Search

This paper investigates the influence of a constant carrier phase shift on the DC-link capacitor harmonic current of cascaded converters used in fuel-cell and mild-hybrid electric vehicles. In these applications, a DC-DC converter can be adopted between the battery and the motor drive inverter in a cascaded structure, where the two converters share the same DC-link. Since the DC-link capacitor of such a system represents a critical component, the optimization of the converter operation to limit the current stress and extend the lifetime of the capacitor is an primary objective. This paper proposes the use of a carrier phase shift between the modulations of the two converters in order to minimize the harmonic current of the DC-link capacitor. By harmonic analysis, an optimal carrier phase shift can be derived depending on the converter configuration. Analytical results are presented and validated by hardware-in-the-loop experiments. The findings show that the pulse width modulation carrier phase shift between the interleaved boost converter and the voltage source motor drive inverter has a significant influence on the DC-link capacitor current and thus on its lifetime. A case study with two-cell and three-cell interleaved boost converters shows a possible DC-link capacitor lifetime extension of up to 390%. [ABSTRACT FROM AUTHOR]

In response to climate change, governments around the world have committed to reducing greenhouse gas emissions, which contribute to global warming, through the energy transition from fossil fuels to renewable energy sources and electrification of transportation. This article outlines the design procedure for the electrification of a railway vehicle used for maintenance services on the rail network. The proposed methodology consists of the design of both an all-electric propulsion system and storage system with the aim of zero emissions when the vehicle is operating in tunnels and to minimise noise during maintenance services in cities. After highlighting the characteristics of the railway vehicle under consideration, a simulation model of the propulsion and generation system was developed in order to calculate the energy consumption of the entire railway system. Finally, experimental tests carried out on the prototype proved the effectiveness of the design procedure adopted and the proposed mathematical model, showing a good matching with the simulated results. [ABSTRACT FROM AUTHOR]

In recent years, a fast penetration of renewable sources in power electrical systems is taking place, providing many benefits; indeed, thanks to the Energy Community development, there is the possibility that renewable energy generated by a user can be shared by the other users of the community too. However, to make this happen, power electronics converters are the main characters of a proper management of shared energy. In this paper authors propose a Simulink scheme of an Energy Community, in which converters and related control systems have been modelled. Through the Maximum Power Point Tracking control of the photovoltaic converter, the maximum photovoltaic power is extracted, and through the double-loop control of the grid-connected inverter, only active power is fed into the grid, generating a current in phase with the grid voltage. The major innovation introduced in this paper is the modelling of a power sharing supervisor system that coordinates all the bidirectional converters which interface batteries to the community, according to their states of charge, in order to set power exchanges with the grid to zero. Results obtained from simulations demonstrate that, by varying load, photovoltaic production and batteries states of charge, the self-consumption optimization aim is pursued. [ABSTRACT FROM AUTHOR]

Conclusions All of the papers selected for this Special Issue have shown important insights and contributed to making this Special Issue successful in providing a platform for recent advances in the field of power electronics for electric drives and renewable energy sources, concerning both consumption and generation. This Special Issue was intended to consolidate the most recent advances in the field of power electronics for electric drives and renewable energy sources. In ref. [[3]], a design method for the cogging torque minimization of permanent magnet machines with a segmented stator core based on artificial neural network surrogate models is proposed. [Extracted from the article]

The cascaded H-bridge converter (CHB) is a very suitable solution with inherent modularity for many applications such as flexible ac transmission systems and motor drives. In this article, the discontinuous pulsewidth modulation (DPWM) by clamping some power cells is used in the CHB because it permits to reduce the switching losses in the power devices. However, this provokes a high harmonic distortion (basebands and sidebands harmonics) in the CHB output voltage compared with the quality obtained avoiding to clamp cells, just applying the conventional phase-shifted PWM (PS-PWM) technique. This has been studied for the three-cell CHB topology but the extension for an N-cell CHB with several clamped cells is a challenge that is addressed in this article. A generalized CHB harmonic voltage analysis applying the DPWM method is presented considering multiple clamped cells. The harmonic distortion mitigation target can be decoupled into two objectives. The proposed method cleverly groups the cells (one clamped + one or two nonclamped cells) to mitigate the basebands harmonic distortion. Simultaneously, a variable-angle PS-PWM technique is applied to the CHB in order to mitigate the sidebands harmonics content. Experimental results demonstrate the good performance of the proposed method. [ABSTRACT FROM AUTHOR]

