Dc bus for photovoltaic Dc bus for photovoltaic power supplying power supplying computing loadscomputing loads

44thth year Electronic year Electronic EngineeringEngineering

Michael ikerionwuMichael ikerionwu

IntroductionIntroduction

• Most renewable sources of electrical Most renewable sources of electrical energy feed into an AC grid before energy feed into an AC grid before being applied to supply different being applied to supply different electrical loadselectrical loads

• For example DC power produced by For example DC power produced by domestic photovoltaic(PV) panels domestic photovoltaic(PV) panels feeds into the grid through AC feeds into the grid through AC inverter.inverter.

AimsAims

• To investigate if the efficiency of To investigate if the efficiency of power delivered from a domestic PV power delivered from a domestic PV installation supplying DC loads (such installation supplying DC loads (such as computer or lighting led etc) can as computer or lighting led etc) can be improved by supplying such DC be improved by supplying such DC loads through a DC bus instead of loads through a DC bus instead of through an AC grid connection.through an AC grid connection.

MilestonesMilestones

Milestone1Milestone1Review of domestic PV systems.Review of domestic PV systems.

Determine the power consumption of a range of DC loads.Determine the power consumption of a range of DC loads.

Determine the efficiency of power conversion from the AC grid to a typical load.Determine the efficiency of power conversion from the AC grid to a typical load.

Milestone 2Milestone 2Investigate standard DC/DC topologies for the chosen load.Investigate standard DC/DC topologies for the chosen load.

Milestone 3Milestone 3Build and test a standard DC/DC solution to illustrate the highest level of efficiency possible.Build and test a standard DC/DC solution to illustrate the highest level of efficiency possible.

Milestone 4 Milestone 4 Design DC/DC converter for solar panel to DC bus conversion.Design DC/DC converter for solar panel to DC bus conversion.

Milestone 5Milestone 5Build and test a DC/DC stage to demonstrate improved efficiency over a range of source and load conditions.Build and test a DC/DC stage to demonstrate improved efficiency over a range of source and load conditions.

Work done so farWork done so far

• Reseach on PV systems e.g panel Reseach on PV systems e.g panel characteristics and equivalent circuit.characteristics and equivalent circuit.

• Looked at power absorbed by Looked at power absorbed by different DC loads such as tv’s, different DC loads such as tv’s, computers, laptop, PS3...etc.computers, laptop, PS3...etc.

• Maximum power point tracking point Maximum power point tracking point at which circuits gets its maximum at which circuits gets its maximum power.power.

Work done so far cont.Work done so far cont.

• Install PSPICE and get use to it.Install PSPICE and get use to it.

• Look at rectifier circuit in PSPICE.Look at rectifier circuit in PSPICE.

• AC to DC conversion.AC to DC conversion.

• Basically covering the first milestone.Basically covering the first milestone.

PV panel circuit and PV panel circuit and characteristiccharacteristic

Maximum point trackingMaximum point tracking

Health and safety issuesHealth and safety issues

• Test on power converters should only Test on power converters should only be performed under the supervision be performed under the supervision of a technician or project supervisor.of a technician or project supervisor.