Active Vibration Control of the Flexible Rotor to Pass the First Bending Critical Speed in High Energy Density Magnetically Suspended Motor

2015 ◽  
Vol 137 (11) ◽  
Author(s):  
Enqiong Tang ◽  
Jiancheng Fang ◽  
Shiqiang Zheng ◽  
Dikai Jiang
Keyword(s):  
Critical Speed ◽  
Active Vibration Control ◽  
High Energy ◽  
High Energy Density ◽  
Flexible Rotor ◽  
Linear Quadratic ◽  
Variance Matrix ◽  
Active Vibration ◽  
Integral Controller ◽  
Optimal State Feedback

In order to minimizing the rotor displacement and the amplifier current mainly caused by the unbalance forces when the flexible rotor passes the first bending critical speed, the optimal controller is presented in this paper. The accurate modeling method for the flexible rotor based on the sine sweeping measurements is investigated. The design of the Kalman estimator and the choice of the variance matrix elements have been described. The optimal state feedback regulator with an integral controller has been used for stabilizing the system and the determination of the weight matrices has been investigated in detail. The influences of the specific elements of the weight matrices on the resonance peak of the flexible rotor when passing the first bending critical speed are analyzed. Finally, the running up test of the flexible rotor is implemented and the result shows the effectiveness of linear quadratic Gaussian (LQG) controller minimizing the rotor displacement and the amplifier current nearby the first bending critical speed. Furthermore, the comparison between the proportional-integral-differential (PID) controller with phase lead compensator and the LQG controller verifies the superiority of LQG controller in reducing the amplifier currents.

Active Vibration Control of the Flexible Rotor in High Energy Density Magnetically Suspended Motor With Mode Separation Method

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Enqiong Tang ◽  
Jiancheng Fang ◽  
Bangcheng Han
Keyword(s):  
Energy Density ◽  
Critical Speed ◽  
Active Vibration Control ◽  
High Energy ◽  
Separation Method ◽  
High Energy Density ◽  
Flexible Rotor ◽  
Mode Separation ◽  
Displacement Signal ◽  
Bending Mode

Since the mass of the rotor in high energy density magnetically suspended motor (HEDMSM) is always large and there are only three balancing planes on the flexible rotor restricted by the structure of the motor, which means that the second bending mode cannot be balanced using N + 1 planes method which is always applied to balance the flexible rotor. Then, the rotor displacements maybe large and this situation will make the system consume large amplifier currents when the rotor passes the first bending critical speed. Therefore, the mode separation method is proposed to separate the first and the second bending modes in rotor displacement and reconstruct the displacement signal nearby the first bending mode. Then, the original rotor displacement signal used by the digital controller is substituted by the reconstructed displacement signal and the amplifier current is reduced a lot when the rotor passes the first bending critical speed. Finally, the experiment of mode separation is carried out in 100 kW magnetically suspended motor and the experiment results show the effectiveness and superiority of the mode separation method in reducing the amplifier current when the rotor passes the first bending critical speed.

scholarly journals Active vibration control of the flexible high-speed rotor with magnetic bearings via phase compensation to pass critical speed

2018 ◽  
Vol 38 (2) ◽  
pp. 633-646 ◽  
Author(s):  
Shaolin Ran ◽  
Yefa Hu ◽  
Huachun Wu ◽  
Xin Cheng
Keyword(s):  
High Speed ◽  
Critical Speed ◽  
Active Vibration Control ◽  
Element Model ◽  
Compensation Method ◽  
Resonance Vibration ◽  
Flexible Rotor ◽  
Phase Compensation ◽  
Active Vibration ◽  
Micro Turbine

In modern industries, high-speed motors and generators have received great attention, and they are widely used in micro turbine, centrifugal compressor, blower, etc. However, the resonance vibration of flexible rotor will become a challenging issue when the rotor has to operate above the first bending critical speed. In this paper, a phase compensation method is proposed to improve the damping level of the flexible rotor around the first bending critical speed. The dynamic characteristics of the flexible rotor are analyzed, and the modal frequency is obtained. The rotor finite element model is verified by the modal test. Based on Proportion-Integration-Differentiation (PID) controller, the phase of the control system is shaped with different general filters to improve the damping level of the flexible rotor around the first bending critical speed. The simulation and experimental results indicate that the first bending mode damping of rotor is obviously enhanced by phase compensation. The phase compensation method can effectively suppress the resonance vibration of the rotor and make the rotor smoothly pass the first bending critical speed, achieving supercritical operation.

