DC Bus Charging Facility With Autonomous Power Converter Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Fast charging of electric vehicles puts a high load on commercial power systems, requiring efficient management of power demand to reduce peak loads and utilize renewable energy sources effectively, while existing systems lack flexibility and require upper-level control units.

Innovation Solution

A charging facility with a simple configuration that combines power generation devices and storage systems through power converters connected to a DC bus, allowing independent automatic control based on voltage fluctuations, eliminating the need for an upper-level control unit and enabling flexible operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If fast charging is performed to reduce charging time, then charging speed is improved, but power demand peak increases

Engineering Contradiction:
Improvecharging speedVSAvoidpower demand peak
Core Design Contradiction:
SpeedVSPower

Solution Approach 1:

The storage device charges in advance during periods of low power demand or high renewable energy generation, storing energy before the fast charging event. This preliminary energy storage allows the system to deliver high power to the EV without creating a peak demand on the grid, as the energy was accumulated beforehand from multiple sources including solar power generation devices and system power supply.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If multiple power supply devices are combined to manage power demand, then power management capability is improved, but system complexity increases

Engineering Contradiction:
Improvepower management capabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Each power converter operates autonomously based on voltage fluctuations in the DC bus, determining its own power supply timing and amount without requiring coordination from an upper-level control unit. The storage device and multiple power supply devices self-regulate their operation based on real-time voltage conditions, eliminating the need for complex centralized control while maintaining flexible power management capability.

Inventive Principle:
Principle #25Self-service

3Extent of automation

If upper-level control unit is used to coordinate power supply timing, then power distribution control is improved, but device complexity increases

Engineering Contradiction:
Improvepower distribution controlVSAvoiddevice complexity
Core Design Contradiction:
Extent of automationVSDevice complexity

Solution Approach 1:

Each power converter independently monitors the DC bus voltage and automatically adjusts its power supply operation based on voltage fluctuations. When voltage drops, converters increase power supply; when voltage rises, they reduce or stop power supply. This decentralized self-regulation achieves automated power distribution without requiring an upper-level control unit, reducing device complexity while maintaining effective control.

Inventive Principle:
Principle #25Self-service

4Loss of energy

If renewable energy sources are prioritized, then energy efficiency is improved, but power supply stability deteriorates

Engineering Contradiction:
Improveenergy efficiencyVSAvoidpower supply stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system combines multiple power supply sources including solar power generation devices, storage devices, and system power supply into a unified DC bus architecture. Renewable energy is prioritized when available, but the system automatically integrates power from multiple sources based on real-time voltage conditions, ensuring stable power supply while maximizing renewable energy utilization. The storage device acts as a buffer to smooth out fluctuations from renewable sources.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3528362B1Charging facility and energy management method for charging facility
Publication Date: 2020.10.28 MITSUBISHI HEAVY IND LTD
  • EP3528362B1 patent drawingFigure 1
  • EP3528362B1 patent drawingFigure 2
  • EP3528362B1 patent drawingFigure 3

AI summary

A charging facility collects DC power supplied from a plurality of power supply devices in a DC bus, and then uses the DC power to charge an on-board rechargeable battery for an electric vehicle. In an energy management method for a charging facility, each power supply device operates under independent automatic control according to a change in voltage in the DC bus. An upper-level control unit which collectively controls a plurality of power supply sources is not required, and a plurality of power supply devices can be combined with a simple configuration achieved by merely connecting respective output terminals to the DC bus. In addition, the entire charging facility can be operated flexibly. Thus, it is possible to achieve a simple configuration and to allow flexible operation while a plurality of power converters are combined with a system power supply.