A vibration active control system and vibration control method

Abstract

The application discloses a kind of vibration active control system and vibration control method, motion transmission mechanism and permanent magnet motor rotor rotation mass are equivalent separated, equivalent into proportional to relative acceleration's inerter parameter, the actuating force of execution structure is analyzed as the synthesis of electromagnetic force and inertia force;According to the frequency band design of vibration source, the influence of rotation mass is analyzed, so as to effectively utilize inertia mass to realize vibration control, while under the allowable torque of motion transmission structure, inertia mass is reduced as far as possible, so as to avoid the problem of commutation impact caused by high-frequency inertia force;The vibration control method proposed by the application is performed on the subsystem dynamics modeling of the proposed mutually coupled electromechanical structure system according to module, and the equivalent damping coefficient of pure resistance load semi-active control is derived by analyzing the coupling relationship, and the damping coefficient regulation mechanism of the dynamics structure system is revealed, which is the core content of the application based on system structure and the most significant feature of the application.

Description

Technical Field

[0001] This invention belongs to the field of vibration isolation technology, specifically relating to an active vibration control system and a vibration control method. Background Technology

[0002] Vibration control is a challenging problem in many engineering fields, with active vibration control in building structures, bridges, and vehicle suspensions being a hot research topic. Active vibration control schemes fall into two categories: active control that injects energy and semi-active control that achieves vibration control solely by dissipating vibration energy. The key to solving active vibration control lies in an engineerable and highly reliable actuator system. Currently, active control actuators are mainly pneumatic, hydraulic, electric, or hybrid (hydraulic, pneumatic, and electric), and in China, these are still in the laboratory prototype research stage. Semi-active control is mainly achieved through adjustable damping dampers; mature products abroad include continuous damping control (CDC) and magnetorheological dampers (MRC). Summary of the Invention

[0003] In view of this, the purpose of the present invention is to provide an active vibration control system and a vibration control method, in which the dynamics of each functional module are coordinated and cooperated to achieve active vibration control.

[0004] An active vibration control system comprises six main modules: a vibration source, a motion transmission mechanism, a PMSM permanent magnet motor, a three-phase rectifier bridge, a step-up / step-down voltage circuit, and a load.

[0005] In a mechanical vibration structure, the vertical velocity of the vibration source is converted into rotational motion by a motion transmission mechanism, and then converted into the rotational speed of the motor shaft by a motion transmission mechanism and input to the PMSM permanent magnet motor. The PMSM permanent magnet motor generates an induced electromotive force under the excitation of the rotational speed. The three-phase voltage signal of the induced electromotive force is converted into DC voltage by a rectifier bridge, and finally converted by a step-up / step-down circuit and applied to the load.

[0006] Vibration control of mechanical structures is achieved by adjusting the duty cycle of the boost / buck circuit.

[0007] Furthermore, it also includes battery loads or supercapacitor loads to achieve vibration energy recovery.

[0008] A vibration control method based on the above-mentioned active vibration control system, which, according to the degree of vibration control of the mechanical vibration structure, i.e., based on the equivalent damping coefficient... To determine the duty cycle of the boost / buck circuit, where the duty cycle D is related to the equivalent damping coefficient. The relationship is as follows:

[0009] ;

[0010] In the above formula, This represents the relationship between the input and output voltages in a boost / buck circuit. The transmission ratio of the motion transmission mechanism. The transmission efficiency of the motion transmission mechanism. This represents the number of pole pairs of the motor. For the stator flux linkage of the motor, The length of the horizontal arm in the motion transmission mechanism that converts vertical motion into rotational motion. For stator resistance, This is the resistance value of the load resistor. This is the motor power factor.

