Hydrogen-electricity series-parallel power device, stacking machine and stacking machine control system

Abstract

The invention relates to the technical field of engineering machinery, in particular to a hydrogen-electricity series-parallel power device, a stacking machine and a stacking machine control system. The hydrogen-electricity series-parallel power device comprises a lithium battery, a hydrogen fuel cell, a DC / DC converter and a power high-voltage box; the lithium battery is electrically connected with the power high-voltage box, and the hydrogen fuel cell is electrically connected with the power high-voltage box through the DC / DC converter; the power high-voltage box is used for acquiring the current SOC of the lithium battery in real time and adjusting the discharge power of the hydrogen fuel battery and the charge-discharge power of the lithium battery in real time based on a preset charge-discharge strategy and a preset overall average power of the stacking machine; the charging and discharging strategy is a strategy for adjusting the discharging power of the hydrogen fuel cell and the charging and discharging power of the lithium battery in real time based on the current SOC of the lithium battery and a preset electric quantity threshold value. The invention has the beneficial effects that when the stacking machine is used in the port loading and unloading operation, the requirement on the equipment energy cruising ability is met, the energy is saved, the environment is protected, and the service life of the battery is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a hydrogen-electric hybrid power device, a forklift and a forklift control system. Background Art

[0002] Empty container stackers are the mainstream equipment for container stacking and transshipment. They can stack up to 8-9 layers of containers and have the characteristics of high site utilization and high speed. Compared with pushing, pulling and lifting completely by manpower, the handling efficiency is higher. Therefore, the industry's demand for fully automatic stackers has increased comprehensively. At this stage, stackers generally use power batteries as a power source. Therefore, the performance of power batteries affects the use of stackers. As a storage structure for power energy, power batteries need to be continuously charged and discharged. High-frequency charging and discharging can easily shorten the service life of power batteries.

[0003] At present, the commonly used power batteries for forklifts include lithium batteries or fuel cells. As the environmental situation becomes increasingly severe, there are higher requirements for energy conservation and emission reduction of agricultural machinery. Forklifts powered by fuel are noisy when working and easily emit pollutants exceeding the standard, which cannot meet the requirements of environmental protection. Although lithium battery forklifts are energy-saving and environmentally friendly, they have a long charging time and short battery life, which cannot meet the requirements for equipment energy endurance in port loading and unloading operations.

[0004] There is an urgent need for a power device that can meet the equipment endurance requirements of forklifts for port operations, ensure the service life of the power battery, and reduce vehicle noise and pollutant emissions during operation. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a hydrogen-electric hybrid power device, a forklift and a forklift control system, which solve the technical problem that when the power battery is used as the power source, frequent charging and discharging leads to a shortened service life of the power battery, as well as the technical problem that when the forklift uses a fuel power source, the noise is loud and the pollutant emissions are large during operation, and the technical problem that when the forklift uses a lithium battery as the power source, the charging time is long and the endurance time is short.

[0007] (II) Technical solution

[0008] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0009] In a first aspect, an embodiment of the present invention provides a hydrogen-electric hybrid power device, which is arranged on a stacker and used to provide a power source for the stacker, and includes a lithium battery, a hydrogen fuel cell, a DC / DC converter and a power high-voltage box;

[0010] The lithium battery is electrically connected to the power high-voltage box, and the hydrogen fuel cell is electrically connected to the power high-voltage box through a DC / DC converter;

[0011] The power high-voltage box is used to obtain the current SOC of the lithium battery in real time, and adjust the discharge power of the hydrogen fuel cell and the charge and discharge power of the lithium battery in real time based on the preset charge and discharge strategy and the preset average power of the entire stacker;

[0012] The charging and discharging strategy is: based on the current SOC of the lithium battery and a preset power threshold, a strategy for adjusting the discharge power of the hydrogen fuel cell and the charging and discharging power of the lithium battery in real time; the power threshold is a preset lithium battery power threshold.

[0013] Optionally, the power threshold includes a first power threshold and a second power threshold, and the first power threshold is greater than the second power threshold;

[0014] Then, the power high-voltage box obtains the current SOC of the lithium battery in real time, and adjusts the discharge power of the hydrogen fuel cell and the charge and discharge power of the lithium battery in real time based on the preset charge and discharge strategy and the preset average power of the stacker, including:

[0015] When the current SOC of the lithium battery obtained in real time is greater than the first power threshold, the discharge power of the lithium battery is adjusted to the average power of the whole machine, and the hydrogen fuel cell is adjusted not to discharge;

[0016] When the current SOC of the lithium battery obtained in real time is less than the first power threshold and greater than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the first discharge power, and the discharge power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the discharge powers of the hydrogen fuel cell and the lithium battery is equal to the average power of the whole machine;

[0017] When the current SOC of the lithium battery acquired in real time is less than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the second discharge power, and the charging power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the charging power of the lithium battery and the average power of the whole machine is equal to the second discharge power of the hydrogen fuel cell;

[0018] The first discharge power and the second discharge power are both discharge powers preset by the hydrogen fuel cell, and the first discharge power is less than the average power of the whole machine and less than the second discharge power.

