Converter Imbalance Detection for 12-Phase Rectifier Transformers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In 12-phase rectifier transformers, an imbalance between AC voltage outputs from Δ-connection and Y-connection can cause current concentration in one diode bridge, leading to potential damage due to heat accumulation.
Innovation Solution
A converter with a current detector and imbalance detection unit that compares currents from both connections, triggering an alarm to stop the electric motor and prevent prolonged current concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a 12-phase rectifier transformer with Δ-connection and Y-connection is used to perform 12-phase rectification, then full-wave rectification can be performed and harmonics are prevented from leaking to the AC system, but current concentration in one diode bridge can occur leading to heat damage
Solution Approach 1:
The patent applies preliminary action by detecting current imbalance between the two diode bridges before heat damage occurs. The detection unit continuously monitors the current distribution and issues warnings or stops the system when imbalance exceeds a threshold, preventing the harmful effect of heat accumulation before it can cause damage to the diode bridge components.
2Reliability
If current imbalance detection is implemented, then heat damage to diode bridges can be prevented, but device complexity increases due to additional detection components
Solution Approach 1:
The patent applies universality by designing a detection unit that can serve multiple functions: it detects current imbalance, determines which diode bridge has excessive current, and can trigger warnings or system shutdown. This multi-functional approach avoids the need for separate detection and control systems, thereby limiting the increase in device complexity while achieving comprehensive protection.
3Measurement precision
If the system continuously monitors current to detect imbalance, then timely detection of current concentration is achieved, but energy consumption increases
Solution Approach 1:
The patent applies feedback by using the detected current imbalance information to control the system operation. When imbalance is detected, the system provides feedback through warnings or shutdown commands, allowing operation to continue normally during balanced conditions (low energy consumption) while enabling precise detection and response only when needed, thus balancing measurement precision with energy efficiency.
Data Source
AI summary
A converter includes a converter circuit that converts the AC voltages supplied from the Δ-connection and the Y-connection, which are two systems of a 12-phase rectifier transformer, to a DC voltage; a current detector that detects the current in a DC bus output from the converter circuit; and an imbalance detection unit that detects the occurrence of an imbalance between the current output from the Δ-connection and the current output from the Y-connection, the currents being detected by the current detector. The converter can detect an imbalance that occurs between the current flowing in the diode bridge on the Δ-connection side and the current flowing in the diode bridge on the Y-connection side.