Motor Drive Apparatus Upper Arm ON Running Short Circuit
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Solution Overview
Problem
Existing motor drive apparatuses fail to perform upper arm ON running when a short-circuit abnormality occurs in the upper switching element, leading to repeated fail signal generation and unsuccessful operation.
Innovation Solution
A motor drive apparatus with a control device that stops the converter and sets the output of an ON signal to the short-circuited upper switching element as non-executable, preventing fail signal generation and enabling upper arm ON running by controlling power and regenerative operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an ON signal is input to the short-circuited upper switching element to perform upper arm ON running, then power supply from inverter to battery is enabled, but the converter generates repeated fail signals preventing successful operation
Solution Approach 1:
The patent extracts the problematic fail signal generation mechanism by detecting the short-circuit state of the upper switching element and excluding it from normal fail signal generation logic. When a short-circuit is detected, the system performs upper arm ON running without generating fail signals, thereby separating the short-circuit operation path from the normal failure detection path.
Solution Approach 2:
Instead of generating fail signals when the upper switching element receives an ON signal (which causes repeated loops), the patent inverts the logic by detecting short-circuit states and suppressing fail signal generation in this specific condition. This allows the system to operate in upper arm ON running mode without being blocked by erroneous fail signals.
2Reliability
If the converter is shut down when an abnormality occurs, then overvoltage of the smoothing capacitor is prevented, but power supply from inverter to battery cannot be performed
Solution Approach 1:
The patent dynamically adjusts the converter operation mode based on the type of abnormality detected. When a short-circuit in the upper switching element is detected, the system transitions to upper arm ON running mode, allowing power supply from inverter to battery. This dynamic adaptation enables the system to maintain productivity while ensuring overvoltage protection through appropriate mode selection.
Data Source
AI summary
An ECU (Electronic Control Unit) controls a converter such that the converter is stopped when a fail signal FCV is output. The ECU further controls an inverter such that power operation and regenerative operation by a motor generator are performed in a state in which output of an ON signal to an IGBT (Insulated Gate Bipolar Transistor) element is set non-executable, when the fail signal FCV is output due to the IGBT element becoming short-circuited.