ECU Power Supply Control for Fast Load Current Response
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Solution Overview
Problem
Automatic driving electronic control units (ECUs) face challenges in reducing power supply voltage variation due to load current changes while maintaining high responsiveness and power efficiency, as increasing switching frequency degrades power efficiency and adding capacitance or multiple voltages increases costs.
Innovation Solution
A dual power supply circuit system where a calculation unit predicts current changes and adjusts both first and second power supply voltages using control signals to manage inductor current speed and voltage division ratios, optimizing power supply responsiveness and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the switching frequency is increased to improve output current responsiveness, then the responsiveness is improved, but power efficiency is degraded
Solution Approach 1:
The patent applies dynamics by making the switching frequency variable rather than fixed. The control unit dynamically adjusts the switching frequency based on the operating conditions and load requirements, allowing the system to achieve high responsiveness when needed while maintaining power efficiency during normal operation. This is implemented through the control unit that adjusts the switching frequency of the switching power supply circuit based on voltage detection results and operational needs.
Solution Approach 2:
The patent changes the parameter of switching frequency from a constant value to a variable parameter that can be adjusted according to system needs. By modifying the switching frequency parameter dynamically, the system can optimize both responsiveness and power efficiency depending on the operational context, resolving the contradiction between these two requirements.
2Stability of the object's composition
If the capacitance of the capacitor is increased to suppress power supply voltage variation, then the voltage variation is suppressed, but the cost increases
Solution Approach 1:
The patent replaces the passive mechanical/electrical approach of using large capacitors with an active control system. Instead of relying on capacitor size to suppress voltage variation, the system uses a control unit that detects voltage changes and actively adjusts the switching frequency and duty cycle to maintain voltage stability. This substitution of active control for passive components reduces cost while maintaining stability.
Solution Approach 2:
The control system performs self-service by automatically detecting power supply voltage variations and adjusting its operation to compensate. The control unit monitors the voltage and self-regulates the switching parameters to maintain stable output, eliminating the need for oversized capacitors and reducing overall system cost.
3Speed
If the inductor value is reduced to improve output current responsiveness, then the responsiveness is improved, but the ripple voltage increases
Solution Approach 1:
The patent applies dynamics by adjusting the switching frequency in response to the reduced inductor value. When a smaller inductor is used to improve responsiveness, the control unit dynamically increases the switching frequency to compensate for the increased ripple voltage. This dynamic adjustment maintains both responsiveness and acceptable ripple levels simultaneously.
Solution Approach 2:
The control system takes preliminary anti-action by anticipating the ripple voltage increase that would result from using a smaller inductor. The control unit pre-adjusts the switching frequency and duty cycle to counteract the expected ripple, thereby maintaining voltage stability while benefiting from the improved current responsiveness provided by the smaller inductor.
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 enhances the responsiveness of the output current to load current variations while suppressing power supply voltage variations at low cost and high power efficiency, supporting reliable automatic driving systems.
Implementation Method 1
a switching power supply circuit configured to supply the calculation unit with a power supply voltage
Implementation Method 2
a capacitance of a capacitor connected to a power supply is increased
Implementation Method 3
When the inductor value is reduced, a change speed of an inductor current increases
Data Source
AI summary
Provided is a highly reliable electronic control unit capable of improving responsiveness of an output current of a switching power supply to load current variation and suppressing power supply voltage variation accompanying the load current variation at low cost and with high power efficiency. Provided are: a calculation unit that performs signal processing; a first power supply circuit that supplies a first power supply voltage to the calculation unit; and a second power supply circuit that supplies a second power supply voltage to the first power supply circuit. The calculation unit has a function of outputting a control signal when a change in a consumed current of the calculation unit exceeds a predetermined threshold, and changes any one or both of a control scheme of the first power supply circuit and the second power supply voltage according to the control signal.