The dielectric loss tester is a precision instrument specifically used to measure the dielectric loss factor (usually expressed as tanδ, i.e., the tangent of the dielectric loss angle) and capacitance value (Cx) of insulating materials of electrical equipment under AC voltage. This test is very important for evaluating the insulation condition of power equipment, especially in the maintenance and preventive testing of power plants, substations, and other high-voltage power facilities.
Working Principle
The working principle of the dielectric loss tester is based on the following:
Standard circuit and test circuit: The instrument contains a highly stable standard capacitor (standard circuit) and a device under test (test circuit).
Variable frequency voltage regulation power supply: Generates AC voltage with variable frequency, generally using 45Hz or 55Hz, 55Hz or 65Hz, to avoid power frequency interference.
Vector calculation: By measuring the current amplitude and phase difference of the standard circuit and the test circuit, vector calculation is used to determine the capacitance value and dielectric loss tangent of the test object.
Data processing: Uses microcontroller and electronic technology for data calculation, digital real-time acquisition and processing of measurement data.
Anti-interference capability
In order to ensure measurement accuracy in complex electromagnetic environments, modern dielectric loss testers have strong anti-interference capability and can eliminate power frequency electric field interference, mainly due to their frequency conversion technology and digital signal processing technology.
Application Scope
Dielectric loss testers are widely used in:
Measuring the dielectric loss and capacitance of various high-voltage power equipment, such as power cables, capacitors, transformers, and instrument transformers.
On-site testing using generator power supply during complete power outages.
Measuring the dielectric loss of insulating oil by equipping with a special insulating oil cup.
Features
Integrated design: Integrates the test bridge, power supply, step-up transformer, and standard capacitor.
Intelligent operation: Uses advanced electronic technology to provide automated testing process and data processing.
Portability: Compact design, easy to carry to the site for testing.
Usage Scenarios
Preventive testing: In the regular maintenance of electrical equipment, used to evaluate insulation condition and prevent possible faults.
Fault diagnosis: When electrical equipment is abnormal, used for in-depth analysis of the health status of insulating materials.
The dielectric loss tester is an indispensable testing tool in the power industry, helping engineers and technicians ensure the safe operation of power systems.
