The function can be enabled and disabled with the Operation setting. The corresponding parameter values are "On" and "Off".
The operation of MAPGAPC can be described using a module diagram. All the modules in the diagram are explained in the next sections.
Level detector
Level detector compares AI_VALUE to the Start value setting. The Operation mode setting defines the direction of the level detector.
| Operation Mode | Description |
|---|---|
| "Under" | If the input signal AI_VALUE is lower than the set value of the Start value setting, the level detector enables the timer module. |
| "Over" | If the input signal AI_VALUE exceeds the set value of the Start value setting, the level detector enables the timer module. |
The Absolute hysteresis setting can be used for preventing unnecessary oscillations if the input signal is slightly above or below the Start value setting. After leaving the hysteresis area, the start condition has to be fulfilled again and it is not sufficient for the signal to only return to the hysteresis area. If the ENA_ADD input is activated, the threshold value of the internal comparator is the sum of the Start value Add and Start value settings. The resulting threshold value for the comparator can be increased or decreased depending on the sign and value of the Start value Add setting.
Timer
Once activated, Timer activates the START output. The time characteristic is according to DT. When the operation timer has reached the value set by Operate delay time, the OPERATE output is activated. If the starting condition disappears before the module operates, the reset timer is activated. If the reset timer reaches the value set by Reset delay time, the operation timer resets and the START output is deactivated.
The timer calculates the start duration value START_DUR, which indicates the percentage ratio of the start situation and the set operation time. The value is available in the monitored data view.
Blocking logic
There are three operation modes in the blocking function. The operation modes are controlled by the BLOCK input and the global setting in which selects the blocking mode. The BLOCK input can be controlled by a binary input, a horizontal communication input or an internal signal of the protection relay's program. The influence of the BLOCK signal activation is preselected with the global setting Blocking mode.
The Blocking mode setting has three blocking methods. In the "Freeze timer" mode, the operation timer is frozen to the prevailing value, but the OPERATE output is not deactivated when blocking is activated. In the "Block all" mode, the whole function is blocked and the timers are reset. In the "Block OPERATE output" mode, the function operates normally but the OPERATE output is not activated.