A vibration suppression control method and hydraulic system of a liquid-driven hydrogen compressor

Abstract

The application discloses a kind of vibration suppression control method and hydraulic system of liquid drive hydrogen compressor, belong to hydraulic transmission technical field, the control method is through real-time coordinated control servo motor speed and bidirectional variable pump displacement, from source inhibits system resonance, its core is to adopt genetic algorithm to the control precision and operating efficiency of servo motor and bidirectional variable pump are multi-objective dynamic optimization, when load or flow changes, new optimal speed-displacement combination point can be quickly found and the system is adjusted to the point work, ensure that system can be efficiently, smoothly run under all conditions, improve energy utilization efficiency;The hydraulic system adopts hot oil shuttle valve to replace high-temperature oil, effectively reduces system heating.The application integrates active vibration suppression and efficient thermal management, significantly improves the comprehensive performance of liquid drive hydrogen compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic transmission, and in particular to a vibration suppression control method and hydraulic system of a liquid-driven hydrogen compressor. BACKGROUND

[0002] Hydrogen compressors are key equipment in the hydrogen energy industry chain, and bear the core functions of hydrogen pressure increase, storage and transportation. Liquid-driven hydrogen compressors (referred to as liquid-driven hydrogen compressors) change the volume of gas by hydraulic pistons to achieve compression, have the advantages of high output pressure and wide flow regulation range, and have become the mainstream technical route in hydrogen refueling stations and other scenarios.

[0003] The current liquid-driven hydrogen compressor generally uses a hydraulic drive system based on fixed parameter PID control to control the reciprocating motion of the hydraulic cylinder through a pre-set program to achieve gas compression. The system usually includes a hydraulic power unit, a compression cylinder body with direct gas-liquid contact, and a matching control valve group, and its working process is controlled by a pre-set pressure-flow curve.

[0004] The existing technology has three outstanding defects: first, the dynamic instability of the gas-liquid coupling interface can cause severe water hammer effect and high-frequency pressure impact; second, the hydraulic system lacks adaptive adjustment capability when switching between wide frequency conditions, resulting in transient response disorder; third, the control strategy under load mutation conditions is single and cannot achieve dynamic compensation. These problems together cause strong vibration and noise of the system, not only accelerating the fatigue damage of the mechanical structure and the failure of the sealing element, but also causing significant increase in energy consumption, which seriously restricts the reliability, service life and operation economy of the equipment. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a vibration suppression control method and hydraulic system of a liquid-driven hydrogen compressor, by analyzing the vibration mechanism of the liquid-driven hydrogen compressor, establishing a liquid-driven hydrogen compressor operation efficiency model and a control precision mathematical model, and optimizing the control precision of the liquid-driven hydrogen compressor through an optimization algorithm, the speed of the servo motor and the displacement of the bidirectional variable pump are coordinated controlled, the control precision of the liquid-driven hydrogen compressor is improved under the premise of ensuring the operation efficiency and working performance, the system vibration impact can be effectively suppressed, and the high reliability of the liquid-driven hydrogen compressor is improved, the service life of the liquid-driven hydrogen compressor is prolonged.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is:

[0007] A vibration suppression control method of a liquid-driven hydrogen compressor, comprising the following steps:

[0008] S1, real-time detection of the system pressure, flow, current time servo motor speed and bidirectional variable pump displacement of the liquid-driven hydrogen compressor hydraulic system;

[0009] S2, collect the inherent frequency of the system, calculate the resonance frequency of the system and the instantaneous excitation frequency generated by the current working condition;

[0010] S3, analyze the frequency domain of the system to determine the feasible working domain of the servo motor speed and the bi-directional variable pump displacement outside the resonance frequency interval;

[0011] S4, establish a multi-objective optimization model considering system operation efficiency and system control accuracy as a constraint condition;

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

[0013] S6, taking the servo motor speed as the optimization variable, based on the multi-objective optimization model, the genetic algorithm is used for iterative optimization calculation;

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

[0015] S8, according to the optimal servo motor speed, the optimal bi-directional variable pump displacement matched with it is calculated, so as to determine the optimal speed-displacement combination working point of the system; according to the optimal speed-displacement combination working point, the servo motor and the bi-directional variable pump are adjusted to cooperate; then, return to step S1 to realize closed-loop vibration suppression control.

