Analytic techniques for predicting onset of voltage collapse in power systems often rely upon identification of a saddle node bifurcation. While many authors acknowledge that the separation between voltage phenomena and phase angle phenomena is far from absolute, most recent works have viewed voltage variation as the more significant problem. The goal of the work presented here is to shift focu...

A new model of Interphase Power Controller (IPC) for controlling active power is introduced in this paper. In this model, which is called VSC-based IPC, the voltage source converter (VSC) does the function of the phase shifting transformer (PST) in IPC. This new structure not only has the features of IPC, but also controls the output power effectively when the input power is changed by alternat...

The effect of line impedance compensation mode of series inverter along with the voltage regulation mode of shunt inverter of UPFC is investigated for transient stability improvement of Single Machine Infinite Bus System. Four control modes like perpendicular voltage or phase angle control etc have also been discussed. The effect of line impedance mode on critical clearing time with a three pha...

Voltage sags are normally described by magnitude variation and duration. In addition to these quantities, sags are also characterized by unbalance (asymmetry), nonsinusoidal waveshapes, and phase angle shift (phase jump). These factors are important for determining the behavior of ac motor drives during sags. Voltage unbalance and phase angle shifts cause large unbalanced source currents to, ex...

A three-phase space-vector based PWM rectifier with power factor control has been proposed in this paper. The three-phase phase locked loop (PLL) is designed to detect the phase angle of utility voltage, which is used to create three-phase reference currents. The proposed scheme is simple and practical to be implemented on a fixed-point digital signal process based controller. It also does not ...

Enhancing compensating capability is essential in a voltage-sag compensator. It involves two main aspects, first, sag detection technique and second, voltage sag compensator. Many detection techniques have been introduced to measure and to detect voltage sag, such as RMSValue Evaluation and Peak-Value Evaluation. Unfortunately, most of the techniques require a delay for sag to be detected then ...

This paper deals with simulation of multilevel inverter based DVR. The DVR circuit produces high quality voltage since it uses a nine level inverter. This DVR gives better solution to the voltage sag problem by injecting a voltage with reduced harmonics. DVR controls the voltage applied to the load by injecting voltage of proper amplitude and phase angle. Thus DVR is responsible for restoring q...

This paper discusses a Static Synchronous Series Compensator which is constructed with a 48-pulse inverter. Extensive simulation studies are carried out to verify the proper operation of the mentioned Flexible AC Transmission Systems (FACTS) device. In MATLAB simulation environment the designed device is connected to a power system that is comprised of three phase power source, transmission lin...