Multi-Winding Transformer for Double-Circuit Line Series Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing series compensation devices for power grids with double-circuit lines require multiple series transformers, increasing area occupation, investment costs, and equipment losses, limiting their application due to the need for two series transformers for each circuit line.
Innovation Solution
A series compensation device comprising a single three-phase multi-winding transformer with at least two windings connected in series to double-circuit lines, where the windings are connected to a voltage source converter, and additional devices like circuit breakers and arresters can be included for enhanced functionality, allowing for reduced converter current capacity and cost-effective operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two series transformers are used to connect series compensation devices to double-circuit lines, then the connection reliability is improved, but the area occupation, investment costs, and equipment losses increase
Solution Approach 1:
The patent merges two separate series transformers into a single three-phase multi-winding transformer. The transformer has a primary winding connected to the power grid and secondary windings connected to both circuit lines, thereby combining the functions of two transformers into one device that reduces area occupation while maintaining connection reliability
Solution Approach 2:
The three-phase multi-winding transformer serves multiple functions simultaneously: it provides series compensation for both circuit lines, acts as an isolation transformer, and enables flexible connection configurations. This multi-functional design eliminates the need for separate transformers for each circuit line
2Reliability
If two series transformers are used to connect series compensation devices to double-circuit lines, then the connection reliability is improved, but the investment costs increase
Solution Approach 1:
By combining two series transformers into one multi-winding transformer, the patent reduces the total number of expensive transformer units required, thereby lowering investment costs while maintaining the same level of connection reliability through the transformer's multiple windings
3Reliability
If two series transformers are used to connect series compensation devices to double-circuit lines, then the connection reliability is improved, but the equipment losses increase
Solution Approach 1:
The patent reduces equipment losses by merging two transformers into one, eliminating redundant magnetic circuits and reducing total copper and iron losses. The single multi-winding transformer has lower overall losses compared to two separate transformers while providing the same series compensation function for both circuit lines
4Area of stationary object
If a single series transformer is used to connect series compensation devices to double-circuit lines, then the area occupation and investment costs are reduced, but the device complexity increases
Solution Approach 1:
The three-phase multi-winding transformer is designed with multiple secondary windings that can be independently connected to different circuit lines. This universal design allows a single transformer structure to handle multiple functions and configurations, managing complexity through standardized multi-functional architecture
5Ease of manufacture
If a single series transformer is used to connect series compensation devices to double-circuit lines, then the investment costs are reduced, but the converter capacity requirements increase
Solution Approach 1:
The patent segments the transformer's secondary windings to connect to different circuit lines independently, allowing the voltage source converter to share its capacity across multiple lines. This segmentation enables more efficient utilization of converter capacity compared to having dedicated converters for each circuit line
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 configuration reduces the converter capacity and cost, saves area, and improves the reliability and economy of Flexible AC Transmission Systems (FACTS) connected to power grids by using a single series transformer to manage double-circuit lines efficiently.
Implementation Method 1
one three-phase multi-winding transformer, wherein at least two windings of the three-phase multi-winding transformer are connected in series into the double-circuit lines respectively, and at least one winding is connected to an AC side of the voltage source converter
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
A series compensation device suitable to double-circuit lines is disclosed. The device includes one series transformer and one converter. One converter and dual-circuit transmission lines are respectively connected to three windings of one series transformer. In the solution provided in the present application, the device can be independently installed in a power transmission system to be used as a static synchronous series compensator, and can also be used as a component of a unified power flow controller, a convertible static compensator, an interline power flow controller and a unified power quality conditioner to be connected to a power transmission system device in series. The device can save the capacity of a converter, improve the application efficiency of the series compensation device, and reduce the cost and area occupation.