Robust feedback‐linearisation control of a boost converter feeding a grid‐tied inverter for PV applications

Abstract

In this study, the feedback-linearisation (FBL) technique is employed to design a dc-dc boost voltage regulator feeding a grid-tied inverter for photovoltaic (PV) systems. The key feature of the proposed approach is that only a voltage control loop is used to generate the driving signal for the converter and no current control loop is required. Thereby, unlike the cascaded structure, the bandwidth of the voltage control loop can be specified only by the switching frequency as there is no need for an intermediate inner-loop. The major concern of this control scheme is its limited ability to eliminate completely the steady-state error under model uncertainty and unknown disturbance such as the PV current, which is considered as an unmatched disturbance. For this purpose, the unknown perturbation is estimated by a disturbance observer and compensated in the control law to drive the steady-state error to zero. With a fast disturbance estimation, the composite controller is able to retain the nominal transient performance specified with the FBL. The effectiveness of the proposed approach was verified by both simulation and experimental results, and a remarkable agreement was obtained while exhibiting excellent performances.

Observer‐based control of a photovoltaic DC–DC buck converter: HDS approach

“…is the derivative with respect to the time of the desired current I d (22). The current of output current I L may also be required in some applications if the charging current of the battery is greater than the maximum charge current for standalone PV application, or during some battery-charging processes [33].…”

“…However, the PV current iss not observed. In a disturbance observer is used to observe the inductor current and output voltage of a boost converter; this latter model is considered linear.…”

Optimised damping control of islanded DC power systems using state feedback

“…Referring to the full dimension state feedback theory, a proportional-integral (PI) controller is added to the grid-connected converter, but the control structure is more complex for parameter design [19]. Based on state feedback, a linearisation control method is proposed to reduce the effect of CPL on system stability [20][21][22]. However, in actual practice, it is difficult to achieve a linearising function due to parameter mismatch.…”

Virtual charge‐based synchronisation and feedback linearisation‐based current control of a three‐phase grid‐connected inverter without grid voltage sensors

“…This paper proposes a non‐linear control strategy based on feedback linearisation (FL) with a virtual charge estimation algorithm to obtain the grid voltage from the measured current. FL completely decouples and linearises the non‐linear plant over the whole operating range [7–9]. FL‐based control techniques have been reported only in the synchronous dq reference frame implemented via proportional–integral controllers [7, 8].…”