Get More Power from Your Low Power Inverters

Technology #32995

Questions about this technology? Ask a Technology Manager

Download Printable PDF

Image Gallery
Photovoltaic cells
Categories
Researchers
Utsav Somani
Issa Batarseh, Ph.D.
External Link (www.cecs.ucf.edu)
Haibing Hu, Ph.D.
Charlie Jourdan
Ahmadreza Amirahmadi
Lin Chen
Qian Zhang, Ph.D.
Managed By
Andrea Adkins
Assistant Director 407.823.0138
Raju Nagaiah
Licensing Associate 407.882.0593
Patent Protection

Power Inverter Implementing Phase Skipping Control

US Patent 9,473,044

Hybrid zero-voltage switching (ZVS) control for power inverters

US Patent 9,484,840
Publications
Efficiency Improvement of Grid-Tied Inverters at Low Input Power Using Pulse-Skipping Control Strategy
IEEE Transactions on Power Electronics, December 2010, vol. 25, no. 12, pp.3129-3138
High Efficiency Dual Mode Current Modulation Method for Low Power DC/AC Inverters
IEEE Transactions on Power Electronics, June 2014, vol. 29, no. 6, pp. 2638-2642

A three-phase grid tied micro-inverter using controlled-based soft switching

A group of UCF researchers have developed a three-phase micro-inverter for low power applications, specifically batteries, solar panels, or fuel cells, with higher power density and efficiency. The entirely new control approach eliminates the need for expensive additional parts often required of hard switched inverters, such as SiC diodes or additional inductors, thereby increasing the power density and solving the light load efficiency problem. The three-phase grid tied power micro-inverter provides a three -level control scheme. Phase skipping control is one of the control schemes, and it selectively injects power through each phase, ensuring that the phases’ received power operates at a greater percentage of a load capacity, thus significantly improving the micro-inverter’s power efficiency. For the first time, a power inverter employs a hybrid zero-voltage switching (ZVS) current control technique for a switching inverter and soft switched controls which increases the switching frequency and yields higher power conversion efficiency. Now, achieve power conversion with lower costs, higher reliability, and higher power density.

Technical Details

Micro-inverter use has been limited to small scale, single phase residential and commercial PV installations. By extending the micro-inverter concept to large size PV installation where three-phase AC connection is used, advantages such as individual variable frequency maximum power point tracking (MPPT) to determine a switching frequency for a resonant power converter, redundant system architecture, ease of installation, removal of unreliable electrolytic capacitors, and less DC distribution losses can be gained. To make the idea of PV farm architecture based on three-phase micro-inverters feasible, a high efficiency, low cost, high reliability, high compact micro-inverter was designed and built. Invented three-phase micro-inverter can be used for any PV power plant, from small scale to proof applications for commercial building to large scale PV power plants.

Benefits

  • Peak efficiency of 96 percent
  • Eliminate the need of electrolytic capacitors
  • New MPPT method for resonant converter
  • New control based soft switching method with no additional cost or component
  • Solves the light load efficiency problem

Applications

  • Batteries
  • Residential solar systems
  • Commercial building solar systems
  • PV power plants
  • Fuel cells

Additional technology numbers: 32997, 32999, 33061