[0016] The further improvement of the technical scheme of the application is that in S2, the resonance frequency of the system The calculation formula is:

[0017]

[0018] In the formula, is the inherent frequency of the system; is the damping ratio of the system.

[0019] The further improvement of the technical scheme of the application is that in S3, the feasible working domain of the servo motor speed is derived as follows:

[0020] In order to avoid the resonance of the system, the following conditions should be met:

[0021]

[0022] In the formula, is the inherent frequency of the system; is the resonance frequency of the system; is the instantaneous excitation frequency, z is the number of bi-directional variable pump plungers, and n is the servo motor speed;

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

[0024]

[0025]

[0026]

[0027] The feasible working domain of the servo motor speed is as follows:

[0028] And ;

[0029] In the formula, is the feasible working domain of the servo motor speed, is the minimum value of the servo motor speed, is the maximum value of the servo motor speed.

[0030] Further improvement of the technical scheme of the application is that in S3, the expression of the feasible working domain of the displacement of the bidirectional variable pump is:

[0031]

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

[0033] Further improvement of the technical scheme of the application is that in S4, the expression of the system operation efficiency model is:

[0034]

[0035]

[0036]

[0037]

[0038] In the formula, is the system operation efficiency model, is the mechanical efficiency model of the bidirectional variable pump, is the volumetric efficiency model of the bidirectional variable pump, is the servo motor efficiency model, μ is the dynamic viscosity of oil, p is the outlet pressure of the bidirectional variable pump, n is the current servo motor speed, is the laminar flow resistance coefficient, is the mechanical resistance coefficient, is the torque loss constant, is the maximum displacement of the bidirectional variable pump, V is the displacement of the bidirectional variable pump, is the laminar flow leakage coefficient, is the output torque of the servo motor, ω is the output rotating speed of the servo motor, is the mechanical loss of the servo motor, is the iron loss of the servo motor, is the copper loss of the servo motor, is the driver loss of the servo motor.

[0039] Further improvement of the technical scheme of the present application is that in S4, the expression of the system control precision mathematical model is:

[0040]

[0041] In the formula, h is the multi-objective optimization model, is the stiffness constant of the hydraulic system; is the volume constant of the bidirectional variable pump; is the fixed volume constant; is the total mass constant; P(n) is the precision performance index; is the effective volume elastic modulus of the oil; is the effective area of the hydraulic cylinder piston; is the fixed volume of the hydraulic system, including the oil volume of the pipeline and the valve body; k is the volume proportion coefficient; is the equivalent total mass of the hydraulic system; is the rated rotating speed of the servo motor; is the bandwidth gain coefficient; is the saturation effect coefficient; is the high-speed deterioration coefficient.

[0042] Further improvement of the technical scheme of the present application is that in S4, the expression of the multi-objective optimization model is:

[0043]

[0044] In the formula, h is the multi-objective optimization model, is the system operation efficiency model; is the system control precision mathematical model.

[0045] A hydraulic drive hydrogen compressor hydraulic system comprises a servo motor, a bidirectional variable pump, a hydraulic cylinder, an oil tank and a first oil path and a second oil path connected between the bidirectional variable pump and the hydraulic cylinder; the servo motor is drivingly connected to the bidirectional variable pump, a first oil port of the bidirectional variable pump is connected to one side cavity of the hydraulic cylinder through the first oil path, and a second oil port of the bidirectional variable pump is connected to the other side cavity of the hydraulic cylinder through the second oil path;

[0046] Further, the hydraulic system further comprises a hot oil shuttle valve, a first overflow valve, a second overflow valve and a third overflow valve.

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

[0048] The oil inlet of the first overflow valve is connected to the first oil path, the oil inlet of the second overflow valve is connected to the second oil path, and the oil outlets of the first overflow valve and the second overflow valve are both connected to the oil drain pipeline of the system; and the oil outlet of the third overflow valve is connected to the oil return pipeline of the system.

[0049] The further improvement of the technical scheme of the present application is that the hot oil shuttle valve is configured to always guide the oil liquid of the side with higher pressure in the hot oil shuttle valve first oil port and the hot oil shuttle valve second oil port to the hot oil shuttle valve third oil port.

[0050] The further improvement of the technical scheme of the present application is that the oil return pipeline is sequentially provided with a cooler and a filter along the oil liquid flow direction; and the oil outlet of the third overflow valve is connected to the oil return pipeline, so that the oil liquid guided from the hot oil shuttle valve can sequentially flow through the cooler and the filter and then return to the oil tank.

