An internal electric dual-source locomotive power source hybrid working system and a control method thereof

Abstract

The application discloses an inner electric dual-source locomotive power source mixed working system and a control method thereof. The system comprises a contact net power source module, a diesel engine power source module and a control module. The contact net power source module comprises an electrically connected pantograph and a four-quadrant rectifier, and the diesel engine power source module comprises a diesel engine, an excitation unit and a main generator. The four-quadrant rectifier and the main generator are electrically connected with a locomotive load respectively. The control module is electrically connected with the pantograph, the four-quadrant rectifier, the diesel engine, the main generator and the load respectively. The net voltage of the pantograph and the total load of the locomotive are acquired. According to the net voltage and the total load, the target rotating speed of the diesel engine and the target current of the excitation unit are determined. The diesel engine reaches the target rotating speed, and the excitation unit reaches the target current. According to the total load of the locomotive and the target output power of the main generator, the target output power of the four-quadrant rectifier is determined. By using the above system, the power sources are simultaneously outputted, and the running stability of the locomotive is ensured.

Description

Technical Field

[0001] This invention relates to the technical field of locomotive power sources, and in particular to a hybrid operating system for a locomotive power source with dual internal electric power sources and its control method. Background Technology

[0002] The internally powered dual-source locomotive was developed to meet the needs of applications such as cross-line operation, special train transportation, and railway rescue. Its biggest advantage is that it uses both overhead contact lines and diesel engines as power sources. On electrified railways, it uses the overhead contact lines for power supply, achieving high operating speeds and environmental friendliness. At the same time, it can operate without the constraints of the overhead contact lines, using diesel generator sets for power supply on non-electrified railways, allowing the locomotive to run without stopping or changing locomotives, thus shortening station dwell time. It can also achieve mixed output of both overhead contact lines and diesel engines in abnormal situations such as low overhead contact line voltage.

[0003] Existing methods for controlling the locomotive's power source involve individually controlling either the overhead contact line or the diesel engine, switching between the two power sources as needed, but not simultaneously enabling both the overhead contact line and the diesel engine to output power. However, switching power sources results in a loss of overall traction capacity and driver's cab safety, causing energy fluctuations that negatively impact locomotive operation and the comfort of the driver and passengers. Summary of the Invention

[0004] This invention provides a hybrid power source system and control method for a locomotive with dual internal electric power sources. By simultaneously mixing the output of the overhead contact line and the diesel engine, it avoids energy fluctuations caused by power source switching, ensures uninterrupted traction and power supply, stabilizes the locomotive's operating status, and improves the comfort of the driver and passengers.

[0005] In a first aspect, the present invention provides a hybrid working system for a locomotive power source with dual internal electric power sources, including a catenary power source module, a diesel engine power source module, and a control module;

[0006] The overhead contact line power source module includes an electrically connected pantograph and a four-quadrant rectifier; the diesel engine power source module includes a mechanically connected diesel engine, a main generator, and an excitation unit electrically connected to the main generator; the four-quadrant rectifier and the main generator are electrically connected to the locomotive load, and the control module is electrically connected to the pantograph, the four-quadrant rectifier, the diesel engine, the excitation unit, and the load, respectively.

[0007] The control module is used to obtain the grid voltage of the pantograph and the total load of the locomotive. Based on the grid voltage and the total load of the locomotive, it determines the target speed of the diesel engine and the target current of the excitation unit, and controls the diesel engine to reach the target speed and the excitation unit to reach the target current, so that the main generator can reach the target output power. Based on the total load of the locomotive and the target output power of the main generator, it determines the target output power of the four-quadrant rectifier.

[0008] Optionally, the system also includes a support capacitor; the input terminals of the support capacitor are electrically connected to the four-quadrant rectifier and the main generator, respectively, and the output terminal of the support capacitor is electrically connected to the load.

[0009] The supporting capacitor is used to ensure the stable output of the overhead contact line power from the four-quadrant rectifier and the diesel engine power from the main generator.

[0010] Optionally, the system also includes an inverter unit; the inverter unit is electrically connected between the support capacitor and the load.

[0011] Optionally, the overhead contact line power source module may also include a main circuit breaker and a traction transformer;

[0012] The main circuit breaker and traction transformer are electrically connected in sequence between the pantograph and the four-quadrant rectifier.

[0013] Optionally, the diesel engine power source module also includes a three-phase uncontrolled rectifier;

[0014] The three-phase uncontrolled rectifier is electrically connected between the main generator and the load.

