Phase Balancing Device for Three-Phase Current
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Solution Overview
Problem
Imbalances in three-phase currents between domestic and distribution networks can lead to overloading and transformer degradation due to unbalanced current consumption or injection, posing risks to both consumers and electricity suppliers.
Innovation Solution
A phase balancing method using a device with a first AC/DC converter and a second DC/AC converter, connected by their direct current terminals, along with a control unit and current measurement sensors, measures and adjusts the power differences across phases to achieve balanced current distribution by transforming differential currents into direct or alternating currents as needed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If current is injected or consumed on only one or two phases of a three-phase system, then the domestic network can operate with simpler connection configurations, but phase imbalances occur leading to overloading and transformer degradation
Solution Approach 1:
The patent introduces a phase balancing device as an intermediary component between the domestic network and the distribution network. This device includes AC/DC converters and DC/AC converters that actively measure current on each phase and inject compensating currents to balance the phases. The intermediary device enables simple single-phase or two-phase connections at the domestic level while maintaining three-phase balance at the distribution level, thus resolving the contradiction between connection simplicity and phase balance stability.
2Reliability
If phase balancing devices with multiple converters are deployed, then phase balance and network stability are improved, but device complexity and cost increase
Solution Approach 1:
The patent combines multiple converter functions into an integrated phase balancing device. The AC/DC converters and DC/AC converters are merged into a single system with shared control electronics and current measurement sensors. This consolidation reduces device complexity compared to having separate balancing devices for each phase, while maintaining the reliability benefits of active phase balancing.
3Manufacturing precision
If real-time current measurement and adjustment is implemented, then phase balancing precision is improved, but measurement and control complexity increase
Solution Approach 1:
The patent implements a feedback control system where current measurement sensors continuously monitor the current on each phase, the control electronics calculate the phase imbalances, and the converters inject compensating currents in real-time. This closed-loop feedback mechanism achieves high phase balancing precision while managing measurement complexity through automated control algorithms that process sensor data and adjust converter output dynamically.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively balances three-phase currents, preventing overloading and transformer overheating by ensuring equal current intensities across phases, thereby enhancing network stability and safety.
Implementation Method 1
draw from the respective phase conductor (2a, 2b, 2c) a differential current whose power corresponds to said difference using of the first AC/DC converter (5) and transforming said differential current using the first AC/DC converter (5) into a first direct current
Implementation Method 2
transforming the first direct current into alternating current using the second DC/AC converter (6) and applying this alternating current to the phase conductor (2a, 2b, 2c)
Data Source
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AI summary
The present invention relates to a method for balancing phases of a three-phase consumption current taken from a distribution grid and consumed by at least one consumer device installed in a home grid (1) or a three-phase injection current injected into the distribution grid and produced by at least one energy production device installed in the home grid (1), said consumption current and/or said injection current being conveyed in an electrical line (2) comprising at least three phase conductors (2a, 2b, 2c). This balancing method is implemented using a phase balancing device comprising a first AC/DC converter (5) and a second DC/AC converter (6) connected by their DC terminals (8, 9), and in addition a control unit (10).