[0051] Thanks to the above technical scheme, the present application has the following technical progress:

[0052] 1. The vibration suppression control method of the liquid-driven hydrogen compressor provided by the present application reduces system resonance from the source by coordinating the control of the servo motor speed and the displacement of the bidirectional variable pump, thereby improving energy utilization efficiency compared with the passive vibration suppression method.

[0053] 2. The vibration suppression control method of the liquid-driven hydrogen compressor provided by the present application uses a genetic algorithm to perform multi-objective dynamic optimization on the control accuracy and working efficiency of the servo motor and the bidirectional variable pump, so that when the load or flow changes, the optimization can be quickly performed under new working conditions to obtain a new speed-displacement combination point with high efficiency and high control accuracy, and the servo motor and the bidirectional variable pump are adjusted to work at the speed-displacement combination point.

[0054] 3. The hydraulic system of the liquid-driven hydrogen compressor provided by the present application uses a hot oil shuttle valve to replace the high-temperature oil liquid in the hydraulic system, thereby reducing the heating problem of the hydraulic system while ensuring normal operation. BRIEF DESCRIPTION OF DRAWINGS

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0056] Figure 1 is a flow chart of a vibration suppression control method of a liquid-driven hydrogen compressor provided in an embodiment of the present application;

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

[0058] In the drawings: 1, servo motor; 2, bidirectional variable pump; 2.1, first oil port of bidirectional variable pump; 2.2, second oil port of bidirectional variable pump; 2.3, third oil port of bidirectional variable pump; 3, shaft coupling; 4.1, first check valve; 4.2, second check valve; 5.1, first overflow valve; 5.2, second overflow valve; 5.3, third overflow valve; 5.4, fourth overflow valve; 6, hot oil shuttle valve; 6.1, first oil port of hot oil shuttle valve; 6.1, second oil port of hot oil shuttle valve; 6.3, third oil port of 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 hole; 18, second hole; 19, first oil path; 20, second oil path; 21, oil drain pipeline; 22, oil tank; 23, oil return pipeline; 24, controller; 25, oil drain hole; 26, leakage hole. DETAILED DESCRIPTION

[0059] It should be noted that the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0060] In the description of the present application, it needs to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0061] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "several" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] The present application will be further described in detail below in conjunction with the drawings and examples:

[0063] As shown in the figure, a vibration suppression control method of a liquid-driven hydrogen compressor, comprising the following steps: Figure 1

[0064] S1, real-time detection of system pressure, flow, current time servo motor speed and bidirectional variable pump displacement of the hydraulic system of the liquid-driven hydrogen compressor;

[0065] S2, collecting the natural frequency of the system, calculating the resonance frequency of the system and the instantaneous excitation frequency generated by the current working condition;

[0066] The formula for calculating the resonance frequency of the system is:

[0067]

[0068] In the formula, is the natural frequency of the system; is the damping ratio of the system.

[0069] S3, analyzing the frequency domain of the system to determine the feasible working domain of the servo motor speed and the bidirectional variable pump displacement outside the resonance frequency interval;

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

[0071] In order to avoid resonance of the system, the following conditions should be met:

[0072]

[0073] In the formula,​​ is the natural frequency of the system; is the resonance frequency of the system; is the instantaneous excitation frequency,

[0074] z is the number of bidirectional variable pump plungers, n is the servo motor speed;

[0075] Based on this, the feasible working domain of the servo motor speed is calculated:

[0076]

[0077]

[0078]

[0079] The feasible working domain of the servo motor speed is as follows:

[0080] And ;

[0081] In the formula, is the feasible working domain of the servo motor speed, is the minimum value of the servo motor speed, is the maximum value of the servo motor speed.

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

[0083]

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

[0085] S4, taking the feasible working domain as the constraint condition, a multi-objective optimization model considering system operation efficiency and system control accuracy is established;

[0086] The expression of the system operation efficiency model is:

[0087]

[0088]

[0089]

[0090]

[0091] In the formula, is the system operation efficiency model, is the mechanical efficiency model of the bidirectional variable pump, is the volumetric efficiency model of the bidirectional variable pump, is the servo motor efficiency model, 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, is the laminar flow resistance coefficient, is the mechanical resistance coefficient, is the torque loss constant, is the maximum displacement of the bidirectional variable pump, and V is the displacement of the bidirectional variable pump, is the laminar flow leakage coefficient, is the output torque of the servo motor, and ω is the output speed of the servo motor, is the mechanical loss of the servo motor, is the iron loss of the servo motor, is the copper loss of the servo motor, is the driver loss of the servo motor.

