Power Converter Control Apparatus for Vehicle Generator Temperature Management
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Solution Overview
Problem
Existing power converter control systems for vehicles fail to effectively manage temperature rises in generator and control apparatus parts during regenerative energy generation, leading to potential overheating and damage, as they lack a specific countermeasure to limit field current and prevent excessive suppression of generated current.
Innovation Solution
A power converter control apparatus that computes a generated current suppression value based on temperature and rotation speed, using a field current detection and temperature detection system to control the field current, preventing excessive current suppression and maintaining temperatures within safe limits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If field current is lowered to reduce generated current and suppress heat generation, then temperatures in generator and control apparatus are lowered, but generated current is suppressed excessively even in regions where heat generation is small
Solution Approach 1:
The patent implements dynamic field current limiting by computing a rotation speed-dependent upper limit value for field current. Instead of using a fixed constant coefficient multiplication, the system adjusts the field current limit based on the generator's rotation speed, allowing higher field current (and thus higher generated current) at rotation speeds where heat generation is manageable, while enforcing stricter limits only where necessary to prevent overheating.
Solution Approach 2:
The patent changes the parameter of field current upper limit value from a static constant-coefficient multiplication to a dynamic value that varies with rotation speed. The system computes different upper limit values for different rotation speed ranges, optimizing the balance between heat suppression and power generation efficiency by adapting the current limit to the actual operating conditions.
2Reliability
If field current is lowered to prevent temperature rise, then heat generation is suppressed, but the region of normal power generation is reduced and generated current is limited excessively
Solution Approach 1:
The system dynamically adapts the field current upper limit based on rotation speed, enabling the generator to operate in normal power generation mode across a broader range of operating conditions. By making the current limit dynamic rather than static, the system maintains reliability through temperature control while preserving adaptability to different operating regions.
Solution Approach 2:
The patent implements parameter changes by establishing different field current upper limit values corresponding to different rotation speed ranges. This allows the system to maintain reliable temperature control while expanding the adaptable operating region, as the field current limit is adjusted appropriately for each operating condition rather than being constrained by a single conservative limit.
3Temperature
If constant coefficient multiplication is used to limit field current, then temperature is controlled, but generated current suppression is excessive at rotation speeds lower than the specified rotation speed
Solution Approach 1:
The patent implements dynamic adjustment of the field current upper limit based on rotation speed, allowing the system to maintain appropriate temperature control while avoiding excessive power suppression at low rotation speeds. The dynamic approach enables the field current limit to be optimized for each rotation speed range, preventing unnecessary restrictions on power generation capability.
Solution Approach 2:
The system changes the field current limit parameter from a uniform constant-coefficient value to rotation-speed-dependent values. This allows the parameter to be optimized for different operating conditions, ensuring adequate temperature control at high rotation speeds while maintaining sufficient power generation capability at low rotation speeds where heat generation is naturally lower.
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 solution effectively limits generated current to prevent overheating, broadens the region of normal power generation, and prevents heat-induced damage to generator, power converter, and control apparatus parts.
Implementation Method 1
a generator part (200) having an armature winding (201) and a field winding (202)
Implementation Method 2
an AC generator (102) for vehicle having an armature winding (201) and a field winding (202) and operating as a generator after an engine is started
Implementation Method 3
a power converting apparatus for vehicle using a switching element and an accompanying parasitic diode instead of diodes and adopting rectification by the switching element
Data Source
AI summary
A power converter control apparatus includes a power converter part having a bridge circuit formed of a switching element and a field circuit controlling conduction of a field winding in an AC generator, and a control apparatus part having a field current detector, a temperature detector detecting a temperature of a generator part, the power converter part, or the control apparatus part, a field current instruction computation portion computing a field current instruction value of the generator, a temperature rise suppression portion computing a generated current suppression value on the basis of an output of the temperature detector and computing a field current suppression value on the basis of the computed generated current suppression value, a field current instruction selection portion selecting the field current instruction value or the field current suppression value whichever is the smaller, and a field current control portion controlling a field current.