[0019] In a second aspect, an embodiment of the present invention provides a hydrogen-electric hybrid stacker control system, comprising an execution module, a control module and a power module, wherein the power module is the hydrogen-electric hybrid power device as described in claim 1 or 2; the execution module comprises: a lifting mechanism, a traveling mechanism and an auxiliary mechanism;

[0020] The lifting mechanism is connected to the control module and the power module respectively;

[0021] The traveling mechanism is connected to the control module and the power module respectively;

[0022] The auxiliary mechanism is connected to the control module and the power module respectively;

[0023] The power module is used to provide power to the control module and the execution module.

[0024] Optionally, the lifting mechanism includes a lifting motor controller, a lifting motor, a lifting pump and a lifting cylinder; the lifting motor is electrically connected to the lifting motor controller and is transmission-connected to the lifting pump, and the lifting pump is connected to the lifting cylinder; the lifting motor controller is respectively connected to the power module and the control module; the lifting motor is a permanent magnet synchronous motor;

[0025] The lifting motor controller is used to drive the lifting motor output shaft to rotate forward when receiving a heavy object lifting instruction sent by the control module, thereby driving the lifting pump to produce hydraulic oil to push the lifting cylinder to extend or maintain;

[0026] When the control module receives a command to lower the heavy object, it stops driving the lifting motor, causing the hydraulic oil generated in the lifting cylinder due to the load reduction to drive the lifting pump to reverse, thereby driving the lifting motor to reverse and generate electricity to recover potential energy.

[0027] Optionally, the travel mechanism includes a travel motor controller and a travel motor, and a rotary transformer; the travel motor controller is electrically connected to the travel motor; the travel motor controller is respectively connected to the power module and the execution module;

[0028] The rotary transformer is arranged on the output shaft of the traveling motor, and is used to detect the speed of the traveling motor at the output end of the traveling motor in real time, and send it to the traveling motor controller;

[0029] The travel motor controller is used to, when receiving a movement instruction sent by the control module, drive the output shaft of the travel motor to rotate forward based on the movement instruction, thereby driving the whole machine to travel; and during the driving of the whole machine, obtain the travel motor speed in real time through the rotary transformer, and generate a speed adjustment instruction based on the travel motor speed and the target speed corresponding to the received movement instruction and send it to the travel motor;

[0030] The movement instruction includes a torque signal for driving the whole machine to move;

[0031] The speed adjustment instruction is an instruction for controlling the travel motor to adjust the speed of its output shaft.

[0032] Optionally, the travel mechanism further comprises a travel component; the travel component is transmission-connected to the travel motor; the travel motor is a permanent magnet synchronous motor;

[0033] When the output shaft of the travel motor is not driven by the travel motor controller and the stacker keeps moving due to inertia, the travel component is used to drive the travel motor to reverse and generate electricity to recover kinetic energy.

[0034] Optionally, the auxiliary mechanism includes an auxiliary motor controller, an auxiliary motor, an auxiliary motor coupling, an auxiliary hydraulic pump, a brake gear pump, a brake valve and a hydraulic steering gear;

[0035] The auxiliary hydraulic pump is of through-shaft type;

[0036] The auxiliary motor controller is electrically connected to the auxiliary motor, the output end of the auxiliary motor is transmission-connected to the input end of the auxiliary hydraulic pump through the auxiliary motor coupling, the auxiliary hydraulic pump is transmission-connected to the brake gear pump through the auxiliary hydraulic pump tail stop; the auxiliary hydraulic pump is communicated with the hydraulic steering gear; the brake gear pump is communicated with the brake valve;

[0037] The auxiliary motor controller is connected to the control module and the power module respectively;

[0038] The auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a first speed in real time, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can steer and brake at any time;

[0039] The hydraulic steering gear is used to drive the stacker to steer;

[0040] The brake valve is used to drive the stacker to brake.

[0041] Optionally, the auxiliary mechanism further includes a multi-way proportional valve and a converging one-way valve;

[0042] The lifting mechanism includes a lifting motor controller, a lifting motor, a lifting pump and a lifting cylinder;

[0043] The lifting motor is electrically connected to the lifting motor controller and is also transmission-connected to the lifting pump, which is connected to the lifting oil cylinder; the lifting motor controller is respectively connected to the power module and the control module;

[0044] The auxiliary hydraulic pump is connected to the lifting cylinder through the multi-way proportional valve and the converging check valve in sequence;

[0045] The lifting motor is used to drive the output shaft of the lifting motor to rotate forward when receiving a heavy object lifting instruction sent by the control module, thereby driving the lifting pump to produce hydraulic oil to supply oil for the lifting action of the lifting cylinder;

[0046] The auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a second speed when receiving a heavy object lifting instruction sent by the control module, so that part of the hydraulic oil generated by the auxiliary hydraulic pump passes through the multi-way proportional valve and the converging check valve, and then merges with the hydraulic oil generated by the lifting hydraulic pump to supply oil for the lifting action of the lifting cylinder;

[0047] The second rotation speed is greater than the first rotation speed.

