water power peer review

1 | Program Name or Ancillary Text eere.energy.gov

Water Power Peer Review

Design of Submersible Generator for MHK Rob Cinq-Mars, President

Free Flow Energy, Inc.(800) 928-0435; Rob@FreeFlowEnergy.com6 September 2011

Project Number: DE-EE0004567

2 | Wind and Water Power Program eere.energy.gov

Purpose, Objectives

The design of a submersible generator – key features:– designed by motor/generator industry professionals– work with multiple turbine styles– critical subassembly of current energy conversion systems

Objectives:• accelerate MHK• improving performance• lowering cost, and • improve operation and maintenance

Project Team

Industrial Partners

Technical Approach - Tasks

1. Assess resources tidal and river for:– proper sizing– form factor– power rating– ambient operating conditions.

2. Determine appropriate topology

3. Electromagnetic circuit design

4. Mechanical design

5. Investigate Manufacturing Requirements

6. Cost Analysis

7. Commercialization and future research

Technical Approach – Key Issues

• MHK Generators - where wind generators were in ‘70s

• Eliminate gearbox (Rim Mount Design)

• Get topology, sizing, power and form factor right

• Components designed/manufactured by industry

• Work with multiple turbines

• Design for harsh marine environment

• Coupling method

Schedule & Budget

Schedule• Initiation date:11/1/2010• Planned completion date: 10/31/2011• Design Completed, report published, paperwork

complete

Budget: • On schedule, on budget, additional cost share provided

Budget History

FY2009 FY2010 - FY2011

DOE Cost-share DOE Cost-share

N/A N/A $160K $54K

Project - Preliminary

• Differences between renewable and conventional generation• Appreciate difference between power, energy and nameplate capacity• Differences between tidal and inland stream flows• Design for common siting conditions not extreme / rare• Lessons learned from wind• Many different turbine styles, sizes, & stages of development• Review and understanding of MHK state of art• Understanding of regulatory, permitting, siting• Acceptance of 35% efficiency• Baseline estimate of “realistic” siting conditions

Resource Assessment - Tidal

What’s Realistic?

Resource Assessment - Area

Area & # Turbines to Generate 1 MW Assumes 35% eff (Gorlov)

Resource Assessment – Distribution & Area

UK Current Predictions

Tacoma Narrow Currents

Maine, Washington, and AK Velocity Frequency Histograms

Most recently – Georgia Tech / DOE Model, Mid Atlantic Currents

Mid – Atlantic Depths

Resource Assessment - Inland

Resource Assessment – Inland

chan_discharge Channel Flow The channel discharge in cubic feet per second

chan_width Channel Width The channel width in feet

chan_velocity Channel Velocity The mean velocity in feet per second

chan_area Channel Area The channel area in square feet

chan_depth (calculated) Channel Depth Average depth in meters

USGS Field Descriptions

Resource Assessment - Inland

Channel Velocity (mps)

Channel Area - Inland

USGS Inland Data – Channel Area (m^2)

Channel Depth - Inland

Channel Discharge CMS

Resource Assessment Cont.

Depth: 10 – 30 m (Top: Nav Clearance, Bottom: Permitted Sites)Salinity: 35 pptTemp: 35-90 F, 2-32 C

Analysis of turbines

Proprietary data was shared with FFE based upon completed NDAs. Data included CAD, test data, estimated torque / speed, TSR, etc.

This data was used to design a generator with a 2 meter diameter rated at 20 kW to connect to a 3m x 7m GHT, or an equivalent FloDesign turbine which presents a 5 m diameter to the flow. This is approximately 21 m^2 in cross section.

Comparable dynamic performance…

Selection of appropriate topology

Induction or Synchronous?(Field winding not reasonable)

AF, RF, or TF?Gearbox for speed?

(Rim mount)Iron core or coreless (magnet use and detent torque)Pole Count: more poles more voltage more power (balancing act)Cost and manufacturabilitySelection: RFPM Synchronous as wind is evolving to.

Gearbox Issue

Shaft seals are an issue, bow wakes, velocity fluctuations we selected rim mount speed enhancement with 2 m diameter

Generator Topology AF or RF

What others do…

Air core?

Transverse Flux?

Weight reduction?

Increased magnet use

What others do…

SmartMotor

Claims: concentrated windings, higher fill factor, higher efficiency

It appears from the description that this generator uses large gauge wire, hand inserted.

What others do…

VIEG – Variable Input Electrical Generator

This appears to be a “stacked generator.” They appear to be dynamically connecting windings in series at low speed and parallel at high. This appears to be quite costly, like purchasing multiple generators for one site.

Our generator

Radial flux, permanent magnet, synchronous, three phase, rim mount (2 meter diameter, 20 kW in 2 m/sec flow)

A conventional, buildable, cost effective approach capable of coupling to multiple turbine designs. The design leverages established and simple

manufacturing processes.

Concept with Single GHT

Concept with Double GHT

Concept with Ducted In-flow turbine

Electromagnetic Circuit Design

Electromagnetic Circuit Design (cont)

Mechanical Design – Segment Lam

Mechanical Design – Segment Core

Mechanical Design - Magnets

Mechanical Design - Rotor

Mechanical Design - Other

Mechanical Design – Winding Diag.

Other Work Completed

Cost Analysis

Manufacturability

Tooling and Fixturing Requirements

Protective Coatings

Refer to Final Report

Conclusion

Delivered what was proposed…

the design of a submersible generator capable of coupling to multiple turbine styles, designed by motor/generator design engineers specifically for MHK

Needed:

Turbines to move closer to production

Diversions to accelerate flow

A greater indication of commercial viability

Moving Forward – Latest News…

Moving forward: embracing diversions

http://www.youtube.com/watch?v=hEnANV8laRU

water power peer review

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water power peer review