Multilevel cascaded H-bridge (CHB) converters are an attractive solution for multiple applications like flexible ac transmission systems and solid-state smart transformers, among others. This article is focused on a CHB working with unbalanced conditions per cell (different cell dc voltages and/or cell voltage references). In this scenario, the phase-shifted pulsewidth modulation (PS-PWM) technique produces a harmonic distortion around twice the carrier frequency and its multiples in the CHB output voltage. In this article, a generalized variable-angle PS-PWM method is presented in order to mitigate this drawback improving the CHB output voltage harmonic spectrum. The proposed method is based on applying a mathematical search algorithm to determine the phase displacement angles to be applied to the PS-PWM technique. Experimental results show how this objective is achieved without introducing any disadvantage in the CHB operation. The method can be applied to CHB with any number of cells. [ABSTRACT FROM AUTHOR]

Currently, the necessity of efficient and reliable power systems is also increasing because of the strict requirements that standards and regulations impose, but still costs have to remain low. The monitoring and control of the components' lifetime can lead to reduce maintenance costs.However, overcoming the related challenges is not a straightforward task, as it involves knowledge of power device physics, smart management of electrical quantities, and optimal maintenance planning and scheduling. It represents a multidisciplinary issue being faced in the last decade. [ABSTRACT FROM AUTHOR]

Cascaded H-bridge converter (CHB) is a multilevel topology that is a well-suited solution for multiple applications such as flexible ac transmission systems or motor drives. This paper is focused on a CHB where the cells present an aging mismatch. This can be caused by the maintenance operation which forces the replacement of some damaged cells of the converter with new or repaired ones. In this paper, a new improved approach of the active thermal control (ATC) of the CHB using discontinuous pulsewidth modulation (PWM) (D-PWM) is presented. The D-PWM technique is used to reduce the power losses of one cell reducing its average temperature in order to increase its remaining lifetime. However, the combination of D-PWM with traditional phase-shifted PWM (PS-PWM) introduces high harmonic distortion in the output voltage of the CHB converter at twice the carrier frequency. A detailed harmonic distortion analysis of the CHB output voltage when the D-PWM based ATC is active is presented. From this analysis, a modification of the traditional PS-PWM is derived to eliminate the harmonic distortion at twice the carrier frequency. Experimental results show how the ATC using D-PWM is achieved whereas the harmonic distortion around twice the carrier frequency is eliminated. [ABSTRACT FROM AUTHOR]

In recent years, microgrids are becoming more widespread as a paradigm of energy generation and utilization. In this scenario, power electronic converters play a very important role as interface between the various sources and the various loads. This massive presence of such devices is arising issues related to their interaction, since they operate simultaneously. For this reason, research activity on how to drive them stably in such conditions is gaining more and more importance in order to guarantee reliable power exchange, continuous operation of microgrids and hence limitation of black-out occurrence. Nevertheless, the stable operation of grid-forming inverters is the most challenging task to be accomplished when it comes to feed some types of load whose presence is considered the main triggering factor for the electrical quantities to deviate from the set-point values thus leading the system to instability. To this end, this paper aims to present a control technique that is based on the theory of passivity and that can guarantee stable operation in one of the most critical operating conditions that occurs when a grid-forming inverter supplies constant power loads such as speed-controlled electric drives. These kinds of loads are very common on microgrids for industrial environments that can hence remarkably benefit from the proposed control technique. The results of the simulation tests prove the effectiveness of the proposed control technique in stably operating the considered system also in presence of parameters variation. [ABSTRACT FROM AUTHOR]

The use of fast wide-bandgap devices in high-speed electrical drives with steep pulsewidth modulation voltage waveforms is the main cause of increased stress on the electric machine insulation system and consequently, of reduced reliability of the whole system. This represents a major concern in safety-critical applications, such as in the aerospace and electric transportation fields. The novel contribution of this work is to assess the effects of electrical aging on complex insulation systems (i.e., a whole stator winding) by analyzing easily measurable macroscopic quantities. To this purpose, an electrical aging procedure is defined, and the effects produced on three tested motors are presented. Three different analysis methods are adopted with the aim of assessing the damage caused to an ac motor winding by such steep voltage waveforms and hence to evaluate the state of aging of the insulation system. [ABSTRACT FROM AUTHOR]

