A New Locating Method of Break Faults in an Active Distribution Network Based on Distributed Generator Monitoring

Abstract

Traditional distribution networks are transforming into active distribution networks (ADNs) with the advancement of distributed generators (DGs). Break faults that lead to voltage and current imbalances and fluctuations threat the safety of sensitive power electronic equipment in ADNs. However, locating break faults in ADNs remains a challenge under the influence of DG fault polymorphism. This paper proposes a new method to locate break faults by monitoring information of DG current based on the observability of ADNs. The DG equivalent model is established based on the DG output characteristics under the presence of a single-phase break fault. The characteristics of the fault current contributed by DG are analyzed. An identification method of break faults is proposed based on the variations in DG current. Thus, a fault-locating matrix algorithm is proposed combined with current information and location information of DGs. The simulation results demonstrate that the proposed method can locate break faults quickly and accurately. The method is not affected by topology and changes of DG output and load.

A Section Location Method of Single-Phase Short-Circuit Faults for Distribution Networks Containing Distributed Generators Based on Fusion Fault Confidence of Short-Circuit Current Vectors

“…When the fault point is located between D can be seen from Equations ( 6) and ( 8) that the current upstream of the fault point short-circuit current of the superior grid and DG1, and the current downstream fault point is the short-circuit current provided by the DGs downstream of the fault Due to the short-circuit current of the superior grid, the current magnitude upstre the fault point is also much larger than the current magnitude downstream, as sho Figure 2. When the fault point is located between a DG and the load, because th impedance is much larger than the line impedance [31], the current flowing downs of the fault point is much smaller than the short-circuit current measured upstream fault point. Whether a single-phase short-circuit fault occurs between the bus and a DG, between DGs, or between a DG and the load due to the difference between the short-circuit current of DGs and synchronous generators, there is a phenomenon of limited magnitude.…”

“…Due to the short-circuit current of the superior grid, the current magnitude upstream of the fault point is also much larger than the current magnitude downstream, as shown in Figure 2. When the fault point is located between a DG and the load, because the load impedance is much larger than the line impedance [31], the current flowing downstream of the fault point is much smaller than the short-circuit current measured upstream of the fault point.…”