Synchronous Motor Miswiring Detection via Vector Control
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Solution Overview
Problem
Existing technologies for detecting miswiring and disconnection in synchronous motors driven by a single power converter are not applicable, as they are specifically designed for induction motors and do not address the unique challenges of synchronous motors.
Innovation Solution
A motor control apparatus with a vector control unit and an abnormality detection unit that divides currents into q-axis and d-axis components, using q-axis inductance, rotation speed, and d-axis voltage command values to accurately detect miswiring or disconnection in synchronous motors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a plurality of synchronous motors is driven by a single power converter, then the system complexity is reduced and cost is lowered, but the risk of miswiring and disconnection increases making detection difficult
Solution Approach 1:
The patent implements feedback by continuously monitoring the relationship between voltage commands and current responses during motor operation. The control apparatus measures actual current values, compares them with expected values based on voltage commands and motor parameters, and uses this feedback to detect miswiring or disconnection anomalies in real-time.
Solution Approach 2:
The patent introduces an intermediary detection mechanism that uses the power converter's existing voltage and current measurement capabilities as mediators to indirectly detect wiring anomalies. Instead of adding direct wiring sensors, the system uses electrical parameter relationships as intermediaries to infer miswiring or disconnection states.
2Productivity
If miswiring or disconnection occurs in synchronous motors, then the motors can still operate by being pulled by healthy phases, but excessive current flows causing potential burnout
Solution Approach 1:
The patent applies preliminary action by detecting miswiring or disconnection anomalies before excessive current causes motor burnout. The control apparatus continuously monitors electrical parameter relationships and identifies anomalies early in the fault development process, enabling preventive action before harmful effects occur.
Solution Approach 2:
The system uses feedback to continuously compare actual current consumption with expected values based on voltage commands and motor parameters. When miswiring or disconnection occurs, the feedback mechanism detects the deviation and triggers protective action to prevent excessive current damage.
3Device complexity
If existing induction motor detection methods are used for synchronous motors, then the detection approach is simple, but the detection accuracy is insufficient because the methods are not applicable to synchronous motor characteristics
Solution Approach 1:
The patent changes the detection parameters from generic induction motor parameters to synchronous motor-specific parameters. The control apparatus uses synchronous motor characteristics including q-axis inductance, d-axis voltage commands, and rotor position information to create detection methods tailored to synchronous motor operation, thereby improving detection accuracy.
Solution Approach 2:
The patent segments the detection approach into distinct phases: normal operation phase where electrical parameters are monitored, anomaly detection phase where deviations are identified, and fault confirmation phase where miswiring or disconnection is confirmed. This segmentation allows for systematic and accurate detection specific to synchronous motors.
Data Source
AI summary
A motor control apparatus applied to a structure in which a plurality of synchronous motors connected in parallel and mechanically coupled to each other is driven by a single power converter, includes a vector control unit and an abnormality detection unit. The vector control unit divides a current flowing in/out the synchronous motors into a q-axis current and a d-axis current and individually controls the divided currents based on a q-axis current command value and a d-axis current command value. The abnormality detection unit detects whether at least one synchronous motor is wrongly wired or is disconnected based on a q-axis inductance, the q-axis current command value, a rotation speed of the synchronous motors, and a d-axis voltage command value.