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According to the characteristics of Fast Speed Mirror, the paper discusses that, in a FSM composite axis control system, the mechanism of the servo control, the main system performance, the speed loop of subsystem and effects of automatic zero locking system. Combined with traditional methods, a new structure of axial subsystem is proposed, to improve the rapid high-precision tracking technique. From theory to experimental model, the paper made a detailed analysis.

—– In this paper, problem faced by grid connected pv inverter is presented. Inverters connected to grid are mostly affected due to short circuit problems in the power systems. Therefore it is essential to analyze power quality disturbances in order to improve the quality of the system. Performance of inverter is affected severely by voltage sag compared to other type of power quality disturbances. Also in this paper, multilevel inverter with sag condition and without sag condition is simulated using MATLAB/SIMULINK software

Milking machine automatic control is not only an important part for dairy farm to achieve of digital management, but also one of the key development of animal husbandry. Milking machine automatic control can improve production efficiency of dairy farm and quality of raw milk. First, the need of the milking factory is known, and an automatic control requirement is developed. Secondly, an AVR microcontroller core AT90CAN128 of ATMEL, used as the centre of the controller. And then, the hardware system is designed in several modules. In the last, the software of the controller is designed in detail based on certain need. The project uses the research method of combination of experimetal research, analytical studies and lessons learned. First the paper designs the hardware circuit board and the software development of the milking machine controller. Then through debugging of the physical machine, the paper implements the function of milking automatically and cleaning automatically. The results has reached the milk production expectations, and achieved good effects.

This paper designs and implements a sliding mode observer with line-to-line trapezoidal back-EMF for brushless DC (BLDC) motor. Through the detection of three phase voltage and the current, the phase to-phase back-EMF is observed, and then the position signal and the rotor speed are estimated. The corresponding relationship between back-EMF and six rotor positions of the motor is established in this paper. With saturation function instead of sign function, the line current difference is used as the sliding surface. The whole control system employs an inner current PI loop with an outer speed PI loop. Simulation results show that the designed observer can correctly estimate the position information and speed, with strong robustness to changes of system parameters and external disturbances.

Indicating vertical in moving base to establish horizontal reference is of great significance for the near-earth autonomous navigation. Existing vertical indicating device achieves the goal by using gyro stabilized platform, but the gyroscope is difficult to maintain and has drift error. This paper proposes controllable pendulum system that is a stable closed-loop control system and similar to inverted pendulum system to accomplish the purpose. This paper covers the preliminary validation of the controllable system’s ability of indicating vertical in pulse interference cases and raises the defects of system under condition of step disturbance, by establishing mathematical model, designing double output PID controller and analyzing error , which lays the foundation for follow-up study.

The paper introduces Working mode of brushless doubly-fed machine（BDFM） and mathematical model in the d-q coordinates for BDFM，a strategy of discrete space vector modulation in direct torque control for BDFM has been Proposed 。The paper uses Matlab / Simulink to model and simulate the system of the direct torque control for brush double-fed motor based on discrete Space Vector Modulation.Simulation results prove that the discrete space vector modulation technique can reduce the torque ripple of traditional direct torque control system for BDFM, and improve waveform of current and Flux of Control winding.

In this paper, a direct ac-ac converter suitable for a variable speed wind energy conversion system is proposed. In wind energy conversion systems, due to the variation in wind speed, there will be variation in shaft speed and hence the frequency of the output will be fluctuating at the generator terminal. A direct ac-ac converter (Matrix converter) is capable of providing simultaneous control of output voltage and frequency at the generator output. In this paper the direct transfer function method is developed, to create a constant voltage and constant frequency output from a variable output voltage and frequency and the same is simulated using MATLAB/SIMULINK simulation software.

The computer virtual control method for thermostatic process of sand casting and gas forming tester system is studied in this paper. The system software is designed based on LabVIEW, which includes the design of temperature controller interface, the construction of virtual system and the design of system interface. This paper is of certain directive significance to future exploitation of virtual control system.

