Dear Sir/Madam,<br/><br/>I would like to ask you about my problem in our power plant,<br/>exactly about protection relay coordination.<br/><br/>Case : When any disturbance at our grid, <br/>power plant almost always going into black out condition.<br/><br/>as I know, if we have disturbance at grid,<br/>power plant should not trip or black out and we operation use house load condition.<br/><br/>My question :<br/>what should I do, that if any disturbance at grid our power plant still in house load condition?