Electric Machine Ground Potential Stabilization
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Solution Overview
Problem
The existing electrical drive systems are vulnerable to damage and loss of control due to uncontrolled reference ground potential fluctuations caused by a ground strap tear, which can lead to overvoltage or critical voltage issues during generator or motor operation.
Innovation Solution
Monitoring the ground differential voltage between the engine block and vehicle body ground potentials, activating the electrical machine into emergency modes to stabilize the reference ground potential, and switching between current-emitting and non-current-emitting operating states to prevent uncontrolled voltage changes and maintain logic circuit functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the electrical machine is operated in generator or motor mode with a ground strap tear, then power conversion continues, but uncontrolled reference ground potential fluctuations cause overvoltage or critical voltage issues
Solution Approach 1:
The ground differential voltage is monitored in advance before critical voltage levels are reached. The logic circuit detects ground strap tears early and activates emergency modes preemptively, preventing uncontrolled voltage fluctuations before they damage the electric drive or cause loss of control
Solution Approach 2:
The electrical machine dynamically switches between different emergency operating modes (current-emitting generator mode and non-current-emitting motor mode) based on real-time ground differential voltage conditions. This dynamic adaptation allows continuous operation while maintaining voltage stability within safe ranges
2Reliability
If additional protective components are added to prevent ground strap tear damage, then reliability improves, but device complexity and cost increase
Solution Approach 1:
The existing electrical machine and logic circuit serve dual purposes: normal power conversion function and emergency protection function. The machine uses its own operational modes (generator/motor) to stabilize voltage during ground strap tears, eliminating the need for separate protective components and reducing system complexity
Solution Approach 2:
The electrical machine is designed to perform multiple functions: normal power conversion, emergency voltage stabilization, and self-protection against ground strap tear damage. This multi-functionality consolidates protection capabilities within existing components rather than requiring additional dedicated protective devices
Data Source
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AI summary
The invention relates to a method for operating an electric machine (110) comprising am electronic power converter (115) which is electrically connected to a reference ground potential (UB). A ground difference voltage between the ground potential (UB) and a reference mass potential (UR) is monitored and if the ground difference voltage exceeds an upper threshold, the electric machine (110) is operated in a current-outputting operating state and if the ground difference voltage reaches a lower threshold limit, the electric machine (110) is operated in a non-current outputting operational state.