Vibration suppression control method of hydraulic drive hydrogen compressor and hydraulic system

Abstract

The invention discloses a vibration suppression control method of a hydraulic drive hydrogen compressor and a hydraulic system, and belongs to the technical field of hydraulic transmission. According to the control method, the rotating speed of a servo motor and the displacement of a two-way variable pump are controlled in a coordinated mode in real time, and system resonance is suppressed from the source; the core of the method is that a genetic algorithm is adopted to carry out multi-target dynamic optimization on the control precision and operation efficiency of a servo motor and a two-way variable pump, when a load or flow changes, a new optimal rotating speed-displacement combination point can be quickly found, the system is adjusted to the point to work, it is guaranteed that the system can efficiently and stably operate under all working conditions, and the system is stable in operation. The energy utilization efficiency is improved; according to the hydraulic system, the hot oil shuttle valve is adopted for replacing high-temperature oil liquid, and heating of the system is effectively reduced. Active vibration suppression and efficient heat management are integrated, and the comprehensive performance of the liquid-driven hydrogen compressor is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic transmission technology, and in particular to a vibration suppression control method and hydraulic system for a liquid-driven hydrogen compressor. Background Technology

[0002] Hydrogen compressors are key equipment in the hydrogen energy industry chain, undertaking the core functions of hydrogen pressurization, storage, and transportation. Hydraulically driven hydrogen compressors (referred to as liquid-driven hydrogen compressors) achieve compression by changing the gas volume through hydraulic pistons. They have advantages such as high output pressure and a wide flow adjustment range, and have become the mainstream technology in hydrogen refueling stations and other scenarios.

[0003] Currently, most liquid-driven hydrogen compressors employ a hydraulic drive system based on fixed-parameter PID control. Gas compression is achieved by controlling the reciprocating motion of the hydraulic cylinder through a preset program. The system typically includes a hydraulic power unit, a compression cylinder with direct gas-liquid contact, and a set of control valves. Its operation relies on a pre-set pressure-flow curve for control.

[0004] Existing technologies suffer from three prominent drawbacks: First, the dynamic instability of the gas-liquid coupling interface can trigger severe water hammer effects, generating high-frequency pressure shocks; second, the hydraulic system lacks adaptive adjustment capabilities during wide-range operating condition switching, leading to transient response misalignment; and third, the control strategy under sudden load changes is simplistic and cannot achieve dynamic compensation. These problems collectively result in strong vibrations and noise in the system, accelerating mechanical fatigue damage and seal failure, significantly increasing energy consumption, and severely restricting the reliability, service life, and operational economy of the equipment. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a vibration suppression control method and hydraulic system for a liquid-driven hydrogen compressor. By analyzing the vibration mechanism of the liquid-driven hydrogen compressor, establishing a model of the operating efficiency and a mathematical model of the control accuracy of the liquid-driven hydrogen compressor, and optimizing through an optimization algorithm, the speed of the servo motor and the displacement of the bidirectional variable pump are coordinated and controlled. Under the premise of ensuring operating efficiency and performance, the control accuracy of the liquid-driven hydrogen compressor is improved, which can effectively suppress system vibration and shock, improve the high reliability of the liquid-driven hydrogen compressor, and extend the service life of the liquid-driven hydrogen compressor.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] A vibration suppression control method for a liquid-driven hydrogen compressor includes the following steps:

[0008] S1. Real-time monitoring of the system pressure, flow rate, current servo motor speed, and bidirectional variable pump displacement of the hydraulic system of the liquid-driven hydrogen compressor.

[0009] S2, the natural frequency of the acquisition system, the resonant frequency of the calculation system, and the instantaneous excitation frequency generated by the current operating conditions;

[0010] S3. Analyze the system frequency domain to determine the feasible operating range of the servo motor speed and bidirectional variable pump displacement outside the resonant frequency range.

