Multiple Drive System for Heavy Load Startup Current Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heavy load applications, such as vertical mills, face excessive heating and waiting times due to high starting currents and thermal stress during startup, especially when using drives without frequency converters, leading to inefficient and costly operations.
Innovation Solution
A multiple drive system with a plurality of drive trains that can be successively activated and deactivated according to a predefined strategy, allowing for automatic activation of the drive train with the lowest temperature during repeated startups, reducing starting current and thermal stress, and eliminating the need for expensive converters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single drive train is used for heavy load applications, then the starting current is high, but the thermal stress and waiting time increase excessively
Solution Approach 1:
The drive system is divided into multiple independent drive trains (at least two), allowing the total load to be segmented across multiple units. During startup, only one drive train is activated while others remain inactive, reducing the peak starting current demand on each individual drive train and eliminating the need for cooling waiting periods between repeated startups.
2Power
If starting aids are used to reduce starting current, then the starting current is adjusted to a desirable level, but excessive heating of drive components occurs
Solution Approach 1:
The drive system is divided into multiple independent drive trains (at least two), allowing the total load to be segmented across multiple units. During startup, only one drive train is activated while others remain inactive, reducing the peak starting current demand on each individual drive train and eliminating the need for cooling waiting periods between repeated startups.
3Device complexity
If a single drive train is used, then the device complexity is low, but the wear on drive components increases
Solution Approach 1:
The drive system is divided into multiple independent drive trains (at least two), allowing the total load to be segmented across multiple units. During startup, only one drive train is activated while others remain inactive, reducing the peak starting current demand on each individual drive train and eliminating the need for cooling waiting periods between repeated startups.
Solution Approach 2:
The control device implements periodic action by cyclically switching between different drive trains for startup operations. After one drive train completes a startup cycle, the system switches to another drive train for the next startup, allowing the first drive train to cool down and rest. This periodic rotation of active drive trains reduces wear and thermal stress on individual components.
Data Source
AI summary
A multiple drive for a heavy load application includes a plurality of drive trains which are activated such that individual ones of the plurality of drive trains are successively activated automatically during startup of the heavy load application as part of a predefined activation strategy according to a predefined activation scheme and an activation sequence defined therein. In the event of a repeated start of the heavy-load application, a different activation scheme can be used for the activation.