Inverter Torque Limiting During Coolant Startup
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Solution Overview
Problem
Existing torque-limiting devices for electric rotating machines require complex data transmission systems to manage inverter temperatures, leading to increased size and power consumption when cooling apparatuses are oversized to prevent excessive temperature rises during coolant circulation.
Innovation Solution
Implementing a control apparatus that limits the electric power supply to the electric rotating machine upon coolant circulation startup and terminates this limitation after a predefined period, preventing excessive temperature increases without the need for extensive cooling apparatus capacity or complex communication systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cooling apparatus capacity is increased to prevent excessive temperature rise during coolant circulation startup, then the temperature control reliability is improved, but the device size and electricity consumption increase
Solution Approach 1:
The control apparatus performs preliminary action by detecting coolant circulation startup and proactively limiting the driving output before excessive temperature rise occurs. This preventive control eliminates the need for oversized cooling apparatus, as the system prepares for and manages temperature conditions in advance rather than requiring excessive cooling capacity to handle worst-case scenarios.
Solution Approach 2:
The control apparatus changes operational parameters by dynamically adjusting the driving output limitation based on coolant circulation status. When circulation startup is detected, the system activates output limitation with a predetermined value, thereby controlling temperature rise without requiring increased cooling apparatus capacity. This parameter adjustment resolves the contradiction by managing temperature through control rather than hardware scaling.
2Reliability
If data transmitting means with insulating means is provided to transmit inverter temperature data to control apparatus, then the temperature monitoring reliability is improved, but the device complexity increases
Solution Approach 1:
The control apparatus performs self-service by directly detecting coolant circulation startup status and autonomously determining when to limit driving output. This eliminates the need for separate temperature data transmission systems with insulating means, as the control apparatus independently monitors circulation conditions and makes control decisions without complex communication infrastructure.
Solution Approach 2:
The invention extracts and removes the complex data transmission system with insulating means from the overall system. Instead of relying on temperature data transmission from the inverter to the control apparatus, the system uses direct circulation status detection, thereby simplifying the device while maintaining reliability through alternative monitoring approach.
3Reliability
If torque limitation is implemented to reduce heat generation in inverter, then the temperature reliability is improved, but the productivity decreases
Solution Approach 1:
The control apparatus implements periodic action by applying torque limitation only during specific periods when coolant circulation startup is detected and before the coolant adequately cools the inverter. This time-limited control approach maintains inverter temperature reliability during critical startup phases while minimizing impact on overall productivity, as normal operation resumes once cooling is established.
Solution Approach 2:
The control apparatus applies partial action by limiting driving output only to the extent necessary during coolant circulation startup, rather than continuously limiting torque. This selective application of limitation maintains sufficient motor output for normal operation while providing targeted temperature control during the specific period when cooling effectiveness is insufficient.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively manages inverter temperatures during coolant circulation startup, reducing the risk of overheating without increasing the size or power consumption of the cooling apparatus, while maintaining driveability and simplifying control processes.
Implementation Method 1
a cooling apparatus for circulating coolant to the electric rotating machine and the power conversion circuit through a circulation channel
Data Source
AI summary
The control apparatus is for an electric rotating machine which is mounted as an engine on a vehicle together with a power conversion circuit to be connected to the electric rotating machine, and a cooling apparatus for circulating coolant to the electric rotating machine and the power conversion circuit through a circulation channel, including. The control apparatus includes a limiting means for performing a limiting operation to limit an amount of electric power supply from the inverter to the electric rotating machine each time a circulation starting timing of the coolant comes, and a terminating means for terminating the limiting operation after a lapse of a predefined period from start of the limiting operation.