In this Letter, a hybrid particle swarm optimisation and gravitational search algorithm (PSO-GSA) to tune the parameters of proportional-integral (PI) controller operating in cascade with sliding mode controller (SMC) is proposed for the design of Cuk converter for low-voltage electric vehicle application. The PI controller in the outer loop regulates the voltage and SMC in the inner loop regulates the current of converter operating in continuous conduction mode. The main objective of Cuk converter with PSO-GSA tuned PI & SMC controller is to track the reference voltage amidst disturbances, and to reduce the performance indices such as integral absolute error (IAE) and integral time absolute error. Initially, PI controller was tuned using Routh Hurwitz and root locus method. Then to improve its steady-state performance index, PSO-GSA technique is applied to tune the proportional and integral gains. To validate the effectiveness of the proposed scheme, the performance indices such as IAE, integral squared error was measured and compared. The results obtained reveal that IAE is reduced to minimal value and the solution converges at a faster rate with the proposed controller than the conventional control methods. Moreover, the stability analysis was carried out using the Lyapunov method of stability.
An efficient pulse width modulation scheme for Cascaded H-Bridge inverter (CHBI) is proposed in this paper. The proposed modulation scheme is a low switching frequency modulation scheme termed as modified Nearest Level Modulation (mNLM) scheme. Compared to the conventional nearest level modulation (NLM) scheme, the proposed modulation scheme reduces the total harmonic distortion (THD) at the ac output of the inverter. The mNLM follows an algorithm presented in the paper in order to arrive at a set of switching angles for MLI which offers reduced THD. Simulation is carried out using MATLAB/Simulink 2015b software and hardware is presented which validates the simulation results. Results show that there is a notable reduction in the THD content with the use of proposed modulation scheme. Because of the improved THD content, improvement in the other inverter parameters such as rms voltage, rms current and increased output power is also observed.
Highlights• This paper focuses on different control topologies of power converter • A Non-Linear system was investigated in steady state and transient region.• Proposed system was regulated the DC output voltage in load disturbances region.
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