Fuzzy rules and its inference mechanism are the assurance of achieving feature fusion. Conventional Proportional Integral Derivative (PID) control is often used in present industrial field. Because the control parameters are fixed, the tuning results are difficult to meet the demands and the system is unstable or even out of control. This paper has a design and analysis on the dual thumb pneumatic flexible robot hand base on the active flexible bending joints we have developed. The flexible joint is composed of four elongation artificial muscles with parallel arrangement. The robot hand has five multi-actuated fingers each with three flexible joints. In this paper, Matlab is used to confirm that the fuzzy control system has good adaptability and anti-jamming capability.

This paper presents a PIR regulator using direct torque control strategy of grid connected wind turbine driven doubly fed induction generators (DFIGs) when the grid voltage is unbalanced. Under the unbalanced grid voltage condition, the stator voltage and current quality is strongly affected due to the negative and distorted components. It will be reducing the performance of other normal loads connected to the DFIG. That control scheme consisting of indirect matrix converter using DTC. To verify the value of the proposed control strategy, simulation results with 500 MVA DFIG topology are presented and discussed in the paper. Finally,the simulation studies are carried out on a 500 MVA wind-turbine driven DFIG system under unbalanced grid voltage conditions. All the results are validated by using PSCAD simulation.

Paper presents transmission nonlinearities of servodrives. These nonlinearities directly affect the performance and precision of industrial machines such as robots, manipulators, NC machine tools etc. For measuring purpose of these nonlinearities a measurement test bench was created. Presented measuring test bench is used for static and dynamic measurements of servodrives as well as for precision and gear error evaluation. Paper focuses on properties, analysis and experimental measurements of angular transmission error, torsional elasticity and repeated position accuracy.

This paper introduces the broken shaft failure problem of vacuum pump often encountered, and through the failure mechanism analysis of broken shaft in several aspects, the paper not only summarizes the cause of broken shaft vacuum pump, which is found in five main aspects of broken shaft vacuum p

Utilizing the wind power in high altitude to generate electrical power has significant meaningful while the pollution of environment of the planet is becoming worse and worse. Wireless aerial surveillance platform is very important to military surveillance, while present method costs too much. To meet the requirements mentioned above, a long-endurance multi-function floating platform is proposed in this paper. The long-endurance multi-function floating platform mainly consisted of four parts: the floating platform, the ground control base, the control box and the controller. Fuzzy-PID is used to control the movement of the rope, which connects the floating platform and the ground control base. A control strategy is made to reduce energy consumption of this system. A real system was built to demonstrate the feasibility of this paper.

The development of an intelligence control system has presently been widely studied for application in areas of automation industries, especially an electro-hydraulic system (EHS). Usually, it has the position, force and speed controls which are sensitive to change in the system parameters. Hence, a multi-input multi-output (MIMO) fuzzy controller has recently been proposed to control those parameters in a complex system. However, a mathematical model of the EHS which included the dynamic parameters has not yet been clarified. The objective of this paper is to analyze numerically the dynamic characteristics of the directional control valve (DCV) and also the flow behaviors in the electro-hydraulic system control. The spool displacements of 4/3 hydraulic closed center DCV and flow-pressure coefficient were simulated with the computational fluid dynamics (CFD). Furthermore, this paper presents CFD results, which explain the flow behaviors related with the dynamic characteristics of flow-pressure coefficient. The simulation results show that those coefficients show non-linear correlation with the opening spool displacements.

Nowadays, the level of mechanization is gradually increasing. In order to promote the rapid development of the mechanized production in China, the automatic control of large-scale machinery is required. Therefore, this paper puts forward a control model for the large-scale mechanical arm angle. During the control, the angle of the large-scale mechanical arm was calculated based on the actual production so as to achieve the automatic control of the angle. The experimental results indicated that carrying out automatic control of the large-scale mechanical arm according to algorithm proposed in this paper could improve the accuracy of the automatic control.

According to auto-incasing equipment characteristic and control demand, a kind of salt in-bags incasing control management system was designed. The paper introduced the key technologies realization of the system. In the paper, a new fuzzy controller was designed to build a dual closed-loop fuzzy control system, realizing incasing goal site error on-line continuous correction. A logistics management module based on e-Tag was designed to realize product information traceable management. The experimental results show the system realizes accurate position control and RFID logistics management with high reliability and high control precision. The system can be popularized to other products packaging industry.