[0011] The present invention has the following beneficial effects:

[0012] This invention effectively separates the rotational mass of the motion transmission mechanism and the permanent magnet motor rotor into an equivalent inertial capacitance parameter proportional to the relative acceleration. The working force of the actuator is analyzed as a synthesis of electromagnetic force and inertial force. The influence of rotational mass can be designed and analyzed according to the frequency band of the vibration source, thereby effectively utilizing inertial mass to achieve vibration control. At the same time, under the allowable torque of the motion transmission structure, the inertial mass is minimized to avoid the commutation impact caused by high-frequency inertial force.

[0013] The vibration control method proposed in this invention performs subsystem dynamic modeling of the proposed mutually coupled electromechanical structure system by module, and derives the equivalent damping coefficient of semi-active control of pure resistive load by analyzing its coupling relationship. It reveals the regulation mechanism of the damping coefficient of the dynamic structure system, which is the core content of this invention based on the system structure and is the most significant feature of this invention.

[0014] The system of this invention can achieve semi-active control by providing an equivalent damping coefficient, and can also achieve active control by controlling a permanent magnet motor. Unlike hydraulic and pneumatic actuator structures, the system of this invention can significantly reduce the energy demand for active control by finding a suitable control algorithm that enables active control to be mainly achieved through motor power feeding.

[0015] The present invention also lies in changing the voltage and current of the load by controlling the boost / buck circuit, thereby meeting the charging requirements of the battery or supercapacitor. Attached Figure Description

[0016] Figure 1 For the mechanical model of the vibration system;

[0017] Figure 2 This is a block diagram of the vibration active control system of the present invention.

[0018] Figure 3This is the circuit topology within one cycle in an embodiment of the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0020] This invention proposes an active control structure system capable of both active and semi-active control. This structure couples the mechanical energy of vibration with the electrical energy of a permanent magnet motor, controlling the mutual transfer of vibration energy. Under the premise of energy conservation, a mechanical gearbox achieves coupling and balance of torque and speed in the electromechanical equipment. Output voltage and current control can be achieved through boost / buck circuits and load matching. The vibration control system proposed in this invention is essentially a type of electromechanical coupled energy conversion system. Active control occurs when the permanent magnet motor operates in motor mode, while semi-active control occurs when it operates in generator mode. Semi-active control is achieved by actively adjusting the duty cycle of the boost / buck circuit in the motor load circuit. If a battery or supercapacitor load is connected, vibration energy can be recovered; if a purely resistive load is connected, it functions similarly to a conventional vibration damper, with vibration energy dissipated as heat. This invention not only proposes a structural system for active vibration control but also provides a method for wide-range damping coefficient adjustment under purely resistive load conditions—namely, the derivation of the equivalent damping coefficient. Using the equivalent damping coefficient adjustment mechanism provided in this invention, semi-active control can be achieved.

[0021] I. Composition and Principle of Vibration Active Control System

[0022] Figure 1 For the mechanical model of a single-degree-of-freedom vibration system with added electromechanical actuators, all vibration problems can be equivalent to or include this vibration model. This represents the vertical displacement of the base. The vertical displacement of the vibration-absorbing mass block. The mass of the vibration-absorbing mass block. For the spring stiffness, the equivalent force of the electromechanical actuator in semi-active mode can be equivalent to the combination of inertial capacitive force and damping force. The equivalent inertia coefficient, This is the equivalent damping coefficient.

[0023] Figure 2 This invention presents an active vibration control system. It consists of six main modules: a vibration source containing an equivalent electromechanical actuator, a motion transmission mechanism, a PMSM permanent magnet motor, a three-phase rectifier bridge, a step-up / step-down voltage circuit, and a load. Its working principle and their inter-coupling relationships are as follows:

[0024] The base of the mechanical vibration structure under the excitation signal Vibration is generated, and the vertical velocity between the moving mass and the base is converted into rotational motion via a motion transmission mechanism, and then transmitted through a transmission ratio of... The motion transmission mechanism is converted into the motor shaft speed. The input is given to the permanent magnet synchronous motor, which generates an induced electromotive force under the excitation of its rotational speed. The three-phase voltage signal is then converted into DC voltage by a rectifier bridge. After passing through a boost / buck circuit, it is converted to The load generates current. The current that reacts back to the step-up / step-down circuit corresponds to the current. , The current fed back to the motor by the rectifier bridge corresponds to the direct-axis and quadrature-axis currents. The motor then generates a corresponding electromagnetic torque based on this current. The output mechanical torque of the motor can be calculated from the input speed signal. Transformed through motion transmission structure It acts on the mechanical vibration structure.

