# Fault Diagnosis System of Power Grid Based on Multi-Data Sources
## 4 Fault Tracking Quasi-Real-Time Processing System and Fault Diagnosis Batch Processing System
### Implementation of Fault Tracking Quasi-Real-Time Processing System
#### 4.1.2 Fault Reason Tracking Considering Partial Information Loss  
In reference [13], the Bayesian network algorithm for fault tracking of relay protection devices is given. Considering the loss of partial warning-level information, the algorithm is improved in this article. Table 5 can be seen as the adjacency matrix \(M\)(\(R\),\(S\)) between the fault reasons and features. \(M\)(\(R\),\(S\)) is a sparse matrix with a large number of elements of 0. After \(M\)(\(R\),\(S\)) is \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Number** & **Fault Reason** & **Prior Probability** & **Number** & **Fault Feature** \\ \hline r1 & Operating power failure & 3.21\% & f1 & Abnormal voltage at two ends of tripping/closing coil \\ r2 & Secondary circuit poor contact & 8.84\% & f2 & Undersize current RMS of tripping/closing coil \\ r3 & Short circuit of tripping/closing coil & 4.57 & f3 & Oversize current RMS of tripping/closing coil \\ r4 & Damage of tripping/closing coil & 12.63\% & f4 & Short current time of tripping/closing coil \\ r5 & Coil core jam or top rod deformation & 21.23\% & f5 & Long current time of tripping/closing coil \\ r6 & Dynamic contact connecting rod fault & 22.15\% & f6 & Long time of split/close of dynamic contact \\  & or transmission component jam & & & & Long asynchronism time of tripping/closing process \\ r7 & Excessive distance deviation between static and dynamic contacts & 5.61\% & f8 & Abnormal total stroke Excessive shell temperature of operating mechanism \\ r8 & Short residual life of motor & 3.2\% & f10 & Long pressing time for hydraulic/pneumatic actuator \\ r9 & Fault of energy storage motor & 3.25\% & f11 & Hydraulic/pneumatic operating system \\ r10 & Loop, seal ring and valves leakage & 14.31\% & f12 & Frequent start-up of oil/gas pumps \\ r11 & Pressure switch connection fault or pressure gauge malfunction & 2.04\% & f13 & Abnormal decrease in hydraulic/pneumatic pressure \\  & & & f14 & Abnormal rise in hydraulic/pneumatic pressure \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Table of partial fault reasons and partial fault features. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Number** & **f1** & **f2** & **f3** & **f4** & **f5** & **f6** & **f7** & **f8** & **f9** & **f10** & **f11** & **f12** & **f13** \\ \hline r1 & 0.45 & 0.4 & & & & & & & & & & \\ r2 & 0.4 & 0.3 & & & & & & & & & \\ r3 & & & 0.75 & 0.75 & & & & & & & \\ r4 & 0.55 & 0.8 & & 0.5 & & & & & & & \\ r5 & & & 0.4 & & 0.95 & & & & & & \\ r6 & & & & & & 0.75 & 0.5 & 0.7 & & & & \\ r7 & & & & & & 0.2 & 0.5 & 0.15 & 0.55 & & & \\ r8 & & & & & & 0.05 & & 0.15 & 0.45 & & & \\ r9 & & & & & & & & & 0.2 & 0.35 & 0.7 & \\ r10 & & & & & & & & & 0.8 & 0.65 & 0.3 & 0.95 \\ r11 & & & & & & & & & & & 0.05 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: The relation table between fault reasons and features of SF6 circuit breaker. partitioned, the part with a value equal to 0 can be separated from the part with data. This shows that part of fault reasons will only cause the fault features of the block part where these reasons are located, and there may be relations between the fault features in the same block part. When partial warning-level information is lost, the fault features related to the lost information can be used to calculate the probability of occurrence with the obtained fault features of the same block part. The fault reason tracking process is as follows:  
Step (1): After receiving the incorrect action information of a circuit breaker or relay protection device from the dispatching center, fault features of the device are extracted from warning-level information. The initial set of fault features (_F_1) is obtained. Step (2): Call the fault reason adjacency list of each feature in \(F\)1 and obtain the initial set of fault reasons as \(R\)1.