PEM Sudden-Stop Protection Using Local Current-Voltage Detection
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Solution Overview
Problem
Power electronics modules (PEMs) are vulnerable to failure events due to sudden stop conditions, such as unplugging an electric vehicle or battery pack, leading to excess energy accumulation and potential damage to the system.
Innovation Solution
Implementing control circuitry in PEMs to detect sudden stop conditions by monitoring output current and voltage changes, and rapidly turning off switching elements to prevent energy accumulation, with the ability to communicate status signals to a main controller.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the PEM uses a main system controller to detect and respond to sudden stop conditions, then the control logic can be centralized and managed, but the response time is too slow due to communication latency, causing excess energy accumulation and potential failure events
Solution Approach 1:
The control function is segmented between the main system controller and local control circuitry. The local control circuitry within each PEM independently monitors output conditions and executes immediate protective actions, while the main controller handles higher-level management. This segmentation eliminates communication latency for critical responses.
Solution Approach 2:
The local control circuitry is pre-configured with detection thresholds and protective logic, enabling it to immediately respond to sudden stop conditions without waiting for main controller instructions. The system performs preliminary setup of protection mechanisms that activate automatically when conditions are met.
2Reliability
If the PEM rapidly turns off switching elements to prevent excess energy accumulation during sudden stop conditions, then failure events are avoided, but the sudden change in current can cause voltage spikes that stress the circuitry
Solution Approach 1:
The control circuitry monitors output conditions continuously and detects sudden stop conditions before excess energy accumulation reaches dangerous levels. By intervening early in the process, the system prevents the buildup of harmful energy while avoiding the need for abrupt switching that would generate voltage spikes.
Solution Approach 2:
The control system dynamically adjusts the switching elements based on real-time output conditions. Rather than abrupt on/off switching, the system modulates the switching elements to gradually reduce power delivery, thereby preventing both energy accumulation and voltage spike generation.
3Productivity
If multiple PEMs are connected in parallel to provide faster charging, then the charging rate increases, but a sudden stop condition in one PEM can cause negative current flow that may damage the affected PEM
Solution Approach 1:
Each PEM's control circuitry independently monitors its own output current and detects negative current flow conditions caused by sudden stops. The system uses this feedback to immediately adjust the switching elements and prevent damage, while the main controller receives notifications to coordinate system-wide responses.
Data Source
AI summary
Systems and methods for operating a PEM including control circuitry are provided herein. The operation includes detecting, using the control circuitry, a drop in output current of the PEM, detecting, using the control circuitry, an increase in output voltage of the PEM, and in response to detecting the drop in output current and detecting the increase in output voltage, turning off the PEM using the control circuitry. Turning off the PEM may protect circuitry of the PEM from an interruption of a continuous power flow.