] The main function of the power battery charger 41 is to charge the power battery 40 by reducing the high voltage of the intermediate DC power, and to supply the intermediate DC circuit with the voltage of the power battery 40 by boosting the voltage of the power battery 40 when the power battery 40 needs to be discharged.

[0061] The auxiliary system 53 of the application adopts an intermediate DC circuit to take power, and the DC / DC converter 50 connected to the three intermediate DC circuits realizes the separate isolation of the two traction circuits through the bipolar isolation contactor. This design ensures the redundancy of the locomotive and the uninterrupted power supply requirement of the auxiliary system 53. Even if the four-quadrant rectifier or the traction inverter fails, the whole vehicle only loses the corresponding power.

[0062] The auxiliary system 53 takes power from the traction intermediate DC circuit, and uses two bipolar isolation contactors to achieve individual isolation with the two traction intermediate DC circuits. When the first traction system circuit 1 or the third traction system circuit 3 fails, only the failed traction system circuit needs to be cut off through the first bipolar isolation contactor 17 or the second bipolar isolation contactor 37, and the other traction system circuits and the auxiliary system circuit 5 are not affected and can work normally. When the second traction system circuit 2 fails, the first bipolar isolation contactor 17 or the second bipolar isolation contactor 37 is simultaneously opened, isolating the first traction system circuit 1 or the third traction system circuit 3 from the failed second traction system circuit 2, ensuring that they can still work normally.

[0063] It should be emphasized that the present application uses bipolar isolation contactors, which can simultaneously disconnect the positive and negative of the intermediate DC circuit, ensuring that the failed circuit is completely cut off. The auxiliary system 53 uses the traditional electric locomotive control method to expand power supply through another auxiliary system circuit 5. Any failure of the main auxiliary transmission system components will only cause the corresponding power loss of the whole vehicle. In addition, since the locomotive auxiliary system circuit 5 and the traction system circuit share the intermediate DC link, when the electric locomotive passes through the phase separation area, the energy of the traction motor regenerative braking can be used to power the auxiliary system 53, ensuring that the auxiliary system 53 is continuously powered. The present application ensures the redundancy of the locomotive and the continuous power demand of the auxiliary system 53.

[0064] The electric locomotive can carry a power battery 40 system circuit 4, and connect to the intermediate DC circuit through a power battery charger 41, so that the power battery 40 can output traction power when the locomotive passes through the phase separation area, suppresses the speed drop, eliminates the risk of stopping, improves the transport capacity, and solves the following problems:

[0065] (1) Speed drop in the phase separation area. The power battery 40 system circuit 4 outputs traction power to suppress the speed drop of the locomotive when passing through the phase separation area, eliminating the risk of stopping in the phase separation area;

[0066] (2) Emergency traction. When the locomotive experiences a power failure during operation in a tunnel or bridge section, the power battery 40 system circuit 4 can be used for emergency traction to help the locomotive exit the tunnel or bridge section;

[0067] (3) In-warehouse electric vehicle. No external power source is needed, reducing the workload of connecting external power sources;

[0068] (4) Permanent magnet motor field weakening control during phase separation. When the locomotive traction motor uses a permanent magnet traction motor, in order to prevent the permanent magnet motor backflow from causing device damage to the traction intermediate DC circuit, the power battery 40 system circuit 4 can be used to supply power to the traction inverter to provide field weakening control power after entering the phase separation area, reducing the impact of locomotive speed drop or prolonging the service life of the contactor;

[0069] (5) The auxiliary system 53 is powered when the locomotive is parked, avoiding the influence of the harmonics generated when the locomotive is parked on the catenary;

[0070] (6) The traction power is output by the power battery 40 system loop 4 when the locomotive passes through the neutral section, the speed drop is suppressed, the risk of parking is eliminated, and the transport capacity is improved.

[0071] The main and auxiliary transmission system of the application can match the power battery charger 41 with different circuit structures according to the actual use requirements of the locomotive.

[0072] As shown in Figure 5.1 When the charging power of the power battery 40 is small and the discharging power of the power battery 40 is large, the corresponding power battery charger 41 can be used. When the power battery 40 is charged at a small power, the current path is as shown in Figure 5.2 When the power battery 40 is discharged at a large power, the current path is as shown in Figure 5.3 Using this circuit structure, the charging current is small, so a small-current filter reactor 411 can be selected, reducing the size and weight of the charger. In addition, when the power battery 40 is discharged at a large power, it is directly output through the diode 412, improving the efficiency of the power battery charger 41.

