DC-DC Converter Voltage Command Resolution via Scaling and Offset
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional low voltage DC-DC converters experience degraded resolution and output current ripple due to increased PWM switching frequency, which affects the performance and durability of eco-friendly vehicles.
Innovation Solution
A system and method that reduce the variable range of the voltage command signal through a scale part and an offset part, increasing the resolution of the voltage command signal by varying the first voltage command signal based on a preset scale ratio and adding an output from both parts, followed by smoothing and adjusting the semiconductor element operation to minimize output current ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the PWM switching frequency is increased to improve response performance, then the response speed is improved, but the resolution is degraded causing output current ripple
Solution Approach 1:
The voltage command signal is divided into two independent components: a scale part that provides coarse adjustment and an offset part that provides fine adjustment. This segmentation allows the system to achieve both high response speed (through the scale part) and high resolution (through the offset part) without the trade-off that normally exists between these parameters.
Solution Approach 2:
The invention introduces a new dimension to the voltage command signal by adding an offset component that operates independently from the scale component. This dimensional addition enables the system to resolve the contradiction between response speed and resolution by providing both coarse and fine control dimensions simultaneously.
2Measurement precision
If the variable range of the voltage command signal is reduced through scale and offset parts, then the resolution is increased, but the circuit complexity increases
Solution Approach 1:
The invention changes the parameters of the voltage command signal by applying different scale factors and offset values to different portions of the control range. The scale part uses a first scale factor for coarse control while the offset part uses a second scale factor for fine control, thereby increasing resolution without requiring a complete redesign of the circuit architecture.
Solution Approach 2:
The offset part acts as an intermediary that bridges the gap between the coarse scale part and the final high-resolution voltage command. By introducing this intermediate offset component, the system achieves fine resolution control while keeping the overall circuit structure relatively simple and modular.
Data Source
AI summary
A system for improving resolution of a voltage command of a low voltage DC-DC converter is provided. The system includes a voltage command signal generator that generates a first voltage command signal having a magnitude of a first specific range for a first voltage command of the low voltage DC-DC converter and a scale part that varies the first voltage command signal generated by the voltage command signal generator based on a preset scale ratio. An offset part sets a minimum value of a variable range of the first voltage command signal of the low voltage DC-DC converter. A resolution increasing part reduces the variable range of the first voltage command signal of the low voltage DC-DC converter by adding an output of the scale part and an output of the offset part.