1

Generator Control that is Ideal for Windmills

Converter

• Increases available voltage and Power to 150%- Generator could be 1/3rd smaller

• Bearing currents are eliminated• Slot insulation reduced by a factor 1.73• Higher efficiency (?)• Power Factor on the Utility-side is controllable• Increased Reliability due to Capacitor Elimination• SiC Ready

2

Research Activities(PhDs in the last 2 years)

1. 14/42-Volt Novel Bi-directional dc-dc Converters (Philip Jose, Nov 2004)

2. Doubly-Fed Induction Wind-Electric Generators (Ted Brekken, July 2005)

3. Robust Control and Fault Ride-Through of Wind-Electric Generators (Manoj Rathi, August 2005)

4. Hybrid Soft-Switching DC-DC Converters (Rinkle Jain, January 2006)

5. Synchronous-Reluctance Drives for Flywheel Storage (Todd Begalke, February 2006)

6. Switched-Reluctance Motor Drives (Nitin Bhiwapurkar, June 2006)

7. Digitally-Controlled Current-Source Multi-Output Converters (Som Chakroborty Sept 18, 2006)

3

Educational ActivitiesTextbooks

Laboratories

Reforming Undergraduate Education in Electric Energy Systems - 1.23 M$, Aug 2006 – Aug 2011

Fall 2006 Enrollments: Drives – 130, Power Systems – 76, Power Electronics – 94

4

Utility

InductionGenerator

WindTurbine

AC

DC

DC

AC

Wound rotor Induction Generator

Generator-sideConverter

Grid-sideConverter

Wind Turbine

AC

DC

DC

AC

Wound rotor Induction Generator

Generator-sideConverter

Grid-sideConverter

Wind Turbine

5

ConverterConverter

6

Figure 1-19 Load-side converter in a voltage-source structure.

conv1 conv2

controller

utility Load

conv1 conv2

controller

utility LoadUtilityWind Generator

Conventional System

Problems with the Storage Capacitor:1. Weight and cost

2. Reliability

3. Inrush Current at switch-on

4. Not suitable for high temperature operation

5. Difficult to integrate Motor and Power Electronics

7

Press Release 2006- 110 kVA SiC-based Inverter

by Kansai Electric and CREE

- 50% less conversion losses compared to Si inverters

Advantages of SiC Devices- Lower Losses; Higher Efficiency- High Temperature; Compact Design

8

Utility

Open-Ended Generator

Solid-State Switches(no capacitor or inductor)

Proposed Topology

9

MC Matrix Converter≡

1side2side

10

Open-Ended AC Generator with Matrix Converters

Utility

Open-EndedGenerator MC Matrix Converter≡

1MC2MC

0.5 + 0.5 =NewMath 1.5

11

Simulation Results:Output Voltages and Currents

Fig .9b The output phase voltage averaged over every switch cycle and the output current.

12

Simulation Results:Input Voltages and Currents

Fig .9c The input phase voltage and the input phase current.

13

1emT pu=

,m fω0 0.5pu 1.0pu 1.5pu

1.5mV pu=

1.0mV pu=

proposed

proposed

conventional

conventional

Capability Curves with Common Mode Voltages Eliminated

14

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

1990 1995 2000 2005

USD/A

1200 V IGBTs

Power Semiconductor Price Trends

Copper Prices

Drivers

New technologies

Design for manufacturing

High volume techniques

Drivers

New technologies

Design for manufacturing

High volume techniques

15

Major Applications

16

DoD Electric Power System Applications

Electric Warship

More Electric Aircraft

Electromagnetic Arrestand Launch

Reconnaissance, Surveillance, Targeting Vehicle (RSTV)

Pulse Power Weapons & High Power

Sensors

TE - 6

17

• Increases available voltage and Power to 150%- Generator could be 1/3rd smaller

• Bearing currents eliminated• Slot insulation reduced by a factor of 1.73• Higher efficiency (may be?)• Utility-side power factor is controllable• Increased Reliability due to Capacitor

Elimination• SiC Ready

Simultaneous Benefits

18

201800

1.5 ,41.0 ,

-pole60Hz

MWV PU=

Converter

60Hz690V 690V

1.0 ,61.5 ,

-pole90Hz

MWV PU=

Direct DriveConverter