A method and system for dynamic performance matching of pure electric graders

Abstract

The application relates to the field of land levelers, and particularly discloses a dynamic efficiency matching method and system for a pure electric land leveler, which specifically comprises the following steps: acquiring the hydraulic oil pressure in a hydraulic circuit; detecting the operation action of a driver, and calculating the total required hydraulic oil flow according to the operation action of the driver; based on the hydraulic oil pressure in the hydraulic circuit and the total required hydraulic transmission medium flow, finding out the motor rotating speed corresponding to the maximum total efficiency of a working device drive through a cyclic optimization algorithm, and recording the optimal motor rotating speed as the actual execution rotating speed instruction; and delivering the actual execution rotating speed instruction to a working device motor controller. According to the application, the motor parameters of the working device are dynamically adjusted according to the actual working conditions, so that the energy efficiency maximization and performance optimization are realized.

Description

Technical Field

[0001] This invention relates to the field of graders, and more specifically to a dynamic performance matching method and system for pure electric graders. Background Technology

[0002] In today's rapidly evolving technological landscape, pure electric graders, as an important member of the construction machinery industry, have demonstrated enormous potential in environmental protection and energy conservation due to their advantages such as zero emissions, low noise, and high efficiency.

[0003] In existing technologies, pure electric graders primarily achieve their movement functions through motor drive. As the core power source, the performance of the motor directly determines the overall working efficiency and work quality of the grader. However, traditional control systems often rely on preset parameters when managing these functions. This "one-size-fits-all" approach proves inadequate when facing varying working conditions and load requirements.

[0004] In practical applications, the operating actions of motor graders are complex and varied, which affects the motor's operating status and consequently the overall performance of the grader. If the control system cannot adjust in real time according to these changes in operating actions, the motor may not operate at its optimal state, resulting in low energy efficiency and slow response speed.

[0005] The problem is particularly prominent in the parameter matching between the motor of the working device and the load equipment (such as load-sensitive pumps). Traditional control systems often use fixed control strategies and cannot be dynamically adjusted according to the real-time requirements of the operation, resulting in low energy efficiency and slow response speed. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a dynamic performance matching method and system for a pure electric grader, which dynamically adjusts the motor parameters of the working device according to actual working conditions to maximize energy efficiency and optimize performance.

[0007] In a first aspect, the technical solution of the present invention provides a dynamic performance matching method for a pure electric grader, specifically including the following steps:

[0008] Obtain the hydraulic oil pressure within the hydraulic circuit;

[0009] Detect the driver's operating actions and calculate the required total hydraulic oil flow based on the driver's operating actions;

[0010] Based on the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, the motor speed corresponding to the maximum total driving efficiency of the working device is found by the cyclic optimization algorithm and recorded as the optimal motor speed.

[0011] The optimal motor speed is generated into the actual execution speed command and sent to the motor controller of the working device.

[0012] In an optional implementation, the motor speed corresponding to the maximum overall efficiency of the working device drive is found using a cyclic optimization algorithm, specifically including:

[0013] Configure the minimum motor speed, maximum motor speed, and step size;

[0014] Between the minimum and maximum motor speeds, a motor speed value is selected at every step and recorded as the target motor speed.

[0015] Calculate the motor working torque based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, and record it as the target motor working torque.

[0016] Find the motor efficiency corresponding to each group of target motor speed and target motor working torque in the motor efficiency MAP chart, and record it as the target motor efficiency.

[0017] Use the target motor speed as the target hydraulic pump speed;

[0018] Calculate the hydraulic pump's working displacement based on the target hydraulic pump speed and the required total flow rate of the hydraulic transmission medium.

[0019] Find the hydraulic pump efficiency corresponding to each target hydraulic pump speed and hydraulic pump working displacement in the hydraulic pump efficiency table, and record it as the target hydraulic pump efficiency.

[0020] Calculate the total drive efficiency of the working device based on the target motor efficiency and the target hydraulic pump efficiency, and record it as the target total drive efficiency of the working device.

[0021] Find the maximum total driving efficiency of all target working devices, and select the target motor speed corresponding to the maximum total driving efficiency as the optimal motor speed.

