Thyristor Starter Control for Gate Pulse Abnormality Detection
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Solution Overview
Problem
Thyristor starting devices face challenges in detecting gate pulse abnormalities without increasing device size and cost, and simplifying the control circuit configuration.
Innovation Solution
Incorporating a control unit that sets a phase control angle for the gate pulse and an abnormality detection unit to compare the DC current with a command value, allowing for abnormality determination based on this comparison, eliminating the need for a dedicated monitoring circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dedicated monitoring circuit is provided to detect gate pulse abnormalities, then detection reliability is improved, but device size and cost increase
Solution Approach 1:
The patent merges the gate pulse monitoring function with the existing current control unit by integrating an abnormality detection unit that uses the same DC current detection values and command values already available in the control system. This eliminates the need for separate dedicated monitoring circuits while maintaining detection capability.
Solution Approach 2:
The control unit is designed to serve multiple functions: it controls the converter current, detects DC current values, and simultaneously monitors gate pulse abnormalities by comparing detection values with command values. This multi-functionality reduces the need for separate dedicated components.
2Reliability
If a determination circuit is provided to detect gate pulse abnormalities, then detection reliability is improved, but control circuit complexity increases
Solution Approach 1:
The abnormality determination function is merged into the existing control unit by adding a comparison mechanism that uses already-available detection values and command values. This integration avoids creating a separate complex determination circuit while achieving the same protective function.
Solution Approach 2:
The system uses feedback comparison between the detected DC current value and the command value to determine gate pulse abnormalities. This feedback mechanism is implemented within the existing control unit structure, avoiding additional circuit complexity.
Data Source
AI summary
A thyristor starting device includes: a converter which converts AC power supplied from an AC power source into DC power; a DC reactor which smooths a DC current; an inverter which converts the DC power provided from the converter into AC power, and supplies the AC power to a synchronous machine; a gate pulse generation circuit which generates a gate pulse to be provided to thyristors of the converter and the inverter; a control unit which sets a phase control angle of the gate pulse to be provided to the thyristors of the converter, by controlling a current of the converter such that the DC current flowing into the DC reactor matches a current command value; and an abnormality detection unit which compares a detection value of the DC current with the current command value, and determines an abnormality in the gate pulse based on a comparison result.