Showing 9 results for Hysteresis
Z. Nasiri-Gheidari, H. Lesani, F. Tootoonchian,
Volume 2, Issue 3 (7-2006)
Abstract
Hunting is a flutter associated with the synchronous speed that gives rise to the
gyro drifting errors and may cause objectionable time-displacement errors in video head
wheel drives and other precision scanning systems. In this paper, dynamic characteristics of
permanent Magnet hysteresis motors are presented and hunting is explained. New damping
techniques have been developed using optimized eigenvalues calculation. They are
calculated from LQR optimization method. In this damping method, a distinct reduction in
hunting has been archived. Furthermore field oriented control result of motor is presented
that have good effect on Hunting. Nearest agreement between simulated and measurement
results shows the accuracy of motor model. Comparison between this paper results and
other measured damping methods result are shown its success.
A. Darabi, T. Ghanbari, M. Rafiei, H. Lesani, M. Sanati-Moghadam,
Volume 4, Issue 4 (12-2008)
Abstract
Hysteresis motors are self starting brushless synchronous motors which are
being used widely due to their interesting features. Accurate modeling of the motors is
crucial to successful investigating the dynamic performance of them. The hysteresis loops
of the material used in the rotor and their influences on the parameters of the equivalent
circuit are necessary to be taken into consideration adequately. It is demonstrated that some
of the equivalent circuit parameters vary significantly with input voltage variation and other
operating conditions. In this paper, a comprehensive analysis of a hysteresis motor in the
start up and steady state regimes are carried out based on a developed d-q model of the
motor with time-varying parameters being updated during the simulation time. The
equivalent circuit of the motor is presented taking into account the major impact of the
input voltage. Simulation results performed in Matlab-Simulink environment prove that the
existing simple models with constant parameters can not predict the motor performance
accurately in particular for variable speed applications. Swings of torque, hunting
phenomenon, improvement of power factor by temporarily increasing the stator voltage and
start up behavior of the hysteresis machine are some important issues which can accurately
be analyzed by the proposed modeling approach.
S. M. Mirimani, A. Vahedi, M. R. Ghazanchaei, A. Baktash,
Volume 9, Issue 2 (6-2013)
Abstract
Hysteresis motor is self-starting synchronous motor that uses the hysteresis characteristics of magnetic materials to make torque. There are different methods to model this kind of motor and take into account the magnetic hysteresis characteristic of the rotor hysteresis ring. In this investigation the application of complex permeability concept is implemented to model the hysteresis loop and the hysteresis loop in inclined ellipse shape is adopted. To the best knowledge of the authors, this has not been studied before. Based on this concept, simulation of hysteresis motor in conventional configuration is done in order to obtain the output values of motor using 3D Finite Element Model (FEM). This 3D finite element model has high level accuracy and gives better insight of motor performance. Meanwhile, in order to validate the simulation results an experimental set up is provided and the output values of typical motor are measured. It is shown that there is a good agreement between experimental and simulation results.
i, Abolfazl Vahedi, , r, avahedi@iust.ac.ir(Corresponding author), ,
A. Vahedi, A. Baktash,
Volume 11, Issue 1 (3-2015)
Abstract
Recently, tape wound cores due to their excellent magnetic properties, are widely used in different types of transformers. Performance prediction of these transformers needs an accurate model with ability to determine flux distribution within the core and magnetic loss. Spiral structure of tape wound cores affects the flux distribution and always cause complication of analysis. In this paper, a model based on reluctance networks method is presented for analysis of magnetic flux in wound cores. Using this model, distribution of longitudinal and transverse fluxes within the core can be determined. To consider the nonlinearity of the core, a dynamic hysteresis model is included in the presented model. Having flux density in different points of the core, magnetic losses can be calculated. To evaluate the validity of the model, results are compared with 2-D FEM simulations. In addition, a transformer designed for series-resonant converter and simulation results are compared with experimental measurements. Comparisons show accuracy of the model besides simplicity and fast convergence
H. Heidarzad Moghaddam, M. Salimi,
Volume 11, Issue 3 (9-2015)
Abstract
Hysteresis current control method is vastly used in PWM inverters because of simplicity in performance, fast control response and good ability in limiting peak current. However, switching frequency in hysteresis current control method with fixed bandwidth has large variation during a cycle and therefore causes non-optimal current ripple generation in output current. One of basic problems in implementing hysteresis current control is its variable switching frequency that causes sound noise and increase in inverter losses and also high frequency current components injection to the source current. In this paper, in addition to the calculation of variable hysteresis bandwidth equation that fixes frequency switching, also other problems can be solved by removing the derivative part. Here, a shunt active filter has been used for removing the current harmonic components generated by non-linear loads. Proposed method is simple to perform and reliable, and also has been simulated in MATHLAB software environment
