Design and implementation of a linear motor for multi-car elevators

The multicar elevator system (MCE) is a revolutionary new technology for highrise buildings, promising outstanding economic benefits, but also requiring new technology for propulsion, safety, and control. In this thesis, new components for linear motor–driven multi-car elevators have been analysed and experimented successfully. It is shown that linear motors with optimized design and a new presented safety and control system can be considered as core components of a new generation elevator systems. The obtained results concern the development of a safety system integrated into the propulsion system, the design of a linear motor optimized for the multi-car elevator task, and the motion control system that is expected to be usable for extra high-rise buildings

Linear motor for multi-car elevators, design and position measurement

Multi-car elevator is an emerging technology consisting of two or more elevator cars moving independently in an elevator hoistway, which has become more appealing as building heights increase. In this paper, the design and drive methodologies for a linear motor driven multi-car elevator system with independently moving cars is introduced together with experimental results. Additionally, a safety method developed for the linear motor elevator and the conditions necessary for its proper operation are discussed. The new results introduced in this paper are in the areas of the design method of the linear motor for multi-car elevator system, and the preliminary results for the position measurement system

Design and implementation of a linear motor for multi-car elevators

The multi-car elevator system is a revolutionary new technology for high-rise buildings, promising outstanding economic benefits, but also requiring new technology for propulsion, safety and control. In this paper we report on experimental results with new components for linear motor driven multi-car elevators. We show that linear synchronous motors with optimized design and with our new safety and control system can be considered as core components of a new generation of elevator systems. The main new results concern the development of a safety system integrated into the propulsion system, the design methodology of a linear motor optimized for the multi-car elevator task, and the motion control system that is expected to be usable for extra high-rise buildings

Modeling of air core permanent-magnet linear motors with a simplified nonlinear magnetic analysis

This paper presents a new analysis method for air core permanent magnet synchronous linear motor design optimization problems with a large search space. The aim is to reduce the total computational time by replacing most of the finite element analysis (FEA) steps with an analytical model of the motor consisting of nonlinear equivalent magnetic circuit and flux density distribution models. A small number of FEA steps are used to determine some parameters of the analytical model. The result of the proposed method is compared with results of both a pure FEA design and experiments on a real motor. The proposed method has similar performance to FEA, although computationally it is at least two orders of magnitude faster

Linear Motor for Multi-Car Elevators: Design and Position Measurement

Abstract-Multi-car elevator is an emerging technology consisting of two or more elevator cars moving independently in an elevator hoistway, which has become more appealing as building heights increase. In this paper, the design and drive methodologies for a linear motor driven multi-car elevator system with independently moving cars is introduced together with experimental results. Additionally, a safety method developed for the linear motor elevator and the conditions necessary for its proper operation are discussed. The new results introduced in this paper are in the areas of the design method of the linear motor for multi-car elevator system, and the preliminary results for the position measurement system

Linear motor coils as brake actuators for multi-car elevators

Multi-car elevator systems have two or more eleva-tor cars moving independently in the same hoist-way [1]. They promise extraordinary improvements in the space utilisation for large buildings. At the same time, there are still many problems to be solved before multi-car elevators can be oered as a viable alternative for current elevator systems. One of these open problems is how to prevent reliably and eco-nomically the collision of the independently moving elevators, even in the case of failures in the power supply or the control system. In our research, we have developed a safety sys-tem for multicar elevators, with the unique feature of using the edge surface of the linear motor coil as the actuator solenoid of the brakes. In the following, we report on theoretical analysis and scale-model test results, showing the feasibility of this approach

Linear motor coils as brake actuators for multi-car elevators

Multi-car elevator systems have two or more eleva-tor cars moving independently in the same hoist-way [1]. They promise extraordinary improvements in the space utilisation for large buildings. At the same time, there are still many problems to be solved before multi-car elevators can be oered as a viable alternative for current elevator systems. One of these open problems is how to prevent reliably and eco-nomically the collision of the independently moving elevators, even in the case of failures in the power supply or the control system. In our research, we have developed a safety sys-tem for multicar elevators, with the unique feature of using the edge surface of the linear motor coil as the actuator solenoid of the brakes. In the following, we report on theoretical analysis and scale-model test results, showing the feasibility of this approach

Pregnancy and its outcomes in hemodialysis patients in Turkey

Background/aim: This study aimed to investigate pregnancy frequency and evaluate the factors affecting live births in hemodialysis (HD) patients. Materials and methods: Female HD patients whose pregnancy was retrospectively reported between January 1, 2014, and December 31, 2019. The duration of HD, primary disease, and the information on whether the pregnancy resulted in abortion, stillbirth, or live birth, whether the HD duration was prolonged after diagnosing the pregnancy and whether it accompanied preeclampsia were recorded. Results: In this study, we reached 9038 HD female patients' data in the study. A total of 235 pregnancies were detected in 145 patients. The mean age was 35.42 (35 +/- 7.4) years. The mean age at first gestation was 30.8 +/- 6.5 years. The average birth week was 32 (28 -36) weeks. A total of 53.8% (no = 78) of the patients had live birth, 51.7% (no = 70) had at least one abortion in the first 20 weeks, and 13.1% (no = 19) had at least one stillbirth after 20 weeks. The rate of patients' increased numbers of dialysis sessions during pregnancy was 71.7%. The abortion rate was 22.4% in those with increased HD sessions, whereas 79.3% in those not increased HD sessions (p < 0.001). Live birth frequency was 67.2% in the increased HD sessions group and 3.4% in those who did not differ in HD sessions (p < 0.001). Conclusion: For the first time, we reported pregnancy outcomes in HD female patients, covering all regions of Turkey. It has been observed that; increasing the number of HD sessions in dialysis patients will decrease fetal and maternal complications and increase live birth rates

Pregnancy and its outcomes in hemodialysis patients in Turkey

Background/aim: This study aimed to investigate pregnancy frequency and evaluate the factors affecting live births in hemodialysis (HD) patients. Materials and methods: Female HD patients whose pregnancy was retrospectively reported between January 1, 2014, and December 31, 2019. The duration of HD, primary disease, and the information on whether the pregnancy resulted in abortion, stillbirth, or live birth, whether the HD duration was prolonged after diagnosing the pregnancy and whether it accompanied preeclampsia were recorded. Results: In this study, we reached 9038 HD female patients' data in the study. A total of 235 pregnancies were detected in 145 patients. The mean age was 35.42 (35 +/- 7.4) years. The mean age at first gestation was 30.8 +/- 6.5 years. The average birth week was 32 (28 -36) weeks. A total of 53.8% (no = 78) of the patients had live birth, 51.7% (no = 70) had at least one abortion in the first 20 weeks, and 13.1% (no = 19) had at least one stillbirth after 20 weeks. The rate of patients' increased numbers of dialysis sessions during pregnancy was 71.7%. The abortion rate was 22.4% in those with increased HD sessions, whereas 79.3% in those not increased HD sessions (p < 0.001). Live birth frequency was 67.2% in the increased HD sessions group and 3.4% in those who did not differ in HD sessions (p < 0.001). Conclusion: For the first time, we reported pregnancy outcomes in HD female patients, covering all regions of Turkey. It has been observed that; increasing the number of HD sessions in dialysis patients will decrease fetal and maternal complications and increase live birth rates