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

[0093]

[0094] In the formula: is the stiffness constant of the hydraulic system; is the volumetric constant of the bidirectional variable pump; is the fixed volumetric constant; is the total mass constant; and P(n) is the accuracy performance index; is the effective bulk modulus of the oil; is the effective area of the hydraulic cylinder piston; is the fixed volume of the hydraulic system, including the oil volume of the pipeline and the valve body that does not change; and k is the volumetric proportion coefficient; is the equivalent total mass of the hydraulic system; is the rated speed of the servo motor; is the bandwidth gain coefficient; is the saturation effect coefficient; is the high-speed degradation coefficient.

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

[0096]

[0097] In the formula, h is the multi-objective optimization model; is the system operation efficiency model; is the system control accuracy mathematical model.

[0098] S5. Generating an initial population for the genetic algorithm in the feasible working domain;

[0099] S6, taking the servo motor speed as the optimization variable, based on the multi-objective optimization model, using genetic algorithm for iterative optimization calculation;

[0100] S7, from the final population after the end of the iterative optimization, select the highest fitness individual as the optimal servo motor speed output;

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

[0102] The servo motor speed n is set as the optimization variable, the floating point coding method is adopted, the initial population of genetic algorithm is generated in the feasible solution space, and the fitness of each individual in the population is calculated .

[0103] The fitness The calculation formula is as follows:

[0104]

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

[0106] Then, selection, crossover and mutation operations are performed on the population to generate a new generation of population, and the fitness of each individual in the population is re-evaluated. Repeat the evolution process, when the optimal fitness of the population of consecutive generations does not appear significant improvement, then terminate the iteration, and select the highest fitness individual as the optimal servo motor speed output.

[0107] S8, according to the optimal servo motor speed, the optimal bidirectional variable pump displacement matched with it is calculated, so as to determine the optimal speed-displacement combination working point of the system; according to the optimal speed-displacement combination working point, the servo motor and the bidirectional variable pump are adjusted to run cooperatively; then, return to step S1, realize closed-loop vibration suppression control.

[0108] According to the optimal servo motor speed, the optimal bidirectional variable pump displacement matched with it is calculated, the calculation method is as follows:

[0109]

[0110] In the formula, is the optimal bidirectional variable pump displacement, Q is the system flow (measured in S1), is the optimal servo motor speed.

[0111] As Figure 2As shown, a kind of hydraulic system of liquid drive hydrogen compressor, including servo motor 1, bidirectional variable pump 2 (with bidirectional variable pump first oil port 2.1, bidirectional variable pump second oil port 2.2 And bidirectional variable pump third oil port 2.3), coupling 3, first check valve 4.1, second check valve 4.2, first overflow valve 5.1, second overflow valve 5.2, third overflow valve 5.3, fourth overflow valve 5.4, hot oil shuttle valve 6 (with hot oil shuttle valve first oil port 6.1, hot oil shuttle valve second oil port 6.2 And hot oil shuttle valve third oil port 6.3), flowmeter 7, valve block 8, hydraulic cylinder 9, first pressure relay 10.1, second pressure relay 10.2, third pressure relay 10.3, temperature sensor 11, three-phase asynchronous motor 12, unidirectional variable pump 13, energy accumulator 14, cooler 15, filter 16, first hole 17, second hole 18, first oil path 19, second oil path 20, oil drain line 21, oil tank 22, oil return line 23, controller 24, oil drain hole 25, leakage hole 26.

