Load-adaptive cooperative control method and system for electrically-driven double pumps

Abstract

The invention discloses a load self-adaptive cooperative control method and system for electric drive double pumps. The method comprises the steps that the target flow of a first pump and the target flow of a second pump in the double pumps are obtained; dividing a plurality of rotating speed working points; calculating a steady-state torque corresponding to the rotating speed working point; calculating a motor target torque corresponding to the rotating speed working point; calculating a comprehensive efficiency value; the comprehensive efficiency values are sequentially sorted from high to low, optimal solution screening is sequentially carried out from the motor target torque corresponding to the highest comprehensive efficiency value, the first pump displacement value and the second pump displacement value, and when a preset stepping value range is met, optimal solution screening is carried out; and outputting the motor target torque of the comprehensive efficiency value, the first pump displacement value and the second pump displacement value as final execution target values. The method has the advantages that optimal solution screening is carried out through the comprehensive efficiency value and the stepping value judgment condition, and high system efficiency is obtained on the basis that the system flow requirement is met; the method can reduce the sudden change of the rotating speed of the motor caused by the load change, and improves the responsiveness and stability of the rotating speed.

Description

Technical Field

[0001] The present invention relates to a load-adaptive coordinated control method and system for an electric-driven double pump, belonging to the technical field of new energy engineering machinery. Background Art

[0002] Non-road vehicles represented by construction machinery are gradually becoming cleaner, more electrified, and more high-tech. As the new energy source that has received the most attention at present, the application and value of new energy in the field of construction machinery are gradually becoming more prominent. It provides more efficient, environmentally friendly, and energy-saving solutions for engineering construction, and helps the electrification and intelligent development of construction machinery. Excavators play an important role in engineering construction and maintain a growth trend. The electrification of excavators continues to accelerate. At present, the configuration commonly used by electric excavators is the oil-to-electric method, that is, the electric motor replaces the engine as the power source, and the traditional hydraulic system remains unchanged. Although the efficiency of the whole machine has been improved on the basis of the fuel model, the overall energy efficiency is low, the cost is high, and the competitiveness is weaker than the traditional model. It is urgent to upgrade the technical architecture.

[0003] The electrification of excavators has promoted the application of electric drive pump technology in excavators. Compared with traditional engine-driven hydraulic systems, motors have a wider speed regulation range, higher efficiency and faster response, making it possible to meet the flow requirements of hydraulic systems through variable speed control or dual variable control of variable speed combined with variable displacement, which has broad application scenarios.

[0004] In view of the electrification of the hydraulic drive system of the excavator, the existing technology has realized the application of motor-driven pumps and control methods on the excavator. However, the electric drive pump system only controls the single variable of speed or displacement, and does not adopt the dual variable control strategy of flow and displacement. The overall efficiency of the system cannot be optimized, and the load pressure size is not taken into account when adjusting the motor speed. The responsiveness of the system still needs to be improved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a load-adaptive collaborative control method and system for an electric-driven double pump.

[0006] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0007] On the one hand, the present invention discloses a load adaptive coordinated control method of an electric drive double pump, comprising: Obtaining a target flow rate of pump one and a target flow rate of pump two in a double pump; Determine the motor speed range according to the target flow rate of pump one and the target flow rate of pump two, and divide a plurality of speed operating points according to the motor speed range; Calculate the steady-state torque corresponding to each speed operating point based on the motor speed at each speed operating point; The steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and the dynamic adjustment torque is obtained by closed-loop calculation as the motor target torque corresponding to the current speed operating point; Based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point, the motor efficiency value is obtained; based on the motor speed at the current speed operating point and the obtained pump one load pressure and pump one displacement values, the pump one efficiency value is determined; based on the motor speed at the current speed operating point and the obtained pump two load pressure and pump two displacement values, the pump two efficiency value is determined; based on the motor efficiency value, pump one efficiency value and pump two efficiency value, the comprehensive efficiency value is calculated; The comprehensive efficiency values ​​corresponding to the multiple speed operating points are sorted in order from high to low, and the optimal solutions are screened starting from the motor target torque and pump one displacement value and pump two displacement value corresponding to the highest comprehensive efficiency value. When the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value meet the preset step value range, the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value are output as the final target value for execution.

