GB/T 15945 specifies clear limits for the total harmonic voltage distortion rate of public power grids. During on-site troubleshooting, if only RMS values are measured, it is often difficult to locate the source of distortion. The SY-7500 Power Quality Analyzer is designed for operation and maintenance sites, integrating voltage/current measurement, power analysis, harmonic analysis, and transient event recording into a single portable device, with a measurement error of ≤±0.5%, enabling synchronous multi-parameter acquisition without interrupting power supply.
The traditional approach uses clamp current transformers to measure current, multimeters to measure voltage, and dedicated harmonic analyzers to analyze spectra. Multiple devices measure at different times, making it difficult to align phase and time references, and transient processes are easily missed. The SY-7500 uses a unified sampling clock, with three-phase voltage/current, power, power factor, THD, and unbalance refreshed on the same screen. Waveforms, spectra, and vector diagrams can be cross-referenced, reducing repetitive work caused by changing instrument connections.
During testing, acquisition is started and the instrument displays the above parameters in real time. If transient events need to be captured, the event recording function automatically records the complete waveform before and after the fault for later review. The device is suitable for power system operation and maintenance, fault diagnosis, energy efficiency assessment, and power quality management, and can also be used for secondary circuit verification of independent gas compartment bays such as substation busbars, voltage transformers, and surge arresters.
