The instruments and equipment used in power engineering testing are diverse in types. According to their functions and application scenarios, they can be classified into five major categories, each of which includes typical instruments and core application scenarios.
1. Insulation and Electrical Test Category
This category of equipment is mainly used to evaluate the insulation performance and electrical strength of power equipment.
Insulation Resistance Tester: Measures the insulation resistance of equipment such as motors, cables, and transformers, and determines the overall insulation condition of the equipment due to moisture or aging.
High Voltage Generator, No-Discharge Test Transformer: Applies high voltage to the equipment to conduct power frequency withstand tests and assess the insulation strength of the equipment.
Dielectric Loss Tester: Measures the dielectric loss angle tangent value (tanδ) and capacitance of capacitive equipment such as current transformers and bushings, and sensitively identifies overall moisture and aging defects in insulation.
Oil Chromatography Analyzer: Analyzes the dissolved gases in transformer oil to determine whether there are overheating or discharge faults inside the transformer.
2. Power Quality Analysis Category
This category of equipment is mainly used to monitor and analyze power quality issues in the power grid.
Power Quality Analyzer: Records long-term steady-state parameters such as voltage deviation, frequency fluctuation, harmonic distortion rate, and three-phase imbalance degree, captures transient events such as voltage drops, surges, and transient pulses, and is used to assess whether the power quality meets national standards.
Power Analyzer: Precisely measures the efficiency of equipment such as frequency converters and motors, analyzes input and output power and energy loss.
High-Speed Oscilloscope: Captures rapid transient overvoltages and waveform distortions on the power grid at microsecond to nanosecond levels, assisting in analyzing interference sources.
3. Live Detection and Condition Monitoring Category
This category of equipment can conduct detection while the equipment is in operation, achieving early fault warning.
Infrared Thermography: Non-contact detection of temperature distribution on equipment surfaces, visually identifying defects such as overheating of electrical connections and internal heating of the equipment, and serving as a common tool for inspection.
Partial Discharge Detector: Detects internal partial discharge conditions of equipment such as switch cabinets, GIS (Gas Insulated Full Enclosed Combined Electrical Equipment), and cable joints through ultrasonic or ultra-high frequency sensors, and identifies early insulation hazards.
Ultraviolet Imaging: Detects corona discharge and surface discharge to observe the insulation discharge conditions of insulator strings, hardware, and other external insulation.
4. Grounding and Relay Protection Test Category
This category of equipment provides a guarantee for the safe operation of the power system and reliable fault removal.
Ground Resistance Tester: Measures the grounding resistance value of the grounding grid and the conductivity of the equipment grounding wire to ensure that fault currents can be safely discharged into the ground.
Relay Protection Calibration Instrument: Simulates power system faults such as short circuits and grounding, outputs precise voltage and current to the protection device, measures action time and action values, and verifies the accuracy of the protection device logic and setting values.
Special DC Power Supply Testing Equipment: Includes battery pack testers and DC circuit breaker testing systems, used to ensure the reliability of the DC system power supply and the selectivity of protection actions.
5. General and Safety Testing Category
This category of equipment is the basic tool for on-site testing work.
High-Precision Digital Multimeter, Clamp Meter: Conduct daily voltage, current, and resistance measurements, and troubleshoot simple faults.
Multifunction Calibration Source: Regularly calibrates other testing instruments to ensure measurement accuracy.
Non-Contact Insulation Testers: Essential safety tools before operating high-voltage equipment, confirming whether the equipment is de-energized.
Laser Distance Meter: Measures the safe distance of live equipment, and maps the positions and dimensions of on-site equipment.
Key Standard Explanation
The power quality analysis work should follow the new national standard GB/T 19862-2025 “General Requirements for Power Quality Monitoring Equipment”.
This standard was released on October 5, 2025, and officially implemented on February 1, 2026, replacing the old version standard in 2016. It makes new regulations on technical requirements and classification and grading of power quality monitoring equipment, and is the core basis for selecting and using power quality analyzers.
Post time: Mar-18-2026