[0008] Further, the step of obtaining a target flow rate of pump one and a target flow rate of pump two in the double pump includes: When the change ∆Q1 between the current flow request of pump one and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump two and the flow request at the previous moment exceeds the set threshold, the target flow Q1 of pump one and the target flow Q2 of pump two are updated to the current flow request of the corresponding pump, otherwise the target flow Q1 of pump one and the target flow Q2 of pump two are the flow request of the corresponding pump at the previous moment.

[0009] Furthermore, the motor speed range is determined according to the target flow rate of the pump 1 and the target flow rate of the pump 2, and a plurality of speed operating points are divided according to the motor speed range, including: According to the target flow rate Q1 of pump one, the target flow rate Q2 of pump two and the maximum speed Spd of the motor obtained max , the minimum and maximum displacement values ​​of pump 1 and pump 2 are Dpl min 、Dpl max Screening to obtain the motor speed range that meets the flow requirements [Spd low Sd up ], Sd low =max(Q1 / Dpl max , Q2 / Dpl max ); Sd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spdmax ); Where, Spd low The minimum speed value to meet the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2, Spd up The maximum speed value that satisfies both the target flow rate Q1 of pump one and the target flow rate Q2 of pump two; In the motor speed range [Spd low Sd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N ,Spd i Represents the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, N is the total number of speed operating points.

[0010] Furthermore, the calculation formula of the steady-state torque corresponding to the speed operating point is: T si (k) = P1(k) * DpD 1i (k)+ P2(k) * DpD 2i (k); Where, T si (k) is the steady-state torque corresponding to the i-th speed operating point of the current execution cycle k, P1(k) is the load pressure of pump 1 in the current execution cycle k, P2(k) is the load pressure of pump 2 in the current execution cycle k, Dpl 1i (k) is the pump displacement value of the i-th speed operating point in the current execution cycle k, Dpl 2i (k) is the value of the pump displacement at the i-th speed operating point in the current execution cycle k.

[0011] Furthermore, the steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and the closed-loop calculation is performed to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point, including: According to the speed Spd of the current i-th speed operating point i The actual motor speed Spd collected real (k) Calculate the speed difference ∆Spd(k); A PID algorithm is used to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), and in the process of using the PID algorithm to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into several intervals in combination with the speed difference ∆Spd(k), and each interval corresponds to a set of proportional parameters, integral parameters, and differential parameters.

[0012] Furthermore, the calculation formula of the motor target torque is: Ti (k) = T di (k)+ T si (k); Where, T i (k) is the speed Spd of the i-th speed operating point in the current execution cycle k i The corresponding motor target torque, T d (k) is the adjustment torque requirement corresponding to the i-th speed operating point of the current execution cycle k; ; Where P is the proportional parameter in the PID algorithm, I is the integral parameter I in the PID algorithm, D is the differential parameter in the PID algorithm, ∆Spd(k) and ∆Spd(k-1) are the differences between the motor target speed and the actual speed in the kth and k-1th execution cycles respectively, and ∆Spd(j) is the speed deviation of a cycle before the kth program cycle, where j ranges from 0, 1, 2, …, k.

[0013] Furthermore, the calculation formula of the comprehensive efficiency value is: ; Where Eff i (k) is the comprehensive efficiency value of the i-th speed operating point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed operating point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed operating point in the current execution cycle k, Eff p1i (k) is the pump efficiency value of the i-th speed working point in the current execution cycle k, Eff p2i (k) is the efficiency value of pump 2 at the i-th speed operating point in the current execution cycle k, Eff mi (k) is the motor efficiency value of the i-th speed operating point in the current execution cycle k.

[0014] In a second aspect, the present invention discloses a load-adaptive coordinated control system of an electric drive double pump, comprising a hydraulic controller, an electric drive assembly, a first pump, a second pump, a first pressure sensor, a second pressure sensor, and a coordinated controller; The hydraulic controller outputs the flow requirements of pump 1 and pump 2 to the collaborative controller according to the action requirements of the hydraulic actuator at the rear end of the excavator; The electric drive assembly is a component assembly integrating a motor and a motor controller, and is used as a power source for a double pump, wherein the double pump comprises a pump 1 and a pump 2, and the rotors of the pump 1 and the pump 2 are driven to rotate synchronously by the output shaft of the motor; The first pressure sensor and the second pressure sensor respectively collect the load pressure of the output port of the pump 1 and the load pressure of the output port of the pump 2; The collaborative controller receives the flow demand of pump one and the flow demand of pump two and the actual speed of the motor, and reads the load pressure of pump one and pump two collected by the pressure sensor, calculates and outputs the motor torque command and the displacement command of pump one and pump two, which are the optimal efficiency values ​​of the comprehensive efficiency of pump one working efficiency, pump two working efficiency and motor working efficiency, and performs collaborative control of the electric-driven dual pumps through the motor torque command and the displacement command of pump one and pump two.