[0048] Optionally, the auxiliary mechanism further includes a steering priority valve, a multi-way proportional valve and a swing cylinder;

[0049] The auxiliary hydraulic pump is connected to the hydraulic steering gear through the steering priority valve, and the auxiliary hydraulic pump is connected to the swing cylinder and the lifting cylinder respectively through the multi-way proportional valve;

[0050] Then, the auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a first speed in real time, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear through the steering priority valve, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can steer and brake at any time;

[0051] Moreover, when receiving a heavy object lifting instruction or a swing instruction sent by the control module, the output shaft of the auxiliary motor is driven to rotate at a second speed, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear through the steering priority valve and to the swing cylinder / lifting cylinder through the multi-way proportional valve, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can turn and brake at any time when swinging / lifting;

[0052] The second rotation speed is greater than the first rotation speed.

[0053] In a third aspect, an embodiment of the present invention provides a hydrogen-electric hybrid stacker, including a control system and an action system, characterized in that the control system is the above-mentioned hydrogen-electric hybrid stacker control system.

[0054] (III) Beneficial effects

[0055] The beneficial effects of the present invention are as follows: a hydrogen-electric hybrid power device of the present invention adopts hydrogen-electric hybrid as a power source and adds a lithium battery management strategy, namely a charging and discharging strategy. Compared with the prior art, it can extend the service life of the lithium battery while meeting the requirements for equipment endurance when the forklift is operating in the port, and reduces vehicle noise and pollutant emissions during the operation of the forklift. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 This is a schematic diagram of the structure of a hydrogen-electric hybrid power device;

[0057] Figure 2The figure is a schematic diagram of the control system structure of a hydrogen-electric hybrid stacker. DETAILED DESCRIPTION

[0058] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0059] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0060] Example 1

[0061] This embodiment provides a hydrogen-electric hybrid power device, such as Figure 1 As shown, it includes: lithium battery, hydrogen fuel cell, DC / DC converter and power high voltage box;

[0062] The lithium battery is electrically connected to the power high-voltage box, and the hydrogen fuel cell is electrically connected to the power high-voltage box through a DC / DC converter;

[0063] The power high-voltage box is used to obtain the current SOC (SOC is the remaining capacity of the battery) of the lithium battery in real time, and adjust the discharge power of the hydrogen fuel cell and the charge and discharge power of the lithium battery in real time based on the preset charge and discharge strategy and the preset average power of the stacker;

[0064] The charging and discharging strategy is: when the current SOC of the lithium battery obtained in real time is greater than the first power threshold, the discharge power of the lithium battery is adjusted to the average power of the whole machine to adjust the hydrogen fuel cell not to discharge;

[0065] When the current SOC of the lithium battery obtained in real time is less than the first power threshold and greater than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the first discharge power, and the discharge power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the discharge powers of the hydrogen fuel cell and the lithium battery is equal to the average power of the whole machine;

[0066] When the current SOC of the lithium battery acquired in real time is less than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the second discharge power, and the charging power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the charging power of the lithium battery and the average power of the whole machine is equal to the second discharge power of the hydrogen fuel cell;

[0067] The first discharge power and the second discharge power are both discharge powers pre-set for the hydrogen fuel cell, and the first discharge power < the average power of the whole machine < the second discharge power. The power threshold includes a first power threshold and a second power threshold, and the first power threshold is greater than the second power threshold.

[0068] The present embodiment provides a hydrogen-electric hybrid power device, which adopts hydrogen-electric hybrid as a power source and adds a lithium battery management strategy, namely a charging and discharging strategy. It extends the service life of the lithium battery while meeting the requirements for the endurance of the equipment when the forklift is operating in the port, and reduces the vehicle noise and pollutant emissions during the operation of the forklift.

[0069] Example 2

[0070] This embodiment provides a hydrogen-electric hybrid stacker control system, such as Figure 2 As shown, it includes an execution module, a control module and a power module, the power module is the hydrogen-electric hybrid power device described in Example 1; the execution module includes: a lifting mechanism, a traveling mechanism and an auxiliary mechanism;

[0071] The lifting mechanism is connected to the control module and the power module respectively;

[0072] The traveling mechanism is connected to the control module and the power module respectively;

[0073] The auxiliary mechanism is connected to the control module and the power module respectively;

[0074] The power module is used to provide power to the control module and the execution module.

[0075] The lifting mechanism comprises: a lifting motor controller, a lifting motor, a lifting pump and a lifting oil cylinder; the lifting motor is electrically connected to the lifting motor controller and is transmission-connected to the lifting pump, and the lifting pump is connected to the lifting oil cylinder; the lifting motor controller is respectively connected to the power high-voltage box and the control module; the lifting motor is a permanent magnet synchronous motor;

[0076] The lifting motor controller is used to drive the lifting motor output shaft to rotate forward when receiving a heavy object lifting instruction sent by the control module, thereby driving the lifting pump to produce hydraulic oil to push the lifting cylinder to extend or maintain;

[0077] When the control module receives a command to lower the heavy object, it stops driving the lifting motor, causing the hydraulic oil generated in the lifting cylinder due to the load reduction to drive the lifting pump to reverse, thereby driving the lifting motor to reverse and generate electricity to recover potential energy.

