Hoist Control Cooling System for Variable Frequency Drive
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Solution Overview
Problem
Traditional suspension work platform hoist systems lack control over acceleration and deceleration, leading to jarring movements and premature wear, posing safety risks to occupants and equipment.
Innovation Solution
A powered controlled acceleration suspension work platform hoist system utilizing a variable frequency drive with electronic switching devices and a cooling system, allowing precise control of motor power and temperature management to regulate acceleration and deceleration, and incorporating a cooling system with sensors and controllers to maintain optimal operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional across-the-line starters are used to start the motor, then the motor starts quickly, but the platform experiences jarring acceleration that is dangerous to occupants and anchorage points
Solution Approach 1:
The patent applies parameter changes by transitioning from fixed-speed motor operation to variable-speed operation through a variable frequency drive (VFD). The VFD adjusts the frequency and voltage of power supplied to the motor, enabling controlled acceleration profiles that gradually increase speed rather than instantaneously jumping to full speed, thereby eliminating jarring movements while maintaining the ability to reach required operating velocities.
Solution Approach 2:
The patent replaces the traditional mechanical across-the-line starting mechanism with an electrical control system (VFD) that uses electronic switching devices to control motor power delivery. This substitution allows for smooth, controlled acceleration by modulating electrical parameters rather than relying on mechanical switches that cause abrupt start conditions.
2Device complexity
If traditional systems provide no control over powered deceleration, then the system is simple, but the platform stops instantaneously causing repeated starting and stopping that wears equipment and endangers occupants
Solution Approach 1:
The patent replaces the absence of deceleration control (simple system) with an active electronic control system (VFD) that provides regulated deceleration. The VFD controls the motor's braking and coasting phases, enabling smooth, controlled deceleration that prevents instantaneous stops, reduces equipment wear from repeated hunting, and eliminates safety hazards to occupants while maintaining manageable system complexity.
Solution Approach 2:
The patent applies dynamics by introducing variable deceleration rates that can be adjusted based on operating conditions. The system dynamically controls the motor's power output during deceleration, allowing for optimized stopping profiles that balance equipment protection, occupant safety, and operational efficiency, rather than using fixed instantaneous stopping.
3Ease of operation
If variable frequency drive is used to control motor power, then acceleration and deceleration are controlled, but substantial heat is generated requiring a cooling system
Solution Approach 1:
The patent introduces a cooling system as an intermediary component to manage the thermal byproduct of VFD operation. The cooling system includes temperature sensors that monitor inverter and ambient temperatures, and cooling devices (such as fans or heat sinks) that actively remove heat from the inverter, thereby enabling continuous controlled acceleration operation without thermal damage to the electronics.
Solution Approach 2:
The patent implements feedback control through temperature sensors that continuously monitor the inverter temperature and ambient temperature. This feedback information is used by the control system to adjust cooling system operation, ensuring that heat generation from controlled acceleration is managed while maintaining optimal operating temperatures for the VFD components.
4Device complexity
If traditional single-speed motors are used, then the system is simple, but velocity cannot be adjusted to match particular working conditions
Solution Approach 1:
The patent applies parameter changes by replacing fixed-speed motors with variable-speed motors controlled by a variable frequency drive. The VFD adjusts the electrical parameters (frequency and voltage) supplied to the motor, enabling continuous velocity adjustment to match different working conditions while maintaining manageable system complexity through standardized control components.
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
The system provides controlled acceleration and deceleration, reducing wear and safety risks, while enabling adjustable working velocities and redundant power supply capabilities for enhanced reliability.
Implementation Method 1
The inverter cooler is in physical contact with at least a portion of inverter and in physical contact with a portion of one of the plurality of enclosure sidewalls
Implementation Method 2
The ambient cooler is also located within the sealed control enclosure and receives the ambient cooling signal from the cooling system controller. The ambient cooling signal controls the amount of heat that the ambient cooler removes from the control enclosure
Implementation Method 3
The inverter temperature sensor measures the temperature of the inverter and generates an inverter temperature signal
Implementation Method 4
The ambient temperature sensor measures the temperature of the ambient air in the sealed control enclosure and generates an ambient temperature signal
Data Source
AI summary
The hoist control cooling system for preferentially cooling components of a variable frequency drive that is controlling a hoist motor. The cooling system includes an inverter temperature sensor, an ambient temperature sensor, a cooling system controller, an inverter cooler, and an ambient cooler. The inverter temperature sensor measures the temperature of the inverter and generates an inverter temperature signal. The ambient temperature sensor measures the temperature of the ambient air in the sealed control enclosure and generates an ambient temperature signal. The cooling system controller communicates with the inverter temperature sensor and the ambient temperature sensor by receiving the inverter temperature signal, the ambient temperature signal, and generating both an inverter cooling signal, and an ambient cooling signal. The inverter cooling signal controls the cooling of the inverter. Similarly, an ambient cooling signal switches the ambient cooler on, thereby cooling the ambient air temperature in the sealed control enclosure.