[0011] S4. Using the feasible working domain as a constraint, establish a multi-objective optimization model that takes into account both system operating efficiency and system control accuracy.

[0012] S5. Within the feasible working domain, generate an initial population for the genetic algorithm;

[0013] S6. Using the servo motor speed as the optimization variable, and based on the multi-objective optimization model, perform iterative optimization calculations using a genetic algorithm.

[0014] S7. From the final population after the iterative optimization, select the individual with the highest fitness as the optimal servo motor speed output.

[0015] S8. Based on the optimal servo motor speed, calculate the optimal bidirectional variable pump displacement to match it, thereby determining the optimal speed-displacement combination operating point of the system; adjust the servo motor and bidirectional variable pump to work together according to the optimal speed-displacement combination operating point; then, return to step S1 to realize closed-loop vibration suppression control.

[0016] A further improvement to the technical solution of the present invention lies in: in S2, the resonant frequency of the system... The calculation formula is:

[0017]

[0018] In the formula, This is the system's natural frequency; Let be the damping ratio of the system.

[0019] A further improvement to the technical solution of the present invention is that, in S3, the feasible working domain derivation process of the servo motor speed is as follows:

[0020] To avoid system resonance, the following conditions must be met:

[0021]

[0022] In the formula, This is the system's natural frequency; This is the resonant frequency of the system; Where z is the instantaneous excitation frequency, z is the number of plungers in the bidirectional variable pump, and n is the servo motor speed;

[0023] Based on this, the feasible operating domain of the servo motor speed is calculated:

[0024]

[0025]

[0026]

[0027] The feasible operating range of the servo motor speed is as follows:

[0028] and ;

[0029] In the formula, The feasible operating range for servo motor speed. This is the minimum speed of the servo motor. This represents the maximum speed of the servo motor.

[0030] A further improvement to the technical solution of this invention lies in the following: In S3, the feasible working domain expression for the displacement of the bidirectional variable pump is:

[0031]

[0032] In the formula, V represents the real-time displacement of the bidirectional variable pump. This is the maximum displacement of the bidirectional variable pump.

[0033] A further improvement to the technical solution of this invention lies in the following: In S4, the system operating efficiency model expression is:

[0034]

[0035]

[0036]

[0037]

[0038] In the formula, For the system operating efficiency model, This is a mechanical efficiency model for a bidirectional variable pump. This is a volumetric efficiency model for a two-way variable pump. This is the efficiency model for the servo motor, where μ is the dynamic viscosity of the oil, p is the outlet pressure of the bidirectional variable pump, and n is the current speed of the servo motor. This is the laminar flow drag coefficient. This is the mechanical resistance coefficient. Let the torque loss constant be... V represents the maximum displacement of the bidirectional variable pump, and V represents the displacement of the bidirectional variable pump. The laminar leakage coefficient is... ω represents the output torque of the servo motor, and ω represents the output speed of the servo motor. For the mechanical losses of the servo motor, For the iron loss of the servo motor, For servo motor copper losses, This refers to the losses incurred by the servo motor driver.

[0039] A further improvement to the technical solution of this invention lies in the following: In S4, the mathematical model expression for the system control accuracy is:

[0040]

[0041] In the formula: , where is the stiffness constant of the hydraulic system; , is the volume constant of the bidirectional variable pump; , is a fixed volume constant; , where is the total mass constant; P(n) is the accuracy performance index; This refers to the effective bulk modulus of the oil. The effective area of ​​the hydraulic cylinder piston; The fixed volume of the hydraulic system includes the oil volume of the pipelines and valve bodies; k is the volume ratio coefficient. The equivalent total mass of the hydraulic system; This refers to the rated speed of the servo motor. This is the bandwidth gain coefficient; This is the saturation effect coefficient; This represents the high-speed degradation coefficient.

