A method and system for load adaptive cooperative control of an electrically driven double pump

Abstract

The application discloses a kind of electric drive duplex pump load adaptive cooperative control method and system, obtain the target flow of pump one in duplex pump and the target flow of pump two;Divide multiple speed working points;The steady-state torque corresponding to speed working point is calculated;The motor target torque corresponding to speed working point is calculated;Comprehensive efficiency value is calculated;Comprehensive efficiency value is sequentially sorted from high to low, from the motor target torque and pump one displacement value, pump two displacement value corresponding to the highest comprehensive efficiency value, sequentially optimal solution screening is carried out, when meeting the preset step value range, the motor target torque and pump one displacement value, pump two displacement value of this comprehensive efficiency value are output as final executed target value.The advantages are: through comprehensive efficiency value and step value determination condition optimal solution screening, higher system efficiency is obtained on the basis of meeting system flow demand;Motor target torque can reduce the sudden change of motor speed caused by load change, improve speed response and stability.

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 most popular new energy source currently, new energy is gradually becoming more prominent in its application and value in the field of construction machinery. It provides more efficient, environmentally friendly, and energy-saving solutions for engineering construction, and promotes the electrification and intelligent development of construction machinery. Excavators play a vital role in engineering construction and maintain a growth momentum, and the electrification of excavators continues to accelerate. Currently, the most common configuration used by electric excavators is the oil-to-electric conversion method, that is, the electric motor replaces the engine as the power source, and the traditional hydraulic system remains unchanged. Although the overall efficiency of the machine has been improved compared to the fuel-powered model, the overall energy efficiency is low, the cost is high, and the competitiveness is weaker than that of traditional models. An upgrade of the technical architecture is urgently needed.

[0003] The electrification of excavators has promoted the application of electric 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 and variable displacement, which has broad application scenarios.

[0004] Existing technologies for electrifying excavator hydraulic drive systems have enabled the application of motor-driven pumps and control methods. However, these systems only control a single variable, either speed or displacement, without adopting a dual-variable control strategy for both flow and displacement. Consequently, overall system efficiency remains suboptimal. Furthermore, motor speed regulation is not factored into load pressure, leaving room for improvement in system responsiveness. 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 for an electric-driven double pump, comprising:

[0008] Obtaining a target flow rate of pump one and a target flow rate of pump two in a duplex pump;

[0009] Determine a motor speed range according to the target flow rate of the first pump and the target flow rate of the second pump, and divide the motor speed range into a plurality of speed operating points;

[0010] Calculate the steady-state torque corresponding to each speed operating point based on the motor speed at each speed operating point;

[0011] The steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and a closed-loop calculation is performed to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point;

[0012] Obtain a motor efficiency value based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point; determine a pump 1 efficiency value based on the motor speed at the current speed operating point and the obtained pump 1 load pressure and pump 1 displacement values; determine a pump 2 efficiency value based on the motor speed at the current speed operating point and the obtained pump 2 load pressure and pump 2 displacement values; calculate a comprehensive efficiency value based on the motor efficiency value, the pump 1 efficiency value, and the pump 2 efficiency value;

[0013] 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 in order 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 to be executed.

[0014] Furthermore, obtaining the target flow rate of pump one and the target flow rate of pump two in the double pump includes:

[0015] When the change ∆Q1 between the current flow request of pump 1 and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump 2 and the flow request at the previous moment exceeds the set threshold, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to the current flow request of the corresponding pump. Otherwise, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to the flow request of the corresponding pump at the previous moment.

[0016] Furthermore, the motor speed range is determined according to the target flow of the pump 1 and the target flow of the pump 2, and a plurality of speed operating points are divided according to the motor speed range, including:

[0017] According to the target flow rate Q1 of pump 1, the target flow rate Q2 of pump 2 and the maximum speed Spd of the motor 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 Spd up ],

[0018] Spd low =max(Q1 / Dpl max, Q2 / Dpl max );

[0019] Spd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spd max );

[0020] 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 1 and the target flow rate Q2 of pump 2;

[0021] In the motor speed range [Spd low Spd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N , Spd i Indicates the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, and N is the total number of speed operating points.

[0022] Furthermore, the calculation formula for the steady-state torque corresponding to the speed operating point is:

[0023] T si (k) = P1(k) * Dpl 1i (k)+ P2(k) * Dpl 2i (k);

[0024] Where, T si (k) is the steady-state torque corresponding to the i-th speed operating point in 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.

[0025] Furthermore, 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:

[0026] According to the current speed Spd of the i-th speed operating point i The actual motor speed Spd collected real (k) Calculate the speed difference ∆Spd(k);

[0027] A PID algorithm is used to calculate a motor regulation torque required to eliminate the speed difference ∆Spd(k). In the process of using the PID algorithm to calculate the motor regulation torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into a plurality of intervals based on the speed difference ∆Spd(k), and each interval corresponds to a set of proportional parameters, integral parameters, and differential parameters.

