This paper presents a new three-level reduced switch-count three-phase F-type rectifier and its control without current sensing. Unlike the existing three-level three-phase rectifier topologies, which use twelve switching devices, the proposed topology uses only nine switches. This, in turn, reduces costs and enhances reliability. Moreover, the voltage stress on the switching devices is more evenly distributed across the components, leading to the use of lower voltage-rated devices. The control of the proposed rectifier is achieved by a control strategy that eliminates the need for current sensing which reduces control implementation costs. The functionality of the proposed topology and its control method is verified using MATLAB/Simulink simulations under different operating conditions, including steady-state operation, step changes in resistive load, and variations in the reference DC-link voltage. The simulation results verify that the DC-link voltage is effectively controlled, and the total harmonic distortion (THD) of the grid currents remains within the limits defined by international standards.

This study presents a comprehensive analysis of Terminal Sliding Mode Control (TSMC) and Super Twisting Sliding Mode Control (SOSMC), in the context of full-bridge single-phase inverters. The controllers are designed to output current control of the single-phase inverter. Simulation studies are performed on MATLAB/Simulink platform to investigate the dynamic responses, steady-state error, ripple magnitude and total harmonic distortion (THD). The results indicate that TSMC offers faster response times but suffers from significant undershoot and higher steady-state errors. Conversely, SOSMC demonstrates superior performance with lower steady-state error, reduced ripple and significantly less harmonic distortion. These findings highlight the relative advantages and disadvantages of each control strategy, providing valuable insights for their application in both academic research and industrial practice.

This paper proposes a multi-objective model predictive control (MPC) for a grid-connected ten-switch three-phase three-level inverter. The main objective of the proposed MPC method is to control the grid current. In addition, the voltage balancing of the DC capacitors in the ten-switch three-level inverter is essential to generate voltage levels properly. Therefore, two objectives need to be achieved simultaneously. The multi-objective cost function feature of the MPC method is used to achieve these objectives. The simulation studies are performed using MATLAB/Simulink environments to investigate the effectiveness of the proposed MPC method. The results show that the proposed control method exhibits accurate performance under steady-state conditions and fast dynamic responses under transient conditions. Moreover, the grid current spectrums show that the total harmonic distortion is 2.21% in normal operation, and it is under the desired limits, even with a 50% parameter mismatch in filter inductance.

This paper presents an adaptive rate reaching law based sliding mode control method for a three-phase F-type converter. Unlike the existing reaching laws in which the gain is always constant, the proposed reaching law employs an adaptive gain that is continuously updated with the grid current errors. This means that the gain can reach to its smallest value when the grid current errors are zero. It is shown that the minimum gain reduces the reaching time. As a consequence of using adaptive gain, the dynamic response of system is improved considerably (i.e: the reaching time is reduced). Moreover, it is shown that the three-phase F-type converter can be operated as bidirectional battery charger as well as shunt active power filter (SAPF) for compensating the nonlinear loads connected at the point of common coupling. The proposed control and correct operation of system are validated by MATLAB/Simulink simulations under various operating conditions which include battery charging mode, battery discharging mode, and simultaneous operation as SAPF and battery charging/discharging.

This paper presents a hysteresis current control for single-phase single-stage buck-boost grid-connected inverters. The inverter topology employs four switches that are operated with the grid frequency and two bidirectional switches that are operated with high switching frequency. Hence, unlike the existing single-stage inverter topologies, the switching losses are minimized. Moreover, this inverter configuration has the capability to operate both in buck and boost modes and utilizes only a single inductor. The proposed hysteresis current control eliminates the need for designing a dedicated modulation technique for this inverter topology. An active damping technique is utilized to cope with the resonance damping problem without employing additional sensor. The reference current needed in the hysteresis controller is produced using a proportional-resonant (PR) controller whose input is the grid current error. The use of PR controller guarantees zero steady-state error in the grid current. The validity and superiority of the proposed control method are confirmed by MATLAB/Simulink simulations under various operating conditions which include buck mode, boost mode, transition from boost mode to buck mode, reference current change and virtual resistor variation. The simulation results show that the proposed control method is able to transfer the desired current into grid successfully under all operating conditions.

