Journal of Power Electronics, Vol. 17, No. 4, pp. 1097-1108, July 2017 1097 https://doi.org/10.6113/JPE.2017.17.4.1097 ISSN(Print): 1598-2092 / ISSN(Online): 2093-4718 JPE 17-4-24 Applicable Method for Average Switching Loss Calculation in Power Electronic Converters Seyyed Abbas Saremi Hasari * , Ahmad Salemnia † , and Mohsen Hamzeh * *, † Faculty of Electrical Engineering, Shahid Beheshti University, Tehran, Iran Abstract Accurate calculation of the conduction and switching losses of a power electronic converter is required to achieve the efficiency of the converter. Such calculation is also useful for computing the junction temperature of the switches. A few models have been developed in the articles for calculating the switching energy losses during switching transitions for the given values of switched voltage and switched current. In this study, these models are comprehensively reviewed and investigated for the first time for ease of comparison among them. These models are used for calculating the average amount of switching power losses. However, some points and details should be considered in utilizing these models when switched current or switched voltage presents time-variant and alternative quantity. Therefore, an applicable technique is proposed in details to use these models under the above-mentioned conditions. A proper switching loss model and the presented technique are used to establish a new and fast method for obtaining the average switching power losses in any type of power electronic converters. The accuracy of the proposed method is evaluated by comprehensive simulation studies and experimental results. Key words: Analytical loss model, Conduction loss model, Power electronic converter loss, Switching loss model I. INTRODUCTION Power electronic converters play an important role in the electric power industry because of their applications, such as integrating the distributed energy units into the grid [1], improving the power quality of the grid [2], and driving the electric motors. Electrical power loss is an important concern of power electronic converters. Converter losses usually involve the power losses of the electromagnetic devices and the power losses of the semiconductor switches. Switch power losses consist of three parts: 1) switching losses, 2) conduction losses, and 3) negligible off-state losses. The switching losses are dominant losses at high switching frequencies and depend on four factors [3]: 1) switched voltage, 2) switched current, 3) switching frequency, and 4) rising and falling times of the switch voltage and current. The switching losses are more difficult to calculate, in comparison with the conduction losses [4]. The difficulty is attributed to the tiny amount of the turn-on and turn-off transition times, and the estimation of switch waveforms during transition times that needs to provide the accurate model of the switch. Calculating the conduction and switching losses of a power electronic converter is useful for 1) calculating the junction temperature of the switches for designing the heat sink, and 2) obtaining the efficiency of the converter. Efficiency is an important characteristic of power electronic converters and is thus used as an evaluation criterion for five types of DC/AC converters in [5], for two types of AC/AC converters in [6], and for photovoltaic inverters in [7]. The switching losses of the converters can be calculated by three methods [8], [9]: 1) utilizing experimental switching waveforms acquired from the laboratory prototype, 2) utilizing simulation models obtained by the switch datasheet and its electrical and thermal models, and 3) using analytical models. Unlike the analytical methods, simulation-based methods require calculating the switching energy losses for all the turn-on and turn-off transitions. Analytical methods can be derived when the output current is sinusoidal. In these methods, the average switching power loss is calculated using some information, such as switch characteristics, output displacement factor, amplitude of the output current, and modulation index. Therefore, simulation-based methods exhibit more computational burden compared to analytical methods. However, simulation-based methods can be implemented for all kinds of converters and output currents. Manuscript received Oct. 3, 2016; accepted May 8, 2017 Recommended for publication by Associate Editor Hyung-Min Ryu. † Corresponding Author: a_salemnia@sbu.ac.ir Tel: +982173932502, Fax: +982177310425, Shahid Beheshti University * Faculty of Electrical Engineering, Shahid Beheshti University, Iran © 2017 KIPE