In this study, a new proportional-integral-type hyper-plane sliding mode controller has been designed for output voltage control of the DC-DC buck/boost converter for its continuous and discontinuous conduction modes of operating conditions. The proposed controller is robust and stable against parameters uncertainties, load disturbance and variations of the converter input voltage. In addition, it is capable of cancelling the non-minimum phase nature effect of the converter so that the designed controller does not need to know the inductor reference current. Moreover, the coefficients of the controller have been designed so that the steady-state error of the converter asymptotically converges to zero. The controller is designed based on fixed-frequency equivalent control approach. Using MATLAB/SIMULINK toolbox and digital signal processor (TMS320F2810) from Texas Instruments, some simulation and practical results are presented to verify the capability and effectiveness of the proposed control approach.

In this study, a cascade two-loop non-linear controller is developed for single-phase shunt active power filters which is robust and stable in a wide range of output current and DC-link voltage changes. A variable structure proportional-integral controller is designed to regulate DC-link voltage in the outer loop. Also filter output current is controlled in the inner loop using adaptive backstepping approach. All of the model uncertain parameters are estimated using designed estimation rules. By introduction of suitable Lyapunov functions, proposed controller stability is investigated using Barbalat lemma. Grid reference current is calculated indirectly using a phase-locked loop circuit according to DC-link voltage error. Designed active power filter has been implemented using TMS320F28335 digital signal processor and practical response of the developed controller is studied in some tests. It is shown that the proposed controller is able to eliminate harmonic components of the local load current with a fast dynamic response. Also, compensation capability of the designed non-linear approach is compared with sliding mode controller in similar conditions.

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In this study, a hyper-plane multi-input-multi-output (MIMO) sliding-mode controller (SMC) is presented for control of the grid-connected Z-source inverter (ZSI). The presented controller can simultaneously control all of the system state variables including grid-side AC current and DC-link capacitors voltage. These state variables are directly regulated by amplitude modulation index and shoot-through interval. The non-minimum phase problem of the capacitors voltage is solved by indirect regulation of the DC-side inductor current. The proposed controller is developed using non-linear MIMO model of the converter; hence, it is possible to apply the proposed controller in a wide operating range. Controller coefficients are designed using Jacobian linearisation approach to ensure stability of the system. According to application of the Lyapunov approach, it is proved that the proposed controller is asymptotically stable against changes of the system state variables. Some simulations are presented to verify the effectiveness and stability of the developed controllers by MATLAB/Simulink toolbox. Also, a laboratory prototype is implemented using a digital signal processor TMS320F28335. Experimental results are given for the presented controller in the single-phase ZSI. It is seen that the experimental and simulation results are in good agreement.