[0015] Optionally, the control module is also used to determine the first speed of the diesel engine based on the grid voltage; determine the second speed of the diesel engine based on the total load of the locomotive; and determine the target speed of the diesel engine based on the first speed and the second speed.

[0016] Secondly, the present invention provides a control method for a hybrid operating system of dual-power locomotives with internal electric sources, applied to the aforementioned hybrid operating system of dual-power locomotives with internal electric sources, the method comprising:

[0017] Obtain the grid voltage of the pantograph and the total load of the locomotive;

[0018] Based on the grid voltage and the total load of the locomotive, the target speed of the diesel engine and the target current of the excitation unit are determined, and the diesel engine is controlled to reach the target speed and the excitation unit to reach the target current so that the main generator can reach the target output power.

[0019] The target output power of the four-quadrant rectifier is determined based on the total load of the locomotive and the target output power of the main generator.

[0020] Optionally, the target speed of the diesel engine can be determined based on the grid voltage and the total load of the locomotive, including:

[0021] Determine the first speed of the diesel engine based on the grid voltage;

[0022] The second speed of the diesel engine is determined based on the total load of the locomotive;

[0023] The maximum value between the first speed and the second speed is determined as the target speed of the diesel engine.

[0024] Optionally, the second speed of the diesel engine is determined based on the total load of the locomotive, including:

[0025] Determine the total power requirement of the locomotive based on its total load;

[0026] Determine the second speed of the diesel engine based on the total power demand.

[0027] Optionally, the target output power of the four-quadrant rectifier is determined based on the locomotive's total load and the main generator's target output power, including:

[0028] Determine the total power requirement of the locomotive based on its total load;

[0029] The difference between the total power demand and the target output power of the main generator is determined as the target output power of the four-quadrant rectifier.

[0030] The technical solution of this invention involves electrically connecting a control module to the pantograph, a four-quadrant rectifier, a diesel engine, an excitation unit, and the load. When the locomotive starts running, the control module acquires the real-time grid voltage of the pantograph and the total load of the locomotive. After acquiring these data, the control module performs a series of logical judgments and calculations to determine the target speed of the diesel engine and the target current of the excitation unit. It then drives the diesel engine to reach the target speed and the excitation unit to reach the target current. When the excitation current of the excitation unit changes, the corresponding output power of the main generator changes. Therefore, when the control module controls the excitation unit to reach the target current, the output power of the main generator also reaches the target output power. After the main generator reaches the target output power, based on the total load of the locomotive and the target output power of the main generator, the target output power of the four-quadrant rectifier is determined through certain logical operations, and the four-quadrant rectifier is controlled to output the corresponding target output power. The above system enables simultaneous mixed output from both overhead contact line and diesel engine power sources, avoiding energy fluctuations caused by power source switching, ensuring uninterrupted traction and power supply, stabilizing locomotive operation, and improving the comfort of drivers and passengers.

[0031] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of a hybrid working system for a locomotive power source with dual internal electric power sources provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the connection relationship of a control module provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of another internal electric dual-source locomotive power source hybrid working system provided in an embodiment of the present invention;

[0036] Figure 4 The present invention provides a flowchart of a control method for a hybrid operating system of dual-power locomotive power sources;

[0037] Figure 5 The present invention provides a flowchart of another control method for a hybrid operating system of dual internal electric locomotive power sources. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] In one embodiment, Figure 1 This is a schematic diagram of the structure of a hybrid working system for a locomotive power source with dual internal electric power sources provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the connection relationship of a control module provided in an embodiment of the present invention. This embodiment is applicable to situations where two power sources, the overhead contact line and the diesel engine, can be used simultaneously to ensure stable locomotive energy and improve the comfort of the driver and passengers. Figure 1 and Figure 2 As shown, the hybrid power system of the locomotive with dual internal power sources includes a catenary power source module 1, a diesel engine power source module 2, and a control module 3. The catenary power source module 1 includes a pantograph 11 and a four-quadrant rectifier 12 that are electrically connected. The diesel engine power source module 2 includes a diesel engine 21, a main generator 22, and an excitation unit 23 that is electrically connected to the main generator 22. The four-quadrant rectifier 12 and the main generator 22 are electrically connected to the locomotive load 4, respectively. The control module 3 is connected to the pantograph 11 and the four-quadrant rectifier, respectively. 12. The diesel engine 21, excitation unit 23, and load 4 are electrically connected; the control module 3 is used to obtain the grid voltage of the pantograph 11 and the total load of the locomotive, determine the target speed of the diesel engine 21 and the target current of the excitation unit 23 based on the grid voltage and the total load of the locomotive, and control the diesel engine 21 to reach the target speed and the excitation unit 23 to reach the target current so that the main generator 22 reaches the target output power; the target output power of the four-quadrant rectifier 12 is determined based on the total load of the locomotive and the target output power of the main generator 22.