Piezoelectric Actuators With Active and Passive Frames

2013 ◽  
Author(s):  
Laura Tolliver ◽  
Xiaoning Jiang ◽  
Tian-Bing Xu
Keyword(s):  
Finite Element ◽  
Piezoelectric Materials ◽  
Active Vibration Control ◽  
Small Strain ◽  
High Energy ◽  
High Energy Density ◽  
Space Technology ◽  
Two Stage ◽  
Technology Applications ◽  
Passive Materials

Electromechanical actuators that generate large displacements, have large load capabilities, and demonstrate strong resonance characteristics are in great demand in the areas of precision positioning, active vibration control, and energy harvesting. Piezoelectric materials have been widely investigated for these applications because of their high energy density, quick response time, and relatively low driving voltages, but they demonstrate very small strain, typically about 0.1%. We present experimental and finite element results for two designs that use active and passive frames, respectively, to enhance the small strain in piezoelectric multilayer stacks. The first design, stacked-HYBATS, employs the synergetic contribution of d33 and d31 mode piezoelectric material. Finite element results show that this structure can generate over 50 microns of displacement and nearly 40 N of blocking force in a 36 mm × 22 mm × 10 mm footprint. The second design employs frames made from passive materials to form two stages of strain amplification in a 42 mm × 30 mm × 20 mm footprint. This two-stage design can produce over 600 microns of displacement and has a blocking force of 27 N. The active and passive materials of both designs can be varied to maximize displacement and/or blocking force. The stacked-HYBATS and the two-stage amplification system display favorable force-displacement capabilities and are promising for a variety of manufacturing and space technology applications.

Active Vibration Control of Smart Hull Structure Using Piezoelectric Composite Actuators

2008 ◽  
Vol 47-50 ◽  
pp. 137-140 ◽  
Author(s):  
Jung Woo Sohn ◽  
Seung Bok Choi
Keyword(s):  
Vibration Control ◽  
Fiber Composite ◽  
Equations Of Motion ◽  
Active Vibration Control ◽  
Piezoelectric Composite ◽  
Governing Equations ◽  
Linear Quadratic ◽  
Element Analysis ◽  
Hull Structure ◽  
Active Vibration

In this paper, active vibration control performance of the smart hull structure with Macro-Fiber Composite (MFC) is evaluated. The governing equations of motion of the hull structure with MFC actuators are derived based on the classical Donnell-Mushtari shell theory. Subsequently, modal characteristics are investigated and compared with the results obtained from finite element analysis and experiment. The governing equations of vibration control system are then established and expressed in the state space form. Linear Quadratic Gaussian (LQG) control algorithm is designed in order to effectively and actively control the imposed vibration. The controller is experimentally realized and control performances are evaluated.

A novel optimal configuration of sensor and actuator using a non-linear integer programming genetic algorithm for active vibration control

2017 ◽  
Vol 28 (15) ◽  
pp. 2074-2081 ◽  
Author(s):  
Chunyou Zhang ◽  
Lihua Wang ◽  
Xiaoqiang Wu ◽  
Weijin Gao
Keyword(s):  
Genetic Algorithm ◽  
Integer Programming ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Linear Quadratic ◽  
Linear Integer Programming ◽  
Optimal Criterion ◽  
Non Linear ◽  
Active Vibration

Due to widespread applications of a large number of flexible structures, to obtain the best dynamic control performance of a system, optimal locations of the actuators and sensors are necessary to be determined. This article proposes a novel optimal criterion for the actuators or sensors ensuring good controllability or observability of a structure, and also considering the remaining modes to control the spillover effect. Based on the proposed optimization criteria, a non-linear integer programming genetic algorithm is employed to achieve the optimal configurations. Active vibration control is investigated for a cantilever plate with the actuators in optimal positions to suppress the specified modes utilizing linear quadratic regulator controller. Several simulation results validate the efficiency and feasibility of the proposed optimal criteria.

scholarly journals Active vibration control of a flexible rotor by H.INF. control theory.

1991 ◽  
Vol 57 (533) ◽  
pp. 196-202
Author(s):  
Jan Wei WANG ◽  
Kenzo NONAMI ◽  
Mitsuji SAMPEI ◽  
Tsutomu MITA
Keyword(s):  
Control Theory ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Flexible Rotor ◽  
Active Vibration

Optimum Damping Control of the Flexible Rotor in High Energy Density Magnetically Suspended Motor

2015 ◽  
Vol 137 (8) ◽  
Author(s):  
Jiancheng Fang ◽  
Enqiong Tang ◽  
Shiqiang Zheng
Keyword(s):  
Control System ◽  
Energy Density ◽  
Critical Speed ◽  
Control Method ◽  
High Energy ◽  
Magnetic Bearing ◽  
High Energy Density ◽  
Damping Control ◽  
Bearing Force ◽  
Voltage Saturation

The rated rotational speed of the magnetically suspended motor (MSM) is always above the bending critical speed to achieve high energy density. The rotor will have a dramatic resonance when it passes the critical speed. Then, the magnetic bearing has to provide large bearing force to suppress the synchronous vibration. However, the bearing force is always limited by magnetic saturation and power amplifier voltage saturation. This paper proposed an optimum damping control method which can make effective use of the limited bearing force to minimize the synchronous vibration amplitude of the rotor nearby the critical speed. The accurate rotor model is obtained by theoretical analysis and system identification. The unbalance force response of the bending mode of the rotor is analyzed. The small gain theorem is used to determine the range of the magnitude of the control system. Then, the relationship of the optimum damping varying with the magnitude and phase of the control system nearby the critical speed is analyzed. The run-up experiments are carried out in 315 kW MSM and the results show the effectiveness and superiority of the optimum damping control method.

Sign in / Sign up

Export Citation Format

Share Document