Hybrid power mining truck energy coordination control method and system

Abstract

The invention relates to an energy coordination control method and system for a hybrid power mining truck. The method comprises the following steps that the working mode of the truck is determined based on the circulating working condition of a mining area; obtaining intention information of a driver; calculating a traction power or a braking power based on the driver intent; distribution is carried out based on the corresponding working mode, the engine demand power and the DCDC converter demand power are determined, and a charging and discharging command is generated; and performing energy coordination control on the generator set and the DCDC converter based on the distributed demand power. According to the method, the vehicle circulation working condition, the working modes and the intention of a driver are comprehensively considered, the traction power or the braking power is distributed through the corresponding distribution strategies under the different vehicle working modes, and energy coordination control is conducted on the generator set and the DCDC converter; and efficient, stable and dynamic energy collaborative management between the hybrid power mining truck generator set and the power battery is realized.

Description

Technical Field

[0001] This invention belongs to the field of rail vehicle technology, and particularly relates to a method and system for coordinated energy control of hybrid mining trucks. Background Technology

[0002] Open-pit mining is a crucial method for extracting various mineral resources, including coal, iron ore, copper ore, and aggregates. Currently, transportation equipment in open-pit mines primarily consists of mining trucks powered by large diesel engines. While these trucks have high load-bearing capacity, they are inefficient under low-speed, high-load conditions, such as when fully loaded uphill. On empty return trips, the engine load rate is low, resulting in poor overall fuel economy. Furthermore, these trucks have large displacements and low combustion thermal efficiency, leading to significant carbon emissions and severe environmental pollution.

[0003] In existing technologies, hybrid technology has been widely applied in passenger cars and commercial vehicles, with hybrid models effectively improving fuel economy and reducing carbon emissions. However, for large mining trucks, on the one hand, they operate on harsh off-highway conditions, with heavy loads, large gradients, severe vibrations and shocks, short transport distances, and repetitive routes, operating 24 / 7 year-round—significantly different from the on-road application scenarios of passenger cars and commercial vehicles. On the other hand, mining trucks have megawatt-level drive power and system voltage levels approaching 2000V, far exceeding the power and voltage levels of ordinary vehicles. Therefore, the existing hybrid power system topologies, power device selection, and control strategies developed based on passenger cars and commercial vehicles cannot be directly applied to ultra-large mining trucks. Summary of the Invention

[0004] The purpose of this invention is to solve one of the above-mentioned technical problems and to provide a method and system for coordinated energy control of hybrid mining trucks.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for coordinated energy control of a hybrid mining truck includes the following steps: The vehicle's cyclic operating conditions in the mining area are obtained, and the vehicle's working mode is determined based on the cyclic operating conditions; the working mode includes at least traction mode and braking mode. Acquire driver intent information, including the travel distance of the accelerator pedal and the travel distance of the brake pedal; In traction mode, the corresponding traction power is calculated based on the accelerator pedal travel, and the traction power is allocated based on a predetermined allocation strategy to determine the engine power requirement and the DC-DC converter power requirement, and to generate charging and discharging commands. In braking mode, the corresponding braking power is calculated based on the brake pedal travel and opening, and the power required by the DC-DC converter is determined based on the braking power, generating charging and discharging commands. Energy coordination control of the engine unit is performed based on the engine's required power; energy coordination control of the DC-DC converter is performed based on the DC-DC converter's required power and charge / discharge commands.

[0006] In some embodiments of the present invention, the method for energy coordination control of the engine pack based on engine power demand specifically includes the following steps: A generator set control model is established based on the vehicle's engine universal characteristic curve and generator speed-voltage curve to adaptively adjust and control the generator set's speed, excitation, voltage, and power. Based on the engine's power demand and the engine's optimal fuel economy curve, the generator sets are controlled in stages to determine the number of generator sets connected and the output power of a single generator set. When the number of generator sets connected is greater than or equal to two, a droop control strategy is introduced to perform power balance control on each connected generator set.

[0007] In some embodiments of the present invention, the method for establishing a generator set control model includes the following steps: Obtain the universal characteristic curve of the vehicle's engine, and determine the engine speed-power curve based on the universal characteristic curve; Obtain the generator speed-voltage curve of the vehicle, and perform adaptive excitation adjustment based on the generator speed-voltage curve; An adaptive regulation system for the generator set is established based on the engine speed-power curve and the generator speed-voltage curve. The adaptive regulation system is used to adaptively regulate and control the speed, excitation, voltage and power of the generator set.

[0008] In some embodiments of the present invention, the method for adaptively regulating and controlling the speed, excitation, voltage, and power of a generator set includes the following steps: When the engine is woken up, the engine speed is determined by looking up a table based on the vehicle's engine universal characteristic curve. The generator output voltage is determined based on the generator speed-voltage curve of the vehicle. The duty cycle of the generator excitation controller is determined based on voltage-current dual closed-loop PI regulation.

[0009] In some embodiments of the present invention, the method for power balance control of each connected generator set by introducing a droop control strategy includes the following steps: Detect the voltage imbalance difference between each generator set; The voltage imbalance difference is multiplied by a predetermined first modulation factor as the voltage droop modulation factor. By applying the droop modulation coefficient to the given value of the excitation current, closed-loop control of generator power balance is achieved.