[0015] In a third aspect, the present invention discloses a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, which, when executed by a computing device, cause the computing device to perform the method of the first aspect.

[0016] In a fourth aspect, the present invention discloses a computer device, comprising: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing the method of the first aspect.

[0017] The beneficial effects achieved by the present invention are: The efficiency value of the motor torque and pump displacement combination that simultaneously meets the flow requirements of pump one and pump two is calculated by traversing the speed values, and the torque and displacement change step values ​​are set to further screen out the optimal efficiency combination that can be met by the motor and pump response characteristics, thereby obtaining a higher system efficiency while meeting the system flow requirements.

[0018] The motor torque demand is the feedforward torque calculated by taking the load pressure and displacement values ​​of pump one and pump two and the regulating torque calculated by closed-loop according to the speed deviation. The closed-loop control parameters are adjusted in real time considering the speed difference, thereby reducing the sudden change of motor speed caused by load changes and improving speed responsiveness and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the composition diagram of the electric drive double pump load adaptive cooperative control system; Figure 2 It is a flow chart of the load adaptive collaborative control method of electric drive double pumps. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0021] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0022] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0023] Embodiment 1: This embodiment introduces a load adaptive coordinated control method of an electric drive double pump, including: Obtaining a target flow rate of pump one and a target flow rate of pump two in a double pump; Determine the motor speed range according to the target flow rate of pump one and the target flow rate of pump two, and divide a plurality of speed operating points according to the motor speed range; Calculate the steady-state torque corresponding to each speed operating point based on the motor speed at each speed operating point; The steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and the dynamic adjustment torque is obtained by closed-loop calculation as the motor target torque corresponding to the current speed operating point; Based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point, the motor efficiency value is obtained; based on the motor speed at the current speed operating point and the obtained pump one load pressure and pump one displacement values, the pump one efficiency value is determined; based on the motor speed at the current speed operating point and the obtained pump two load pressure and pump two displacement values, the pump two efficiency value is determined; based on the motor efficiency value, pump one efficiency value and pump two efficiency value, the comprehensive efficiency value is calculated; The comprehensive efficiency values ​​corresponding to the multiple speed operating points are sorted in order from high to low, and the optimal solutions are screened starting from the motor target torque and pump one displacement value and pump two displacement value corresponding to the highest comprehensive efficiency value. When the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value meet the preset step value range, the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value are output as the final target value for execution.

[0024] The step of obtaining a target flow rate of pump one and a target flow rate of pump two in the double pump comprises: When the change ∆Q1 between the current flow request of pump one and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump two and the flow request at the previous moment exceeds the set threshold, the target flow Q1 of pump one and the target flow Q2 of pump two are updated to the current flow request of the corresponding pump, otherwise the target flow Q1 of pump one and the target flow Q2 of pump two are the flow request of the corresponding pump at the previous moment.

[0025] The motor speed range is determined according to the target flow rate of the pump 1 and the target flow rate of the pump 2, and a plurality of speed operating points are divided according to the motor speed range, including: According to the target flow rate Q1 of pump one, the target flow rate Q2 of pump two and the maximum speed Spd of the motor obtained max , the minimum and maximum displacement values ​​of pump 1 and pump 2 are Dpl min 、Dpl max Screening to obtain the motor speed range that meets the flow requirements [Spd low Sd up ], Sd low =max(Q1 / Dpl max , Q2 / Dpl max ); Sd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spd max ); Where, Spd low The minimum speed value to meet the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2, Spd up The maximum speed value that satisfies both the target flow rate Q1 of pump one and the target flow rate Q2 of pump two; In the motor speed range [Spd low Sd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N ,Spd iRepresents the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, N is the total number of speed operating points.