[0041] The overhead contact line power source module 1 is a structure that uses the overhead contact line as a power source to provide electrical energy to the locomotive. In this embodiment, the overhead contact line power source module 1 includes a pantograph 11 and a four-quadrant rectifier 12. The pantograph 11 is a mechanical device installed on the roof of the locomotive, typically a folding frame structure with a carbon sliding plate at the top; it makes physical contact with the overhead contact line (high-voltage AC, such as 25kV / 50Hz) through mechanical pantograph raising, thereby introducing electrical energy. Specifically, the pantograph 11 is used to obtain high-voltage AC power from the overhead contact line along the railway line. During locomotive operation, it maintains stable contact with the high-speed moving contact line to ensure a continuous current path. In the event of a short circuit or overvoltage, it can work with a circuit breaker to quickly disconnect from the contact line. The four-quadrant rectifier 12 is an advanced power electronic converter, typically composed of fully controllable devices such as insulated-gate bipolar transistors (IGBTs), capable of bidirectional and controllable conversion between AC and DC. The pantograph 11 is used to convert the single-phase high-voltage AC power (e.g., 25kV / 50Hz) introduced into the locomotive into a stable intermediate DC voltage (e.g., DC 1800V) to supply the locomotive load 4 (e.g., traction inverter, auxiliary system). During this process, even if the contact network voltage fluctuates, a stable intermediate DC voltage can be output. The diesel engine power source module 2 is a structure that uses a diesel engine as a power source to output power to provide electrical energy to the locomotive. In this embodiment, the diesel engine power source module 2 includes a mechanically connected diesel engine 21, an excitation unit 23, and a main generator 22. The diesel engine 21 is an internal combustion engine that generates heat energy by burning diesel fuel, driving the piston to move and converting chemical energy into mechanical energy. The diesel engine 21 generates rotational power by burning diesel fuel, driving the main generator 22 which is directly mechanically connected to it. The excitation unit 23 is a device that changes its own current according to the instructions of the control module 3 to adjust the output power of the main generator 22. The main generator 22 is a large AC generator (usually a three-phase AC synchronous generator or asynchronous generator) rigidly connected coaxially to the diesel engine 21, used to convert the mechanical energy output by the diesel engine into electrical energy. The power of the main generator 22 is matched with the power of the diesel engine 21 to ensure stable power generation under different operating conditions. The control module 3 is the core control module of this embodiment, used to determine the output power of the main generator 22 and the output power of the four-quadrant rectifier 12 based on the grid voltage of the pantograph 11 and the load. The load 4 may include, but is not limited to, traction fans, water pumps, oil pumps, auxiliary units, and power supply equipment.

[0042] Specifically, by electrically connecting the control module 3 to the pantograph 11, the four-quadrant rectifier 12, the diesel engine 21, the excitation unit 23, and the load 4, the control module 3 acquires the real-time grid voltage of the pantograph 11 and the total load of the locomotive when the locomotive starts running. Since the contact network receives electrical energy through the pantograph 11, the real-time grid voltage of the contact network can be directly obtained from the pantograph 11 and thus considered as the real-time grid voltage of the contact network. Furthermore, the real-time grid voltage of the pantograph 11 can be acquired through methods including, but not limited to, setting up a voltage transformer (VT), a high-voltage resistor divider, or a capacitive voltage sensor. The specific method can be determined according to the actual situation and is not limited here. In this embodiment, the total load of the locomotive includes the traction load, the auxiliary unit load, and the train power supply load. For each load, there is a corresponding relationship between load and power; acquiring the load can be understood as acquiring the power. Therefore, the methods for acquiring each power include, but are not limited to, acquiring the current and voltage using current sensors, voltage sensors, etc., and then multiplying the current and voltage to obtain the load power. Of course, besides the methods mentioned above, the total load can also be determined in other ways. For example, the traction load can be calculated by the traction control unit, which can be integrated into control module 3. Auxiliary load can be obtained through measurement by the auxiliary current converter controller. Train power supply load can be obtained through measurement by the train power supply system; there are no restrictions on this method.

