Page 64 - Energize July 2022

TECHNICAL

Experimental linear generator

DHE
The DHE engine is a twin opposed free piston engine which has been
developed for use as a range extender for EVs, but is also available in
a modular combination of several units to provide standby power.
There are several other manufacturers which have FPLGs at
pilot or pre-production stage such as Intelline, which offers 25 kW
modules which can be combined to produce higher power levels.
Most models use the central combustion zone or the opposed
twin piston principle.

The Stirling engine linear generator
The Stirling engine, which is commonly used for generation using Figure 13: DHE free piston engine generator (DHE)
waste heat, can be adapted to provide linear motion equivalent to
a free piston engine. Figure 15 shows a free piston Stirling engine
linear generator.

References
1. P Khatri: “Comprehensive review of a linear electrical generator
for ocean wave energy conversion”, IET Feb. 2020.
2. P Asmus: “Introducing linear generators to the DER landscape”,
Figure 14: Intelline MLG (Intelline)
Guidehouse Insights
3. X Wang: “A Review of the Design and Control of Free-Piston Linear
Generator”, Energies: 20 August 2018
4. A Raheem: “Review of free piston engine control literature”,
Alexandria Engineering Journal: Issue 61: 2022.
5. H Beighi: “Comparison of Radial and Halbach Array PMLSM by
employing 2-D Electromagnetic Finite Element Analysis”, JECEI,
Vol. 4, No.2, 2016.
6. J Kim: “Design and analysis of tubular permanent magnet linear
generator for small-scale wave energy converter”, Volume 7,
Issue 5.
7. A Elgebahly: “Optimized Design of PM Halbach Array Linear
Generator”, ASTES 2019.

Send your comments to rogerl@nowmedia.co.za Figure 15: Stirling engine free piston linear generator 3

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