A simple polymerization control method for the air conditioning cluster

This study presents two improved designs of eccentric-shaped permanent magnets and teeth-shaped stators in radial-flux dual three-phase permanent magnet electric machines to reduce cogging torque and torque ripple. The finite element analysis (ANSYS Electromagnetics) has been adopted in simulation, and real radial-flux dual three-phase permanent magnet electric machines have been fabricated in experiment to verify the study. Using the radial-flux dual three-phase permanent magnet electric machines in electric machine systems can improve the reliability and obtain higher output torque. In electrical drives and control, a simplified model-free predictive current control method has been proposed and implemented to drive the radial-flux dual three-phase permanent magnet electric machines, and the control law has been achieved by a TMS320F28377S microcontroller of Texas Instruments. The simplified model-free predictive current control method is senseless to parameter variations and back electromotive force of the permanent magnet electric machines, and only needs current sensors to detect six-phase current. The optimal one has been chosen by 14 various switching modes, which has the minimum cost function, and then the converter can be directly driven and controlled in the next sampling period. The features of the simplified model-free predictive current control method can reduce the algorithm calculation and avoid the defect of conventional model-based predictive current control scheme. A proportional-integral speed controller has also been designed to achieve the speed response of the fixed-speed tracking effect. Finally, the feasibility and effectiveness of the proposed simplified model-free predictive current control method for the dual three-phase permanent magnet electric machines can be verified in the experimental and quantitative results.

This paper presents a novel simplified digital control method for active power filters. By forcing the mains current to be linear with the mains voltage, the functions of harmonics elimination, reactive power compensation and unbalance correction are realized. In the proposed control method, only the mains currents and the dc bus voltage of the inverter are required to be detected. And with simple calculation, the duty ratios of switches in each switching cycle are got. So the fully digital control is easy to realize, the complex calculation in the conventional instantaneous reactive power theory is avoided and the difficulty in realizing digital control caused by the hysteresis is overcome. The viability and effectiveness of the proposed control method is demonstrated by simulation and experimental results.

This paper presents a simple and effective control method to control the output voltage of DC-DC converters. The proposed method overcomes the problems associated with PWM hysteresis control. The method is also simpler and easier to implement than one cycle control (OCC). Boost, buck-boost, buck and cuk converters are selected for study. Two cases of study are included. The first represents disturbances that nay occur in the converter input voltage while the second represents the change in the converter output reference voltage. Simulation results validate the effectiveness of applying the proposed method to DC-DC converters.

One of the simplest and most popular methods to design a model-based controller for a nonlinear dynamic system is to apply linear control theories to the linearized model of the nonlinear system. For linearization, first-order Taylor series expansion is a straightforward and widely used method. Although the related linearization method is fairly simple, unfortunately, it causes an error in the linearized model, especially in highly nonlinear systems. Different strategies have been proposed to increase the robustness of linearization-based control methods against the linearization error. All of the methods somehow look at the linearization error as uncertainty or disturbance, which has to be rejected. Generally speaking, the lack of the linearization technique reduces the quality of control. One area in which quality and simplicity of control can be necessary is spacecraft attitude control. For the purpose of spacecraft attitude control, this paper improves a well-known trajectory linearization control (TLC) method as a simple and practical nonlinear trajectory tracking control method using an error-less, fine linearization technique. The modified TLC is then used to develop a control law for spacecraft attitude control with only three tunable control parameters and an approximation of the spacecraft inertia matrix. Finally, due to the elimination of uncertainty caused by the linearization error, in a simple way, the novel attitude controller leads to better performance in comparison with the traditional method. The superiority of the new approach is illustrated in numerical simulations.

The mutual impacts between adjacent buildings caused large-scale damage during past major earthquakes sparking interest in examining the reliability and effectiveness of various control devices for alleviating the seismic responses of adjacent buildings. In this study, seismic response attenuation of multi-story adjacent buildings connected with MR dampers is examined using the Simple Adaptive Control (SAC) method. The use of the adaptive controller is advantageous as it can cope with the structural characteristics change during the severe events such as earthquakes. The simple Bouc-Wen model is considered in the analysis to model the highly nonlinear behavior of the MR damper. The Linear Quadratic Regulator (LQR) is used to design the reference model with desired trajectories. The change in the structural characteristics is reflected as a reduction in the plant's mass and stiffness as a result of the damage in the structural system. The efficacy of the simple adaptive controller is investigated in the presence of damage and in case where the system still undamaged. The results show that connecting adjacent buildings with MR dampers driven by the Simple Adaptive Control method is quite effective in mitigating the seismic responses.

This paper presents a simplified active disturbance rejection control (ADRC) method for implementing the DC capacitor voltage in Z-source constant. Active disturbance rejection control method is the development of PID control. It is suit ab le for the inverter with variable input. A simplified ADRC method is used in this paper to reject the disturbance from variable input in Z-source inverter. In its ESO module part, Kalman filter is used to estimate the state and the disturbance, which can approach the true value at the extreme, and reduce the computation time. The simulation result shows the control method can achieve the control requirement satisfactory.