[0043] After obtaining the real-time grid voltage of the pantograph 11 and the total load of the locomotive, the control module 3, based on the real-time grid voltage and the total load of the locomotive, performs a series of logical judgments or calculations to determine the target speed of the diesel engine 21 and the target current of the excitation unit 23, and drives the diesel engine 21 to reach the target speed and the excitation unit 23 to reach the target current. When the excitation current of the excitation unit 23 changes, the output power of the corresponding main generator 22 will change. Therefore, when the control module 3 controls the excitation unit 23 to reach the target current, the output power of the corresponding main generator 22 also reaches the target output power. After the main generator 22 reaches the target output power, the control module 3, based on the total load of the locomotive and the target output power of the main generator 22, performs certain logical operations to determine the target output power of the four-quadrant rectifier 12, and controls the four-quadrant rectifier 12 to output the corresponding target output power. At this time, the diesel engine 12 and the contact network simultaneously output power, enabling the load 4 to work normally. In this way, the diesel engine power source module 2 and the contact network power source module 1 work simultaneously, ensuring the smooth operation of the locomotive.

[0044] The technical solution of this invention involves electrically connecting a control module to the pantograph, a four-quadrant rectifier, a diesel engine, an excitation unit, and the load. When the locomotive starts running, the control module acquires the real-time grid voltage of the pantograph and the total load of the locomotive. After acquiring these data, the control module performs a series of logical judgments and calculations to determine the target speed of the diesel engine and the target current of the excitation unit. It then drives the diesel engine to reach the target speed and the excitation unit to reach the target current. When the excitation current of the excitation unit changes, the corresponding output power of the main generator changes. Therefore, when the control module controls the excitation unit to reach the target current, the output power of the main generator also reaches the target output power. After the main generator reaches the target output power, based on the total load of the locomotive and the target output power of the main generator, the target output power of the four-quadrant rectifier is determined through certain logical operations, and the four-quadrant rectifier is controlled to output the corresponding target output power. The above system enables simultaneous mixed output from both overhead contact line and diesel engine power sources, avoiding energy fluctuations caused by power source switching, ensuring uninterrupted traction and power supply, stabilizing locomotive operation, and improving the comfort of drivers and passengers.

[0045] In another specific embodiment, optionally, Figure 3 This is a schematic diagram of another hybrid working system for a locomotive power source with dual internal electric power sources provided in an embodiment of the present invention, with reference to... Figure 2 and Figure 3 As shown, the system also includes a support capacitor 5; the input terminal of the support capacitor 5 is electrically connected to the four-quadrant rectifier 12 and the main generator 22 respectively, and the output terminal of the support capacitor 5 is electrically connected to the load 4; the support capacitor 5 is used to ensure the stable output of the contact network power output by the four-quadrant rectifier 12 and the diesel engine power output by the main generator 22.

[0046] Optional, continue to refer to Figure 2 and Figure 3 The system also includes an inverter unit 6; the inverter unit 6 is electrically connected between the support capacitor 5 and the load 4.

[0047] Optional, continue to refer to Figure 2 and Figure 3 The diesel engine power source module 2 also includes a three-phase uncontrolled rectifier 24; the three-phase uncontrolled rectifier 24 is electrically connected between the main generator 22 and the load 4.

[0048] The supporting capacitor 5, also known as the DC supporting capacitor or intermediate circuit capacitor, is a large-capacity capacitor connected in parallel between the diesel engine power source module 2 and the overhead contact line power source module 1. It is typically a capacitor array composed of multiple capacitor elements. The supporting capacitor 5 primarily receives voltage ripples from the four-quadrant rectifier 12 and the three-phase uncontrolled rectifier 24, providing a stable, low-ripple DC voltage for the subsequent inverter unit 6, ensuring the quality of the inverter output power. When the inverter unit 6 suddenly requires a large current (such as during locomotive starting or acceleration), the supporting capacitor 5 can discharge instantaneously to replenish energy. It also suppresses voltage surges and overvoltages, protecting sensitive components such as the inverter unit 6. The inverter unit 6 is a three-phase inverter bridge composed of fully controlled power devices such as IGBTs or SiC MOSFETs, and is the core control component of the traction drive system. It mainly performs DC-to-AC voltage conversion, that is, it inverts the DC power transmitted from the four-quadrant rectifier 12 and the main generator 22 into three-phase AC power with adjustable frequency, voltage, and phase. The output three-phase AC power is directly supplied to the load 4. The three-phase uncontrolled rectifier 24 is used to convert the three-phase AC power output from the main generator 22 into DC power output to the supporting capacitor 5.

