Multi-level voltage control method for hybrid locomotive and corresponding hybrid locomotive

Abstract

The present invention discloses a multi-level voltage control method for a hybrid locomotive and a corresponding hybrid locomotive. The method comprises: setting a bus voltage target value of the locomotive, wherein the bus voltage target value includes a first voltage target value V1, a second voltage target value V2, and a third voltage target value V3, wherein V1>V2>V3; the diesel engine of the diesel generator system is always operated at the rated economic speed; and the actual bus voltage V is adjusted by adjusting the main generator excitation of the diesel generator system. 实 Maintain the first voltage target value V1; secondly, adjust the actual charge and discharge power P of the locomotive's power battery system 电实 , the actual bus voltage V 实 Maintain at the second voltage target value V2; finally, adjust the actual power P of the locomotive traction system 牵实 The actual bus voltage V 实 Maintained at the third voltage target value V3. Through multi-level voltage closed-loop control, the performance of each locomotive system is fully utilized, the accuracy and response speed of the locomotive control system are improved, and the energy consumption of the diesel generator system is reduced.

Description

Technical Field

[0001] The present disclosure relates to the technical field of hybrid locomotives, and in particular to a multi-level voltage control method for a hybrid locomotive and a corresponding hybrid locomotive. Background Art

[0002] With the continuous advancement of battery technology, diesel-electric hybrid locomotives are developing in the direction of high-power diesel engines paired with high-power power batteries. As the power of hybrid locomotives increases, how to improve locomotive performance and reduce unnecessary energy loss through the scientific design of hybrid locomotive control systems has become an urgent issue to be solved.

[0003] In diesel-electric hybrid locomotive control, expected power control is typically employed: this involves estimating the expected power of the vehicle load and then adding a control margin to this estimate, which serves as the benchmark for final power control. This control method not only requires dynamic adjustment of the diesel engine speed to match power demand, preventing the engine from consistently operating at an economical fuel consumption point, but also leads to energy waste due to the control margin. Furthermore, since the control benchmark itself is an estimated value and the system is open-loop, it inevitably suffers from low control accuracy, significant susceptibility to the hybrid locomotive's external environment, and an inability to quickly respond to sudden power changes.

[0004] The prior art hybrid locomotive and its energy balance control method and system (CN 111703443 A) comprises the following steps: calculating the power required by all loads based on the power of the load equipment, and adding a certain margin as the expected value of the load power; determining the pre-discharged power of the energy storage element based on the charge and available power of the energy storage element; estimating the power pack power based on the power required by the load and the power of the energy storage element; determining the power pack speed and bus voltage target value based on the power pack power demand; and comparing the actual bus voltage with the target value to determine the charging and discharging of the energy storage element. However, there are the following problems: the diesel engine speed and power need to be adjusted according to the estimated power, and the diesel engine output power cannot be accurately controlled, so the diesel engine cannot always operate at the optimal fuel consumption point; since the control benchmark is the estimated power, the control accuracy will be low and it will be greatly affected by the external environment and the state of the locomotive itself; because the control power is an estimated value, in order to avoid actual power fluctuations causing system overload, a large control margin needs to be reserved, which will result in the locomotive performance not being fully and effectively exerted; the control system based on the estimated power value is an open-loop control system. When the actual power of the locomotive suddenly changes due to idling or other reasons, the control system cannot respond quickly; since the efficiency of equipment such as rectifiers and inverters is estimated, and the power of AC traction motors and AC auxiliary equipment is difficult to accurately calculate, precise control cannot be achieved.

[0005] Based on this, the existing technology still needs to be improved. Summary of the Invention

[0006] In order to solve the above technical problems, the embodiment of the present disclosure provides a multi-level voltage control method for a hybrid locomotive and a corresponding hybrid locomotive. The control method is specifically as follows: setting a bus voltage target value of the hybrid locomotive, the bus voltage target value includes a first voltage target value V1, a second voltage target value V2 and a third voltage target value V3, and V1>V2>V3, V 实 is the actual bus voltage of the power locomotive.

