Sensorless Pump No-Flow Detection Using Motor Parameter Changes
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Solution Overview
Problem
Existing sensorless pumping control applications face challenges in accurately detecting no flow conditions, leading to inefficient energy usage and inability to implement no flow shutdown or idle detection without additional conditions or pump states.
Innovation Solution
The introduction of a no flow idle speed detection scheme, utilizing motor operation parameters like power, current, and torque, combined with external flow or pressure signals, allows for effective no flow detection and shutdown in sensorless pumping control systems, enabling energy-saving operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If sensorless converter is used to obtain motor values (RPM and hp) as input signals, then motor operation parameters are available for control, but no flow detection based on system pressure drop becomes unachievable without additional sensors or conditions
Solution Approach 1:
The patent changes the detection parameters from traditional pressure-based measurements to motor operation parameters (power, current, torque) that are already available from the sensorless converter. By monitoring changes in these electrical parameters, the system can infer flow conditions without requiring additional pressure sensors or flow meters, thus resolving the contradiction between simplified device complexity and maintained measurement precision for no flow detection
Solution Approach 2:
The patent introduces an intermediary relationship where motor operation parameters serve as mediators to indirectly detect flow conditions. Instead of directly measuring pressure or flow, the system uses the correlation between motor electrical parameters and pump hydraulic performance to infer flow status, enabling no flow detection without additional sensors while maintaining adequate detection precision
2Reliability
If conventional no flow shutdown detection scheme is implemented, then no flow conditions can be detected using pressure drop, but additional no flow conditions or pump running states must be introduced
Solution Approach 1:
The patent enables the motor drive system to self-diagnose flow conditions using its own operational data (power, current, torque) without requiring external pressure sensors or complex additional detection systems. The sensorless converter already monitoring motor parameters for control purposes also provides the data needed for no flow detection, making the system self-sufficient and avoiding the need for additional pump running states or detection conditions
3Productivity
If motor runs continuously without no flow detection, then pump operates without interruption, but energy is wasted when there is no flow request
Solution Approach 1:
The patent implements feedback control by continuously monitoring motor operation parameters and using them to detect no flow conditions. When no flow is detected through analysis of power, current, or torque parameters, the system provides feedback to shut down or idle the pump, preventing energy waste. This feedback mechanism maintains productivity by ensuring the pump operates only when needed while eliminating energy loss during no flow conditions
Data Source
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Figure 3
Figure 4A~4B
AI summary
Apparatus is provided featuring a signal processor or processing module configured to receive signaling containing information about a pump no flow idle (NFI) state when the pump is running at a pump idle speed; and determine corresponding signaling containing information about whether the pump should remain in a no flow shutdown (NFSD) state or the pump NFI state, based upon the signaling received. The signal processor or processing module is configured to provide the corresponding signaling containing information about whether the pump should remain in the NFSD state or the NFI state.