[0112] Servo motor 1 and bidirectional variable pump 2 are connected with controller 24;

[0113] First hole 17, second hole 18, oil drain hole 25 and leakage hole 26 are arranged in valve block 8;The output shaft of servo motor 1 is connected with the input shaft of bidirectional variable pump 2 by coupling 3;The oil port of bidirectional variable pump 2 is installed with the wall surface of valve block 8;Bidirectional variable pump first oil port 2.1 is connected with hydraulic cylinder 9 by first hole 17 and first oil path 19 in sequence;Bidirectional variable pump second oil port 2.2 is connected with hydraulic cylinder 9 by second hole 18 and second oil path 20 in sequence;Bidirectional variable pump third oil port 2.3 is connected with leakage hole 26;Oil drain hole 25 is connected with oil drain line 21;Leakage hole 26 is connected with oil return line 23;

[0114] Energy accumulator 14 is connected with oil drain line 21;

[0115] Flowmeter 7 is connected in series on first hole 17, and flowmeter 7 is connected with controller 24;

[0116] Temperature sensor 11 is arranged on oil drain hole 25;

[0117] Three-phase asynchronous motor 12 is coaxially connected with unidirectional variable pump 13;

[0118] The oil inlet of unidirectional variable pump 13 is connected with oil tank 22, and the oil outlet of unidirectional variable pump 13 is connected with oil drain line 21;

[0119] Cooler 15 and filter 16 are arranged on oil return line 23;

[0120] The second pressure relay 10.2 is arranged on the first hole 17, the third pressure relay 10.3 is arranged on the second hole 18, and the second pressure relay 10.2 and the third pressure relay 10.3 are connected with the controller 24; the first pressure relay 10.1 is arranged on the oil drain hole 25;

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

[0122] The oil inlet of the first overflow valve 5.1 is connected with the first hole 17, the oil inlet of the second overflow valve 5.2 is connected with the second hole 18, and the oil outlets of the first overflow valve 5.1 and the second overflow valve 5.2 are connected with the oil drain hole 25;

[0123] The oil inlet of the third overflow valve 5.3 is connected with the third oil port 6.3 of the hot oil shuttle valve, and the oil outlet of the third overflow valve 5.3 is connected with the oil return line 23;

[0124] The oil inlet of the fourth overflow valve 5.4 is connected with the oil drain line 21, and the oil outlet of the fourth overflow valve 5.4 is connected with the oil tank 22;

[0125] The oil outlet of the first one-way valve 4.1 is connected with the first hole 17, the oil outlet of the second one-way valve 4.2 is connected with the second hole 18, and the oil inlets of the first one-way valve 4.1 and the second one-way valve 4.2 are connected with the oil drain hole 25.

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

[0127] The servo motor 1 drives the bidirectional variable pump 2 to rotate through the coupling 3, the oil pumped out of the first oil port 2.1 of the bidirectional variable pump passes through the first hole 17, the flow meter 7 and the first oil line 19 to enter the left cavity of the hydraulic cylinder 9, and drives the hydraulic cylinder to move to the right. At the same time, the oil in the right cavity of the hydraulic cylinder 9 returns to the second oil port 2.2 of the bidirectional variable pump through the second oil line 20 and the second hole 18. When the hydraulic cylinder 9 needs to reverse, the servo motor 1 reverses rotation, and drives the bidirectional variable pump 2 to reverse through the coupling 3. The oil pumped out of the second oil port 2.2 of the bidirectional variable pump passes through the second hole 18 and the second oil line 20 to enter the right cavity of the hydraulic cylinder 9, and drives the hydraulic cylinder 9 to move to the left. At the same time, the oil in the left cavity of the hydraulic cylinder 9 enters the first oil port 2.1 of the bidirectional variable pump through the first oil line 19 and the flow meter 7.

[0128] Further, the three-phase asynchronous motor 12 drives the one-way variable pump 13, the oil inlet of the one-way variable pump 13 is connected with the oil tank 22, the oil outlet of the one-way variable pump 13 is connected with the oil drain pipeline 21, and the one-way variable pump 13 and the accumulator 14 jointly supplement oil for the hydraulic system leakage.

[0129] Further, in order to further control the temperature rise of the hydraulic system, the high-temperature oil can be led out through the third oil port 6.3 of the hot oil shuttle valve and the third overflow valve 5.3, then flow through the cooler 15 and the filter 16 through the oil return pipeline 23, and finally return to the oil tank 22. This circuit can actively replace the oil with higher temperature in the system, strengthen the heat dissipation effect, and thus effectively reduce the overall heating of the system.