[0049] Specifically, during locomotive operation, for the overhead contact line power source module 1, the four-quadrant rectifier 12 has already converted the AC power from the contact line, therefore the output of the four-quadrant rectifier 12 is DC power, which can be directly transmitted to the supporting capacitor 5. For the diesel engine power source module 2, the main generator 22 outputs AC power, which is transmitted to the three-phase uncontrolled rectifier 24 to convert the AC power into DC power for output to the supporting capacitor 5. The supporting capacitor 5 stabilizes the DC power output from both the overhead contact line and the diesel engine power source to ensure a stable, low-ripple DC voltage for the inverter unit 6, ensuring the power quality of the inverter output. The inverter unit 6 converts the stable DC power into adjustable three-phase AC power, supplying power to the various loads 4 of the locomotive, ensuring stable locomotive operation, improving the comfort and experience of the driver and passengers, and simultaneously achieving efficient utilization of different power sources.

[0050] Optional, continue to refer to Figure 2 and Figure 3 The overhead contact line power source module 1 also includes a main circuit breaker 13 and a traction transformer 14; the main circuit breaker 13 and the traction transformer 14 are electrically connected in sequence between the pantograph 11 and the four-quadrant rectifier 12.

[0051] The main circuit breaker 13 is a high-voltage, high-current automatic switching device, typically a vacuum circuit breaker, installed in the high-voltage compartment or cabinet on the top of the locomotive. When the main circuit breaker 13 is closed, the high-voltage circuit from the pantograph 11 to the traction transformer 14 is connected, and the locomotive begins to draw power from the overhead contact line. The main circuit breaker 13 also serves as a fault protection and electrical isolation device. That is, when a serious fault occurs in the main circuit, the main circuit breaker 13 can quickly cut off the large current within tens of milliseconds, protecting the locomotive equipment. After the main circuit breaker 13 is opened, a clear air insulation gap is formed, ensuring that the high-voltage circuit is completely de-energized during rooftop work or maintenance, guaranteeing personnel safety. The traction transformer 14 is one of the core components of the electric locomotive. It is a multi-winding, high-power oil-immersed or dry-type transformer used to convert the high-voltage electricity from the overhead contact line into low-voltage electricity suitable for the traction system.

[0052] Specifically, the pantograph 11 obtains high-voltage AC power (such as 25kV / 50Hz) from the contact network. After the high-voltage AC power is switched on and off and protected by the main circuit breaker 13, it enters the traction transformer 14 for voltage transformation and electrical isolation, so that the high-voltage power is converted into low-voltage power. The low-voltage power is output to the four-quadrant rectifier 12, which performs AC / DC conversion and outputs it to the support capacitor 5.

[0053] It should be noted that, under normal circumstances, when both the overhead contact line and the diesel engine are connected simultaneously, different issues need to be considered. When the overhead contact line power source is input, the voltage Udc across the supporting capacitor 5 is related to the pantograph voltage (i.e., the overhead contact line voltage) Us, and the two satisfy the relationship: Udc ≥ 1.414 × Us / K, where K is the primary-secondary voltage transformation ratio of the traction transformer 14. When the diesel engine power source is input, the voltage Udc across the supporting capacitor 5 is related to the output voltage Uac of the main generator 22 corresponding to the diesel engine speed, and the two satisfy the relationship Udc = 1.35 × Uac. It can be seen that the issues considered for the two power sources are different. However, the technical solution of this embodiment overcomes the problem of the wide range of considerations mentioned above, and realizes the effect of energy output by mixing the two power sources to jointly drive the load operation.

[0054] Optional, continue to refer to Figure 2 and Figure 3 The control module 3 is also used to determine the first speed of the diesel engine 21 based on the grid voltage; determine the second speed of the diesel engine 21 based on the total load of the locomotive; and determine the target speed of the diesel engine 21 based on the first speed and the second speed.

[0055] Specifically, when determining the target speed of the diesel engine 21, the control module 3 needs to determine the first speed of the diesel engine 21 based on the real-time grid voltage of the pantograph 11. There may be a preset relationship between the pantograph 11 and the first speed of the diesel engine 21. Within a preset fluctuation range of the real-time grid voltage, the first speed of the diesel engine 21 remains unchanged. Therefore, after obtaining the grid voltage, the first speed of the diesel engine 21 corresponding to the real-time grid voltage of the pantograph 11 can be determined. Simultaneously, the control module 3 will also determine the second speed of the diesel engine 21 based on the total load of the locomotive. In this process, the control module 3 can determine the total power demand of the locomotive based on the total load. The specific determination method may include, but is not limited to, determining it through establishing a preset correspondence or logical operations, etc., and is not limited here. After determining the total power demand of the locomotive, the second speed of the diesel engine 21 can be determined based on the total power demand and through preset correspondence or logical operations. After determining the first and second speeds of the diesel engine, the control module 3 can determine the target speed of the diesel engine 21 based on the first and second speeds. The specific determination method can be determined according to the actual situation, such as comparing the magnitudes or determining it through logical operations between the three, and is not limited here. In this embodiment, the control module 3 determines the maximum value of the first and second speeds as the target speed of the diesel engine 21, and controls the diesel engine 21 to reach the target speed.