[0026] The calculation formula of the steady-state torque corresponding to the speed operating point is: T si (k) = P1(k) * DpD 1i (k)+ P2(k) * DpD 2i (k); Where, T si (k) is the steady-state torque corresponding to the i-th speed operating point of the current execution cycle k, P1(k) is the load pressure of pump 1 in the current execution cycle k, P2(k) is the load pressure of pump 2 in the current execution cycle k, Dpl 1i (k) is the pump displacement value of the i-th speed operating point in the current execution cycle k, Dpl 2i (k) is the value of the pump displacement at the i-th speed operating point in the current execution cycle k.

[0027] The method of superimposing the speed difference on the steady-state torque corresponding to the current speed operating point and performing closed-loop calculation to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point includes: According to the speed Spd of the current i-th speed operating point i The actual motor speed Spd collected real (k) Calculate the speed difference ∆Spd(k); A PID algorithm is used to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), and in the process of using the PID algorithm to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into several intervals in combination with the speed difference ∆Spd(k), and each interval corresponds to a set of proportional parameters, integral parameters, and differential parameters.

[0028] The calculation formula of the motor target torque is: T i (k) = T di (k)+ T si (k); Where, T i (k) is the speed Spd of the i-th speed operating point in the current execution cycle k i The corresponding motor target torque, T d (k) is the adjustment torque requirement corresponding to the i-th speed operating point of the current execution cycle k; ; Where P is the proportional parameter in the PID algorithm, I is the integral parameter I in the PID algorithm, D is the differential parameter in the PID algorithm, ∆Spd(k) and ∆Spd(k-1) are the differences between the motor target speed and the actual speed in the kth and k-1th execution cycles respectively, and ∆Spd(j) is the speed deviation of a cycle before the kth program cycle, where j ranges from 0, 1, 2, …, k.

[0029] The calculation formula of the comprehensive efficiency value is: ; Where Eff i (k) is the comprehensive efficiency value of the i-th speed operating point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed operating point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed operating point in the current execution cycle k, Eff p1i (k) is the pump efficiency value of the i-th speed working point in the current execution cycle k, Eff p2i (k) is the efficiency value of pump 2 at the i-th speed operating point in the current execution cycle k, Eff mi (k) is the motor efficiency value of the i-th speed operating point in the current execution cycle k.

[0030] In this embodiment, the efficiency value of the motor torque and pump displacement combination that simultaneously meets the flow requirements of pump one and pump two is calculated by speed traversal value taking, and the torque and displacement change step values ​​are set to further screen out the optimal efficiency combination that can be met by the motor and pump response characteristics, thereby obtaining a higher system efficiency while meeting the system flow requirements; the motor torque requirement is the feedforward torque calculated by taking the load pressure and displacement values ​​of pump one and pump two, superimposed on the adjustment torque calculated by the speed deviation PID closed loop, wherein the PID closed-loop control parameters are adjusted in real time considering the speed difference, thereby reducing the sudden change in motor speed caused by load changes and improving speed responsiveness and stability.

[0031] Embodiment 2: This embodiment introduces a load-adaptive coordinated control system for electric-driven double pumps. The system structure is as follows: Figure 1As shown, it includes a hydraulic controller, an electric drive assembly, pump 1, pump 2, a first pressure sensor, a second pressure sensor, a cooperative controller, etc. The hydraulic controller outputs the flow requirements of pump 1 and pump 2 to the cooperative controller according to the action requirements of the hydraulic actuator at the rear end of the excavator; the electric drive assembly is a component assembly that integrates the motor and the motor controller, and is the power source of the double pump; pump 1 and pump 2 together constitute a double pump, and the rotors of the two pumps are driven by the motor output shaft to rotate synchronously; the first pressure sensor and the second pressure sensor respectively collect the load pressure of the output port of pump 1 and pump 2; the cooperative controller receives the flow requirements of pump 1 and pump 2 and the actual speed of the motor, and reads the load pressure of pump 1 and pump 2 collected by the pressure sensor, and calculates and outputs the motor torque command and the displacement command of pump 1 and pump 2 according to the above signals to realize the cooperative control of the electric drive double pump system.