[0010] In some embodiments of the present invention, the method for energy coordination control of a DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter includes the following steps: Distribute the power demand of the DC-DC converters evenly among the DC-DC converters. In DCDC current mode, the power allocated to each DCDC converter is converted into the target charging and discharging current in conjunction with the charging and discharging commands. The power of each DC-DC converter is monitored in real time, and a droop control strategy is introduced to adjust the target current of each DC-DC converter in real time to achieve dynamic balance of power of each DC-DC converter.

[0011] In some embodiments of the present invention, the method for energy coordination control of a DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter includes the following further steps: Based on charge and discharge commands, the automatic charge and discharge switching control of the DC-DC converter is achieved by controlling the target current to smoothly cross zero. During the switching process, hysteresis is set in the zero-crossing region to eliminate the influence of sampling bias.

[0012] In some embodiments of the present invention, the method for real-time adjustment of the target current of each DC-DC converter by introducing a droop control strategy includes the following steps: Detect the current imbalance difference between each DC-DC converter; The result of multiplying the current imbalance difference by a predetermined second modulation coefficient is used as the current droop modulation coefficient; By applying the current droop modulation coefficient to the given value of the target current of the DC-DC converter, closed-loop control of the power balance of the DC-DC converter is achieved.

[0013] In some embodiments of the present invention, the predetermined allocation strategy is an optimal power allocation strategy determined based on operating mode characteristic data and power source characteristic data; allocating traction power based on the predetermined allocation strategy further includes the following steps: Extract operating mode feature data, which includes traction power demand under each operating mode; Extract power source feature data; power source feature data includes battery feature data and engine feature data; Based on the traction power demand, battery characteristic data, and engine characteristic data under the current operating mode, the battery participation strategy is adjusted to achieve optimal power allocation for traction.

[0014] In some embodiments of the present invention, the operating mode further includes a vehicle charging mode; the energy coordination control method further includes the following steps: In driving charging mode, when the predetermined charging conditions are met, the generator's power demand is updated to the sum of the traction power and the DC-DC converter's power demand.

[0015] In some embodiments of the present invention, the operating mode further includes an idle / stop mode; the energy coordination control method further includes the following steps: In idle / stop mode, the engine power demand is made equal to the DC-DC converter power demand.

[0016] Some embodiments of the present invention further provide a hybrid mining truck energy coordination control system for implementing the above-described hybrid mining truck energy coordination control method, including a total energy coordination controller, a generator set energy coordination controller, and a DC-DC energy coordination controller; The total energy coordination controller includes a mining area cycle operating condition model, a driver intention model, and an energy management model; The mining area cyclic operating condition model is used to obtain the cyclic operating conditions of vehicles in the mining area and to determine the working mode of the vehicles based on the cyclic operating conditions. The driver intent model is used to obtain driver intent information, which includes the travel distance of the accelerator pedal and the travel distance of the brake pedal. The energy management model is used to calculate the corresponding traction power or braking power based on driver intention information, and allocate the traction power or braking power based on the current vehicle operating mode; determine the corresponding engine power demand, DC-DC converter power demand, and charging / discharging commands; The generator set energy coordination controller is used to coordinate and control the energy of the generator set based on the engine's power demand. The DC-DC energy coordination controller is used to perform energy coordination control of the DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter.

[0017] The beneficial effects of this invention are as follows: 1. This invention comprehensively considers various cyclic operating conditions, vehicle working modes, and driver intentions. Based on the driver's intentions, it calculates traction power or braking power and allocates traction power or braking power through corresponding allocation strategies under different vehicle working modes. It determines the engine power demand and DC-DC converter power demand and performs energy coordination control on the generator set and DC-DC converter, realizing efficient, stable, and dynamic energy collaborative management between the hybrid mining truck generator set and the power battery. 2. This invention establishes an adaptive model based on universal characteristics and generator speed-voltage curves, enabling the generator set to always operate in the high-efficiency range, significantly improving fuel thermal efficiency; at the same time, hierarchical access control avoids prolonged inefficient operation of the generator set, further improving the overall energy efficiency of the system. 3. This invention ensures the safe and reliable transmission of large current on the battery side by controlling the current sharing of multiple DC-DC converters. At the same time, by setting a charging and discharging switching mechanism, it improves the smoothness of the vehicle's power response and can adapt to the working characteristics of mining trucks that frequently start and stop, accelerate and decelerate. 4. This invention introduces a droop control strategy in the energy coordination control process of the generator set and the DC-DC converter, realizing closed-loop regulation of power balance between the generator set and the DC-DC converter.

[0018] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A schematic diagram of an energy coordination control method for a hybrid mining truck; Figure 2 A schematic diagram of the main circuit topology of a hybrid mining truck provided in an embodiment of the present invention; Figure 3 A schematic diagram of the cyclic working conditions in a mining area provided in an embodiment of the present invention; Figure 4 A schematic diagram of an energy coordination control method for a hybrid mining truck; Figure 5 A schematic diagram of the working process of the total energy coordination controller provided in an embodiment of the present invention; Figure 6 A schematic diagram illustrating the workflow of the generator set energy coordination controller provided in an embodiment of the present invention; Figure 7 A schematic diagram illustrating the workflow of the DC-DC energy coordination controller provided in an embodiment of the present invention; Figure 8 A schematic diagram of the driver's intent acquisition process provided in an embodiment of the present invention; Figure 9 This is a schematic diagram of the workflow of the adaptive adjustment system provided in an embodiment of the present invention; Figure 10 This is a schematic diagram of the control strategy for a DC-DC converter provided in an embodiment of the present invention. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the application is described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0022] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations according to this application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. Furthermore, it should be understood that 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 process, method, product, or apparatus.

