Power Converter Control Without Galvanic Isolation Ground Current
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Solution Overview
Problem
There is a need for an efficient operating method for a power converter arrangement that includes a first converter and a second converter, where the second power converter lacks galvanic isolation, while maintaining efficient operation and preventing current flow between the load and ground.
Innovation Solution
The method involves operating the power converter arrangement in a first operating mode where the input power received by the first power converter is adjusted based on output and ground signals, and the first and second intermediate voltages are adjusted by the second power converter to track maximum and minimum switched node voltage references, respectively, without the need for galvanic isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If galvanic isolation is implemented using a transformer in the second power converter, then safety and electrical isolation are improved, but cost and device size increase significantly
Solution Approach 1:
The patent removes the transformer (galvanic isolation component) from the second power converter, extracting only the essential function of electrical isolation while eliminating the bulky transformer component. This is achieved through a control method that prevents ground current flow without requiring physical galvanic isolation hardware.
Solution Approach 2:
The patent replaces the mechanical/electromagnetic isolation mechanism (transformer) with an electronic control mechanism. The control circuit monitors ground current and dynamically adjusts switching signals to prevent harmful current flow, substituting physical isolation with intelligent electronic control.
2Adaptability or versatility
If all converter stages are operated in switched-mode with electronic switches, then power conversion flexibility is improved, but power consumption and switching losses increase
Solution Approach 1:
The patent implements dynamic operation mode selection for converter stages based on real-time operating conditions. The control circuit can switch between switched-mode operation (high flexibility) and non-switched-mode operation (low losses) for different converter stages, optimizing the balance between flexibility and efficiency.
Solution Approach 2:
The patent applies switched-mode operation only to the extent necessary for maintaining power conversion flexibility, while allowing other converter stages to operate in more efficient non-switched modes. This partial application of switching reduces overall switching losses while maintaining adequate system flexibility.
Data Source
AI summary
A method for operating a power converter arrangement, a controller for controlling operation of a power converter arrangement, and a power converter arrangement are disclosed. The method includes operating a power converter arrangement in a first operating mode. The power converter arrangement includes: a first power converter (1) comprising input nodes (a, b, c) each configured to receive a respective one of input voltages (Va, Vb, Vc) each referenced to a first ground node (n), and configured to provide first and second intermediate voltages (Vx, Vz) each referenced to a second ground node (y); and a second power converter connected between the first power converter (1) and an output (p, r) of the power converter arrangement.