Energy Performance and Stability of Stirling Micro-Cogeneration System

The simultaneous production of heat and power at a small-scale is already a well known technique. Cogeneration is one of the main ways to bring about decentralised, embedded, localised and/or autonomous power production. However, it is still a challenge to design cogenerators to be below 10 kW as required for the smallest applications such as providing heat and power to a single house. This paper specifically introduces a Stirling cogeneration system for which nominal power is 1 kW. The system connects a new "double-effect" Stirling engine with a linear induction generator. The connection is done via the engine\´s piston that serves also as the secondary (mover) of the generator. First of all, the system is described, then, a state-space model of the co-generator under steady-state oscillatory conditions is presented in order to synthesize a controller that ensures robust stability and desired performances through the resistant effort created by the generator on the piston.