[0023] In the field of mineral extraction, open-pit mining plays a vital role in the development of various mineral resources such as coal, iron ore, copper ore, and aggregates due to its advantages of large-scale production, low production costs, high safety, and good economic benefits. Taking coal as an example, open-pit mining accounts for more than 40% of the global total. In countries such as the United States, Russia, and Australia, open-pit coal mines account for more than 70%, while in countries such as Mongolia, Indonesia, and Kazakhstan, open-pit coal mines account for more than 90%.

[0024] my country is a major coal producer and consumer. Open-pit coal mines are concentrated in Inner Mongolia, Xinjiang, Shanxi, Yunnan and other places. There are currently 357 open-pit coal mines in my country, including 40 open-pit coal mines with an annual output of more than 10 million tons. The annual production capacity of open-pit coal mines is 1.162 billion tons, accounting for 25% of the country's total coal production, and the proportion continues to increase.

[0025] The vast market has spurred a significant demand for large-scale open-pit mining equipment. Currently, most mainstream mining trucks are driven by large-displacement diesel engines. While these engines have strong load-bearing capacity, they suffer from low speeds when heavily loaded uphill and low load rates when returning unloaded, resulting in poor fuel economy. Furthermore, the large displacement and low thermal efficiency of these trucks lead to substantial carbon emissions, exacerbating environmental pollution.

[0026] In an era focused on green environmental protection and cost reduction, developing new types of mining trucks has become an inevitable trend in the industry. Furthermore, due to the inherent limitations of pure electric vehicles in terms of range and the insufficient energy efficiency and environmental friendliness of pure gasoline vehicles, high-performance hybrid systems are considered a crucial direction for the future development of mining trucks.

[0027] In existing technologies, hybrid power technology has been widely applied in passenger and commercial vehicles, achieving significant economic and social benefits. However, its application in ultra-large mining trucks remains in the development and testing phase. On the one hand, mining trucks operate in harsh environments, carrying heavy loads, experiencing significant gradient changes, and subjected to intense vibration and impact. They also require short-distance, continuous, and uninterrupted operation, which is drastically different from the operating scenarios of highway vehicles. On the other hand, mining trucks have megawatt-level drive power and system voltages approaching 2000V, far exceeding the power and voltage levels of ordinary vehicles. Therefore, the electrical architecture, power devices, and control strategies used in passenger and commercial vehicles are difficult to directly apply to ultra-large mining trucks.

[0028] Based on the above application scenarios, this application proposes an energy coordination control method for hybrid mining trucks.

[0029] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0030] The technical solution of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings.

[0031] As attached Figure 1 -Appendix Figure 10 As shown, in an illustrative embodiment of the energy coordination control method for a hybrid mining truck according to the present invention, the control method is applied to a hybrid mining truck energy coordination control system that includes at least a total energy coordination controller A1, a generator set energy coordination controller B1, and a DC-DC energy coordination controller B2.

[0032] The hybrid mining truck is a rigid mining truck, and its main circuit topology is as follows: Figure 2 As shown, it includes equipment such as an engine, generator, rectifier, power battery, DC-DC converter, traction inverter, chopper, motor, and braking resistor.

[0033] The diesel generator set includes three diesel engines and a coaxially driven alternator, which are rigidly connected by a rotating shaft. The diesel engines drive the generator to produce three-phase alternating current. The diesel generator set is controlled by a generator set energy coordination controller B1.

[0034] The power battery pack consists of two sets of power batteries, with the battery voltage being direct current. The power battery pack is controlled by a BMS (Battery Management System).

[0035] Two AC motors are mounted on the two rear drive wheels of the mining truck, serving as the actuators for traction and electric braking of the entire vehicle. They are connected to the traction inverter via high-voltage cables to provide traction and braking force to the vehicle. The braking resistor is a safety device that rapidly releases energy when the bus voltage exceeds a set threshold during braking; it is connected to a chopper via a high-voltage cable.

[0036] The converter module includes a rectifier, a DC-DC converter, a traction inverter, and a chopper. Three rectifiers correspond to three diesel generator sets, connected via high-voltage cables, rectifying the three-phase AC power into high-voltage DC power, which is then fed into the high-voltage DC bus. The rectifiers are uncontrolled and require no controller. Two DC-DC converters correspond to two sets of power batteries. Due to the potential difference between the battery voltage and the high-voltage DC bus voltage, the DC-DC converters function as step-up / step-down converters and control the charging / discharging power. When the battery discharges, the DC-DC converter boosts the battery voltage to the high-voltage DC bus voltage for discharging; when the battery charges, the DC-DC converter steps down the high-voltage DC bus voltage to the battery voltage for charging. The DC-DC converter is controlled by the DC-DC energy coordination controller B2. The traction inverter inverts the high-voltage DC bus voltage into three-phase AC power with adjustable voltage and frequency, controlling the AC motor to generate traction force for the vehicle, or rectifies the three-phase AC power generated during regenerative braking of the AC motor into high-voltage DC power, which is then fed back to the battery via the DC-DC converter for energy recovery. When the chopper is used for regenerative braking, if the bus voltage exceeds a set threshold, the chopper controls the braking resistor to connect for rapid energy release. The traction inverter and chopper are controlled by the traction controller.

