1. DC bus for photovoltaic power supplying computing loads
Vincent Flaherty
4th year Electronic Engineering

2. Project Aims
The aim of this project is to investigate if the efficiency of power delivered from a domestic PV installation can be improved by supplying such DC loads through a DC bus instead of through an AC grid connection.

3. Progress to Date Research of PV systems.
Review of power consumption of different loads.
Review of PV inverters.

4. Progress to Date
Investigation and PSPICE simulation of AC/DC converter.
Full Wave Rectifier
Flyback Converter

5. PV systems PV modules convert sunlight to electricity.
Made from semiconductor materials.
General efficiency (6 – 20%)
An ideal solar cell can be modelled using a current source in parallel with a diode

6. [Figure taken from cnet.com]
Power Consumption
The average power consumption for a range of electrical devices which drive DC loads.
[Figure taken from cnet.com]
Appliance
Consumption
LCD Television
213 Watts
Plasma Television
339 Watts
Playstation 3
197 Watts
Xbox 360
187 Watts
Average PC
78 Watts
Nintendo Wii
19 Watts
Wireless Router
7 Watts

7. PV Inverters Used to change DC electricity to AC electricity.
2 main types used with PV systems.
Grid-tie inverters.
Battery backup inverters
Solar inverters use procedures such as MPPT to deal with the PV array.

8. MPPT DC/DC converter functions as optimal load for a PV cell.
MPPT is used by solar inverters to get the most power possible from a PV array.
Can be used with or without batteries.
The benefits of MPPT regulators are greatest during cold, hazy or cloudy weather.

9. Fullwave Rectifier Used to convert AC to DC.
Most simple method of conversion.
Quite easily simulated using PSPICE.

10. Fullwave Rectifier

11. Flyback Converter
DC/DC converter with isolation between input and output.
Very similar to Buck-Boost converter.
Voltage ratios can be multiplied due to turns in transformer.
Can operate over a wide range of inputs.

12. Flyback Converter

13. Major Challenges Finding circuit schematic for AC/DC adapter.
Effective simulation of Flyback converter.

14. Next Steps Finalisation of Flyback converter simulation.
Investigation and simulation of other DC/DC converters. (Buck, Boost etc.)

15. Questions?