Self-Powered Wireless Current Transformer for Load Center Monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Large and complex load centers face challenges in managing circuit branches due to the difficulty in physically placing Current Transformers (CTs) and corresponding circuitry, which complicates installation, expansion, and maintenance, while also posing safety and regulatory compliance issues.
Innovation Solution
A self-powered, wireless CT system that includes a Current Transformer (CT) module and a communication module, where the CT module generates a reference signal and stores energy to power a microcontroller for current measurement, and the communication module measures voltage, phase, and frequency, transmitting this information wirelessly to calculate power levels, reducing the need for internal power supplies and simplifying the system's design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional CT systems with internal power supplies are used in load centers, then current monitoring capability is achieved, but device complexity and installation difficulty increase due to the need for power supply wiring and compliance with electrical codes
Solution Approach 1:
The CT module harvests power from the current it monitors using a capacitor connected in parallel with the CT secondary winding. The capacitor accumulates energy from the CT output and provides power to the microcontroller and communication module, making the device self-powered and eliminating the need for separate power supply wiring and electrical code compliance
Solution Approach 2:
The power supply function is extracted from the CT module by using the capacitor to store energy from the CT output. This separates the power generation function (CT) from the power consumption function (microcontroller and communication module), allowing the monitoring device to operate without external power wiring
2Adaptability or versatility
If multiple CT modules are installed in a load center, then monitoring coverage is improved, but physical placement and maintenance difficulty increase
Solution Approach 1:
The mechanical wiring system is replaced with wireless communication. The microcontroller communicates current measurements and device status wirelessly to external systems, eliminating the need for complex wiring connections and making installation and maintenance simpler while allowing flexible placement of multiple CT modules throughout the load center
3Ease of operation
If wireless communication is added to CT modules, then system expansion and maintenance ease are improved, but energy consumption increases
Solution Approach 1:
The communication module transmits data periodically rather than continuously, allowing the capacitor to recharge between transmission events. This periodic operation reduces average power consumption while maintaining wireless communication capability for system expansion and remote monitoring
Solution Approach 2:
The system changes operational parameters dynamically - the microcontroller adjusts its activity level and communication frequency based on available energy in the capacitor, optimizing the balance between wireless communication functionality and energy consumption from the harvested power
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 system provides a compact, manageable, and safe method for monitoring load center circuit branches, reducing complexity and compliance issues by eliminating the need for internal power supplies and enabling efficient energy management through wireless communication.
Implementation Method 1
a Current Transformer (CT) configured to be coupled to the at least one circuit branch and to produce a reference signal having a level related to a current level of the at least one circuit branch
Implementation Method 2
a capacitor coupled to the rectifier, wherein, the capacitor is configured to store energy from the rectified reference signal
Data Source
Figure 1
Figure 2
Figure 3
AI summary
According to one aspect, embodiments of the invention provide a system for monitoring at least one circuit branch coupled to a power line, the system comprising at least one first module comprising a Current Transformer (CT) configured to be coupled to the at least one circuit branch and to produce a reference signal having a level related to a current level of the at least one circuit branch, a rectifier coupled to the CT and configured to produce a rectified reference signal, a capacitor coupled to the rectifier, and a first microcontroller coupled to the capacitor and the rectifier, wherein, the capacitor is configured to store energy from the rectified reference signal, and wherein, the first microcontroller is configured to be powered by the energy stored in the capacitor and to sample the rectified reference signal to determine the current level of the at least one circuit branch.