[0022] In an optional implementation, the motor operating torque is calculated based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit, and the required total flow rate of the hydraulic transmission medium. This calculated torque is denoted as the target motor operating torque and is specifically performed using the following formula:

[0023] Target motor operating torque = (hydraulic oil pressure in the hydraulic circuit * total required flow rate of hydraulic transmission medium) / target motor speed.

[0024] In an optional implementation, the total efficiency of the drive system is calculated based on the target motor efficiency and the target hydraulic pump efficiency, and is denoted as the target total drive system efficiency. Specifically, this includes calculation using the following formula:

[0025] The overall efficiency of the target drive system = the efficiency of the target motor * the efficiency of the target hydraulic pump.

[0026] Secondly, the technical solution of the present invention provides a dynamic performance matching system for a pure electric grader, comprising,

[0027] Hydraulic oil pressure acquisition module: acquires the hydraulic oil pressure within the hydraulic circuit;

[0028] Hydraulic oil total flow calculation module: detects the driver's operating actions and calculates the required total hydraulic oil flow based on the driver's operating actions;

[0029] Optimal motor speed acquisition module: Based on the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, the motor speed corresponding to the maximum overall driving efficiency of the working device is found through a cyclic optimization algorithm and recorded as the optimal motor speed.

[0030] Command issuing module: Generates the actual execution speed command from the optimal motor speed and issues it to the motor controller of the working device.

[0031] In an optional implementation, the optimal motor speed acquisition module finds the motor speed corresponding to the maximum overall driving efficiency of the working device through a cyclic optimization algorithm, specifically including:

[0032] Configure the minimum motor speed, maximum motor speed, and step size;

[0033] Between the minimum and maximum motor speeds, a motor speed value is selected at every step and recorded as the target motor speed.

[0034] Calculate the motor working torque based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, and record it as the target motor working torque.

[0035] Find the motor efficiency corresponding to each group of target motor speed and target motor working torque in the motor efficiency MAP chart, and record it as the target motor efficiency.

[0036] Use the target motor speed as the target hydraulic pump speed;

[0037] Calculate the hydraulic pump's working displacement based on the target hydraulic pump speed and the required total flow rate of the hydraulic transmission medium.

[0038] Find the hydraulic pump efficiency corresponding to each target hydraulic pump speed and hydraulic pump working displacement in the hydraulic pump efficiency table, and record it as the target hydraulic pump efficiency.

[0039] Calculate the total drive efficiency of the working device based on the target motor efficiency and the target hydraulic pump efficiency, and record it as the target total drive efficiency of the working device.

[0040] Find the maximum total driving efficiency of all target working devices, and select the target motor speed corresponding to the maximum total driving efficiency as the optimal motor speed.

[0041] In an optional implementation, the motor operating torque is calculated based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit, and the required total flow rate of the hydraulic transmission medium. This calculated torque is denoted as the target motor operating torque and is specifically performed using the following formula:

[0042] Target motor operating torque = (hydraulic oil pressure in the hydraulic circuit * total required flow rate of hydraulic transmission medium) / target motor speed.

[0043] In an optional implementation, the total efficiency of the drive system is calculated based on the target motor efficiency and the target hydraulic pump efficiency, and is denoted as the target total drive system efficiency. Specifically, this includes calculation using the following formula:

[0044] The overall efficiency of the target drive system = the efficiency of the target motor * the efficiency of the target hydraulic pump.

[0045] The present invention provides a dynamic performance matching method and system for a pure electric grader, which has the following advantages over the prior art: the optimal motor speed is calculated in real time based on the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, so as to realize the adjustment of the motor speed of the working device according to different operating conditions, thereby maximizing energy efficiency and optimizing performance, ensuring that the optimal efficiency can be achieved under different operating conditions, so that the motor always operates in the best efficiency range, thereby optimizing energy utilization, reducing energy consumption, and extending equipment life. Attached Figure Description

[0046] To more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a schematic diagram showing the connection between the working device motor (PMSM) and the load-sensitive pump (LS pump).

[0048] Figure 2 This is a schematic diagram of a dynamic performance matching method for a pure electric grader provided in an embodiment of the present invention.

[0049] Figure 3 This is a flowchart illustrating a specific embodiment of the automatic speed control of the motor of the working device.