[0078] The travel mechanism includes a travel motor controller, a travel motor, and a rotary transformer; the travel motor controller is electrically connected to the travel motor; the travel motor controller is respectively connected to the power module and the control module;

[0079] The rotary transformer is arranged on the output shaft of the traveling motor, and is used to detect the speed of the traveling motor at the output end of the traveling motor in real time, and send it to the traveling motor controller;

[0080] The travel motor controller is used to, when receiving a movement instruction sent by the control module, drive the output shaft of the travel motor to rotate forward based on the movement instruction, thereby driving the whole machine to travel; and during the driving of the whole machine, obtain the travel motor speed in real time through the rotary transformer, and generate a speed adjustment instruction based on the travel motor speed and the target speed corresponding to the received movement instruction and send it to the travel motor;

[0081] The movement instruction includes a torque signal for driving the whole machine to move;

[0082] The speed adjustment instruction is an instruction for controlling the travel motor to adjust the speed of its output shaft.

[0083] The travel mechanism further comprises a travel component; the travel component is transmission-connected to the travel motor; the travel motor is a permanent magnet synchronous motor;

[0084] When the output shaft of the travel motor is not driven by the travel motor controller and the stacker keeps moving due to inertia, the travel component is used to drive the travel motor to reverse and generate electricity to recover kinetic energy.

[0085] The auxiliary mechanism includes an auxiliary motor controller, an auxiliary motor, an auxiliary motor coupling, an auxiliary hydraulic pump, a brake gear pump, a brake valve, a hydraulic steering gear, a multi-way proportional valve, a confluence check valve, a steering priority valve and a swing cylinder;

[0086] The auxiliary hydraulic pump is a through-shaft type.

[0087] The auxiliary motor controller is electrically connected to the auxiliary motor, the output end of the auxiliary motor is transmission-connected to the input end of the auxiliary hydraulic pump through the auxiliary motor coupling, and the auxiliary hydraulic pump is transmission-connected to the brake gear pump through the auxiliary hydraulic pump tail stop;

[0088] The auxiliary hydraulic pump is connected to the hydraulic steering gear through the steering priority valve, and is connected to the lifting cylinder and the swing cylinder through the multi-way proportional valve, and a confluence check valve is provided between the multi-way proportional valve and the lifting cylinder;

[0089] The auxiliary motor controller is connected to the control module and the power module respectively;

[0090] The auxiliary motor controller drives the output shaft of the auxiliary motor to rotate at a first speed in real time, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear through the steering priority valve, and drives the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can steer and brake at any time;

[0091] The auxiliary motor controller is also used to drive the output shaft of the auxiliary motor to rotate at a second speed when receiving a heavy object lifting command or a swing command sent by the control module, thereby driving the hydraulic oil generated by the auxiliary hydraulic pump to supply oil to the hydraulic steering gear through the steering priority valve and to the swing cylinder / lifting cylinder through the multi-way proportional valve, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the forklift can turn and brake at any time when swinging / lifting; the second speed is greater than the first speed.

[0092] A hydrogen-electric hybrid forklift control system provided in this embodiment meets the requirements for equipment endurance when the forklift is operating in a port, reduces vehicle noise and pollutant emissions during the operation of the forklift, and provides an energy recovery method, thereby reducing energy consumption during the operation of the forklift and reducing operating costs.

[0093] Example 3

[0094] This embodiment provides a hydrogen-electric hybrid stacker control system, including: a power module, an execution module and a control module;

[0095] The power module includes: lithium battery, hydrogen fuel cell, DC / DC converter and power high-voltage box; hydrogen fuel cell mainly realizes the conversion of hydrogen energy into electrical energy to provide electrical energy for the whole power module. The lithium battery is connected to the power high-voltage box, the hydrogen fuel cell is connected to the power high-voltage box through the DC / DC converter, and the power high-voltage box is connected to the control module and the execution module respectively.

[0096] Hydrogen fuel cells have an internal protection mechanism. When hydrogen leakage, insufficient hydrogen pressure, module temperature is too high, or the cooling and filtering device is not started, the hydrogen fuel cell enters a self-protection mechanism and is not allowed to operate.