This paper proposes a hysteresis current control (HCC) method for a single-inductor buck-boost non-isolated onboard charger for electric vehicles. The charger is capable of working both in the boost and buck modes. The proposed HCC relies on the buck-boost inductor current and its reference which is generated using a proportional-resonant (PR) controller using grid current error. The reference current generated by PR controller is modified to suppress the oscillations in the inductor currents. An active damping by using a virtual resistor connected in series to filter inductor is used which does not require an additional sensor. A proportional-integral (PI) controller is used to generate the amplitude of grid current reference, which is utilized in constant current (CC) and constant voltage (CV) modes. The effectiveness of the proposed control strategy as well as the control method, is investigated by simulation studies by considering two different battery voltage levels (48V and 350V). The results show that the proposed method is able to charge the battery in CV and CC modes. Moreover, the grid current is maintained in unity power factor at a reasonably low total harmonic distortion (THD) which is smaller than the limits recognized by international standards.

This paper presents a passivity-based control approach for four-switch buck-boost (FSBB) DC-DC converters. The state variables are selected as the inductor current and the capacitor voltage errors. The passivity based control is formulated that targets to drive the inductor current and capacitor voltage to their reference values. The reference of the inductor current is produced by a proportional-integral controller that operates on the capacitor voltage error. Two control input equations are defined for buck and boost operations due to the fact that FSBB converter contains separate switches for buck and boost stages. As a consequence of controlling each stage by the dedicated control input, the passivity based control method eliminates the need for using a mode detection algorithm. The validity and superiority of the proposed approach has been studied by Matlab/Simulink simulations under load step, reference voltage step and operation mode variations for buck and boost modes. The results reveal that the proposed control approach can regulate the output voltage under all cases.

This paper proposes a super twisting sliding mode control for a bidirectional dual active bridge (DAB) converter. First of all, the mathematical model of the DAB converter developed around the Fourier expansion of the switching functions is defined and then a super twisting sliding function is proposed to regulate the output voltage while utilizing a sliding mode observer to estimate the load disturbance to get a feedforward term to the control input. On the contrary of the classical sliding mode control methods, the proposed sliding function is capable of alleviating the chattering while attaining zero steady state error and finite time convergence by estimating the load current and feedforwarding to the control loop. Since the control input is smooth, it can be directly injected to the PWM block for generating switching signals that cause fixed switching frequency. The effectiveness of the proposed method is verified in the MATLAB/ simulation software. The results confirm the disturbance rejection, fast response, and chattering alleviation of the proposed strategy thanks to the inherent characteristics of the super twisting method.

In this study, a current control strategy is proposed for nine-level packed-E-cell (PEC) rectifier without using current sensor. The proposed control strategy is based on mathematical model of rectifier. A modulation signal is obtained from the differential equation of the system. The modulation signal requires the inductor current reference whose amplitude is obtained by using a proportional-integral (PI) regulator. The input signal to the PI regulator is the dc load voltage error. Hence, while the grid current control is achieved by the proposed control, the regulation of load voltage is achieved by PI. The performance of the proposed control strategy is tested under load variations, reference load voltage change, and grid voltage variation. Moreover, the robustness of the proposed control method under inductance variations is also investigated. Computer simulations are conducted to show the steady-state and dynamic performances of the proposed control method.

This paper presents a weighting factor free Lyapunov-function-based model predictive control (MPC) for single-phase T-type rectifiers. The stability of the rectifier can be guaranteed if the derivative of Lyapunov function is negative. Motivated from this fact, the design of cost function (Lyapunov function) is based on stability of the rectifier. Since the coefficient used in the formulation of the Lyapunov function does not have any effect on the performance, the cost function becomes weighting factor free. The weighting factor free based MPC brings simplicity in the practical implementation. The performance of the proposed control technique has been investigated under normal and distorted grid voltage conditions during steady-state and transients caused by the load change. In all cases, the output and capacitor voltages are regulated at desired voltage levels, grid current tracks its reference and achieves unity power factor operation.

This article presents an indirect sliding mode control (SMC) for single-ended primary-inductor converters (SEPIC). Unlike the conventional SMC methods, the proposed SMC method employs a sliding surface function based on the input current error only. The use of such sliding surface function not only simplifies the implementation but also reduces the cost of implementation. It is shown that the output voltage control can be achieved indirectly. The input current reference is generated by a proportional-integral (PI) regulator. The existence condition and the region of the closed-loop system are determined for all possibilities of the PI gains. The performance of the proposed SMC method is investigated on a laboratory prototype converter, operated in buck and boost modes, in terms of the voltage regulation ability under abrupt changes in the input voltage and load resistance. Simulation and experimental results are presented and discussed.