Vehicle Drive System Multi-Voltage Supply via Battery Capacitor Series

Solution Overview

Problem

Existing vehicle power supply systems cannot efficiently provide multiple power supply voltages without increasing vehicle weight and cost, as they require additional components like DC/DC converters to achieve higher voltages.

Innovation Solution

A vehicle drive system that connects batteries and capacitors in series to supply three power voltages directly, eliminating the need for DC/DC converters by using the total voltage of the battery and capacitor for high voltage, the battery for medium voltage, and individual battery cells for low voltage, with switches for easy connection/disconnection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a DC/DC converter is added to supply higher voltage power supply, then the power supply capability is improved, but the vehicle weight and cost increase

Engineering Contradiction:

Improvepower supply capabilityVSAvoidvehicle weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The battery is divided into multiple battery cells that can be independently connected or disconnected. By selectively connecting individual battery cells or groups of cells in series, the system can provide multiple voltage levels (higher voltage power supply, standard voltage power supply, low voltage power supply) without requiring additional DC/DC converters, thereby reducing vehicle weight while maintaining power supply versatility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically reconfigures the battery circuit by selectively connecting or disconnecting battery cells based on the required voltage level. Switches control the series connection of battery cells to adaptively provide different voltage outputs, eliminating the need for fixed-voltage power supplies and heavy DC/DC conversion equipment

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If a DC/DC converter is added to supply higher voltage power supply, then the power supply capability is improved, but the cost increases

Engineering Contradiction:

Improvepower supply capabilityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The battery is divided into multiple battery cells that can be independently connected or disconnected. By selectively connecting individual battery cells or groups of cells in series, the system can provide multiple voltage levels (higher voltage power supply, standard voltage power supply, low voltage power supply) without requiring additional DC/DC converters, thereby reducing vehicle weight while maintaining power supply versatility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically reconfigures the battery circuit by selectively connecting or disconnecting battery cells based on the required voltage level. Switches control the series connection of battery cells to adaptively provide different voltage outputs, eliminating the need for fixed-voltage power supplies and heavy DC/DC conversion equipment

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If the number of power storage elements is increased to supply higher voltage, then the power supply voltage is improved, but the vehicle weight increases

Engineering Contradiction:

Improvepower supply voltageVSAvoidvehicle weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The battery is divided into multiple battery cells that can be independently connected or disconnected. By selectively connecting individual battery cells or groups of cells in series, the system can provide multiple voltage levels (higher voltage power supply, standard voltage power supply, low voltage power supply) without requiring additional DC/DC converters, thereby reducing vehicle weight while maintaining power supply versatility

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system dynamically reconfigures the battery circuit by selectively connecting or disconnecting battery cells based on the required voltage level. Switches control the series connection of battery cells to adaptively provide different voltage outputs, eliminating the need for fixed-voltage power supplies and heavy DC/DC conversion equipment

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP3747682B1Vehicle drive system and vehicle

Publication Date: 2022.05.11 MAZDA MOTOR CORP

Figure 1
Figure 2
Figure 3

AI summary

A vehicle drive system 10 includes: a primary drive motor 16 and a secondary drive motor 20; a battery 18; a capacitor 22 that is connected in-series with the battery 18; a first power line 5a that supplies a total voltage of the battery 18 and the capacitor 22; a second power line 5b that supplies a battery voltage; and a third power line 5c that supplies a cell voltage. The first power line 5a, the second power line 5b, and the third power line 5c are configured that the battery voltage is higher than the cell voltage and that the total voltage is higher than the battery voltage.