Mechanism Analysis of Intelligent Diagnosis of Generator Electrical Faults

Analysis of Intelligent Diagnosis Mechanism of Electrical Faults in Generators YAN Bu-yi1, LIN Ji-qun1, LIN Li-qing2, JIANG Chuan-wen3, DU Song-huai3 (1. Department of Electrical Engineering, Fuzhou University, Fuzhou 350002, China; 2. Fujian Shuikou Hydropower Plant, Fuzhou, Fujian 350800, China; 3. Electrical Engineering, Shanghai Jiaotong University Department, Shanghai 200240) paste relationship, established fuzzy relation equation, realized intelligent diagnosis, and realized simulation operation by software, the diagnosis result was accurate and reliable. : Generator; electrical fault; intelligent diagnosis of the operating state of the generator directly affects the safety and economy of the operation of the power system, timely and accurate determination of faults in operation is very important. However, it is quite difficult to monitor the operating conditions and perform online diagnosis under operating conditions. The research on intelligent diagnosis of power system faults is very active at home and abroad, but there is less overall research on electrical fault diagnosis of generators. In this paper, combined with the operating experience of power plants and power grids, the artificial intelligence principle is used to realize the electrical fault diagnosis of generators.

Since the generator failure phenomenon is closely related to the cause of the failure, each failure phenomenon may be caused by one or more failure causes, and each failure will cause certain phenomena correspondingly, plus a large generator. There are many kinds of faults, so the complexity and ambiguity of the fault phenomenon, cause and mechanism are difficult to describe with accurate mathematical model, and it is difficult to completely rely on the deterministic criterion to determine the nature of the fault. This paper will be the experience of generator operation and expert system. The principle and fuzzy theory are combined to find out the fuzzy relationship between the cause and phenomenon of electrical faults in generator operation. The fuzzy diagnosis is used to realize the intelligent diagnosis of electrical faults of generators. The introduction of fuzzy theory can solve some factors in the production process. The uncertain relationship between each other, in the field of electrical fault diagnosis of generators, the fuzzy relationship matrix can be used to reflect the relationship between some fault phenomena and the cause of the fault, as described below.

Let XY denote the input and output respectively, and represent the quantized set of the fault cause and the fault phenomenon respectively, then: 1, 2, ..., n; then the fuzzy relation equation is: where R = (ri /) mKn, ri / belongs, The relationship strength between Xi and y, r/=0 means irrelevant, the larger ri/, the closer the relationship, the smaller n/ is, the smaller the relationship. , Yongtai, Fujian, lecturer at Fuzhou University.

Analysis of common causes and phenomena of electrical faults in the line. First determine the input, that is, the electrical fault cause matrix X, such as the stator A phase ground fault, see Table 1 and then determine the output, that is, the electrical fault phenomenon matrix Y, such as UaI represents the phase A voltage drop of the machine, denoted by y4, detailed See Table 2 Table 1 Input Fuzzy Set (Fault Cause) Fault Cause Input Fault Cause Input Stator A Phase Ground Rotor One Point Grounding Stator B Phase Ground Rotor Two Points Grounding Stator C Phase Grounding Running Loss of Magnetic Stator Three Phase Grounding Accident Overload stator A phase inter-turn short circuit external short circuit fault stator B phase interturn short circuit stator C phase interturn short circuit table 2 output fuzzy set (fault phenomenon) fault phenomenon output fault phenomenon output fault phenomenon output An U Ua / A /b Uf Ub / c / f C Table 2, A. is the machine zero sequence current; is the machine zero sequence voltage; Q <0 is the reactive meter indicates a negative value; U is the stator Insulation monitoring voltage; (/a-/a) is the differential current of the primary and secondary sides of the differential protection relay; Ilhn is the neutral unbalance current; U is the positive voltage of the rotor winding to ground; Uf is the excitation voltage; /f is The rotor current is combined with the operating experience of a thermal power unit in a power plant and consulted relevant experts. The fuzzy relationship matrix R between the fault cause and the fault phenomenon is formed. See Table 3 in Table 3 for the relationship between 23 electrical fault phenomena and 12 electrical fault causes to indicate the relationship strength between x and y/. , 0.9 indicates a close relationship, 0.5 indicates a general relationship, and 0 2 indicates a small relationship. Representing how to determine the fuzzy relation matrix elements and thresholds is the key to determining the correctness of fuzzy reasoning. Their value is a reflection of expert knowledge and generator operation practice, which is derived from long-term analysis and refinement. For the evaluation of the fuzzy relation matrix element ri/, the "fuzzy statistical method" can be used.

The value should not be greater than the largest element in the output matrix. If Xi>w, then y/ is probably caused by xi; if xi If a fault occurs, the following phenomena occur: the zero-sequence current and voltage of the terminal rise sharply, the AC phase voltage of the terminal rises, the B-phase voltage drops significantly, and the B-phase current rises, and the stator insulation monitoring voltage indicates. Combined with the fault knowledge, it can be obtained that the most likely failure probability is X2 = 0.8 (only the maximum solution is obtained), which means "stator B phase ground fault" and hypothesis: the fuzzy relation equation formed There is no solution. At this time, pattern recognition can be used to further supplement the reasoning to determine the cause of the fault. The fuzzy relationship matrix between the cause and phenomenon of the electrical fault of the generator is called 14 and 19 closeness formula |61: (, N(Y, x,) indicates the closeness between the fault symptom set Y and a fault cause x, and can be obtained: N(Y, x7) = 0.784 is the largest, so the most likely fault is "stator If the C-phase short-circuit fault is faulty or other faults (that is, faults that are not in the input fuzzy concentration), if the elements in the fault symptom set Y are incomplete for some reason, the fuzzy equation cannot be established, then pattern recognition is also possible. The system is mainly composed of knowledge base, fault information base, inference engine, pattern recognition and human-machine interface. The various fault knowledge of the generator is represented by the structure of the C language. The programming is easy to form the inference function. The compiled executable program runs fast. 5 Conclusion This paper combines the generator operation experience with the expert system principle and fuzzy theory. The fuzzy relation equation between the electrical fault cause and the electrical fault phenomenon of the generator is established. In some cases, the relational equation with no solution is supplemented by the pattern recognition method, which makes up for the deficiency of the expert system and the fuzzy relation equation. The fault diagnosis is realized well, and the simulation operation is realized by software. The running speed is fast and the diagnosis result is accurate and reliable. However, the formation of the fuzzy relation matrix element in the text is still preliminary, and more abundant historical data and operation practice are needed to be corrected.

Granulator Machine

The granulator machine can make granules from wet powder materials or break down the dry lumpish material, which is widely used by the industries of pharmacy, chemical and foodstuff. By driving of mechanism, the cylinderis swinging to-and-fro to force the target material squeezed from sieveto make out granules or to smash it as granules. This granulation machine is made of stainless steel, in line with GMP standards.

Granulator Machine,Pelletizer machine,Pelletizing Machine,Dry Granulator,Granulation Machine

JIANGYIN CITY XUAN TENG MACHINERY EQUIPMENT CO.,LTD , https://www.xuantengmachine.com