Inverter Automatic Torque Boost Voltage Control
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Solution Overview
Problem
Existing inverters face issues with insufficient output voltage at the initial stage of driving, leading to potential overcurrent faults and passenger insecurity in elevator applications, as they lack adaptive load adjustment mechanisms.
Innovation Solution
An inverter system with a reference voltage determining unit, automatic torque boost voltage calculation, and load state detection to dynamically adjust output voltage based on load conditions, incorporating a preset manual boost voltage and automatic torque boost voltage, ensuring safe and stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a manual boost method is used to increase output voltage at low speed, then the output voltage is improved, but torque may be insufficient or excessive according to user setting and does not adapt to load amount
Solution Approach 1:
The patent implements an automatic torque boost mechanism that uses feedback from the detected load amount to dynamically adjust the boost voltage. The control unit detects the actual load on the induction motor and automatically adjusts the boost voltage accordingly, eliminating the need for manual setting and ensuring the boost voltage adapts to varying load conditions.
Solution Approach 2:
The system performs self-adjustment by automatically detecting load conditions and adjusting the boost voltage without user intervention. The control unit monitors the motor's operating state and autonomously determines the appropriate boost voltage level, making the system self-adapting to different load scenarios.
2Device complexity
If a fixed boost voltage is applied regardless of load amount, then the control is simplified, but output voltage becomes insufficient or excessive according to load amount
Solution Approach 1:
The control unit continuously monitors the load amount and uses this feedback information to automatically adjust the boost voltage. This feedback mechanism enables the system to maintain optimal output voltage across different load conditions without requiring complex manual control procedures.
3Device complexity
If output voltage is insufficient at initial stage of driving, then the system is simpler, but overcurrent may flow causing inverter fault or elevator sliding
Solution Approach 1:
The system applies torque boost voltage in advance during the initial driving stage and at low speeds, before the motor reaches its normal operating range. This preliminary voltage enhancement ensures sufficient starting torque and prevents overcurrent conditions that could cause inverter faults or elevator sliding, improving operational safety without requiring complex additional hardware.
Data Source
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AI summary
An inverter which supplies a load-adaptive boost voltage and drives an induction motor includes a reference voltage determining unit configured to determine a reference voltage according to a reference frequency on the basis of a predetermined a relationship between a voltage and a frequency, an inverter unit configured to drive the induction motor according to the reference voltage, and an automatic torque boost voltage calculation unit configured to determine an automatic torque boost voltage value according to a magnitude of an output current from the inverter to the induction motor, wherein the reference voltage determining unit adds a preset manual boost voltage value and an automatic torque boost voltage value to the reference voltage and outputs the resultant voltage value as a final reference voltage.