[0097] In general, the power module also includes a hydrogen supply device and a cooling and filtering device. The hydrogen supply device includes a hydrogen bottle, a pressure reducing valve, a stop valve and a hydrogen leakage sensor; the hydrogen bottle is connected to the hydrogen filling port of the hydrogen fuel cell through the pressure reducing valve, and the stop valve is arranged on the pipeline between the hydrogen bottle and the hydrogen filling port; the hydrogen leakage sensor is arranged on the hydrogen bottle for real-time detection of whether the hydrogen is leaking; and the control module is connected with the hydrogen leakage sensor and the stop valve to determine whether a leak occurs based on the detection data of the hydrogen leakage sensor, and when a leak occurs, a stop valve closing instruction is sent to control the stop valve to close. The above structure realizes the reduction of the hydrogen pressure in the hydrogen bottle to the gas pressure that the hydrogen fuel cell can withstand through the pressure reducing valve, and supplies hydrogen to the hydrogen fuel cell; each hydrogen bottle port is equipped with a stop valve, and the stop valve is closed in the event of hydrogen leakage or abnormal operation of the module.

[0098] The cooling filter device is used to release the heat of the hydrogen fuel cell to ensure that the module operating temperature is within the allowable range. Since the coolant must flow through the electrode plate of the hydrogen fuel cell, the filter system must not only filter out impurities in the coolant, but also filter out ions in the coolant to ensure that there is no leakage and burn the module electrode plate.

[0099] During the design, the selection of hydrogen fuel cells is matched according to the average power of the stacker. The maximum output power of the lithium battery must meet the transient maximum power requirements of the stacker, ensuring that the power module meets the average power output and transient power requirements of the whole machine. In order to ensure the safety of the power module, the connection line between the DC / DC converter and the power high-voltage box is equipped with a hydrogen fuel cell circuit breaker and a fuse. Before the hydrogen fuel cell is operated, the hydrogen fuel cell circuit breaker and the fuse are in the disconnected state. The DC / DC converter is used to increase the output voltage of the hydrogen fuel cell to the bus voltage to ensure that the energy of the hydrogen fuel cell is in the output state. The DC / DC converter has a buffer circuit inside to prevent the contactor from burning the contactor contacts due to the instantaneous voltage difference. The working principle of the buffer circuit is to balance the voltage difference between the two ends of the circuit with a small current by pulling in the resistor side contactor, so that the voltage at both ends is equal, and then the large contactor is pulled in, and the two ends of the circuit enter the normal working state.

[0100] The hydrogen fuel cell has two net output power values, namely the maximum net power value (i.e., the second discharge power) and the high-efficiency net power value (i.e., the first discharge power). When the high-efficiency net power value is statically output, the hydrogen consumption per unit output power is the lowest, among which the maximum net power output value is higher than the system average power, and the high-efficiency net power value is slightly lower than the system average power. When the lithium battery is charged and discharged, the SOC (remaining capacity of the battery) works between the high-capacity SOCH (first power threshold) and the low-capacity SOCL (second power threshold). The lithium battery working between SOCH and SOCL is conducive to extending the service life, and the charging and discharging current meets the maximum discharge demand of the stacker. The specific strategy is as follows: When the current SOC of the lithium battery is lower than SOCH, the hydrogen fuel cell starts and outputs according to the high-efficiency net power value. Since the high-efficiency net power value is slightly lower than the system average power, the insufficient power is supplemented by the lithium battery, so the current SOC of the battery will gradually decrease. When the current SOC of the lithium battery is lower than SOCH, the hydrogen fuel cell outputs according to the maximum net power. Since the maximum net power is higher than the system average power, the SOC will increase rapidly. When the SOC is higher than the high-capacity SOCH value, the hydrogen fuel cell will output at a high-efficiency net power value again and repeat the previous control action. The advantages of this charging and discharging strategy are: first, it allows the hydrogen fuel cell to work in a high-efficiency state for more time, saving hydrogen; second, it allows the lithium battery's SOC to change in the high-life area as much as possible, extending the battery life.

[0101] Typically, the power high-voltage box includes a battery management component BMS and a battery distribution unit PDU. The battery distribution unit PDU divides the high-voltage power supply from the power module into multiple paths, including the main power supply circuit (including the lifting motor controller, lifting motor, driving motor controller, driving motor, auxiliary motor controller and auxiliary motor), two battery charging ports, and one battery cooling high-voltage port.

[0102] The execution module includes a lifting mechanism, a traveling mechanism and an auxiliary mechanism; the lifting mechanism is connected to the control module and the power module respectively; the traveling mechanism is connected to the control module and the power module respectively; and the auxiliary mechanism is connected to the control module and the power module respectively.

[0103] The travel mechanism includes a travel motor buffer circuit, a travel motor controller, a travel motor and a travel component;

[0104] The travel motor controller is electrically connected to the travel motor, the travel motor is transmission-connected to the travel component, the travel motor controller is electrically connected to the power high-voltage box through a DC bus, and the travel motor buffer circuit is arranged on the connection line between the travel motor controller and the DC bus.