[0073] In some embodiments, the traction motor is a permanent magnet motor, further improving efficiency and energy saving and emission reduction. At the same time, in order to ensure reliable disconnection of the permanent magnet motor in the event of system failure, a three-phase independent control contactor is used.

[0074] On the basis of the above embodiments, in order to prevent the risk of electric shock caused by residual electricity in the permanent magnet motor, a discharge circuit is arranged on both sides of the contact of the AC isolation contactor, enhancing the safety of the locomotive.

[0075] On the basis of the above embodiments, in order to avoid the problem of overvoltage on the output side of the DC / DC converter 50 caused by the variable-frequency auxiliary load during speed regulation, the power-frequency auxiliary inverter 51 uses auxiliary intermediate DC voltage closed-loop control.

[0076] In some embodiments, in order to deal with the catenary resonance problem, a harmonic frequency acquisition system is further provided in the transmission system, which is used to acquire the catenary harmonic frequency in real time and dynamically adjust the switching frequency of the four-quadrant rectifier, effectively reducing the resonance influence of the locomotive on the catenary.

[0077] As shown in Figure 6.1 On the basis of the above embodiments, the auxiliary system loop 5 uses a DC-DC-AC conversion mode and a high-frequency LLC isolation power supply topology circuit structure to achieve efficient and reliable power conversion. The auxiliary system 53 uses a high-frequency isolated DC-DC-AC conversion mode, which has the advantages of miniaturization, low noise and high efficiency.

[0078] This kind of topological circuit structure has the following characteristics:

[0079] 1. The high switching speed and low conduction characteristics of the full SiC element 501 effectively solve the dead zone and temperature rise problems of the IGBT mode in the traditional high-frequency LLC isolated power supply circuit. The input of the DC / DC converter 50 does not require a boost circuit, the topology is simple, and the reliability is high.

[0080] 2. The DC / DC converter 50 can correspond to a wide range of input voltages, and the auxiliary drive system has stronger applicability.

[0081] 3. The circuit uses a half-bridge form, with fewer devices, simple structure, and low cost.

[0082] 4. Multiple intermediate DC voltage application scenarios can be achieved by combination:

[0083] ①As shown in Figure 6.2 , two DC / DC converters 50 are connected in parallel, which can be suitable for medium voltage and high power occasions.

[0084] ②As shown in Figure 6.3 , two DC / DC converters 50 are connected in series, which can be suitable for high voltage and high power occasions.

[0085] On the basis of the above embodiments, at least one SiC element 501 is provided in the DC / DC converter 50, and the SiC element 501 has high switching speed and low conduction characteristics. The use of full SiC element 501 can reduce the volume and weight of the auxiliary converter system, and improve the efficiency.

[0086] On the basis of the above embodiments, in order to ensure normal disconnection of motor current, the AC isolation contactor of the traction motor uses a three-phase independent control contactor. Even if one phase of the contactor is stuck, the motor current can be normally disconnected.

[0087] As shown in Figure 7.1 , the AC isolation contactor of the traction motor uses a three-phase independent control contactor, which has three control coils 8 corresponding to three main contacts 9, ensuring that even if one contactor is stuck, the motor current can be normally disconnected.

[0088] The traditional isolation AC contactor has the following two schemes:

[0089] As shown in Figure 7.2 , one control coil 8 controls the contacts of three phases at the same time. Since the contact action mechanism of the three-phase contactor is three-phase linkage, even if one phase of the contact is stuck or the action mechanism fails, all three phases will be stuck, causing the contact to be unable to be removed.

[0090] As shown inFigure 7.3 As shown, it is another AC isolation contactor scheme, by adopting duplex series contactor, circuit disconnection can be realized when one contactor fails, thereby increasing the redundancy of the system, but the cost and space occupation of the system are increased accordingly.

[0091] When the locomotive adopts a permanent magnet traction motor, the permanent magnet motor will induce an electric potential when it is dragged to rotate without power supply, causing the motor housing or three-phase lead to have a charge, which is easy to cause electric shock injury when the locomotive is returned without fire or the converter system fails, the present application connects six discharge resistors 7 of megohm level in parallel at both ends of the main contact 9 of the AC isolation contactor, for consuming these charges and ensuring the safety of maintenance personnel.

