Modelling and Control of a Power Flow Controller for DC Microgrids

Abstract

This paper presents a state feedback control method for a power flow controller for meshed DC microgrids. A modular generic dynamic model of the system is proposed. This model is augmented with integrators and linearised, and a state feedback control law is proposed to define the duty cycles for the PWM switching of the IGBTs. The power in each line and the voltage of a reservoir capacitor in the converter are directly controlled. The validity of the proposed model and control law are assessed on an experimental setup.

Robust nonlinear control of a power flow controller for meshed DC grids

“…This article continues a series of studies on the regulation of an m-terminal low voltage DC PFC drawn in Fig. 2 ( Simon et al, 2021b;Lin-Shi et al, 2021;Simon et al, 2021a). As explained in (Simon et al, 2021b), the system formed by the PFC and the microgrid can be modelled using a bilinear state-space model with uncertain parameters and a second-order polynomial output.…”

“…1 for the nomenclature. The dynamic model of the system can be found using the electrical laws for the current and voltage in inductors and capacitors, respectively, while assuming ideal components and switches (see (Simon et al, 2021b)). The signals are averaged over a switching period and the input vector…”

“…The meshed structure in microgrids improves its resiliency, flexibility and is the natural structure when loads and renewable generators are randomly distributed, see (Mackay et al, 2015), (Simon et al, 2021b) and the recent surveys (Fotopoulou et al, 2021;Mackay et al, 2017;Prakash et al, 2016).…”

“…2 ( Simon et al, 2021b;Lin-Shi et al, 2021;Simon et al, 2021a). As explained in (Simon et al, 2021b), the system formed by the PFC and the microgrid can be modelled using a bilinear state-space model with uncertain parameters and a second-order polynomial output. While many papers dealing with stabilisation problems for bilinear systems can be found in the literature (see for instance, (Gutman, 1981;Longchamp, 1980;Tarbouriech et al, 2009)), very few addressed the more general problem of output regulation, e.g., (Grasselli et al, 1979), and more recently (Cisneros et al, 2015;Tang et al, 2006).…”

Robust Regulation of a Power Flow Controller via Nonlinear Integral Action

“…The lower voltage rating leads to a completely different converter topology, and therefore to different control schemes. Among them, recall a multi-terminal PFC with a compensation node [6] improved by removing the compensation node [7], a PFC made of two separate Split-PI converters [8], and a three-terminal PFC [2], [9]. The main shortcomings of [6]- [8] are the absence of dynamic model and their control strategies, which fail to give any proof of stability or robustness.…”