Abstract:
This paper is concerned with the increase of the damping behavior of an engine test bed by suitable extending the control strategy of a standard engine test bed with resp...Show MoreMetadata
Abstract:
This paper is concerned with the increase of the damping behavior of an engine test bed by suitable extending the control strategy of a standard engine test bed with respect to the test of high charged, small displacement combustion engines used in modern hybrid powertrain concepts. Especially in high performance engines (e.g. such as for race cars) the outbid boosting with electrical driven turbo chargers of the combustion engine leads to distinct excitation of the 0.5th order in case of a four cylinder engine. This stimulation coming from combustion engine could be root cause for high oscillations up to damage to the mechanical setup under full load conditions during engine testing. Since these oscillations are in frequency ranges where transport delay time for the dynamometer load system of the test bed becomes significant, a controller strategy based on a First-In-First-Out memory (FIFO) approach for delay compensation is chosen. The efficiency of the control strategy is shown by results from a real test bed experiment. To archive maximum damping effect, test bed load units (dynamometer) with high dynamic are used. Up to 70.000rpm/s acceleration of the dynamometer is needed - depending on the dynamic of the combustion engine - to achieve similar dynamic of the combustion engine seen in torque oscillation level. This goal can only be achieved by the use of synchronous permanent magnet dynamometers, which are characterized by very high torque to inertia ratio compared to asynchronous dynamometers.
Date of Conference: 27-30 August 2017
Date Added to IEEE Xplore: 09 October 2017
ISBN Information: