DEVELOPMENT OF PROTECTION SETTING VALIDATION CONCEPT BY USING EXPERT SYSTEM

• Main Author: Bakti Krisnamurti W., Dheka
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49226
• Institution: Institut Teknologi Bandung

Setting values (parameter values) of equipments (motor, generator, transformer, bus, and line) and system protection coordinations are not optimal (selective) cause a not expected disturbance on electrical power system. These problems can be seen in a Pacitan power plant case on 2014, where a tripped circuit breaker of medium voltage motor caused a circuit breaker of power source incoming tripped, so the power plant tripped. Other cases, many distribution and transmission systems (20 and 70 kV) disturbances caused circuit breakers of generator tripped, so power plants could not be operated island or house loads. The parameter value problems because many protection experts who they are from units of electrical company moved to other job descriptions or to other units, so they do not have protection experts and have to conduct regeneration to result new protection experts or they can use a protection consultant to optimize the parameter values. However, by using the consultant will spend much money. Therefore, for accomplishing the parameter value problems can use an expert system application that it works based on knowledgebases of the protection experts, so not need spend much money to pay the consultant. Actually, the application had been developed, but it still use interviews or dialogs between an user (a non expert engineer) and it (expert engineers), so when there are the protected equipments or system configuration (topology) changes, it has to conduct interviews again. Therefore, a new expert system application is needed that it is a development of the previous application and can work automatically. Methods of the application use rule based expert system and blackboard approach method with forward chaining as an inference engine, it is such as the previous application and eliminate the non expert engineer, so it can work automatically. Protection function rules are based on the knowledgebases. A protection function contains many rules that they are adapted with equipments or system data (facts). A rule results a protection function parameter value. Therefore, needed optimization process to result optimal protection function parameter values. Used protection devices are products from Siemens, so protection function parameters of the application are adapted with them. An used software to develop the application is Anaconda with Python programming language. This is because the topology is configured by PSS Sincal software (as an user) and the programming language can take datas of the topology as inputs from a database of the software. iv After that, the datas will be processed and result the parameter values as outputs automatically by the programming language. There are 2 validation processes, namely topology validations and protection function parameter value validations. The topology validations are conducted by comparing equipments or system topology in PSS Sincal with topology datas (user interface results). The parameter value validations are conducted by representing protection function parameter values in grading diagram to know sensitivity, rapidity, and selectivity of protection function coordination. The topology datas and the parameter values will be changed automatically when there are protected equipments or system topology changes. The validation processes are conducted by using a line network sample. By obtained the parameter values automatically, so an expert system application can eliminate errors of an non expert engineer and cost of a protection consultant. Other advantages, the optimal parameter values will decrease problems or disturbances in power plants, transmissions, and distributions, so they will increase revenues and customer services and decerease production costs.