[0092] As shown, Figure 8 When the locomotive adopts a permanent magnet traction motor, when the locomotive enters the split-phase area at high speed, in order to prevent the back electromotive force of the permanent magnet motor from flowing back to the traction intermediate DC circuit and causing device damage, the main and auxiliary drive system topology of the present application can also adopt two sets of intermediate DC circuit discharge circuits. The two sets of intermediate DC circuit discharge circuits are respectively a first discharge circuit 11 and a second discharge circuit 13. The first discharge circuit 11 and the second discharge circuit 13 are respectively for different overvoltage protection values, wherein the protection voltage value of the first discharge circuit 11 is U1, and the protection voltage value of the second discharge circuit 13 is U2, wherein U2>U1, when the back electromotive force of the permanent magnet motor reaches U1, the first discharge circuit 11 consumes the high voltage on the discharge resistor 7 by conducting the power device, when the first discharge circuit 11 fails, the system cannot perform overvoltage suppression when the back electromotive force reaches U1, and the system voltage will continue to rise to U2, at which time the second discharge circuit 13 acts to perform overvoltage suppression protection, the main and auxiliary drive system of the present application ensures the redundancy and reliability of the system by setting two sets of discharge circuits.

[0093] The existing electric locomotive currently adopts a fixed four-quadrant rectifier switching frequency, which is not dynamically adjustable. In order to cope with the catenary resonance problem in the electric system of the locomotive, the present application collects the current and voltage signals of the catenary in real time through a sensor, further analyzes the harmonic frequency, and through continuous monitoring during the operation of the locomotive, the resonance phenomenon can be discovered in time, and by dynamically adjusting the switching frequency of the four-quadrant rectifier, the resonance characteristics of the system can be changed to make it away from the resonance frequency of the catenary, thereby reducing the resonance coupling with the catenary. This helps to reduce the resonance effect of the catenary, and according to the real-time change of the resonance frequency of the catenary, through advanced adaptive, predictive control and artificial neural network control algorithms, real-time adjustment of the switching frequency of the four-quadrant rectifier can be realized, ensuring that the system is always in the optimal working state.

[0094] On the basis of the above embodiments, the application can adopt multiple sensors, each of which collects different frequency bands. Through special design for different frequency bands, each sensor can be optimized and calibrated for its specific frequency band, thereby improving the signal collection accuracy and analysis effect. Through special design for different frequency bands, the resonance phenomenon in a specific frequency range can be more accurately monitored and analyzed, so that different working conditions and requirements can be more flexibly adapted. If one sensor fails or is disturbed, the other sensors can still work, thereby increasing the robustness of the system. Multiple sensors can work simultaneously, allowing parallel processing and analysis, thereby improving the response speed and efficiency of the system.

[0095] In cold weather, the overhead contact line may be iced, affecting the normal operation of the electrical system. The application can dynamically adjust the power factor of the four-quadrant rectifier, use the reactive current generated by the traction converter for deicing, and through intelligent algorithms and control strategies, the system can accurately control the size and direction of the reactive current to achieve the most effective deicing effect and ensure the safe operation of the system.

[0096] The auxiliary motor in the auxiliary system 53 may enter the power generation mode during the speed reduction process, and the feedback power of the auxiliary motor may cause the auxiliary intermediate DC voltage to rise, causing overvoltage. Without appropriate control measures, this may cause damage to the components of the auxiliary converter system. To solve this problem, the power frequency auxiliary inverter 51 in the auxiliary transmission system of the application adopts auxiliary intermediate DC voltage closed-loop control. Through appropriate sensors and monitoring devices, the auxiliary intermediate DC voltage is measured in real time. The real-time measured DC voltage is compared with the predetermined reference value, and then the working state of the auxiliary inverter is adjusted according to the difference. Such closed-loop control ensures that the voltage is maintained within a safe range even under complex working conditions.

[0097] The application also discloses an electric locomotive comprising the electric locomotive main and auxiliary transmission system according to any one of the above technical solutions.

[0098] In summary, the electric locomotive main and auxiliary transmission system and the electric locomotive disclosed in the embodiments of the application have the following beneficial effects:

[0099] (1) Enhance redundancy and reliability: through the special design of the isolation contactor and the protection circuit, it is ensured that any component failure will not affect other parts of the vehicle, improving the redundancy and reliability of the system;

[0100] (2) Optimize energy utilization: by sharing the regenerative braking energy of the traction motor, the auxiliary system 53 is ensured to be continuously powered, reducing energy waste;

[0101] (3) Enhance flexibility and adaptability: can carry power battery 40 system, with the function of phase separation area speed control, emergency traction and indoor motor without external power supply, etc., improve the flexibility of the locomotive and the ability to adapt to different application scenarios;

[0102] (4) Improve safety: by connecting a megohm level discharge resistor 7 and a special discharge circuit in parallel at both ends of the main contactor 9, the safety of the permanent magnet motor operator and maintenance personnel is ensured;

[0103] (5) Improve system efficiency: the high switching speed and low conduction characteristics of SiC elements are used to reduce the volume and weight of the auxiliary converter system and improve efficiency.

