Sliding Mode Control of Buck Converter

DC-DC converters are used to convert DC voltage from one level to other. These converters are drastically used in industry as well as in research. One of the main limitations of these converters is unregulated supply of voltage and current. To overcome these problems there are various control techniques. This paper presents two such methods. This paper compares dynamic performance of buck Converter using PID controller and Sliding mode controller. Simulation of PI and Sliding mode control of Buck Converter is carried out in MATLAB SIMULINK

Indirect Vector Control of Three Phase Induction Motor using PSIM

This paper presents the implementation of indirect vector control of three phase Induction Motor using Hysteresis Band PWM current control and Synchronous Current Control in PSIM environment. In any machine drive system, current control directly influences both flux and torque developed directly. In Hysteresis current control method, actual current tracks the command current within a hysteresis band. There is no difficulty in current control tracking when CEMF is low, but at higher speeds, current controller gets saturated due to higher CEMF and hense becomes difficult to track due to which there will be a phase lag with respect to command current. All such problems are solved using Synchronous Current Control.

Full Order Observer Based Control of Single-Phase Inverter Both in Standalone and Gridtie Modes

In 3-phase systems, the reliability of 3-phase Inverter is not good. In such situations Paralleled Inverter Systems are used. Parallel Inverter operation has a major topic in uninterruptible power system (UPS) applications where the design is focused on the standalone operation, and output stage is typically an inductor-capacitor filter. Most of the standalone inverter systems use a LC filter and proportional-integral (PI) controller in their control loops. When connecting the paralleled inverters to utility grids, the capacitor becomes redundant and thus either a pure inductor or an LCL filter can be used as inverter output stage. Compared with the L filter, the LCL filter is more attractive because it cannot only provide higher harmonics attenuation with same inductance value, but also allow inverter to operate both in standalone and grid-tie modes, which makes it a universal inverter for distributed generation applications. Output of Inverter should always be checked. In this paper, a full order observer for Inverter System is designed and is used for estimation of State Variables of the Inverter System. Two modes are adopted: a) Grid-tie Mode b) Standalone Mode. MATLAB/Simulink is used to verify and validate the proposed idea

Sliding Mode Control of Buck Converter

DC-DC converters are used to convert DC voltage from one level to other. These converters are drastically used in industry as well as in research. One of the main limitations of these converters is unregulated supply of voltage and current. To overcome these problems there are various control techniques. This paper presents two such methods. This paper compares dynamic performance of buck Converter using PID controller and Sliding mode controller. Simulation of PI and Sliding mode control of Buck Converter is carried out in MATLAB SIMULINK

Comparative Analysis of Implementation of SVPWM for Three phase Voltage Source Inverter in Linear and Over modulated regions

In this paper Space Vector Pulse Width Modulation for three phase voltage source is implemented both in Linear and Over-modulated regions. The maximum sinusoidal output is reached if the reference is equal to 1/√3Vdc, and the trajectory is a circle inscribed inside the hexagon which is called Linear Modulation range. If reference is more than this value, then it is called Over modulation range. In both the regions, SVPWM is implemented using MATLAB and results are compared

Improved Dynamic Response of Buck Converter using Fuzzy Controller

This paper presents comparative performance of Buck Converter in both open as well as closed loop. With the help state equations Mathematical Model of Buck Converter is designed in MATLAB/SIMULINK. The obtained output response of open loop Buck Converter is sluggish, not optimum and consists of peak overshoots. PI Controller is used in closed loop model of Buck Converter. Output Voltage is compared with a reference signal, which then is processed through a controller (PI/Fuzzy). The obtained signal is superimposed with a carrier signal and given to switching device used. To further optimize the performance of Buck Converter and eliminate the peak overshoot present in output response, Fuzzy controller is used. Here Suguno type Fuzzy is used

Improved Step Response of Power System Stabilizer using Fuzzy Logic Controller

As every power system is constantly being subjected to disturbances, we should see that these disturbances do not make the system unstable. Therefor additional signals derived from speed deviation, excitation deviation and accelerating power are injected into voltage regulators. The device to provide these signals is referred as power system stabilizer. The use of power system stabilizers has become very common in operation of large electric power systems. The conventional PSS which uses lead-lag compensation, where gain settings designed for specific operating conditions, is giving poor performance under different loading conditions. Therefore, it is very difficult to design a stabilizer that could present good performance in all operating points of electric power systems. In an attempt to cover a wide range of operating conditions, Fuzzy logic control has been suggested as a possible solution to overcome this problem. In this paper, a systematic approach to fuzzy logic control design is proposed. The study of fuzzy logic power system stabilizer for stability enhancement of a single machine infinite bus system is presented. In order to accomplish the stability enhancement, speed deviation and acceleration of the rotor synchronous generator are taken as the inputs to the fuzzy logic controller. These variables take significant effects on damping the generator shaft mechanical oscillations. The stabilizing signals were computed using the fuzzy membership function depending on these variables. The performance of the system with fuzzy logic based power system stabilizer is compared with the system having conventional power system stabilizer and system without power system stabilize