Showing 4 results for Monfared
K. Malekian, J. Milimonfared, B. Majidi,
Volume 5, Issue 1 (March 2009)
Abstract
The main theme of this paper is to present novel controller, which is a genetic
based fuzzy Logic controller, for interior permanent magnet synchronous motor drives with
direct torque control. A radial basis function network has been used for online tuning of the
genetic based fuzzy logic controller. Initially different operating conditions are obtained
based on motor dynamics incorporating uncertainties. At each operating condition, a
genetic algorithm is used to optimize fuzzy logic parameters in closed-loop direct torque
control scheme. In other words, the genetic algorithm finds optimum input and output
scaling factors and optimum number of membership functions. This optimization procedure
is utilized to obtain the minimum speed deviation, minimum settling time, zero steady-state
error. The control scheme has been verified by simulation tests with a prototype interior
permanent magnet synchronous motor.
H. Faraji Baghtash, S. J. Azhari, Kh. Monfaredi,
Volume 7, Issue 4 (December 2011)
Abstract
In this paper a novel very high performance current mirror is presented. It favorably benefits from such excellent parameters as: Ultra high output resistance (36.9GΩ), extremely low input resistance (0.0058Ω), low output (~0.18V) and low input voltage (~0.18V) operation, very low power consumption (20μW), very low offset current (1pA), ultra wide current dynamic range (150dB), and ultra high accuracy (error = 0.003%). The circuit has a very simple compact architecture and uses a single 1V power supply. The qualitative performance of the circuit is validated with HSPICE simulations using HSPICE TSMC 0.18μm CMOS technology.
M. Oloumi, R. Ghazi, M. Monfared,
Volume 11, Issue 2 (June 2015)
Abstract
This paper provides a detailed comparative study concerning the performance of min-projection strategy (MPS) and model predictive control (MPC) systems to control the three-phase grid connected converters. To do so, first, the converter is modeled as a switched linear system. Then, the feasibility of the MPS technique is investigated and its stability criterion is derived as a lower limit on the DC link voltage. Next, the fundamental equations of the MPS to control a VSC are obtained in the stationary reference frame. The mathematical analysis reveals that the MPS is independent of the load, grid, filter and converter parameters. This feature is a great advantage of MPS over the MPC approach. However, the latter is a well-known model-based control technique, has already developed for controlling the VSC in the stationary reference frame. To control the grid connected VSC, both MPS and MPC approaches are simulated in the PSCAD/EMTDC environment. Simulation results illustrate that the MPS is functioning well and is less sensitive to grid and filter inductances as well as the DC link voltage level. However, the MPC approach renders slightly a better performance in the steady state conditions.
H. Faraji Baghtash, Kh. Monfaredi,
Volume 15, Issue 3 (September 2019)
Abstract
A novel active feedback frequency compensation scheme is presented in this work. Based on the proposed technique, an amplifier with two main poles in its frequency bandwidth can be easily compensated by introducing a pole-zero pair in a local feedback. The proposed method is mathematically analyzed and then based on the derived formulations, a design procedure is established. The capability of the proposed technique is examined considering a well-known two-stage amplifier, considering just a trivial modification on its input stage. To gain an analogous and fair insight, the performance of the proposed structure is compared with that is of the optimally designed miller-compensated two-stage amplifier. The post-layout simulations are accomplished with TSMC 180nm CMOS standard technology. The Spectre post-layout simulations show that the proposed structure outperforms the traditional structure in terms of power consumption and gain bandwidth product. The robustness of the design is checked with Monte Carlo simulations.