[0037] The energy coordination and control method includes the following steps.

[0038] S1: Determine the vehicle's operating mode based on the mining area's cyclical operating conditions; calculate traction power or braking power based on the driver's intention; allocate traction power or braking power according to the corresponding allocation strategy under different vehicle operating modes, determine the engine's required power and the DC-DC converter's required power, and generate charging and discharging commands.

[0039] Step S1 specifically includes the following steps: S11: Establish a mining area cyclic operating condition model in the total energy coordination controller A1 to obtain the cyclic operating conditions of the vehicle in the mining area and determine the vehicle's operating mode based on the cyclic operating conditions. The operating mode includes at least traction mode and braking mode.

[0040] Specifically, the method for determining the vehicle's working mode using the mining area cyclic working condition model in step S11 includes the following steps.

[0041] A navigation system is used to create a route map of the mining area to obtain information such as the route length and altitude of each section of the road, and to establish an information database. In this embodiment, the navigation system used is the Global Positioning System (GPS).

[0042] Based on path length and altitude, the various sections of the mining area are divided into characteristic sections such as uphill, flat, and downhill.

[0043] like Figure 3 As shown, vehicle load information is obtained through an on-board weighing system, and based on this information, five main cyclical working conditions (States) are further divided: fully loaded flat road, fully loaded uphill, empty flat road, empty downhill, and loading / unloading waiting. It should be understood that during vehicle operation in the mining area, the system can switch between characteristic segments in real time based on real-time data from slope sensors, and can also switch between cyclical working conditions in real time by combining this with vehicle load information.

[0044] By conducting vehicle tests, the switching conditions of each cycle state in the established mining area cycle working condition model are corrected, thereby achieving model correction.

[0045] During the switching of the five operating states, the vehicle's operating mode is switched according to the required power and vehicle speed.

[0046] The vehicle's operating modes include, but are not limited to, traction mode, braking mode, driving-charging mode, and idle / stop mode. Traction mode includes pure engine mode, single-engine hybrid mode, and three-engine hybrid mode. The braking mode is specifically regenerative braking mode.

[0047] S12: Establish a driver intention model in the total energy coordination controller A1 to obtain driver intention information and calculate traction power or braking power.

[0048] Driver intent information includes the travel of the accelerator pedal and the travel of the brake pedal.

[0049] Specifically, the method for obtaining driver intent information and calculating traction power or braking power in step S12 includes the following steps.

[0050] Obtain gear information. Gear information includes forward, reverse, and parking directions.

[0051] Based on the accelerator pedal's travel distance and duration, the driver's intention is determined, and the traction torque Te_tra and corresponding traction power P_tra are calculated.

[0052] Based on the brake pedal's depressor travel and duration, the driver's intention is determined, and the real-time braking torque Te_bra and corresponding braking power P_bra are calculated.

[0053] S13: Establish an energy management model in the total energy coordination controller A1 to allocate the required power to the generator set and DC-DC converter based on the vehicle's operating mode and traction or braking power.

[0054] Specifically, in traction mode, traction power is allocated based on a predetermined allocation strategy, the required power of the engine and the required power of the DC-DC converter are determined, and charging and discharging commands are generated.

[0055] In braking mode, with the engine idling, the power demand of the DC-DC converter is determined based on the braking power, and a charging / discharging command is generated.

[0056] In driving charging mode, when the predetermined charging conditions are met, the generator's power demand is updated to the sum of the traction power and the DC-DC converter's power demand.

[0057] In idle / stop mode, the engine power demand is made equal to the DC-DC converter power demand.

[0058] S2: Energy coordination control of the engine group based on the engine's required power.

[0059] S3: Perform energy coordination control on the DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter.

[0060] In the above illustrative embodiments, by constructing a dual decision-making framework based on the mining area's cyclical operating conditions and the real-time driver's intentions, efficient, stable, and dynamic energy collaborative management between the hybrid mining truck's generator set and the power battery is achieved.

[0061] In some embodiments of the present invention, the matching relationship between the five cyclic operating conditions and the six vehicle operating modes is as follows.

[0062] Fully loaded uphill condition: This condition has the highest power demand of the vehicle in the five cycles, and the total energy coordination controller A1 intelligently schedules the vehicle to enter the three-engine hybrid mode.

[0063] Under full load uphill conditions and in three-engine hybrid mode, the vehicle's three diesel generator sets work simultaneously, and both DC-DC converters are in a discharging state. The five power sources provide traction power simultaneously, maximizing the traction power to meet the vehicle's power requirements when fully loaded uphill.

[0064] Fully loaded flat road condition: In this condition, the vehicle's power demand is relatively high during the five cycles of the operating condition, requiring it to enter either single-engine hybrid mode or pure engine mode. At this time, based on the remaining battery charge (State of Charge, SOC) status, the total energy coordination controller A1 intelligently schedules the vehicle to enter either hybrid mode or pure engine mode.

[0065] Under full-load, flat-road conditions and in single-engine hybrid mode, only one engine operates, while both DC-DC converters are in a discharged state. This is suitable for applications with a high battery SOC. The total energy coordination controller A1 allocates the power demand from the engine and the DC-DC converter. Based on the allocated engine power demand, the generator set energy coordination controller B1 intelligently selects to operate only one diesel generator set, resulting in better economy and lower fuel consumption.

