Research of hybrid active power filter based on FBD method detection
To fast and effectively detect harmonic current of power system, FBD method is proposed. Compared with method which is based on instantaneous reactive power, FBD method has no complex transformation and transformation, it can be used to detect harmonic current for single-phase, three-phase three-wire and three-phase four-wire system. But FBD method needs a low-pass filter to extract the DC current, it causes delay and phase-shifting problems, to solve these problems, this paper presents a real-time sliding window to extract the DC current instead of low-pass filter. At the same time, shows the principle of hybrid active power filter, and corresponding mathematical model is established. Finally, take a new composite control strategy. Simulation results show correctness of the detection and effectiveness of the new composite control strategy.
DEFINITION AND COMPENSATION OF GENERALIZED INSTANTANEOUS REACTIVE CURRENT AND REACTIVE POWER IN abc COORDINATES
A new definition method for generalized instantaneous reactive current and reactive power of three-circuits in abc coordinates is presented and the detection and compensation method for generalized instantaneous reactive current is proposed. The results of simulation and research demonstrate that any additional hardware is not needed for the detection of the generalized instantaneous reactive current. For abrupt change of current the accurate detection of generalized instantaneous reactive current can be implemented in one power frequency period by the proposed method, meanwhile, the transmission loss is minimal and the distortion factor of the voltage is reduced to the minimum.
Eimeria odocoilei n. sp. from the mule deer Odocoileus h. hemionus in Washington.
SYNOPSIS. Eimeria odocoilei n. sp. is described from feces of a mule deer Odocoileus h. hemionus in Washington. Its oocysts are 26 to 28 by 22 to 26 μ. It is the second species of Eimeria described from this host.