Abstract of DC/DC CONVERTER BY USING FPGA

In this paper there is discussion about the FPGA technology how this technology can be implemented to remove the voltage spikes that are not required and this technology also used to remove the static voltage errors from the DC/DC boost converter. This technology is used to remove the voltage spikes when impedance load is changed instantly. The FPGA stands for field programmable gate array. This system is used to control the dynamic behavior of such system in practical. Through the use of this FPGA technology it is very easy to implement such control algorithms that can able to work in real time and also their sampling period is very low. The required output can be achieved through parallel implementation of control algorithms. In this paper there are some experimental results through the use of FPGA technology in boost converter.

Keywords: FPGA, boost converter, dynamic behavior of voltages, DC/DC converter, switching converter. 

INTRODUCTION of DC/DC CONVERTER BY USING FPGA

The use of DC/DC converter in the field of electrical has very vast application like the power supplies used for the electronic circuits. The DC/DC converter is also used in DC electric motors and also for converting the high level and low level DC voltages. The load impedance can be change through the use of different capacitance and inductive loads. The condition in which the voltage overshooting occurs at the output of the DC-DC converters so this condition is not reliable for these converters any may cause damage to the other electrical appliances like electric motor. Later on whenever the sudden change in the output voltage occur, this change occur when load impedance changes. This is quite real when ever any voltage disturbance occurs in any electrical appliances due to voltage overshoot so this FPGA technology covers that phase of voltage overshoot in any electrical system.

For the practical measurement there are some experiments that have been performed by making a model of DC-DC boost converter and use FPGA technology. The model can be implemented through different impedances in the circuit. In MATLAB different simulations has been proposed regarding this boost converter. In this report there are some experiments that has been proposed through using this concept.

LITERATURE REVIEW of DC/DC CONVERTER BY USING FPGA

According to the author Spino he has proposed a work about the DC/DC boost converter this has be done through the use of FPGA technology. A correct model for the DC/DC boost converter has been presented through FPGA technology implementation. The two hardware designs of the converter has been presented through different FPGA footprints. This explicit design of the buck boost DC/DC converter has been designed and this design will help to allow efficient circuit implementation. In this paper there are two controllers that have been implemented on FPGA  [1]

For the DC-DC converter how feed forward controller can be implemented. For the conventional DC/DC converter topologies like buck, boost, Cuk and buck-boast converters have their own controlling techniques for certain applications. The voltage regulator is used to maintain the constant voltages at the output of these converters whenever a current or voltage change occur at the input of these converters. For this a range of controlling technique has been implemented for linear and nonlinear control of these converters. These controlling techniques are used to overcome the dynamic changes in the output of the system. These controllers can be classified as the proportional, proportional-integral-dynamic and also proportional-integral. These all controllers are used to control the active behavior of these converters. This linear control of the converter is not sufficient to face high changes in then line voltages and also in load current. But the nonlinear control techniques like the Fuzzy logic control, genetic algorithm, Adaptive Neutral Network and also many other controlling techniques are used to increase the performance of these converters. There are many controlling techniques that have been implemented through the use of FPGA technology.

For controlling the output voltage of these converters PID auto-tuning technique is used. This technique is used to control the DC/DC boost converters through the use of relay feedback techniques. The controller parameters are used to maintain the output level of these converters. These parameters of the controllers are used to control the output of these converters. This controller parameter is tuned and used as the PID regulator. This technique is used to remove the effect of parasitic resistance and inductance in the output capacitor of these converters.  That produces a lot of noise at the output of DC/DC converter so by using this technique of feedback control through PID controller this noise can be reduce easily.

The author Elshaer has proposed control technique for the DC-DC boost converter that is PID controller in a Photo voltaic system. This controller can be tuned through the help of Genetic algorithm for the regulation at the output voltage. For tuning the proportional, integral and derivative gain of this PID controller the Fuzzy-PID controller was used. For controlling the duty cycle of the boost converter a smart controller was used for this research. For the fixed frequency at the input a nonlinear controller was proposed. For the power amplifier a four switch non inverting Buck boost converter is used that is based on the sliding mode control strategy. The ideal advantage of using this controller is that this controller will help to increase the performance, efficiency and energy of the system using these converters [2].

 According to the author Fumio he has designed a nonlinear controller called the fuzzy controller and this controller is used regulate a Cuk converter and also the boost converter. A complete study has been carried out for the output of these converters [3].

According to the author Gupta he has proposed a fuzzy logic controller for controlling the output of the bulk and boost converters for this a common algorithm of these converter. For the experimental implementation of this controller a 8-bit microcontroller is used. This Fuzzy logic controller is used for the steady state output of the boost converter [4].

According to the author Mattavelli he has proposed a main aim of the Fuzzy controller for the bulk-boost converter. In this research the simulation results has been proposed and also proposed a control methodology. According to the author Raviraj, he has developed a linear PI controller, fuzzy controller and also the sliding mode controller [5].

In this paper according to the author Tseng he has proposed a high performance design for the DC/DC switching power converter like the Boost converter. This converter is involved in providing regulated voltage of 50 and current up to 15 amperes. For getting high range of adjustable voltage at the output of the converter a PI gain control scheme has been designed through the use of FPGA chip. In this paper experimental results also has been proposed. Through the use of FPGA technology the issue of limited adjustable output voltage range for these PWM switching converters has been resolved. Also this technique increases the efficiency at the output of the system. Through the use of ZVS technique the output efficiency of the system [6].

