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In this work, a new elevator system created by a linear switched reluctance motor is presented. Unlike conventional linear motors, the proposed linear motor has more than one translator. Each phase in a translator generates a pulsing force; hence, the total generated force has noticeable ripple making it difficult to soft motion. In order to solve this problem, similar phases in different translators have been located in positions with specified distances together. As a result, similar force pulses would be shifted so that they can compensate together. An appropriate control strategy has been designed for the system, which can control the current, force, speed, and position simultaneously. A conventional proportional–integral controller and an adaptive fuzzy controller have been used to control the speed. In order to have a precise study, a prototype elevator system along with its control unit has been made and the obtained results have been compared with the simulation results. These results confirm that the proposed structure can significantly produce force and speed ripples. [ABSTRACT FROM AUTHOR]

A new adaptive control strategy for a double‐sided linear switched reluctance motor is proposed in this work. Switched reluctance motors inherently have non‐linear dynamics that complicates their analysis and control. The Takagi–Sugeno fuzzy logic system has been used in this work to achieve an appropriate adaptive control system for the proposed linear motor. The fuzzy system has been heightened by non‐linear rule consequences and a time‐varying parameter. Updated laws have been designed to refresh the amount of the parameter consequently the suggested control system shows a stable performance in control of switched reluctance motors. The proposed control strategy is independent of the uncertainties of the motor dynamics and has an acceptable adaptability. This control method along with a conventional fuzzy logic based system have been studied on the proposed linear switched reluctance motor and their performances were compared in different performance conditions. An appropriate evaluation method has been used to compare the obtained results. The efficiency of the proposed method in different velocity commands has been examined and confirmed using appropriate simulation and experimental results. [ABSTRACT FROM AUTHOR]

The distance protection of multi‐terminal transmission lines need to be redesigned due to possible changes in the backup protection emanating from probable infeed currents produced from tapped transmission lines. Furthermore, high‐resistance fault is another factor that relay become under‐reach and cannot correctly identify the fault. In this study, an algorithm is presented based on synchrophasors. In this method, voltage and current signals of buses will be sent to system protection centre (SPC) and in SPC an algorithm based on active power calculation in buses is provided that is able to eliminate the effects of both mentioned factors. In this method, measurement or relay in tapped transmission line location are not required. The study includes analytical analysis and modelling and in modelling results a variety of faults with different fault resistances is considered. Two power systems including teed‐feeder system and IEEE 14‐bus power system are considered. The results show that in both power systems, and different types of faults, backup distance protection is improved. Simulations are conducted by Electro‐Magnetic Transient Program works. [ABSTRACT FROM AUTHOR]

In this study, the effects of the delta-hexagonal phase shifting transformers (PSTs) on the operation of distance relays and their trip boundaries are investigated under different fault resistances and locations. Existence of fault resistance in phase-to-ground faults creates an unreliable operation of distance relays. Trip boundaries are used to determine the fault resistance effects on the impedance calculated by the relay. Moreover, PSTs are used to control the power flow in transmission lines. Finally, a feasible method for eliminating the PSTs detrimental effects on the operation of the distance relays is presented. This method, which uses the voltage difference between the PST terminals, is getting prevalent in modifying the operation of the distance relays even under the high resistance faults. Phasor measurement units (PMUs) are used to calculate this voltage as PMU signals and a remote signal system is used to transmit them to the system protection centre. All the simulations are conducted with Electro-Magnetic Transient Program. [ABSTRACT FROM AUTHOR]