This paper presents a robust control strategy combining Space Vector Modulated Model Predictive Control (SVM2PC) with an Extended Kalman Filter (EKF) for online parameter estimation in grid-connected inverters. The proposed method enhances controller adaptability by rendering it independent of precise system parameter knowledge. The EKF continuously estimates key system parameters, enabling the predictive controller to perform accurately despite inductance variations. Simulation results demonstrate that, compared to conventional SVM2PC, the proposed EKF-enhanced approach achieves superior current tracking, reduced total harmonic distortion (THD), and preserved transient performance and stability, highlighting its effectiveness in improving control robustness under parameter uncertainties.

This paper presents a Continuous Control Set Model Predictive Control (CCS-MPC) enhanced with Nestorov Accelerated Gradient (NAG) for real-time closed-loop control of Cascaded H-Bridge (CHB) converters under normal operation and with faults on the power cells. The proposed method addresses limitations of conventional Finite Control Set MPC (FCS-MPC), including variable switching frequency and the computational burden for the control of multilevel converters. The main contributions of the proposed CCS-MPC with NAG are: (i) derivation of a dynamic model that enables simultaneous control of line currents and common-mode voltages under normal and fault conditions; (ii) formulation of the CCS-MPC problem as a convex, box-constrained optimization, enabling the use of an efficient projection-based solution within each NAG iteration to enforce feasibility; (iii) offline computation of matrices to minimize online computational burden; and (iv) a closed-loop reference voltage control to ensure fault-tolerant operation. The effectiveness of the proposed CCS-MPC with NAG is validated through real-time Hardware-in-the-Loop (HIL) simulations, that confirm the fast dynamic response and robust performance of the proposed algorithm under fault conditions and demonstrate its suitability for high-performance and reliable operation for industrial drives and grid-connected applications.

This paper proposes an optimal Finite Control Set Model Predictive Control for a three-phase Neutral Point Clamped inverter, considering its switching constraints. Initially, an optimization problem is solved to obtain the inverter line-to-line voltage vector that minimizes the current tracking error. Here, the constraints of the optimization problem are the lines that delimitate a convex hull around the last implemented vector, where the candidate vector presents at least one switching state which satisfies the switching constraint of the NPC inverter. The NPC’s redundant phase-voltage vectors are generated according to the switching constraint to avoid the potentially destructive switching transitions, and a cost function is then evaluated to balance the DC bus neutral point voltage, as the second control stage. As a result, the proposed Optimal FCS-MPC avoids the design of weighting factors and has the advantages of optimal performance, fast transient response, and superior steady-state performance, compared to similar algorithms. Finally, simulation results are presented to compare the proposed Optimal FCS-MPC algorithm with other FCS-MPC strategies presented in the literature, and the effectiveness of the proposed algorithm is demonstrated.

This study presents a methodology for determining the efficiency of electric motors and the thermal behavior of inverters, with a focus on the associated losses. An integrated simulation approach was developed, incorporating JMAG motor models, PLECs software for loss calculation, and Simulink for comprehensive system simulation. The methodology was validated through a vehicle’s driving and start-up cycles, producing efficiency maps across various operating conditions, including different switching frequencies and bus voltage levels. The results highlight the broad applicability of this simulation methodology to various types of machines and semiconductor technologies. This approach is particularly effective for accelerating the development of traction inverters, providing valuable insights for optimizing system performance.

This article proposes a space vector modulated model predictive control (SVM$^{2}$PC) for voltage source converters. It overcomes limitations of standard finite control set model predictive controller, ensuring fast dynamic response, fixed switching frequency, and low computational burden. It combines control and modulation in a convex optimization problem with affine inequality constraints to minimize the tracking errors of the output variables. First, the sector of the space vector diagram where the unconstrained solution lies is identified. Then, using the Karush–Kuhn–Tucker conditions, feasible duty cycles are computed for both linear and overmodulation regions. The proposed SVM$^{2}$PC is extended to multilevel converters. Hardware in the loop results are presented for three different case studies: 1) Grid-forming inverter withLCfilter; 2) two-level grid-following inverter with LCL filter; and 3) grid-following neutral point clamped inverter with LCL filter. Experimental results demonstrate that the proposed SVM$^{2}$PC provides good performance, fast response, and low computational burden when compared with previously reported alternatives.

This paper proposes a Geometrical Modulated Model Predictive Control (GM 2 PC), for grid-connected converters, ensuring voltage synthesis and current limiting with fast dynamic response, low computational burden and fixed switching frequency, also addressing the overmodulation issue. A discrete-time model for a converter with LC output filter and external disturbances is derived. Then, a convex optimization problem with two quadratic inequality constraints is formulated for minimizing the output tracking error. To solve this problem, each constraint is considered to be a circular area over the space vector diagram for voltage synthesis and current limitation. Using the Karush–Kuhn–Tucker conditions, an unconstrained solution is obtained in order to identify in which mode the proposed method should operate. Finally, a Hardware-in-the-Loop validation for a three-phase two-level inverter is presented. The results demonstrate that the proposed method is capable of providing good performances with a fast and efficient control algorithm.

