A sustained effort is required to realize the aggressive targets of electrification of heavy equipment, e.g., the heavy-duty off-road vehicles, due to numerous emerging challenges, which are different from those in the automotive industry. Heavy equipment manufacturers are increasingly investing in new generation of power electronics technology to fulfill the high performance and reliability targets under harsh environments while reducing fuel consumption and staying cost competitive. In this work, a holistic power electronic circuits design is proposed to achieve 4× power density at 98% peak efficiency for a compact 250 kW three-phase three-level (3-L) T-type traction inverter. The proposed T-type inverter is designed using the best in class silicon carbide (SiC) power modules. Most importantly a multi-objective optimization approach to trade the volumetric power density (kW/l) against SiC device type (650, 900 and 1200 V), dc bus voltage, switching frequency, the size of the passives components. T-type inverter system design guidance is given in this work, including loss calculation, dc-link capacitor selection, thermal management solution, and bussing structure. In addition, the hardware-in-the-Ioop simulation study is performed to validate the performance of the control system designed for the traction inverter.

Various current ripple analysis methods have been proposed to evaluate the quality of output power of the power electronic converters. If performed in real-time, the current ripple analysis can lead to novel variable frequency pulse-width modulation methods. In this work, novel current ripple analysis and prediction approach for a three-phase 3-L T-type converter using space vector PWM (SVPWM) are proposed, including a comprehensive theoretical analysis for the relationship of the 3-L SVPWM and ripple generation. The proposed generalized current ripple prediction approach is accurate, easy to implement and feasible for practical applications. Then, the dead-time effect on the current ripple prediction is presented. Both simulation and experimental studies are performed to validate the feasibility and effectiveness of the proposed approach.

The trend and need of shifting towards renewable energy sources for electricity generation, has attracted researchers towards photovoltaic (PV) systems for last few decades. Since PV generator has nonlinear behavior, and its output power is a function of solar irradiance and ambient temperature, therefore need of developing maximum power point tracking (MPPT) techniques remains the interest. Among various MPPT techniques, Perturb & Observe (P&O) and Incremental-Conductance (IC) are dominant. This paper describes these two algorithms and compares them in terms of their computational complexity and oscillations near maximum power point (MPP) using MATLAB ^® & Simulink ^® . Also testing conditions are based on the real environmental data collected at NED University, Karachi.

Photovoltaic (PV) cell possesses non-linear power-voltage (P-V) characteristics. Maximum power point tracking (MPPT) techniques search the panel voltage at which maximum power can be achieved. In literature several converter topologies are used for testing and implementation of MPPT algorithm. These include buck, boost, buck-boost etc. Such implementations can't account for the efficiency of MPPT technique alone. This is due to the losses which could occur in different converter topologies. In this paper, a strategy which is based on an ideal converter, for testing the MPPT algorithms is proposed. Some of the major MPPT techniques are discussed and evaluated through the proposed strategy. Comparison among the MPPT algorithms is carried through MATLAB/Simulink. It is found that the proposed strategy is unbiased and suitable for testing MPPT algorithms.

A Multilevel Inverter (MLI) meets the power requirements of most power electronic applications. It can provide an AC supply with better power quality. The higher number of levels in an MLI results in better power quality output. The fundamental question that comes to mind is what the optimal number of levels can be in designing an MLI for better performance. This paper aims to provide a comparison of three-, five-, and seven-level schemes based on a “Diode Clamped MLI” and will analyze their performance on the reduction of Total Harmonic Distortion (THD).