[0066] Under full load on flat roads and in pure engine mode, all three engines operate simultaneously, with neither of the two DC-DC converters participating in power output (standby state, neither charging nor discharging). This is suitable for areas with low remaining battery power. The total energy coordination controller A1 allocates all required power to the engines. The generator set energy coordination controller B1 intelligently selects which of the three engines to operate simultaneously based on the allocated engine power.

[0067] Unloaded flat road condition: In this condition, the vehicle's power demand is relatively low compared to the other two cycles, requiring the vehicle to enter either pure engine mode or driving charging mode. At this time, based on the remaining battery charge, the total energy coordination controller A1 intelligently schedules the vehicle to enter either pure engine mode or driving charging mode.

[0068] In no-load, flat road conditions and pure engine mode, the total energy coordination controller A1 allocates all the required power to the engine. The generator set energy coordination controller B1 intelligently selects whether only one or two diesel generator sets work based on the allocated engine power. Neither of the two DC-DC converters participates in power output (standby state, neither charging nor discharging), which is suitable for ranges with high remaining battery power.

[0069] No-load flat road condition and driving charging mode: suitable for areas with low battery remaining power. The total energy coordination controller A1 intelligently monitors that the battery remaining power is low and the engine power is sufficient. At this time, the power demand and the power required for DC-DC charging are allocated to the engine. The generator set energy coordination controller B1 intelligently selects to operate only two or three diesel generator sets according to the allocated engine power, and both DC-DC converters are in charging state.

[0070] No-load downhill condition: In this condition, the vehicle has no power demand in the five cycle conditions, and energy recovery from downhill braking will occur, requiring the vehicle to enter regenerative braking mode.

[0071] Under no-load downhill conditions and regenerative braking mode, the total energy coordination controller A1 intelligently allocates the charging power to the DC-DC energy coordination controller B2. At this time, the engine is idling and does not participate in power output, and both DC-DC converters are in energy recovery state.

[0072] Loading / unloading waiting condition: In this condition, the vehicle has no power requirement and is stationary, waiting to load or unload materials. The vehicle will enter idle / stop mode.

[0073] During loading / unloading waiting conditions and in idle / stop mode, if the total energy coordination controller A1 intelligently monitors and detects that the remaining battery charge is low, it will initiate idle charging, with the engine providing the charging power to the battery. The total energy coordination controller A1 will then distribute the required power to the generator set energy coordination controller B1 and the charging power to the DC-DC converter energy coordination controller B2. If the total energy coordination controller A1 intelligently monitors and detects that the remaining battery charge is high, it will initiate a shutdown, i.e., the engine will idle and the DC-DC converter will be in standby mode (neither charging nor discharging).

[0074] In some embodiments of the present invention, the method for energy coordination control of the engine pack based on the engine's required power specifically includes the following steps.

[0075] S21: Establish a generator set control model based on the vehicle's engine universal characteristic curve and generator speed-voltage curve, which is used to adaptively adjust and control the generator set's speed, excitation, voltage, and power.

[0076] S22: Based on the engine's power demand and the engine's optimal fuel economy curve, the generator sets are controlled in stages to determine the number of generator sets connected and the output power of each generator set.

[0077] S23: When the number of generator sets connected is greater than or equal to two, a droop control strategy is introduced to perform power balance control on each connected generator set.

[0078] It should be noted that due to differences in individual generator characteristics, power imbalances may occur between different generator sets. Specifically, the essence of power imbalance among generator sets is an imbalance in their output voltage. This power imbalance is monitored by tracking the output voltage deviation. Therefore, in step S23, a droop control strategy is introduced to perform power balance control on each connected generator set. The output voltage deviation is converted into an excitation current setpoint deviation, and the excitation current setpoint is adjusted online in real time. By precisely adjusting the excitation current, the output voltage balance of the generator sets is controlled, thereby achieving dynamic equalization control of the output power.

[0079] In some embodiments of the present invention, the method for establishing a generator set control model in step S21 includes the following steps.

[0080] Obtain the universal characteristic curve of the vehicle's engine, and determine the engine speed-power curve based on the universal characteristic curve.

[0081] Obtain the generator speed-voltage curve of the vehicle, and perform excitation adaptive adjustment based on the generator speed-voltage curve.

[0082] An adaptive regulation system for the generator set is established based on the engine speed-power curve and the generator speed-voltage curve. The adaptive regulation system is used to adaptively regulate and control the speed, excitation, voltage and power of the generator set.

[0083] In some embodiments of the present invention, such as Figure 9 As shown, the method for adaptively adjusting and controlling the speed, excitation, voltage and power of the generator set in step S21 includes the following steps.

[0084] When the engine is woken up, the engine speed is determined by looking up a table based on the vehicle's engine universal characteristic curve.

[0085] The generator output voltage is determined based on the generator speed-voltage curve of the vehicle.

[0086] The duty cycle of the generator excitation controller is determined based on voltage-current dual closed-loop PI regulation.

[0087] In some embodiments of the present invention, step S22 specifically includes the following steps.

[0088] Based on the engine's optimal fuel economy curve, the output power range of a single generator set is determined, thereby clarifying the output power range of the entire generator set.

[0089] The number of generator sets to be connected is determined based on the location of the generator power demand interval.

[0090] Based on the number of generator sets connected, the output power of a single generator set is determined.

[0091] In some embodiments of the present invention, step S23, the method of introducing a droop control strategy to perform power balance control on each connected generator set, includes the following steps.

