All-Current Sensitive Summation Current Transformer with Dual Cores
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Solution Overview
Problem
Electromechanical protective switching devices, such as residual current circuit breakers, face challenges in compact design and increased functionality within limited space, requiring improved current-sensitive summation current transformers for detecting differential currents effectively while minimizing installation space and costs.
Innovation Solution
A universal current-sensitive summation current transformer with a two-part housing and dual magnetic cores for alternating and direct current detection, using metal pins for direct connection to a printed circuit board, enabling a compact design and automated assembly process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a summation current transformer with dual magnetic cores is used to detect both AC and DC differential currents, then the functionality and reliability of the protective device is improved, but the device size and installation space requirements increase
Solution Approach 1:
The patent combines two separate magnetic cores (one for AC detection, one for DC detection) into a single integrated summation current transformer assembly. The cores are positioned concentrically with shared windings, allowing both AC and DC differential current detection functions to be merged into one compact device that installs in a single electrical box, thereby maintaining full functionality while reducing the number of separate components required.
Solution Approach 2:
The patent implements a nested structure where the first magnetic core and second magnetic core are positioned concentrically, with one core nested within or adjacent to the other. The windings are also nested, with the first secondary conductor wound around the first magnetic core and the second secondary conductor wound around the second magnetic core. This nesting arrangement maximizes space utilization and minimizes the overall volume of the transformer assembly.
2Ease of manufacture
If traditional assembly methods are used for assembling the summation current transformer, then manufacturing flexibility is maintained, but assembly time and production costs increase
Solution Approach 1:
The patent incorporates preliminary action by providing a mounting structure with pre-formed receiving spaces and connection terminals that are prepared in advance. The magnetic cores and windings are pre-assembled into modular units that can be quickly installed by simply placing them into the pre-prepared mounting structure and making electrical connections to the pre-positioned terminals, eliminating the need for complex on-site assembly operations.
Solution Approach 2:
The patent divides the summation current transformer into segmented modular components: the first magnetic core with its winding, the second magnetic core with its winding, and the mounting structure. This segmentation allows each module to be manufactured and tested independently, then assembled together in a standardized manner, improving both manufacturing flexibility and assembly efficiency.
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
The solution allows for a more compact and cost-effective design of the protective switching device, reducing installation complexity and improving the reliability of connections, thus enhancing the detection of differential currents within limited space.
Implementation Method 1
a first magnetic core (20) surrounding the through-opening (13) for detecting alternating fault currents
Implementation Method 2
a second magnetic core (30) surrounding the through-opening (13) for detecting DC fault currents
Implementation Method 3
all-current-sensitive summation current transformer... for detecting an electrical differential current
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
An all-current sensitive summation current transformer (1) for detecting a differential current is provided for an all-current sensitive residual current circuit breaker and has a two-part housing (10). The housing (10) has a through-opening (13) which is intended to accommodate at least two primary conductors (9) to be monitored with respect to the differential current. The summation current transformer (1) has a first magnetic core (20) surrounding the through-opening (13) for detecting alternating fault currents, which is wound with a first sensor winding (21) and held in a first housing part (11), and a second magnetic core (30) surrounding the through-opening (13) for detecting direct fault currents, which is wound with a second sensor winding (31) and held in a second housing part (12). The two magnetic cores (20, 30) are arranged one above the other.The summation current transformer (1) has several metal pins (40) which protrude beyond an outer contour of the housing (10). The first sensor winding (21) and the second sensor winding (31) each have two ends which are electrically connected to one of the metal pins (40) that are designed for electrical contact with a printed circuit board (100).