This paper investigates the impact of the dead-time compensation on fixed frequency space vector modulated model predictive control for grid-tied inverters. Since grid-tied inverters with LCL filters may have inverter-side currents with large high-frequency current ripple, multiple zero crossings should be properly considered for dead-time compensation. Therefore, this paper proposes a method to predict the current at the switching instants within the sampling period. It is demonstrated that there is a significant improvement in terms of low-frequency harmonics and tracking error of the grid-side currents with the proposed method. In addition, the constraints imposed by the dead-time compensation are included in the optimization problem of the Space Vector Modulated Model Predictive Control algorithm. Finally, Hardware-in-the-loop results are presented to demonstrate the good performance of the proposed dead-time compensation technique.

This paper describes a simple optimum carrier-based geometrical modulation for both NPC and T-Type inverters. The current that flows through the midpoint of the DC bus can be controlled in order to balance the capacitor voltages for a wide range of modulation indexes and power factors. This was accomplished by adding to the reference phase voltages a common-mode voltage vo,obtained by solving an optimization problem. In order to validate the good performance of the proposed modulation strategy, experimental results with Typhoon HIL are presented for NPC and T-Type inverters for different modulation indexes and power factors.

This paper proposes a Modulated Model Predictive Control (M2PC) algorithm for the three-phase Packed-U-Cells, PUC5, converter, that aims to minimize the output current error and balance the voltages of the DC bus capacitors. In order to do so, two cost functions are defined. The first one selects the sector in the SV diagram that minimizes the output current error, not taking into account the redundancies of the converter voltage vectors. After this, a second cost function for balancing the DC bus capacitor voltages is evaluated, considering only the voltage vectors of the chosen sector, including their redundancies. In this way, the proposed M2PC results in output voltages with fixed switching frequency, having a positive impact on the design of the output filter. Simulation results are shown, comparing the proposed M2PC and the standard variable frequency MPC strategies in terms of output current and voltage, internal capacitor voltage balancing and harmonic content.

Generally, space vector modulation strategies employ the Three Nearest Vectors (NTV) to the reference voltage vector in order to achieve low distortion on the output voltages. When it comes to multilevel converters, the modulation technique must deal with a large number of redundancies and sometimes it must also perform the balance of the capacitor voltages, depending on the converter topology. This paper proposes a space vector modulation strategy applied to Packed-U-Cell Converters (PUC). It is proposed a cost function to be minimized comprising two objectives: (i) adjacent switching vectors distance minimization (ii) desired currents in order to keep the capacitors charged. The proposed cost function minimization results in a optimized switching sequence and balanced capacitor voltages. Simulation results demonstrate the good performance of the proposed modulation strategy.

The IPC is a technique used for reducing structural loads in wind turbines like wind shear, tower shadow and wind turbulence by means of a control loop whose outputs are the resulting Tilt and Yaw Moments and the manipulated variables are the blade pitch angles. As the wind turbine model for structural analysis is highly nonlinear, with parametric uncertainties and variations, this paper proposes an IPC-based decentralized Robust Model Reference Adaptive Controller, RMRAC, aiming to address these challenges. The proposed IPC-RMRAC makes use of strain gauges to measure the blade root loads and controls each blade pitch angle independently. Simulations with 1.5 MW wind turbine using NREL FAST software were performed, showing the feasibility of the proposed algorithm. The results are discussed and compared with Collective Pitch Controller.

This paper proposes a space vector vector pulse width modulation (SVPWM) stratey for Modular Multilevel Converters (MMCs). The proposed modulation generates multilevel output line-to-line voltages with 4N+1 levels. Furthermore, the virtual vectors are developed for the MMC and it allowed to establish the converter voltage limits and implement a proper inner currents control. Moreover, the voltages across the submodule dc capacitors can be well balanced with closed-loop controllers and a sorting algorithm. Finally, simulation results are presented to support the theoretical analysis demonstrating the good performance of the proposed modulation technique.

This paper extends the carrier-based discontinuous modulation for inverters with three parallel magnetically coupled legs. In order to simplify the analysis and implementation, the modulation is developed in the converter phase voltage framework. The core of the modulation is a state machine, that allows the distribution of the PWM pulses among the parallel legs, without increasing the number of commutations, when compared to conventional PD modulation methods. A detailed discrete-time model is given, aiming to design the controller for the circulating currents. Finally, simulation and experimental results are given, to validate the theoretical analysis and to demonstrate the feasibility of the proposed modulation technique.

