Predictive Control Applied to a Cascaded H-Bridge Multilevel Converter Mohammad Ali Hosseinzadeh 1 , Maryam Sarbanzadeh 1 , Elham Sarbanzadeh 2 , Marco Rivera 1 and Patrick Wheeler 3 1 Faculty of Engineering, Universidad de Talca, Curico, Chile m.a hosseinzadeh@yahoo.com; maryam sarbanzadeh@yahoo.com; marcoriv@utalca.cl 2 Faculty of Engineering, University of Tabriz, Tabriz, Iran el sarebanzade@yahoo.com 3 Faculty of Engineering, The University of Nottingham, UK Pat.Wheeler@nottingham.ac.uk Abstract—Power converters are the main part of power electronic applications. A predictive strategy is a new control strategy to control cascaded H-Bridge (CHB) converter due to the control of multivariables, simultaneously. This report presents an overview on recent advanced predictive control techniques applied to a cascaded H-bridge (CHB) multilevel converter. The selected papers are chosen from the IEEE-explore database which have been published in the last couple of years. Index Terms—predictive control, cascaded h-bridge converter, mathematical model. I. I NTRODUCTION The conventional multilevel converters-inverters (MLCs/MLIs) configurations with industrial applications include cascaded H-bridge (CHB), a flying capacitor (FC) and natural diode clamped (NPC) multilevel converters [1]. The CHB converter is formed by H-bridge cells series connection and each cell is connected by dc isolated supplies. The CHB converter based on DC isolated supplies values is separated into two groups of symmetrical and asymmetrical structures. The magnitudes of the whole input of dc supplies are equal to the structure however in an asymmetrical one they are dissimilar. This report focuses on a three-phase cascaded H-bridge converter in the symmetrical mode, to apply the voltage for an R-L load [2]. Generally, there are three strategies in order to control and modulate a CHB converter: linear control, pulse width modulation (PWM) (carrier based) [3] and space vector modulation (SVM) [4], [5]. Other control strategies for low switching frequency have been suggested in [6]–[8]. New control methods have been introduced for power converters in the last decades. The presented method is the Model Predictive Control (MPC) which is used in the control of power converters due to ease of non-linear access, fast dynamic response and system constraints [9]–[11]. The MPC considers a system model to estimate its next behavior at a time horizon. In this case, to obtain the optimisation of the system’s behavior a cost function is defined. On the other hand, model predictive control solves the optimisation issue through a string of future actions which are achieved by minimizing the cost function. All calculations are done sequentially in each instance period and the first component of the string is implemented. In this report, a review on recent predictive control schemes for a CHB converter is presented. First, a mathematical model of the CHB converter is illustrated in detail. Next, the principle of predictive control applied to it is discussed. Finally, recent research papers that have been presented on the IEEE-explore database for CHB converters are reviewed, which have been published in the last couple of years. It is expected that the papers will contribute to all researchers that are starting to work in multilevel application areas. II. CHB CONVERTER MATHEMATICAL MODEL Fig. 1 displays the power topology of a three-phase CHB converter. This configuration includes two CHBs in each phase [12]. Each CHB creates 3 voltage levels of ± V dc and 0. Therefore, for each phase, the number of voltage levels is as follows: N L =2n +1 (1) Each cell in each phase is controlled by two independent switching functions and the a-phase cell voltage V ai is cal- culated as: V ai = V dc (S 1a,i − S 2a,i ) (2) As a result, the output voltage of the converter in to the neutral point N includes the total of output voltages of each cell. The V aN is obtained by: V aN = n  i=0 V ai (3) from the equations of (2) and (3), V aN can be expressed as: V aN = V dc n  i=0 (S 1a,i − S 2a,i ) (4) The number of switching states K S for an n cell of the CHB converter in each phase is obtained: K S =2 6n (5)