[0092] Detect the voltage imbalance difference between each generator set.

[0093] The voltage imbalance difference is multiplied by a predetermined first modulation factor, and the result is used as the voltage droop modulation factor.

[0094] By applying the droop modulation coefficient to the given value of the excitation current, closed-loop control of generator power balance is achieved.

[0095] In some embodiments of the present invention, the method for energy coordination control of a DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter includes the following steps.

[0096] S31: Distribute the power demand of the DC-DC converters evenly to each DC-DC converter.

[0097] In DC-DC current mode, the power allocated to each DC-DC converter is converted into the target charging / discharging current in conjunction with charge / discharge commands. In practical applications, the sign of the target current indicates the direction of charging / discharging.

[0098] S32: Real-time monitoring of the power of each DC-DC converter, and introduction of droop control strategy to adjust the target current of each DC-DC converter in real time, so as to achieve dynamic balance of the power of each DC-DC converter.

[0099] It should be noted that due to differences in sampling and device characteristics of DC-DC converters, there may be a power imbalance between the two DC-DC converters under the same target current. Therefore, in step S32, droop control is introduced by monitoring the power of the two DC-DC converters to adjust the target current value in real time, thereby achieving dynamic power balance between the two DC-DC converters.

[0100] Because DC-DC converters involve frequent charge-discharge switching under different transportation conditions, they need to respond quickly. In some embodiments of the present invention, the method for energy coordination control of DC-DC converters based on the power demand and charge-discharge commands of the DC-DC converter includes the following further steps.

[0101] S33: Based on charge and discharge commands, the DCDC converter can be automatically switched between charge and discharge by controlling the target current to smoothly cross zero, without the need for shutdown.

[0102] During the switching process, hysteresis is set in the zero-crossing region to eliminate the influence of sampling bias and prevent frequent switching.

[0103] In some embodiments of the present invention, such as Figure 10 As shown, in step S32, the method of introducing a droop control strategy to adjust the target current of each DC-DC converter in real time includes the following steps.

[0104] Detect the current imbalance difference between each DC-DC converter.

[0105] The result of multiplying the current imbalance difference by a predetermined second modulation coefficient is used as the current droop modulation coefficient.

[0106] By applying the current droop modulation coefficient to the given value of the target current of the DC-DC converter, closed-loop control of the power balance of the DC-DC converter is achieved.

[0107] In some embodiments of the present invention, the predetermined allocation strategy is an optimal power allocation strategy determined based on operating mode characteristic data and power source characteristic data.

[0108] Allocating traction power based on a predetermined allocation strategy further includes the following steps.

[0109] Vehicle operating mode characteristic data is extracted based on GPS data and vehicle data records. The operating mode characteristic data includes the traction power demand in each operating mode.

[0110] Specifically, in this embodiment, under heavy-load flat road conditions, the maximum traction power demand is Ps1, the energy consumption is Ws1, the duration of the condition is Ts1, and the average traction power demand is Psa1, where Psa1 = Ws1 / Ts1. It should be noted that in this application, energy consumption is a unified variable; a positive sign represents energy consumption, and a negative sign represents energy recovery.

[0111] Under heavy-load uphill conditions, the maximum traction power demand Ps2, energy consumption Ws2, duration of operation Ts2, and average traction power demand Psa2 are calculated.

[0112] Under no-load downhill conditions, the maximum traction power demand Ps3, energy consumption Ws3, duration of operation Ts3, and average traction power demand Psa3 are calculated.

[0113] Under no-load flat road conditions, the maximum traction power demand is Ps1, the energy consumption is Ws4, the duration of the condition is Ts4, and the average traction power demand is Psa4.

[0114] Under loading and unloading waiting conditions, the maximum traction power demand is Ps5, the energy consumption is Ws5, the duration of the condition is Ts5, and the average traction power demand is Psa5.

[0115] Based on the above, the total power consumption under cyclic conditions can be calculated: Ws = Ws1 + Ws2 + Ws3 + Ws4 + Ws5.

[0116] Extract power source characteristic data. This power source characteristic data includes battery characteristic data and engine characteristic data.

[0117] Specifically, in this embodiment, the battery characteristic data includes: the battery's high-efficiency remaining capacity range, [SOC_L, SOC_H]; battery capacity Q_bs; and total usable battery capacity W_bs. Where W_bs = Q_bs * (SOC_H - SOC_L). The maximum total continuous discharge power of the DC-DC converter is P_dcm; the maximum total continuous discharge power of the battery is P_btm; and the effective maximum total continuous discharge power of the battery is P_bs. Where P_bs = min(P_dcm, P_btm).

[0118] Engine characteristic data includes the maximum power P_Ms of a single engine in the high-efficiency range.

[0119] Based on the traction power demand, battery characteristic data, and engine characteristic data under the current operating mode, the battery participation strategy is adjusted to achieve optimal power allocation for traction.

[0120] Specifically, in this embodiment, under heavy-load flat road conditions, the working mode needs to meet the power requirements of the heavy-load flat road stage. The total power demand in this stage is moderate. By adjusting the number of engines, the high efficiency range of the engines can be fully utilized, and the battery does not participate in the power output.

[0121] The condition for entering the working mode is Psa4 < required power P_tra ≤ Psa1.

[0122] The power allocation code is: P_dcdc=0; Cmd_dcdc=0; / / DC-DC charging and discharging command, 0 means no charging or discharging; P_engine=P_tra.

