0093-9994 (c) 2017 IEEE. Personal use is permitted, but republication/redistribution requires IEEE permission. See http://www.ieee.org/publications_standards/publications/rights/index.html for more information. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. Citation information: DOI 10.1109/TIA.2017.2785759, IEEE Transactions on Industry Applications 1 A GUIDE TO MATCHING MEDIUM VOLTAGE DRIVE TOPOLOGY TO PETROCHEMICAL APPLICATIONS Navid Zargari, Ph.D., P.Eng Zhongyuan Cheng, Ph.D. Rick Paes, P.Eng Fellow, IEEE Member, IEEE Senior Member, IEEE Rockwell Automation Rockwell Automation Rockwell Automation 135 Dundas St. 135 Dundas St P.O. Box 3 Cambridge, ON Cambridge ON Calgary, AB Canada N1R 5X1 Canada N1R 5X1 Canada nrzargari@ra.rockwell.com gcheng@ra.rockwell.com rpaes@ra.rockwell.com Abstract – Medium voltage drives are regularly used in the petrochemical industry. These drives often vary in topology, semiconductor design and principles of operation. They each have their own merits, not only in terms of structure, design and reliability, but also with regard to suitability to specific applications. This paper presents a technology overview of commercially available medium voltage drive topologies with a view on how they match to petrochemical applications. The operating and performance characteristics of each drive topology are reviewed while manufacturer-specific implementation details are excluded. Common industry and application requirements such as harmonics, motor compatibility, regeneration capability, dynamic performance and robustness to system power disturbances are used as comparison criteria. Application aspects such as commissioning and operation challenges are highlighted from a practical point of view. Index Terms — Medium voltage (MV) drives, high-power converter, voltage source inverter, current source inverter, Cascaded H-Bridge (CHB) converter, Neutral Point Clamped (NPC) converter, Cascaded NPC (CNPC) converter, Active NPC converter (ANPC), Adjustable Speed Drive (ASD) I. INTRODUCTION High-power converters used in medium voltage drives can be categorized from various points of view [1]-[10]. A simple approach is a categorization based on the characteristics of the DC link (the main storage element). Using this approach, three main genre of high-power converters exist: 1. those achieving the AC-to-AC conversion without the need of a DC energy storage stage, i.e. matrix converters; 2. those requiring a capacitive DC storage element also known as voltage source type; and 3. topologies that require an inductor as their main DC storage element, or current source type. This categorization is shown in Fig. 1 in addition to a further categorization based on modularization amongst the voltage source topologies. The research in finding the most suitable medium voltage topology continues and new variations or hybrid mutations of the above topologies surface. But, not all these topologies are commercialized. The focus of this paper is to look at the topologies that are commercialized as an MV drive, review and highlight their differences and identify their suitability when used in petrochemical applications. We have considered six topologies that are most commonly used, and this article can serve as a reference that highlights the most salient characteristics of these topologies. These six topologies are highlighted in Fig. 1 by shaded boxes. They are: - Current Source Inverter with PWM Current Source Rectifier (PWM CSR-CSI) - Cascaded H-Bridge (CHB) Converter - Neutral Point Clamped (NPC) Converter - Active Neutral Point Clamped (ANPC) Converter (5 level selected) - Cascaded Neutral Point Clamped (CNPC) Converter - Modular Multilevel Converter (MMC) For the rest of this paper these topologies will be referred to with their designated abbreviations. Fig. 1 Categorization of high-power converters used in MV applications High Power Converters No DC stage Matrix Converter Cascaded Matrix Converter Current Source type (inductor DC stage) LCI PWM CSI Voltage Source type (capacitor DC stage) Interconnected DC midpoint Neutral Point Clamped Neutral Point Piloted Nested NPC Active NPC Hybrid Cascaded NPC Modular design Cascaded H Bridge Modular Multilevel Converter