Common-Mode Overvoltage Mitigation in a Medium-Voltage Pump Motor Transformerless Drive in a Mining Plant

The mining process requires different types of pumps to transfer fluids from one point to another. In the majority of applications, those pumps are driven by variable speed motor drives in order to improve the energy efficiency of the overall system. Large pumps, ranging from hundreds of kW to a few MW, usually demand medium-voltage converters. Transformerless converters reduce the footprint required for the installation, but give rise to additional concerns related to the common-mode voltages applied to the system and motor. The absence of an isolation transformer along with the use of pulse-width modulated rectifiers are the root causes of this issue. This concern increases when long cables are needed to connect the converter to the motor. This paper presents an application where three-level neutral point clamped transformerless medium-voltage converters are applied to drive motor pumps in a mining plant. The passive filtering techniques used to address the common-mode voltage issues are analyzed through simulations. The proposed solutions are field tested with successful results.

[1]  S. D. Pekarek,et al.  Equivalent circuits for common-mode analysis of naval power systems , 2015, 2015 IEEE Electric Ship Technologies Symposium (ESTS).

[2]  T.A. Lipo,et al.  A reduced common mode hysteresis current regulation strategy for multilevel inverters , 2003, Eighteenth Annual IEEE Applied Power Electronics Conference and Exposition, 2003. APEC '03..

[3]  Thomas A. Lipo,et al.  An inverter/motor drive with common mode voltage elimination , 1997, IAS '97. Conference Record of the 1997 IEEE Industry Applications Conference Thirty-Second IAS Annual Meeting.

[4]  H. Akagi,et al.  Suppression of common-mode voltage in a PWM rectifier/inverter system , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[5]  E. Persson,et al.  Transient effects in application of PWM inverters to induction motors , 1991, Conference Record of 1991 Annual Pulp and Paper Industry Technical Conference.

[6]  H. Akagi,et al.  Modeling and damping of high-frequency leakage currents in PWM inverter-fed AC motor drive systems , 1995, IAS '95. Conference Record of the 1995 IEEE Industry Applications Conference Thirtieth IAS Annual Meeting.

[7]  Ahmet M. Hava,et al.  Simple Analytical and Graphical Methods for Carrier-Based PWM-VSI Drives , 1999 .

[8]  Prasad Enjeti,et al.  Analysis of common mode voltage-"neutral shift" in medium voltage PWM adjustable speed drive (MV-ASD) systems , 2000 .

[9]  Steven D. Pekarek,et al.  Derivation and Application of Equivalent Circuits to Model Common-Mode Current in Microgrids , 2017, IEEE Journal of Emerging and Selected Topics in Power Electronics.

[10]  R. M. Tallam,et al.  System Design of Adjustable Speed Drives, Part 1: Equipment and Load Interactions , 2012, IEEE Industry Applications Magazine.

[11]  Prasad Enjeti,et al.  A method to reduce common mode and differential mode dv/dt at the motor terminals in PWM rectifier/PWM inverter type adjustable speed drive systems , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[12]  J. Pontt,et al.  Resonances and overvoltages in a medium voltage fan motor drive with long cables in an underground mine , 2004, Conference Record of the 2004 IEEE Industry Applications Conference, 2004. 39th IAS Annual Meeting..

[13]  D.A. de Andrade,et al.  Methodology for Cable Modeling and Simulation for High-Frequency Phenomena Studies in PWM Motor Drives , 2008, IEEE Transactions on Power Electronics.

[14]  Haihui Lu,et al.  Analytical investigation of the switching frequency harmonic characteristic for common mode reduction modulator , 2005, Fourtieth IAS Annual Meeting. Conference Record of the 2005 Industry Applications Conference, 2005..

[15]  Thomas A. Lipo,et al.  Active filtering for common mode conducted EMI reduction in voltage source inverters , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.

[16]  H. Akagi,et al.  A Passive EMI Filter for Eliminating Both Bearing Current and Ground Leakage Current From an Inverter-Driven Motor , 2005, IEEE Transactions on Power Electronics.

[17]  B. C. Cardoso Filho,et al.  Analysis of passive filters for high power three-level rectifiers , 2008, 2008 34th Annual Conference of IEEE Industrial Electronics.

[18]  H. de Paula,et al.  Characterization of cable arrangements in terms of the generated high-frequency quantities in PWM motor drives , 2009, 2009 Brazilian Power Electronics Conference.

[19]  R. M. Tallam,et al.  System Design of Adjustable Speed Drives, Part 2: System Simulation and ac Line Interactions , 2012, IEEE Industry Applications Magazine.

[20]  T. Lipo,et al.  Elimination of common mode voltage in three phase sinusoidal power converters , 1996, PESC Record. 27th Annual IEEE Power Electronics Specialists Conference.

[21]  Braz De J. Cardoso Filho,et al.  Common-mode overvoltage mitigation in a medium voltage pump motor transformerless drive in a mining plant , 2016, 2016 IEEE Industry Applications Society Annual Meeting.

[22]  Poh Chiang Loh,et al.  Reduced common-mode modulation strategies for cascaded multilevel inverters , 2003 .

[23]  A. von Jouanne,et al.  Application issues for PWM adjustable speed AC motor drives , 1996 .

[24]  R A Lukaszewski,et al.  Common-Mode Voltage Reduction PWM Algorithm for AC Drives , 2010, IEEE Transactions on Industry Applications.

[25]  Braz de Jesus Cardoso Filho,et al.  Current control of three level neutral point clamped voltage source rectifiers using selective harmonic elimination , 2014, IECON 2014 - 40th Annual Conference of the IEEE Industrial Electronics Society.

[26]  T.A. Lipo,et al.  High frequency modeling for cable and induction motor overvoltage studies in long cable drives , 2001, Conference Record of the 2001 IEEE Industry Applications Conference. 36th IAS Annual Meeting (Cat. No.01CH37248).

[27]  D. Casadei,et al.  Common- and differential-mode HF current components in AC motors supplied by voltage source inverters , 2004, IEEE Transactions on Power Electronics.

[28]  Anderson V. Rocha,et al.  Premature Wear and Recurring Bearing Failures in an Inverter-Driven Induction Motor—Part II: The Proposed Solution , 2013, IEEE Transactions on Industry Applications.

[29]  H. Akagi,et al.  Design and performance of a passive EMI filter for use with a voltage-source PWM inverter having sinusoidal output voltage and zero common-mode voltage , 2004, IEEE Transactions on Power Electronics.

[30]  Somboon Sangwongwanich,et al.  Exact common-mode and differential-mode equivalent circuits of inverters in motor drive systems taking into account input rectifiers , 2011, 2011 IEEE Ninth International Conference on Power Electronics and Drive Systems.

[31]  Hirofumi Akagi,et al.  An active circuit for cancellation of common-mode voltage generated by a PWM inverter , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.