Different torque damping by a constant speed SPM machine drive in domestic cogeneration system

The domestic combined heat and power (CHP) system is an effective residential distributed energy generation technology. Nano-CHP is an energy-efficient technology that simultaneously provides heat and electricity to households. An electrical machine (EM) connected to internal combustion engine (ICE) is principally used to produce the electricity. The conventional ICE during the combustion process produces an oscillating torque which affects the vibration and the noise of the system and also reduces the power train life time. The new opportunity for electric drive is to reduce the speed pulsation using the EM which is controlled as active torque damping by applying an inverse torque sequence to crankshaft. In this paper different torque damping techniques have been analyzed with the aim to find the better solution; the investigated techniques have been taken from researches in the field of hybrid electric vehicles. In order to better understand the torque engine oscillation phenomena an effective ICE model has been realized. It allows to find out by simulations the best available technique. The ICE model and simulation analysis predict the system performance, that has been validated by experimental test carried out on a dedicated laboratory test bench composed by a real ICE connected to EM.