A three-phase, heterofrequency capacitance and inductance tester has been developed.

发布时间：2022-11-25

To reduce reactive power losses, power supply systems typically employ shunt capacitor banks to improve the power factor. In practical applications, capacitor compensation devices exhibit a very high failure rate, which is determined by the operational characteristics of these systems.

A three-phase, heterofrequency capacitance‑inductance tester has been developed, employing high‑precision, large‑opening clamp‑on current and voltage transformers for current measurement. Utilizing a heterofrequency anti‑interference power supply, it delivers high measurement accuracy and stable data, with strong immunity to electromagnetic interference. It can perform tests in magnetic field environments without significant loss of accuracy, making it a specialized instrument for testing compensation capacitors. In addition to measuring single‑phase capacitors, the device also supports three‑phase capacitor testing, enabling one‑button measurement of three‑phase capacitor banks configured in various connection schemes—simple and practical. Furthermore, the instrument can measure a variety of series reactors and resistors, and it is capable of conducting standalone current measurements as well.

The inductance measurement device for series reactors features a small workload, ease of use, stable performance, high measurement accuracy, and a high rate of diagnosing common faults. Its current‑measurement module can also be used to measure equipment such as CVTs and high‑voltage surge arresters, offering multi‑functionality in a single instrument.

Operating Tips for the Automatic Capacitance and Inductance Tester:

1. Experimental operating voltage: When the characteristic impedance of the test specimen is not well known, a preliminary 2 V measurement can be performed; if the test current remains below 1 A, the voltage can be increased to 30 V for measurement.

2. Current measurement: Use the clamp‑on CT to clamp the circuit section where the current is to be measured. For example, you can clamp the conductor connected to a capacitor, rather than the capacitor’s waterproof terminal housing. If measuring the total current, you can directly clamp the line carrying the operating voltage.

3. Clamp‑on CT housing orientation: Position the clamp so that its front face is aligned with the red terminal (2 V or 20 V). At this point, the instrument automatically distinguishes between capacitance, inductance, and resistance.

4. Magnetic field effects: It is recommended to position the clamp‑type CT approximately 1 meter away from the instrument. If measuring an inductor with significant leakage flux, it is advisable to maintain a distance of about 1 meter from the inductor.

Indicators of the automatic capacitance and inductance tester:

1. Capacitance Measurement Range and Accuracy

Capacitance measurement range: 0.1 μF to 3500 μF

Capacitance measurement accuracy: ±(Reading × 1% + 0.005 μF)

Screen resolution: 0.001 μF (four significant digits)

2. Measurement Range and Accuracy of Inductors and Resistors

Inductor measurement range: 100 μH to 20 H

Resistor measurement range: 10 mΩ to 20 kΩ

Measurement accuracy: ±2% of the reading

3. Current Measurement Range and Accuracy

Current measurement range: AC 10 mA to 50 A, 30 to 150 Hz

Current measurement accuracy: ±1% of the reading