PM Synchronous Motor Drive Segmentation for Elevator Rescue Control
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Solution Overview
Problem
Elevator systems often face challenges in providing sufficient power during high load conditions due to the lack of high-power drives, leading to increased design costs and lengthy development times, as well as excessive costs associated with specialty components and availability issues.
Innovation Solution
A permanent magnet synchronous motor drive system with multiple phases and motor drives that can distribute torque and flux currents independently, featuring a controller and rescue module to manage failures by reconfiguring operation profiles and designating secondary drives as temporary primaries, ensuring continued operation and safe movement of the elevator car.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single large high-power drive is used to power the elevator machine, then sufficient power is provided for large elevator duty, but design costs and development time increase significantly
Solution Approach 1:
The patent divides the single large high-power drive into multiple smaller motor drives (first motor drive, second motor drive, third motor drive) that collectively provide the required power. Each motor drive is connected to separate phases of the multi-phase motor, allowing the system to achieve high power output without the complexity and cost of a single large drive unit.
2Power
If a single large high-power drive is used, then sufficient power is provided, but specialty components and component availability issues increase costs
Solution Approach 1:
By segmenting the drive system into multiple standard-power motor drives rather than one custom high-power drive, the patent uses commercially available components with better supply chain support. This approach reduces reliance on specialty components and improves manufacturing ease and component availability.
Solution Approach 2:
The patent designs the motor drive system so that each motor drive can potentially serve multiple phases or be reconfigured based on failure conditions. The controller can redistribute power commands among available drives, making each drive unit versatile and reducing the need for specialized single-function components.
3Device complexity
If multiple motor drives are used to distribute power, then cost and complexity are reduced, but system reliability decreases when a drive fails
Solution Approach 1:
The controller is pre-programmed with failure detection and redistribution logic. When a motor drive failure is detected, the controller automatically redistributes the power commands to the remaining functional drives without requiring manual intervention or system shutdown. This preliminary preparation ensures continuous operation and maintains reliability.
Solution Approach 2:
The patent dynamically changes operational parameters by redistributing torque and power commands among the remaining functional motor drives when a failure occurs. The controller adjusts the current distribution and torque commands to match the reduced capacity configuration, allowing the system to adapt and continue operating reliably.
4Reliability
If the elevator system operates with reduced capacity after drive failure, then continued operation is possible, but operation speed and efficiency are reduced
Solution Approach 1:
The patent allows the elevator system to operate with partial capacity using the remaining functional motor drives. Rather than completely shutting down the system, the controller distributes the required power among the available drives, enabling continued operation at reduced but sufficient speed for safe and functional elevator service.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables efficient and cost-effective power delivery to elevator systems by redistributing torque and flux currents, allowing for reduced operation and safe movement of the elevator car in case of drive failures, thereby minimizing downtime and repair costs.
Implementation Method 1
a permanent magnet (PM) synchronous electric motor including a plurality of phases
Data Source
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AI summary
A permanent magnet (PM) synchronous electric motor(34) includes a plurality of phases, and a plurality of motor drives(55,58) 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(44) is operatively connected to each of the plurality of motor drives to selectively control the PM synchronous electric motor, and a rescue module(120) 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.