Electrification in Ship

2021 ◽  
Vol 9 (VI) ◽  
pp. 3781-3785
Author(s):  
Dr. Shaik Abdul Ahad
Keyword(s):  
Output Voltage ◽  
Engine Block ◽  
Step Down

In ships electricity is generated by the use of alternators. These alternators are equipped with an inbuilt rectifier which gives a DC output. Depending on the speed of the alternator the output voltage will be either 48-volts or 12-volts. Now the ship generally has two different batteries with 48-volts (housing battery’s) and 12-volts (Engine block battery’s). These batteries are responsible for providing power for both engine block and for housing purpose as well. This battery’s need to be charged. When the alternator is providing a output voltage of 48-volts the 48-volts will be directly charged and a buck convertor is used to step down the voltage from 48-volts to 12-volts and charge 12-volts battery’s. when the alternators are providing a voltage of 12-volts the 12-volt batteries are directly charged and if they charge fully the the boost convertor is used to step-up the voltage and charge the 48-volts battery. Depending on speed of the alternator the output voltage varies to defined values and based on these either boost or buck operation takes place.

scholarly journals Novel Step-Down DC–DC Converters Based on the Inductor–Diode and Inductor–Capacitor–Diode Structures in a Two-Stage Buck Converter

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1131 ◽  
Author(s):  
Mauricio Dalla Vecchia ◽  
Giel Van den Broeck ◽  
Simon Ravyts ◽  
Johan Driesen
Keyword(s):  
Output Voltage ◽  
Buck Converter ◽  
Switching Frequency ◽  
Two Stage ◽  
Voltage Level ◽  
Multiple Strategies ◽  
Power Electronics Converters ◽  
Load Demand ◽  
Duty Cycles ◽  
Step Down

This paper explores and presents the application of the Inductor–Diode and Inductor-Capacitor-Diode structures in a DC–DC step-down configuration for systems that require voltage adjustments. DC micro/picogrids are becoming more popular nowadays and the study of power electronics converters to supply the load demand in different voltage levels is required. Multiple strategies to step-down voltages are proposed based on different approaches, e.g., high-frequency transformer and voltage multiplier/divider cells. The key question that motivates the research is the investigation of the aforementioned Inductor–Diode and Inductor–Capacitor–Diode, current multiplier/divider cells, in a step-down application. The two-stage buck converter is used as a study case to achieve the output voltage required. To extend the intermediate voltage level flexibility in the two-stage buck converter, a second switch was implemented replacing a diode, which gives an extra degree-of-freedom for the topology. Based on this modification, three regions of operation are theoretically defined, depending on the operational duty cycles δ2 and δ1 of switches S2 and S1. The intermediate and output voltage levels are defined based on the choice of the region of operation and are mapped herein, summarizing the possible voltage levels achieved by each configuration. The paper presents the theoretical analysis, simulation, implementation and experimental validation of a converter with the following specifications; 48 V/12 V input-to-output voltage, different intermediate voltage levels, 100 W power rating, and switching frequency of 300 kHz. Comparisons between mathematical, simulation, and experimental results are made with the objective of validating the statements herein introduced.

A HIGH EFFICIENCY ADAPTIVE CURRENT MODE STEP-UP/STEP-DOWN DC–DC CONVERTER WITH FOUR MODES FOR SMOOTH TRANSITION

2014 ◽  
Vol 23 (07) ◽  
pp. 1450097 ◽  
Author(s):  
YANZHAO MA ◽  
SHAOXI WANG ◽  
SHENGBING ZHANG ◽  
XIAOYA FAN
Keyword(s):  
Transient Response ◽  
Output Voltage ◽  
High Efficiency ◽  
Current Mode ◽  
Smooth Transition ◽  
Maximum Efficiency ◽  
Cmos Process ◽  
Voltage Ripple ◽  
Transition Modes ◽  
Step Down

This paper presents a current mode step-up/step-down DC–DC converter with high efficiency, small output voltage ripple, and fast transient response. The control scheme adaptively configures the converter into the proper operation mode. The efficiency is improved by reducing the switching loss, wherein the converter operates like a buck or boost converter, and conduction loss, wherein the average inductor current is reduced in transition modes. The output voltage ripple is significantly reduced by incorporating two constant time transition modes. A fast line transient response is achieved with small overshoot and undershoot voltage. An adaptive substrate selector (ASS) is introduced to dynamically switch the substrate of PMOS power transistors to the highest on-chip voltage. A lossless self-biased current sensor with high-speed and high-accuracy is also achieved. The proposed converter was designed with a standard 0.5 μm CMOS process, and can regulate an output voltage within the input voltage ranged from 2.5 V to 5.5 V. The maximum load current is 600 mA, and the maximum efficiency is 94%. The output voltage ripple is less than 15 mV in all operation modes.

