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Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN: 2278-0181Vol. 6 Issue 09, September - 2017Design and Simulation of a DC - DC BoostConverter with PID Controller for EnhancedPerformanceMirza Fuad Adnan, Mohammad Abdul Moin Oninda, Mirza Muntasir Nishat, Nafiul IslamDepartment of Electrical and Electronic Engineering, Islamic University of Technology (IUT)Board Bazar, Gazipur-1704, BangladeshAbstract— This paper proposes the design and simulation of aDC-DC Boost converter employing PID controller, enhancingoverall performance of the system. The main objective of a DCDC converter is to maintain a constant output voltage despitevariations in input/source voltage, components and load current.Designers aim to achieve better conversion efficiency, minimizedharmonic distortion and improved power factor while keepingsize and cost of converter within acceptable range. A simple PID(Proportional, Integral and Derivative) controller has beenapplied to a conventional Boost converter and tested inMATLAB-Simulink environment achieving improved voltageregulation. The proposed closed loop implementation of theconverter maintains constant output voltage despite changes ininput voltage and significantly reduces overshoot therebyimproving the efficiency of the converter. The output of thisinvestigation has the potential to contribute in a significant wayin electric vehicles, industry, communication and renewableenergy sectors.Keywords— DC-DC converter; voltage regulation; Boostconverter; overshoot; PID; Block Diagram Reduction; stabilityI.INTRODUCTIONPower Electronics is ushering in a new kind of industrialrevolution due to its versatility in terms of fields of applicationlike energy conservation, renewable energy system, bulk utilityenergy storage, electric and hybrid vehicles and industrialautomation. When it comes to power conversion, a DC-DCconverter plays a significant role resulting in widespreadapplications in cellular phones, laptop computers, LED drivers,maximizing energy harvest for photovoltaic systems and forwind turbines, electric vehicles, hydro power plants and manymore [1]-[4]. This widespread application requires that theconverter should achieve highest efficiency, minimized totalharmonic distortion (THD) and improved power factor (PF) atthe load side while at the same time reducing size and cost ofthe device and increasing availability [5]-[8].Fig. 1. Block Diagram of a DC-DC ConverterIJERTV6IS090029An electric power converter, DC-DC converter or morecommonly known as a switched mode DC-DC converter asshown in Fig.1, either steps up or steps down the sourcevoltage, Vs according to the requirement of the load connected,by making adjustments in the duty cycle applied to theswitching device (in most cases MOSFETs and IGBT’s).In a DC-DC converter it is always desirable that a constantoutput voltage, Vo is achieved despite changes in the sourcevoltage, Vs, the load current, iLoad and variations in elementvalues of the converter circuit [10], [11]. These disturbancescan be originated from second harmonic periodic variations ofan off - line power system generated from the rectifier circuitand applied to the DC-DC converter, variation of the sourcevoltage Vs due to switching (on/off) of neighboring powersystem loads and variations in the load current, iLoad amongstmany. There are various types of DC-DC converters namely –Buck, Boost, Buck-Boost, Cuk, Sepic and Zeta. One of themost prominent research interests in this era is the applicationof DC-DC converters with high step-up voltage gain.Several control techniques have been proposed to ensurestability as well as fast transient response namely - Fuzz Logiccontroller, Artificial Neural Network (ANN), PID controllerand PI controller. Several Optimization techniques such asGenetic Algorithm, Particle Swarm Optimization, and BacterialForaging Optimization have also been proposed [11], [12],[20], [21].Amongst all converters, most widely used DC-DCconverter is the Boost converter, a step up converter whichprovides a higher voltage at the load side, Vo compared to thesource voltage Vs. Open loop mode of operation of Boostconverter exhibits substandard voltage regulation andundesirable dynamic response. Therefore, closed loop mode ofoperation is preferred for proper voltage regulation andperformance enhancement.In this paper proper voltage regulation of Boost converter isachieved employing PID controller, tuned using trial and errormethod to find appropriate values for the proportional, integraland derivative gains, thereby improving converter performance.Section II of this paper deals with the conventional Boostconverter followed by a brief idea about PID Controller inSection III, Section IV depicts the proposed converter andfinally the simulation and results are presented by comparingthe conventional Boost converter with the proposed ormodified Boost converter with PID controller in section V. Theproposed circuit parameters, simulation and experimentalresults demonstrate the effectiveness and feasibility of theproposed scheme.www.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)27

Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN: 2278-0181Vol. 6 Issue 09, September - 2017II. CONVENTIONAL BOOST CONVERTERA conventional DC-DC Boost converter is composed of aboost inductor, two semiconductors (a diode and a transistor)and an output capacitor in parallel with the load as shown inFig. 2.Transistor switching period is given byMode 1Ton DTpMode 2Toff 1 D Tp(1)Voltage across the inductor,LMode 1di VidtdiL (Vi Vo )dtMode 2(2)Putting equation (1) in equation (2)LMode 1LMode 2Fig. 2. Conventional Boost ConverterBoost converter also known as an up converter provides anoutput voltage that is greater than the input voltage. Input for aboost converter can be a simple DC source such as a battery,solar panel or can be obtained directly from an AC sourcethrough a rectifier. The inductors tendency to resist currentvariations due to changes in the magnetic field is the keyprinciple that drives the Boost converter. Boost converter issaid to operate in two modes. The switching is achieved usingeither a MOSFET or an IGBT. In low voltage applicationsMOSFET is preferred over IGBT due to its highercomputational speed compared to IGBT. Modes of operation ofBoost converter is as follows: Mode 1 begins at t 0s when the transistor is switchedon causing the rising input current to flow through theinductor L, storing energy in its magnetic field. Duringthis mode of operation as shown in Fig. 3(a) the loadside is completely isolated from the source side.Mode 2 begins at t t1 when the transistor is switchedoff. Inductor, L produces a back emf having oppositepolarity of the Mode 1 due to rapid drop in current. Thevoltage across the inductor and the source minus thesmall forward voltage drop across the diode, D chargesthe capacitor, C and also supplies the load. Theconduction path is shown in Fig. 3(b).Ripple current i ViDTp i Vo Vi(1 D)Tp i , is given by ion Mode 1 ioff Mode 2Vi DTpL(1 D)(Vo Vi )Tp(3)(4)LEquating the ripple current equation (3) and (4) of Mode 1 and Mode 2 ion ioffVi D Vo Vi DVo DViVi Vo DVoVi Vo (1 D)Vo1 Vi 1 D(5)Where,ViVotonInput Voltage, VtoffMOSFET off, secTpSwitching Period, secD iDuty CycleRipple currentOutput Voltage, VMOSFET on, secIII.PID CONTROLLEROne of the simplest and most widely used controller fordecades is the PID controller. PID stands for proportional (P),integral (I) and derivative (D) controller. Fig. 4 shows the blockdiagram of a typical PID controller.Fig. 4. Typical PID control StructureFig. 3. Mode of operation of Boost ConverterIJERTV6IS090029www.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)28

Published by :http://www.ijert.orgInternational Journal of Engineering Research & Technology (IJERT)ISSN: 2278-0181Vol. 6 Issue 09, September - 2017The system under study is the plant to which necessaryexcitation is provided thereby achieving overall closed loopcontrol effectively. A PID can be expressed as –KD s2 KP s KIsKIC s KP KDssoperating machines in industries and researchers aim fordesigning a converter with good voltage regulation andovershoot reduction.C s (6)Where,KPProportional gainKIKDIntegral gain(a)Derivative GainThe signal e(t) as shown in Fig. 4 represents the trackingerror obtained from the difference between the reference signalwhich serves as the input R(t) and the actual output signalVo(t). The tracking error is fed on to the PID controller whichcomputes the derivative and integral of the signal provided.The output of the PID controller u(t) to be applied to the plantis equal to the proportional gain (KP) times the magnitude ofthe error signal plus the integral gain (KI) times the integral ofthe error signal plus the derivative gain (KD) times thederivative of the error signal.(b)Time domain representation of the signal u(t) fed to theplant is given by –u (t ) K P e t K I e(t )dt K Dde(t )dt(7)The plant on receiving the signal u(t) will generate amodified output Vo(t) which will be again compared to thereference signal until the desired level is reached therebyforming a close loop system. Effect of proportional, integraland derivative control on close loop system is summarized inthe Table I. provided below.TABLE I.EFFECT OF PID ON CLOSE LOOP SYSTEMSteadySettlingState ErrorRise Change(d)Fig. 5. Block diagram reduction of proposed PID controllerThe controllers can be implemented individually as well asin combination, with the converters to obtain the desired result.IV. PROPOSED CONVERTERThe proposed converter as shown in Fig. 6 is similar to theconventional Boost converter as shown in Fig. 2 but differsonly in the incorporation of a PID controller which isextensively used in many practical applications for betterperformance. The proposed PID controller has been obtainedby block diagram reduction method in four stages as shown inFig. 5. The first figure, Fig. 5(a) depicts a conventional PIDcontroller block diagram when in successive stages as shown inFig. 5(b), Fig. 5(c) and Fig. 5(d), by block diagram reductiontechnique the proposed control scheme for the Boost converterwas obtained as shown in Fig. 5(d) which is feasible forproposed converter. Initial overshoot is a prime concern forIJERTV6IS090029Fig. 6. Proposed Boost converter with PID controller for voltage regulation andovershoot reductionwww.ijert.org(This work is licensed under a Creative Commons Attribution 4.0 International License.)29