According to the author Hyo-Sik he has proposed a fuzzy controller for the boost and buck converter. And this can be done through the use of digital signal possessor that processor is switched at 10 KHz frequency. Then after that an integrated Fuzzy controller is designed and used for the boost converter control and this can be done through current mode control technique [7].

DC/DC BOOST CONVERTER 

PARAMETERS of the DC/DC BOOST CONVERTER

For the parameter first of all there is demonstration about the specifications of the DC/DC boost converter. The input voltage of the converter is set to 400 volts. The inductor, capacitor and load resistor value are calculated through their formulas and the values of inductor is . For the setting of IGBT FET resistance is 0.1 and put the snubber capacitance at infinity. For the setting of diode of the boost converter the resistance is set at 0.001, the snubber resistance is set at 500 and snubber capacitance at . The capacitor for the boost converter is set at 1 the value of the load resistor is set at 20 ohm and the value of the boost converter is not according to the requirement that has been set in the problem. On the basis of these specifications the parameters for the DC/DC boost converter has been calculated

The switching frequency of this power rated boost converter is set to 5 kHz. For finding the inductance value, in the first step find the resistances value according to the diagram and then calculate the value of duty cycle ratio. After this find the rated input current of the inductor. Then through the input current ripple the value of the inductor used for this boost converter can be found easily. The capacitor value of this boost converter can be calculated through the output voltage ripple ratio. The peak switch voltage is equal to the input voltage for this boost converter. The current value of this power diode is 150 A. The phase change in the circuit is measured by IBC circuit design by using Matlab/Simulink software. The block diagram for the PWM signal is generated by Quartus II.

DESIGN of FEED FORWARD CONTROLLER

The DC/DC boost converter is very important in the field of electrical like the electric motors are controlled through these converters. The feed forward controller has been designed for the DC/DC boost converter. This feedback controller has been designed through measuring open loop line regulations that is for the fixed load and can be set up to 5% and the DC input voltage can be changed by 400%. After using this converter the load regulation was also good without the use of negative feedback loop.

The feed forward control of this converter is consists of a comparator. The voltage divider for this controller is composed of the two resistors that are R1 and R2 and the comparator for this controller is an operational amplifier and that is supplied by only single voltage source V. The  is the saw tooth and this voltage is applied at the non-inverting input of the comparator. The peak value of the Saw tooth of voltage is denoted byand this value is set up to 5-10 voltages. The switching frequency of this converter is set according to the frequency of the saw tooth voltage. For the input of this comparator the reference voltage is applied as the inverting input of the comparator. And this reference voltage is denoted by. This reference voltage can be written as

This the prototype of the system that will be implement through the use of MATLAB Simulink. The IBC system development is based on the desired objectives and produced output voltage that is approximately equal to desired voltage. The conventional boost converter indicates higher efficiency, high reliability, lower ripple current, and lower voltage ripples.

After arranging these values this can be written as

The output voltage of this feed forward controller can be found as

Through the substitution of the values the output voltage can be written as

The operational amplifier can be used as the comparator when its slew rate is high enough and the slew rate can be find through assuming the value of rise time and fall time of the gate to source ratio. The slew rate of the operational amplifier can be calculated through

In this equation the  is the peak to peak voltages from the gate to source voltage [8].

For designing the control system for this boost converter set the voltage reference at 1 and for designing the PID controller set the proportional part of the PID controller at 0.7, the integral part of the PID controller is set at 100 and for the advance setting of this controller. The upper saturation limit set at 1 and lower saturation limit at 0.1. Attached the DC-DC PWM generator and set the switching frequency at 5000 and the sampling time up to 1.

MATLAB Simulation of DC/DC CONVERTER BY USING FPGA

The design of the boost converter is implemented on MATLAB Simulink [9].

The voltage waveform of the boost converter can be seen through the help of scope [10]. The voltage is regulated by changing the duty cycle. Figure shows the produced signal by using the waveform Editor (*.vwf). In the present situation, the time for on off switching is considered to compare with the calculated values.

The inside of the feedback controller is like that by setting the gain value of 1/20 the design of the controller is like

After attaching the feed forward controller the boost converter will be looked like this.

The voltage waveform after attaching the feed forward controller the output voltage is also almost according to the requirement. The figure depicts output voltage that is slightly different from the calculated values. the control of duty cycle on the both sides of whole phase is related to the change in voltage. The controllable output voltage is demonstrated in below list.

CONCLUSION of DC/DC CONVERTER BY USING FPGA

Summing up all the discussion from the above it is concluded that the boost converters are very valuable for the electrical applications. For removing the ripples at the output of the boost converter a control technique can be implement that is used to remove the voltage spikes from the output of the boost converter. In this report a system is implemented for removing the line variation and the variation at the output of the boost converter can be done. For removing these errors at the output a technique of feed forward controller is used as the feedback of this boost converter. For setting the value of the parameters of boost converter a feedback controller can be designed. In this report the parameters for the feed forward are designed through setting the values of input voltages. For this report it can be seen that the line voltages are quite better when high load impedance is implemented. At the output of the load regulation the load regulation is perfect at the output of the boost converter.

References of DC/DC CONVERTER BY USING FPGA