A COMPACT 400W SINGLE PHASE INVERTER

Senior Design II

Mid-Semester Presentation

Single Phase Inverter Team Members

Team LeaderElectrical Engineer

• Control System Design• Power Electronics• Programming• Website

Electrical Engineer

• Output Filter Design• Hardware Implementation• Power Electronics

Electrical Engineer

• Output Filter Design• Programming• Enclosure• Website

Electrical Engineer

• Hardware Implementation• Enclosure• Control System Design

Christopher Burge

Michael Robertson

Johnny Reed

Bret Hariel

Faculty Advisor: Dr. Masoud Karimi

Outline

Problem Solution Technical Constraints Practical Constraints System Overview Design Refinements Testing Plan Packaging Timeline Questions

Example of an inverter used to connect a distributed resources to a load

Problem

Adaptability of system components to change in distributed resource system parameters

Solution

An inverter which is capable of accepting variable DC inputs

Technical Constraints Name Description

Voltage Regulation

The voltage must stay within a 10% range centered on 120V.

Efficiency This device must have an efficiency greater than 95%

Total Harmonic Distortion

The THD must be less than 5%

Power Rating The device must be able to deliver 400W

Input Voltage Range

The device must be able to output a voltage of 120V with an input range from 200 to 300VDC

Practical Constraints

Type Name Description

Environmental Enclosure The inverter enclosure must be weather proof from sun and rain.

Manufacturability Size The inverter must be compact and weight less than 25lbs.

System Overview

DC Source

Output Filter Load

Voltage Sensor

Microcontroller

Power Electronic

Circuit

Control to Power Isolated

Interface

Design Refinement

Improvements

Voltage Sensing Circuit DC Source Replacement

DC Source Replacement

Buck Converter VLA106-24151 DC/DC 24V to15V UA78L00 15V to 5V DC Regulator TLE2426 to obtain -15V DC

Buck Converter Purpose:

To supply power to all the elements that are not in the power electronic circuit

Challenge:

How to supply power to the MOSFET of the buck converter on start up

Solution:

Put a passive component circuit in parallel with the buck converter to supply microcontroller power

Schematic of Buck Converter

Additional DC/DC Regulators

Purpose:

To supply all power from a single source

VLA106-24151 DC/DC 24V to15V UA78L00 15V to 5V DC Regulator TLE2426 to obtain -15V DC

Voltage Sensor Circuit (old)

Problem

High power loss in the voltage divider and additional voltage buses

Voltage Sensor Circuit (new)

Solution

A sensor network that requires less power and a less diversity of voltage buses

Product Testing

Power Quality, Voltage Regulation, and Efficiency

Power Quality:

The THD must be less than 5%

Voltage Regulation:

The device must be able to output a voltage of 120V with a no more than a 10% deviance regardless of the load within our operating range

Efficiency:

This device must have an efficiency greater than 95%

Power Quality, Voltage Regulation, and Efficiency

Power Quality:

Using the Fluke 43B Power Quality Analyzer we will measure the total harmonic distortion

Voltage Regulation:

Using the Agilent DSOX302A4 Oscilloscope we will monitor the output voltage and compare it to a central tendency value of 120V

Efficiency:

Using the Fluke 43B Power Quality Analyzer we will measure the output power and compare it to the input power of the Sorensen XHR 600-1.7 DC source.

Voltage Regulation Load Expected

Output VoltageExpected THD

R = 600 120.35V 1.24%

R = 200 120.33V 1.43%

R = 150 120.35V 1.01%

R = 100 120.55V 1.93%

R = 250 120.28V 0.87%

R = 100, L = 250µ 120.54V 1.94%

R = 100, L = 500µ 120.54V 1.94%

R = 100, L = 1m 120.73V 2.83%

R = 100, C = 5µ 120.37V 1.29%

R = 100, C = 10µ 120.40V 0.5%

R = 100, C = 20µ 120.50V 1.54%

R = 100, C = 10µ, L = 500µ 117.88V 0.7%

Variable DC InputThe output voltage must stay within a 10% range centered on 120V.

Test Conditions:

Test 1: Vary the input power of the Sorensen XHR

600-1.7 DC source from 200V to 300V

Test 2: Vary the input power of the Sorensen XHR

600-1.7 DC source from 300V to 200V

Results: Output remains within voltage regulation

constraint

Max Power Rating

The device must be able to deliver 400W

Test Conditions:

Three 100Ω power resistors placed in parallel to give a total of 33Ω to draw 400W to the load

Results: Pass Fail

PCB&

Packaging

PCB

PCB Design Software Options:Cadence OrcadEagle

PCB Design Choice: Eagle 5.11 Professional

Customizable libraries and ease of making parts

PCB Schematic

Microcontroller

Interface Circuit

Power Electronic CircuitDC Source

Voltage Sensor

Load

PCB Layout

6”

10”

Enclosure Requirements

ManufacturabilityMust exceed 10”x 8”x 4”Must weigh less than 15lbs

EnvironmentalMust be NEMA 3R

Enclosure Options

12”x 10”x 5” 13.45”x 11.83”x 6.31”

8.25lbs $180

6lbs$86 [1] [2]

Timeline

January February March April

Voltage Feedback

Design Refinement

PCB Design

PCB Implementation

Enclosure

References[1] L-com Global Connectivity. 12X10X Inch 120 VAC Vented Weatherproof Enclosure. Available: http://www.l-com.com/item.aspx?id=31421

[2] Automation Direct. Premier (6in. X 6in. to 16in. X 14in.). Available: http://www.automationdirect.com/adc/Shopping/Catalog/Enclosures/Non-Metal_%28NEMA_4X_-a-_3R%29/Premier_%286_in._X_6_in._to_16_in._X_14_in.%29

A COMPACT 400W SINGLE PHASE INVERTER

Senior Design II

Mid-Semester Presentation

Questions?