A dynamic model for inertia energy stored generator with rectifier system
Due to diode elements, inertia energy stored generator with rectifier system possess the characteristic of nonlinearity, which cause great difficulty in analyzing systematic performance. In this paper, The inertia energy stored generator is modeled based on the fact that subtransient electric motive force (EMF) maintain constant during commutation process, and the uncontrollable rectifier system is also modeled based on state space averaging method. Both of which provide an effective model for systematic analysis.
Simple methods for detecting zero crossing
Affects of noise, harmonics, and multi-frequency signal make frequency and period measurements difficult for synchronizing control events. Various methods are presented to minimize errors in period and phase measurements. Both frequency and amplitude domain approaches are analyzed. Post detection processing allows greater accuracy. Static and dynamic hystereses as well as interpolation methods of zero-crossing detection are investigated.
Adaptive lowpass filters for zero-crossing detectors
Computationally efficient adaptive digital filters are introduced for 50/60 Hz line frequency signal processing in zero-crossing detectors in power converters. The purpose of the filter is to extract the fundamental sinusoidal signal from noise and impulsive disturbances so that the output is accurately in phase with the primary input signal. The proposed filters have fixed coefficients which are multiplied by adaptive parameters in order to adapt to the instantaneous line frequency. Only two adaptive parameters are needed in this method. Two linear-phase approaches are considered for the basis filters, one designed for good stopband attenuation and the other for computational simplicity.