[0123] Under heavy-load uphill conditions, the operating mode needs to meet the high power demand during the heavy-load uphill phase. During this phase, the engine operates under heavy load for a long time, exceeding its high-efficiency range. By using the battery to participate in the power output, the power can be significantly enhanced while keeping the engine's output power within its high-efficiency range. It also needs to meet the rapid acceleration requirements on both heavy-load and unloaded flat roads, providing sufficient power and rapid acceleration to respond to the driver's intentions. Furthermore, it needs to meet the needs of getting out of potholes due to uneven road surfaces, providing sufficient power for quick extrication and responding to the driver's intentions.

[0124] The condition for entering the working mode is that the required power P_tra > Psa1.

[0125] The power allocation code is: P_dcdc=P_bs; Cmd_dcdc=1; / / DC-DC charging and discharging command, 1 indicates discharging; P_engine=P_tra-P_dcdc.

[0126] Under no-load downhill conditions, the operating mode must meet the requirement of regenerative braking during the no-load downhill phase to recover energy and charge the battery. During this phase, the engine does not participate in power output.

[0127] The operating mode is entered when the required power P_tra < -Plim. Here, Plim is the minimum power setting threshold to prevent accidental switching when the required power is near zero.

[0128] The power allocation code is: P_dcdc=P_bs; Cmd_dcdc=-1; / / DC-DC charging and discharging command, -1 indicates charging; P_engine=0.

[0129] Under no-load flat road conditions, the working mode meets the power requirements of the no-load flat road stage. The total power demand in this stage is relatively small. By adjusting the number of engines, the high efficiency range of the engines can be fully utilized, and the battery does not participate in power output. When the battery SOC is low, the battery is charged while driving. By adjusting the number of engines, the engines can still be kept in the high efficiency range.

[0130] The condition for entering the working mode is Plim < required power P_tra ≤ Psa4.

[0131] The power allocation code is: If (SOC < SOC_set_L) / / Battery level is less than the vehicle charging set value { P_dcdc=P_bs; Cmd_dcdc=-1; / / DC-DC charging and discharging command, -1 indicates charging P_engine = P_tra + P_dcdc; } Else / / Battery capacity is greater than or equal to the vehicle charging setting value { P_dcdc=0; Cmd_dcdc=0; / / DC-DC charging and discharging command, 0 means no charging or discharging. P_engine=P_tra; }

[0132] During loading and unloading waiting conditions, the operating mode must meet the requirement of charging the battery while the battery SOC is low.

[0133] The condition for entering the working mode is -Plim≤Demand power P_tra≤Plim.

[0134] The power allocation code is: If (SOC < SOC_set_L) / / Battery charge is less than the idle charging setting value { P_dcdc=P_bs; Cmd_dcdc=-1; / / DC-CDC charge / discharge command, -1 indicates charging; P_engine=P_dcdc; } Else / / Battery charge is greater than or equal to the idle charging setting; { P_dcdc=0; Cmd_dcdc=0; / / DC-CDC charge / discharge command, 0 means no charging or discharging; P_engine=0;}

[0135] In a specific embodiment of the present invention, the power configuration schemes of the generator set and DC-DC converter for mining trucks with different total weights and loads are shown in Table 1.

[0136] Table 1 Power Configuration Table for Mining Trucks

[0137] Taking a 330-ton load capacity as an example, the total power of a mining truck equipped with three 16-liter small diesel engines and a power battery is 2690kW. Compared with the traditional single-engine pure oil mining truck with a single 80-liter displacement engine and a total power of 2600kW, the engine displacement is reduced by 40% and the total power is increased by 3%.

[0138] like Figures 4-7 As shown, some embodiments of the present invention further provide a hybrid mining truck energy coordination control system for implementing the above-described hybrid mining truck energy coordination control method. The energy coordination control system includes a total energy coordination controller A1, a generator set energy coordination controller B1, and a DC-DC energy coordination controller B2.

[0139] The total energy coordination controller A1 includes a mining area cycle operating condition model, a driver intention model, and an energy management model. The mining area cyclic operating condition model is used to obtain the cyclic operating conditions of vehicles in the mining area and to determine the working mode of the vehicles based on the cyclic operating conditions.

[0140] The driver intent model is used to obtain driver intent information, such as... Figure 8 As shown, the driver's intention information includes the travel of the accelerator pedal and the travel of the brake pedal.

[0141] The energy management model is used to calculate the corresponding traction power or braking power based on driver intention information, and to allocate the traction power or braking power based on the current vehicle operating mode; it also determines the corresponding engine power demand, DC-DC converter power demand, and charging / discharging commands.

[0142] The generator set energy coordination controller B1 is used to perform energy coordination control of the generator set based on the engine's power demand.

[0143] The DC-DC energy coordination controller B2 is used to perform energy coordination control of the DC-DC converter based on the power demand and charge / discharge commands of the DC-DC converter.

[0144] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0145] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A method for coordinated energy control of a hybrid mining truck, characterized in that, Includes the following steps: The vehicle's cyclic operating conditions in the mining area are obtained, and the vehicle's working mode is determined based on the cyclic operating conditions; the working mode includes at least a traction mode and a braking mode. Acquire driver intention information, which includes the travel distance of the accelerator pedal and the travel distance of the brake pedal; In the traction mode, the corresponding traction power is calculated based on the throttle pedal travel, and the traction power is allocated based on a predetermined allocation strategy to determine the engine power requirement and the DC-DC converter power requirement, and to generate a charging and discharging command. In the braking mode, the corresponding braking power is calculated based on the travel opening of the brake pedal, and the power requirement of the DC-DC converter is determined based on the braking power, and a charging and discharging command is generated. Energy coordination control of the engine group is performed based on the engine's required power; energy coordination control of the DC-DC converter is performed based on the DC-DC converter's required power and the charge / discharge command.

2. The energy coordination control method for hybrid mining trucks according to claim 1, characterized in that, The method for energy coordination control of the engine set based on the engine's required power specifically includes the following steps: A generator set control model is established based on the vehicle's engine universal characteristic curve and generator speed-voltage curve to adaptively adjust and control the generator set's speed, excitation, voltage, and power. Based on the engine's required power and the engine's optimal fuel economy curve, the generator sets are controlled in a tiered manner to determine the number of generator sets connected and the output power of a single generator set. When the number of generator sets connected is greater than or equal to two, a droop control strategy is introduced to perform power balance control on each connected generator set.

3. The energy coordination control method for hybrid mining trucks according to claim 2, characterized in that, The method for establishing a generator set control model includes the following steps: Obtain the universal characteristic curve of the vehicle's engine, and determine the engine speed-power curve based on the universal characteristic curve; Obtain the generator speed-voltage curve of the vehicle, and perform adaptive excitation adjustment based on the generator speed-voltage curve; An adaptive adjustment system for the generator set is established based on the engine speed-power curve and the generator speed-voltage curve. The adaptive adjustment system is used to adaptively adjust and control the speed, excitation, voltage and power of the generator set.

4. The energy coordination control method for hybrid mining trucks according to claim 2, characterized in that, The method for power balance control of each connected generator set by introducing a droop control strategy includes the following steps: Detect the voltage imbalance difference between each generator set; The result of multiplying the voltage imbalance difference by a predetermined first modulation coefficient is taken as the voltage droop modulation coefficient; The droop modulation coefficient is applied to the given value of the excitation current to achieve closed-loop control of generator power balance.

5. The energy coordination control method for hybrid mining trucks according to claim 1, characterized in that, The method for energy coordination control of the DC-DC converter based on the power demand of the DC-DC converter and the charging and discharging command includes the following steps: The power demand of the DC-DC converter is evenly distributed to each DC-DC converter. In DCDC current mode, the power allocated to each DCDC converter is converted into the target charging and discharging current in conjunction with the charging and discharging command; The power of each DC-DC converter is monitored in real time, and a droop control strategy is introduced to adjust the target current of each DC-DC converter in real time to achieve dynamic balance of power of each DC-DC converter.

6. The energy coordination control method for hybrid mining trucks according to claim 5, characterized in that, The method for energy coordination control of a DC-DC converter based on the power demand of the DC-DC converter and the charge / discharge command includes the following further steps: Based on the charge and discharge commands, the automatic charge and discharge switching control of the DC-DC converter is achieved by controlling the target current to smoothly cross zero. During the switching process, hysteresis is set in the zero-crossing region to eliminate the influence of sampling bias.

7. The energy coordination control method for hybrid mining trucks according to claim 1, characterized in that, The predetermined allocation strategy is an optimal power allocation strategy determined based on operating mode characteristic data and power source characteristic data; the allocation of traction power based on the predetermined allocation strategy further includes the following steps: Extract working mode feature data, which includes traction power demand under each working mode; Extract power source feature data; the power source feature data includes battery feature data and engine feature data; Based on the traction power demand, battery characteristic data, and engine characteristic data under the current operating mode, the battery participation strategy is adjusted to achieve optimal power allocation for the traction power.

8. The energy coordination control method for hybrid mining trucks according to claim 1, characterized in that, The operating modes further include a vehicle charging mode and an idle / stop mode; the energy coordination control method further includes the following steps: In the vehicle charging mode, when the predetermined charging conditions are met, the generator's required power is updated to the sum of the traction power and the DC-DC converter's required power.

9. The energy coordination control method for hybrid mining trucks according to claim 1, characterized in that, The operating mode further includes an idle / stop mode; the energy coordination control method further includes the following steps: In the idle / stop mode, the power demand of the engine is made equal to the power demand of the DC-DC converter.

10. The hybrid mining truck energy coordination control system according to claim 1, used to implement the hybrid mining truck energy coordination control method according to any one of claims 1-9, characterized in that, This includes the total energy coordination controller, generator set energy coordination controller, and DC-DC energy coordination controller; The total energy coordination controller includes a mining area cycle operating condition model, a driver intention model, and an energy management model; The mining area cyclic operating condition model is used to obtain the cyclic operating conditions of vehicles in the mining area, and to determine the working mode of vehicles based on the cyclic operating conditions. The driver intention model is used to obtain driver intention information, which includes the travel distance of the accelerator pedal and the travel distance of the brake pedal. The energy management model is used to calculate the corresponding traction power or braking power based on the driver's intention information, and to allocate the traction power or braking power based on the current vehicle's operating mode; and to determine the corresponding engine power demand, DC-DC converter power demand, and charging / discharging commands; The generator set energy coordination controller is used to perform energy coordination control of the generator set based on the engine's required power. The DC-DC energy coordination controller is used to perform energy coordination control on the DC-DC converter based on the power demand of the DC-DC converter and the charge / discharge command.

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