Multi-Phase Inverter Topology for Galvanically Separated EV Power Sources
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Solution Overview
Problem
The complexity and cost of power electronics in electric vehicles with multiple power storage, generation, and consumption elements are increased due to the high current and voltage requirements, particularly in systems with both battery and fuel cell power sources, necessitating a reduction in the interconnect topology and reuse of components for efficient energy transfer and charging.
Innovation Solution
A multi-phase inverter configuration using two 3-phase Analog Phase Voltage (APV) inverters, where one inverter is connected to a battery and the other to a fuel cell, sharing AC phases to drive a motor while maintaining galvanic separation, and utilizing H-bridges for connection to the electrical grid for charging and power reception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple DC/DC converters and inverters are used to connect battery and fuel cell to the motor, then the system can provide power from multiple sources, but the complexity and cost of power electronics increases
Solution Approach 1:
The patent combines the functions of multiple inverters into a single multi-phase inverter that can handle both battery and fuel cell power sources. The inverter has multiple DC inputs that can be independently controlled, allowing it to operate in different modes (battery-only, fuel cell-only, or combined) without requiring separate inverter circuits for each power source.
Solution Approach 2:
The inverter is designed with universal functionality to accept power from different DC sources (battery and fuel cell) and provide AC output to the motor. The control system can dynamically switch between different operating modes and power source combinations, making the inverter adaptable to various power supply configurations without requiring additional dedicated hardware for each mode.
2Reliability
If separate inverters are used for battery and fuel cell connections, then galvanic separation is maintained, but the cost of power electronics increases due to high current and voltage requirements
Solution Approach 1:
The inverter internally segments the DC input processing for different power sources, with separate control pathways for battery and fuel cell inputs. This segmentation maintains galvanic separation between the two DC sources while using a unified AC output stage, reducing the need for duplicate power electronic components that would be required if completely separate inverters were used.
Solution Approach 2:
The inverter acts as an intermediary device that receives power from both DC sources through isolated input stages and combines them at the AC output side. The control system mediates between the two power sources, managing their interaction while maintaining electrical isolation, thus achieving galvanic separation without requiring completely separate inverter systems.
Data Source
AI summary
An electrical system for operating an AC electric motor in conjunction with a DC electrical energy storage and a DC electrical energy source is presented. It includes a multi-phase inverter or set of inverters, wherein multiple AC phases of the inverter or inverters are coupled to the motor, and separate DC connections of the inverter or inverters are coupled to the DC electrical energy source and the DC electrical energy storage.