Study on the Development of Measurement Technology for Direct Current Power Systems in Insulation State Using AHRD Algorithm

In this study, an algorithm was developed to represent the insulation state of uninterruptible direct current power supply systems, including circuitry. The existing insulation monitoring system in uninterruptible state was only possible with attachment type devices, but there was no portable inspection equipment at the site. This algorithm is called asymmetric high resistance detection (AHRD), which can compensate for the shortcomings of existing pulse and passive measurement methods, like not being able to measure when both positive and negative electrodes are poorly insulated. The researchers then developed a device that uses this algorithm for the on-site testing of direct current power supply systems, such as solar power generation units and energy storage systems (ESSs). Conversion and estimation formulas were also developed and verified by analyzing the correlation between the measurement values and simulation results of the device’s sensor parameter settings. A standard power supply and standard resistance were used on the newly developed insulation meter to assess it using a lab test and a performance test. Its performance is verified through a comparative analysis between the newly developed insulation meter with the existing insulation monitoring device at an ESS site. Applying the technology proposed in this study at testing sites can enable the verification of the insulation state of circuitry and direct current power supply systems, thereby preventing accidents by ensuring electrical safety.