High-speed electrical drives normally require converters capable of high-frequency operation. For this reason, converters based on SiC mosfets have been spreading in this field. Nevertheless, the problems caused by the high dv/dt imposed by SiC mosfets, like the premature failure of the motor winding insulation and the electromagnetic interference generation, are drawing more and more attention of the experts of this sector. In fact, these issues can deeply affect the system reliability and, hence, can represent a limiting factor for all those applications where the continuity of operation is the highest priority. To avoid the use of SiC mosfets in the most sensitive applications, this paper presents a solution, which consists of a Si-insulated gate bipolar transistor (IGBT)-based inverter fed by a Si-IGBT-based dc/dc converter performing a suitable dc voltage regulation. Therefore, the aim of this paper is to prove that a stable operation of a high-speed drive can be guaranteed through the proposed converter configuration. To prove the effectiveness of the proposed solution, experimental results on a laboratory setup have been presented. [ABSTRACT FROM AUTHOR]

Among multilevel converter topologies, the cascaded H-bridge (CHB) converter is one suitable solution for multiple applications, such as flexible ac transmission systems and motor drives. CHB presents a natural high modularity because it is formed by the serial connection of H-bridges. This paper deals with a CHB where the cells do not have the same aging because the maintenance during the years of operation forces to replace some damaged cells of the converter with new or repaired ones. A method based on clamping one power cell can be used to reduce the power losses of that cell reducing its temperature and increasing its lifetime. However, clamping one cell of the CHB introduces high harmonic distortion around twice the carrier frequency due to the CHB unbalanced operation when a conventional phase-shifted pulsewidth modulation (PWM) is applied. A deep harmonic distortion analysis of the CHB output voltage with thermal control based on clamping one cell is presented. Using this analysis, the harmonic distortion at twice the carrier frequency is eliminated applying a nonconventional phase-shifted PWM where the angles between the carriers of consecutive power cells are modified. Experimental results show how the thermal control applying the clamping of a power cell is achieved while the harmonic distortion around twice the carrier frequency is eliminated. [ABSTRACT FROM AUTHOR]

This study considers the design of surface-mounted permanent magnet electrical machines for high-speed applications and proposes a methodology to determine the maximum achievable power density. Power density is usually improved by increasing rotational speed. At high speed, a mechanical retaining system for the rotor magnets must be considered. As the speed increases, the thickness of the retaining sleeve becomes larger, reducing torque capability. There will be an optimal speed at which the output power will be maximised. Both structural and electromagnetic design must be considered simultaneously to properly address this design problem. To simplify the design procedure, static finite-element simulations are used for the electromagnetic analysis and analytical formulae are employed for retaining sleeve sizing. The procedure is aided by multi-objective optimisation algorithms. A case study based on the specification of an aeronautical actuator is presented. The performances that can be obtained using different iron cores, high-grade silicon steel, and cobalt iron steel are compared. Finally, results obtained from transient finite-element electromagnetic and structural analysis are presented to validate the feasibility of the proposed procedure. [ABSTRACT FROM AUTHOR]

This study considers the design of surface‐mounted permanent magnet electrical machines for high‐speed applications and proposes a methodology to determine the maximum achievable power density. Power density is usually improved by increasing rotational speed. At high speed, a mechanical retaining system for the rotor magnets must be considered. As the speed increases, the thickness of the retaining sleeve becomes larger, reducing torque capability. There will be an optimal speed at which the output power will be maximised. Both structural and electromagnetic design must be considered simultaneously to properly address this design problem. To simplify the design procedure, static finite‐element simulations are used for the electromagnetic analysis and analytical formulae are employed for retaining sleeve sizing. The procedure is aided by multi‐objective optimisation algorithms. A case study based on the specification of an aeronautical actuator is presented. The performances that can be obtained using different iron cores, high‐grade silicon steel, and cobalt iron steel are compared. Finally, results obtained from transient finite‐element electromagnetic and structural analysis are presented to validate the feasibility of the proposed procedure. [ABSTRACT FROM AUTHOR]

This paper analyzes the performances of different carrier phase-shifting pulse width modulation (PWM) techniques to be used with a multilevel cascaded H-bridge converter in case of unbalanced operational conditions. In fact, in many practical applications, the ideal condition of equal dc voltages and equal reference signals for each H-bridge cannot be achieved. In such conditions, the conventional carrier phase-shifting PWM technique loses its harmonic canceling capabilities and then the multilevel ac voltage harmonic quality is deeply affected. To overcome this limit of the original technique, different variations have been proposed. All of them still rely on the carrier phase-shifting concept and propose to use a different value of the shifting angle for each carrier (unlike the original technique) whenever unbalanced operational conditions occur. In this paper, the three main solutions proposed over the last years to extend the capabilities of the carrier phase-shifting PWM technique are compared. The analysis is focused on a three-cell cascaded H-bridge converter. Simulation and experimental results are presented. [ABSTRACT FROM PUBLISHER]

