Matrix Switch Driver Circuit Without Auxiliary Power or Optocouplers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current active equalization technologies for battery management systems in electric vehicles face challenges such as increased EMI, complex structure, and high costs due to the use of auxiliary power sources and optical isolation devices.
Innovation Solution
A power-supplying and driving circuit for an active equalization matrix switch that includes a boost circuit and a constant current source circuit, eliminating the need for transformers and auxiliary power sources, thereby reducing EMI and complexity while minimizing mistaken turn-on.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If auxiliary power source and optical isolation device are adopted for controlling matrix switches, then driving capability is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the auxiliary power source and optical isolation devices from the system, replacing them with a simplified control approach that uses the existing battery pack power to directly drive the matrix switches through proper circuit design, thereby reducing device complexity while maintaining driving capability
Solution Approach 2:
The patent makes the existing power supply circuit serve multiple functions: it provides power to the battery management system and simultaneously provides the driving voltage for the matrix switches, eliminating the need for separate auxiliary power sources and reducing overall system complexity
2Power
If auxiliary power source is introduced to drive matrix switches, then driving voltage is improved, but EMI problem worsens
Solution Approach 1:
The patent converts the potential EMI issue into a benefit by designing the control circuit to use low-side switching topology where the switch connects to ground rather than high voltage, and by using the existing power ground as the reference, thereby achieving high driving voltage capability while minimizing EMI generation
3Reliability
If optical isolation device is used for controlling matrix switches, then isolation performance is improved, but device complexity and cost increase
Solution Approach 1:
The patent removes the optical isolation devices from the control circuit and replaces them with direct electrical control using MOSFETs and proper level-shifting techniques, achieving the necessary isolation through circuit topology design rather than physical isolation components, thereby reducing complexity and cost
Solution Approach 2:
The patent introduces intermediate control elements such as level-shifting circuits and gate driver stages that provide the necessary electrical isolation and voltage level adaptation without requiring optical isolation, serving as mediators between the control logic and the power switches
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
The proposed circuit effectively reduces EMI, simplifies the structure, and lowers costs by providing a stable high potential for driving matrix switch circuits without transformers, ensuring reliable operation and avoiding mistaken turn-on.
Implementation Method 1
a boost circuit, a constant current source circuit and a driver, where the boost circuit includes a first input end and a first output end; the first input end of the boost circuit is connected to the positive pole of a battery pack of a matrix switch circuit; the first output end of the boost circuit is connected to the constant current source circuit so as to provide high potential for the constant current source circuit to drive the matrix switch circuit
Data Source
AI summary
Disclosed is a power-supplying and driving circuit of an active equalization matrix switch of a battery management system of a vehicle. The power-supplying and driving circuit includes a boost circuit, a constant current source circuit and a driver. The boost circuit includes a first input end and a first output end; the constant current source circuit includes a constant current driving signal output end; the first input end is connected to the positive pole of a battery pack of a matrix switch circuit; the first output end is connected to the constant current source circuit to provide high potential for the constant current source circuit to drive the matrix switch circuit; the constant current driving signal output end is connected to the matrix switch circuit to drive the matrix switch circuit; and the driver is used for controlling the constant current source circuit to output a constant current driving signal.