This paper presents an alternative approach for sensorless vector control of permanent magnet (PM) brushless motors with nonsinusoidal back electromotive force (EMF). The approach uses a new dynamic model for surface-mounted PM motors, which is expressed in a synchronous reference frame with orientation on back-EMF vectors. Thus, it is possible to demonstrate under this orientation frame that the electromagnetic torque is proportional to the quadrature stator current similar to the classical vector control. As a result, the torque ripple can be easily minimized even with highly nonsinusoidal back-EMF. In addition, a nonsinusoidal vector control scheme is proposed using an observer to estimate the back-EMFs which are required for the rotor speed estimation as well as for the frame transformations. In order to allow energy efficiency improvement, a hybrid orientation scheme using variable cutoff frequency filters is adopted to select desired back-EMF harmonic components that compose the synchronous reference frame. Consequently, harmonic currents can be reduced at high speed to decrease iron losses. The good performance of the proposed approach is verified by simulation and experimental results.

This paper proposes an algorithm for the on-line definition of switching sequences for Space Vector Modulation (SVM) of the low voltage power cells of asymmetrical multilevel cascaded converters. Initially, an algorithm to define on-line the redundancies of the three nearest low voltage vectors is described in details. The first vector of the new sequence is chosen so as to minimize the switching losses between two consecutive reference samples. Then, the remaining vectors are organized within the switching period in a way such as to have the least number of commutations. As a result, minimum switching losses is achieved, even in the transition between sectors. Furthermore, the algorithm can also define sequences for any fault condition, avoiding the use of different look-up tables. Finally, experimental results are shown to validate the proposed algorithm.

This paper proposes a new and simple hybrid modulation strategy for asymmetrical cascaded multilevel converters (ACMCs) operating under fault conditions in the low-voltage-high-frequency (LVHF) cells. The theoretical analysis is explained through an example, an ACMC with one 1pu and one 2pu cell per phase. The modulation strategy integrates the benefits of both geometrical and space vector approaches. The last one is used to define the voltages for the high-voltage-low-frequency (HVLF) cells, such as to avoid the overmodulation of the LVHF cells. The carrier-based geometrical approach is employed for the LVHF cells to simplify the implementation of the algorithm, since the PWM signals are obtained via the comparison of modulating voltages to triangular carriers, with no need to define switching sequences for the low voltage vectors. As a result, the proposed algorithm is considerably simplified when compared to the space vector. Simulation and experimental results are given to validate the proposed method and to demonstrate its good performance.

This paper presents in details a dynamic model suitable for the design of speed controllers of ethanol fueled internal combustion engine (ICE), applied for variable speed gensets. First, two dynamic models are developed for the ICE: the Time Based model and the Event Based model which is referred to the crankshaft angle. The speed controller design is held through the Event Based model linearization and discretization. This model has advantages for implementation of a speed controller especially regarding the transport delay which becomes fixed. For the ICE speed control it is proposed the use of a proportional integral controller because of its simplicity and ease implementation. The PI design is developed in frequency domain and its stability is ensured by the phase and gain margin. In addition, it is also proposed an integral anti-windup action and a feed forward action aiming at faster transient responses. Experimental results on a 50 kW generator set are provided to validade the model and to demonstrate the system good performance.

This work presents a comparison of three state feedback controllers suitable for application to DC-DC boost converters with large load range. These converters are an important stage in several renewable source systems. The first controller is a conventional LQR designed for a single operating point. The second controller uses the switching between LQR controllers designed for a set of load conditions (local controllers). The third controller is a fuzzy logic based controller which is based on the convex combination of the local controllers. The second and the third controllers use the load current as a decision variable. The implementation of all controllers is carried out in a TMS320F2812 fixed-point DSP, considering the transport delay and the limitation of data format from this digital control platform. Simulation and experimental results obtained for the three control strategies submitted to load disturbances allow to observe the quality of the transient and steady state responses, leading to the conclusion of the superiority of the fuzzy logic based controller in terms of a better tradeoff between performance and spent of control energy.

This paper aims on the design and experimental validation of a discrete-time H∞control for single phase PWM inverters with linear and nonlinear loads, providing results complying with IEC 62040-3 Standard for uninterruptible power supplies. This compliance ensures sinusoidal voltages of high quality for critical loads. The H∞control used here is designed by means of linear matrix inequality conditions including constraints on the norm of the control signal, in order to ensure high performance with a feasible action of control, avoiding saturation and high spent of energy from the actuator. Additionally, the controller is implemented in a digital signal processor under constraints as delay in the application of the control signal and limitations on precision and dynamic range of data representation. The control action is a linear combination of the plant states and the states of a controller based on the internal model principle, allowing to track sinusoidal reference signals in the presence of loads with harmonics. The main contribution of the paper is the experimental implementation of this control technique taking into account all the above constraints and producing results complying with IEC 62040-3 Standard.