This paper considers the electromagnetic and structural co-design of superficial permanent magnet synchronous machines for high-speed applications, with the aid of a Pareto optimization procedure. The aim of this work is to present a design procedure for the afore-mentioned machines that relies on the combined used of optimization algorithms and finite element analysis. The proposed approach allows easy analysis of the results and a lowering of the computational burden. The proposed design method is presented through a practical example starting from the specifications of an aeronautical actuator. The design procedure is based on static finite element simulations for electromagnetic analysis and on analytical formulas for structural design. The final results are validated through detailed transient finite element analysis to verify both electromagnetic and structural performance. The step-by-step presentation of the proposed design methodology allows the reader to easily adapt it to different specifications. Finally, a comparison between a distributed-winding (24 slots) and a concentrated-winding (6 slots) machine is presented demonstrating the advantages of the former winding arrangement for high-speed applications. [ABSTRACT FROM AUTHOR]

This paper presents an efficiency comparison of two converters designed for driving high-speed AC machines. In such applications, an inverter based on Si- IGBTs is not a viable solution since the switching losses became too high and physical limits of such devices do not match the required elevated switching frequencies. The use of SiC devices allows higher switching frequencies and reduced losses but issues mainly related to quickened motor insulation aging arise because of high dv/dt values. In this work a topology, made up of a Si IGBT inverter fed by a SiC MOSFET DC-DC converter, is benchmarked over an inverter based on SiC MOSFETs in terms of efficiency. The advantage of the first solution is to reduce the switching frequency and the dv/dt values without reducing the control frequency. Therefore, the major result is to lower the stress on the motor winding insulation. To assess and compare the efficiency performances of the two schemes, simulation and experimental tests have been carried out. Results show the feasibility of the proposed solution. [ABSTRACT FROM AUTHOR]

This paper describes a detailed design procedure for passivity-based controllers developed using the Brayton–Moser (BM) framework. Several passivity-based feedback designs are presented for the voltage-source converter, specifically for the H-bridge converter, since nowadays it is one of the preferred solutions to connect direct current (dc) loads or distributed sources to the alternating current (ac) grid. Independent of the operating mode, namely, the rectifier and regenerative operating mode, the achieved control aims are: high power factor correction in the ac-side and optimal dc voltage regulation capability in the dc-side. The proposed controllers can use series or parallel damping-based solutions for the error dynamics, naturally providing the conditions for stability and tuning of control parameters. In addition, the BM structure facilitates the addition of virtual resistance-inductance-capacitance (RLC) filter circuits to the control design for the rejection of low frequency harmonics. The effectiveness of series/parallel damping is investigated in case of abrupt changes in the load, using conductance estimators. Simulation and experimental results validate the analysis. [ABSTRACT FROM AUTHOR]

The insulation system's dielectric of the electric motor is very often subjected to severe electrical stress generated by the high d v / d t seen at the machine's terminals. The electrical stress and high reflected wave transient overvoltage are even more evident in case of high-speed machines fed by high-frequency (HF) converters featuring very fast wide-bandgap devices. They are promoting the occurrence of partial discharges and consequently accelerate ageing. As this is serious issue and the main cause of the drive failure, it is important to analyse and characterise the surges at the motor terminals. Several HF models of motors have been proposed in the literature for this purpose. This article presents a survey on HF motor models, which is crucial in understanding and studying the most critical parameter identification and overvoltage mitigation techniques. Moreover, it offers a comparison of the models' main features as well as a comparison with the experimental voltage waveform at motor terminals. A general overview of the partial discharge (PD) phenomenon is also provided, as it is favoured by HF operation and together with HF motor modelling provides key insights to the insulation ageing issue. In particular, an analysis of the effects of PWM waveform affecting insulation is given, as well as useful methods for developing strategies for the inspection and maintenance of winding insulation. [ABSTRACT FROM AUTHOR]

