6. Quickstart Cursor Metrics
From MTB 2.0, cursor metrics can be used to calculate selected values from RMS and EMT result signals over defined cursor time intervals. The available cursor metrics are:
- START returns the signal value at the start cursor time.
- END returns the signal value at the end cursor time.
- DELTA returns the difference between the signal value at the end cursor time and the signal value at the start cursor time.
- MIN returns the minimum value of the signal between the start and end cursor times.
- MAX returns the maximum value of the signal between the start and end cursor times.
- MEAN returns the mean value of the signal between the start and end cursor times.
- GRAD_MIN returns the minimum value of the signal's numpy.gradient between the start and end cursor times.
- GRAD_MAX returns the maximum value of the signal's numpy.gradient between the start and end cursor times.
- GRAD_MEAN returns the mean value of the signal's numpy.gradient between the start and end cursor times.
- RESPONSE returns the response delay time from the start cursor time until the signal has reached 10% of the DELTA value.
- RISE_FALL returns the rise or fall time by measuring the time from 10% to 90% of the DELTA value.
- SETTLING returns the settling time from the start cursor time until the signal remains within the tolerance band, default 2%, around the END value.
- OVERSHOOT returns the peak overshoot percentage and an estimated damping ratio.
- FSM_DROOP returns the FSM droop calculated from active power and frequency.
- LFSM_DROOP returns the LFSM droop calculated from active power and frequency.
- QU_T1 returns the Q(U) t1 response time as RESPONSE plus RISE_FALL.
- QU_T2 returns the Q(U) t2 settling time using a 2% tolerance band.
- QU_DROOP returns the Q(U) droop calculated from reactive power and voltage.
- QU_SS_TOL returns the Q(U) steady-state tolerance compared with the required reactive power change.
- DELTA_FFC returns the required fast fault current contribution and the difference to the measured current response.
The cursors to be used for each Case/Rank are configured using the cursorSetup.csv file.
| Column Name | Description |
|---|---|
| title | A descriptive name that is used for the cursor metric table |
| rank | The case rank number for which the cursor metric table will be generated |
| cursor_options | A comma-separated list of cursor functions to be applied |
| emt_signals | A comma-separated list of the EMT signals to be used by the cursor functions |
| rms_signals | A comma-separated list of the RMS signals to be used by the cursor functions |
| time_ranges | A comma-separated list of the cursor start and end times, entered in pairs |
Most cursor functions only require one signal. The exceptions are FSM_DROOP and LFSM_DROOP, which require active power and frequency signals, for example MTB\P_pu_PoC and MTB\pll_f_hz for EMT, and meas\s:ppoc_pu and meas\s:f_hz for RMS. QU_DROOP and QU_SS_TOL require reactive power and voltage signals, for example MTB\Q_pu_PoC and MTB\meas_Vag_pu for EMT, and meas\s:qpoc_pu and meas\s:Vag_pu for RMS. DELTA_FFC requires reactive current and positive-sequence voltage signals.
The cursor time ranges define the start and end time of each cursor pair, for example:
- 0.0 - the cursor functions are applied to the time range from 0.0 s to the end of the simulated signal.
- 0.0, 10.0 - the cursor functions are applied to the time range from 0.0 s to 10.0 s.
- 0.0, 10.0, 10.0 - the cursor functions are applied to the time ranges from 0.0 s to 10.0 s and from 10.0 s to the end of the simulated signal.
- 0.0, 10.0, 10.0, 20.0 - the cursor functions are applied to the time ranges from 0.0 s to 10.0 s and from 10.0 s to 20.0 s.
- 0.0, 10.0, 10.0, 20.0, 20.0 - the cursor functions are applied to the time ranges from 0.0 s to 10.0 s, from 10.0 s to 20.0 s, and from 20.0 s to the end of the simulated signal.
The cursor time ranges can overlap, but each explicit pair must obey that end time > start time, for example:
- 0.0, 10.0, 5.0, 15.0 - the cursor functions are applied to the time ranges from 0.0 s to 10.0 s and from 5.0 s to 15.0 s.
The cursor functions are defined in cursor_functions.py. The numbering below follows the CursorType enum order in cursor_type.py.
Returns the signal value at the start of the cursor interval.
Returns the signal value at the end of the cursor interval.
Returns the difference between END and START.
e.g. Rank_11: ION_RfG_P_step_up_0 0_0 5
Returns the minimum signal value in the cursor interval and the time at which it occurs.
Returns the maximum signal value in the cursor interval and the time at which it occurs.
Returns the mean signal value in the cursor interval.
e.g. Rank 7: PRE_SS_flatrun_Uctrl1
e.g. Rank 7: PRE_SS_flatrun_Uctrl1
Returns the minimum signal gradient in the cursor interval. The result is reported in pu/min.
Returns the maximum signal gradient in the cursor interval. The result is reported in pu/min.
Returns the mean signal gradient in the cursor interval. The result is reported in pu/min.
e.g. Rank_11: ION_RfG_P_step_up_0 0_0 5
Returns the response delay time from the start of the cursor interval until the signal has reached 10% of the DELTA value.
Returns the rise or fall time from 10% to 90% of the DELTA value.
e.g. Rank 17: ION_RfG_FSM_step1
Returns the settling time from the start of the cursor interval until the signal remains within the tolerance band around the END value. The default tolerance is 2% of DELTA.
Returns the peak overshoot percentage and an estimated second-order damping ratio.
e.g. Rank 38: ION_RfG_Ucontrol_Scmin-Cursor-Reactive_power
Returns the FSM droop value calculated from active power and frequency. The FSM deadband from the test case settings is included in the calculation.
Returns the LFSM droop value calculated from active power and frequency. The DK1/DK2 LFSM threshold is selected from the test case settings.
Returns the Q(U) t1 response time, calculated as RESPONSE + RISE_FALL. This allows the metric to be used directly with RfG Article 21.3 (d)(iv) from NC RfG - Nationale krav.
Returns the Q(U) t2 settling time, calculated using SETTLING with a 2% tolerance band. This allows the metric to be used directly with RfG Article 21.3 (d)(iv) from NC RfG - Nationale krav.
Returns the Q(U) droop calculated from the change in reactive power and the change in voltage over the cursor interval.
e.g. Rank 38: ION_RfG_Ucontrol_Scmin-Cursor-Reactive_power
Returns the Q(U) steady-state tolerance as the deviation between the measured reactive power change and the required reactive power change, expressed as a percentage of Qnom.
Returns the required fast fault current contribution based on the positive-sequence voltage and compares it with the measured change in reactive current over the cursor interval.