[0007] When the actual power of the locomotive diesel generator system P 油实 Not greater than rated power P 油额 By adjusting the main generator excitation in the diesel generator system, the actual bus voltage V 实 Maintaining the first voltage target value V1;

[0008] When the actual power of the diesel generator system P 油实 Equal to rated power P 油额 , actual bus voltage V 实 Falling, when V 实 = V2, by adjusting the actual charge and discharge power P of the locomotive's power battery system 电实 , the actual bus voltage V 实 Maintaining at the second voltage target value V2, the actual discharge power of the power battery system P 电放 Not greater than the rated discharge power P 额放 ;

[0009] When the actual power of the diesel generator system P 油实 Equal to rated power P 油额 , and the actual discharge power of the power battery system P 电放 Equal to the rated discharge power P 额放 , actual bus voltage V 实 Falling, when V 实 = V3, by adjusting the actual power P of the locomotive's traction system 牵实 The actual bus voltage V 实 Maintained at the third voltage target value V3.

[0010] Among them, the diesel engine of the diesel-generator system always operates at the rated economic speed.

[0011] Furthermore, when V 实 =V1, the power battery system is in charging mode.

[0012] Furthermore, when V 实 =V1, the actual charging power of the power battery system P 电充 Equal to the rated charging power P 额充 .

[0013] Furthermore, when V实 = V2, the power battery system can be in charging or discharging mode, and the actual charging and discharging power P 电实 Dynamic adjustment.

[0014] Furthermore, the power battery system includes a power battery and a DC converter DCDC.

[0015] Furthermore, the power battery system adjusts the charging and discharging power through a DC converter DCDC.

[0016] Furthermore, when V 实 >V3, the actual power of the traction system P 牵实 The traction force output given value P of the locomotive 牵额 Adjustment; when V 实 = V3, the actual power of the traction system P 牵实 According to the actual bus voltage V 实 Adjust the change trend and set the actual bus voltage V 实 Maintained at the third voltage target value V3.

[0017] In addition, an embodiment of the present disclosure further provides a hybrid locomotive, including the above-mentioned multi-level voltage control method for controlling the bus voltage of the power locomotive, wherein the hybrid locomotive includes a diesel generator system, a power battery system, a traction system and an auxiliary system.

[0018] Furthermore, the diesel generator system includes a diesel engine, a generator and a rectifier.

[0019] Furthermore, the traction system includes a traction motor and a traction inverter.

[0020] According to the above technical solution, the present disclosure provides a multi-level voltage control method for a hybrid locomotive and a corresponding hybrid locomotive. The multi-level voltage control method adopts a diesel engine speed maintained at a rated economic speed, and prioritizes the power output strategy of the diesel-generator system to enable the diesel-generator system to operate in an economical power state, thereby reducing the fuel consumption of the power locomotive; through closed-loop control of the multi-level voltage, the performance of each system of the power locomotive can be fully utilized, and the accuracy and response speed of the locomotive control system can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0022] Figure 1 This is a block diagram of a locomotive bus voltage control disclosed in an embodiment of the present invention;

[0023] Figure 2 Schematic diagram of the power of each system under three bus voltage target values ​​disclosed in an embodiment of the present invention;

[0024] Figure 3 This is a topological diagram of the control device disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The detailed description of the following examples and the accompanying drawings are intended to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0026] The present disclosure provides these embodiments in order to make this disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0027] It should be noted that, in the description of this disclosure, unless otherwise specified, "plurality" means greater than or equal to two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are intended solely to facilitate and simplify the description of this disclosure, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0028] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different parts. "Perpendicular" does not mean perpendicular in the strict sense, but rather means within the tolerance range. "Parallel" does not mean parallel in the strict sense, but rather means within the tolerance range. "Include" or "comprising" and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0029] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this disclosure depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0030] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0032] like Figure 1-2 As shown, the present invention discloses a multi-level voltage control method for a power locomotive. The specific control method is as follows: first, the bus voltage target value of the power locomotive is set. The bus voltage target value includes a first voltage target value V1, a second voltage target value V2 and a third voltage target value V3, and V1>V2>V3, V 实 is the actual bus voltage of the power locomotive.

