Hybrid power control method, system and crane

Abstract

The present invention relates to a hybrid power control method, system and crane, wherein the control method includes: reading the operation handle opening signal, calculating the oil pump displacement required for the operation; reading the oil pump outlet pressure sensor information, obtaining the hydraulic system pressure, and calculating the torque required for the crane operation through the oil pump displacement; reading the throttle opening signal, calculating the speed required for the operation, and obtaining the target speed of the engine and motor; reading the power battery power, charging and discharging operating power information, and outputting the power battery charging and discharging power demand according to the vehicle electrical balance requirement; combining the above information to calculate the optimal torque actually emitted by the engine, and adjusting the engine to work in the optimal economic range. The hybrid power control method, system and crane of the present invention can effectively improve the operating stability and economy of the hybrid power system. Products that balance stability, economy and environmental protection requirements can be created for crane users.

Description

Technical Field

[0001] The present invention belongs to the technical field of hybrid power control, and in particular relates to a hybrid power control method, system and crane. Background Art

[0002] Cranes are widely used in factories, mines, ports, hydropower stations, buildings, bridges and other fields. Traditional wheeled cranes generally use diesel engines as power sources. Their applications are mature, but they also have the disadvantages of serious pollution and substandard emissions. As the country proposes the goals of carbon peak and carbon neutrality, higher requirements are also put forward for carbon emissions in the crane industry. Energy conservation and environmental protection have become one of the main directions of development of the current crane industry. In recent years, many types of hybrid cranes have appeared on the market, but they are mainly driven by engines and motors alone, and rarely by hybrid drives. The torque and speed required by cranes vary greatly during operation. In order to make the engine work in the best economic range, the motor needs to adjust its output torque from time to time according to the engine output torque and speed. Due to the slow response speed of the engine and large load changes, the motor output torque fluctuates greatly, which can easily cause the crane hoisting to shake. Therefore, when the crane is hybrid, the motor is usually in power generation mode, and it is difficult to adjust the engine output torque under all working conditions. Existing hybrid control methods are mostly for commercial vehicles. The driving resistance of commercial vehicles is related to the slope, wind resistance and rolling resistance. The resistance usually does not change suddenly. When the motor adjusts the engine output torque according to the required torque of the whole machine, the torque will not fluctuate greatly, and the vehicle travels relatively smoothly. However, when the crane is operating, the required torque is related to the lifting weight and the handle opening, and the required torque fluctuates greatly. The traditional hybrid control method cannot meet the hybrid control requirements in the operating conditions of the crane, thereby affecting the normal operation of the crane and the service life of the battery pack. Therefore, how to provide a hybrid control method suitable for the operating conditions of the crane is a technical problem that needs to be solved in this field. Summary of the invention

[0003] Purpose of the invention: In view of the deficiencies of the prior art, the purpose of the present invention is to provide a hybrid power control method, system and crane, so as to improve the operating stability and economy of the hybrid power system.

[0004] Technical solution: The hybrid power control method of the present invention comprises the following steps:

[0005] (1) The vehicle body controller reads the operating handle opening signal, calculates the oil pump displacement required for the operation, and sends a control signal to the oil pump, which operates according to the corresponding displacement;

[0006] (2) The body controller reads the oil pump outlet pressure sensor information to obtain the hydraulic system pressure, and calculates the torque required for crane operation through the oil pump displacement;

[0007] (3) The throttle opening signal is read through the vehicle body controller, the speed required for the operation is calculated, and the target speed of the engine and the motor is obtained; and the motor output target speed is controlled through the motor controller;

[0008] (4) The body controller reads the power battery power, charging and discharging operating power information, and outputs the power battery charging and discharging power requirements based on the vehicle's electrical balance requirements.

[0009] (5) The torque required for crane operation, the target speed of the engine and motor, and the required power for charging and discharging the power battery are comprehensively considered to calculate the optimal torque actually emitted by the engine and adjust the engine to operate in the optimal economic range.

[0010] Furthermore, the oil pump, the engine and the motor are mechanically coupled, and the engine and the oil pump follow the motor to maintain the same speed or a specific ratio of speed.

[0011] Furthermore, when the torque output by the engine is greater than the operating requirements, the motor outputs negative torque to charge the power battery;.