[0056] Based on the same inventive concept Figure 4 This invention provides a flowchart of a control method for a hybrid power source system for a locomotive with dual internal electric power sources, applicable to the aforementioned hybrid power source system for a locomotive with dual internal electric power sources. (Refer to...) Figure 4 As shown, the method includes:

[0057] S110. Obtain the pantograph voltage and the total load of the locomotive;

[0058] S120. Based on the grid voltage and the total load of the locomotive, determine the target speed of the diesel engine and the target current of the excitation unit, and control the diesel engine to reach the target speed and the excitation unit to reach the target current, so that the main generator can reach the target output power.

[0059] S130. Determine the target output power of the four-quadrant rectifier based on the total load of the locomotive and the target output power of the main generator.

[0060] Specifically, when the locomotive starts running, the real-time grid voltage of the pantograph and the total load of the locomotive are acquired. Since the overhead contact line receives electrical energy through the pantograph, the real-time grid voltage of the contact line can be directly obtained from the pantograph's real-time grid voltage, which can be considered the real-time grid voltage of the contact line. Furthermore, the real-time grid voltage of the pantograph can be acquired through methods including, but not limited to, setting up voltage transformers (VT), high-voltage resistor dividers, or capacitive voltage sensors, depending on the actual situation, and is not limited here. In this embodiment, the total load of the locomotive includes traction load, auxiliary unit load, and train power supply load. For each load, there is a corresponding relationship between load and power; acquiring the load can be understood as acquiring the power. Therefore, the methods for acquiring each power can include, but are not limited to, current sensors, voltage sensors, etc. After acquiring the current and voltage, multiplying the current and voltage gives the load power. Of course, besides the above methods, other methods can also be used to determine the total load; for example, the traction load can be calculated by the integrated traction control unit. The auxiliary load can be obtained by measuring through the auxiliary current converter controller. The train's power supply load can be obtained through measurement by the train's power supply system, and there are no restrictions on this.

[0061] After obtaining the real-time grid voltage of the pantograph and the total load of the locomotive, the target speed of the diesel engine and the target current of the excitation unit can be determined through a series of logical judgments or calculations based on the real-time grid voltage and the total load of the locomotive. The diesel engine is then driven to reach the target speed, and the excitation unit reaches the target current. When the excitation current of the excitation unit changes, the output power of the corresponding main generator changes. Therefore, when the excitation unit reaches the target current, the output power of the corresponding main generator also reaches the target output power. After the main generator reaches the target output power, the target output power of the four-quadrant rectifier can be determined through certain logical operations based on the total load of the locomotive and the target output power of the main generator. The four-quadrant rectifier is then controlled to output the corresponding target output power. At this time, the diesel engine and the overhead contact line simultaneously output power, ensuring normal load operation. This achieves simultaneous operation of the diesel engine power source module and the overhead contact line power source module, ensuring the smooth operation of the locomotive.

[0062] The technical solution of this invention involves obtaining the pantograph's grid voltage and the locomotive's total load; determining the target speed of the diesel engine and the target current of the excitation unit based on the grid voltage and the locomotive's total load, and controlling the diesel engine to reach the target speed and the excitation unit to reach the target current, so that the main generator reaches the target output power; and determining the target output power of the four-quadrant rectifier based on the locomotive's total load and the main generator's target output power. Using this method, simultaneous mixed output from both the overhead contact line and the diesel engine is achieved, avoiding energy fluctuations caused by power source switching, ensuring uninterrupted traction and power supply, stabilizing the locomotive's operating state, and improving the comfort of the driver and passengers.

[0063] In another specific embodiment, optionally, Figure 5 This invention provides a flowchart of another control method for a hybrid power source system for a locomotive with dual internal electric power sources. This embodiment refines the specific implementation of S120 in the above embodiment, which determines the target speed of the diesel engine based on the grid voltage and the total load of the locomotive, as follows:

[0064] Determine the first speed of the diesel engine based on the grid voltage;

[0065] The second speed of the diesel engine is determined based on the total load of the locomotive;

[0066] The maximum value between the first speed and the second speed is determined as the target speed of the diesel engine.

[0067] Furthermore, the specific implementation method for determining the target output power of the four-quadrant rectifier based on the total load of the locomotive and the target output power of the main generator in the above embodiment S130 is refined as follows:

[0068] Determine the total power requirement of the locomotive based on its total load;

[0069] The difference between the total power demand and the target output power of the main generator is determined as the target output power of the four-quadrant rectifier.

