Multi-Drive Position Synchronization via Dynamic Control Range Adjustment
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Solution Overview
Problem
Existing systems for controlling the position of multiple drives struggle to maintain synchronicity, especially at operating points near control limits, leading to potential torsional disturbances and instability.
Innovation Solution
A system and method that utilize a controller with setpoint limiters and compensating controllers to synchronize the position of multiple drives, including converter-fed electric motors, by determining and transmitting maximum and minimum values to ensure that the control range is adjusted to maintain synchronicity, even when one drive reaches its control limit, thereby reducing total torque on a shared shaft.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple drives are operated in position-synchronous manner without control range adjustment, then position synchronicity can be maintained in normal operating conditions, but position synchronicity is lost at operating points near control limits where one drive reaches its control limit
Solution Approach 1:
The control range limits are dynamically adjusted based on the operating state of connected drives. When one drive approaches its control limit, the system automatically reduces the control range of other drives to maintain position synchronicity. This dynamic adaptation allows the system to handle varying operating conditions while preserving synchronization reliability.
Solution Approach 2:
The system continuously monitors the control limits and operating states of all connected drives, using this feedback information to adjust control ranges in real-time. The controller receives status information from each drive and modifies the permissible control variable ranges accordingly, ensuring that position synchronicity is maintained even when operating near control limits.
2Reliability
If the control range is reduced to maintain position synchronicity at control limits, then position synchronicity is maintained, but the control precision and response capability are reduced
Solution Approach 1:
The control range adjustment is dynamic and state-dependent. The system maintains full control precision when drives operate within normal ranges, and only reduces control ranges when necessary to maintain synchronization at control limits. This dynamic approach minimizes the impact on control precision while ensuring synchronization reliability.
Solution Approach 2:
The system changes the parameter ranges of control variables based on operating conditions. By adjusting the permissible ranges of control variables dynamically, the system maintains optimal control precision in normal operation while preventing synchronization loss at control limits, thus resolving the contradiction between reliability and precision.
3Device complexity
If drives are connected on the same shaft without control coordination, then mechanical coupling is simple, but torsional disturbances occur due to uncoordinated torque output
Solution Approach 1:
The control system continuously monitors the operating state of each drive and uses feedback to coordinate torque output. By adjusting control ranges and monitoring control limits, the system ensures that drives operate in a coordinated manner, preventing uncoordinated torque changes that would cause torsional disturbances on the shared shaft.
Solution Approach 2:
The system performs preliminary coordination by pre-adjusting control ranges based on the operating states of connected drives. Before torque imbalances can occur, the controller proactively modifies the permissible control variable ranges to prevent uncoordinated torque output, thus maintaining torsional stability while keeping the mechanical coupling simple.
Data Source
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AI summary
Disclosed is a system comprising at least two regulated drive units, especially a converter-fed electric motor. Each drive unit encompasses a controller to which an input variable is fed. A setpoint can be predefined for respective setpoint limiters of the drive units, the actual values associated with the same time step are fed to a respective compensating controller, the output value of which is added to the output value of the respective setpoint limiter, and the result is fed to the controller as an input variable.