[0012] Furthermore, when the torque output by the engine is less than the operating requirement, the motor outputs positive torque and the power battery discharges.

[0013] Furthermore, the motor is speed-controlled. After the engine emits the corresponding torque, if the torque is insufficient, the motor speed will tend to slow down. In order to keep its operating speed in line with the target speed, the motor will adaptively emit positive torque; if the torque exceeds the operating requirements, the motor speed will tend to accelerate. In order to keep its operating speed in line with the target speed, the motor will adaptively emit negative torque. During the whole process, the motor torque is adaptively adjusted.

[0014] Furthermore, the engine torque is adjusted only when the engine operating speed is consistent with the target speed. During the speed change process, the motor speed changes according to the target speed, the engine torque maintains the original output torque unchanged, and the torque change caused by load fluctuation is adaptively supplemented by the motor.

[0015] The present invention also discloses a hybrid power control system for realizing the above-mentioned hybrid power control method. The hybrid power control system includes: an engine, an engine controller, a motor, a motor controller, a body controller, a pressure sensor, an operating handle, a throttle and an oil pump. The engine, the motor and the oil pump are mechanically coupled and connected, and can be hybrid-driven to drive the oil pump to operate; the body controller is connected to the engine controller, the motor controller, the pressure sensor, the operating handle, the throttle and the power battery by electrical signals.

[0016] The present invention also discloses a crane adopting the hybrid power control system. Furthermore, the crane is a wheeled crane.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following advantages: (1) The engine adopts torque control and the motor adopts speed control, which fully utilizes the fast response speed of the motor to withstand the torque fluctuation and change of the oil pump during crane hoisting, improves the stability of the hybrid power system, and avoids the crane hoisting vibration; (2) The torque and speed required for crane operation are obtained through information such as handle opening, throttle opening, system pressure, etc., and then the optimal output torque of the engine is comprehensively obtained according to the current battery power, so that the engine and motor work at the optimal economic point, thereby improving the overall energy utilization efficiency of the hybrid system and reducing the fuel consumption of the crane operation; (3) The engine output torque changes only when the actual engine speed is consistent with the target speed, which reduces the torque fluctuation of the engine during the hoisting process and reduces the engine fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A control framework diagram of the combined power system provided by the present invention;

[0019] Figure 2 A schematic diagram of the hybrid power control system provided by the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0021] like Figure 1-2 As shown, a hybrid power control system of the present invention includes an engine, an engine controller, a motor, a motor controller, a body controller, a pressure sensor, an operating handle, a throttle and an oil pump. The engine, the motor and the oil pump are mechanically coupled and connected, and the two can drive the oil pump to operate in a mixed manner, and the speeds of the engine, the motor and the oil pump are always the same or in a certain proportion. The body controller is connected to the engine controller, the motor controller, the pressure sensor, the operating handle, the throttle and the power battery by electrical signals. The body controller reads signals such as the pressure sensor pressure signal, the operating handle opening signal, the throttle opening signal, the engine speed signal, the engine torque signal, the motor speed signal, the motor torque signal, etc., and respectively controls the engine output torque and speed, the motor output torque and speed and the operating displacement of the oil pump. The body controller reads the power battery power, charging and discharging operating power information, and is used to control the battery charging and discharging. The engine controller is responsible for reading the engine status information and controlling the engine, and the motor controller is responsible for reading the motor status information and controlling the motor.

[0022] During hybrid operation, the engine uses torque control and the motor uses speed control. The specific control process is as follows:

[0023] The body controller reads the handle opening signal, calculates the oil pump displacement required for the crane operation, and sends a control signal to the oil pump, which runs according to the corresponding displacement; the body controller reads the oil pump outlet pressure sensor information, obtains the hydraulic system pressure, and calculates the torque required for the crane operation through the oil pump displacement. The body controller reads the throttle opening signal, calculates the speed required for the operation, obtains the target speed of the engine and motor, and controls the motor output target speed through the motor controller. Due to the mechanical coupling of the oil pump, engine and motor, the engine and oil pump follow the motor to run at a certain speed.

