Study on the position control of the e-actuator for e-VGT
The e-VGT (electrical Variable Geometry Turbocharger), a kind of turbocharger is a electronic device that controls the flow rate and amount of exhaust gas. Therefore, the position of the actuator must be controlled quickly and accurately. To control the position of the e-actuator, the authors use PI control on a position controller including a current controller. However, since the e-actuator has big friction and spring force, a general PI controller isn't suitable for the e-actuator. To solve the problem, they find mechanical modeling of the e-actuator. And using the mechanical modeling, the controller that is suitable for the e-actuator is made.
Microprocessor-Based High-Efficiency Drive of a DC Motor
This paper presents a method to improve the efficiency of dc motors, dc shunt motors, and dc series motors. The method is based upon the field control. It is derived that the ratio of the armature current to the field current should be maintained constant to maximize the efficiency at a specific speed. The power circuits and the control loops are suggested to realize the principle, and the real-time control is implemented with a microprocessor. Also, in order to assess the stability of the overall systems, the proposed systems are analyzed with the small signal linearization. Experimental results show that the remarkable improvement in efficiency has been accomplished by the proposed method and the suggested systems are stable.
Simulation and control of hybrid renewable energy system connected to the grid
This paper presents a control and simulation of hybrid renewable energy system connected to the grid. The studied system includes a photovoltaic panel, synchronous permanent magnet generator based wind turbine, and a battery for storage energy. The PV array and wind systems are connected to the common DC bus by a boost converter. The battery is connected by a bi-directional DC/DC converter, and then integrated into the AC utility grid via a common DC/AC inverter. In order to extract the maximum energy, a simulation study has been carried out according to the meteorological conditions (wind speed and variable solar irradiance) while maintaining power quality at a satisfactory level. In order to capture the maximum power, a MPPT algorithm is applied for both wind turbine and photovoltaic panel. The modeling and simulation of the whole system has been performed under Matlab/Simulink environment. The obtained results show that the current and the voltage of grid side are sinusoidal and alternative forms, and the power injected to the grid is around the power produced by the hybrid system.