[0050] Figure 4This is a schematic diagram of the automatic speed control principle for the working device motor, based on optimal efficiency.

[0051] Figure 5 This is a simplified schematic diagram of the automatic speed control principle for the working device motor, based on optimal efficiency.

[0052] Figure 6 This is a schematic block diagram of a dynamic performance matching system for a pure electric grader provided in an embodiment of the present invention. Detailed Implementation

[0053] To enable those skilled in the art to better understand the present invention, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0055] The control system hardware of the pure electric grader in this embodiment of the invention includes a main controller and a working device motor controller, both connected to a CAN network and communicating via the CAN network. The main controller performs automatic speed control of the working device motor to achieve optimal efficiency, detects the pressure of the hydraulic oil in the hydraulic circuit and the driver's operation, calculates the required flow rate, and finds the optimal efficiency of the working device motor through a certain algorithm.

[0056] This invention provides a dynamic performance matching method for a pure electric motor grader. Through automatic speed control of the working device motor, it improves the ease of operation and safety of the pure electric motor grader, while also significantly increasing energy efficiency and mechanical lifespan. The automatic speed control of the working device motor is described in detail below.

[0057] Figure 1 This is a schematic diagram of the connection between the working device motor (PMSM) and the load-sensitive pump (LS pump). The working device refers to devices such as the blade. The automatic speed control process of the working device motor is that the main controller controls the speed of the working device motor according to the operation of the working device.

[0058] Figure 2 This is a schematic flowchart of a dynamic performance matching method for a pure electric grader provided in an embodiment of the present invention. Dynamic performance matching is achieved based on the automatic speed control of the motor of the working device. Wherein, Figure 2 The executing entity can be a dynamic performance matching system for a pure electric grader. The dynamic performance matching method for a pure electric grader provided in this embodiment of the invention is executed by a computer device; correspondingly, the dynamic performance matching system for the pure electric grader runs within the computer device. Depending on different requirements, the order of the steps in this flowchart can be changed, and some steps can be omitted.

[0059] like Figure 2 As shown, the method specifically includes the following steps.

[0060] S101, obtain the hydraulic oil pressure in the hydraulic circuit.

[0061] like Figure 4 As shown, in an optional embodiment, the hydraulic oil pressure in the hydraulic circuit is detected by a pressure sensor.

[0062] like Figure 5 As shown, in an optional implementation, since the hydraulic oil pressure in the hydraulic circuit varies greatly and is highly random, and relies on sensors, for the sake of simplicity and to meet engineering needs, the current pressure signal may not be detected, and the pressure may be taken as a typical value, such as the hydraulic oil pressure in the hydraulic circuit. When configuring the hydraulic oil pressure in the reference hydraulic circuit, the fixed value is set as follows: without setting a pressure sensor, the pressure value is set to 18 MPa in the algorithm (software). 18 MPa is the hydraulic oil pressure value under typical operating conditions of the grader (the hydraulic oil pressure value is different under typical operating conditions of different graders). In this embodiment, it is 18 MPa.

[0063] S102 detects the driver's operating actions and calculates the required total hydraulic oil flow based on the driver's operating actions.

[0064] The operator's actions include lifting, tilting, adjusting the angle, and side-moving the shovel. The total flow rate of the combined actions (N actions) performed by the operator is the required total hydraulic oil flow rate. The total hydraulic oil flow rate is obtained by summing the hydraulic oil flow rates of each action. The hydraulic oil flow rate can be measured by a flow sensor.

[0065] S103, based on the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, finds the motor speed corresponding to the maximum overall driving efficiency of the working device through a cyclic optimization algorithm, and records it as the optimal motor speed.

[0066] S103.1, configures the minimum motor speed, maximum motor speed, and step size.

[0067] S103.2, Within the range between the minimum and maximum motor speeds, select a motor speed value at every step increment, and record it as the target motor speed.

[0068] S103.3 Calculate the motor working torque based on the target motor speed, hydraulic oil pressure in the hydraulic circuit and the required total flow rate of the hydraulic transmission medium, and record it as the target motor working torque.

[0069] Target motor operating torque = (hydraulic oil pressure in the hydraulic circuit * total required flow rate of hydraulic transmission medium) / target motor speed.

