Demolition Robot Motor Thermal Load Control Under Phase Imbalance
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Solution Overview
Problem
Conventional technologies fail to effectively address the issue of thermal damage to the motor damage in the technical problem of the motor, which is the technical problem. The technical problem is the inability to prevent thermal damage to the electric motor of a demolition robot due to imbalances in the three-phase electrical network, leading to partial thermal damage and reduced motor lifetime.
Innovation Solution
A demolition robot with a control unit that compares observed thermal damage to a predetermined normative standard, limiting thermal load and providing real-time monitoring and diagnosis to prevent thermal overload, using power regulation and heat-absorbing mediums to maintain optimal operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the demolition robot operates in a three-phase electrical network with imbalanced phases, then the motor is forced to work with electric current in the active phases, but this causes extreme temperature increase and thermal damage to the motor
Solution Approach 1:
The control unit performs preliminary monitoring of phase current imbalance before thermal damage occurs. By detecting imbalanced phases in advance and calculating partial thermal damage values, the system can take preventive action by limiting motor power output before extreme overheating occurs, thus avoiding thermal damage while maintaining operation continuity.
Solution Approach 2:
The control unit continuously monitors phase currents and provides feedback by calculating real-time partial thermal damage values. This feedback mechanism allows the system to adjust motor power output dynamically based on the accumulated thermal damage, preventing thermal overload while maintaining productivity. The feedback loop compares current thermal state against normative values and adjusts operation accordingly.
2Reliability
If the motor-circuit switch temporarily disconnects the supply voltage at thermal overload, then motor damage is prevented, but the motor operation is interrupted and productivity is reduced
Solution Approach 1:
Instead of completely disconnecting the motor at thermal overload, the control unit applies partial action by limiting the motor power output to a reduced level. This allows the motor to continue operating at lower power while still providing protection against thermal damage. The system calculates appropriate power limitations based on accumulated thermal damage, maintaining operation continuity while ensuring motor reliability.
Solution Approach 2:
The control unit dynamically adjusts motor power output based on real-time thermal damage calculations. Rather than a static on/off control, the system continuously modifies the power level to match the thermal state, allowing smooth transitions between different operating conditions. This dynamic control maintains productivity while preventing thermal overload through gradual power reduction.
3Device complexity
If conventional monitoring only detects phase current imbalance, then simple measurement is sufficient, but this is not sufficient to disclose all potential errors that may result in overheating
Solution Approach 1:
The control unit serves multiple functions: it monitors phase currents for imbalance detection, calculates partial thermal damage values, determines accumulated thermal damage, and controls motor power output. This multi-functional approach combines simple current sensing with sophisticated thermal analysis, achieving comprehensive overheating detection without requiring separate complex monitoring systems for each function.
Solution Approach 2:
The control unit acts as an intermediary that transforms simple phase current measurements into comprehensive thermal damage assessments. By introducing the calculation of partial thermal damage values as an intermediate step, the system bridges the gap between simple current monitoring and accurate overheating detection, enabling precise diagnosis without direct temperature sensing.
4Reliability
If the control unit limits motor power output based on accumulated thermal damage, then thermal load is reduced and motor protection is improved, but the productivity and output power are reduced
Solution Approach 1:
The control unit changes the power output parameter dynamically based on accumulated thermal damage. By adjusting the power level as a variable parameter rather than a fixed value, the system optimizes the balance between motor protection and productivity. The power output is modified in response to thermal conditions, extending motor lifetime while minimizing productivity loss through intelligent parameter adaptation.
Data Source
Figure 1~2
Figure 1A~1B
Figure 3A~4B
AI summary
The invention relates to a demolition robot (1), comprising a cable (12) intended to be connected to an electric network to power a motor (21), a pump (22) that is powered by the electric motor for generating a hydraulic flow to consumers (13), wherein the motor (21) is activable at varying thermal load values (FT), depending on the current consumer's (13) need for hydraulic power, a control unit (24) arranged to receive information about the thermal load (FT) on the motor, to determine a partial thermal damage value (SL, SM, SH) at various thermal loads (FT) on the motor. To minimize the risk of thermal damage to the motor, the control unit (24) is adapted to compare said partial thermal damage values (SL, SM, SH) with a normative partial thermal damage (A) and is adapted to limit the thermal load (FT) on the motor (21) to a maximum allowable thermal load value (PTmax), if the partial thermal damage value (SL, SM, SH) exceeds the normative partial thermal damage (A) at a predetermined value (A').