Output impedance

About: Output impedance is a research topic. Over the lifetime, 11185 publications have been published within this topic receiving 134949 citations.

Adjustable impedance matching network

Abstract: An impedance matching network includes a first terminal, a second terminal, and a reference potential terminal. The impedance matching network further includes a first shunt branch between the first terminal and the reference potential terminal, the first shunt branch including a capacitive element. The impedance matching network also includes a second shunt branch between the second terminal and the reference potential terminal, the second shunt branch including an inductive element. Furthermore, the impedance matching network includes a transmission line transformer with a first inductor path and a second inductor path, wherein the first inductor path connects the first terminal and the second terminal. An alternative impedance matching network includes a transformer and an adaptive matching network. The transformer is configured to transform an impedance connected to a first port so that a corresponding transformed impedance lies within a confined impedance region in a complex impedance plane.

Insensitive current/voltage-mode filters using FTFNs

Abstract: A new configuration for realising insensitive current/voltage-mode filters using two four-terminal floating nullors (FTFNs) is presented. It can provide the curren/voltage-mode filters with reduced sensitivities. Moreover, the current-mode filters can have high output impedance and only grounded capacitors. The proposed universal voltage-mode filter with dual outputs can realise lowpass, bandpass, highpass, notch and allpass filtering functions. Simulation results are given to verify the theoretical analysis.

Low-Frequency Input Impedance Modeling of Boost Single-Phase PFC Converters

Abstract: Input impedance models of boost single-phase power factor correction converters suitable for predicting small-signal input characteristics below the line fundamental frequency are presented in this paper. Existing low-frequency input impedance models based on double averaging predicts input current responses to perturbations in the amplitude of the input voltage. It is shown in this paper that such impedance models do not conform to the standard definition of impedance, and, hence, cannot be used in conjunction with the source output impedance to study system interactions based on the Nyquist stability criterion, as traditionally done in dc power systems. A new input impedance model that overcomes this problem is developed by using the method of harmonic balance. The new model conforms to the standard definition of impedance and predicts input current responses to superimposed input harmonic voltages. Numerical simulation and experimental results are presented to validate the proposed model. Mathematical relationship between the two types of models are also presented.

Input Impedance Modeling and Analysis of Line-Commutated Rectifiers

Abstract: This paper presents the modeling and analysis of small-signal input impedance for line-commutated rectifiers. The recently developed impedance mapping method, which has been applied to single-phase rectifiers with sinusoidal line inputs, is generalized to single-phase rectifiers with distorted lines as well as three-phase rectifiers. The modeling method assumes known impedance of the circuit on the dc side of the rectifier bridge (including its output filter and the load), and determines the corresponding ac input impedance by using a current and voltage mapping function which describes the operation of the rectifier bridge in the frequency domain. In this approach, closed-form analytical expressions are derived for the ac input impedance as functions of the dc circuit impedance. The resulting models are intended for stability analysis and design of large ac power systems involving significant number of rectification loads, such as more-electric aircraft power systems and microgrids. Detailed derivation of the models is presented in this paper. Numerical simulation and experimental measurement results are also presented to validate the derived models.