DC/ETAC Power Conversion System Voltage Envelope Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power conversion systems face inefficiencies and complexity due to high switching losses and electromagnetic interference in PWM methods, particularly in multi-level converters, which require bulky filters and increase costs and instability.
Innovation Solution
The method employs a DC/ETAC power conversion system that distinguishes between energy effects and properties of AC quantities, using a variable envelope voltage to regulate power in AC networks, reducing switching losses and simplifying circuit structures by dividing the envelope voltage into specific ranges for efficient conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If multi-level converter structures are used to reduce switching losses and electromagnetic interference, then electromagnetic compatibility improves, but device complexity and cost increase due to multiple switches and cascaded substructures
Solution Approach 1:
The patent segments the voltage regulation function into two distinct components: envelope voltage regulation (affecting active power) and transition voltage regulation (affecting reactive power and waveform). This segmentation allows each component to be optimized independently, reducing overall system complexity while maintaining electromagnetic compatibility benefits
Solution Approach 2:
The patent introduces an intermediary classification system that distinguishes between envelope voltage effects (energy transfer) and transition voltage effects (waveform shaping). This intermediary framework enables selective application of regulation techniques, avoiding the need for complex multi-level structures while achieving similar electromagnetic compatibility performance
2Measurement precision
If PWM switching frequency is increased to improve power regulation precision, then power regulation precision improves, but switching losses increase due to dynamic limits of semiconductors
Solution Approach 1:
The patent segments the power regulation function into envelope voltage control (for active power and overall power level) and transition voltage control (for reactive power and fine-tuning). This segmentation allows lower switching frequencies to be used while maintaining precision, as each segment operates independently with optimized switching requirements
Solution Approach 2:
The patent changes the approach from high-frequency PWM switching to a dual-voltage-component method where precision is achieved through coordinated control of envelope and transition voltages. This parameter change fundamentally alters the switching frequency requirements, reducing energy losses while maintaining regulation precision
3Loss of energy
If switching times are reduced to decrease energy losses, then energy efficiency improves, but electromagnetic interference increases requiring bulky filters
Solution Approach 1:
The patent segments the voltage waveform into envelope and transition components, allowing the envelope component to handle energy transfer at lower frequencies (reducing losses) while the transition component manages waveform shaping and electromagnetic compatibility. This segmentation eliminates the need for bulky filters by addressing EMI at its source through structured voltage control
4Device complexity
If conventional diode type controlled switching is used, then device simplicity is maintained, but power regulation capability is limited compared to forced switching PWM methods
Solution Approach 1:
The patent segments the switching control into two independent systems: one for envelope voltage (providing basic power regulation with simple controlled diodes) and one for transition voltage (providing enhanced regulation capability). This segmentation preserves device simplicity while achieving advanced power regulation versatility through coordinated control of both segments
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The method can be used for the regulation of power in an alternating current electrical network (ACNW; ACNW1,ACNW2), using a conversion system (PCS) having at least two terminals (1,2; 1,2,3; 1,2,3,N) for connection to the network, wherein each of said terminals has a corresponding electrical potential. Each of the potentials of these terminals has an upper and a lower envelope, the difference between which, or envelope voltage (VEP,EN), is a variable positive continuous quantity having a maximum value (VEA) called the envelope amplitude. The method comprises the operations of: defining at least an upper range (ER) of voltage values, comprising said maximum value or envelope amplitude (VEA) and having a width (VE; VEE) which is substantially smaller than the envelope amplitude (VEA); using a structure (PCS) including at least a first static converter (ES) capable of regulating the electrical power by the regulation of the envelope voltage (VE; VEE) in the aforesaid upper range (ER); this upper range (ER) having a width determined in such a way that the at least one static converter (ES) regulates more than one half of the mean active electrical power exchanged with the network (ACNW; ACNW1, ACNW2).