TY - GEN

T1 - Solving the ill-conditioned polynomial for the optimal PWM

AU - Huang, Han

AU - Hu, Shiyan

AU - Czarkowski, Dariusz

PY - 2004

Y1 - 2004

N2 - The Selective Harmonic Elimination (SHE) Pulse-Width Modulation (PWM) inverter eliminates low-order harmonics by optimizing the switching angles distribution and can generate high quality output waveforms. The switching angles can be obtained through solving a set of transcendental equations with the coefficients from the inverter output waveform Fourier series. The conventional algorithm for resolving SHE-PWM problem is Newton-Raphson algorithm. The main shortcoming in applying Newton-type algorithms is that the results deeply depend on the selection of initial values. In this paper, a new algorithm is proposed to solve the nonlinear system in the SHE-PWM problem without suffering from above shortcoming. The algorithm first transforms the nonlinear equations into a poly-nomial problem. An important observation is that the original system and thus the polynomial are highly ill-conditioned, so the conventional algorithms can seldom accurately computing roots for the polynomial. A novel Eigensolve algorithm is introduced since the algorithm is especially good for solving the highly ill-conditioned polynomial. The simulation results indicate the robustness of the method.

AB - The Selective Harmonic Elimination (SHE) Pulse-Width Modulation (PWM) inverter eliminates low-order harmonics by optimizing the switching angles distribution and can generate high quality output waveforms. The switching angles can be obtained through solving a set of transcendental equations with the coefficients from the inverter output waveform Fourier series. The conventional algorithm for resolving SHE-PWM problem is Newton-Raphson algorithm. The main shortcoming in applying Newton-type algorithms is that the results deeply depend on the selection of initial values. In this paper, a new algorithm is proposed to solve the nonlinear system in the SHE-PWM problem without suffering from above shortcoming. The algorithm first transforms the nonlinear equations into a poly-nomial problem. An important observation is that the original system and thus the polynomial are highly ill-conditioned, so the conventional algorithms can seldom accurately computing roots for the polynomial. A novel Eigensolve algorithm is introduced since the algorithm is especially good for solving the highly ill-conditioned polynomial. The simulation results indicate the robustness of the method.

KW - Harmonic elimination

KW - Ill-conditioned polynomial

KW - Pulse-width modulation

UR - http://www.scopus.com/inward/record.url?scp=19644388391&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=19644388391&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:19644388391

SN - 0780387465

SN - 9780780387461

T3 - 2004 11th International Conference on Harmonics and Quality of Power

SP - 555

EP - 558

BT - 2004 11th International Conference on Harmonics and Quality of Power

T2 - 2004 11th International Conference on Harmonics and Quality of Power

Y2 - 12 September 2004 through 15 September 2004

ER -