[0032] Example 3 is based on the same inventive concept as Example 1. This example introduces a coordinated control method for load adaptation of an electric-driven double pump, which is applied to the coordinated control system for load adaptation of an electric-driven double pump in Example 2. The control process is as follows: Figure 2 As shown, the control of the electric drive double pump can be specifically divided into five steps: working speed point selection, speed point corresponding steady-state torque calculation, speed point corresponding target torque calculation, speed point corresponding system efficiency calculation, and optimal solution screening, as shown below: S1: Working speed selection point (11) When the change ∆Q1 between the current flow request of pump 1 and the flow request of the previous moment or the change ∆Q2 between the current flow request of pump 2 and the flow request of the previous moment exceeds the set threshold, the target flow rates Q1 and Q2 of pump 1 and pump 2 are updated to the current flow request, otherwise the target flow rate is the flow request of the previous moment.

[0033] (2) According to the target flow rates Q1 and Q2, the maximum motor speed Spd max , the minimum and maximum displacement values ​​of pump 1 and pump 2 are Dpl min 、Dpl max Screen the motor speed range that can meet the flow requirements [Spd low Sd up ].

[0034] Sd low =max(Q1 / Dpl max , Q2 / Dpl max ); Sd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spd max ); (3) In the speed range [Spd low Sdup ] Set the speed working point at equal intervals: Spd1, Spd2...Spd 100 .

[0035] S2: Calculation of steady-state torque corresponding to the speed point Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 Any one of them, the following is the speed point Spd in the kth program execution cycle i The corresponding steady-state torque is calculated.

[0036] (21) According to the kth program execution cycle, the target flow rates of pump 1 and pump 2 are Q1(k) and Q2(k), and the current speed value Spd i Calculate the corresponding pump 1 and pump 2 displacement values ​​Dpl 1i (k), Dpl 2i (k); DpD 1i (k) = Q1(k) / Spd i (k); DpD 2i (k) = Q2(k) / Spd i (k); (22) According to the current pump 1 and pump 2 load pressure P1(k), P2(k) and displacement value Dpl 1i 、Dpl 2i (k) Calculate the motor's required steady-state torque T si (k); T si (k) = P1(k) * DpD 1i (k)+ P2(k) * DpD 2i (k); S3: Calculation of target torque corresponding to the speed point Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 Any one of them, the following is the speed point Spd in the kth program execution cycle i The corresponding target torque is calculated; (31) Take the value Spd according to the current speed i and actual speed Spd real (k) Calculate the speed difference ∆Spd(k); (32) The PID algorithm is used to calculate the motor adjustment torque required to eliminate the speed difference. In order to improve the response performance of the motor speed under different working conditions, the PID parameters are divided into 4 intervals in combination with the speed difference ∆Spd(k). Each interval corresponds to a set of proportional parameters P, integral parameters I, and differential parameters D. In this way, the larger the speed difference, the larger the calculated output adjustment torque, thereby providing torque adjustment control accuracy. The specific calculation method is as follows: ; Where k is the control system program execution cycle count, T d (k) is the adjustment torque requirement of the kth program execution cycle; ∆Spd(k) and ∆Spd(k-1) are the differences between the motor target speed and the actual speed in the kth and k-1th program execution cycles, respectively. The selection of P, I, and D parameters usually needs to be calibrated based on actual vehicle tests. The following is a set of reference values ​​in the implementation process, as shown in Table 1.

[0037] Table 1 (33) The current speed point Spd at the final k moment i The corresponding target torque T i (k) is: T i (k) = T di (k)+ T si (k); Through this method, the steady-state torque corresponding to the load pressure of pump one and pump two at the current speed point is used as the feedforward torque, and the dynamic adjustment torque calculated by closed-loop calculation based on the speed difference is superimposed as the target torque corresponding to the current speed point. At the same time, the influence of load pressure change and speed difference on response performance is considered, which can improve the speed control accuracy and response speed.

[0038] S4: Calculation of system efficiency corresponding to the speed point: Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 Any one of them, the following is the speed point Spd in the kth program execution cycle i The corresponding system efficiency is calculated; (1) According to the motor speed Spd i and torque T i (k) Check the motor efficiency map to get the motor efficiency Eff mi (k); (2) According to the motor speed Spd i , pump load pressure P1(k) and pump displacement value Dpl 1i (k) Check the pump efficiency map to get the pump efficiency value Eff p1i (k), according to the motor speed Spdi , Pump 2 load pressure P2(k) and Pump 2 displacement value Dpl 2i (k) Check the pump 2 efficiency map to get the pump 2 efficiency value Eff p2i (k), and then calculate the overall efficiency of pump 1 and pump 2, and the motor efficiency Eff mi (k) multiplied to get the system comprehensive efficiency Eff i (k).