[0070] S103.4 Find the motor efficiency corresponding to the target motor speed and target motor working torque for each group in the motor efficiency MAP chart, and record it as the target motor efficiency.

[0071] S103.5, the target motor speed is used as the target hydraulic pump speed.

[0072] S103.6 Calculate the working displacement of the hydraulic pump based on the target hydraulic pump speed and the required total flow rate of the hydraulic transmission medium.

[0073] S103.7, find the hydraulic pump efficiency corresponding to the target hydraulic pump speed and hydraulic pump working displacement in the hydraulic pump efficiency table, and record it as the target hydraulic pump efficiency.

[0074] S103.8 Calculate the total drive efficiency of the working device based on the target motor efficiency and the target hydraulic pump efficiency, and record it as the target total drive efficiency of the working device.

[0075] The overall efficiency of the target drive system = the efficiency of the target motor * the efficiency of the target hydraulic pump.

[0076] S103.9 Find the maximum total driving efficiency of all target working devices, and select the target motor speed corresponding to the maximum total driving efficiency of the working devices as the optimal motor speed.

[0077] S104 generates the actual execution speed command from the optimal motor speed and sends it to the motor controller of the working device.

[0078] The main controller executes the above steps and sends the speed command to the motor controller of the working device. Figure 3 This is a flowchart illustrating a specific embodiment of automatic speed control for the motors of a working device. In this embodiment, the motor efficiency generated by the speed of all motors is considered. and LS pump efficiency The simulation is performed, and then an optimal value is found from the results. Here Below, the product of the efficiency of the working device motor and the LS pump. The rotational speed reaches its maximum. Since the rotational speed is a continuous value, its range can be defined and discretized to reduce computational load, which has little impact on the result.

[0079] Working device motor speed These are the variables that need to be traversed in the optimization algorithm. To simplify the calculation, the rotation speed can be started from the minimum. To the maximum A value is taken at fixed intervals within the range, for example, a step size of 100 rpm. It is a discrete array The minimum rotational speed can be determined by the flow rate requirement. The flow requirement is calculated based on the pump's maximum displacement. The flow rate requirement can be calculated by detecting the driver's actions and using the corresponding hydraulic cylinder parameters. For example, if the driver performs a complex action consisting of N movements, the flow rate requirement is... .

[0080] Working device motor torque From the formula The efficiency of the motor in the working device is calculated. Its operating speed and working torque Related. According to and Find the motor efficiency in the motor efficiency map. LS pump operating speed LS pump operating displacement It is a self-adjusting quantity based on flow demand and load pressure, and can be adjusted according to... The operating pressure of the LS pump was calculated. As measured by the pressure sensor, the efficiency of the LS pump is related to its operating displacement. Operating speed and work pressure The correlation is used to calculate the efficiency of the LS pump. The overall efficiency of the working device drive is: .

[0081] The above text provides a detailed description of an embodiment of a dynamic performance matching method for a pure electric grader. Based on the dynamic performance matching method for a pure electric grader described in the above embodiment, this invention also provides a dynamic performance matching system for a pure electric grader corresponding to the method.

[0082] Figure 6 This is a schematic block diagram of a dynamic performance matching system for a pure electric motor grader provided in an embodiment of the present invention. In this embodiment, the dynamic performance matching system 200 for the pure electric motor grader can be divided into multiple functional modules according to the functions it performs, such as... Figure 6As shown. The functional modules may include: a hydraulic oil pressure acquisition module, a hydraulic oil total flow calculation module, an optimal motor speed acquisition module, and an instruction issuance module. The module referred to in this invention is a series of computer program segments that can be executed by at least one processor and perform a fixed function, and is stored in memory.

[0083] Hydraulic oil pressure acquisition module: acquires the hydraulic oil pressure within the hydraulic circuit;

[0084] Hydraulic oil total flow calculation module: detects the driver's operating actions and calculates the required total hydraulic oil flow based on the driver's operating actions;

[0085] Optimal motor speed acquisition module: Based on the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, the motor speed corresponding to the maximum overall driving efficiency of the working device is found through a cyclic optimization algorithm and recorded as the optimal motor speed.