scholarly journals Stability Analysis in Positive Output and Negative Output DC to DC Converters Used in Renewable Energy Applications

2019 ◽  
Author(s):  
Maheswari Ellappan ◽  
Kavitha Anbukumar
Keyword(s):  
Renewable Energy ◽  
Stability Analysis ◽  
Output Voltage ◽  
Monodromy Matrix ◽  
Period Doubling ◽  
Current Mode ◽  
Power Converter ◽  
Control Technique ◽  
Step Down ◽  
The Stability

The renewable energy source plays a major role in the grid side power production. The stability analysis is very essential in the renewable energy converters. In this paper the bifurcation is analyzed in ZETA converter and Continuous input and output(CIO) power Buck Boost converter. The ZETA converter gives positive step down and step up output voltage and the CIO power converter gives the negative step up and step down output voltage. These converters are used in the DC micro grid with renewable energy as the source. The current mode control technique is applied to analyze the bifurcation behavior and the reference current is taken as the bifurcation parameter. When the reference current is varied, both the converters loses its stability and it enters into chaotic region through period doubling bifurcation. The simulation results are presented to study the performance behavior of both the converters. The stability region of both the converters are determined by deriving the Monodromy matrix approach.

scholarly journals A Modified Topology of a High Efficiency Bidirectional Type DC–DC Converter by Synchronous Rectification

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1555
Author(s):  
Somalinga S S Sethuraman ◽  
KR. Santha ◽  
Lucian Mihet-Popa ◽  
C. Bharatiraja
Keyword(s):  
Energy Source ◽  
Output Voltage ◽  
High Efficiency ◽  
Storage Systems ◽  
Voltage Gain ◽  
Boost Converters ◽  
Hybrid Energy ◽  
Large Current ◽  
Synchronous Rectification ◽  
Step Down

A modified Topology to acquire high efficiency of a bidirectional method of DC–DC converter of non-isolated approach is proposed. The modified circuit involves four numbers of switches with their body diodes, passive elements as two inductors as well as a capacitor and the circuit arrangements double boost converters to progress the voltage gain. The input current of the proposed topology divided amongst the two dissimilar values of inductors produces greater efficiency. In the step-down mode, an apparent lessening in voltage gain and also enhanced efficiency can be realized in the recommended system by expending a synchronous rectification. The modified topology shields the technique for presentation of easy control configurations and is used for truncated output voltage with a large current of energy storage systems in the renewable applications as well as hybrid energy source electric vehicle applications. The simulation of the projected structure has been conducted through MATLAB/Simulink software and has been corroborated through a 12 V/180 V, 200 Watts experimental prototype circuit.

An Effort to Reduce Voltage from DC to DC Converter with a Monolithic Circuit Based on IC LM 2596

2019 ◽  
Vol 16 (12) ◽  
pp. 5162-5165
Author(s):  
Cekmas Cekdin ◽  
Zainuddin Nawawi ◽  
Muhammad Faizal
Keyword(s):  
Output Voltage ◽  
Cooling System ◽  
Electronic Devices ◽  
Input Voltage ◽  
High Heat ◽  
Output Current ◽  
Voltage Range ◽  
Step Down

Step down regulator is a device that can reduce the more significant input voltage to a smaller output voltage. The output is stable and well regulated, although the voltage fluctuates in the recommended input voltage range. In the system using IC LM 2596, the input voltage is 40 Volt dc, and the output voltage is 30 Volt dc. The output current of 15 amperes is applied to charge a 100 Ampere hour (Ah) battery on an inverter system installed and integrated with other electronic devices. The step-down IC LM 2596 will be stable at the output current below 15 Ampere. It is especially stable at load currents from 13.2 Ampere to 14.57 Ampere. In order for the current not to shrink, a good cooling system must be designed to dispose of heat on the IC LM 2596. Because the high heat greatly affects the output current on the IC LM 2596.

