Active Torque Damping for an ICE-Based Domestic CHP System With an SPM Machine Drive

A domestic combined heat and power (CHP) system is an effective residential distributed energy generation technology. Nano-CHP is a growing technology that simultaneously provides heat and electricity to households. An electric machine (EM) connected to an internal combustion engine (ICE) is used to produce the electricity, whereas an ICE delivers heat. Any conventional ICE exhibits pulsating torque that causes vibration and noise in the system and reduces the powertrain lifetime. An additional task for the electric drive of smoothing the speed oscillations by controlling the EM as an active torque damping system, which applies an inverse torque sequence to the crankshaft, is here proposed. In this paper, different torque damping techniques have been explored with the aim of finding out the best solution; the investigated techniques have been taken from research in the field of hybrid electric vehicles. In order to model the torque engine oscillation phenomenon, an effective but simple ICE model has been developed. It allowed the comparison of the different techniques by simulations; some of them have been later validated by experimental tests carried out on a dedicated laboratory test bench composed of a real ICE connected to an EM.