[0105] When the stacker is turned on, the contactor on the resistor side of the travel motor buffer circuit is first energized. Because of the existence of the resistor, a small current can be guaranteed to balance the pressure difference of the travel motor buffer circuit. After the voltages at both ends of the travel motor buffer circuit are equal, the main contactor is energized. Directly energizing the main contactor will cause instantaneous overcurrent and burn the contacts. The travel motor controller and the travel motor adopt speed closed-loop control. A rotary transformer is installed on the travel motor. This component converts the motor rotation speed into a voltage signal and feeds it back to the travel motor controller. The travel component includes a universal coupling and a drive axle. The travel motor is rigidly connected to the drive axle flange through a universal coupling. The travel motor adopts a torque control mode instead of a speed control mode. When the whole machine is traveling and the motor stops driving, the whole machine is affected by inertia and needs to maintain the driving state. The travel component drives the travel motor to rotate. The travel motor is in a power generation state. The generated current flows back to the DC bus to recover the kinetic energy generated by inertia to charge the lithium battery or power other mechanisms of the execution module.

[0106] The lifting mechanism includes a lifting motor buffer circuit, a lifting motor controller, a lifting motor, a lifting coupling, a lifting coupling bell, a lifting pump and a lifting cylinder. The lifting motor controller is electrically connected to the lifting motor, the output shaft of the lifting motor is drivingly connected to the lifting pump through the lifting coupling, the lifting coupling bell is arranged on the lifting coupling to protect the lifting coupling, and the lifting pump is connected to the lifting cylinder through a hydraulic pipeline; the lifting motor controller is electrically connected to the power high-voltage box through a DC bus, and the lifting motor buffer circuit is arranged on the connection line between the travel motor controller and the DC bus.

[0107] The function of the lifting motor buffer circuit is the same as that of the driving motor buffer circuit, which prevents the main contactor from being directly attracted and burning the contacts due to instantaneous overcurrent. The lifting motor controller and the lifting motor adopt speed closed-loop control. The lifting motor is also equipped with a rotary transformer, which converts the motor rotation speed into a voltage signal and feeds it back to the lifting motor controller.

[0108] The lifting pump has two working conditions: hydraulic pump and hydraulic motor. When the weight rises, it is the hydraulic pump working condition, and the hydraulic pump pushes the two oil cylinders to lift; when the weight falls, it is the hydraulic motor working condition. The high-pressure oil generated by the weight drives the motor to rotate, driving the lifting motor to reverse and generate electricity, generating current that flows back to the DC bus and recovers the descending potential energy.

[0109] The auxiliary mechanism includes an auxiliary motor controller, an auxiliary motor, an auxiliary motor buffer circuit, an auxiliary motor coupling, an auxiliary motor bell, an auxiliary hydraulic pump, and a brake gear pump. The auxiliary motor controller is electrically connected to the auxiliary motor, and the auxiliary motor controller is electrically connected to the power high-voltage box through a DC bus. An auxiliary motor buffer circuit is provided on the connection line between the auxiliary motor controller and the DC bus. The output shaft of the auxiliary motor is connected to the input shaft of the auxiliary hydraulic pump through an auxiliary motor coupling. The auxiliary hydraulic pump is fixed to the auxiliary motor through the auxiliary motor bell. The auxiliary hydraulic pump is a through-shaft type and is connected to the brake gear pump through the stopper at the rear of the auxiliary hydraulic pump, so that the input shaft of the auxiliary hydraulic pump can directly drive the input shaft of the brake gear pump, and the auxiliary motor can drive the auxiliary hydraulic pump and the brake gear pump at the same time.

[0110] The function of the auxiliary motor buffer circuit is the same as that of the lifting motor buffer circuit and the travel motor buffer circuit, which prevents the main contactor from being directly attracted and burning the contacts due to instantaneous overcurrent. The auxiliary motor controller and the auxiliary motor are speed closed-loop controlled. The auxiliary motor is equipped with a rotary transformer, which can convert the motor rotation speed into a voltage signal and feed it back to the auxiliary motor controller.

[0111] The auxiliary hydraulic pump is a hydraulic steering element, which is connected to the hydraulic steering gear through the steering priority valve. To ensure the safety of the whole machine, the steering priority valve and the hydraulic steering gear need to be in standby state at the same time. The flow rate of hydraulic oil provided by the auxiliary hydraulic pump for steering is slightly higher than the maximum flow rate required for the steering action. The brake gear pump is connected to the brake valve. In order to ensure braking at any time, a brake accumulator is set, and it is ensured that the auxiliary gear pump can fill the brake accumulator at any time. The auxiliary motor needs to always maintain a certain speed. At the same time, the auxiliary hydraulic pump must also merge with the lifting pump to supply oil to the lifting cylinder, and supply oil to the swing cylinder separately. In order to meet the above requirements, the auxiliary motor of the present invention has two speeds. When the hoist has no swinging and lifting movements, the auxiliary motor operates at a first speed that meets the flow rate of steering and braking. When there is lifting and hoisting action, the auxiliary motor operates at a high speed. That is, the auxiliary hydraulic pump is connected to the hydraulic steering gear through the steering priority valve, and is respectively connected to the swing cylinder and the lifting cylinder through the multi-way proportional valve, and a combining check valve is provided on the connecting pipeline between the multi-way proportional valve and the lifting cylinder; the brake gear pump is connected to the brake valve, and the brake valve usually includes a parking brake valve and a service brake valve, and a brake filling valve and an accumulator can usually be provided on the connecting pipeline between the brake gear pump and the brake valve to ensure normal braking in an emergency.