[0104] It should be particularly pointed out that each component or step in each of the above embodiments can be crossed, replaced, added, deleted, and therefore, the combinations formed by these reasonable permutations and combinations should also belong to the protection scope of the present application, and the protection scope of the present application should not be limited to the above-mentioned embodiments.

[0105] The above is the exemplary embodiment disclosed by the present application, and the sequence of the above-mentioned embodiments disclosed by the present application is only for description, not representing the advantages and disadvantages of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the embodiments disclosed by the present application (including claims) is limited to these examples, and various changes and modifications can be made without departing from the scope defined by the claims. The functions, steps and / or acts of the method claims described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present application can be described or claimed in singular form, they can also be understood as plural unless explicitly limited to singular.

[0106] Those skilled in the art should understand that the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the embodiments disclosed by the present application (including claims) is limited to these examples; under the idea of the embodiments of the present application, the technical features of the above embodiments or different embodiments can also be combined, and there are many other changes of different aspects of the embodiments of the present application as described above. In order to be brief, they are not provided in detail. Therefore, any omission, modification, equivalent replacement, improvement, etc. made in the spirit and principles of the embodiments of the present application should be included in the protection scope of the embodiments of the present application.

Claims

1. A power locomotive primary and secondary drive system, characterized by, The power locomotive main auxiliary transmission system comprises a main transformer, three traction system loops, a power battery system loop and an auxiliary system loop. The main transformer comprises a primary winding and three traction windings, the three traction windings comprise a first traction winding, a second traction winding and a third traction winding, and each of the traction windings is connected with a four-quadrant rectifier, and the main transformer is used for converting 25kV high voltage power of a catenary into low voltage power. The traction system loop comprises a four-quadrant rectifier for converting alternating current into direct current, a traction inverter for converting intermediate direct current into alternating current for use of a traction motor, the traction motor and an alternating current isolation contactor for cut-off of the traction motor. The power battery system loop comprises a power battery and a power battery charger, and is used for realizing phase area speed reduction suppression, emergency traction, depot motor car and permanent magnet motor field weakening control during passing through a phase. The auxiliary system loop comprises a DC / DC converter, a power frequency auxiliary inverter, a power frequency auxiliary filter and an auxiliary system. The auxiliary system takes power from the traction intermediate direct current loop, and adopts two bipolar isolation contactors to realize single isolation from two traction intermediate direct current loops. When the first traction system loop or the third traction system loop fails, the first bipolar isolation contactor or the second bipolar isolation contactor cuts off the failed traction system loop, and other traction system loops and the auxiliary system loop are not affected and can work normally. When the second traction system loop fails, the first bipolar isolation contactor or the second bipolar isolation contactor is simultaneously opened to isolate the first traction system loop or the third traction system loop from the failed second traction system loop, so that they can still work normally. The main contactor of the alternating current isolation contactor is connected with six discharge resistors in parallel at both ends, and the discharge resistors are used for discharging residual charge of the permanent magnet motor when the traction motor is the permanent magnet motor.

2. The power locomotive primary and secondary drive system of claim 1 wherein, The power locomotive main auxiliary transmission system comprises a first traction system loop, a second traction system loop and a third traction system loop, and the first traction system loop and the third traction system loop are provided with bipolar isolation contactors.

3. The power locomotive primary and secondary drive system of claim 1 wherein, The traction motor is a permanent magnet motor.

4. The power locomotive primary and secondary drive system of claim 1 wherein, The alternating current isolation contactor is provided with a discharge circuit at both sides of the contactor.

5. The power locomotive primary and secondary drive system of claim 1 wherein, The power frequency auxiliary inverter adopts auxiliary intermediate direct current voltage closed loop control.

6. The power locomotive primary and secondary drive system of claim 1 wherein, The transmission system is further provided with a harmonic frequency acquisition system for acquiring a catenary harmonic frequency in real time.

7. The power locomotive primary and secondary drive system of claim 1 wherein, The auxiliary system loop adopts a DC-DC-AC converter mode and a topology circuit structure of high frequency LLC isolation power supply.

8. The power locomotive primary and secondary drive system of claim 1 wherein, The DC / DC converter is provided with at least one SiC element.

9. The power locomotive primary and secondary drive system of claim 1 wherein, The alternating current isolation contactor of the traction motor adopts a 3-phase independent control contactor.

10. An electric locomotive, characterized in that The power locomotive main auxiliary transmission system comprises any one of the above claims 1-9. The power locomotive main auxiliary transmission system comprises any one of the above claims 1-9.

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