[0042] A further improvement to the technical solution of this invention lies in that, in S4, the expression of the multi-objective optimization model is:

[0043]

[0044] In the formula, h represents the multi-objective optimization model; For system operating efficiency model; A mathematical model for system control accuracy.

[0045] A hydraulic system for a liquid-driven hydrogen compressor includes a servo motor, a bidirectional variable pump, a hydraulic cylinder, an oil tank, and a first oil circuit and a second oil circuit connecting the bidirectional variable pump and the hydraulic cylinder. The servo motor drives the bidirectional variable pump. The first port of the bidirectional variable pump is connected to one side of the hydraulic cylinder through the first oil circuit, and the second port of the bidirectional variable pump is connected to the other side of the hydraulic cylinder through the second oil circuit.

[0046] It also includes a hot oil shuttle valve, a first relief valve, a second relief valve, and a third relief valve;

[0047] The hot oil shuttle valve has a first oil port, a second oil port and a third oil port, wherein the first oil port is connected to the first oil circuit, the second oil port is connected to the second oil circuit, and the third oil port is connected to the oil inlet of the third overflow valve.

[0048] The inlet of the first relief valve is connected to the first oil circuit, the inlet of the second relief valve is connected to the second oil circuit, and the outlets of both the first and second relief valves are connected to the system's drain line; the outlet of the third relief valve is connected to the system's return line.

[0049] A further improvement of the technical solution of the present invention is that the hot oil shuttle valve is configured such that the oil at the higher pressure end is always directed to the third oil port of the hot oil shuttle valve in the first oil port and the second oil port of the hot oil shuttle valve.

[0050] A further improvement of the technical solution of the present invention is that: a cooler and a filter are sequentially arranged along the oil flow direction on the return oil pipeline; the oil outlet of the third overflow valve is connected to the return oil pipeline, so that the oil discharged from the hot oil shuttle valve can flow through the cooler and the filter in sequence and then return to the oil tank.

[0051] The technological advancements achieved by this invention due to the adoption of the above technical solutions are as follows:

[0052] 1. The present invention provides a vibration suppression control method for a liquid-driven hydrogen compressor, which reduces system resonance at the source by coordinating the control of the servo motor speed and the bidirectional variable pump displacement, thereby improving energy utilization efficiency compared to passive vibration suppression methods.

[0053] 2. The present invention provides a vibration suppression control method for a liquid-driven hydrogen compressor. It uses a genetic algorithm to perform multi-objective dynamic optimization of the control accuracy and working efficiency of the servo motor and the bidirectional variable pump. When the load or flow rate changes, it can quickly perform optimization under the new working conditions to obtain a new high-efficiency and high-control-accuracy speed-displacement combination point, and adjust the servo motor and the bidirectional variable pump to work at the speed-displacement combination point.

[0054] 3. The hydraulic system for a liquid-driven hydrogen compressor provided by the present invention uses a hot oil shuttle valve to replace the high-temperature oil in the hydraulic system, thereby reducing the heat generation problem of the hydraulic system while ensuring normal operation. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0056] Figure 1 This is a flowchart of a vibration suppression control method for a liquid-driven hydrogen compressor provided in an embodiment of the present invention;

[0057] Figure 2 This is a schematic diagram of the hydraulic principle of a liquid-driven hydrogen compressor hydraulic system provided in an embodiment of the present invention;

[0058] The components include: 1. Servo motor; 2. Bidirectional variable pump; 2.1. First oil port of the bidirectional variable pump; 2.2. Second oil port of the bidirectional variable pump; 2.3. Third oil port of the bidirectional variable pump; 3. Coupling; 4.1. First check valve; 4.2. Second check valve; 5.1. First relief valve; 5.2. Second relief valve; 5.3. Third relief valve; 5.4. Fourth relief valve; 6. Hot oil shuttle valve; 6.1. First oil port of the hot oil shuttle valve; 6.2. Second oil port of the hot oil shuttle valve; 6.3. Third oil port of the hot oil shuttle valve; 7. Flow meter. ; 8. Valve block; 9. Hydraulic cylinder; 10.1. First pressure relay; 10.2. Second pressure relay; 10.3. Third pressure relay; 11. Temperature sensor; 12. Three-phase asynchronous motor; 13. Unidirectional variable pump; 14. Accumulator; 15. Cooler; 16. Filter; 17. First channel; 18. Second channel; 19. First oil circuit; 20. Second oil circuit; 21. Drain line; 22. Oil tank; 23. Return line; 24. Controller; 25. Drain channel; 26. Leakage channel. Detailed Implementation

