Otis Elevator Company

Prasanna Nagarajan

Shashank Krishnamurthy

Ismail Agirman

Edward D Piedra

Konda Reddy Chevva

Yang Wang

Daryl J Marvin

Amir Lotfi

David Ginsberg

Ronnie E Thebeau

HanJong Kim

Emmanuel Convard

Antoine Adrian Blanchard

Michael Peters

Camilo Cardona

Gregor Stricker

Hanjong Kim

Edward Piedra

An elevator system control system is provided and includes a sensor system configured to sense elevator car conditions, a safety system signaling element to generate a safety signal indicative of an incident and a control system configured to react to the safety system signal. When the control system receives the safety signal indicating that an incident has occurred that requires engagement of at least one of primary and secondary brakes, the control system controls a deceleration rate during the incident by operating the primary brake, determining whether the deceleration rate is within a target range and adjusting the deceleration rate based on signals from the sensor system.

Active braking for immediate stops

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of a plurality of phases of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to detection of an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

Emergency braking for a drive system

An illustrative elevator system includes an elevator car, a machine including a motor that provides a motive force for moving the elevator car along a travel path and a brake that resists movement of the elevator car, and a brake controller. The brake controller is configured to determine when the elevator car is within a selected range of at least one end of the travel path. The brake controller inhibits a delay in application of the brake when the elevator car is within the selected range and permits a delay in application of the brake when the elevator car is outside of the selected range.

Elevator machine brake delay control

A permanent magnet (PM) synchronous electric motor () includes a plurality of phases, and a plurality of motor drives () electrically connected to the PM synchronous electric motor. Each of the motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases. A controller () is operatively connected to each of the plurality of motor drives to selectively control the PM synchronous electric motor, and a rescue module () operatively connected to the controller, the rescue module being configured and disposed to determine a failure of one of the plurality of motor drives and control the PM synchronous electric motor in a reduced operation profile employing remaining ones of the plurality of motor drives.

Rescue control and method of operating an elevator system including a permanent magnet (PM) synchronous motor drive system

A system includes a converter operatively connected to an alternating current (AC) power source and a direct current (DC) bus, an inverter operatively connected to a motor and the DC bus, and a controller. The converter includes a first plurality of switching devices in selective communication with each phase of the AC power source and the DC bus. The inverter includes a second plurality of switching devices in selective communication with each phase of the motor and the DC bus. The controller is operable to command dropping of a brake through a passive delay circuit responsive to an emergency stop condition for a load driven by the motor and reduce a voltage on the DC bus by dropping at least one phase of the AC power source and/or using a dynamic braking resistor prior to the brake physically dropping.

A method () for controlling a multilevel regenerative drive () having a converter () and an inverter () is disclosed. The method () may include applying at least one of unipolar modulation and bipolar modulation to the converter (), and applying at least one of unipolar modulation and bipolar modulation to the inverter (). A control system () for a mechanical system () having a motor () is also disclosed. The control system () may comprise a converter () operatively connected to a power source (), and an inverter () operatively connected to the motor () of the mechanical system (). At least one controller may be in communication with the converter () and inverter (), and may be configured to apply at least one of unipolar modulation and bipolar modulation to each of the converter () and the inverter ().

PWM strategy for regenerative multilevel drive

An illustrative example method of maintaining an elevator drive includes determining whether a humidity condition near the elevator drive is outside a desired range. When the humidity condition is outside the desired range and the elevator drive is idle, reactive power is provided to at least one component of the elevator drive to increase a temperature of the at least one component without using the elevator drive to operate an associated elevator system.

Elevator drive control to protect drive components from moisture

According to one embodiment, a method of operating an elevator system is provided. The method includes detecting, using a controller, when an external power source is unavailable. The method also includes controlling, using the controller, a plurality of components of the elevator system. The controlling comprises operating at least one of an elevator car, a drive unit, an inverter and a brake. The method further includes detecting, using the controller, an original direction of travel of the elevator car. The method yet further includes detecting, using the controller, a mode of the elevator car, wherein the mode includes at least one of a motoring mode, a near balance mode, and a regenerative mode. The method includes determining, using the controller, a target floor. The method also includes adjusting, using the controller, a velocity of the elevator car to reach the target floor in response to the mode detected.

Growing community of inventors

Farmington, CT, United States of America

Prasanna Nagarajan