The impact of GaN mosfet and the performance of three-phase traction inverter for electric vehicles are closely investigated in this paper. Two versions of inverter have been illustrated: first one with Si-IGBTs, whereas the second one is built with GaN-mosfets with similar rating of voltage and current. The loss model is expounded for both the inverters; thereafter total losses are calculated considering New European Driving Cycle profile along the speed and torque of the permanent magnet synchronous motors. Further, for close-loop operation of propulsion drive, predictive current controller is proposed and compared with conventional PI controller while to control the speed, only PI controller is used. Moreover, the losses of both types of inverters are compared and the compared result confirmed that the inverter built up with GaN-mosfets with proposed current controller increases the efficiency of the propulsion drive leads to enhancement in driving range of the vehicles.

Bidirectional dc–dc converter (BDC) is an integral part of energy storage interface, where high efficiency, high voltage transfer ratio and small input ripple current are essential for application, such as dc microgrid and electric vehicle. In this article, a new approach is proposed to achieve reduced input ripple current at the low voltage side, which potentially replaces the necessity of using interleaved circuit structure. Parallel coupled inductor and capacitor circuit are utilized for charging and discharging the two parallel paths in a complementary fashion using a mosfet . The proposed solution helps to increase the voltage conversion ratio unlike interleaved structure. Additionally, in proposed BDC, zero voltage switching turn on operation of all active switches are possible utilizing synchronous rectification principle in both the operating modes. Parallel path structure not only reduce the input current ripple, but also helps to share the input current, thereby reducing the coil size and associated losses. A 250 W BDC is designed to validate performance in 1kW dc microgrid system

This paper presents a novel switch current stress reduction technique for a single switch boost-fly-back high step up dc-dc converter. Coupled inductor based converters do not have sufficiently higher inductance value of their windings. This creates current surge during transient and steady state, which in turn increases current stress at main switch. To compensate this difficulty in coupled inductor based boost fly back converter, an inductor - diode parallel combination has been connected in series with the switch. This technique increases the effective inductance of the coupled inductor primary winding during Switch turn ON operation and helps to reduce current stress. Steady state operating principle with proposed technique is analyzed in CCM. The current reduction technique is discussed with a proper mathematical derivation. To verify theoritical findings simulation study is carried out in MATLAB/Simulink R2014b. Lastly laboratory based 40 W protopype converter is designed to show the effectiveness of the proposed switch current reduction technique.

Brushless DC (BLDC) motors are widely used in various low‐power drive applications owing to their several advantages over conventional motors. This study describes a fuzzy logic‐based improved loss minimisation technique for the BLDC motor drive system. The proposed algorithm uses selective harmonic elimination‐based pulse‐width modulation to optimise both the converter switching losses along with machine core and copper losses based on a speed‐ and load‐dependent fuzzy rule matrix. The optimum switching angles eliminating lower‐order harmonics are calculated offline and stored in microcontroller memory for online application. The suitability of the proposed control is well demonstrated through simulation and experimental results on a practical 350 W BLDC machine.

This paper shows the effectiveness of adaptive terminal sliding mode control in grid connected hybrid solar PV and wind system for improvement in error tracking performance under different disturbances. Lead acid battery arrangement is made to support hybrid system. To analyze hybrid system, d-q axis circuit models are independently derived for both PMAC (Permanent Magnet AC) generator and inverter. An adaptive lyapunov based rapid terminal sliding mode control is superior over the traditional PI control because of its faster error tracking capability and robustness. Q-V based inverter control is employed to interface single phase grid and the hybrid system. To substantiate the proposed theory a number of case studies have been conducted like parametric changes of converters, inverter and the changes occurring in the hybrid system. Experimental results of proposed control are obtained from a laboratory prototype of 250 W PMAC and 500W PV hybrid module with 100 ampere-hour battery system. Small-signal stability at different disturbance points are analyzed using dynamic simulations on MATLAB/Simulink.2014R(b). Real time controller is implemented through programming in Lab-VIEW on NI c-RIO 9082.