[0028] Furthermore, the calculation formula of the motor target torque is:

[0029] T i (k)=T di (k)+ T si (k);

[0030] 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 in the current execution cycle k;

[0031] ;

[0032] Where P is the proportional parameter in the PID algorithm, I is the integral parameter I in the PID algorithm, and D is the differential parameter in the PID algorithm. ∆Spd(k) and ∆Spd(k-1) are the differences between the target and actual motor speeds for the kth and k-1th execution cycles, respectively. ∆Spd(j) is the speed deviation in a cycle before the kth program cycle, where j ranges from 0, 1, 2, …, k.

[0033] Furthermore, the calculation formula of the comprehensive efficiency value is:

[0034] ;

[0035] Where, Eff i (k) is the comprehensive efficiency value of the i-th speed working point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed working point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed working 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.

[0036] In a second aspect, the present invention discloses a load-adaptive coordinated control system for 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;

[0037] The hydraulic controller outputs the flow requirements of pump 1 and pump 2 to the collaborative controller based on the action requirements of the hydraulic actuator at the rear end of the excavator;

[0038] The electric drive assembly is a component assembly integrating a motor and a motor controller, and is used as a power source for a duplex pump. The duplex pump includes a first pump and a second pump, and the rotors of the first pump and the second pump are driven to rotate synchronously by the output shaft of the motor.

[0039] 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;

[0040] 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 instruction and the displacement instruction 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 drive double pumps through the motor torque instruction and the displacement instruction of pump one and pump two.

[0041] 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 that, when executed by a computing device, cause the computing device to perform the method of the first aspect.

[0042] In a fourth aspect, the present invention discloses a computer device, comprising:

[0043] 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.

[0044] The beneficial effects achieved by the present invention are:

[0045] By traversing the speed values, 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, 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. On the basis of meeting the system flow requirements, higher system efficiency is obtained.

[0046] The motor torque demand is the feedforward torque calculated by taking the load pressure and displacement values ​​of pumps one and two, superimposed on the regulating torque calculated by the closed-loop speed deviation. The closed-loop control parameters are adjusted in real time taking into account the speed difference, thereby reducing the sudden change in motor speed caused by load changes and improving speed responsiveness and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a diagram of the structure of the electric drive double pump load adaptive collaborative control system;

[0048] Figure 2 It is a flow chart of the load adaptive collaborative control method of electric drive dual pumps. DETAILED DESCRIPTION

[0049] 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 solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] 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 orientations or positional relationships based on the orientations 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", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. 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.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0052] Example 1: This example introduces a load-adaptive coordinated control method for an electric-driven double pump, including:

[0053] Obtaining a target flow rate of pump one and a target flow rate of pump two in a duplex pump;

[0054] Determine a motor speed range according to the target flow rate of the first pump and the target flow rate of the second pump, and divide the motor speed range into a plurality of speed operating points;

[0055] Calculate the steady-state torque corresponding to each speed operating point based on the motor speed at each speed operating point;

[0056] The steady-state torque corresponding to the current speed operating point is superimposed on the speed difference, and a closed-loop calculation is performed to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point;

[0057] Obtain a motor efficiency value based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point; determine a pump 1 efficiency value based on the motor speed at the current speed operating point and the obtained pump 1 load pressure and pump 1 displacement values; determine a pump 2 efficiency value based on the motor speed at the current speed operating point and the obtained pump 2 load pressure and pump 2 displacement values; calculate a comprehensive efficiency value based on the motor efficiency value, the pump 1 efficiency value, and the pump 2 efficiency value;

[0058] 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 in order 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 to be executed.

[0059] The step of obtaining the target flow rate of pump one and the target flow rate of pump two in the duplex pump comprises:

[0060] When the change ∆Q1 between the current flow request of pump 1 and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump 2 and the flow request at the previous moment exceeds the set threshold, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to the current flow request of the corresponding pump. Otherwise, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to the flow request of the corresponding pump at the previous moment.

[0061] 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:

[0062] According to the target flow rate Q1 of pump 1, the target flow rate Q2 of pump 2 and the maximum speed Spd of the motor 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 Spd up ],

[0063] Spd low =max(Q1 / Dpl max , Q2 / Dpl max );

[0064] Spd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spd max );

[0065] 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 1 and the target flow rate Q2 of pump 2;

[0066] In the motor speed range [Spd low Spd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N , Spd i Indicates the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, and N is the total number of speed operating points.

[0067] The calculation formula of the steady-state torque corresponding to the speed operating point is:

[0068] T si (k) = P1(k) * Dpl 1i (k)+ P2(k) * Dpl 2i (k);

[0069] Where, T si (k) is the steady-state torque corresponding to the i-th speed operating point in 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.