A. Kumar, P. Kumar,
Volume 15, Issue 4 (12-2019)
Abstract
This paper presents the three topologies of three-phase four-wire DSTATCOM for reduction of harmonics, reactive power compensation, increasing power factor, which occur due to a nonlinear load, environment problem and polluted grid. The performances of the above topologies have been compared for the magnitude of source current, power factor improvement, DC-link voltage regulation, and total harmonic distortion. This paper presents a novel work for the new young scientist /industrialist who working in the improvement of power quality in the grid. This paper helps to provide the application, designing constraints of shunt active filter in many fields. The First topology which is used in this paper is the three-phase four-wire four-pole voltage source converter based DSTATCOM. The second is the three-phase four-wire with three-leg voltage source converter based DSTATCOM with T-connected transformer and the third topology is the three H-bridge voltage source converter based DSTATCOM. The T-connected transformer in the second topology has been used to reduce the rating for voltage source converter. Synchronous reference frame theory based controller has been proposed to the generation of the reference current. Reference current generated from the synchronous frame theory is processed to hysteresis current controller loop which produces switching pulses for VSC based DSTATCOM. All these topologies have been implemented in MATLAB /Simulink platform by using different types of loading conditions such as resistive and power electronics load.
Vahid Jamshidi, Mohammad Mehdi Bordbar,
Volume 20, Issue 2 (6-2024)
Abstract
Nonvolatile computing have been shown to be effective in the face of the sudden power outage for wireless sensor networks, Internet-of-Things applications, data converters, and emerging energy-harvesting circuits. It also plays a significant role in power-gating to minimize the leakage power for improving the energy efficiency. However, using on-chip backup module for D flip–flop has a bottleneck, and result in an increase in total power consumption, occupied area, and reduced calculation speed. Furthermore, the backup module needs external control signals, which increases the complexity of the circuit. This paper proposes a novel nonvolatile flip-flop with simultaneous data backup capability, which uses NCFET ferroelectric transistor to fundamentally advance the non-volatile computing paradigm. Proposed NVFF exhibits 0.8% faster and 5.0% smaller energy than previous works, while uniquely providing Radiation-Hardened feature.
Chhaya Belwal, Kunwar Singh, Shireesh Kumar Rai,
Volume 20, Issue 2 (6-2024)
Abstract
This paper introduces a floating flux-controlled meminductor emulator, implemented using two voltage differencing differential difference amplifier (VDDDA) along with a memristor and capacitor. Grounded and floating configurations are simulated with TSMC 0.18 µm level-49 BSIM3 CMOS process parameters in LTspice, showcasing the performance of the proposed circuits. The circuit features electronic tunability, allowing for the adjustment of nonlinear flux through the tuning of bias voltage. Simulation results validate the frequency-dependent current-flux dynamics of the proposed meminductor emulator. The simulation results, which involve frequency-dependent pinched hysteresis loops, transient analysis, non-volatility, and Monte Carlo analysis of the proposed meminductor, affirm the functionality and adequacy of the proposed design. A Chua’s oscillator is realized using proposed VDDDA-based meminductor as non-linear element.
Zahra Emami, Abolfazl Halvaei Niasar,
Volume 21, Issue 3 (8-2025)
Abstract
Multiphase electric motors are useful for industrial and military applications that need high power, fault tolerance control, smooth torque, and the ability to share power and torque compared to conventional three-phase electric motors. One type of Multiphase electric machine is Brushless DC Motors (BLDCM) which uses conventional strategies such as hysteresis current controllers. It has important challenges such as high torque ripple, low efficiency, vibrations, and noise that are undesirable for high power applications such as submarines. This paper proposes a new finite control set model predictive control (FCS-MPC) approach with reduction of computational for diode-clamped three-level (DC3L) inverter fed to dual three-phase BLDCM (DTP-BLDCM) by selecting optimal vectors to solve the above problems. Also, an approach of balancing the voltage of the capacitors in two of the DC3L inverters to reduce torque ripple has been proposed. The results of the suggested MPC method are contrasted and verified with the multiband hysteresis current (MHC) method through simulation. The simulation results specify that the suggested MPC controller works superior than the MHC controller. Also, due to the simplicity and low complexity of the suggested MPC strategy used, the real implementation possibility and performance of the controller are checked by simulations for a 4125-V/2.7-MW/350-RPM DTP-BLDCM.