The mathematical model of convert steelmaking end point prediction model based on RBF(Radical Basis Function) is presented in this paper. According to the end point prediction problem of the converter steelmaking production prediction problem, we establish the forecast model of converter steelmaking process which describes the relationship between variables such as hot metal quality, oxygen blowing, the quality of the cooling agent and additives etc. and the end point molten steel temperature and carbon content. The prediction system is multidimensional and nonlinear. The model between variables and the target is unknown. For this situation, this paper applies RBF neural network to forecast target, establishing the prediction model based on RBF neural network. So as to obtain the variables and the mathematical model between steel endpoint temperature and carbon content.

On the basis of the analysis of the difficulties in the meteorological measurement, this paper proposes a three resistance measurement method based on the self-correcting technique, through comparing the relative size of the three groups of measuring signal for the desired measuring value. The advantage of this method is to counteract the effects of drift in the measurement circuit, which can achieve high precision results in the bad external environment. This paper gives a comparison of measured data. The method has been verified in practical application.

The double-fed control strategy for AC hoist motor is discussed in this paper. The AC/DC/AC power converter is adopted as main circuit. Three-phase neutral-point-clamped three-level rectifier is used as AC/DC link to realize unity power factor at grid-side, which reduces harmonic distortions. For the DC/AC inverter, three-level topology is used, which is controlled by stator-flux oriented vector control method. Meanwhile, energy flows in bidirectional way by back to back three-level power converter. The hoist motor control system obtains a high dynamic performance when stator side operating in unity power factor condition. The reliability and safety of hoist system is improved based on double PLC. The control system mentioned in this paper is being used to control a shaft hoist with a capacity of 260kW, and the power saving is remarkable.

The paper design a double eccentric mass driven spherical robot, the ball is also subject to eccentric force and inertia force that generate by internal drive units in movement. Due to the unique spherical shell, the robot in the dynamic state transition process, Friction cannot offset the robot motion state change due to internal driving motion error of small units. In order to make linear movement of the spherical robot that can smooth start, stop and speed control, the paper design a method for linear motion driven spherical robot with double eccentric mass control. The improved driving eccentric mass of robot total mass ratio is larger, that can provide the eccentric torque and inertia moment more, the robot has higher motion velocity.

This paper conducts a comprehensive study on the optimization design for luffing mechanism of portal slewing crane. First, displacement formulae are derived of crampon hinge point of the luffing mechanism. Secondly, mathematical model is established for luffing mechanism optimization design of portal slewing crane, according to the mechanism characteristics, and, with an aim of making crampon hinge end point to move horizontally, and of satisfying the value of maximum and minimum amplitude, and of saving material, etc. Finally, program of optimization design is compiled for the luffing mechanism of portal slewing crane. The luffing mechanism of M4022 portal slewing crane is optimized, and the optimization result is satisfactory. This paper makes it possible to obtain not only each rod length and cross-section area, but also obtain the counterbalance weight and the each rod maximum force of the luffing mechanism.

The objective of the present paper is a numerical analysis of the transient flow through a 4/3 hydraulic closed center direction control valve. The real-time discharge coefficients corresponding to supply flow difference have been considered. In order to develop an intelligent control system for an electro-hydraulic system (EHS), a new controller has recently been proposed to control those parameters in a complex system. However, a mathematical model of the EHS including the transient parameters has not been clarified. The main objective of this paper is to numerically analyze the dynamic characteristics of the directional control valve and also the flow behaviors in the electro-hydraulic system control. Both the steady state and transient flow though the valve which affect to flow-pressure coefficient were numerically considered. Moreover, this paper presents numerical results, which explain the flow behaviors related with the real-time pressure drop and discharge coefficient. Both a high inlet flow and a large opening spool have determined the pressure drop increment.

In this paper, a model predictive controller for the position tracking of flexible robot joints with harmonic drive gears is presented. The control methodology enables the drive's safety and physical constraints on torque and speed variables while guaranteeing the stability of the system. The effect of the predictive horizon on the drive performance is examined. Moreover, the influence of parameter changes is tested in this paper. Experimental results demonstrate the proposed controller is very effective in tracking position references while meeting the demanding drive constraints requirements during operation.