[0070] 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:

[0071] According to the current speed Spd of the i-th speed operating point iThe actual motor speed Spd collected real (k) Calculate the speed difference ∆Spd(k);

[0072] A PID algorithm is used to calculate a motor regulation torque required to eliminate the speed difference ∆Spd(k). In the process of using the PID algorithm to calculate the motor regulation torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into a plurality of intervals based on the speed difference ∆Spd(k), and each interval corresponds to a set of proportional parameters, integral parameters, and differential parameters.

[0073] The calculation formula of the motor target torque is:

[0074] T i (k)=T di (k)+ T si (k);

[0075] 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 in the current execution cycle k;

[0076] ;

[0077] Where P is the proportional parameter in the PID algorithm, I is the integral parameter I in the PID algorithm, and D is the differential parameter in the PID algorithm. ∆Spd(k) and ∆Spd(k-1) are the differences between the target and actual motor speeds for the kth and k-1th execution cycles, respectively. ∆Spd(j) is the speed deviation in a cycle before the kth program cycle, where j ranges from 0, 1, 2, …, k.

[0078] The calculation formula of the comprehensive efficiency value is:

[0079] ;

[0080] Where, Eff i (k) is the comprehensive efficiency value of the i-th speed working point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed working point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed working 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.

[0081] 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 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; 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 according to 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.

[0082] Example 2: This example introduces a load-adaptive coordinated control system for electric drive double pumps. The system is composed of Figure 1 As shown, the system includes a hydraulic controller, an electric drive assembly, pump 1, pump 2, a first pressure sensor, a second pressure sensor, and a coordinated controller. The hydraulic controller outputs the flow requirements of pumps 1 and 2 to the coordinated controller based on 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 motor controller and serves as the power source for the duplex pumps. Pumps 1 and 2 together form a duplex pump, with the rotors of the two pumps driven by the motor output shaft to rotate synchronously. The first and second pressure sensors respectively collect the load pressures at the output ports of pumps 1 and 2. The coordinated controller receives the flow requirements of pumps 1 and 2 and the actual speed of the motors, and reads the load pressures of pumps 1 and 2 collected by the pressure sensors. Based on these signals, it calculates and outputs motor torque commands and displacement commands for pumps 1 and 2, thus achieving coordinated control of the electric drive duplex pump system.

[0083] Example 3 is based on the same inventive concept as Example 1. This example introduces a coordinated control method for load adaptation of electric drive double pumps, which is applied to the coordinated control system for load adaptation of electric drive double pumps in Example 2. The control process is as follows: Figure 2 As shown, the control of the electric drive double pump can be divided into five steps: selecting the working speed point, calculating the steady-state torque corresponding to the speed point, calculating the target torque corresponding to the speed point, calculating the system efficiency corresponding to the speed point, and screening the optimal solution, as shown below:

[0084] S1: Working speed selection point

[0085] (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.

[0086] (2) According to the target flow rate Q1, Q2, the maximum motor speed Spdmax , 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 Spd up ].

[0087] Spd low =max(Q1 / Dpl max , Q2 / Dpl max );

[0088] Spd up =min(min(Q1 / Dpl min , Q2 / Dpl min ), Spd max );

[0089] (3) In the speed range [Spd low Spd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd 100 .

[0090] S2: Calculation of steady-state torque corresponding to the speed point

[0091] Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 For any one of the following, the speed point Spd in the kth program execution cycle is i The corresponding steady-state torque is calculated.

[0092] (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 value of the speed is Spd i Calculate the corresponding pump 1 and pump 2 displacement values ​​Dpl 1i (k), Dpl 2i (k);

[0093] Dpl 1i (k) = Q1(k) / Spd i (k);

[0094] Dpl 2i (k) = Q2(k) / Spd i (k);

[0095] (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);

[0096] T si (k) = P1(k) * Dpl 1i (k)+ P2(k) * Dpl 2i (k);

[0097] S3: Calculation of target torque corresponding to the speed point

[0098] Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 For any one of the following, the speed point Spd in the kth program execution cycle is i The corresponding target torque is calculated;

[0099] (31) Take the value Spd according to the current speed i and actual speed Spd real (k) Calculate the speed difference ∆Spd(k);

[0100] (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 four intervals based on 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 improving the torque adjustment control accuracy. The specific calculation method is as follows:

[0101] ;

[0102] Where k is the control system program execution cycle count, T d (k) is the regulated torque demand for the kth program execution cycle; ∆Spd(k) and ∆Spd(k-1) are the differences between the target and actual motor speeds for the kth and k-1th program execution cycles, respectively. The selection of P, I, and D parameters typically requires calibration based on actual vehicle testing. Table 1 provides a set of reference values ​​used during implementation.

