Capacitance and inductance testers, such as clamp-type current transformers



Capacitance and inductance testers are specialized instruments used in power systems to detect reactive power compensation devices (such as shunt capacitor banks and reactors). Their core value lies in solving the problem of accurately measuring the capacitance of individual capacitors without disconnecting the connecting wires during on-site measurements at substations, greatly improving maintenance efficiency and safety.

Based on different application scenarios and technical principles, these instruments are mainly divided into two categories:

⚡ Specialized for Power Systems: Experts in Non-Disconnective Measurement

These instruments are specifically designed for on-site operation and maintenance in substations and distribution networks, and are common tools for preventive testing of power systems.

Core Pain Point Solution: Traditional methods for measuring individual capacitors in shunt capacitor banks require disconnecting the busbar connecting wires one by one, which is labor-intensive and can easily damage equipment. Specialized testers for power systems achieve non-disconnective measurement through unique circuit design and measurement methods.

Working Principle:

Heterodyne Anti-Interference: The instrument internally synthesizes a test signal different from the power frequency (50Hz), such as 40Hz-70Hz, and applies it to the device under test. This effectively avoids strong on-site power frequency electromagnetic field interference, ensuring measurement accuracy.

Synchronous Sampling: Using a bridge circuit or similar principles, voltage sensors and current sensors (such as clamp-type current transformers) synchronously collect signals from standard components and the test object, and the built-in processor calculates capacitance and inductance values.

Main Features:

Functional Integration: Not only can it measure capacitance (C) and inductance (L), but also resistance (R), current, voltage, impedance, phase angle, and other parameters. Some models can also serve as CVT and arrester testers.

High Automation: Equipped with automatic range switching, three-phase unbalance rate calculation, data storage, and printing functions.

Portable Design: Mostly portable or handheld, with built-in large-capacity lithium batteries, suitable for outdoor use without power supply.

Typical Applications:

Measure the capacitance of individual capacitors in high-voltage shunt capacitor banks to determine if they are damaged or have capacity degradation.

Measure the inductance of various reactors.

Perform fault diagnosis and preventive testing of reactive power compensation devices.