Adaptive Direct-Tuning Control for Variable-Speed Diesel-Electric Generating Units

This paper deals with an adaptive control method to be used in the dc-link voltage controller of diesel-electric power supply units being arranged with both permanent-magnet generator and three-phase boost rectifier. The proposed control method is based on the suitable manipulation of the overall system transfer function to achieve an adaptive “closed-form” expression for the parameters of the dc-link voltage controller. Such an approach allows overcoming the inherent nonlinear behavior of the system, so that the overall system dynamic performance is not affected by the system load conditions. Moreover, a current feedforward technique based on the estimation of the load current will be introduced to improve the control stiffness to load unbalances.