Hybrid predictive control of a DC–DC boost converter in both continuous and discontinuous current modes of operation

Abstract

Developing efficient and appropriate modeling and control techniques for DC-DC converters is of major importance in power electronics area and has attracted much attention from automatic control theory. Since DC-DC converters have a complex hybrid nature, recently several techniques based on hybrid modeling and control have been introduced. These techniques have shown better results as compared with conventional averaging-based schemes with limited modeling and control abilities. But the current works in this field have not considered all possible dynamics of the converters in both continuous and discontinuous current modes (CCM, DCM) of operations. These dynamics are results of controlled and uncontrolled switching phenomena in DC-DC converters. This paper proposes a new switching scheme for modeling and controlling a DC-DC boost converter. The converter is represented as a hybrid automaton by considering the all three possible modes. The hybrid automaton is translated into the mixed logical dynamical (MLD) mathematical framework. The switching among these modes is generated by hybrid predictive control method which is calculated by Mixed Integer Quadratic Programming (MIQP). Using the exact model of the converter, the proposed switching algorithm can globally control the converter in all operation regimes, including CCM and DCM operations, considering all constraints in the physical plant, such as maximum inductor current and capacitor voltage limits. The switching algorithm is applied to a real converter circuit, modeled with various parasitic components. Simulation results are provided to show the advantages of the proposed control scheme. 271Several approaches have been reported in literature for modeling and control of DC-DC converters . In [24], the principles of operation of these methods are reviewed, and the shortcomings of such methods are mentioned. The main drawback of all the existing methods is that their design is based on one operating mode of operation, i.e. either CCM or DCM. Therefore, the performance and stability of the closed-loop system are guaranteed only for one operation mode.There are applications like battery powered systems [25] in which operating the converter in CCM under full load conditions and in DCM under light load conditions to improve the overall efficiency is desirable. In such cases, the operation of the converter may move from CCM to DCM or vice versa during load and line disturbances.Recently, in [26,27], several hybrid control techniques from different research groups are introduced for DC-DC buck and boost converters. However, all of these works deal with only the CCM of operation. Hybrid modeling and control of a buck converter in the MLD framework, considering all possible dynamics in CCM and DCM operation was already introduced in [24]. In this work, the same idea of modeling and control in all operation modes is extended to a boost converter. Control of a DC-DC boost converter is more difficult than buck converter. This difficulty is due to non-minimum phase dynami...

On the complexity and dynamical properties of mixed logical dynamical systems via an automaton‐based realization of discrete‐time hybrid automaton

“…Furthermore, it provides an environment for the users to obtain low complexity MLD models with their own knowledge, heuristics, modeling art, and ideas. (vi) In the application side, this paper improves the previous studies on the MLD modeling and predictive control of DC‐DC converters in both continuous and discontinuous conduction modes from the complexity point of view . As another benchmark, a tank system is considered as a basic component of any process control system.…”

“…Equations (37) and (38) mean that, at each instant k, either only one of the invariant conditions or one of the guard conditions with reset dynamic in the DHA is satisfied. The terms in (37) and (38) are simplified to…”

“…23 Besides these theoretical aspects, the MLD framework in conjunction with the MPC has been used successfully to address many engineering problems such as traffic control systems, 24,25 optical grids, 26 networked control systems, 27 co-generation power plants, 28 microgrid systems, 29 traction control systems, 30 production-inventory systems, 31 and power electronics control systems. [32][33][34][35][36][37][38] In these applications, the MPC problem in [24][25][26][27][28][29][30][31][35][36][37][38] has been implemented online or implicit in which the control problem is solved repeatedly in each step time during the control operation. On the other hand, the MPC in the works of Geyer et al, 32 Mariéthoz et al, 33 Beccuti et al 34 has been executed offline or explicit in which the control problem is transformed into a multiparametric mixed-integer optimization problem.…”

“…(vi) In the application side, this paper improves the previous studies on the MLD modeling and predictive control of DC-DC converters in both continuous and discontinuous conduction modes from the complexity point of view. [35][36][37][38] As another benchmark, a tank system is considered as a basic component of any process control system. Similar benchmark systems consider the overall system as a switched system without any need to the automaton-based dynamic.…”

PI kontrolcü tabanlı yeni bir kontrol yapısının yükseltici DA-DA çevirici için tasarımı

“…İdeal olarak, çevirici giriş ve çıkış gerilimi arasındaki ilişki sistem parametrelerinden bağımsız anahtarlama oranına bağlı cebirsel olarak elde edilebilir. Ancak pratikte, ideal olmayan çevirici elemanları (pasif elemanlar ve anahtarlama elemanları) ve çeviricinin kesintili akım modunda çalışması durumu, çeviricinin ilgili çalışma noktası için belli bir anahtarlama oranının belirlenmesini olanaksız kılar [7]. Bu sebeple çeviriciye ait anahtarlama oranının elde edilmesi için, referans ve gerçek çıkış gerilimlerine dayalı bir geri beslemeli kontrol yapısının kullanılması zorunludur [8].…”