Causes and preventive measures of electric misoper

Causes and preventive measures of electrical misoperation accidents in substation operation

electrical misoperation seriously affects power safety production, especially malignant misoperation accidents, ranging from equipment damage and power loss to electrical stability damage and personal casualties. Substation maloperation accidents account for the largest proportion of power system maloperation accidents, and have been banned repeatedly. Especially in the past two years, the electrical maloperation accidents of the national power company system have increased. Therefore, it is necessary and urgent to study the causes of electrical misoperation in substation operation, find its internal law, and explore a good way to prevent accidents. Electrical misoperation refers to the violation of normal operating procedures caused by various reasons. The circuit breaker is opened and closed by mistake, the disconnector is opened and closed with load, the grounding wire (knife switch) is hung (closed) with power, the grounding wire (knife switch) is closed, the non synchronous paralleling, and the live interval is paralleled as a splint embedded workbench. After the experiment, the electrical malignant misoperation is coated with butter. On the surface, misoperation accidents are random and sudden, and in essence, they are inevitable and preventable. To study misoperation accidents, the most important thing is to find out the common causes and general laws behind them

according to relevant parties in the United States, every year the country "On the surface, the use of graphene in power cables may slightly increase the cost of products. 96% of the accidents that take more than 8 days off work are related to human unsafe behavior, and 91% of the accidents are related to material unsafe state. In Japan, 94.5% of the accidents that take more than 4 days off work every year are related to human unsafe behavior, and 83.5% are related to material unsafe state. Ⅲ these data show that most accidents It is not only related to human unsafe behavior, but also related to the insecurity of things. The following is to analyze the causes of electrical misoperation accidents from the two factors of people and things

I. the cause of the person who caused the electrical misoperation accident

1. bad reason buried the hidden danger of electrical misoperation

(1) fluke psychology. Heinrich, an American safety engineer, proposed the famous "300:29:1" rule, which means that if an enterprise has 300 hidden dangers or violations, 29 minor injuries or failures are bound to occur, and 29 minor injuries or failures must include a serious injury, death or major accident. This law also applies to power production enterprises. However, most substation operators only see a small probability of 1/330, and are lucky to think that the accident will not happen, even if it happens, it will not happen to them. If they ignore a major accident according to the above rules, there must be 29 "mild" accidents and 300 potential hidden dangers behind it. Being unaware of or insensitive to potential accidents may cause irreparable losses

(2) dependence psychology. Dependence psychology often weakens the subjective initiative and wisdom of the parties, leading to mistakes or accidents. In electrical operation, the dependence psychology is mainly manifested in that the ticket filler of switching operation excessively relies on the typical operation ticket or the intelligent operation ticket filling system; The operator and the guardian rely too much on each other; Or the operator relies too much on the voice prompt and operation guidance of some micro circle

machine error prevention locking device, and is used to following the machine over time, which weakens people's subjective initiative

2. Human error is easy to occur in the key links of operation

the switching operation of substation mainly includes 8 steps. Mistakes in any link may lead to misoperation. Five key links are prone to misoperation due to human factors

(1) the operation ticket is filled in incorrectly. The electric switching operation ticket defines the operation tasks, items and sequences in written form, which is an effective measure to prevent misoperation accidents. Filling in a correct operation ticket broadly covers the first three steps of switching operation: accepting operation tasks, filling in tickets, and reviewing tickets. In practice, it is easy to make mistakes in the operation ticket due to the following human reasons, resulting in misoperation: the dispatcher sends the operation task in advance and the operator on duty does not use the dual name and standardized operation terms of the equipment when checking and accepting, and the error in accepting the operation task is caused by the homophony, low call sound or local dialect, or there is a deviation between the receiver and the sender in understanding the same operation task, resulting in the mismatch between the operation ticket and the dispatching task. Some operators have low professional quality, and the quality of the operation tickets filled in is poor, or they do not fill in the operation tickets according to the dispatching steps and the current operation mode and equipment status, but copy the operation tickets or typical operation tickets with similar previous work tasks in an easy way, resulting in the deviation of the operation from the requirements. The guardian fills in the operation ticket on behalf of the operator, forming a situation of self filling and self-examination, and it is difficult to find mistakes. Or the reviewer just doesn't review or reviews the ticket carelessly, so the mistakes in the operation ticket can't be corrected in time

(2) operate without ticket or change the operation sequence without authorization. Individual operators on duty think they are familiar with the operation items and regard filling in the operation ticket as an optional or even redundant form, and fill it in after the operation is completed in order to cope with the inspection; Or even if there is an operation ticket, it will not be brought to the site, and it will be checked when the operation comes back. As a result, there is an error, resulting in misoperation. There are also operators who get into trouble, seek convenience and speed, and arbitrarily reverse the operation sequence, and then go to another place to operate after the operation at one place, resulting in missing items, violating the correct power cut-off and transmission sequence, resulting in misoperation

(3) operate without dispatching order or blindly without understanding the purpose of operation. The behavior of unauthorized operation without dispatching order is very bad, which is most likely to lead to misoperation. For example, a 220kV substation in Shaoyang, Hunan Province, closed the ground switch of its 220kV I bus without dispatching when dealing with the defect of 6001 disconnector. As a result, another worker unknowingly tried to close another disconnector on the bus, causing the disconnector to be closed with the ground, resulting in the complete shutdown of the 20kV bus of the substation and the loss of load of l9mw. Many switching operations in substations are coordinated operations. If you only pay attention to the operation part of the substation and don't understand the purpose of this operation, the operation will be very blind and lack of grasp of the whole. Once abnormal problems are encountered in the operation, you will be in a hurry and don't know how to deal with them, leading to misoperation

(4) there is no "three checks" before operation, and the inspection after operation is not in place. Misoperation caused by wrong interval accounts for a large proportion of substation operation accident cases. The reason is that the "three checks" are not carefully implemented before operation, that is, blind operation without checking the name, number and status; Or during the operation, one person temporarily left the operation site, and the other person moved his standing position while waiting on the site. When continuing the operation, the two people did not check the equipment again. The default is that the position where the waiting person stood is to operate the equipment, resulting in misoperation accidents. The position inspection of electrical equipment after operation shall be subject to the actual position of the equipment, but the actual position cannot be seen by switches (cabinets), central cabinets and closed combined electrical equipment widely used in ultra-high voltage systems in recent years, so it can only rely on indirect inspection. If the indirect inspection does not follow the diversified standards or does not compare the signals before and after operation, it is confirmed that the equipment has been operated in place, that is, the next operation, Otherwise, it is easy to cause machine failure, personal injury and other dangerous situations, violate the correct operation sequence, and misoperation occurs