General Purpose Power Electronic Converter

The goal of the project is to make the converter can increase the efficiency and be more cheap.

Background
Converters are a commonly used device within many electronic systems that allow the voltage of the device to operate in an area with a different voltage. This functionality is increasingly important in many technologies today since electronic devices often contain multiple sub-circuits where each circuit may have different voltage requirements than each other to include the main power supply. A well-known example of this is within portable electronic devices, such as cellphones, tablets, and laptop computers.

Desired Goals
For our project, the design goal is to develop a converter system that utilizes four traditional converters and combines their outputs to push a higher, more efficient output while lowering the cost of high power converter system; ideally four, 60 kW converters as a single, 0.25 MW system.

Project Specifications
To implement the desired specifications into such a system, it was determined that by developing a lower power equivalent of the system, the control scheme of the system could be created and then scaled-up so that the desired goal could be attained. In agreeance with the client, the new project specifications are as follows:
 * • Input: range dependent on available power sources – 12 VDC to 36 VDC
 * • Output: fixed at a single voltage of 24 VDC
 * • Must have at least four traditional converter modules
 * • Efficiency must be greater than 94.0 %
 * • Optional: Small System preferred.

Project learning plan

 * 1.	We need to investigate the different types of DC-DC converters to know their characteristics.


 * 2.	We need to build a simulation schematic of a single converter module


 * 3.	We need to build a simulation schematic of an integrated converter module.


 * 4.	We need to find the relationship between efficiency and load currents for control algorithm from the simulation schematic.


 * 5.	Develop the software to automate the optimization function of the combined converter modules


 * 6.	Meanwhile, we need to design a PCB for our schematic. Also, we need to make a specific budget to buy components.


 * 7.    We need to build the PCBs and test them step by step.


 * 8.    When the hardware is finished. Hardware builder will give these PCBs to Control Algorithm designer to improve his Algorithm.

Circuit Design
''' Figure 1.Circuit of Forward-Converter

Design Requirement

 * •	Minimum Input Voltage Value: Vinmin = 12 V
 * •	Maximum Input Voltage Value: Vinmax=36V
 * •	Output Voltage Value: Vout=24V
 * •	Pout=100W  Efficiency >=94%

Important values Calculation

 * •	Output Current: Iout=Pout/Vout=4.176 A Rload=Pout/Iout2 = 5.76Ω

Np-s= 1/3 Remarks: on the schematic, the ratio transformer is 300u : 2.7m. When we use set transformers in LTspice, (1:x) must be transformed into (1:x2). VOUT(TARGET) = 24V    Rset = 33333.33Ω Vset= Rset x 20uA= 0.6667V

Duty cycle
D=（12 x 0.6667V）/24V =  0.33335

Soft-start
Set tss= 2ms ,Css= 50nFx(tss/1ms)=100nF

Frequency
Set Rt= 49.9kΩ  Frequency =200KHz

Feedback
R4/R5 = (24V/1.6)-1= 14 : 1

Secondary Part Component Value
⊿Vc = 0.24V, ⊿ iIx = 8.352A Lx, min = 9.579uH minimum Inductor value Cx, min = 27.69uF Minimum Capacitor value

Other Components Values
CDFILT: Np/Ns=1/3,    L1 = 50uH,   CL=60uF  CDFILT,min=9.1287x1010F Set |Vref|=1.6V  Cc=4.7nF，Rsense= 0.0025 Ω    RZ,min = 3995Ω

Simulation Results
..........................................................................figure(1). simulation result value of every component.............................................................................................



the picture shows output voltage that the x-coordinate is time, and the y-coordinate is voltage,and it is almost getting close to 24V that is what we want to achieve purpose. ..................................This is our PCB board................................

Budget

 * Budget

Contract

 * Contract

Meeting Minutes

 * meeting minutes

Design Review Presentation

 * Presentation 1
 * Presentation 2

Final expo

 * expo