This paper presents a new approach for reducing energy consumption coupled with force and position controls in the electro-hydraulic systems (EHS). The EHS inverter will be added for control to vary the speed of electric motor driven hydraulic pump. In addition, a single directional control valve is used to control the system parameters, which cause loss of energy. The main objective of this research is to numerically analyze the energy loss in the new control approach in the EHS with the inverter by using a simple directional control valve. The spool displacements of 4/3 hydraulic closed center directional control valve, transient flow-pressure coefficient and energy loss were simulated with computational fluid dynamics (CFD). In addition, this paper presents CFD results. The relationships of flow rate variables with time-dependent pressure drop and energy loss were addressed. The flow behaviors related with transient flow-pressure coefficients were also discussed. It is found that the loss of energy increases, depending on both the large opening spool displacement and the inlet flow variable.

This paper focuses on the recent advancements made in hydraulic motor. Various parameters of hydraulic motors are studied and their performance with respect to the parameters is studied. nonlinear dynamics model, Gear motor, swash plate motor, radial piston hydraulic motor etc have been examined. Fault diagnosis, dynamic vibration, frictional analysis and speed variation are some of the issues which are being discussed in the paper. The performance results showed that the amplitude of vibration increased with the increase of output torque of the water hydraulic motor and the hydraulic motor with planetary gear train has the advantages of large unit volume displacement and small flow rate fluctuation ratio. Some measures were proposed to improve the low-speed stability of the hydraulic motor. Keywords-hydraulic motor, nonlinear dynamics, hydraulic spring

To improve the tracking capability of the PV, soft computing technique is used to utilize the PV power effectively. Here, DPSO is used to maximize the PV power. In this paper Performance of SEPIC converter compared with buck-boost converter under both normal and partial shading conditions of PV system. This paper gives the new intelligent control technique in order to track the global maxima of PV power effectively and also gives MATLAB-Simulink to control the system parameters via DPSO method.

This paper deals with the design and evaluation of robust excitation controller for a single-machine infinite-bus power system. The design of the regulator guarantees the stability of the closed loop system and ensures the output voltage is maintained within an acceptable threshold. In addition, it damps out local mode oscillations for small signal disturbances. The designed robust controller is also analyzed under change in step input and disturbance, which limits the heavy oscillations on the speed ω and voltage. Glover-McFarlane loop shaping algorithm is applied in designing the robust excitation controller. Two different techniques such as Optimal control and mixed sensitivity approach is used in this paper. The performance of the AVR was analyzed and compared with IEEE type2 Exciter.

With the deregulation of electricity markets, the system operation strategies have changed in recent years. The systems are operated with smaller margins. How to maintain the voltage stability of the power systems have become an important issue.This paper presents an Artificial Feed Forward Neural Network (FFNN) approach for the assessment of power system voltage stability. This paper uses some input feature sets using real power, reactive power, voltage magnitude and phase angle to train the neural network (NN). The target output for each input pattern is obtained by computing the distance to voltage collapse from the current system operating point using a continuation power flow type algorithm. This paper compared different input feature sets and showed that reactive power and the phase angle are the best predictors of voltage stability margin. Further, the paper shows that the proposed ANN based method can successfully estimate the voltage stability margin not only under normal operation but also under N-1 contingency situations. The proposed method has been applied to the IEEE 14 and IEEE 30 bus test system. The continuation power flow technique run with PSAT and the proposed method is implemented in MATLAB.

This paper proposes a design of Specification Oriented Compensator (SOC) with a Proportional Integral Derivative (PID) controller for Load frequency Control (LFC) in a thermal power system. The phase margin which is derived from the computationally tuned response of PID controller is considered as a desirable specification and it is used to design the compensator. The different structures of compensator like lead, lag and lead-lag were first simulated in a single area power system and better results are found in Specification Oriented Lead Compensator (SOLC). The simulation study of two area thermal power system with SOLC is then performed and their frequency deviation and tie-line power deviation characteristics are compared with conventional PID controller, Integral controller and also with a non controller system. The Integral Absolute Error (IAE) and Integration Time Absolute Error (ITAE) are considered as performance indices to scrutinize the system robustness. The simulation studies clearly reveal the superiority of the proposed SOLC with PID controller over others in way of enhanced system transient response, improved the stability and robustness of the system. All the simulations in this paper are performed using Matlab software.

