Inverter Voltage Control With Parallel Voltage and Current Loops
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Solution Overview
Problem
The existing voltage control methods for inverters, which connect an outer voltage loop and an inner current loop in series, face complexity in parameter design and limited bandwidth, affecting system stability and response speed.
Innovation Solution
A voltage control method where the voltage loop and double current loops run in parallel, with the current loop dynamically limiting the amplitude of the voltage loop, allowing separate design of loop parameters and improving response speed and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the voltage loop and current loop are connected in series, then dual control on voltage and current is implemented, but parameter design becomes complex and system stability is affected
Solution Approach 1:
The patent divides the control system into independent voltage loop and current loop modules that operate in parallel rather than series. Each loop has its own independent parameter design, eliminating the coupling complexity while maintaining dual control functionality through separate control paths.
2Adaptability or versatility
If the voltage loop and current loop are connected in series, then dual control is achieved, but bandwidth of the voltage loop is limited and response speed is affected
Solution Approach 1:
By segmenting the control loops to run in parallel, each loop can operate at its optimal bandwidth without being constrained by the other. The voltage loop and current loop are independent, allowing the voltage loop to achieve higher bandwidth and faster response speed while still providing dual control through separate control channels.
3Adaptability or versatility
If the voltage loop and current loop are connected in series, then dual control is implemented, but the two loops affect each other making parameter design complex
Solution Approach 1:
The patent segments the control architecture into independent parallel loops, eliminating the mutual interference that occurs in series connections. Each loop can be designed and tuned independently, improving system stability by removing coupling effects while maintaining dual control capability through separate control paths.
Solution Approach 2:
Instead of connecting loops in series where output of one becomes input of the other, the patent inverts the architecture to parallel connection where both loops operate independently on the same system, fundamentally changing the control topology to eliminate stability issues caused by loop interaction.
Data Source
AI summary
A voltage source inverter includes a bus capacitor, a bidirectional power tube, a filter inductor, and a filter capacitor. A voltage control method includes: respectively obtaining a first feedback current and a first feedback voltage from an output end of the filter inductor and an output end of the filter capacitor; obtaining a first duty cycle and a second duty cycle based on the first feedback current, a maximum current reference value, and a minimum current reference value in a current loop; obtaining a third duty cycle based on the first feedback voltage and a voltage reference value in a voltage loop; and selecting one of the first duty cycle, the second duty cycle, and the third duty cycle, and controlling the bidirectional power tube, so that a duty cycle of the bidirectional power tube is between the first duty cycle and the second duty cycle.