[0059] It should be noted that the terms "comprising" and "having" and any variations thereof in the specification, claims and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments:

[0063] like Figure 1 As shown, a vibration suppression control method for a liquid-driven hydrogen compressor includes the following steps:

[0064] S1. Real-time monitoring of the system pressure, flow rate, current servo motor speed, and bidirectional variable pump displacement of the hydraulic system of the liquid-driven hydrogen compressor.

[0065] S2, the natural frequency of the acquisition system, the resonant frequency of the calculation system, and the instantaneous excitation frequency generated by the current operating conditions;

[0066] The resonant frequency of the system The calculation formula is:

[0067]

[0068] In the formula, This is the system's natural frequency; Let be the damping ratio of the system.

[0069] S3. Analyze the system frequency domain to determine the feasible operating range of the servo motor speed and bidirectional variable pump displacement outside the resonant frequency range.

[0070] The derivation process of the feasible operating domain of the servo motor speed is as follows:

[0071] To avoid system resonance, the following conditions must be met:

[0072]

[0073] In the formula, This is the system's natural frequency; This is the resonant frequency of the system; For instantaneous excitation frequency,

[0074] z represents the number of plungers in the bidirectional variable pump, and n represents the speed of the servo motor.

[0075] Based on this, the feasible operating domain for calculating the servo motor speed is:

[0076]

[0077]

[0078]

[0079] The feasible operating range for the servo motor speed is as follows:

[0080] and ;

[0081] In the formula, The feasible operating range for servo motor speed. This is the minimum speed of the servo motor. This represents the maximum speed of the servo motor.

[0082] The feasible working domain expression for the displacement of a bidirectional variable pump is:

[0083]

[0084] In the formula, V represents the real-time displacement of the bidirectional variable pump. This is the maximum displacement of the bidirectional variable pump.

[0085] S4. Establish a multi-objective optimization model that takes into account both system operating efficiency and system control accuracy, using the feasible working domain as a constraint.

[0086] The system operating efficiency model expression is:

[0087]

[0088]

[0089]

[0090]

[0091] In the formula, For the system operating efficiency model, This is a mechanical efficiency model for a bidirectional variable pump. This is a volumetric efficiency model for a two-way variable pump. This is the efficiency model for the servo motor, where μ is the dynamic viscosity of the oil, p is the outlet pressure of the bidirectional variable pump, and n is the current speed of the servo motor. This is the laminar flow drag coefficient. This is the mechanical resistance coefficient. Let the torque loss constant be... V represents the maximum displacement of the bidirectional variable pump, and V represents the displacement of the bidirectional variable pump. The laminar leakage coefficient is... ω represents the output torque of the servo motor, and ω represents the output speed of the servo motor. For the mechanical losses of the servo motor, For the iron loss of the servo motor, For servo motor copper losses, This refers to the losses incurred by the servo motor driver.

[0092] The mathematical model expression for the system control accuracy is:

[0093]

[0094] In the formula: , where is the stiffness constant of the hydraulic system; , is the volume constant of the bidirectional variable pump; , is a fixed volume constant; , where is the total mass constant; P(n) is the accuracy performance index; This refers to the effective bulk modulus of the oil. The effective area of ​​the hydraulic cylinder piston; The fixed volume of the hydraulic system includes the oil volume of the pipelines and valve bodies; k is the volume ratio coefficient. The equivalent total mass of the hydraulic system; This refers to the rated speed of the servo motor. This is the bandwidth gain coefficient; This is the saturation effect coefficient; This represents the high-speed degradation coefficient.