[0070] For details not covered in this embodiment, please refer to the above embodiments, which will not be repeated here.

[0071] refer to Figure 5 As shown, the method includes:

[0072] S210, Obtain the pantograph voltage and the total load of the locomotive.

[0073] S220. Determine the first speed of the diesel engine based on the grid voltage.

[0074] S230. Determine the second speed of the diesel engine based on the total load of the locomotive.

[0075] This step can be further broken down as follows: determine the total power demand of the locomotive based on its total load; and determine the second speed of the diesel engine based on the total power demand.

[0076] S240. Determine the maximum value between the first speed and the second speed as the target speed of the diesel engine, and control the diesel engine to reach the target speed.

[0077] Specifically, when determining the target speed of the diesel engine, the first speed of the diesel engine needs to be determined based on the real-time grid voltage of the pantograph. A certain preset relationship can exist between the pantograph and the first speed of the diesel engine; within a preset fluctuation range of the real-time grid voltage, the first speed of the diesel engine remains unchanged. Therefore, after obtaining the grid voltage, the first speed of the diesel engine corresponding to the real-time grid voltage of the pantograph can be determined. Simultaneously, the total power demand of the locomotive is determined based on the total load of the locomotive. The specific determination method may include, but is not limited to, establishing a preset correspondence or logical operations, etc., and is not restricted here. After determining the total power demand of the locomotive, the second speed of the diesel engine can be determined based on the total power demand, using a preset correspondence or logical operations, etc. After determining the first and second speeds of the diesel engine, the target speed of the diesel engine can be determined based on the first and second speeds. The specific determination method can be determined according to the actual situation, such as comparing magnitudes or determining through logical operations between the three, etc., and is not restricted here. In this embodiment, the maximum value of the first and second speeds is determined as the target speed of the diesel engine, and the diesel engine is controlled to reach this target speed.

[0078] S250. Based on the grid voltage and the total load of the locomotive, determine the target current of the excitation unit and control the excitation unit to reach the target current so that the main generator can reach the target output power.

[0079] S260. The difference between the total required power and the target output power of the main generator is determined as the target output power of the four-quadrant rectifier.

[0080] Specifically, after determining the total power demand of the load and the target output power of the main generator, the target output power of the four-quadrant rectifier can be obtained by subtracting the total power demand from the target output power of the main generator.

[0081] It should be noted that because the diesel engine power source has limitations such as combustion mechanism, its power load adjustment rate is slower than that of the overhead contact line power source. Therefore, when load or grid voltage changes occur, the overhead contact line power source module needs to make timely adjustments first. After the diesel engine power source module gradually matches the corresponding speed, output voltage, and power, the overhead contact line power source module will then make secondary adaptive adjustments. For example, when the locomotive needs to haul, the total load power increases from P1 to P1+ΔP, where ΔP is the power required for the haul load. If it is determined that the current voltage Ud1 across the supporting capacitor is insufficient to support the total load power P1+ΔP, then the four-quadrant rectifier is first controlled to increase its duty cycle, thereby increasing the input current of the overhead contact line and thus increasing the voltage Ud1 across the supporting capacitor. Simultaneously, the target speed n3+Δn of the diesel engine is calculated based on the total load power P1+ΔP, and the diesel engine speed is controlled to increase to n3+Δn. At the same time, the excitation current of the excitation unit in the diesel engine power source module is increased to improve the output power of the main generator. When the output power of the main generator reaches P2+ΔP, it indicates that the output power of the diesel engine power source module has reached the preset power. Then, the power difference is compensated by adjusting the four-quadrant rectifier in a secondary manner, that is, controlling the four-quadrant rectifier to reduce the duty cycle and reduce the input current, so that the output power of the four-quadrant rectifier reaches P3+ΔP, ensuring the stable operation of the load.

[0082] When the contact wire voltage increases but the total load power demand remains unchanged, the target diesel engine speed n3+Δn is calculated based on the matching relationship between the effective value of the contact wire voltage and the diesel engine speed. The diesel engine speed is then controlled to increase to n3+Δn, while the excitation current of the excitation unit is adjusted to increase the output voltage of the main generator to match the increased output voltage of the four-quadrant rectifier due to the increased contact wire voltage. When the main generator output power reaches the target output power, the four-quadrant rectifier is controlled to reduce its duty cycle and input current to ensure stable load operation.

