Abualkasim Bakeer

A Powerful Finite Control Set-Model Predictive Control Algorithm for Quasi Z-Source Inverter

Today, a predictive controller becomes one of the state of the art in power electronics control techniques. The performance of this powerful control approach will be pushed forward by simplifying the main control criterion and objective function, and decreasing the number of calculations per sampling time. Recently, predictive control has been incorporated in the Z-source inverter (ZSI) family. For example, in quasi ZSI, the inverter capacitor voltage, inductor current, and output load currents are controlled to their setting points through deciding the required state; active or shoot through. The proposed algorithm reduces the number of calculations, where it decides the shoot-through (ST) case without checking the other possible states. The ST case is roughly optimized every two sampling periods. Through the proposed strategy, about 50% improvement in the computational power has been achieved as compared with the previous algorithm. Also, the objective function for the proposed algorithm consists of one weighting factor for the capacitor voltage without involving the inductor current term in the main objective function. The proposed algorithm is investigated with the simulation results based on MATLAB/SIMULINK software. A prototype of qZSI is constructed in the laboratory to obtain the experimental results using the Digital Signal Processor F28335.

Control of switched-inductor quasi Z-Source Inverter (SL-qZSI) based on model predictive control technique (MPC)

Model Predictive Control (MPC) becomes more prevalent in power converters due to its faster response in tracking the reference values of the controlled variables. In this paper, the MPC is applied on the Switched-Inductor quasi Z-Source Inverter (SL-qZSI) topology. The MPC modeling for the capacitor voltage, inductor current, and output load current of the topology are designed to predict their values in the future. These prediction values are compared with the reference values to compose the cost function and then the switching state is selected to achieve the minimum cost function. The validation of the modeling is investigated by simulation under MATLAB platform. Then, it is also confirmed by experimental work using a laboratory prototype.

Development of MPC algorithm for quasi Z-source inverter (qZSI)

This paper presents an improvement algorithm of Model Predictive Control (MPC) for the quasi Z-Source Inverter (qZSI) with a standalone system. The improved algorithm decreases number of the desired sensors from five into three, where it just needs two current sensors for measuring the AC currents, and another voltage sensor for capacitor voltage detection. The inductor current will be estimated according to the previous optimized state and the capacitor voltage value during this state. Moreover, the developed algorithm decreases the number of the calculations for the inductor current prediction. Thus, the total cost of the control system decreases; furthermore, the practical implementation for the algorithm is improved where short running time. The developed algorithm will be investigated with the theoretical analysis in addition to the simulation validation based on MATLAB/SIMULINK as environmental software.

Grid connection quasi Z-Source Inverter based on model predictive control with less sensors count

this paper presents Model Predictive Control (MPC) to tie three-phase quasi Z-Source Inverter (qZSI) to the utility grid. Regularly, to control the capacitor voltage in qZSI based on MPC, the inductor current is the key factor. Here, the proposed algorithm has the features of decreasing the number of sensors where the inductor current sensor is removed to improve the cost and foot print of the control implementation. The value of the inductor current is defined according to an estimation methodology that uses the previous optimized switching state and the capacitor voltage during this state. In addition, the proposed algorithm has the features of decreasing the number of iteration to improve the response of the control. The proposed technique has been explained in details over theoretical analysis and confirmed with the simulation results utilizing MATLAB/SIMULINK software. Additionally, experimental validation has been presented using the digital signal processor F28335 with hardware setup.

A modified two switched-inductors quasi Z-Source Inverter

Up till now, a lot of work is done to improve the features of Z-Source Inverter (ZSI) as a single stage inverter through the modification in the construction of the basic topology. A modified two switched inductor quasi Z-source inverter (MTSL-qZSI) topology is proposed in this paper. The principle of the proposed topology depends on using the bootstrap capacitor instead of the center diode in one switched cells of the traditional continuous input current switched inductor quasi Z-Source Inverter (cSL-qZSI) topology. The proposed topology gives high boosting gain, improves voltage stress across the capacitors and the switched devices at the same total gain (G), and has higher conversion efficiency compared to the classic (cSL-qZSI) topology. A detailed theoretical analysis is introduced for the proposed topology. Also, a comparison between the proposed topology and the convention one (cSL-qZSI) is presented in this paper. Then, the theoretical analysis is verified by results from simulation and experimental prototype with a good matching.