Multi mode oscillation was observed in a 300 GHz fully CW gyrotron. It has been developed and installed in Research Center for Development of Far-Infrared Region, University of Fukui as a power source of a submillimeter wave material processing system. This gyrotron delivers 1.75 kW / CW at maximum. The radiation pattern is a Gaussian beam when the magnetic field strength Bc at the cavity is pr...

Pulse Width modulated based Series Compensator (PWMSC), a newly FACTS device, can modulate the impedance of a transmission line through the variation of the duty cycle of a train of pulses with fixed frequency, resulting in improvement of system performance. In this study, a current injection model of PWMSC is proposed and incorporated in the transmission system model. The purpose of the work r...

We have built a vertical seismometer that works based on the moiré technique. One grating is attached to the suspended mass and one to the frame of the instrument. The two gratings are in relative motion, and the resulting moiré pattern magnifies this motion. The intensity of a light beam passing through the moving moiré fringes changes with time, and a light detecting syst...

The power system network is becoming more complex nowadays so maintaining the stability of the power system is very difficult. So we have designed a 12-pulse based Static Synchronous Series Compensator (SSSC) which is operated with and without integration of Superconducting Magnetic Energy Storage (SMES) for enhancing the voltage stability and power oscillation damping in multi area system. Con...

In this paper, a real-time demodulation of real power oscillations in a three phase electric power system is proposed. It is shown how demodulated real power oscillations can be used to formulate a low order state space model that models power oscillations. The procedure is illustrated on the measurements obtained from three phase Resistor-Inductor-Capacitor (RLC) network where the power oscill...

This paper proposes a robust control framework for power system stabilizer to improve system dynamic performance based on model predictive control (MPC). The effectiveness of the proposed power system stabilizer is validated by a simple power system composed of a synchronous generator connected to an infinite bus through a transmission line. A comparison between power system responses at variet...

In this paper, a parallel AC/DC power system is investigated, and a nonlinear robust controller is proposed to improve transient stability of the power system and to damp out any prolonged oscillation after a fault is cleared. Lyapunov’s direct method is used to synthesize the control, and asymptotic stability of the closed loop system and improved dynamic performance are shown by both theoreti...

In this paper the application of a hierarchical fuzzy system (HFS) based on MPSS and SVC in multi-machine environment is studied. Also the effect of communication lines active power variance signal between two ∆PTie-line regions, as one of the inputs of hierarchical fuzzy multi-input PSS and SVC (HFMPSS & SVC), on the increase of low frequency oscillation damping is examined. In the MPSS, to ha...

Original scientific paper The indicators and methods of the probabilistic stability analysis of interconnected power grid’s low frequency oscillation are put forward in this paper, and the case study based on the real interconnected power grid is investigated. As the probabilistic distribution of various uncertain factors of power grid is known, the method of two-point-estimation is adopted to ...