This paper proposes a technique for the identification of defects of three-phase squirrel cage induction motors. Simulations were performed using ANSYS finite element software package to obtain the flux density waveform in the air gap. Broken rotor bar fault was simulated by breaking rotor bars to see how the flux density is affected. In this paper, a new approach for the identification of broken rotor bar based on the calculation of high-frequency losses in induction motors is presented. The approach presented in this paper requires little time for loss calculation and fault identification.

Nowadays the number of non linear loads in power systems is increasing dramatically. These non linear loads inject harmonic currents and voltage which makes the supply currents non-sinusoidal. These harmonics are eliminated via an active power filter. The reference currents are generated by shunt active filter which is provided to compensate harmonic currents demanded by the load. Different current control strategies are implemented to improve the performance of shunt active power filter. These techniques are useful in making the supply currents sinusoidal. The performance of the current control techniques are different from each other. The %THD can be reduced with the aid of shunt active power filter. In this paper, different current control schemes are analyzed and their outputs are compared to determine the effectiveness. The most effective current controller generates less %THD. The power quality of the system is improved with the reduction of %THD. The different current controllers which are compared in this paper are GA controller and PI-VPI controller.Under analysis, the PI-VPI controller is found to be effective.

Considering the probabilistic of the wind power and the solar power, a fault recovery method for distribution systems with the wind power and the solar power is presented in this paper. For the wind power, a simplified steady-state equivalent model of an asynchronous wind generator is added into the Jacobian matrix to consider the impact of the wind power on systems. For the solar power, its output is considered as an injected power which is related with solar irradiance. Three-point estimate is employed to solve the probabilistic power flow of distribution systems with the wind power and the solar power. The restoration is described as a multi-objective problem with the mean of the system loss and the number of switch operations. Fast elitist non-dominated sorting partheno-genetic algorithm is used to solve this multi-objective problem. IEEE 33-bus system is used as an example and the results show that the models and algorithms in this paper are efficient.

In this paper, a solution for the control of a distributed parameter process, using a neural distributed parameter controller is presented. The main originality elements from the paper are the introducing of the distributed parameter controller concept, respectively the including of this type of controller in a control structure. In the paper, a method for tuning a distributed parameter controller is presented, taken as example the pH control system associated to a blunting process. Also, due to the complex structure of the controller two neural networks are used for its implementation. In order to highlight the main advantages of using of this type of controllers, some representative simulation results are presented.

Taking the lower arm of DK7725 WEDM Taper Machine as the research object, this paper uses the ANSYS Workbench collaborative simulation environment to analyze equivalent stress and deformation of the lower arm in the different working conditions, find the weak part of Lower Arm, analyze static structure of the lower arm, and improve lightweight design. According to the characteristics of Taper Machine overall structure and optimization variables, using the Design of Experiments (DOE) method, this paper combines the response surface method (RS), goal driven optimization method (GDO) with multi objective genetic algorithm optimization method (MOGA) with the candidate schemes, extractes candidates from the calculation program, insert the candidates as the design points into the whole optimization calculation. By controlling parameter allowable error, this experiments obtains the best optimal solution. The results show that if the mass of the lower arm is decreased 13.28%, the lower arm has stable dynamic performance,and get good optimization effect.

The static balancing of the weight forces of any mechanical system which is not working in horizontal plane is considered in order to decrease the acting power. From practical point of view two main ways of balancing could be taken into consideration: by mass redistribution of components and/or by adding counterweights, and by elastic forces of the springs or of the gases.The first solution is not always possible due to the clearance diagram of mechanical systems and due to increasing of the dynamic stresses of components. Second solution is more and more used to various mechanical systems and many constructive solutions were proposed in last time. The complexity of balancing systems with springs comes from the need of using zero-free length springs.In any case the mathematical model has not a unique solution. Present paper is continuing a former paper of author and is presenting a method to find the optimum solution of the simplest elastic system which is using a real spring. Design variables are the position of spring’s joints, as well as the constructional parameters of a real spring.

A novel boost converter named tri-state boost converter is introduced in this paper. According to the operation principle of the tri-state boost converter, the Euler-Lagrange model is set up. Based on the passivity-based control theory and Euler-Lagrange model, a passivity-based controller of the tri-state boost converter is designed. By damping injecting, the input current and output voltage of the tri-state boost converter can reach the desired equilibrium values rapidly. The speed of the tri-state boost converter to reach the desired equilibrium values varies when the damping values changes. The controller is simple to design and makes the tri-state boost converter having better dynamic and steady performances. The passivity-based controller proposed in the paper is proved feasible by simulation results.