[0039] .

[0040] S5: Optimal solution screening: (1) The motor speed is traversed to the values ​​Spd1, Spd2, ... Spd 100 The efficiencies calculated in the above are sorted from high to low; (2) Set the motor torque and pump displacement allowable step value ∆T according to the motor and pump characteristics Lim ,∆Dpl Lim , as the judgment condition for the optimal solution screening, to ensure that the motor torque and pump displacement values ​​screened out in each program cycle are within the range that the system response capability can satisfy; First, compare the torque change corresponding to the highest efficiency, the displacement change of pump one and pump two, and the allowable step value. If they are within the step value range, the torque and displacement corresponding to the optimal solution are taken as the target value. Otherwise, sort them according to the efficiency in turn to determine whether the torque and displacement corresponding to the next efficiency value can meet the step value requirements, until the optimal efficiency value that meets the step value requirements is screened out, and the torque and displacement corresponding to this efficiency are taken as the target value.

[0041] Embodiment 4 is based on the same inventive concept as other embodiments. This embodiment introduces a computer-readable storage medium storing one or more programs, wherein the one or more programs include instructions, and when the instructions are executed by a computing device, the computing device executes the method described in Embodiment 1.

[0042] Embodiment 5, a computer device, comprising: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing the method described in Example 1.

[0043] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0044] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0045] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0046] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0047] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A load-adaptive coordinated control method for electric-driven double pumps, characterized in that: include: Obtaining a target flow rate of pump one and a target flow rate of pump two in a double pump; Determine the motor speed range according to the target flow rate of pump one and the target flow rate of pump two, and divide a plurality of speed operating points according to the motor speed range; Calculate the steady-state torque corresponding to each speed operating point based on the motor speed at each speed operating point; The steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and the dynamic adjustment torque is obtained by closed-loop calculation as the motor target torque corresponding to the current speed operating point; Based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point, the motor efficiency value is obtained; based on the motor speed at the current speed operating point and the obtained pump one load pressure and pump one displacement values, the pump one efficiency value is determined; based on the motor speed at the current speed operating point and the obtained pump two load pressure and pump two displacement values, the pump two efficiency value is determined; based on the motor efficiency value, pump one efficiency value and pump two efficiency value, the comprehensive efficiency value is calculated; The comprehensive efficiency values ​​corresponding to the multiple speed operating points are sorted in order from high to low, and the optimal solutions are screened starting from the motor target torque and pump one displacement value and pump two displacement value corresponding to the highest comprehensive efficiency value. When the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value meet the preset step value range, the motor target torque and pump one displacement value and pump two displacement value of the comprehensive efficiency value are output as the final target value for execution.

2. The load-adaptive coordinated control system of the electric drive double pump according to claim 1 is characterized in that: The step of obtaining a target flow rate of pump one and a target flow rate of pump two in the double pump comprises: When the change ∆Q1 between the current flow request of pump one and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump two and the flow request at the previous moment exceeds the set threshold, the target flow Q1 of pump one and the target flow Q2 of pump two are updated to the current flow request of the corresponding pump, otherwise the target flow Q1 of pump one and the target flow Q2 of pump two are the flow request of the corresponding pump at the previous moment.

3. The load-adaptive coordinated control system of the electric drive double pump according to claim 2 is characterized in that: The motor speed range is determined according to the target flow rate of the pump 1 and the target flow rate of the pump 2, and a plurality of speed operating points are divided according to the motor speed range, including: According to the target flow rate Q1 of pump one, the target flow rate Q2 of pump two and the maximum speed Spd of the motor obtained max , the minimum and maximum displacement values ​​of pump 1 and pump 2 are Dpl min 、Dpl max Screening to obtain the motor speed range that meets the flow requirements [Spd low Sd up ], Spd low =max(Q1 / Dpl max ,Q2 / Dpl max ); Spd up =min(min(Q1 / Dpl min ,Q2 / Dpl min ),Spd max ); Where, Spd low The minimum speed value to meet the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2, Spd up The maximum speed value that satisfies both the target flow rate Q1 of pump one and the target flow rate Q2 of pump two; In the motor speed range [Spd low Sd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N ,Spd i Represents the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, N is the total number of speed operating points.