State Feedback Controller Using Pole Placement Method for Linear Buck Converter to Improve Overshoot and Settling Time

2015 ◽  
Vol 793 ◽  
pp. 211-215
Author(s):  
Mazwin Mazlan ◽  
Noor Haqkimi ◽  
Chanuri Charin ◽  
Nur Fairuz ◽  
Nurul Izni ◽  
...  
Keyword(s):  
Output Voltage ◽  
State Feedback ◽  
Input Voltage ◽  
Buck Converter ◽  
Pole Placement ◽  
Electronic Circuits ◽  
Solution Approach ◽  
Placement Method ◽  
Lqr Controller ◽  
Step Down

Switched mode DC-DC converters are electronic circuits which convert a voltage from one level to a higher or lower level voltage. This paper presents a new solution approach to controller and observer controller of DC-DC Buck converter. The designs in this paper of DC-DC Buck converter is input voltage 20V step down to 12V output voltage. For control the system simulation investigation into development of controller and observer controller using MATLAB Simulink® software. The simulation develops of the controller and observer controller with mathematical model of DC-DC Buck converter. This paper also providing LQR controller to compare the performance of the system. Finally, the performance output voltage of DC-DC Buck converter is analyzed in terms of time response, overshoot and steady state error.

scholarly journals A Detection Circuit for Improving the Unloading Transient Performance of the COT Controller

Electronics ◽  
2021 ◽  
Vol 10 (19) ◽  
pp. 2333
Author(s):  
Xi Zhang ◽  
Tianshi Wang ◽  
Bocheng Bao
Keyword(s):  
Transient Response ◽  
Output Voltage ◽  
Buck Converter ◽  
Control Technique ◽  
Time Interval ◽  
Transient Performance ◽  
Load Step ◽  
Light Load ◽  
Detection Circuit ◽  
Step Down

Fast load transient response and high light-load efficiency are two key features of the constant on-time (COT) control technique that has been widely used in numerous applications, such as for voltage regulators and point-of-load converters. However, when load step-down occurs during an on-time interval, the COT controller cannot respond until the COT interval expires. This delay causes an additional output voltage overshoot, resulting in unloading transient performance limitation. To eliminate the delay and improve the unloading transient response of the COT controller, a load step-down detection circuit is proposed based on capacitor current COT (CC-COT) control. In the detection circuit, the load step-down is monitored by comparing the measured capacitor current with the preset threshold voltage. Once the load step-down is monitored, the on-time is promptly truncated and the switch is turned off. With the proposed detection circuit, the CC-COT-controlled buck converter can monitor the load step-down without any delay and obtain less output voltage overshoot when the load step-down occurs during the on-time interval. PSIM circuit simulations are employed to demonstrate the feasibility of the detection circuit.

scholarly journals Implementation of Fuzzy Logic Controller for DC–DC step Down Converter

2021 ◽  
Vol 10 (8) ◽  
pp. 109-112
Author(s):  
Shaik Gousia Begum ◽  
Syed Sarfaraz Nawaz ◽  
G. Sai Anjaneyulu
Keyword(s):  
Fuzzy Logic ◽  
Output Voltage ◽  
Fuzzy Logic Controller ◽  
Supply Voltage ◽  
Buck Converter ◽  
Buck Converters ◽  
Major Drawback ◽  
Dc Voltage ◽  
Overall Efficiency ◽  
Step Down

This paper presents the design of a Fuzzy logic controller for a DC-DC step-down converter. Buck converters are step-down regulated converters which convert the DC voltage into a lower level standardized DC voltage. The buck converters are used in solar chargers, battery chargers, quadcopters, industrial and traction motor controllers in automobile industries etc. The major drawback in buck converter is that when input voltage and load change, the output voltage also changes which reduces the overall efficiency of the Buck converter. So here we are using a fuzzy logic controller which responds quickly for perturbations, compared to a linear controllers like P, PI, PID controllers. The Fuzzy logic controllers have become popular in designing control application like washing machine, transmission control, because of their simplicity, low cost and adaptability to complex systems without mathematical modeling So we are implementing a fuzzy logic controller for buck converter which maintains fixed output voltage even when there are fluctuations in supply voltage and load. The fuzzy logic controller for the DC-DC Buck converter is simulated using MATLAB/SIMULINK. The proposed approach is implemented on DC-DC step down converter for an input of 230V and we get the desired output for variations in load or references. This proposed system increases the overall efficiency of the buck converter.

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