[0033] Specifically, when the target traction power of the locomotive P 牵额 When it is low, the actual power of the diesel generator system P is detected. 油实 Not greater than rated power P 油额 , that is, P 油实 <P 油额 The diesel generator system controls the actual bus voltage V of the power locomotive through excitation control. 实 Maintain at the first voltage target value V1, that is, V 实 = V1.

[0034] When the target traction power of the locomotive is P 牵额 When it increases gradually, the actual power P of the diesel generator system is detected. 油实 Equal to rated power P 油额 After that, P 油实 =P 油额 , control the diesel generator system according to the rated power P 油额 Output. At this time, the diesel generator system can no longer maintain the actual bus voltage V实 At the first target value V1, the actual bus voltage V 实 The bus voltage V 实 After the voltage falls below the first target value V1, the power battery system takes over the actual bus voltage V 实 Control, that is, the diesel generator system is at rated power P 油额 In this state, by adjusting the actual charge and discharge power P of the power battery system of the power locomotive 电实 The actual bus voltage V 实 Maintain at the second voltage target value V2, at this time the actual bus voltage V 实 Controlled by the power battery system at V 实 = V2, actual power of diesel generator system P 油实 Equal to rated power P 油额 , and the actual discharge power of the power battery system P 电放 Not greater than the rated discharge power P 额放 .

[0035] As the locomotive target traction power P 牵额 Continue to increase, if it is detected that the power battery system is in full power discharge state, that is, P 电放 = P 额放 When the power battery system is controlled to discharge at rated power P 额放 Discharge. At this time, the power battery system can no longer maintain the bus voltage V 实 At the second voltage target value V2, the actual bus voltage V 实 It naturally drops below the second voltage target value V2, and the actual bus voltage V 实 After the voltage falls below the second target value V2, the traction system takes over the actual bus voltage V 实 Control, that is, the diesel generator system is at rated power P 油额 And the power battery system at rated discharge power P 额放 In this state, by adjusting the actual power P of the traction system of the power locomotive 牵实 The actual bus voltage V 实 Maintained at the third voltage target value V3, that is, V 实 = V3.

[0036] In one embodiment, when V 实 = V1, the power battery system is in charging mode, that is, the diesel generator system charges the power battery system through the bus. Further, in one embodiment, when V 实 =V1, the actual charging power of the power battery system P 电充 Equal to the rated charging power P 额充 .

[0037] Furthermore, in one embodiment, when V 实 = V2, the power battery system can be in charging or discharging mode, and the actual charging and discharging power P 电实 Dynamic adjustment.

[0038] Furthermore, in one embodiment, Figure 2 As shown, the power battery system includes a power battery and a DC converter DCDC, and the power battery is connected to the busbar through the DC converter DCDC.

[0039] Furthermore, in one embodiment, the power battery system adjusts the charging and discharging power through a DC converter DCDC.

[0040] Furthermore, in one embodiment, the actual power of the traction system P 牵实 Adjust the output value of the traction power of the power locomotive. 实 In the state, PID dynamic closed-loop adjustment is performed on the traction power output given value, and there is no need to obtain accurate real-time traction power dynamic feedback; the auxiliary system power does not participate in the dynamic adjustment of the entire system and does not need to be obtained.

[0041] In addition, an embodiment of the present disclosure further provides a hybrid locomotive, including the above-mentioned multi-level voltage control method for controlling the bus voltage of the hybrid locomotive, wherein the hybrid locomotive includes a diesel generator system, a power battery system, a traction system and an auxiliary system.

[0042] Furthermore, in one embodiment, Figure 2 As shown, the diesel generator system includes a diesel engine, a generator and a rectifier. The rectifier is connected to the busbar, the diesel engine and the generator are mechanically connected, and the generator is connected to the rectifier.

[0043] Furthermore, in one embodiment, Figure 2 As shown, the traction system includes a traction motor and a traction inverter, and the traction motor is connected to the bus through the traction inverter.

