Fast Voltage Stabilization Control of Split DC Bus Midpoint in 3P4W Shunt APFs

A midpoint voltage balancer (MVB) based on dual-switching-leg is proposed in this paper. The MVB provides fast voltage stabilization of the midpoint in three-phase four-wire (3P4W) shunt active power filters (APFs). Interleaved control is adopted in the MVB to prevent high-frequency current circulation in split capacitors, and to facilitate an accurate neutral current tracking. All switches of the MVB operate in zero-voltage switching (ZVS) mode when the neutral current is smaller than the nominal phase current of the APF. MATLAB simulation is carried out to verify the effectiveness of the MVB. A 20 kVA prototype has been built, and experimental results show that the voltage ripple of the midpoint is maintained within 1.5% of the total dc bus voltage even under severe neutral current transient.

[1]  Fei Wang,et al.  Grid-Interfacing Converter Systems With Enhanced Voltage Quality for Microgrid Application—Concept and Implementation , 2011, IEEE Transactions on Power Electronics.

[2]  X. Ruan,et al.  Optimized Design of the Neutral Inductor and Filter Inductors in Three-Phase Four-Wire Inverter With Split DC-Link Capacitors , 2019, IEEE Transactions on Power Electronics.

[3]  Solleti Hanuman Sairam.  A Voltage Regulator for Power Quality Improvement in Low-Voltage Distribution Grids , 2018 .

[4]  V. Khadkikar,et al.  Enhancing Electric Power Quality Using UPQC: A Comprehensive Overview , 2012, IEEE Transactions on Power Electronics.

[5]  Mahesh K. Mishra,et al.  A Grid-Connected Dual Voltage Source Inverter With Power Quality Improvement Features , 2015, IEEE Transactions on Sustainable Energy.

[6]  Bin Wu,et al.  Control strategies of three-phase distributed generation inverters for grid unbalanced voltage compensation , 2015 .

[7]  Mahesh Kumar Mishra,et al.  DC Capacitor Voltage Equalization in Neutral Clamped Inverters for DSTATCOM Application , 2010, IEEE Transactions on Industrial Electronics.

[8]  Stefano Bifaretti,et al.  Modulation With Sinusoidal Third-Harmonic Injection for Active Split DC-Bus Four-Leg Inverters , 2016, IEEE Transactions on Power Electronics.

[9]  Lieven Vandevelde,et al.  Comparison of three-phase four-wire converters for distributed generation , 2010, 45th International Universities Power Engineering Conference UPEC2010.

[10]  Wuhua Li,et al.  Review of Nonisolated High-Step-Up DC/DC Converters in Photovoltaic Grid-Connected Applications , 2011, IEEE Transactions on Industrial Electronics.

[11]  A. Joshi,et al.  Control Schemes for Equalization of Capacitor Voltages in a Neutral Clamped Shunt Compensator , 2002, IEEE Power Engineering Review.

[12]  Karl Koch,et al.  Method for DC-link voltage balancing for a grid-connected inverter in case of asymmetric operation , 2017, 2017 19th European Conference on Power Electronics and Applications (EPE'17 ECCE Europe).

[13]  Huan Yang,et al.  Topologies and control strategies of multi-functional grid-connected inverters for power quality enhancement: A comprehensive review , 2013 .

[14]  Huai Wang,et al.  Lifetime Estimation of DC-Link Capacitors in Adjustable Speed Drives Under Grid Voltage Unbalances , 2019, IEEE Transactions on Power Electronics.

[15]  Jin-Woo Jung,et al.  A Three-Phase Four-Wire Inverter Control Technique for a Single Distributed Generation Unit in Island Mode , 2008, IEEE Transactions on Power Electronics.

[16]  E. A. Lomonova,et al.  Sequence-Decoupled Resonant Control of Three-Phase Grid-Interfacing Inverter for Local Voltage Support Under Unbalanced Load , 2018, 2018 20th European Conference on Power Electronics and Applications (EPE'18 ECCE Europe).

[17]  Kamal Al-Haddad,et al.  A review of active filters for power quality improvement , 1999, IEEE Trans. Ind. Electron..

[18]  Mauricio Aredes,et al.  Three-phase four-wire shunt active filter control strategies , 1997 .

[19]  Xinbo Ruan,et al.  Neutral Point Voltage Ripple Suppression for a Three-Phase Four-Wire Inverter With an Independently Controlled Neutral Module , 2017, IEEE Transactions on Industrial Electronics.