[0083] The technical solution of this invention involves obtaining the pantograph's grid voltage and the locomotive's total load; determining the first speed of the diesel engine based on the grid voltage; determining the second speed of the diesel engine based on the locomotive's total load; determining the maximum value between the first and second speeds as the target speed of the diesel engine, and controlling the diesel engine to reach the target speed; determining the target current of the excitation unit based on the grid voltage and the locomotive's total load, and controlling the excitation unit to reach the target current, so that the main generator reaches the target output power; and determining the difference between the total required power and the main generator's target output power as the target output power of the four-quadrant rectifier. Using the above method, simultaneous mixed output from both the overhead contact line and the diesel engine is achieved, and stable operation of the load can still be ensured even with load fluctuations, improving the comfort and experience of the driver and passengers.

[0084] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0085] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A hybrid operating system for a locomotive power source with dual internal electric power sources, characterized in that, This includes the overhead contact line power source module, the diesel engine power source module, and the control module; The overhead contact line power source module includes an electrically connected pantograph and a four-quadrant rectifier; the diesel engine power source module includes a mechanically connected diesel engine, a main generator, and an excitation unit electrically connected to the main generator; the four-quadrant rectifier and the main generator are electrically connected to the locomotive load, and the control module is electrically connected to the pantograph, the four-quadrant rectifier, the diesel engine, the excitation unit, and the load, respectively. The control module is used to acquire the grid voltage of the pantograph and the total load of the locomotive, determine the target speed of the diesel engine and the target current of the excitation unit based on the grid voltage and the total load of the locomotive, and control the diesel engine to reach the target speed and the excitation unit to reach the target current, so that the main generator can reach the target output power. The target output power of the four-quadrant rectifier is determined based on the total load of the locomotive and the target output power of the main generator.

2. The hybrid operating system of internal electric dual-source locomotive power source according to claim 1, characterized in that, It also includes a support capacitor; the input terminal of the support capacitor is electrically connected to the four-quadrant rectifier and the main generator respectively, and the output terminal of the support capacitor is electrically connected to the load; The supporting capacitor is used to ensure the stable output of the overhead contact line power from the four-quadrant rectifier and the diesel engine power from the main generator.

3. The hybrid operating system of internal electric dual-source locomotive power source according to claim 2, characterized in that, It also includes an inverter unit; the inverter unit is electrically connected between the supporting capacitor and the load.

4. The hybrid operating system of internal electric dual-source locomotive power source according to claim 1, characterized in that, The overhead contact line power source module also includes a main circuit breaker and a traction transformer; The main circuit breaker and the traction transformer are sequentially electrically connected between the pantograph and the four-quadrant rectifier.

5. The hybrid operating system of internal electric dual-source locomotive power source according to claim 1, characterized in that, The diesel engine power source module also includes a three-phase uncontrolled rectifier; The three-phase uncontrolled rectifier is electrically connected between the main generator and the load.

6. The hybrid working system of internal electric dual-source locomotive power source according to claim 1, wherein the control module is further configured to determine the first speed of the diesel engine according to the grid voltage; determine the second speed of the diesel engine according to the total load of the locomotive; and determine the target speed of the diesel engine according to the first speed and the second speed.

7. A control method for a hybrid operating system of dual-power locomotive systems, characterized in that, The method, applied to the hybrid working system of internal electric dual-source locomotive power source according to any one of claims 1-6, comprises: Obtain the grid voltage of the pantograph and the total load of the locomotive; Based on the grid voltage and the total load of the locomotive, the target speed of the diesel engine and the target current of the excitation unit are determined, and the diesel engine is controlled to reach the target speed and the excitation unit to reach the target current, so that the main generator can reach the target output power; The target output power of the four-quadrant rectifier is determined based on the total load of the locomotive and the target output power of the main generator.

8. The control method according to claim 7, characterized in that, Determining the target speed of the diesel engine based on the grid voltage and the total load of the locomotive includes: The first speed of the diesel engine is determined based on the grid voltage; The second speed of the diesel engine is determined based on the total load of the locomotive; The maximum value between the first speed and the second speed is determined as the target speed of the diesel engine.

9. The control method according to claim 8, characterized in that, Determining the second speed of the diesel engine based on the total load of the locomotive includes: The total power demand of the locomotive is determined based on its total load. The second speed of the diesel engine is determined based on the total required power.

10. The control method according to claim 7, characterized in that, The target output power of the four-quadrant rectifier is determined based on the total load of the locomotive and the target output power of the main generator, including: The total power demand of the locomotive is determined based on its total load. The difference between the total required power and the target output power of the main generator is determined as the target output power of the four-quadrant rectifier.

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