[0095] The expression for the multi-objective optimization model is:

[0096]

[0097] In the formula, h represents the multi-objective optimization model; For system operating efficiency model; A mathematical model for system control accuracy.

[0098] S5. Within the feasible working domain, generate an initial population for the genetic algorithm;

[0099] S6. Using the servo motor speed as the optimization variable, iterative optimization calculations are performed using a genetic algorithm based on a multi-objective optimization model.

[0100] S7. From the final population after the iterative optimization, select the individual with the highest fitness as the optimal servo motor speed output.

[0101] In steps S5-S7, the specific implementation methods are as follows:

[0102] The servo motor speed n is set as the optimization variable. Floating-point encoding is used to generate the initial population for the genetic algorithm within the feasible solution space, and the fitness of each individual in the population is calculated. .

[0103] fitness The calculation formula is as follows:

[0104]

[0105] In the formula, α is a trade-off factor, and 0≤α≤1, which determines the degree of emphasis on control accuracy and operating efficiency. If control accuracy and operating efficiency are equally important, then α=0.5.

[0106] Subsequently, selection, crossover, and mutation operations are performed on the population to generate a new generation, and the fitness of each individual is re-evaluated. This evolutionary process is repeated until the optimal fitness of the population does not significantly improve over several generations, at which point the iteration terminates, and the individual with the highest fitness is selected as the optimal servo motor speed output.

[0107] S8. Based on the optimal servo motor speed, calculate the optimal bidirectional variable pump displacement to match it, thereby determining the optimal speed-displacement combination operating point of the system; adjust the servo motor and bidirectional variable pump to work together according to the optimal speed-displacement combination operating point; then return to step S1 to realize closed-loop vibration suppression control.

[0108] Based on the optimal servo motor speed, the calculation method for the optimal bidirectional variable pump displacement is as follows:

[0109]

[0110] In the formula, The optimal bidirectional variable pump displacement is given by Q, which represents the system flow rate (measured in S1). This is the optimal servo motor speed.

[0111] like Figure 2As shown, a hydraulic system for a liquid-driven hydrogen compressor includes a servo motor 1, a bidirectional variable pump 2 (with a first port 2.1, a second port 2.2, and a third port 2.3), a coupling 3, a first check valve 4.1, a second check valve 4.2, a first relief valve 5.1, a second relief valve 5.2, a third relief valve 5.3, a fourth relief valve 5.4, and a hot oil shuttle valve 6 (with a first port 6.1, a second port 6.2, and a third port 2.3). 6.3 (three oil ports), 7. Flow meter, 8. Valve block, 9. Hydraulic cylinder, 10.1 (first pressure relay), 10.2 (second pressure relay), 10.3 (third pressure relay), 11. Temperature sensor, 12. Three-phase asynchronous motor, 13. Unidirectional variable pump, 14. Accumulator, 15. Cooler, 16. Filter, 17. First channel, 18. Second channel, 19. First oil circuit, 20. Second oil circuit, 21. Drain pipe, 22. Oil tank, 23. Return pipe, 24. Controller, 25. Drain channel, 26. Leakage channel.

[0112] Both the servo motor 1 and the bidirectional variable pump 2 are connected to the controller 24;

[0113] The valve block 8 has a first channel 17, a second channel 18, an oil drain channel 25, and a leakage channel 26. The output shaft of the servo motor 1 is connected to the input shaft of the bidirectional variable pump 2 via a coupling 3. Each oil port of the bidirectional variable pump 2 is fitted against the wall of the valve block 8. The first oil port 2.1 of the bidirectional variable pump is connected to the hydraulic cylinder 9 via the first channel 17 and the first oil passage 19. The second oil port 2.2 of the bidirectional variable pump is connected to the hydraulic cylinder 9 via the second channel 18 and the second oil passage 20. The third oil port 2.3 of the bidirectional variable pump is connected to the leakage channel 26. The oil drain channel 25 is connected to the oil drain pipe 21. The leakage channel 26 is connected to the return oil pipe 23.