[0103] Table 1

[0104] (33) The current speed point Spd at the final k moment i The corresponding target torque T i (k) is:

[0105] T i (k)=T di (k)+ T si (k);

[0106] 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 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 taken into account, which can improve the speed control accuracy and response speed.

[0107] S4: Calculation of system efficiency corresponding to the speed point:

[0108] Assume Spd i The motor speed traverses the values ​​Spd1, Spd2...Spd 100 For any one of the following, the speed point Spd in the kth program execution cycle is i Calculate the corresponding system efficiency;

[0109] (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);

[0110] (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 Spd i , 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 overall system efficiency Eff i (k).

[0111] .

[0112] S5: Optimal solution screening:

[0113] (1) The motor speed is traversed to the values ​​Spd1, Spd2...Spd 100 The efficiencies calculated in the above example are sorted from high to low;

[0114] (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 screening the optimal solution, it ensures that the motor torque and pump displacement values ​​screened out in each program cycle are within the range that can be satisfied by the system response capability;

[0115] 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 will be executed as the target value. Otherwise, sort them in order according to the efficiency, and judge whether the torque and displacement values ​​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 will be executed as the target value.

[0116] Example 4 is based on the same inventive concept as other examples. This example introduces a computer-readable storage medium that stores one or more programs, wherein the one or more programs include instructions that, when executed by a computing device, enable the computing device to execute the method described in Example 1.

[0117] Embodiment 5, a computer device, comprising:

[0118] 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.

[0119] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. 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 magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0120] 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 flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, 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 flowcharts and / or block diagrams. 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.

[0121] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0122] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0123] 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 drive double pumps, characterized in that: include: Obtaining a target flow rate of pump one and a target flow rate of pump two in a duplex pump; Determine a motor speed range according to the target flow rate of the first pump and the target flow rate of the second pump, and divide the motor speed range into a plurality of speed operating points; 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 a closed-loop calculation is performed to obtain the dynamic adjustment torque as the motor target torque corresponding to the current speed operating point; Obtain a motor efficiency value based on the motor speed at the current speed operating point and the motor target torque corresponding to the current speed operating point; determine a pump 1 efficiency value based on the motor speed at the current speed operating point and the obtained pump 1 load pressure and pump 1 displacement values; determine a pump 2 efficiency value based on the motor speed at the current speed operating point and the obtained pump 2 load pressure and pump 2 displacement values; calculate a comprehensive efficiency value based on the motor efficiency value, the pump 1 efficiency value, and the pump 2 efficiency value; 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 in order 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 to be executed.

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 the target flow rate of pump one and the target flow rate of pump two in the duplex pump comprises: When the change ∆Q1 between the current flow request of pump 1 and the flow request at the previous moment or the change ∆Q2 between the current flow request of pump 2 and the flow request at the previous moment exceeds the set threshold, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to the current flow request of the corresponding pump. Otherwise, the target flow rate Q1 of pump 1 and the target flow rate Q2 of pump 2 are updated to 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 1, the target flow rate Q2 of pump 2 and the maximum speed Spd of the motor 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 Spd 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 1 and the target flow rate Q2 of pump 2; In the motor speed range [Spd low Spd up ] Set the speed working point at equal intervals: Spd1, Spd2...Spd N , Spd i Indicates the motor speed corresponding to the i-th speed operating point, i=1,2,…,N, and N is the total number of speed operating points.

4. The load-adaptive coordinated control system of the electric drive 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 in 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 drive 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 current speed Spd of the 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 a motor regulation torque required to eliminate the speed difference ∆Spd(k). In the process of using the PID algorithm to calculate the motor regulation torque required to eliminate the speed difference ∆Spd(k), the PID parameters are divided into a plurality of intervals based on 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 drive 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 di (k) is the adjustment torque requirement corresponding to the i-th speed operating point in 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, and D is the differential parameter in the PID algorithm. ∆Spd(k) and ∆Spd(k-1) are the differences between the target and actual motor speeds for the kth and k-1th execution cycles, respectively. ∆Spd(j) is the speed deviation in 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 drive 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 working point in the current execution cycle k, Q1(k) is the target flow rate of pump 1 at the i-th speed working point in the current execution cycle k, Q2(k) is the target flow rate of pump 2 at the i-th speed working 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: Includes a hydraulic controller, an electric drive assembly, a pump 1, a pump 2, a first pressure sensor, a second pressure sensor, and a collaborative controller; The hydraulic controller outputs the flow requirements of pump 1 and pump 2 to the collaborative controller based on 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 duplex pump. The duplex pump includes a first pump and a second pump, and the rotors of the first pump and the second pump 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 instruction and the displacement instruction 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 drive double pumps through the motor torque instruction and the displacement instruction 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 that, 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 the method of any one of claims 1 to 7.

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