Sliding-Mode Control of a Dc/Dc Postfilter for Ripple Reduction and Efficiency Improvement in POL Applications

Abstract

This paper proposes an active postfilter based on two Buck converters, connected in parallel, operating in complementary interleaving. In such a configuration the ripple in the load current could be virtually eliminated to improve the power quality in comparison with classical Point-Of-Load (POL) regulators based on a single Buck converter. The postfilter is designed to isolate the load from the main Buck regulator, leading to the proposed three-converter structure named BuckPS. The correct operation of the postfilter is ensured by means of a sliding-mode controller. Finally, the proposed solution significantly reduces the current harmonics injected into the load, and at the same time, it improves the overall electrical efficiency. Such characteristics are demonstrated by means of analytical results and illustrated using numerical results.

Sliding-Mode Control of a Charger/Discharger DC/DC Converter for DC-Bus Regulation in Renewable Power Systems

“…At the societal level, the renewable sources decrease the greenhouse gas emissions, improve the distribution system by increasing the population coverage, and provide service for both off-grid areas and stand-alone applications [11][12][13]. The technological level presents many challenges: on the one hand, it is required to improve the conversion device, namely, more efficient, economical and reliable the photovoltaic panels or fuel cells [14][15][16][17]; on the other hand, it is required to improve the strategies for maximizing the energy production [18][19][20], improve the power quality [21][22][23] and fulfill some non-functional requirements as reliability, scalability, size, cost, etc. [24][25][26].…”

“…Most control systems based on sliding-mode include in the sliding surface the error of one, or multiple, system states [22,48], e.g., capacitors voltage or inductors current. Moreover, other sliding-mode controllers adopt more complex sliding surfaces: for example, the work reported in [49] propose a sliding surface formed by the output voltage error, and both the time integral and derivative of that error, this to stabilize a Buck converter with constant power load.…”

Proportional Load Sharing and Stability of DC Microgrid with Distributed Architecture Using SM Controller

“…These controllers require a linearized model of the system, which makes it difficult for them to show good power sharing performance and stability in all operating conditions [33][34][35]. So, an SM controller is alternatively proposed in [36][37][38][39][40]43] which ensures stability in all operating conditions. Hence, in this paper, an SM controller technique is proposed for proportional load sharing and stability of DC microgrids.…”

“…In sliding mode, most of the controllers include error of one or multiple states of the system in the sliding surface (e.g., inductor current or capacitor voltage) [44,45]. Furthermore, some controllers include error and both of the time derivative and the integral of the error in the sliding surface to stabilize the system [38]. In this case, the sliding surface can be represented as a secondorder differential equation for which extensive mathematical analysis is required to guarantee system stability.…”

“…SMC for microgrid type systems is reported in [9,[36][37][38][39][40]. SM is a controller which is used for variable structure systems [36].…”