This paper discusses the effect of load change on the Thevenin equivalent impedance of power systems. In this paper, the Thevenin equivalent impedance influenced by the derivative of active load with respect to reactive load (dP/dQ) is analyzed. The Thevenin equivalent impedance forms a closed curve in a complex plane and shrinks to one point when voltage collapses. The magnitude of the Theveni...

The limited usefulness of the maximum power transfer theorem in practice is argued. Inappropriately, the utility and value of the maximum power transfer theorem are often elevated to be religious icons of electrical engineering. While the theorem appears to be useful, often in real circuits the load impedance is not set equal to the complex conjugate of the equivalent impedance of the connectin...

QCM interactions with a discretely resonant load much greater in frequency than the quartz resonator’s shows negative frequency changes with increasing mass loading. However, a positive frequency increase of the coupled system occurs when the load resonant frequency is less than the quartz resonator’s. A brief review of the method by which a resonant load can be coupled into the electromechanic...

This paper analyzes the steady state performance of an isolated 3-phase self excited induction generator (SEIG) feeding balanced resistive load. The effects of load admittance and excitation capacitance on magnetizing reactance, frequency, terminal voltage, currents have been shown in this paper. The equivalent circuit of SEIG has been analyzed by loop impedance method to develop circuit equati...

In this paper, a novel approach based on the Thévenin tracing is presented to modified conventional impedance-based out-of-step (OOS) protection. In conventional approach, the OOS detection is done by measuring positive sequence impedance. However, the measured impedance may be change due to different factors such as capacitor bank switching and reactive power compensators that it can cause the...

Samples of Gd2O3-doped CeO2 (GDC) were fabricated by sintering of powder compacts. Impedance spectra were measured from 400 C to 675 C in air by electrochemical impedance spectroscopy (EIS). Above w500 C, high frequency arc was not semicircular but could be fitted with a constant phase element (CPE). Abovew625 C, high frequency arc could not be resolved due to a significant contribution from th...

With the introduction of distributed generators (DG), the traditional distribution system characterized by radical network becomes a multi-source one. Therefore the accuracy of the equivalent model of distributed generators directly affects the precision of fault location. To solve this problem, this paper proposed a fault location method based on complex correlation Thevenin equivalent and str...

Load characteristics are the main factor to affect voltage stability. In addition, load modeling reflecting the actual load characteristics has been a well—known difficult problem and unsolved so far, It is mainly due to the fact that the load composition, amount and characteristics are always changing. This paper introduces the slip into the equivalent impedance load model to analyze load char...