This paper presents the operational principle, architecture design, resonance characteristics and FEM simulation of a new fully decoupled dual-mass silicon micro-gyroscope. The drive motion and sense motion of the micro-gyroscope studied in this paper are isolated from each other, mechanical quadrature error is thus dramatically suppressed due to the minimizing of undesired coupling between the drive and sense modes. Moreover,two identical single-mass gyroscopes are adopted and coupled with coupling beams to form a dual-mass micro-gyroscope, which provides enhanced common mode rejection in a differential mode. Finally, modal and harmonic analyses are implemented by FEM software, the simulation results obtained verify the good properties of the novel micro-gyroscope.

This paper presented a magnetic pendulum to scavenge the human kinetic energy from arm motion and convert the kinetic energy to electrical energy for portable electronic devices. The harvester mainly consisted of a stator, a rotor and a control circuit. The stator was set of electric coils while the rotor is an eccentric mass made of permanent magnet. A torsion spring was also added onto the rotor such that the motions in both horizontal and vertical directions can be effectively harvested. The energy harvester could be worn on human arm. When the arm was in motion, the device would then generate power. The paper presented a detailed kinematical analysis and power conversion analysis. As a typical case, the device was 40 mm in diameter and 50 g in weight, the simulation showed that when worn on wrist, it could generate about 30 mW during normal walking.

The capacitor voltage balance of the sub-module is the necessary condition for normal operation of the STATCOM. In this paper, the topology and mathematical model of the STATCOM are introduced briefly, the instantaneous power characteristic and capacitor voltage balance principle are studied in detailed, and the balance control algorithm for real project is put forward, in this algorithm, the modified reference wave is got by delay the phase modulation wave by 90°, rather than calculate the sine value of the PLL phase. So the algorithm in this paper can realize in sub-module in real project, the simulation result and real project validated its efficient.

Steady-state magnetic field Superconducting magnets power supply with double inverse star thyristor rectifier technology solutions, is a typical non-linear loads, will bring great reactive power impact and harmonic pollution at runtime. This paper according to the scheme of scientific facility chain type high voltage active power filter (APF), combined with the non-linear characteristics of the active filter system and proposed a current inner-loop decoupling method using fractional order PI controller instead of ordinary PI controller. Based on the improved Oustaloup algorithm, the solution of fractional order calculus is realized. Finally, the working effect of fractional order PI controller and ordinary PI controller are comparative analysis through simulation and experimental results, the results show that: fractional order current inner-loop PI controller used in this paper is correct, and has a certain reference value.

The diode uncontrolled rectifier or the phase controlled rectifier is widely used in conventional rectifier link, thus the conventional rectifier link on the grid inject a large number of harmonics and reactive power, and they cause a severe grid “pollution”. This paper starts from the basic principles of the PWM rectifier, then the paper discusses the topological classification of three-phase PWM rectifier in detail. Based on topological structure, the paper builds the mathematical model of three-phase stationary coordinate system and two-phase rotating coordinate system. Based on space voltage vector, the paper studies PWM control method in-depth and simulates in Matlab/Simulink. The correctness of the theoretical study of three-phase voltage source PWM rectifier system is verified by the simulation results.

Metamorphic mechanism would result in impact when it was changing from one configuration to the next. As a result, the internal impact force would bring about great vibration for the mechanism. What was more, it would make the mechanism be unstable. Therefore, the internal impact for metamorphic mechanism was expected to be analyzed. The controllable metamorphic palletizing robot mechanism was investigated in this paper. First of all, its kinetic characteristic was analyzed. In addition, the total momentum of the link which suffered impact was calculated. Furthermore, the impact force of the link was known. Finally, the relationship between the impact time when the mechanism was changing configuration and the momentum of the link was described through example study. The work of this paper provides some references for stability study of metamorphic mechanism.

In this paper, building a systematic equation of mathematical model and dynamic variation based on the movement of object falling into water based on the breach parabolic by virtue of the combined means of boundary layer theory and differential equation with the help of computer simulation, this paper further illustrates the features of physical characteristics and its dynamic movement process, which provides a sort of accurate and credible analytical thinking for the similar engineering calculation.

