Multilevel Energy Converter Control With Coordinated Module Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multi-level energy converters are complex, costly, and inefficient due to uncoordinated switching of modules, requiring numerous sensors and bulky output filters, which increases losses and complexity, especially when dealing with a large number of conversion modules.
Innovation Solution
A control device with a main controller that estimates input voltage and current values using estimators, allowing coordinated switching at high frequencies, reducing the need for high-speed sensors and communication, and minimizing filter size while maintaining regulation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If uncoordinated switching of conversion modules is used, then each module can operate independently with simple local control, but the overall system complexity increases and efficiency decreases due to cumulative switches and lack of coordination
Solution Approach 1:
The system divides control into hierarchical levels: a central controller manages overall coordination and timing for all conversion modules, while local controllers handle individual module operations. This segmentation allows independent module operation under centralized coordination, reducing overall system complexity while maintaining operational independence.
Solution Approach 2:
The central controller receives status information from all conversion modules and sends coordinated switching commands back to local controllers. This feedback mechanism ensures synchronized operation across modules, optimizing system efficiency while maintaining manageable complexity through centralized management.
2Manufacturing precision
If high switching frequency is used, then control precision and regulation accuracy improve, but the requirement for high-speed sensors and communication increases complexity and cost
Solution Approach 1:
The central controller pre-calculates optimal switching sequences and commands before execution, preparing control signals in advance. This preliminary action allows the system to achieve high switching frequencies with standard sensors and communication interfaces, as the controller anticipates and prepares commands rather than reacting in real-time to each switching event.
Solution Approach 2:
The system dynamically adjusts switching frequencies and command timing based on operational conditions. The central controller modulates the rate of switching commands to match system needs, achieving high precision when required while reducing communication burden during steady-state operation, thus balancing accuracy with complexity.
3Measurement precision
If numerous sensors are used for each conversion module, then measurement precision improves, but the cost and complexity of the control device increases
Solution Approach 1:
The central controller serves multiple functions: it acts as a master coordinator for all modules, a data aggregator receiving information from all local controllers, and a command distributor sending synchronized switching commands. This multi-functionality consolidates control capabilities, reducing the need for dedicated complex control circuits in each module while maintaining precise measurement and control.
Solution Approach 2:
The patent merges control functions by having the central controller aggregate data from all conversion modules and generate coordinated switching commands. This consolidation combines measurement and control functions at a central point, reducing overall system complexity while maintaining the precision needed for high-frequency operation through centralized data processing.
4Reliability
If bulky output filters are used at each conversion module, then output voltage quality improves, but the size, weight, and losses of the system increase
Solution Approach 1:
The coordinated switching strategy ensures continuous and optimized power transfer through the conversion modules. By synchronizing module operations, the system maintains smoother current and voltage waveforms, reducing the need for large filtering components at each module while maintaining output quality and reducing energy losses associated with bulky filters.
Data Source
AI summary
An electronic control device controls an energy converter delivering a total output voltage and/or an output current from a plurality of elementary DC input voltages, each coming from a respective source of energy. The converter has a number of conversion modules, each receiving an elementary DC input voltage from a respective source and delivering an elementary output voltage. The conversion modules are connected in series by the outputs thereof and the total output voltage is equal to the sum of the elementary output voltages. Each conversion module includes a number of switches for converting the elementary DC input voltage into the respective elementary output voltage. The control device has a number of elementary controllers and a main controller connected to the elementary controllers. Each elementary controller is associated with a respective conversion module and controls the switches of the module.