[0086] Command issuing module: Generates the actual execution speed command from the optimal motor speed and issues it to the motor controller of the working device.

[0087] In an optional implementation, the optimal motor speed acquisition module finds the motor speed corresponding to the maximum overall driving efficiency of the working device through a cyclic optimization algorithm, specifically including:

[0088] Configure the minimum motor speed, maximum motor speed, and step size;

[0089] Between the minimum and maximum motor speeds, a motor speed value is selected at every step and recorded as the target motor speed.

[0090] Calculate the motor working torque based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the total flow rate of the required hydraulic transmission medium, and record it as the target motor working torque.

[0091] Find the motor efficiency corresponding to each group of target motor speed and target motor working torque in the motor efficiency MAP chart, and record it as the target motor efficiency.

[0092] Use the target motor speed as the target hydraulic pump speed;

[0093] Calculate the hydraulic pump's working displacement based on the target hydraulic pump speed and the required total flow rate of the hydraulic transmission medium.

[0094] Find the hydraulic pump efficiency corresponding to each target hydraulic pump speed and hydraulic pump working displacement in the hydraulic pump efficiency table, and record it as the target hydraulic pump efficiency.

[0095] Calculate the total drive efficiency of the working device based on the target motor efficiency and the target hydraulic pump efficiency, and record it as the target total drive efficiency of the working device.

[0096] Find the maximum total driving efficiency of all target working devices, and select the target motor speed corresponding to the maximum total driving efficiency as the optimal motor speed.

[0097] In an optional implementation, the motor operating torque is calculated based on the target motor speed, the hydraulic oil pressure in the hydraulic circuit, and the required total flow rate of the hydraulic transmission medium. This calculated torque is denoted as the target motor operating torque and is specifically performed using the following formula:

[0098] Target motor operating torque = (hydraulic oil pressure in the hydraulic circuit * total required flow rate of hydraulic transmission medium) / target motor speed.

[0099] In an optional implementation, the total efficiency of the drive system is calculated based on the target motor efficiency and the target hydraulic pump efficiency, and is denoted as the target total drive system efficiency. Specifically, this includes calculation using the following formula:

[0100] The overall efficiency of the target drive system = the efficiency of the target motor * the efficiency of the target hydraulic pump.

[0101] In one optional implementation, the hydraulic oil pressure acquisition module acquires the hydraulic oil pressure in the hydraulic circuit, specifically including: configuring the hydraulic oil pressure in the reference hydraulic circuit and storing the hydraulic oil pressure in the reference hydraulic circuit in the storage area; and retrieving the hydraulic oil pressure in the reference hydraulic circuit from the storage area.

[0102] The pure electric grader dynamic performance matching system of this embodiment is used to implement the aforementioned pure electric grader dynamic performance matching method. Therefore, the specific implementation of this system can be found in the embodiment section of the operation and maintenance method based on time series data trend prediction mentioned above. So, its specific implementation can be referred to the description of the corresponding embodiments, and will not be described in detail here.

[0103] Furthermore, since the pure electric grader dynamic performance matching system of this embodiment is used to implement the aforementioned pure electric grader dynamic performance matching method, its function corresponds to the function of the above method, and will not be repeated here.

Claims

1. A method for dynamic performance matching of a pure electric grader, characterized in that, Specifically comprising the following steps: Obtaining the hydraulic oil pressure in the hydraulic circuit; Detecting the driver operation action and calculating the required total flow of hydraulic oil according to the driver operation action; Based on the hydraulic oil pressure in the hydraulic circuit and the required total flow of hydraulic transmission medium, the maximum working device driving total efficiency corresponding motor speed is found out through a cyclic optimization algorithm, which is recorded as the optimal motor speed; The optimal motor speed generates an actual execution speed instruction, which is sent to the working device motor controller; The maximum working device driving total efficiency corresponding motor speed is found out through a cyclic optimization algorithm, specifically including: Configure the minimum motor speed, the maximum motor speed and the step length; Between the minimum motor speed and the maximum motor speed, every other step selects a motor speed value, which is recorded as the target motor speed; According to the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the required total flow of hydraulic transmission medium, the motor working torque is calculated, which is recorded as the target motor working torque; In the motor efficiency MAP, the motor efficiency corresponding to each group of target motor speed and target motor working torque is found out, which is recorded as the target motor efficiency; The target motor speed is taken as the target hydraulic pump speed; According to the target hydraulic pump speed and the required total flow of hydraulic transmission medium, the hydraulic pump working displacement is calculated; In the hydraulic pump efficiency table, the hydraulic pump efficiency corresponding to each group of target hydraulic pump speed and hydraulic pump working displacement is found out, which is recorded as the target hydraulic pump efficiency; According to the target motor efficiency and the target hydraulic pump efficiency, the working device driving total efficiency is calculated, which is recorded as the target working device driving total efficiency; Among all the target working device driving total efficiencies, the maximum working device driving total efficiency is found out, and the target motor speed corresponding to the maximum working device driving total efficiency is selected as the optimal motor speed.

