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Aim to the problem of engine fault diagnostic accuracy, research an engine fault diagnosis technologies based on adaptive neuro-fuzzy inference system. The method is proposed that using known input and output data, construct a fuzzy inference system, internal systems adjust the membership function using a least squares method based on hybrid learning algorithm and reverse the spread of the combination...
At present, the integrated navigation system used by multirotor Unmanned Aerial Vehicles (UAVs) is heavily dependent on the GPS when flying outdoors. However, signal block, interference and other factors will lead to the GPS failure, in which case the UAVs' navigation error will quickly diverge. In this paper, an aerodynamic model / INS (Inertial Navigation System) / GPS failure-tolerant navigation...
Motor drive operation mechanism of High-Voltage Circuit Breaker(HVCB) need permanent magnet synchronous motor(PMSM) with high-dynamic response. Reducing the rotor inertia of PMSM is one technique to realize high dynamic response of the motor. By digging holes in the rotor, the inertia can be reduced. The influence of shape, position and size of inertia-reducing holes on the performance of PMSM is...
This paper first analyzes the mechanism of vibration noise and torque ripple of the switched reluctance motor, and then studies methods of reducing torque ripple and noise reduction according to the principle. In order to reduce the noise, two-step phase conduction is proposed when motor starts. Meanwhile, each phase of the shutoff in advance will be replaced by reducing duty ratio slowly. In order...
An adaptive HOSMC (higher order sliding mode control) scheme is proposed to achieve maximum power point tracking of DFIG wind turbine system. DFIG power generation system is firstly established. Adaptive second order SM (sliding mode) rotor voltage controller is then presented to track maximum wind energy and adjust reactive power. Finally, the system simulation is executed under random wind speed...
Conventional model-predictive control (MPC) achieves good steady-state performance and quick dynamic response. However, a lot of calculations are needed when deciding the best voltage and objective function selected process needs time-consuming tuning work. To solve these problems. In this paper, the objective function of predictive control is analyzed for asynchronous AC motor. By means of mathematical...
In this paper, the signal processing scheme of high frequency (HF) signal injected sensorless control scheme of Permanent Magnet Synchronous Motor (PMSM) at low speed is discussed. First, a new modulation strategy based on Short-time Fourier Transform (STFT) and a special apart reference frame is presented, which is capable of processing signal effectively and estimating the position and speed of...
In this paper, consider the effect of the load inertia fluctuation for surface-mounted permanent magnet synchronous motor (SPMSM), the problem of dynamic response of SPMSM is studied. A backstepping control algorithm based on disturbance observer (DO) is proposed. Firstly, according to the equation of motor speed, the minimum-order observer is established to observe the disturbance value of load inertia,...
With the vigorous development of new energy sources, wind power generation technology has been developed rapidly. Due to the reverse distribution of wind energy resources and load centers, large-scale wind power transmission is inevitable. Using series capacitor compensation technology is an effective measure to complete large-scale wind power transmission, but may induce sub-synchronous oscillation...
In order to realize the high dynamic performance of induction motor, a passive speed control scheme of induction motor based on full-order state observer and speed adaptive estimation is proposed for the non-linear nature of the motor. With the analysis of the passive of induction motor and the relationship between passive and stability, a scheme of asymptotic stability torque tracking controller...
Based on double PWM structure, this paper analyzes the energy relationship between each part of the system according to the system energy flow in balanced energy state and unbalanced energy state and builds the energy mathematic model of double PWM. In order to solve the problems of DC bus voltage fluctuation and the mismatch in system output power and the motor power caused by the imbalance between...
Based on the rolling process data from practical engineering, a thermal damage mitigating model of domestic 300MW steam turbine unit is established, which includes power model of steam turbine and thermal damage model. In order to get the theoretical minimum variance, the coefficient matrix of this mitigating model is decomposed. Furthermore, an assessment for the PI control practice of steam turbine...
The failure rate of rotor bars is high, which causes large area of broken conducting bars, shortening the lifetime of motors. Therefore, the diagnosis of broken rotor fault diagnosis is of great importance. First, the mathematical model of induction motors is presented, and the internal and external magnetic field boundary conditions are defined. Second, frequency domain analysis method is combined...
Engineering often requires magnetic bearings with sufficient capacity and to reduce the volume as much as possible at the same time. In this paper, the design principles of air gap, magnetic pole, rotor, stator, magnetic pole area and coils are given on the basis of practical engineering experience. Radial magnetic bearing structure with different shaft diameters and different magnetic poles number...
This paper presents a singularity-free controller for 3-D path following of model-scaled autonomous helicopters. The reference path is expressed by a parameterized regular curve. The system is stratified as the inner-outer loop. Each loop is designed independently based on time-scale separation principle. During the outer position loop, the controller is constructed with saturation function to realize...
In this paper, quadrotor with air drag is locally asymptotically stabilized by using controlled Lagrangians method. Three linear subsystems are got by conducting input transformations, linearization at the desired equilibrium, and invertible state transformations to dynamical model of quadrotor. Then subsystem with two under-actuation degrees is asymptotically stabilized by utilizing controlled Lagrangians...
In order to control the altitude of the quadrotor aircraft, an altitude control algorithm was proposed. Firstly, on the basis of analyzing the principle of quadrotor flight, a mathematical model of quadrotor was established. Secondly, feedforward control link and transition process link were arranged to PID feedback controller to enhance the control performance and altitude control precision of the...
Switched reluctance motors (SRM) have many differences between traditional motors in performance analysis because of the special structure. First, the characteristics and structure parameters with large influence on the performance of SRM is discussed. Then a method for modeling and simulation of SRM system based on Maxwell and Simplorer is proposed. Finite element model of SRM with different structure...
To achieve automatic generation control (AGC), the constant active power control is required for wind turbine generators (WTG). The accurate estimation of available wind power (AWP) is a prerequisite for WTGs to effectively participate in AGC and enhance the performance of AGC. In such a case, the maximum power point tracking (MPPT) control is not adopted and accordingly the MPPT principle cannot...
In order to achieve the maximum power extraction below its rated value, wind turbine is generally controlled by maximum power point tracking (MPPT) strategies. However, due to the large inertia of wind turbines, it is difficult to adjust the rotor speed according to the highly fluctuant wind speed accurately and quickly. Consequently, the efficiency of wind energy extraction will not reach its theoretical...
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