DSP control method of single-phase inverters for UPS applications

This paper presents a new deadbeat control solution and a digital control strategy suited for high performance single-phase inverters capable to maintain very low THD of less than 1% in presence of unknown loads (linear or highly nonlinear). The method takes into account the digital model of the PWM inverter and derives a new set of gains for the voltage and current loops. The current loop gain obtained by this approach is shown to be higher than previously known and this leads to a better disturbance rejection and faster dynamic response. The control strategy was implemented on a 16-bit fixed-point DSP controller (ADMC401) and tested on a 5-kVA IGBT-based inverter switching at 20 kHz.

[1]  Paolo Mattavelli,et al.  Synchronous-frame harmonic control for high-performance AC power supplies , 2001 .

[2]  Robert D. Lorenz,et al.  Control topology options for single-phase UPS inverters , 1996, Proceedings of International Conference on Power Electronics, Drives and Energy Systems for Industrial Growth.

[3]  R. G. Hoft,et al.  Controlled PWM Inverter with Parameter Estimation Using Only Voltage Sensor , 1986 .

[4]  S. D. Finn.  A high performance inverter technology, architecture and applications , 1993, Proceedings Eighth Annual Applied Power Electronics Conference and Exposition,.

[5]  K. Mauch,et al.  Parallel operation of single phase inverter modules with no control interconnections , 1997, Proceedings of APEC 97 - Applied Power Electronics Conference.

[6]  Robert D. Lorenz,et al.  A high performance sine wave inverter controller with capacitor current feedback and "back-EMF" decoupling , 1995, Proceedings of PESC '95 - Power Electronics Specialist Conference.

[7]  Atsuo Kawamura,et al.  Waveform compensation of PWM inverter with cyclic fluctuating loads , 1988 .

[8]  Karl Johan Åström,et al.  Computer-Controlled Systems: Theory and Design , 1984 .

[9]  Ying-Yu Tzou,et al.  DSP-based fully digital control of a PWM DC-AC converter for AC voltage regulation , 1995, Proceedings of PESC '95 - Power Electronics Specialist Conference.

[10]  Tore Undeland,et al.  Power Electronics: Converters, Applications and Design , 1989 .

[11]  P. Enjeti,et al.  DSP control of high power UPS systems feeding nonlinear loads , 1995, Proceedings of 1995 American Control Conference - ACC'95.

[12]  Ying-Yu Tzou,et al.  DSP-based multiple-loop control strategy for single-phase inverters used in AC power sources , 1997, PESC97. Record 28th Annual IEEE Power Electronics Specialists Conference. Formerly Power Conditioning Specialists Conference 1970-71. Power Processing and Electronic Specialists Conference 1972.

[13]  T. Inoue,et al.  Practical repetitive control system design , 1990, 29th IEEE Conference on Decision and Control.

[14]  Ying-Yu Tzou,et al.  High-performance programmable AC power source with low harmonic distortion using DSP-based repetitive control technique , 1997 .

[15]  J.W. Dixon,et al.  A simple frequency-independent method for calculating the reactive and harmonic current in a nonlinear load , 1996, IEEE Trans. Ind. Electron..