General Purpose Power Electronic Converter
[[File:300pxcenteralt=]]  
Team Name  Powerpanda 
Duration  Spring 2018  Fall 2018 
Faculty Advisor 

Team Members 

Contents
Problem Definition[edit]
Background[edit]
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 subcircuits where each circuit may have different voltage requirements than each other to include the main power supply. A wellknown example of this is within portable electronic devices, such as a cellphones, tablets, and laptop computers.
Desired Goals[edit]
For our project, the design goal is to develop a converter system that utilizes 4 traditional converters and combines their outputs in order to push a higher, more efficient output while lowering the cost of high power converter system; ideally four, 60 kW converters as a single, .25 MW system.
Desired Specifications[edit]
 • input: ranged dependent on local power supplies available – 120 V  400 V Direct Current or Alternating Current (DC or AC)
 • Output: fixed set value as established based on need. – 120 V, 240 V 400 V DC or AC
 • Must have at least 4 traditional converter modules
 • Efficiency must be greater than 90.0 %
 • Although size is not specified, a smaller system would be preferred.
Project Design Procedure[edit]
 1. Investigate the different types of DC to DC (DC/DC) converters and their efficiencies.
 2. Build a simulation model of the converter module
 3. Build a simulation model of the combined converter modules.
 4. Determine the optimal operating points of the combined converter modules.
 5. Develop the software to automate the optimization function of the combined converter modules
 6. Build the combined converter modules
Project Specifications[edit]
In order 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 scaledup 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 4 traditional converter modules
 • Efficiency must be greater than 90.0 %
 • Optional: Small System preferred.
Designs[edit]
Circuit of Forward Converter
V1 is input voltage source.
L1 and L2 mean transformer.
RB068L152 is the diode that design by our team(this is the key component to keep efficiency high)
diode parameters:
1. BV=500
BV means breakdown voltage
2. N=0.35
N means emissive coefficient
3. Is=14.11n
IS means saturation current
4. Rs= 2.2m
Rs means series resistance
5. Cjo=40p
Cjo means zero bias junction capacitance
6. M=0.5
M means Nodal gradient factor
7. tt=25n
tt means crossing time
8. Iave=20
Iave means positive rated current
9. mfg means manufacturer
10. type means material, and we decide to use silicon
Rload is a load resistor.
R4 & R5 are feedback resistors
R3 is Rsense
R13, R14 and R15 are estimated values. UVLO and OVLO: the system undervoltage and overvoltage thresholds are programmed by a resistive voltage divider from Vin to UVLO and OVLO.
Rt controls frequency.
R1&C2 control duty cycle.
C3 means softstart input(this value is not very important)
the secondary part is the same as our ECE 320 textbook, so there is no detailed description. However, their calculation equations are given in the next part.
Calculation Part[edit]
Design Requirement[edit]
 • 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[edit]
 • Output Current: Iout=Pout/Vout=4.176 A Rload=Pout/Iout2 = 5.76Ω
Nps= 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[edit]
D=（12 x 0.6667V）/24V = 0.33335
Softstart[edit]
Set tss= 2ms ,Css= 50nFx(tss/1ms)=100nF
Frequency[edit]
Set Rt= 49.9kΩ Frequency =200KHz
Feedback[edit]
R4/R5 = (24V/1.6)1= 14 : 1
Secondary Part Component Value[edit]
⊿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[edit]
..........................................................................figure(1). simulation result value of every component.............................................................................................
the picture shows output voltage that the xcoordinate is time, and the ycoordinate is voltage,and it is almost getting close to 24V that is what we want to achieve purpose.
Project Budget[edit]
Pricing for Design[edit]
Team Information[edit]
Zhongdi Wang:
Major: Electrical Engineering 
EE
 
Xinyu Wu(kobe):
Major: Electrical Engineering 
EE  
Lyle Lair:
Major: Electrical Engineering Hobbies: Email: lair0186@vandals.uidaho.edu 
EE 
Document Archive[edit]
Other Documents[edit]
Content of meeting[edit]
 February 14 The First Meeting Minutes
 February 21 The Second Meeting Minutes
 March 1 The Third Meeting minutes
 March 22 The Forth Meeting minutes
 March 29 The Fifth Meeting Minutes
 April 3 The Sixth Meeting Minutes
 April 12 The seventh Meeting Minutes
 April 23 The Eighth Meeting Minutes