[0024] The body controller reads the current power of the power battery and the allowable power of charging and discharging, and outputs the power demand of the power battery charging and discharging according to the electrical balance requirements of the vehicle. The optimal torque actually emitted by the engine is calculated by integrating the torque required by the crane operation, the power required for battery charging and discharging, and the target speed of the engine, so that the engine works in the optimal economic range. When the torque emitted by the engine is greater than the operation requirement, the motor emits negative torque to charge the power battery; when the torque emitted by the engine is less than the operation requirement, the motor emits positive torque to discharge the power battery. Since the motor is speed-controlled, after the engine emits the corresponding torque, if the torque is insufficient, the motor speed will tend to slow down. In order to keep its operating speed in line with the target speed, the motor will adaptively emit positive torque; if the torque exceeds the operation requirement, the motor speed will tend to accelerate. In order to keep its operating speed in line with the target speed, the motor will adaptively emit negative torque. During the whole process, the motor torque is adaptively adjusted.

[0025] To avoid excessive fluctuations in engine torque and solve problems such as slow engine response, the engine torque is only adjusted when the engine operating speed is consistent with the target speed (within a certain threshold range). During the speed change, the motor speed changes according to the target speed, and the engine torque maintains the original output torque unchanged. The torque change caused by load fluctuations is adaptively supplemented by the motor.

[0026] The hybrid power control method, system and crane of the present invention calculate the torque and speed required for crane operation by constantly reading the information such as the crane vehicle throttle, oil pump displacement and system pressure, and the engine outputs the best economic torque according to the current speed; the motor speed control constantly responds to the vehicle speed demand, and uses the motor's rapid response characteristics to output torque to adapt to the operation demand, thereby improving the operation stability and economy of the hybrid power system. Products that balance stability, economy and environmental protection requirements can be created for crane users.

Claims

1. A hybrid power control method, It is characterized in that The following steps are involved: (1) The vehicle body controller reads the operating handle opening signal, calculates the oil pump displacement required for the operation, and sends a control signal to the oil pump, which operates according to the corresponding displacement; (2) The body controller reads the oil pump outlet pressure sensor information to obtain the hydraulic system pressure, and calculates the torque required for crane operation through the oil pump displacement; (3) The throttle opening signal is read through the body controller, the speed required for the operation is calculated, and the target speed of the engine and motor is obtained; And control the motor output target speed through the motor controller; (4) The body controller reads the power battery power, charging and discharging operating power information, and outputs the power battery charging and discharging power requirements based on the vehicle's electrical balance requirements; (5) Comprehensively consider the torque required for crane operation, the target speed of the engine and motor, and the required power for charging and discharging the power battery, calculate the optimal torque actually generated by the engine, and adjust the engine to operate in the optimal economic range; The engine torque is adjusted only when the engine operating speed is consistent with the target speed. During the speed change, the motor speed changes according to the target speed, the engine torque maintains the original output torque unchanged, and the torque change caused by load fluctuation is adaptively supplemented by the motor.

2. The hybrid power control method according to claim 1, It is characterized in that The oil pump, the engine and the motor are mechanically coupled, and the engine and the oil pump follow the motor to maintain the same speed or a specific ratio of speed.

3. The hybrid power control method according to claim 1, It is characterized in that When the torque output by the engine is greater than the operating requirements, the motor outputs negative torque to charge the power battery.

4. The hybrid power control method according to claim 1, It is characterized in that When the torque output by the engine is less than the operating requirements, the motor outputs positive torque and the power battery discharges.

5. The hybrid power control method according to claim 1, It is characterized in that The motor is speed controlled and the motor torque is adaptively adjusted.

6. A hybrid power control system, It is characterized in that Used to implement the hybrid power control method as described in any one of claims 1-5.

7. The hybrid power control system according to claim 6, It is characterized in that include: The engine, engine controller, motor, motor controller, body controller, pressure sensor, operating handle, throttle and oil pump are mechanically coupled to the engine, motor and oil pump to drive the oil pump to operate; the body controller is connected to the engine controller, motor controller, pressure sensor, operating handle, throttle and power battery by electrical signals.

8. A crane, It is characterized in that Includes the hybrid power control system as described in claim 6 or 7.

9. The crane according to claim 8, It is characterized in that The crane is a wheeled crane.

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