Starting of a free-piston linear engine-generator by mechanical resonance and rectangular current commutation

S.A., Zulkifli and M.N., Karsiti and A.R.A., Aziz (2008) Starting of a free-piston linear engine-generator by mechanical resonance and rectangular current commutation. In: 2008 IEEE Vehicle Power and Propulsion Conference, VPPC 2008, 3 September 2008 through 5 September 2008, Harbin.

[thumbnail of paper.pdf] PDF
Restricted to Registered users only

Download (12kB)
Official URL:


Starting a free-piston linear engine-generator (LG) involves reciprocating a freely moving piston-magnettranslator assembly between two oppositely placed engine cylinders for combustion to occur. The machine is operated as a brushless linear motor to produce the required motion. However, due to the very large peak compression force during starting, limited current rating of stator coils and insufficient motor force constant, it is not possible to push the translator end to end in a single stroke. A strategy is proposed which utilizes the air-spring quality of the engine cylinders prior to combustion. Energizing the coils with fixed DC voltage and open-loop, rectangular commutation of injected current, sufficiently high motoring force is produced to reciprocate the translator in small amplitudes initially. Due to repeated compression-expansion of the engine cylinders and constant application of motoring force in the direction of natural bouncing motion, the translator's amplitude and speed is expected to grow - due to mechanical resonance - to finally reach the required parameters for combustion. This work discusses the starting problem and its mechanical aspects for a specific LG configuration, builds a mechanical model of LG and presents simulation results on the viability of the starting strategy using different values of constant-magnitude motoring force. © 2008 IEEE.

Item Type: Conference or Workshop Item (Paper)
Uncontrolled Keywords: Automobile engines; Automobile parts and equipment; Brushless DC motors; Combustion; Cylinders (shapes); Electric generators; Electric machinery; Engine pistons; Engines; Magnets; Motion control; Motors; Permanent magnets; Propulsion; Resonance; Smoke; Thermochemistry; Free-Piston Linear Engine; Linear Electric Generator; Linear Generator Starting; Permanent-Magnet Brushless Motor; Rectangular Commutation; Engine cylinders
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
Departments / MOR / COE: Departments > Electrical & Electronic Engineering
Depositing User: Mr. Saiful Azrin bin Mohd Zulkifli
Date Deposited: 02 Mar 2010 01:19
Last Modified: 19 Jan 2017 08:26

Actions (login required)

View Item
View Item