The H-bridge-based multilevel active rectifier is an attractive topology that allows feeding of multiple dc loads. The main control problem is to manage n + 1 state variables (one current plus n dc voltages) with only n switching functions. In this paper, three PI-based solutions are discussed, and the tuning of the best solution is addressed in case resonant controllers are used instead of classical integrators. Moreover, practical problems such as the implementation and the influence of phase-locked-loop systems and of analog filters (first order and Butterworth) on the measurements are discussed. [ABSTRACT FROM AUTHOR]

In this paper, a new low-frequency predictive current control is proposed for a single-phase cascaded H-bridge multilevel rectifier. The control method has been fully investigated with theoretical analysis, simulation, and experiments on a laboratory prototype with five series-connected H-bridges. However, the analysis and technique are valid for any general N-level structure. The simulations and experimental results presented demonstrate the excellent performance of the predictive control in terms of ac current waveform quality, power factor, and reduced switching frequency of each bridge, in comparison to traditional control schemes. [ABSTRACT FROM AUTHOR]

This paper deals with the control of a multilevel n-H-bridges front-end rectifier. This topology allows n distinct dc buses to be fed by the same ac source offering a high loading flexibility suitable for traction applications as well as for industrial automation plants. However, this flexibility can lead the system to instability if the dc buses operate at different voltage levels and with unbalanced loads. Thus, linear controllers, designed on the basis of the small-signal linearization, are not effective any longer and stability can not be ensured as large-signal disturbances occur. The use of a passivity-based control (PBC) designed via energy considerations and without small-signal linearization properly fits stability problems related to this type of converter. The system has been split into n subsystems via energy considerations in order to achieve the separate control of each dc bus and its stability in case of load changes or disturbances generated by other buses. Then, a set of n passivity-based controllers (one for each subsystem) is adopted: the controllers are linked using dynamical parameters computed through energy balance equations. Hence, the system dc buses are independent and stable as experimental results demonstrate. [ABSTRACT FROM AUTHOR]

Power-quality monitoring is a very complex task and recently it is assuming a growing importance because of the large diffusion of nonlinear and time-varying single-phase and three- phase loads and their interactions with the power supply system. A set of two indexes capable of evaluating the power quality at the point of common coupling (PCC) in terms of harmonic distortion and unbalance is proposed in this paper. By means of these new performance parameters, which are based on voltage and current waveform measurements at the PCC, it is possible not only to evaluate separately unbalance and distortion, but also to localize polluting loads and separate the responsibilities of distributors and customers. Numerical simulations and experimental tests prove the effectiveness of the presented indexes and their tow sensitivity to the network voltage conditions compared with the traditional ones. [ABSTRACT FROM AUTHOR]

This paper focuses on the design of a controller for a high-voltage high-power single-phase active rectifier, designed for, but not limited to, traction field applications. The rectifier should absorb current with low harmonic content to reduce the environmental electromagnetic pollution and to eliminate the disturbances to the on-board communication equipment. In addition, it should allow the elimination of the heavy and bulky transformer, reducing encumbrance and cost. A multilevel H-bridge single-phase configuration has been chosen and the design has been fully investigated with the help of theoretical analysis, simulations, and experiments. [ABSTRACT FROM AUTHOR]

The control of a single-phase multilevel H-bridge rectifier suitable for traction applications is considered. Such a converter often presents instability problems making difficult its design and uncertain its behavior. In this paper the use of a passivity-based controller is experimentally investigated. Such a controller achieves stability, unity power factor, good balancing between the two dc links, and satisfactory behavior even in the presence of load changes. A right choice of the damping parameters allows the fulfilling of system requirements in terms of dc-link voltage error and grid current distortion. [ABSTRACT FROM AUTHOR]

Electric variable speed drives (VSD) have been replacing mechanic and hydraulic systems in many sectors of industry and transportation because of their better performance and reduced cost. However, the electric systems still face the issue of being considered less reliable than the mechanical ones. For this reason, researchers have been actively investigating effective ways to increase the reliability of such systems. This paper is focused on the analysis of the common-mode voltage (CMV) generated by the operation of the VSDs which directly affects to the lifetime and reliability of the complete system. The method is based on the mathematical description of the harmonic spectrum of the CMV depending on the PWM method implementation. A generalized PWM method where the carriers present a variable phase-displacement is developed. As a result of the presented analysis, the CMV reduction is achieved by applying the PWM method with optimal carrier phase-displacement angles without any external component and/or passive filtering technique. The optimal values of the carrier phase-displacement angles are obtained considering the minimization of the CMV total harmonic distortion. The resulting method is easily implementable on mostly off-the-shelf mid-range micro-controller control platforms. The strategy has been evaluated in a scaled-down experimental setup proving its good performance. [ABSTRACT FROM AUTHOR]

