Introduction

A power conditioner supplies the power (outputs the current) to the grid by using the voltage difference between grid voltage and output voltage. Also, it constantly monitors the grid voltage and frequency so that it can adjust the output voltage and frequency as required.

Problem

• Inverter controlled equipment stops because it detects a fault on the commercial power supply
• Malfunction of peripheral equipment
• Power cannot be sold back to the utility company due to voltage fluctuation of the commercial power supply (especially when the voltage increases).  Due to fluctuation of neighboring load conditions, the voltage of the commercial power supply fluctuates, causing the safety system of the power conditioner to prevent the selling of the power.

Analysis

The following items should be measured simultaneously:

• Voltage fluctuation
• Frequency fluctuation – Model PW3198 can measure the 10s average frequency required for Class A classification of the IEC61000-4-30 standard. In addition, the PQA can measure the average frequency of 200ms aggregation and 1 cycle frequency. By using these additional capabilities, it helps to confirm the stability of the output frequency from a power conditioner.
• Transient overvoltage, Waveform distortion – This is often generated by lightning strikes, switching from generation to consumption, grid switching, etc. It causes malfunction in equipment and solar power generation system, etc.
• Inrush current
• Harmonics (Both voltage and current)
• High-order harmonics
• Flicker

Also, power and integrated power (consumption, re-generation) can be measured simultaneously with the power quality parameters.

Source : Guidebook for Power Quality Measurement, HIOKI E.E. Corporation