[0044] The present invention adopts a control method based on multi-level voltage closed-loop control. The diesel engine speed is maintained at the rated economic speed. A priority control strategy for the power output of the diesel-generator system is adopted to make the diesel-generator system operate in an economical power state, thereby reducing the locomotive's fuel consumption. By controlling the diesel-generator system, the power battery system and the traction system, dynamic closed-loop control of the locomotive bus voltage is achieved, thereby improving control accuracy, fully exerting the locomotive performance, and realizing real-time and rapid response of the locomotive control system. The present invention only needs to collect the easily accessible bus voltage, diesel-generator system output power, and power battery charge and discharge power to perform closed-loop control, while the traction system power and auxiliary system power, which are more difficult to accurately obtain and calculate, do not participate in the quantitative closed-loop control, thereby effectively improving control accuracy. By setting three bus voltage target values, the characteristic that the actual bus voltage will naturally drop when the load is increased when the diesel-generator system or the power battery system is running at full power is utilized to achieve automatic switching of the actual bus voltage between the bus voltage target values.

[0045] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0046] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. In particular, as long as there are no structural conflicts, the various technical features mentioned in the various embodiments may be combined in any manner.

Claims

1. A multi-level voltage control method for a hybrid locomotive, characterized in that: Set the bus voltage target value of the locomotive, which includes a first voltage target value V1, a second voltage target value V2 and a third voltage target value V3, and V1>V2>V3, V 实 is the actual bus voltage of the locomotive, When the actual power of the locomotive diesel generator system P 油实 Not greater than rated power P 油额 By adjusting the main generator excitation in the diesel generator system, the actual bus voltage V 实 Maintaining the first voltage target value V1; When the actual power of the diesel generator system P 油实 Equal to rated power P 油额 , the actual bus voltage V 实 Falling, when V 实 = V2, by adjusting the actual charge and discharge power P of the locomotive's power battery system 电实 , the actual bus voltage V 实 Maintained at the second voltage target value V2, the actual discharge power of the power battery system P 电放 Not greater than the rated discharge power P 额放 ; When the actual power of the diesel generator system P 油实 Equal to rated power P 油额 , and the actual discharge power P of the power battery system 电放 Equal to the rated discharge power P 额放 , the actual bus voltage V 实 Falling, when V 实 = V3, by adjusting the actual power P of the locomotive's traction system 牵实 The actual bus voltage V 实 Maintaining the third voltage target value V3, The diesel engine of the diesel-generator system always operates at a rated economic speed.

2. The multi-level voltage control method for a hybrid locomotive according to claim 1, characterized in that: When V 实 =V1, the power battery system is in charging mode.

3. The multi-level voltage control method for a hybrid locomotive according to claim 2, characterized in that: When V 实 = V1, the actual charging power P of the power battery system 电充 Equal to the rated charging power P 额充 .

4. The multi-level voltage control method for a hybrid locomotive according to claim 3, characterized in that: When V 实 = V2, the power battery system can be in charging or discharging mode, and the actual charging and discharging power P 电实 Dynamic adjustment.

5. The multi-level voltage control method for a hybrid locomotive according to claim 4, characterized in that: The power battery system includes a power battery and a DC converter DCDC.

6. The multi-level voltage control method for a hybrid locomotive according to claim 5, characterized in that: The power battery system adjusts the charging and discharging power through the DC converter DCDC.

7. The multi-level voltage control method for a hybrid electric locomotive according to claim 1, characterized in that: When V 实 >V3, the actual power of the traction system P 牵实 The traction force output given value P of the locomotive 牵额 Adjustment; when V 实 = V3, the actual power of the traction system P 牵实 According to the actual bus voltage V 实 The change trend is adjusted and the actual bus voltage V 实 Maintained at the third voltage target value V3.

8. A hybrid locomotive, characterized in that: The multi-level voltage control method according to any one of claims 1 to 7 is used to control the actual bus voltage of the hybrid locomotive, wherein the hybrid locomotive includes a diesel generator system, a power battery system, a traction system and an auxiliary system.

9. The hybrid locomotive according to claim 8, characterized in that: The diesel generator system includes a diesel engine, a generator and a rectifier.

10. The hybrid locomotive according to claim 8, characterized in that: The traction system includes a traction motor and a traction inverter.

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