Permanent magnet machines with segmented stator cores are affected by additional harmonic components of the cogging torque which cannot be minimized by conventional methods adopted for one-piece stator machines. In this study, a novel approach is proposed to minimize the cogging torque of such machines. This approach is based on the design of multiple independent shapes of the tooth tips through a topological optimization. Theoretical studies define a design formula that allows to choose the number of independent shapes to be designed, based on the number of stator core segments. Moreover, a computationally-efficient heuristic approach based on genetic algorithms and artificial neural network-based surrogate models solves the topological optimization and finds the optimal tooth tips shapes. Simulation studies with the finite element method validates the design formula and the effectiveness of the proposed method in suppressing the additional harmonic components. Moreover, a comparison with a conventional heuristic approach based on a genetic algorithm directly coupled to finite element analysis assesses the superiority of the proposed approach. Finally, a sensitivity analysis on assembling and manufacturing tolerances proves the robustness of the proposed design method. [ABSTRACT FROM AUTHOR]

This paper proposes a new variable structure control scheme for a variable-speed, fixed-pitch ducted wind turbine, equipped with an annular, brushless permanent-magnet synchronous generator, considering a back-to-back power converter topology. The purpose of this control scheme is to maximise the aerodynamic power over the entire wind speed range, considering the mechanical safety limits of the ducted wind turbine. The ideal power characteristics are achieved with the design of control laws aimed at performing the maximum power point tracking control in the low wind speeds region, and the constant speed, power, and torque control in the high wind speed region. The designed control laws utilize a Luenberger observer for the estimation of the aerodynamic torque and a shallow neural network for wind speed estimation. The effectiveness of the proposed method was verified through tests in a laboratory setup. Moreover, a comparison with other solutions from the literature allowed us to better evaluate the performances achieved and to highlight the originality of the proposed control scheme. [ABSTRACT FROM AUTHOR]

Widespread dissemination of electric mobility is highly dependent on the power converters, storage systems and renewable energy sources. The efficiency and reliability, combined with the emerging and innovative technologies, are crucial when speaking of power converters. In this paper the interleaved dc–dc topology has been considered for EV charging, due to its improved reliability. The efficiency comparison of the SiC-MOSFET and Si-IGBT-based converters has been done on wide range of switching frequency and output inductances. The interleaved converters were considered with the optimal switching parameters resulting from the analysis done on a detailed parasitic circuit model, ensuring minimum losses and maintaining the safe operating area. The analysis included the comparison of different inductors, and for the selected ones the complete system efficiency and cost were conducted. The results indicate the benefits when SiC-MOSFETs are applied to the interleaved dc–dc topology for wide ranges of output inductances and switching frequencies, and most importantly, they offer lower total volume but also total cost. The realistic and dynamic models of power devices obtained from the manufacturer's experimental tests have been considered in both LTspice and PLECS simulation tools. [ABSTRACT FROM AUTHOR]

Wide bandgap (WBG) power devices such as silicon carbide (SiC) can viably supply high speed electrical drives, due to their capability to increase efficiency and reduce the size of the power converters. On the other hand, high frequency operation of the SiC devices emphasizes the effect of parasitics, which generates reflected wave transient overvoltage on motor terminals, reducing the life time and the reliability of electric drives. In this paper, a SiC metal-oxide-semiconductor field-effect transistor (MOSFET) based two level (2L) inverter is systematically studied and compared to the performance of Si insulated-gate bipolar transistor (IGBT) based three level (3L) neutral point clamped (NPC) inverter topologies, for high speed AC motor loads, in terms of efficiency, overvoltages, heat sink design, and cost. A fair comparison was introduced for the first time, having the same output voltage capabilities, output current total harmonic distortion (THD), and overvoltages for the three systems. The analysis indicated the convenience of using the SiC MOSFET based 2L inverter for lower output power. In the case of the maximum output power, the heat sink volume was found to be 20% higher for the 2L SiC based inverter when compared to 3L NPC topologies. Simulations were carried out by realistic dynamic models of power switch modules obtained from the manufacturer's experimental tests and verified both in the LTspice and PLECS simulation packages. [ABSTRACT FROM AUTHOR]