Current Injection Model Research Articles

Development of Stochastic Aggregate Harmonic Load Model Based on Field Measurements

The stochastic simulation approach in analyzing harmonic propagation in the distribution network requires an adequate stochastic/probabilistic aggregate harmonic load model. The interaction of individual linear and harmonic loads that form aggregate load characteristic harmonic current spectra is usually very complex and, therefore, it is difficult to establish a model based on theoretical analysis. This paper presents a methodology in developing a stochastic/probabilistic aggregate harmonic load model based on field measurements. The model is a current injection model characterized by means and variances associated with net harmonic current spectra produced by aggregate harmonic loads, and a range of aggregate harmonic load power participation (fraction) into total demand, suitable for application in stochastic harmonic propagation studies in distribution networks

Power flow control and solutions with multiple and multi-type FACTS devices

In this paper, a new generalized current injection model of the modified power system using Newton–Raphson power flow algorithm has been proposed for desired power transfer with Flexible AC Transmission Systems (FACTS) devices. So that the FACTS devices can be incorporated in the proposed algorithm and, therefore, whole system with these devices can be easily converted to power injection models without change of original admittance and the Jacobian matrices. Power flow algorithm has been modeled in such a way that it can easily be extended to multiple and multi-type FACTS devices by adding a new Jacobian corresponding to that new device only. Power flow algorithm with the presence of Thyristor Controlled Series Compensators (TCSC), Unified Power Flow Controller (UPFC), and Generalized Unified Power Flow Controller (GUPFC) has been formulated and solved. To demonstrate the performance of the proposed algorithm for multiple and multi-type FACTS devices, different case studies of IEEE 30-bus system has been considered and the results are tabulated. The proposed algorithm is independent of the size of the system and initial starting conditions of the FACTS devices.

A Newton-Type Current Injection Model of UPFC for Studying Low-Frequency Oscillations

This paper presents a Newton-type current injection model of the unified power flow controller (UPFC) for studying the effect of the UPFC on the low-frequency oscillations. Since the proposed model is a Newton-type one, it is conceptually simple and gives fast convergence characteristics. The model is applied to an inter-area power oscillation damping regulator design of a sample two-area power system. The damping achievable by the UPFC equipped with damping regulator is investigated in both frequency and time domains using the proposed model. The case study results in this paper show that the proposed model is efficient for studying the effects of the UPFC on the inter-area oscillations.

Distributed nature of quantum-well lasers

In this letter, we show that a quantum-well laser should be modeled as a distributed, rather than a lumped, device. Using a detailed model of current injection which analyzes electron and hole distribution in space as well as in energy, we demonstrate that the static and dynamic laser responses are not uniform along the growth axis.

Probabilistic Modeling of Power System Harmonics

A generalized procedure to obtain the probabilistic model of power system harmonic current injection and propagation is presented. The model takes into account random variations of both the operating modes as well as the configuration of nonlinear loads connected to a distribution feeder. The method is illustrated by an example of a bus having linear as well as nonlinear loads of different types. Potential applications of the model are also discussed.

Current injection in multiquantum well lasers

A model of current injection in a multiquantum well laser structure is proposed. A condition for uniform pumping of the wells is derived. For a given barrier height, uniform pumping can be achieved by increasing the ratio of the well-to-barrier thickness. The mechanism of current transport at thermal equilibrium for uniform pumping is by drift current in the barrier layers which equals the current injected from the external circuit.