[0114] Accumulator 14 is connected to oil drain line 21;

[0115] The flow meter 7 is connected in series in the first channel 17, and the flow meter 7 is connected to the controller 24;

[0116] Temperature sensor 11 is installed on oil drain channel 25;

[0117] The three-phase asynchronous motor 12 is coaxially connected to the one-way variable pump 13;

[0118] The inlet of the one-way variable pump 13 is connected to the oil tank 22, and the outlet of the one-way variable pump 13 is connected to the drain line 21.

[0119] Both the cooler 15 and the filter 16 are installed on the oil return line 23;

[0120] The second pressure relay 10.2 is installed on the first channel 17, and the third pressure relay 10.3 is installed on the second channel 18. Both the second pressure relay 10.2 and the third pressure relay 10.3 are connected to the controller 24; the first pressure relay 10.1 is installed on the drain channel 25.

[0121] The first port 6.1 of the hot oil shuttle valve is connected to the first channel 17, the second port 6.2 is connected to the second channel 18, and the third port 6.3 is connected to the third relief valve 5.3. In the hot oil shuttle valve 6, the oil with the higher pressure is always directed to the third port 6.3 of the hot oil shuttle valve 6 via the first port 6.1 and the second port 6.2.

[0122] The oil inlet of the first relief valve 5.1 is connected to the first channel 17, the oil inlet of the second relief valve 5.2 is connected to the second channel 18, and the oil outlets of both the first relief valve 5.1 and the second relief valve 5.2 are connected to the drain channel 25.

[0123] The oil inlet of the third relief valve 5.3 is connected to the third oil port 6.3 of the hot oil shuttle valve, and the oil outlet of the third relief valve 5.3 is connected to the return oil pipeline 23.

[0124] The inlet of the fourth relief valve 5.4 is connected to the drain line 21, and the outlet of the fourth relief valve 5.4 is connected to the oil tank 22.

[0125] The oil outlet of the first check valve 4.1 is connected to the first channel 17, the oil outlet of the second check valve 4.2 is connected to the second channel 18, and the oil inlets of both the first check valve 4.1 and the second check valve 4.2 are connected to the drain channel 25.

[0126] The working process of the hydraulic system of the liquid-driven hydrogen compressor is as follows:

[0127] Servo motor 1 drives bidirectional variable pump 2 to rotate via coupling 3. The oil pumped out through the first port 2.1 of the bidirectional variable pump enters the left chamber of hydraulic cylinder 9 through the first channel 17, flow meter 7, and first oil passage 19, pushing the hydraulic cylinder to move to the right. At the same time, the oil in the right chamber of hydraulic cylinder 9 returns to the second port 2.2 of the bidirectional variable pump through the second oil passage 20 and second channel 18. When hydraulic cylinder 9 needs to reverse direction, servo motor 1 rotates in the opposite direction, driving bidirectional variable pump 2 to reverse through coupling 3. The oil pumped out through the second port 2.2 of the bidirectional variable pump enters the right chamber of hydraulic cylinder 9 through the second channel 18 and second oil passage 20, pushing the hydraulic cylinder 9 to move to the left. At the same time, the oil in the left chamber of hydraulic cylinder 9 enters the first port 2.1 of the bidirectional variable pump through the first oil passage 19, flow meter 7, and first channel 17.

[0128] Furthermore, the three-phase asynchronous motor 12 drives the unidirectional variable pump 13. The oil inlet of the unidirectional variable pump 13 is connected to the oil tank 22, and the oil outlet of the unidirectional variable pump 13 is connected to the drain line 21. The unidirectional variable pump 13 and the accumulator 14 work together to replenish the hydraulic system leakage.