4. The load-adaptive coordinated control system of the electric-driven double pump according to claim 3 is characterized in that: The calculation formula of the steady-state torque corresponding to the speed operating point is: T si (k)= P1(k) * Dpl 1i (k)+ P2(k) * Dpl 2i (to); Where, T si (k) is the steady-state torque corresponding to the i-th speed operating point of the current execution cycle k, P1(k) is the load pressure of pump 1 in the current execution cycle k, P2(k) is the load pressure of pump 2 in the current execution cycle k, Dpl 1i (k) is the pump displacement value of the i-th speed operating point in the current execution cycle k, Dpl 2i (k) is the value of the pump displacement at the i-th speed operating point in the current execution cycle k.

5. The load-adaptive coordinated control system of the electric-driven double pump according to claim 4 is characterized in that: The method of superimposing the speed difference on the steady-state torque corresponding to the current speed operating point and performing closed-loop calculation to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point includes: According to the speed Spd of the current i-th speed operating point i The actual motor speed Spd collected real (k) Calculate the speed difference ∆Spd(k); A PID algorithm is used to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), and in the process of using the PID algorithm to calculate the motor regulating torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into several intervals in combination with the speed difference ∆Spd(k), and each interval corresponds to a set of proportional parameters, integral parameters, and differential parameters.

6. The load-adaptive coordinated control system of the electric-driven double pump according to claim 5 is characterized in that: The calculation formula of the motor target torque is: T i (k)=T di (k)+ T si (k); Where, T i (k) is the speed Spd of the i-th speed operating point in the current execution cycle k i The corresponding motor target torque, T d (k) is the adjustment torque requirement corresponding to the i-th speed operating point of the current execution cycle k; ； Where P is the proportional parameter in the PID algorithm, I is the integral parameter I in the PID algorithm, D is the differential parameter in the PID algorithm, ∆Spd(k) and ∆Spd(k-1) are the differences between the motor target speed and the actual speed in the kth and k-1th execution cycles respectively, and ∆Spd(j) is the speed deviation of a cycle before the kth program cycle, where j ranges from 0, 1, 2, …, k.

7. The load-adaptive coordinated control system of the electric-driven double pump according to claim 6 is characterized in that: The calculation formula of the comprehensive efficiency value is: ； Where Eff i (k) is the comprehensive efficiency value of the i-th speed operating point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed operating point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed operating point in the current execution cycle k, Eff p1i (k) is the pump efficiency value of the i-th speed working point in the current execution cycle k, Eff p2i (k) is the efficiency value of pump 2 at the i-th speed operating point in the current execution cycle k, Eff mi (k) is the motor efficiency value of the i-th speed operating point in the current execution cycle k.

8. A system for executing the load adaptive coordinated control method of an electric-driven double pump according to any one of claims 1 to 7, characterized in that: It includes a hydraulic controller, an electric drive assembly, a pump 1, a pump 2, a first pressure sensor, a second pressure sensor, and a coordinated controller; The hydraulic controller outputs the flow requirements of pump 1 and pump 2 to the collaborative controller according to the action requirements of the hydraulic actuator at the rear end of the excavator; The electric drive assembly is a component assembly integrating a motor and a motor controller, and is used as a power source for a double pump, wherein the double pump comprises a pump 1 and a pump 2, and the rotors of the pump 1 and the pump 2 are driven to rotate synchronously by the output shaft of the motor; The first pressure sensor and the second pressure sensor respectively collect the load pressure of the output port of the pump 1 and the load pressure of the output port of the pump 2; The collaborative controller receives the flow demand of pump one and the flow demand of pump two and the actual speed of the motor, and reads the load pressure of pump one and pump two collected by the pressure sensor, calculates and outputs the motor torque command and the displacement command of pump one and pump two, which are the optimal efficiency values ​​of the comprehensive efficiency of pump one working efficiency, pump two working efficiency and motor working efficiency, and performs collaborative control of the electric-driven dual pumps through the motor torque command and the displacement command of pump one and pump two.

9. A computer-readable storage medium storing one or more programs, characterized in that: The one or more programs include instructions which, when executed by a computing device, cause the computing device to perform the method of any one of claims 1 to 7.

10. A computer device, characterized in that: include, One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for executing any of the methods described in claims 1 to 7.

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