Modeling and dynamic analysis of accessory drive systems with integrated starter generator for micro-hybrid vehicles

Abstract

Belt-driven integrated starter generator system is a hybrid transmission that resembles the conventional serpentine belt-driven system. The system contains an integrated starter generator that performs a “start-stop” function on the engine. A two-pulley tensioner mechanism is attached to the integrated starter generator to maintain belt tension. The objectives of this paper are to develop modeling and calculation methods for estimating the performances of the belt-driven integrated starter generator system and to investigate the influence of damping of the two-pulley tensioner on vibration and shock. A systematic modeling and analysis method is proposed. The modeling method for the two-pulley tensioner is distinguished from any existing studies, which are generic for modeling the tensioner in belt-driven integrated starter generator systems with different layouts. A typical belt-driven integrated starter generator system is presented and a model is established to predict the dynamic response of rotational vibrations of pulleys, tensioner motions, and tension fluctuations. A parametric analysis is conducted to evaluate the two-pulley tensioner parameters with respect to their impact on the performances of the belt-driven integrated starter generator system.

Stick–slip oscillations of an engine front-end accessory drive system with a mechanical tensioner

“…13–16 However, there is only a few research works on influences of tensioner dry-friction on the dynamics of the EFEADS. 13–18 In the dynamics modeling and analysis of an EFEADS, the tensioner is usually simplified as a linear rotational spring and an equivalent linear viscous damper without considering the real actions of the tensioner dry-friction. 1,2,6–9,19,20 These simplifications are inconsistent with the actual situation, and thus, many nonlinear dynamic characteristics of the system cannot be accurately predicted.…”

Steady-state and start-up transient responses of a belt-driven starter generator system for micro-hybrid electric vehicles

“…In HEVs, an idle stop–start system is the main technique applied to realize the purpose of energy saving and emission reduction. For micro-HEVs, the belt-driven starter generator (BSG) system is a typical idle stop–start system and is used to substitute the traditional engine front-end accessory drive system (EFEADS) (Canova et al, 2009; Chen et al, 2020; Feng et al, 2019; Hu et al, 2020; John et al, 2007; Olatunde, 2008). Different from the traditional EFEADS, the BSG system uses a reversible motor with the function of starting motor and generating electricity to replace the traditional generator.…”

“…For the traditional EFEADS, a tensioner with only one pulley is placed on the slack belt span to ensure enough belt tension (Shangguan and Zeng, 2013; Zhu et al, 2018a, 2018b). However, when BSG system’s working mode switches between the starting mode and normally working mode, the tight and slight belt spans on two sides of the reversible motor will exchange (Feng et al, 2019). The belt tension should always maintain a large value to ensure no slippage if the one-pulley tensioner is used in a BSG system and the belt life will be greatly reduced as a result.…”

“…Canova et al (2009) examined the control of the start and stop dynamics of a HEV with a belted starter/alternator. Feng et al (2019) first discussed the influence of the tensioner with two arms and two pulleys on the steady-state and transient response of a belt-driven integrated starter generator system. The governing rotational vibration model of an accessory drive system with integrated starter generator and a tensioner with two pulleys was established by a so-called analytic geometry method.…”

“…Different from the traditional EFEADS, the BSG system uses a reversible motor with the function of starting motor and generating electricity to replace the traditional generator. Another difference between the traditional EFEADS and the BSG system is the tensioner mechanism (Feng et al, 2019; Olatunde, 2008). For the traditional EFEADS, a tensioner with only one pulley is placed on the slack belt span to ensure enough belt tension (Shangguan and Zeng, 2013; Zhu et al, 2018a, 2018b).…”