【正文】 adjacent areas. Protection device must have four basic properties: sensitivity, reflecting the ability of failure, usually expressed sensitivity coefficient. Reliability, in the action, refuse to move does not occur. Fast, the shortest time to failure or an exception will be eliminated. Selective removal of the smallest possible range of failure, ensuring maximum ponent continued to troublefree supply. Select protection programs, in addition to the above four set will need to meet basic performance, we must also pay attention to the economy. Protection device that not only take into account the investment and operation and maintenance costs must also be considered imperfect because of device malfunction occurs, or refuse to move to the national economy and social life losses. 2 and the effect of transformer protection Gas Protection Gas protection measures of protection as the main transformer, which can reflect the failure of the transformer tank and the oil surface decreased. When a minor fault when the oil level will go down in the case, the light gas moves in the signal, the time when a serious fault, it will produce large amounts of gas, heavy gas will produce trip, tripped circuit breakers on each side of the main transformer. For some of the load voltage of the transformer with a voltage regulator device, generally set the load of gas, and the same reason, when the action occurs when the gas light will be given a certain signal, when the heavy gas movement occurs when the trip occurred phenomenon. Relay operated circuit breaker trip, do not immediately revert to the signal swap cards, but should check the protection action, and to identify the reasons for the elimination of transmission before recovery before all the cards out all the reset signal. Differential protection Transformer differential protection as the primary protection response and terminations of the white transformer winding faults, it can jump on each side of the transformer circuit breaker. The recurrent protection voltage lockout Complex pressure response to the external phase lock overcurrent protection can be caused by a short overcurrent and as a gas, differential protection of the reserve. Action on the trip. The current and voltage transformer protection Changing external electrical fault occurred, resulting overcurrent transformer winding, and an internal fault in the transformer when the gas as a backup protection and differential protection, the transformer should be installed overcurrent protection. And according to the system shortcircuit current and transformer capacity of different, you can choose different protection methods, including lowvoltage start over current protection, over current protection, negative sequence overcurrent protection. 3 characteristics of power transformer relay protection system High reliability Information management system in substation relay protection, high reliability, because it uses methods of data warehouse and database, to facilitate system maintenance and upgrades. The entire information management system is no longer in operation prior to transmission to the distributed users at all levels, but concentrated in the center of the network database and rule base. Even if one of the customer39。s workstation problems, damaged, it will not affect the normal operation of the entire information system, and recovery is very simple, software developers, system upgrading library only limited ways, so that The whole process easy and convenient. practical Operation in the production of some of the practical problems, an effective solution to all types of data between the second part of the use and sharing. This system can analyze the system and the data statistics, which for the protection of the technical staff who have practical, can run a certain extent, improve the level of protection. Remote Monitoring Protection device with the PC serial munication function, and remote puter monitoring system substations to municate with contacts, so that the whole puter with remote monitoring of protection, which no one substation to provide a protective relay system. 4 Realization of power transformer protection Software applications The main query for all types of secondary information on the three remote realtime analysis of data processing, records of previous trial to pare fixed, accident, failure alarm events such as instructions and response time and the number of times the action statistics. The material of the secondary equipment testing, recording, management and valuation trial notice given by the protection officer by that date, to other department for advice and sharing. It can be achieved between the database and linked images and graphics are reflected in the existence of secondary equipment failures and defects, and records and the operation of protective devices for effective analysis. Set a parameter interface equipment, such as voltage, power and current records of test equipment can be effectively carried out with a wiring diagram of the main query, the system this as a secondary source of data, the assistant analysis can also be used for press release boards and to facilitate the exchange of information between departments and cooperation. Data Warehousing and method library Currently, the data warehouse is a traditional relational database than the original function more and more data organization, it is not only the application interface, nonstructural dynamic storage interfaces, and has a strong performance, but with vast amounts of data processing capabilities. In addition, the method library is able to package and store large amounts of processing the rule base is the concentrated expression of the application forms of software, it can save the integrity of the data, effectively limit the use of customers. The establishment of model system In recent years, with extensive use of put