This paper proposes a simplified vector control method with output capacitor voltage balance for voltage oriented control of the three-level three-switch Vienna rectifier. The proposed control method makes use of a single carrier based pulse width modulated (PWM) switching technique instead of complex space vector method for the Vienna rectifier. The vector control method is comprehensively compared with the existing hysteresis control method in terms of transient response and input current total harmonic distortion (THD). This method is implemented to control the converter for wide range of load and unbalanced grid supply voltage conditions. A 1 kW prototype of the converter is built and tested in the laboratory environment using the proposed vector control method and compared with the conventional hysteresis control method. The proposed control method provides unity power factor operation with sinusoidal input currents at the input side and balanced output capacitor voltages at the output side.

This paper proposes a novel and simple control method for an active power quality compensator (APQC) used in electrified railways. The proposed method consists of only constant do capacitor voltage control, which is generally used in APQCs. No detection method for harmonic, reactive and negative-sequence components is necessary. Thus we offer the simplest way to compensate the harmonic, reactive and negative-sequence currents on the primary side of the Scott transformer in the traction substation. The basic principle of the proposed control method is discussed in detail, and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents with unity power factor are obtained on the primary side with the proposed control method, which uses only constant do capacitor voltage control.

Stepper motors are employed in a wide range of consumer and industrial applications. Their use is simple: a digital device generates pulse-bursts and a direction bit towards a power driver that produces the 2-phase currents feeding the motor windings. Despite its simplicity, this open-loop approach fails if the torque load exceeds the motor capacity, so the motor and driver should be oversized at the expense of efficiency and cost. Field-Oriented closed-loop Control (FOC) solves the problem, and the recent availability of low cost electronics devices like Digital Signal Processors, Field Programmable Gate Arrays (FPGA), or even Microcontrollers with dedicated peripherals, fostered the investigation and implementation of several variants of the FOC method. In this paper, a simple and economic FOC torque control method for hybrid stepper motors is presented. The load angle is corrected accordingly to the actual shaft position through pulse-bursts and direction commands issued towards a commercial stepper driver, which manages the 2-phase winding currents. Thanks to the FPGA implementation, the control loop updates the electrical position every 50 μs only, thus allowing a load angle accuracy of −1/100 rad for a rotor velocity up to 750 rev/min, as shown in the reported experiments.

A simple and sensitive quality control method of the anaerobic atmosphere for identification and antimicrobial susceptibility testing of anaerobic bacteria

The general model predictive current control uses a discrete-time model of the system to predict the future current behavior for all the possible voltage vectors generated by the inverter, and then the vector which minimizes a cost function is selected and applied. In this paper, a simplified model predictive current control method for a three-phase voltage-source inverter is presented in order to reduce the amount of calculations in the practical implementation of this method, especially for multilevel ones with large predictions. Utilizing the sector information of the reference voltage space vector, the proposed method just needs a subset of all the available voltage vectors for the prediction and optimization. The computational effort has been greatly reduced while the steady-state performance and dynamic response of the current control are improved. In addition, a reduced switching frequency is obtained. Simulation results are presented to verify the proposed method.

In this paper a simplified and stable high frequency injection sensorless control method for reluctance synchronous machine drives is presented. This method is based on previous work where the conventional band pass filter is omitted from the demodulation scheme to prevent unnecessary time delay and magnitude decrease. Previous work presented accurate position estimation at very low speed under no-load conditions. The proposed method is evaluated under various different load conditions and at high speeds. The performance of the proposed method is compared to the performance of the drive while using a rotary encoder. Experimental results show that the scheme is stable under various load conditions and delivers good performance. (6 pages)

The increase of the switching speed in power semiconductors leads to converters with better efficiency and high power density. On the other hand, fast switching generates some consequences like overshoots and higher switching transient, which provoke electromagnetic interference (EMI). This paper proposes a new closed-loop gate driver to improve switching trajectory in insulated gate bipolar transistors (IGBTs) at the hard switching condition. The proposed closed-loop gate driver is based on an active gate voltage control method, which deals with emitter voltage (VEe) for controlling diC/dt and gets feedback from the output voltage (vCE) in order to control dvCE/dt. The sampled voltage signals modify the profile of the applied gate voltage (vgg). As a result, the desired gate driver (GD) improves the switching transients with minimum switching loss. The operation principle and implementation of the controller in the GD are thoroughly described. It can be observed that the new GD controls both dvCE/dt and diC/dt accurately independent of the variable parameters. The new control method is verified by experimental results. As a current issue, the known trade-off between switching losses and EMI is improved by this simple and effective control method.

A simple adaptive feedback control method for chaos and hyper-chaos control

The direct torque control (DTC) system, which is based on induction machine drive is a developed and simple control method. It allows high dynamic performance with very simple hysteresis control scheme; However, its disadvantages are high current, torque, and flux ripple. In this paper, DTC of induction machine drive has been improved by using the applications of artificial intelligence (AI) approaches to reduce the current, torque, and flux ripples and also get better performance of the machines. At the conclusion of this study, the outcomes of traditional DTC and artificial intelligent methods are compared. By the program MATLAB/SIMULINK, the modeling and simulation results of the DTC system for induction machine (IM) have been proposed.