Takeki Ando

Development of a high-speed elevator controlled by current source inverter system with sinusoidal input and output

An inverter elevator (2.5-4 m/s rated speed) which is controlled by a current source inverter system with sinusoidal input and output is developed. In comparison with a conventional DC elevator controlled by the thyristor Leonard system, it has the following features: (1) a reduction of higher harmonic currents to less than 5%; (2) more than a 30% reduction of power source capacity; (3) more than a 10% reduction of energy consumption, and (4) a 40% reduction of traction machine weight. The sinusoidal pulsewidth modulation control of the converter and inverter, performed by one-chip microprocessors, is described along with a detection and protection system for abnormal overvoltage. A general description of the elevators performance is given. >

A New Speed Control System for DC Motors Using GTO Converter and its Application to Elevators

A dc motor control system using a new GTO converter, is developed for an intermediate-speed elevator (2.5-m/s rated speed and 1000-kg load). Its features include 1) a main circuit control system composed of pulsewidth and phase controls, 2) a circuit to suppress the overvoltage which occurs when the GTO is turned off, 3) direct digital control which is composed of an acceleration control to compensate for lag time in the field current response and a self-correcting function to compensate for landing error. Application of the control system provided a higher power factor and smaller power consumption than a conventional control system.

Attitude control system of a super-high speed elevator car based on magnetic guides

This paper describes a new attitude control system of a super-high speed elevator car based on magnetic guides. Using a conventional roller guide system for attitude control of a super-high speed elevator car (810 m/min class) will result in serious horizontal vibration caused by the winding guide rails which are installed in the hoist way to guide the elevator car. The new control system proposed realizes acceleration control to suppress the car vibration at high speed running. The system is based on a magnetic guide controlling the attractive power between the guide rails and electro-magnets which are fixed to the elevator car frame. The effectiveness of the proposed method is confirmed by computer simulation and experimental results obtained using full scale equivalent testing equipment.<<ETX>>

A New Speed-Control System for DC Motors and its Application to Elevators

A circuit with a unidirectional armature current and bidirectional field current was used in order to realize a high-reliability speed-control system for dc motors by simplifying the armature circuit construction in comparison with conventional Thyristor-Leonard speed-control systems. In making the new circuit feasible, we developed a system in which either armature current or field current is fixed and the other varies depending on the magnitude of the torque command; a high-reliability magnetically controlled three-phase thyristor amplifier; and minor feedback loops provided with a field current control circuit and armature current control circuit. By using these techniques, we developed a dc motor control system that features higher reliability and smaller power consumption than conventional control systems. The new system was applied to elevator control with good results.