UNIVERSITY OF PUERTO RICO - MAYAGUEZ

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UNIVERSITY OF PUERTO RICO - MAYAGUEZ
Impact of Renewable Energy Sources
Vladimir Oliveras Antón G. Méndez
Students Dr. Efraín
ONeill Advisor
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OBJECTIVES

• Determine the impact of alternate energy sources
  on power systems
• Study grid interconnection issues and standards
• Modeling and development of tools to quantify
  their impact
• Establish a small PV system for validation of the
  theoretical work and testing

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METHODOLOGY
Seminars Power Electronics
Renewable Sources
Literature Review
Publications
IEEE Standards
Establishment
Modeling Simulations
of a small
PV system
Lab Practices Demonstrations
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POWER ELECTRONICS

• Convert energy from one form to another in order
  to better suit the load
• Market emergence because of advances in
  semi-conductor fabrication technology
• Enables other technologies
• Energy efficiency, reliability, weight and cost
  should be taken into account

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POWER QUALITY

• It measures, classifies, and analyzes power
  disturbances
• It may help improve system efficiency
• Affected by continuous switching of power
  electronics devices
• A good understanding will help improve power
  problems

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DISTRIBUTED GENERATION

• Occurs when generation sources are located at or
  near loads
• Helps diminish the amount of power taken from the
  grid supply, if any
• Can provide power to the grid when the power
  output exceeds the demand

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RENEWABLE POWER SYSTEMS

• Wind turbines and PV systems are the most widely
  studied for applications
• Require a power electronics interface in order to
  connect them to the electrical grid
• These devices introduce undesired disturbances,
  which affect the power quality
• Harmonics, flicker, sags and swells are some of
  these disturbances

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Typical PV Interface
DC-DC Converter
PV Array
Energy Storage
Inverter
Load
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Modified Square Wave Inverter
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Voltage and Current Waveforms
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Actual system

• PV cells capacity of 106 watts, 12 volts
• Inverter output capacity of 1500 watts, 115 volts
  RMS

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Pros and Cons of a Modified Square Wave Inverter

• Suitable for most of the typical loads
• electrical tools
• incandescent lights
• domestic appliances
• Not good for noise sensitive equipment
• medical equipment
• sensitive industry processes

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Utility vs. Inverter
Current Waveforms
Current THD
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Emissions Savings
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Conclusions

• Alternate Energy Sources provide efficient energy
  for specific applications
• Initial Cost and other economical issues need to
  be taken into account
• Energy conversion degrades the quality of power
• This degradation includes the injection of
  harmonics to the electric power grid

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Conclusions (cont)

• Harmonics induce an improper equipment
  functionality
• Overloading is a possible situation for
  stand-alone systems, resulting in the
  non-functionality of the equipment
• Environmental emissions are reduced when using
  renewable energy systems
• Consciousness for energy savings

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Laboratory demonstration

• Integration of system developed into power
  electronics and power quality courses
• Energy conversion
• Inverter performance
• Harmonic injection
• System reliability
• Grid Interconnection Issues

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BENEFITS FOR THE STUDENT

• Exposure to problems where engineering decisions
  play a key role
• Study of power electronics, power quality, power
  systems and economics
• Search in professional journals and conference
  publications
• Development of technical writing and presentation
  skills