A sliding mode fuzzy control method which combines sliding mode and fuzzy logic control for DC-DC boost converter is designed to achieve robustness and better performance. A fuzzy sliding mode controller in which sliding surface whose reference is obtained from the output of the outer voltage loop is used to control the inductor current. A linear PI controller is used for the outer voltage loop. The control system is simulated using Matlab/Simulink. The simulation results are presented for input voltage and load variations. Simulated results are given to show the effectiveness of the control system.

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Fuzzy Sliding Mode Control of DC-DC Boost Converter

This paper investigates the operation and analysis of the photovoltaic water pumping system in detail. Power electronic controllers were designed and developed for the water pumping system using a boost converter along with an inverter followed by an induction motor pump set. The proposed system could be employed in agricultural irrigation under any operating condition of varying natures of solar irradiances and temperatures. The configuration and implementation of the system were described in detail. Further, the detailed method of analysis and simulation characteristics of such PV water pumping system was also presented.With the concern of shortage of fossil fuel, global warming and energy security, the proposed PV based water pumping system can meet the significant demand of electricity and serve for the agricultural sector.

PV based water pumping system for agricultural irrigation

This study dealt with output voltage regulation of boost converter using observer based sliding mode controller comprises of adaptive PI sliding surface. Observer was designed to estimate the inductor current value, such that no sensor was required as a feedback. Adaptive PI sliding surface was constructed from the difference between estimated inductor current and its reference value. The stability of proposed method was ensured by using Lyapunov direct method. To test the system performance, numerical simulation was conducted. The result indicated that the integral absolute error value of proposed method was 0.19, which was 7 times less than sliding mode with PI sliding surface. Consequently, the proposed method was able to estimate accurately the inductor value, track the reference voltage perfectly, and show its robustness against parameter variations.

Voltage Regulation of Boost Converter using Observer based Sliding Mode Controller

Ice-clamping devices are of great advantage in deformation-free and sustainable workpiece clamping by using frozen water to fix pieces during machining operations. The adhesive bonding of ice generates high forces, encapsulating the piece form-fitted around and underneath its surface. The freezing is generated by thermoelectric coolers (TECs), placed under a clamping plate. The colder the plate is chilled, the higher the total forces of ice bonding are, guaranteeing a secure grip during machining. However, process heat generated by machining tools pose the risk of thawing the ice, illustrating an external disturbance which is needed to be controlled. Traditional control strategies for TECs use PID algorithm due to its simplicity. To attenuate disadvantages of a PID controller, such as oscillations, overshoots and settling time as well as to attain a better performance and robustness in the presence of parameter uncertainties and disturbances, a model based feedforward regulator including Anti-windup method is proposed additionally to a PI controller for the nonlinear thermal system. Furthermore, a technical requirement is formulated mathematically proving the existence of a structural stability of the thermal system. Simulation results, performed in MATLAB Simulink, are shown and are validated with experimental data.

A model based feedforward regulator improving PI control of an ice-clamping device activated by thermoelectric cooler

Renewable energy sources, such as photovoltaic, fuel cell and wind energy are becoming a sustainable alternative to non-renewable sources like fossil fuel. However, to integrate these energies into the grid, power electronic converters plays major role due to their power conditioning capability, reliability and effectiveness. In this paper, design, modeling and analysis of a DC-DC boost converter with robust controlling technique, fuzzy sliding mode controlling strategy has been developed and a brief comparison has been performed with a sliding mode controller and a clasical PID controller which employed both current and a voltage control loop. The system is designed to achieve a fast dynamic response, zero steady-state error, and satisfactory stability. To realize that a detailed mathematical derivation of sliding mode fuzzy logic controller and a linearized small signal model of the power electronic converter around its DC steady state operating point is performed. Finally, in order to evaluate the designed system, a software simulation based on MATLAB/ Simulink environment is developed and results of the simulation shows the effectiveness of the proposed techniques.

Robust DC-DC Boost Converter Control for Integration of Fuel Cell with Renewable Energy Sources

This paper presents the design and simulation of a DC-DC boost converter which uses wind energy as input source. Nowadays, wind is a type of renewable energy that is sustainable and clean compared to other alternative energy. Generally wind in Malaysia blows at variably low speed thus producing variably low input voltage as energy source. DC-DC boost converter can be used to increase the output voltage to a level suitable for domestic use. In this project, a closed-loop DC-DC boost converter circuit was designed and simulated using MATLAB SIMULINK based from a topological circuit. In the simulation, the circuit was tested with different low input voltage values to a setpoint of 240V. In order to improve the output voltage transient response, Fuzzy Logic Controller is designed and implemented at the circuit to set the duty cycle of the switching device for the boost converter. The result has indicated better performance for boost DC-DC converter with FLC controller.

Design and simulation of Fuzzy Logic Controller for boost converter in renewable energy application

The Thermoelectric cooler (TEC) is widely known device which have low coefficient of performance (COP) as compare to the conventional compressed refrigerator. However, it is suitable for portable refrigeration that requires light weight, small and fast control. Therefore, the proportional integral derivatives (PID) control was implemented to control input and output while reducing its power consumption. Mathematical model for TEC was develop base on black box model to get its transfer function. The transfer function consist of ratio output and input that been used for analysis during development of controller. This study is focus on performance of PID controller in simulation and real hardware in order to reduce time constrain. The method proposed is integral of time multiplied absolute value of error (ITAE) criteria to determine the coefficient of PID controller. The finding shows that the lowest temperature is 7 °C and the time taken is around 940 second.

Design and development of controller for Thermoelectric cooler system

This study investigates the characteristics of knee cartilage hydrogel of Poly(vinyl)alcohol (PVA) based scaffolds which fabricated with different proportion of gelatin and Polycaprolactone (PCL) using swelling test, scanning electron microscopy (SEM) and tensile test. Two different hydrogels were fabricated which are Polyvinylalcohol PVA/gel and PVA/PCL. For each type of hydrogel, four samples with different proportion were produced. For the PVA/gel hydrogel, amount of gelatin was increased in each sample (2.5g, 3.0g, 3.5g, and 4.0g). It was also done to PVA/PCL sample where amount of PCL was increased in each sample. Amount of PVA was kept constant. Swelling test was done by drying the samples and immersing them in distilled water for 24hours. SEM was used to observe the morphological characteristics of the samples. Lastly, the strength of the samples were collected directly from the graph and raw data obtained by using Universal Testing Instron machine. Swelling test has shown the increasing data for both PVA/gel and PVA/PCL of increasing amount while the combination of PVA/gel has shown greatest tensile strength compared to PVA/PCL whereas SEM examination has shown the contribution of porogen for porosity of hydrogel scaffolds.

Development and characterization of PVA based hydrogel for cartilage tissue scaffold

A 3-dimensional hip joint implant model was constructed which separates into three individual parts namely femoral stem with neck, femoral head and acetabular cup. Each part were assigned with the specific materials and a total of 3000 N loads was applied to mimic the body weight of an adult in static position or in double leg standing position. The results of the stress distribution were obtained from the finite element analysis for the difference diameter for each component of ball-socket and neck as well as the difference materials. The results showed that an optimum diameter of femoral ball-socket with 36 mm and titanium alloy have design rigidity which provided better performance and longer life span based on 13.922 Mpa equivalent stress .

M. Normahira

Papers

Design and simulation of Fuzzy Logic Controller for boost converter in renewable energy application

Design and development of controller for Thermoelectric cooler system

Development and characterization of PVA based hydrogel for cartilage tissue scaffold

An Investigation on Rigidity of Ball-Socket Hip Joint Replacement