Wireless Current Measurement Device for Hybrid Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current measurement devices struggle to measure both direct current (DC) and alternating current (AC) efficiently and in a compact form, especially in small spaces, and are limited in flexibility and accuracy when dealing with hybrid vehicles and electric vehicles.
Innovation Solution
A current measurement device comprising a first sensor for detecting DC and low-frequency AC magnetic fields, a second sensor for detecting AC fields from low to high frequencies, and a synthesizer to combine the results, allowing for wireless measurement of currents up to several tens of megahertz, with a fixing mechanism to set the sensor distance and triaxial sensors for noise cancellation and precise distance calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single current measurement device is used to measure both DC and AC currents, then versatility is improved, but measurement precision deteriorates
Solution Approach 1:
The current measurement device is segmented into two separate measurement paths: one for DC/low-frequency AC measurement using a magnetic sensor, and another for high-frequency AC measurement using a Rogowski coil. Each path is optimized for its specific frequency range, allowing the device to maintain high measurement precision for both DC and AC currents simultaneously
Solution Approach 2:
The device integrates multiple measurement functions into a single system by combining DC/low-frequency AC measurement capabilities with high-frequency AC measurement capabilities. The synthesis unit combines results from both measurement paths to provide universal current measurement coverage from DC to high-frequency AC
2Volume of moving object
If the current measurement device is made small in size, then ease of installation is improved, but measurement precision deteriorates
Solution Approach 1:
The device employs a nested structure where the Rogowski coil is positioned around the magnetic sensor assembly. This nesting allows both measurement components to be compactly arranged in a small volume while maintaining their respective measurement capabilities and precision
Solution Approach 2:
The measurement functionality is extended from a single spatial dimension to multiple dimensions by combining measurements from different sensor orientations and measurement principles, enabling accurate current measurement in a compact three-dimensional package
3Ease of operation
If wireless measurement is implemented, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The device replaces complex mechanical coupling and physical connections with wireless measurement technology. Magnetic sensors and Rogowski coils detect current through magnetic field coupling without mechanical contact, simplifying installation and operation while reducing system complexity through contactless measurement
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
Enables accurate and flexible wireless measurement of both DC and AC currents in a small size, suitable for installation in limited spaces, improving measurement accuracy and flexibility, particularly in hybrid and electric vehicles.
Implementation Method 1
a first sensor SE1 configured to detect a direct current (DC) magnetic field and a low-frequency alternating current (AC) magnetic field generated due to the current flowing through the conductor to be measured
Implementation Method 2
a second sensor SE2 configured to detect alternating current magnetic fields from a low frequency to a high frequency generated due to the current flowing through the conductor to be measured
Implementation Method 3
the Rogowski type current measurement device measures a current flowing through a conductor to be measured by providing a Rogowski coil (an air-core coil) near the conductor to be measured and detecting a voltage induced in the Rogowski coil when a magnetic field generated by an alternating current (AC) flowing through the conductor to be measured crosses the Rogowski coil
Data Source
AI summary
The current measurement device (1, 2) includes a first sensor (SE1) configured to detect a direct current magnetic field and a low-frequency alternating current magnetic field generated due to the current (1) flowing through the conductor (MC) to be measured, a second sensor (SE2) configured to detect alternating current magnetic fields from a low frequency to a high frequency generated due to the current (I) flowing through the conductor to be measured, a first calculator (21, 21A) configured to calculate the current flowing through the conductor to be measured from a detection result of the first sensor using distance information indicating a distance (r) between the first sensor (SE1) and the conductor (MC) to be measured, a second calculator (22) configured to calculate the current flowing through the conductor to be measured from a detection result of the second sensor, and a synthesizer (23) configured to synthesize a calculation result of the first calculator with a calculation result of the second calculator.