DC bus for photovoltaic power supplying computing loads Vincent Flaherty 4th year Electronic Engineering
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.
Progress to Date Research of PV systems. Review of power consumption of different loads. Review of PV inverters.
Progress to Date Investigation and PSPICE simulation of AC/DC converter. Full Wave Rectifier Flyback Converter
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
[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
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.
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.
Fullwave Rectifier Used to convert AC to DC. Most simple method of conversion. Quite easily simulated using PSPICE.
Fullwave Rectifier
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.
Flyback Converter
Major Challenges Finding circuit schematic for AC/DC adapter. Effective simulation of Flyback converter.
Next Steps Finalisation of Flyback converter simulation. Investigation and simulation of other DC/DC converters. (Buck, Boost etc.)
Questions?