Due to the increasing presence of renewable inertia-less energy sources, power electronics interfaces are required to exploit their flexibility in order to support the overall grid quality of service. One way to achieve this, is that power converters are capable of actively track active and reactive power-setpoints, that are computed by suitable centralized or decentralized control schemes. In this paper, we propose a novel algorithm which enables the control of a boost converter to achieve arbitrary active-power reference tracking for photovoltaic plants, not operating in maximum power point tracking (MPPT) mode.