Multimode Converter Voltage Handling for EV Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing charging systems for rechargeable energy storage systems, such as batteries in electric vehicles, face challenges when the peak line voltage exceeds the storage system voltage, leading to uncontrollable current flow and potential damage, especially when the energy storage system is at a low state-of-charge.
Innovation Solution
A multimodal converter system that includes a relay/contactor, inductor, capacitor, and additional sense circuitry, allowing for operation in both boost and boost-buck modes to safely handle high line-in voltages relative to the energy storage system voltage, enabling efficient and safe charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional voltage converter topology is used, then the system can charge the energy storage system under normal voltage conditions, but it cannot handle the case when peak line voltage exceeds the storage system voltage, leading to uncontrollable current flow and potential damage
Solution Approach 1:
The patent implements a dynamic converter topology that can switch between boost mode and boost-buck mode based on the relationship between line voltage and storage system voltage. The controller monitors voltage conditions and dynamically reconfigures the converter circuitry, enabling the system to adapt to varying voltage conditions while maintaining safety and preventing uncontrolled current flow.
Solution Approach 2:
The patent creates a universal charging system that can handle multiple voltage scenarios: when peak line voltage is less than storage voltage (boost mode), when peak line voltage equals storage voltage, and when peak line voltage exceeds storage voltage (boost-buck mode). This multi-functional capability allows a single converter design to serve diverse operating conditions without requiring separate charging systems.
2Adaptability or versatility
If additional components are added to handle high line voltage conditions, then the system can safely charge under all voltage conditions, but the device complexity and cost increase
Solution Approach 1:
The patent merges the boost converter and buck converter functionalities into a single integrated multimodal converter structure. By combining these functions and sharing common components (such as switches, inductors, and capacitors) between the two modes, the system achieves enhanced voltage handling capability without proportionally increasing component count or complexity. The controller integrates the logic for both modes, further reducing overall system complexity.
Solution Approach 2:
The patent designs a universal converter architecture that performs multiple functions: it operates as a boost converter when line voltage is lower than storage voltage, and as a boost-buck converter when line voltage exceeds storage voltage. This multi-functional design allows the same hardware structure to handle diverse voltage conditions, avoiding the need for separate dedicated circuits for each mode and thereby reducing overall complexity.
3Ease of manufacture
If the converter operates in boost mode only, then the design is simpler, but it cannot charge when peak line voltage exceeds the storage system voltage
Solution Approach 1:
The patent transitions from a static boost-only converter design to a dynamic multimodal converter that can switch between boost mode and boost-buck mode. The controller dynamically selects the appropriate operating mode based on real-time voltage conditions, enabling the system to charge under all voltage scenarios while maintaining a relatively simple base design that builds upon the conventional boost converter structure.
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 system effectively provides high energy to the energy storage system while preventing damage, allowing for efficient and safe charging even when the line voltage is higher than the storage system voltage, with the ability to switch between boost and boost-buck modes to manage voltage differences and ensure safe operation.
Implementation Method 1
The suggested charging system and the suggested method are defined by the features of the independent claims. Embodiments are defined in the dependent claims. In the following, the first mode and the second mode of the converter operation are referred to as a 'boost mode' and a 'boost-buck mode', respectively.
Data Source
Figure 1
Figure 2
AI summary
A charging method using a multiphase line voltage for charging an energy storage system (ESS) using a polyphase motor drive circuit communicated to a polyphase motor, the polyphase motor drive circuit including a plurality M of driver stages, one driver stage for each phase of the polyphase motor with each driver stage coupled across the energy storage system, the method including the steps of: (a) determining a charge mode responsive to a comparison of the multiphase line voltage to a voltage of the energy storage system, the determined charge mode including a boost mode when the voltage of the energy storage system has a first predetermined relationship to the multiphase line voltage and the determined charge mode including a boost-buck mode when the voltage of the energy storage system has a second predetermined relationship to the multiphase line voltage; (b) converting, when the charge mode includes the boost mode, the multiphase line voltage to a first charging voltage using a first set of N number of the plurality of driver stages, with N less than M, wherein the first charging voltage is communicated to the energy storage system, and wherein the first charging voltage is greater than the multiphase line voltage; and (c) converting, when the charge mode includes the boost-buck mode, the multiphase line voltage to a second charging voltage using a second set of P number of the plurality of driver stages when in the boost-buck mode, with P greater than N, wherein the second charging voltage is communicated to the energy storage system, and wherein the second charging voltage is less than the multiphase line voltage.