[0129] Furthermore, to further control the temperature rise of the hydraulic system, high-temperature oil can be discharged through the third port 6.3 of the hot oil shuttle valve and the third relief valve 5.3, and then flow through the return oil line 23, cooler 15, and filter 16, finally returning to the oil tank 22. This circuit can actively replace the high-temperature oil in the system, enhance the heat dissipation effect, and thus effectively reduce the overall heat generation of the system.

[0130] In summary, the vibration suppression control method for a liquid-driven hydrogen compressor provided by this invention suppresses system resonance at its source by real-time coordinated control of the servo motor speed and the bidirectional variable pump displacement. Its core is the use of a genetic algorithm to dynamically optimize the control accuracy and operating efficiency of the servo motor and the bidirectional variable pump across multiple objectives. When the load or flow rate changes, it can quickly find a new optimal speed-displacement combination point and adjust the system to operate at that point, ensuring efficient and stable operation of the system under all working conditions and improving energy utilization efficiency. Furthermore, the hydraulic system of the liquid-driven hydrogen compressor uses a hot oil shuttle valve to replace the high-temperature oil, effectively reducing system heat generation. This invention integrates active vibration suppression and efficient thermal management, significantly improving the overall performance of the liquid-driven hydrogen compressor.

[0131] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A vibration suppression control method for a liquid-driven hydrogen compressor, characterized in that, Includes the following steps: S1. Real-time monitoring of the system pressure, flow rate, current servo motor speed, and bidirectional variable pump displacement of the hydraulic system of the liquid-driven hydrogen compressor. S2, the natural frequency of the acquisition system, the resonant frequency of the calculation system, and the instantaneous excitation frequency generated by the current operating conditions; S3. Analyze the system frequency domain to determine the feasible operating range of the servo motor speed and bidirectional variable pump displacement outside the resonant frequency range. S4. Using the feasible working domain as a constraint, establish a multi-objective optimization model that takes into account both system operating efficiency and system control accuracy. S5. Within the feasible working domain, generate an initial population for the genetic algorithm; S6. Using the servo motor speed as the optimization variable, and based on the multi-objective optimization model, perform iterative optimization calculations using a genetic algorithm. S7. From the final population after the iterative optimization, select the individual with the highest fitness as the optimal servo motor speed output. S8. Based on the optimal servo motor speed, calculate the optimal bidirectional variable pump displacement to match it, thereby determining the optimal speed-displacement combination operating point of the system; adjust the servo motor and bidirectional variable pump to work together according to the optimal speed-displacement combination operating point; then, return to step S1 to realize closed-loop vibration suppression control.

2. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S2, the resonant frequency of the system The calculation formula is: ； In the formula, This is the system's natural frequency; Let be the damping ratio of the system.

3. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S3, the feasible operating domain derivation process for the servo motor speed is as follows: To avoid system resonance, the following conditions must be met: ； In the formula, This is the system's natural frequency; This is the resonant frequency of the system; Where z is the instantaneous excitation frequency, z is the number of plungers in the bidirectional variable pump, and n is the servo motor speed; Based on this, the feasible operating domain of the servo motor speed is calculated: ； ； ； The feasible operating range of the servo motor speed is as follows: and ; In the formula, The feasible operating range for servo motor speed. This is the minimum speed of the servo motor. This represents the maximum speed of the servo motor.

4. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S3, the feasible working domain expression for the bidirectional variable pump displacement is: ； In the formula, V represents the real-time displacement of the bidirectional variable pump. This is the maximum displacement of the bidirectional variable pump.

5. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S4, the system operating efficiency model expression is: ； ； ； ； In the formula, For the system operating efficiency model, This is a mechanical efficiency model for a bidirectional variable pump. This is a volumetric efficiency model for a two-way variable pump. This is the efficiency model for the servo motor, where μ is the dynamic viscosity of the oil, p is the outlet pressure of the bidirectional variable pump, and n is the current speed of the servo motor. This is the laminar flow drag coefficient. This is the mechanical resistance coefficient. Let the torque loss constant be... V represents the maximum displacement of the bidirectional variable pump, and V represents the displacement of the bidirectional variable pump. The laminar leakage coefficient is... ω represents the output torque of the servo motor, and ω represents the output speed of the servo motor. For the mechanical losses of the servo motor, For the iron loss of the servo motor, For servo motor copper losses, This refers to the losses incurred by the servo motor driver.

6. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S4, the mathematical model expression for the system control accuracy is: ； In the formula: , where is the stiffness constant of the hydraulic system; , is the volume constant of the bidirectional variable pump; , is a fixed volume constant; , where is the total mass constant; P(n) is the accuracy performance index; This refers to the effective bulk modulus of the oil. The effective area of ​​the hydraulic cylinder piston; The fixed volume of the hydraulic system includes the oil volume of the pipelines and valve bodies; k is the volume ratio coefficient. The equivalent total mass of the hydraulic system; This refers to the rated speed of the servo motor. This is the bandwidth gain coefficient; This is the saturation effect coefficient; This represents the high-speed degradation coefficient.

7. The vibration suppression control method for a liquid-driven hydrogen compressor according to claim 1, characterized in that, In S4, the expression for the multi-objective optimization model is: ； In the formula, h represents the multi-objective optimization model; For system operating efficiency model; A mathematical model for system control accuracy.

8. A hydraulic system for a liquid-driven hydrogen compressor, the hydraulic system for the vibration suppression control method according to any one of claims 1-7, comprising a servo motor (1), a bidirectional variable pump (2), a hydraulic cylinder (9), an oil tank (22), and a first oil circuit (19) and a second oil circuit (20) connected between the bidirectional variable pump (2) and the hydraulic cylinder (9); the servo motor (1) drives the bidirectional variable pump (2), the first port (2.1) of the bidirectional variable pump (2) is connected to one side cavity of the hydraulic cylinder (9) through the first oil circuit (19), and the second port (2.2) of the bidirectional variable pump (2) is connected to the other side cavity of the hydraulic cylinder (9) through the second oil circuit (20); characterized in that, It also includes a hot oil shuttle valve (6), a first relief valve (5.1), a second relief valve (5.2) and a third relief valve (5.3); The hot oil shuttle valve (6) has a first oil port (6.1), a second oil port (6.2), and a third oil port (6.3), wherein the first oil port (6.1) is connected to the first oil circuit (19), the second oil port (6.2) is connected to the second oil circuit (20), and the third oil port (6.3) is connected to the inlet of the third overflow valve (5.3); The inlet of the first overflow valve (5.1) is connected to the first oil circuit (19), the inlet of the second overflow valve (5.2) is connected to the second oil circuit (20), and the outlets of the first overflow valve (5.1) and the second overflow valve (5.2) are both connected to the system's drain line (21); the outlet of the third overflow valve (5.3) is connected to the system's return line (23).

9. The hydraulic system for a liquid-driven hydrogen compressor according to claim 8, characterized in that, The hot oil shuttle valve (6) is configured to always direct the oil at the higher pressure end to its third oil port (6.3) in its first oil port (6.1) and second oil port (6.2).

10. The hydraulic system for a liquid-driven hydrogen compressor according to claim 8 or 9, characterized in that, The return oil pipeline (23) is provided with a cooler (15) and a filter (16) in sequence along the oil flow direction; the outlet of the third overflow valve (5.3) is connected to the return oil pipeline (23), so that the oil discharged from the hot oil shuttle valve (6) can flow through the cooler (15) and the filter (16) in sequence and then return to the oil tank (22).

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