This paper studies the application of Halbach array in optimal design of Permanent Magnet Synchronous Motors (PMSM). First, the paper demonstrates the intrinsic sinusoidal magnetic field and one-side magnetic shielding effect produced by Halbach array in FEM. Afterward, a serious of Halbach motor models based on different segment numbers per pole are established combined with Ansoft. Next, the waveform and harmonic contents of air-gap flux density are analysed. Then, the relationship between the segment numbers per pole and cogging torque are explored. Finally, the power-angle curves for coreless/core rotors are contrasted. The above results explain why and how Halbach array can be applied in PMSM design to reduce harmonic components for air-gap flux density, increase power density and decrease moment of inertia.

The effects of total voltage level number (TVLN) on behaviors of the modular multilevel converter (MMC) are analyzed in this paper. First, it gives a brief introduction on the MMC system for how the converter generates multilevel staircase waveform. Second, the operation characteristics during the start process are analyzed. The capacitor voltage of a SM, the DC voltage, the exchanging power, and the DC loop current would be all influenced by different TVLNs. Third, the harmonic components in steady state are discussed to reveal the reason why the total harmonic distortion (THD) of the output voltage of MMC reduces when the TVLN increases. Simulation results show the validation of the conclusions drawn in this paper. Furthermore, when the TVLN is small, the THD in SUPWM method is lowest. However, when the TVLN increases, especially greater than 11, the THD in CPS-SPWM method is lowest.

PWM rectification system with fixed parameter PI can not meet the situation of mutational load and changing from energy feedback status to controlled rectification status. In the PWM rectification system traditionally basing on voltage oriented vector control, traditional voltage loop PI controller was replaced by PI adaptive controller with combination of single neuron and expert system. It is a good solution to the problem. In this paper a simulation model of controlled rectification system in the platform of Matlab/Simulink was established. It appled the S function and get the PI regulation with combination of single neuron and expert system. At last, the paper get the comparison of the simulation results before and after the improvement when load changed and status transformed. The results showed that system of the PI adaptive controller has the faster reaction speed and better robustness. It verified the validity and feasibility of the method.

Because of the nonlinear motion of the robot-fish and the uncertain water waves, it is difficult to track dynamic target accurately and quickly for the robot-fish. To solve this problem, this paper proposed the target tracking strategy of underwater robot-fish based on Unscented Kalman filter (UKF). UKF is a nonlinear filtering on the basis of unscented transformation, which consists of prediction and update recursively, thus estimate the state of the system. To avoid the particle degeneracy, this paper selects sigma points adopting scale symmetric sampling strategy. We apply UKF method to the underwater robot-fish competition in China. Simulations show that the Robot-fish has fast tracking speed, shorter tracking path and smaller tracking error using UKF method than not using the method. It has excellent tracking performance.

The SVPWM technique plays an important role in the DC-AC transform. The modeling and simulation for SVPWM were proposed in this paper. The sector calculating model and basic vector working time model were set up. The effective vector function of time was set up. The triangle wave symmetry modulation was established too. The simulation results show that the model proposed in this paper is effective and has application value.

This paper presents the research findings of identification method for LPV models with two scheduling variables using transition test. The LPV model is parameterized as blended linear models, which is also called as multi-model structure. Linear weighting functions are used as the local model weights and the Gauss-Newton method is used to optimize the nonlinear LPV model parameters. Usefulness of the method is verified by modeling a high purity distillation column, the case study shows that the multi-model LPV models can yield a better model accuracy with respect to simulation outputs. The identification method proposed in this paper can be used in batch process identification.

Many researchers dealt with single fault but in real life situations, combined action of two or more single faults are usually present. Multi-faults (two and three combinations) were studied by few researchers. Researchers have mostly studied the vibration behavior of a rotor with misalignment, unbalance and rub separately. This paper presents one such case, where multiple faults are considered together in a rotor system, i.e. misalignment, unbalance and rub. The objective of this paper is to experimentally investigate the vibration response of combined of three faults misalignment, unbalance and rub using Fast Fourier Transform (FFT). FFT spectrum of combination of three faults misalignment, unbalance and rub show 1 X and 2 X are predominant and many sub harmonics are generated.1X peak represent unbalance, 2X peak represents misalignment and sub harmonics shows rub fault.