Three-Phase Voltage Sensor for Asymmetrical Drop Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical apparatuses with grid interconnection functions experience large deviations in determining voltage drop amplitude during asymmetrical phase drops, lacking a low voltage ride-through function.
Innovation Solution
A method and device that detect the first voltage for each phase in a three-phase alternating current, acquire the drop amplitude, and perform reactive power compensation, using virtualized phase voltages to ensure accurate amplitude determination and control grid interconnection based on stored voltage angles during voltage drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional inverter control is used with line voltage collection, then the device structure is simple, but the voltage drop amplitude determination has large deviation during asymmetrical phase drops
Solution Approach 1:
The patent introduces a three-phase voltage sensor as an intermediary measurement device to accurately capture phase voltages during asymmetrical drops. This sensor acts as a mediator between the power grid and the control system, providing precise voltage data that enables accurate drop amplitude determination without requiring complex control algorithms
Solution Approach 2:
The patent implements preliminary detection of phase voltages using the three-phase voltage sensor before asymmetrical drops occur. By continuously monitoring and storing voltage data in advance, the system prepares accurate baseline measurements that enable precise drop amplitude calculation when asymmetrical drops happen, eliminating the need for complex real-time analysis during the drop event
2Reliability
If reactive power compensation is performed during voltage drops, then the low voltage ride-through function is improved, but the control complexity increases
Solution Approach 1:
The patent implements a feedback control mechanism where the detected phase voltage drop amplitude is fed back to the control system, which then adjusts the reactive power compensation accordingly. This closed-loop feedback enables the system to automatically maintain reliable operation during voltage drops by continuously monitoring voltage conditions and adjusting compensation in real-time
Solution Approach 2:
The patent changes the operating parameter of reactive power compensation based on the detected voltage drop amplitude. By dynamically adjusting the reactive power injection level according to the severity of the voltage drop, the system achieves reliable low voltage ride-through while using a relatively simple control approach that scales compensation with disturbance severity
Data Source
AI summary
Disclosed are a method and device for processing a voltage drop, a grid interconnection method and device for processing an electrical apparatus, and a system. The method includes: acquiring a drop amplitude of a first voltage for each phase in a three-phase alternating current (S204); and under a condition in which the first voltage for any phase in the three-phase alternating current drops, performing reactive power compensation according to a drop amplitude of the first voltage for a phase in which the first voltage drops (S206). Therefore, the electrical apparatus has a low voltage ride-through function, thereby solving the technical problem of a large deviation of voltage drop amplitude determination arising from an asymmetrical drop of three phases.