UNIVERSITY OF WISCONSIN SYSTEM
In this project, we propose to utilize Lithium-Ion Capacitor (LIC) on the DC bus of a full four-
quadrant power conversion system utilizing an algorithm to (i) pull mechanical power surges off
the drivetrain and into the LIC for dispatch to the grid and (ii) support the grid and protect the
turbine during power system transients. The immediate benefit of the proposed topology is less
mechanical wear, higher efficiency and lower cost as well as improving power system transient
stability. The proposed topology requires that the target wind turbine have a double conversion
converter. This type of wind turbine system is experiencing a large growth due to the need for
more controllable systems. Example systems include GE 2.5MW, Siemens 2.3 and 3.6MW,
ABB 0.5MW through 5MW, Clipper 2.5MW and the majority of new small wind turbines. The
utilized energy storage device is an LIC manufactured by JM Energy Corporation, a subsidiary
of JSR Corporation. The main objective of this project to develop, model, design, optimize, build
a scaled down model, and characterize an integrated system of LIC energy storage and power
conversion system that extends mechanical operating life, provides higher power efficiency and
improved quality of output energy and power.
The participants will conduct the analytical studies, develop a simulation model of the proposed
integrated system control software, model the system, and build and test a scaled down model.
The industry participants will contribute by ensuring the relevance of the proposed technology,
verifying the proposed model for practical applications, and enhancing the solution method
based on their real wind energy experience. The analytical, modeling and simulation models will
be initially developed by university participants at the University of Wisconsin at Milwaukee
(UWM) with the support of the National Renewable Energy Laboratory (NREL) and industry
participants. The overall system characterization, analysis and design of the scaled-down system
emulator, and validation and testing will be performed by the help of industry participants.
NREL participants will support all the activities during conducting the research. Industry
participants will contribute on the project communications, power control and interface of the
LIC with the overall wind energy management system, and interface of the integrated system
with the utility grid. Industry participants will contribute on characterizing, adapting and
implementing LIC within this system. It should be noted that the process between academia and
the companies will be iterative and interactive.