KY Converter Fed Dc Motor For Low Power Application

. This paper aims to design and to simulate a various DC-DC Converter with closed loop control. DC-DC converter is electronic co converter converts direct current source from one voltage to the level voltage. It is a type of electric power converter. The range of power vary from very low to very high. MATLAB Simulink has been used in modelling and simulation of the circuits. We have analysed the closed loop control of various DC-DC converters like buck, boost, buck-boost and KY converters using MATLAB Simulink. The KY converter is chose for the low power application and the same was designed and simulated.


1.Introduction
Portable electronic devices using DC-DC converters, such as cell phones and laptops, are primarily powered by batteries.These electronic devices often contain multiple sub-circuits, each with its own voltage level requirements that differ from those supplied by the battery or external power source.Also, the battery voltage decreases as the stored energy is depleted.To increase voltage from a partially lowered battery voltage the switched DC to DC converters offer a method by saving space instead of using multiple batteries to accomplish the same thing.KY converter, a voltage boosting converter is proposed to operate in continuous conduction mode (CCM).It has the advantages of no ripple current, low output ripple and good load transient response.Solar panels are used to provide DC power and batteries store this DC voltage.The KY converter is provided with the voltage stored in the battery for boosting its voltage level.The output of the converter circuit KY is then sent directly to the load.It produces a continuous output with a reduced number of ripples.[1,2] Through Simulation the voltage mode control is tested by tuning a PID controller, and its operation is tested.The industries have been using Proportional-Integral-Derivative (PID) controllers for several decades for process control applications.PID involves three separate parameters, the proportional, the integral and derivatives.By defining three constants in the PID controller algorithm, the controller can provide control actions designed for specific process requirements.In a PID controller implemented in a closed-loop system, the tracking error, the difference between the desired input value and the actual output, is represented by a variable.The PID controller receives this error signal and the controller calculates the derivative and the integral of this error signal.The signal that has just passed through the controller is now equal to the proportional gain multiplied by the magnitude of the error plus the integral gain multiplied by the integral of the error plus the derivative gain multiplied by the derivative of the error which will be sent to the device and the new output will be obtained.The new error signal would be generated when the former output is fed back to the sensor.The duty cycle of the PWM signal applied to the semiconductor switch and MOSFET is controlled by the PID controller as per the output requirement.The input voltage is taken as 36V.With the reference voltage the operation of the converters can be best verified.It has been shown by the results that the designed PID controller has better output voltage tracking ability, thus improving output voltage regulation.The controller exhibits a better output voltage tracking with minimal overshoot, small steady state error, shorter settling time, and higher converter efficiency.[3,4]   The fig. 1 shows the circuit diagram of Buck converter.When the switch is turned ON, diode will be in OFF.The source current flows will be equal to inductor current and the charging of inductor takes place.When the switch is turned OFF the diode starts connecting and the inductor acts as source and it discharge.[5] , 01

Table 1. Comparative Analysis of DC-DC Converters
The table1 show the comparative analysis of various DC-DC converters.On analysing various converters like buck, boost, buck-boost under same design parameters we found that KY converter showed very low ripples and non-pulsating current.Also, among the other converters the efficiency seemed comparatively high and thus we chose KY converter.Closed loop control systems are more accurate even in the presence of non-linearities.The sensitivity of the system may be made small to make the system more stable.On analysing the closed loop control of various converters like buck, boost, buck-boost and KY under same design parameters we found that KY converter the system seemed very stable.The fig. 13 shows the block diagram of the proposed system.A voltage increase converter is proposed which makes use of a rate pump and a coupled inductor in the KY converter.As a greenhouse-boost converter blended with synchronous rectification that is in the form of replacing diodes with MOSFET switches, Its far voltage-set up converter is operated.A PV cell that is a solar cell fed to the proposed converter.DC output is produced.To enhance the DC voltage the increased form of converter combines the KY converter.Right here the running of KY converter, sun cell is given to the KY converter sun-PV cells produce energy at once with the aid of converting the sun energy into electricity that is acquired from sun cell is given to the KY converter which is the combination of boost converter is used to setup the dc voltage.The dc voltage is fed to the DC motor.Thus, it can be used for low power applications.For supplying the load properly, the power obtained often needs better DC-DC conversion.The fig. 14 shows the simulation model of the proposed system.The 36 volts is the input voltage given to the KY converter and gives the output voltage and output current of 50 volts, 5 A as per the design calculations and compared to the other converters, the voltage ripple and the current ripple is very small.The voltage ripple is 0.004 and the current ripple is 0.0002.The output of the KY converter circuit is sent directly to the load.Continuous output with reduced ripple count and better transient response can be achieved.The output of the KY converter circuit is given directly to the load.A continuous output with reduced ripple counts and a better transient response can be obtained.We have implemented the closed loop of KY converter using PID control in our project which has been fed to the DC motor.Hence for implementation in low power applications a ripple free output with comparatively high efficiency can be obtained.

Conclusion
For extensive variable-speed drives, direct current motors with variable characteristics are used.A high starting torque is provided by a DC motor and it is also possible to obtain speed control over a wide range.Conventionally DC motors are suitable for various applications as their characteristics are highly efficient but in our paper, to be used for low power applications it is used in combination with KY converter.In modern society, portable electronic devices such as: mobile phones, laptops and digital still cameras widely used DC-DC converters.In order to convert the battery voltage into different voltage domains.In most instances, For power supply applications using low Voltage battery, it is necessary to uplift from low voltage to high voltage, thus a boost converter is usually applied, but with a pulsating output current leading to a large voltage ripple.The converter has many advantages such as no ripple current, low output ripple and good load transient response, which can eliminate the problems of the boost converter, so the KY converter can be used at instead of the boost converter, which has more advantages over good output response for conventional boost converters when operating in continuous conduction mode.The solar panel is used to supply direct current, and this direct voltage is stored in the battery.To increase the voltage level, the voltage thus stored in the battery is then supplied to the converter KY.The output of the converter circuit KY is then directly supplied to the load.Thus, a continuous output with a reduced number of ripples can be obtained, and a better transient response can be obtained.

Figure 4 .Figure 5 .
Figure 4. Boost ConverterThe fig.4shows the boost converter.When the switch is turned ON diode won't conduct makes the circuit as short circuit.When the switch is turned OFF the diode starts conducting and makes the circuit as short circuit.The voltage is stepped up in this converter.The output DC voltage is greater than the input DC voltage for the boost converter.[5]

Figure 11 .
Figure 11.Simulation Model of KY Converter

Figure 15 .
Figure 15.Simulation Output characteristics of DC motor

Table 2 .
Design parameters of proposed systemTable2shows the design parameters of the proposed system.The boost converters currently used for helicopter control in wind and solar systems offer response characteristics that can be improved by implementing a KY converter instead of a boost converter.In this topology, the implementation of the KY converter is done in MATLAB/SIMULINK with respect to open loop and PID controllers.Increase the input voltage of the PV panel to an appropriate level.

Figure 14 .
Simulation Model of Proposed System