[0025] II. Module Dynamics and Coupling Relationships

[0026] (1) Motion transmission mechanism

[0027] The transmission ratio of the motion transmission mechanism is The transmission efficiency is The length of the horizontal arm that converts vertical motion into rotational motion is Then we have:

[0028] (1)

[0029] (2); where, For mechanical torque, For the actuator to exert force on the moving mass at high speed This refers to the rotational speed of the motor shaft. For mass blocks vertical velocity, Let be the vertical velocity of the base. It is the relative kinetic velocity.

[0030] (2) Dynamics of permanent magnet motors and electromechanical coupling of vibration sources

[0031] Following the conventions for generators, the motion equations of a permanent magnet synchronous motor can be obtained:

[0032] (3)

[0033] In the formula, For the electromagnetic torque of the motor, Let the system's equivalent moment of inertia be:

[0034] (4)

[0035] In the formula, For equivalent inertia, , .

[0036] (5)

[0037] In the formula, For extreme logarithms, For the stator flux linkage of the motor, , For direct-axis and quadrature-axis currents, , These are direct-axis and quadrature-axis inductors, respectively.

[0038] , Then it can be obtained from the voltage equation:

[0039] (6)

[0040] In the formula, , For direct-axis and quadrature-axis voltages, This is the stator resistance.

[0041] (7)

[0042] (8)

[0043] In the formula, Zero-axis current, , , It is a three-phase current. The angle by which the q-axis lags behind the a-phase axis. , ω is the rotor's electric angular velocity.

[0044] (3) Three-phase rectifier bridge

[0045] In the rectifier bridge section, the current and voltage relationship is as follows:

[0046] (9)

[0047] (10)

[0048] In the formula, , These are the rectified DC voltage and DC current. , These are the root mean square values ​​of the phase voltage and phase current. , For parameters, , .

[0049] (4) Boost / buck circuit

[0050] There are various structural implementations of boost / buck circuits. This invention uses... Figure 2 Taking the boost / buck circuit topology shown in the diagram as an example for specific analysis, this circuit consists of two MOSFETs. , Two diodes , Output filter capacitor and an inductor energy storage current converter Composition. The three-phase electricity generated by the motor is rectified and converted into direct current. Positive voltage terminal connected to MOSFET The drain of the circuit has a gate that receives a PWM wave generated according to the duty cycle, and the source is connected in series with an inductor. Then connect a diode anode, diode The cathode is connected to the circuit load, and the diode is also included. Cathode connected to MOSFET and inductor Between, anode and Negative voltage connection; MOSFET The drain is connected to the inductor and diodes Between, source and Negative voltage connection, its gate also receives the PWM wave generated according to the duty cycle D; capacitor Connected in parallel with the load, with one end connected to a diode. Cathode, the other end connected Negative voltage.

[0051] exist Internally, the input power charges the inductor through the inductor, and the inductor stores energy. At this time, we have:

[0052] (11)

[0053] exist Internally, the inductor can supply power to the output, at which point:

[0054] (12)

[0055] Using the idea of ​​average approximation, in one switching cycle Inside We can obtain:

[0056] (13)

[0057] The relationship between the input and output voltages can then be obtained as follows:

[0058] (14)

[0059] If other forms of boost / buck circuits are used, If the function representing the relationship between input and output voltages is given, then the input and output voltages can be expressed as:

[0060] (15)

[0061] At this time, the duty cycle This indicates the ratio of the turn-on time to the turn-off time of the boost / buck circuit.

[0062] In this invention, when the duty cycle is greater than 0.5, the boost / buck circuit is used for boosting voltage, and vice versa.

