Modular Inverter Circuit for Low-Harmonic AC and Active Cell Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for generating AC voltage from multiple DC voltage sources face challenges in achieving high precision and efficiency due to differences in battery cell properties, leading to inefficient charge balancing and increased switching losses, and require complex communication systems that are limited by data transmission speed and harmonics in the generated AC voltage.
Innovation Solution
A modular inverter circuit arrangement comprising a cascade of inverter units connected to dedicated DC voltage sources, with a control device and data transmission system that uses a control line for unidirectional signal transmission and a data line for bidirectional data transmission, allowing for precise configuration and synchronization of inverter units to generate high-quality AC voltage with reduced switching losses and flexible use of DC voltage sources of varying ages and types.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If passive charge balancing is used to balance battery cells, then charge balancing is achieved, but valuable electrical energy is lost
Solution Approach 1:
The control device continuously monitors the charge states of individual battery cells through the data transmission system and dynamically adjusts the inverter unit configurations to achieve active charge balancing. This feedback mechanism enables real-time optimization of charge distribution without energy loss, replacing the passive resistive discharge method.
Solution Approach 2:
The system uses the battery cells themselves as active elements in the inverter units, where fully charged cells automatically serve as power sources for partially charged cells through the inverter configuration. This self-service approach eliminates the need for external balancing circuits and energy dissipation.
2Manufacturing precision
If the clock frequency of the inverter is increased to reduce voltage harmonics, then the quality of AC voltage is improved, but switching losses increase
Solution Approach 1:
The inverter is divided into multiple independent inverter units, each connected to individual battery cells. This segmentation allows for flexible configuration where not all units need to switch simultaneously, reducing overall switching frequency and losses while maintaining output voltage quality through coordinated operation of the units.
Solution Approach 2:
The control device dynamically configures the inverter units based on real-time battery cell states and load requirements, adjusting the number and arrangement of active units. This dynamic adaptation optimizes the switching frequency to match actual needs, avoiding unnecessary high-frequency switching and associated losses while maintaining voltage quality.
3Measurement precision
If a complex communication system is used for controlling inverter units, then precise control is achieved, but data transmission speed is limited and device complexity increases
Solution Approach 1:
The control device consolidates the control and communication functions for all inverter units into a single centralized unit. This merging eliminates the need for complex distributed communication networks between multiple controllers, reducing system complexity and data transmission requirements while maintaining precise control through centralized coordination.
Solution Approach 2:
The control device performs multiple functions including monitoring battery cell states, configuring inverter units, generating control signals, and managing charge balancing operations. This multi-functionality reduces the need for separate specialized components and communication protocols, simplifying the overall system while maintaining precise control capabilities.
Data Source
AI summary
A circuit arrangement for generating an AC voltage has at least one modular inverter including a cascade of inverter units, a control device for controlling the inverter units, and a data transmission system for signal transmission between the control device and the inverter units. Each of the inverter units is connected to a respective DC voltage source, has a control input and a data output and is configured, depending on control signals received from the control device via the control input, to make the respective DC voltage source available on the output side for generating the AC voltage. The data transmission system has a control line and at least one data line each connected to the control device. The control line is connected to the control inputs of the inverter units and the at least one data line is connected to the data outputs of the inverter units.