[0112] In this embodiment, the empty container forklift provided utilizes hydraulic pressure and electronic control at the same time to realize the recovery of regenerated energy, and the hydrogen-electric hybrid mode reduces energy consumption, extends the service life of the lithium battery, meets the requirements for equipment endurance when the forklift is operating in the port, and reduces vehicle noise and pollutant emissions during the operation of the forklift.

[0113] Example 4

[0114] A hydrogen-electric hybrid stacker comprises a control system and an action system, wherein the control system is the hydrogen-electric hybrid stacker control system in the above-mentioned embodiment 2 or embodiment 3.

[0115] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0116] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0117] In the present invention, unless otherwise clearly specified and limited, when a first feature is “on” or “below” a second feature, it may be that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, when a first feature is “above”, “above” or “above” a second feature, it may be that the first feature is directly above or obliquely above the second feature, or it may simply mean that the first feature is higher in level than the second feature. When a first feature is “below”, “below” or “below” a second feature, it may be that the first feature is directly below or obliquely below the second feature, or it may simply mean that the first feature is lower in level than the second feature.

[0118] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0119] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A hydrogen-electric hybrid power device, which is arranged on a forklift and used to provide a power source for the forklift, characterized in that: The power device includes a lithium battery, a hydrogen fuel cell, a DC / DC converter and a power high-voltage box; The lithium battery is electrically connected to the power high-voltage box, and the hydrogen fuel cell is electrically connected to the power high-voltage box through a DC / DC converter; The power high-voltage box is used to obtain the current SOC of the lithium battery in real time, and adjust the discharge power of the hydrogen fuel cell and the charge and discharge power of the lithium battery in real time based on the preset charge and discharge strategy and the preset average power of the entire stacker; The charging and discharging strategy is: based on the current SOC of the lithium battery and a preset power threshold, a strategy for adjusting the discharge power of the hydrogen fuel cell and the charging and discharging power of the lithium battery in real time; the power threshold is a preset lithium battery power threshold.

2. The hydrogen-electric hybrid power device according to claim 1, characterized in that: The power threshold includes a first power threshold and a second power threshold, and the first power threshold is greater than the second power threshold; Then, the power high-voltage box obtains the current SOC of the lithium battery in real time, and adjusts the discharge power of the hydrogen fuel cell and the charge and discharge power of the lithium battery in real time based on the preset charge and discharge strategy and the preset average power of the stacker, including: When the current SOC of the lithium battery obtained in real time is greater than the first power threshold, the discharge power of the lithium battery is adjusted to the average power of the whole machine, and the hydrogen fuel cell is adjusted not to discharge; When the current SOC of the lithium battery obtained in real time is less than the first power threshold and greater than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the first discharge power, and the discharge power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the discharge powers of the hydrogen fuel cell and the lithium battery is equal to the average power of the whole machine; When the current SOC of the lithium battery acquired in real time is less than the second power threshold, the hydrogen fuel cell is adjusted to discharge at the second discharge power, and the charging power of the lithium battery is adjusted based on the average power of the whole machine, so that the sum of the charging power of the lithium battery and the average power of the whole machine is equal to the second discharge power of the hydrogen fuel cell; The first discharge power and the second discharge power are both discharge powers preset by the hydrogen fuel cell, and the first discharge power is less than the average power of the whole machine and less than the second discharge power.

3. A hydrogen-electric hybrid stacker control system, characterized in that: It includes an execution module, a control module and a power module, wherein the power module is the hydrogen-electric hybrid power device as described in claim 1 or 2; the execution module includes: a lifting mechanism, a traveling mechanism and an auxiliary mechanism; The lifting mechanism is connected to the control module and the power module respectively; The traveling mechanism is connected to the control module and the power module respectively; The auxiliary mechanism is connected to the control module and the power module respectively; The power module is used to provide power to the control module and the execution module.

4. The hydrogen-electric hybrid stacker control system according to claim 3 is characterized in that: The lifting mechanism includes a lifting motor controller, a lifting motor, a lifting pump and a lifting cylinder; the lifting motor is electrically connected to the lifting motor controller and is transmission-connected to the lifting pump, and the lifting pump is connected to the lifting cylinder; the lifting motor controller is respectively connected to the power module and the control module; the lifting motor is a permanent magnet synchronous motor; The lifting motor controller is used to drive the lifting motor output shaft to rotate forward when receiving a heavy object lifting instruction sent by the control module, thereby driving the lifting pump to produce hydraulic oil to push the lifting cylinder to extend or maintain; When the control module receives a command to lower the heavy object, it stops driving the lifting motor, causing the hydraulic oil generated in the lifting cylinder due to the load reduction to drive the lifting pump to reverse, thereby driving the lifting motor to reverse and generate electricity to recover potential energy.