2. The method of claim 1, wherein, According to the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the required total flow of hydraulic transmission medium, the motor working torque is calculated, which is recorded as the target motor working torque, specifically including calculating through the following formula: Target motor working torque = (hydraulic oil pressure in the hydraulic circuit * required total flow of hydraulic transmission medium) / target motor speed.

3. The method of claim 1, wherein, According to the target motor efficiency and the target hydraulic pump efficiency, the driving system total efficiency is calculated, which is recorded as the target driving system total efficiency, specifically including calculating through the following formula: Target driving system total efficiency = target motor efficiency * target hydraulic pump efficiency.

4. A pure electric motor grader dynamic performance matching system, characterized in that, Including, The hydraulic oil pressure acquisition module acquires the hydraulic oil pressure in the hydraulic circuit; The hydraulic oil total flow calculation module detects the driver operation action and calculates the required total flow of hydraulic oil according to the driver operation action; The optimal motor speed acquisition module finds out the motor speed corresponding to the maximum working device driving total efficiency based on the hydraulic oil pressure in the hydraulic circuit and the required total flow of hydraulic transmission medium through a cyclic optimization algorithm, which is recorded as the optimal motor speed; The instruction sending module generates an actual execution speed instruction from the optimal motor speed, which is sent to the working device motor controller; The optimal motor speed acquisition module finds out the motor speed corresponding to the maximum working device driving total efficiency through a cyclic optimization algorithm, specifically including: Configure the minimum motor speed, the maximum motor speed and the step length; In the minimum motor speed and the maximum motor speed range, every step is selected as a motor speed value, recorded as the target motor speed; According to the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the required total flow of the hydraulic transmission medium, the motor working torque is calculated, recorded as the target motor working torque; In the motor efficiency MAP, the motor efficiency corresponding to each group of target motor speed and target motor working torque is found, recorded as the target motor efficiency; The target motor speed is taken as the target hydraulic pump speed; According to the target hydraulic pump speed and the required total flow of the hydraulic transmission medium, the hydraulic pump working displacement is calculated; In the hydraulic pump efficiency table, the hydraulic pump efficiency corresponding to each group of target hydraulic pump speed and hydraulic pump working displacement is found, recorded as the target hydraulic pump efficiency; According to the target motor efficiency and the target hydraulic pump efficiency, the total efficiency of the working device drive is calculated, recorded as the target total efficiency of the working device drive; In all target total efficiencies of the working device drive, the maximum total efficiency of the working device drive is found, and the target motor speed corresponding to the maximum total efficiency of the working device drive is selected as the optimal motor speed.

5. The pure electric motor grader dynamic performance matching system according to claim 4, characterized in that, According to the target motor speed, the hydraulic oil pressure in the hydraulic circuit and the required total flow of the hydraulic transmission medium, the motor working torque is calculated, recorded as the target motor working torque, specifically including calculating through the following formula: Target motor working torque=(hydraulic oil pressure in the hydraulic circuit*required total flow of the hydraulic transmission medium) / target motor speed.

6. The pure electric motor grader dynamic performance matching system according to claim 4, characterized in that, According to the target motor efficiency and the target hydraulic pump efficiency, the total efficiency of the drive system is calculated, recorded as the target total efficiency of the drive system, specifically including calculating through the following formula: Target total efficiency of the drive system=target motor efficiency*target hydraulic pump efficiency.

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