Four-leg voltage source inverter is an evolution of the three-leg inverter, and was ought about by the need to handle the non-linear and unbalanced loads. In this work Matlab/ Simulink model is presented using space vector modulation technique. Simulation results for worst conditions of unbalanced linear and non-linear loads are obtained. Observation for the continuity of the fundamental inverter output voltages vector in stationary coordinate is detected for better performance. Matlab programs are executed in block functions to perform switching vector selection and space vector switching.
This paper proposes a new control circuit to control the switching of the main switches of the used Zero Current Zero Voltage Transition (ZCZVT) inverter to ensure Zero Current and Zero Voltage Switching (ZCZVS). The reverse recovery losses of the main diodes are minimized and the auxiliary switches of the commutation cell are turned on at Zero Current Switching (ZCS) and off at ZCZVS. The commutation losses are practically reduced to zero due to ZCS. Sinusoidal Pulse Width Modulation (SPWM) is used to perform the switching of the power semiconductor devices and to control the output voltage value. MATLAB software is used to simulate the inverter circuit. Simulation results are presented to demonstrate the feasibility of the proposed control circuit.
Use of multilevel inverters is becoming popular in the recent years for high power applications. The important feature of these inverters is of having low harmonics content in the output voltage. The switching angles in a multilevel inverter are computed so as to produce an ac output voltage with minimum harmonics. A new control circuit is designed to achieve these angles. This control circuit has the ability to control the RMS output voltage using sinusoidal pulse width modulation (SPWM). The results presented in this work prove the ability of the designed control circuit to gain the required ac output voltage with minimum distortion.
The Intelligent Control of Vibration Energy Harvesting system is presented in this paper. The harvesting systems use a me- chanical vibration to generate electrical energy in a suitable form for use. Proportional-Integrated-derivative controller and Fuzzy Logic controller have been suggested; their parameters are optimized using a new heuristic algorithm, the Camel Trav- eling Algorithm(CTA). The proposed circuit Simulink model was constructed in Matlab facilities, and the model was tested under various operating conditions. The results of the simulation using the CTA was compared with two other methods.
A Matlab/Simulink model for the Finite Control Set Model Predictive current Control FCS-MPC based on cost function optimization, with current limit constraints for four-leg VSI is presented in this paper, as a new control algorithm. The algorithm selects the switching states that produce minimum error between the reference currents and the predicted currents via optimization process, and apply the corresponding switching control signals to the inverter switches. The new algorithm also implements current constraints which excludes any switching state that produces currents above the desired references. Therefore, the system response is enhanced since there is no overshoots or deviations from references. Comparison is made between the Space Vector Pulse Width Modulation SVPWM and the FCS-MPC control strategies for the same load conditions. The results show the superiority of the new control strategy with observed reduction in inverter output voltage THD by 10% which makes the FCS-MPC strategy more preferable for loads that requires less harmonics distortion.
This paper suggests the use of the traditional parallel resonant dc link (PRDCL) circuit to give soft switching to the Four-leg Space Vector Pulse Width Modulation (SVPWM) inverter. The proposed circuit provides a short period of zero voltage across the inverter during the zero-vectors occurrence. The transition between the zero and active vectors accomplished with zero- voltage condition (ZVC), this reduces the switching losses. Moreover, the inverter output voltage Total Harmonic Distortion (THD) not affected by circuit operation, since the zero voltage periods occur simultaneously with zero-vector periods. To confirm the results, balanced and unbalanced loads are used. Matlab/Simulink model implemented for simulation.