[0130] In summary, the vibration suppression control method of the liquid-driven hydrogen compressor provided by the application is to suppress system resonance from the source by real-time coordinated control of the servo motor speed and the bidirectional variable pump displacement, and the core is to use the genetic algorithm to perform multi-objective dynamic optimization on the control accuracy and operation efficiency of the servo motor and the bidirectional variable pump. When the load or flow changes, a new optimal speed-displacement combination point can be quickly found and the system can be adjusted to work at this point, so that the system can be efficiently and stably operated under all working conditions, and the energy utilization efficiency is improved. The hydraulic system of the liquid-driven hydrogen compressor uses the hot oil shuttle valve to replace the high-temperature oil, which effectively reduces the heating of the system. The application integrates active vibration suppression and efficient thermal management, which significantly improves the comprehensive 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 application, and not to limit them; although the application has been described in detail with reference to the above embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A method for suppressing vibration of a liquid-driven hydrogen compressor, characterized by, The method comprises the following steps: S1, real-time detection of the system pressure, flow, current time servo motor speed and bi-directional variable pump displacement of the hydraulic system of the liquid-driven hydrogen compressor; S2, acquisition of the inherent frequency of the system, calculation of the resonance frequency of the system and the instantaneous excitation frequency generated by the current working condition; S3, analysis of the frequency domain of the system to determine the feasible working domain of the servo motor speed and the bi-directional variable pump displacement outside the resonance frequency interval; S4, establishing a multi-objective optimization model considering system operation efficiency and system control accuracy as a constraint condition; The system operation efficiency model expression is: In the formula, is a system operation efficiency model, is a mechanical efficiency model of a bidirectional variable pump, is a volumetric efficiency model of a bidirectional variable pump, is a servo motor efficiency model, is an oil dynamic viscosity, is an outlet pressure of a bidirectional variable pump, n is a current time servo motor speed, is a laminar flow resistance coefficient, is a mechanical resistance coefficient, is a torque loss constant, is a maximum displacement of a bidirectional variable pump, V is a displacement of a bidirectional variable pump, is a laminar flow leakage coefficient, is a servo motor output torque, is a servo motor output speed, is a servo motor mechanical loss, is a servo motor iron loss, is a servo motor copper loss, is a servo motor driver loss; The system control accuracy mathematical model expression is: In the formula: is the hydraulic system stiffness constant; is the bidirectional variable pump volume constant; is the fixed volume constant; is the total mass constant; P(n) is the precision performance index; is the effective volume modulus of oil; is the effective area of the hydraulic cylinder piston; is the hydraulic system fixed volume, including the oil volume of the pipeline and the valve body constant part; k is the volume proportionality coefficient; is the equivalent total mass of the hydraulic system; is the rated speed of the servo motor; is the bandwidth gain coefficient; is the saturation effect coefficient; is the high-speed degradation coefficient; The multi-objective optimization model expression is: In the formula, h is a multi-objective optimization model; is a system operation efficiency model; is a system control accuracy mathematical model; S5, generating an initial population for genetic algorithm in the feasible working domain; S6, taking the servo motor speed as the optimization variable, performing iterative optimization calculation based on the multi-objective optimization model by using genetic algorithm; S7, selecting the individual with the highest fitness from the final population after iterative optimization to output the optimal servo motor speed; S8, calculating the optimal bi-directional variable pump displacement matched with the optimal servo motor speed to determine the optimal speed-displacement combined working point of the system, adjusting the servo motor and the bi-directional variable pump to run cooperatively according to the optimal speed-displacement combined working point, and then returning to step S1 to realize closed-loop vibration suppression control.

2. The method of claim 1, wherein the method further comprises: In S2, the resonance frequency of the system is calculated by the formula: wherein is the natural frequency of the system; is the damping ratio of the system.

3. The method of claim 1, wherein the method further comprises: In S3, the derivation process of the feasible working domain of the servo motor speed is as follows: To avoid system resonance, the following conditions should be met: wherein is the natural frequency of the system; is the resonant frequency of the system; is the instantaneous excitation frequency, z is the number of bi-directional variable pump plungers, and n is the servo motor speed; Based on this, the feasible working domain of the servo motor speed is calculated as follows: The feasible working domain of the servo motor speed is as follows: and wherein is the minimum value of the servo motor speed, is the minimum value of the servo motor speed, is the maximum value of the servo motor speed.

4. The method of claim 1, wherein the method further comprises: In S3, the expression of the feasible working domain of the bi-directional variable pump displacement is as follows: wherein ; is the real-time displacement of the bidirectional variable pump, is the maximum displacement of the bidirectional variable pump.

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