Resonant AC Test System / AC Resonance Test System - Test Precautions?

The test precautions for the AC resonance test system are as follows:

I. Detailed Preparation Before the Test

1. Parameter Matching Calculation: Accurately estimate or measure the capacitance of the test specimen, calculate the expected resonant frequency, and rationally configure the reactor combination and taps to ensure that the system resonant point falls within the operating frequency range of the device. This is the foundation for a successful test.

2. System Inspection and Grounding: Check that the excitation transformer, reactors, voltage dividers, and other components are reliably connected and undamaged. The entire system must achieve reliable grounding at one point, and the grounding wire should have sufficient cross-sectional area to ensure safety and reduce interference.

3. Ensure Safe Distance: Ensure the high-voltage lead is securely connected and maintain a sufficient safe distance from other grounded bodies (such as equipment casing and structure).

II. Precise Control of the Test Process

1. Low Voltage Tuning: The frequency must be slowly adjusted under low excitation voltage (usually 10%-20% of the test voltage), closely observing the changes in output voltage and current. When the loop current reaches its maximum value and the test specimen voltage increases significantly, this is the resonant point. 1. It is strictly forbidden to locate the resonant point under high voltage.

2. Smooth Voltage Increase and Synchronous Monitoring: After finding the resonant point, maintain a stable frequency and smoothly increase the excitation voltage. Closely monitor key parameters such as the high-voltage side voltage, loop current, and frequency throughout the process.

3. Utilizing Characteristics and Handling Anomalies: During resonance, the test sample receives high voltage, but the power supply output current is relatively small. If flashover breakdown occurs on the test sample, the resonance condition disappears, and the loop current automatically decreases, providing natural current-limiting protection. However, it is still necessary to immediately and quickly reduce the voltage and disconnect the power supply.

III. Post-Test Procedures

• After the test is completed and the power is disconnected, a dedicated discharge rod must be used to fully and thoroughly discharge the test sample (especially large-capacity equipment such as cables and GIS). It is recommended to first discharge through a resistor and then directly short-circuit to ground.

Summary: The core of AC resonance testing lies in "precise matching, careful tuning, and smooth voltage increase." Strictly following the procedures of parameter calculation, low-voltage tuning, continuous monitoring, and safe discharge is fundamental to ensuring a safe, effective, and labor-saving test. The MSXB-F-270kVA 270kV AC Resonance Test System is primarily designed for AC withstand voltage tests of 35kV and 110kV cables, 110kV main transformers, GIS systems, and circuit breakers. It has a wide range of applications and is an ideal withstand voltage testing device for municipal, county, and prefecture-level high-voltage testing departments, as well as power installation and maintenance engineering units. The system mainly consists of a frequency converter, excitation transformer, reactor, capacitive voltage divider, and compensation capacitors.

1. 0.5km of 110kV/300mm² cable, capacitance ≤0.0735μF, test frequency 30-300Hz, test voltage 128kV, test time 60min

2. 2km of 35kV/300mm² cable, capacitance ≤0.389μF, test frequency 30-300Hz, test voltage 52kV, test time 60min

3. 5km of 10kV/300mm² cable, capacitance ≤1.88μF, test frequency 30-300Hz, test voltage 22kV, test time 60min

4. GIS, switchgear, and other substation equipment with voltage levels of 110kV and below, test frequency... 5. For 110kV/63000kVA main transformers, with a capacitance ≤0.02uF, the test frequency is 45-65Hz, the test voltage is 52kV, and the test time is 1min.

6. For GIS, switchgear, and other substation equipment with voltage levels of 35kV and below, the test frequency is 30-300Hz, the test voltage is 95kV, and the test time is 1min. (This last part is a list of terms related to AC resonance testing systems, including variable inductance AC resonance test systems and AC resonance test instruments.)