In this paper, a model predictive control scheme for the T-type inverter with an output LC filter is presented. A simplified dynamics model is proposed to reduce the number of the measurement and control variables, resulting in a decrease in the cost and complexity of the system. Furthermore, the main contribution of the paper is the approach to evaluate the cost function. By employing the selection of sector information distribution in the reference inverter voltage and capacitor voltage balancing, the execution time of the proposed algorithm is significantly reduced by 36% compared with conventional model predictive control without too much impact on control performance. Simulation and experimental results are studied and compared with conventional finite control set model predictive control to validate the effectiveness of the proposed method.
This paper introduces a new three-phase two-level inverter based on the switched-capacitor voltage multiplier. By adding a voltage multiplier network at the DC side of the traditional three-phase inverter topology, the DC-link voltage of the introduced inverter is stepped up to triple of the input voltage. Compared to the existing solutions, the common-mode voltage of the introduced topology is kept constant. Moreover, the voltage stress across additional semiconductor components is the same as one-third of DC-link voltage. Operating principles, mathematical analysis, circuit analysis, and pulse-width modulation (PWM) method based on the Boolean logic function for introduced inverter are presented. A comparison of the introduced inverter with other inverter topologies is also reported. The simulation results are shown to verify the introduced three-phase triple voltage boost inverter. Besides that, a laboratory-built prototype is developed based on a DSP F280049C microcontroller and the corresponding experimental tests are provided to prove the introduced inverter.
This paper presents a detailed description of Finite Control Set Model Predictive Control (FCS-MPC) applied to three-level neutral point clamped inverter (3L-NPC). The controller uses a model of the converter, DC link and load to calculate predictions of the future values of the load currents and DC-link capacitor voltages for all possible voltage vectors. The cost function is defined to minimize the error between the reference currents and predicted load currents, balance the DC-link capacitor voltage and reduce the switching frequency. The optimal switching state that minimizes the cost function is selected and applied to the converter. Furthermore, the quality of the current and voltage are improved by using a two prediction steps procedure. Simulation results for the one and two prediction step are presented and compared with linear current controller and space-vector modulation (PI-SVM). The obtained results show the better performances of the proposed control method.
The space vector modulation (SVM) method using only rotating vectors is very effective to suppress the common-mode voltage (CMV) for matrix converters (MCs). However, the effect of the input filter on the input power factor (IPF) has not been fully investigated when using this method. This study investigated the effect of the input filter on the displacement angle and proposes an IPF compensation strategy for the zero CMV-SVM method in MCs. The proposed strategy analyzes the duty cycles of rotating vectors under the IPF-compensation condition. Through this analysis, the proposed strategy adjusts the zero vector by using a set of three counterclockwise-rotating vectors or three clockwise-rotating vectors to make all the duty cycles non-negative, ensuring that the zero CMV-SVM method can be applied to compensate the IPF for the MCs. This study also determines the condition to achieve unity IPF for the main power source and the maximum allowable IPF if the above condition is not met. Finally, experimental results are provided to validate the theoretical study.