[0063] III. Derivation of Equivalent Damping Coefficient

[0064] When the motor is directly connected to a three-phase resistive load, the electrical energy is dissipated in the resistance. In this case:

[0065] (16)

[0066] Substituting into the voltage equation, we can base it on The expressions for the equivalent q-axis and d-axis currents are:

[0067] (17)

[0068] in, Vibration source velocity Under normal circumstances, it is generally less than 2 ,and The load resistor has a resistance of 75Ω, therefore it can be considered... much smaller If it can be ignored, then This can be expressed as:

[0069] (18)

[0070] because ,but It can be represented as:

[0071] (19)

[0072] Then the force equivalent to electromagnetic torque It can be represented as:

[0073] (20)

[0074] Therefore, the equivalent damping coefficient for:

[0075] (twenty one)

[0076] We can consider it as the equivalent mechanical damping coefficient of a resistive load directly connected to the terminal of a permanent magnet synchronous motor. However, in this case, the load resistance needs to be changed. Only then can the damping coefficient be changed, and when a larger damping coefficient is required, it must be... The setting is too small, which is inconsistent with engineering practice. However, the present invention uses a step-up / step-down circuit that can... The damping coefficient can be adjusted by changing the duty cycle D while keeping the current constant, which greatly expands the adjustment range and makes it easier to control.

[0077] From equation (14), it can be seen that the input and output voltage relationship of the boost / buck circuit in this invention is as follows: Assume the motor is directly connected to a three-phase load. Power at time The electromagnetic torque is The power of the motor after connecting to the rectifier bridge and then to the step-up / step-down circuit is: The electromagnetic torque is Then we have:

[0078] (twenty two)

[0079] (twenty three)

[0080] In the formula, Since the motor power factor is given, we can obtain:

[0081] (twenty four)

[0082] And because of the motor power At the same rotational speed, we can obtain:

[0083] (25)

[0084] Therefore, the equivalent damping coefficient after the motor is connected to the rectifier bridge and then to the step-up / step-down circuit is... We can obtain:

[0085] (26)

[0086] If a different boost / buck circuit structure is used, what is the relationship between the input and output voltages? Then the formula for the equivalent damping coefficient can be:

[0087] (27)

[0088] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A vibration control method of a vibration active control system, characterized by, The vibration active control system comprises six main modules, i.e., a vibration source, a motion transmission mechanism, a PMSM permanent magnet motor, a three-phase rectifier bridge, a boost / buck circuit and a load; The vertical dynamic speed of the vibration source in the mechanical vibration structure is converted into rotary motion through the motion transmission mechanism, and then is converted into the rotational speed of the motor shaft head through the motion transmission mechanism and is input into the PMSM permanent magnet motor, the PMSM permanent magnet motor generates an induced electromotive force under the excitation of the rotational speed, the three-phase voltage signal of the induced electromotive force is converted into a direct current voltage through the rectifier bridge, and finally is loaded into the load after conversion through the boost / buck circuit; The vibration control of the mechanical vibration structure is realized by adjusting the duty cycle of the boost / buck circuit; The vibration control method comprises determining the duty cycle of the boost / buck circuit according to the vibration control degree of the mechanical vibration structure, i.e. according to the equivalent damping coefficient c e The relationship between the duty cycle D and the equivalent damping coefficient c e is as follows: In the above formula, f(D) represents a function of the relationship between the input and output voltages in the step-up / down circuit, i is the transmission ratio of the motion transmission mechanism, η is the transmission efficiency of the motion transmission mechanism, p is the number of motor pole pairs, Ψ f is the motor stator flux, r is the length of the cross arm of the motion transmission mechanism for converting vertical motion into rotary motion, R s is the stator resistance, R L is the resistance value of the load resistance, is the motor power factor.

2. The vibration control method of an active vibration control system according to claim 1, characterized by, The system further comprises a battery load or a super capacitor load to realize the recovery of vibration energy.

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