5. The hydrogen-electric hybrid stacker control system according to claim 3 is characterized in that: The travel mechanism includes a travel motor controller, a travel motor, and a rotary transformer; the travel motor controller is electrically connected to the travel motor; the travel motor controller is respectively connected to the power module and the execution module; The rotary transformer is arranged on the output shaft of the traveling motor, and is used to detect the speed of the traveling motor at the output end of the traveling motor in real time, and send it to the traveling motor controller; The travel motor controller is used to, when receiving a movement instruction sent by the control module, drive the output shaft of the travel motor to rotate forward based on the movement instruction, thereby driving the entire machine to travel; During the driving of the whole machine, the rotation speed of the driving motor is obtained in real time through the rotary transformer, and based on the rotation speed of the driving motor and the target speed corresponding to the received movement instruction, a speed adjustment instruction is generated and sent to the driving motor; The movement instruction includes a torque signal for driving the whole machine to move; The speed adjustment instruction is an instruction for controlling the travel motor to adjust the speed of its output shaft.

6. The hydrogen-electric hybrid stacker control system according to claim 5, characterized in that: The travel mechanism further comprises a travel component; the travel component is transmission-connected to the travel motor; the travel motor is a permanent magnet synchronous motor; When the output shaft of the travel motor is not driven by the travel motor controller and the stacker keeps moving due to inertia, the travel component is used to drive the travel motor to reverse and generate electricity to recover kinetic energy.

7. The hydrogen-electric hybrid stacker control system according to claim 3 is characterized in that: The auxiliary mechanism includes an auxiliary motor controller, an auxiliary motor, an auxiliary motor coupling, an auxiliary hydraulic pump, a brake gear pump, a brake valve and a hydraulic steering gear; The auxiliary hydraulic pump is of through-shaft type; The auxiliary motor controller is electrically connected to the auxiliary motor, the output end of the auxiliary motor is transmission-connected to the input end of the auxiliary hydraulic pump through the auxiliary motor coupling, the auxiliary hydraulic pump is transmission-connected to the brake gear pump through the auxiliary hydraulic pump tail stop; the auxiliary hydraulic pump is communicated with the hydraulic steering gear; the brake gear pump is communicated with the brake valve; The auxiliary motor controller is connected to the control module and the power module respectively; The auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a first speed in real time, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can steer and brake at any time; The hydraulic steering gear is used to drive the stacker to steer; The brake valve is used to drive the stacker to brake.

8. The hydrogen-electric hybrid stacker control system according to claim 7, characterized in that: The auxiliary mechanism also includes a multi-way proportional valve and a converging check valve; The lifting mechanism includes a lifting motor controller, a lifting motor, a lifting pump and a lifting cylinder; The lifting motor is electrically connected to the lifting motor controller and is also transmission-connected to the lifting pump, which is connected to the lifting oil cylinder; the lifting motor controller is respectively connected to the power module and the control module; The auxiliary hydraulic pump is connected to the lifting cylinder through the multi-way proportional valve and the converging check valve in sequence; The lifting motor is used to drive the output shaft of the lifting motor to rotate forward when receiving a heavy object lifting instruction sent by the control module, thereby driving the lifting pump to produce hydraulic oil to supply oil for the lifting action of the lifting cylinder; The auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a second speed when receiving a heavy object lifting instruction sent by the control module, so that part of the hydraulic oil generated by the auxiliary hydraulic pump passes through the multi-way proportional valve and the converging check valve, and then merges with the hydraulic oil generated by the lifting hydraulic pump to supply oil for the lifting action of the lifting cylinder; The second rotation speed is greater than the first rotation speed.

9. The hydrogen-electric hybrid stacker control system according to claim 7, characterized in that: The auxiliary mechanism also includes a steering priority valve, a multi-way proportional valve and a swing cylinder; The auxiliary hydraulic pump is connected to the hydraulic steering gear through the steering priority valve, and the auxiliary hydraulic pump is connected to the swing cylinder and the lifting cylinder respectively through the multi-way proportional valve; Then, the auxiliary motor controller is used to drive the output shaft of the auxiliary motor to rotate at a first speed in real time, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear through the steering priority valve, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can steer and brake at any time; Moreover, when receiving a heavy object lifting instruction or a swing instruction sent by the control module, the output shaft of the auxiliary motor is driven to rotate at a second speed, thereby driving the auxiliary hydraulic pump to generate hydraulic oil to supply oil to the hydraulic steering gear through the steering priority valve and to the swing cylinder / lifting cylinder through the multi-way proportional valve, and driving the brake gear pump to generate hydraulic oil to supply oil to the brake valve, so that the stacker can turn and brake at any time when swinging / lifting; The second rotation speed is greater than the first rotation speed.

10. A hydrogen-electric hybrid stacker, comprising a control system and an action system, characterized in that: The control system is the hydrogen-electric hybrid stacker control system as described in any one of claims 3 to 9.

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