NASHRIYYAH -I MUHANDISI -I BARQ VA MUHANDISI -I KAMPYUTAR -I IRAN, A- MUHANDISI -I BARQ
Year:2020 | Volume:18 | Issue:2|Papers Count:8

Gas-fueled power plants are considerably effective in power system operation during peak hours due to their high up and down ramping rates. By increasing the penetration of gas-fueled power plants in power systems and development of new technologies, such as power-to-gas (ptg) units, coordinated scheduling of both electricity and natural gas (NG) networks has attracted systems researchers’ attention. The NG volume generated by ptg units are stored in storages to directly supply the NG demands, or to sell in NG markets. If necessary, the stored NG volumes are reconverted into electricity which may be a suitable replacement for batteries and storages in electricity network in long term. In this paper, a mixed integer linear programming (MILP) model is proposed for stochastic coordinated scheduling of electricity and NG networks with ptg units, considering uncertainties of charging and discharging available capacities of vehicle to grid (v2g) stations. A test network integrating modified 24-bus IEEE electricity network and Belgium gas network including nine power stations (three of them are gas-fueled), three v2g stations, and three ptg stations is studied to evaluate the effectiveness of the proposed model. Simulation results demonstrate the effectiveness of ptg units in handling the uncertainties of v2g stations charging and discharging. Besides, the effectiveness of coordinated scheduling of both electricity and NG networks in comparison with independent scheduling of both networks is demonstrated.

One of the main tests of power circuit breaker is to evaluate their breaking capability. Direct test requires a high power source capacity but using the synthetic method and supplying current and voltage from two separated sources, allows to significant power reduction. This paper presents the design, development and fabrication of a synthetic circuit for testing vacuum circuit breaker using distribution network as current circuit. The development and construction of this equipment has made possible to perform short circuit breaking test on VCB according to international standards. Laboratory measurements show good conformity between design and fabrication.

Today, optimal operation and expansion planning have gained great attention in electricity industry optimizations and coordination of electricity and gas networks is one of the main goals in this procedure. In this study, decentralized operation of electricity and gas networks is modeled on a real-world case study in Khorasan province of Iran. This modeling is from the perspective of two independent operators who seek to minimize the operation cost of their subordinating network, considering technical constraints. In this way, the amount of gas consumption in gas and electricity networks is considered as a common variable and it is compared using different methods as ADMM, ATC and centralized. Moreover, operating cost is compared in all three different methods. Finally, scenarios of increased load and second fuel have also been investigated using the obtained model.

In this paper, a segmental SRM and its performance optimization via making some changes on its rotor is investigated. These changes not only reduce the torque ripple, but also increase the efficiency of the motor. Motor has two types of poles on its stator: main and auxiliary. The auxiliary poles make the flux path shorter and eliminate flux inversion on stator. Different types of notches on rotor structure are examined and the best one is chosen. For simulations, finite element method is utilized.

As technology nodes shrink below 90 nm, high static power consumption has become one of the biggest problems of CMOS based circuits due to the exponential leakage current of transistors. Spintronic devices such as magnetic tunnel junction (MTJ) due to their fascinating features such as low static power consumption, non-volatility, high endurance, compatibility with CMOS transistors and high-density fabrication are one of the promising candidate for designing hybrid MTJ/CMOS circuits and overcoming high static power consumption of CMOS based circuits. In this paper, a fully nonvolatile and low power hybrid MTJ/CMOS full-adder circuit for Realization of Process in Memory is proposed. The simulation results show that all the proposed circuit is at least 50% faster than all previous counterparts, the power output delay is 39% lower than the previous design, and does not impose high hardware overhead.

With the increasing of sensitive loads such as data centers, the use of DC microgrids has increased. Line to ground fault is the most common type of fault in this type of microgrid, which causes various damages to the DC microgrid. One of the most important challenges in operating a DC microgrid is the lack of effective protection against this faults type. In this paper, by using local measurements such as voltage and current at the beginning of each line, the instantaneous power changes in them are computed and a new protection scheme that is not based on any communication line is presented. The proposed protection scheme has good accuracy and speed of operation and is able to detect line-to-ground faults in DC microgrids with high-speed. The accuracy and precision of the protection scheme has been tested under different conditions.

In this paper, design and simulation of a new micro-displacement sensor based on photonic crystal fixed and movable segments is presented. It has been shown that using negative refraction photonic crystal in the fixed segment, the transmitted power is concentrated on the entrance of the movable segment, and the sensor specifications are improved. Based on the FDTD simulation results, the sensitivity, the operational displacement range and the regression coefficient of the proposed sensor are 1. 1 (a-1), 0. 35a and 0. 99848, respectively. The simulation results show that the proposed sensor has a good performance and could well be used in micro-displacement measuring systems.

In this paper, a biosensor based on a photonic crystal is designed. This sensor has two adjacent circular nano-rings that allow coupling between the waveguides and the nano-ring resonator. A number of dielectric rods have been used to design the sensor, which are located in the water environment. Circular ring resonators have also been used between the input and output waveguides. Also, in order to increase the optical restriction and improve the coupling performance of waveguides and nano-ring resonator, the input and output paths have been used closed end. In the proposed structure, which has a small dimension, the sensing rod is selected so that is has a high quality factor. The simulation results show that the designed biosensor has a high quality factor and by attaching the biomolecule to it, the displacement of the resonant wavelength is well formed. Another feature of the proposed structure is that all dielectric rods have the same radius, which makes it easier to construct the sensor.