In the following section, messages are grouped by type, and are supplied a description of conditions that can lead to the message as well as methods to correct the condition cited (if necessary).
"Diesel Gov1 Delay Table Size Exceeded."
Description - The Diesel Governor and prime mover model incorporates pure delay in the fuel activation path. To simulate this action, a delay table is incorporated within the model. This means that, given a particular simulation time step, the delay time allowed in the delay table can change, since the table length is fixed in the model. This is an initialization error, and must be resolved before your simulation can continue.
Fix – To remedy this condition, reduce the delay time, or increase the time step of the simulation. Note that decreasing the delay time affects only the single model where the change is made, but that increasing the time step affects all models in the simulation. Increasing the time step too much can also lead to numerical instability. We suggest reducing the delay time first.
"Round Rotor Gen Initialized."
"Salient Pole Gen Initialized."
"Ind2 Motor Initialized at Full Load."
"Ind2 Motor Initialized for PF Conditions."
"Synchronous Motor Initialized at Full Load."
"Synchronous Motor Initialized for PF Conditions."
Description - These messages indicate that the models noted are initialized properly, and are ready to run in the simulation.
"Ind2 Motor Load Transition - Starting to Running."
"Sync Motor Load Transition - Starting to Running."
Description - These messages indicate that the motor model’s load is starting its transition from starting load to running load.
"Unable to Refactor on Reset."
Description – This message involves the internal refactorization of the Y-Bus upon reset of a simulation. If this message appears, there are internal coding inconsistencies involving open and closed breaker status. This message should never occur during normal operation. If it does, contact EasyPower Technical Support, and please be willing to supply your database to us for diagnosis.
"Error - Cannot energize isolated subsystem with PV Gen."
Description – The starting up and synchronization of a generator takes a significant amount of automatic controls. Such controls have not been programmed into the present release of the Dynamic Stability Engine. This means that if a portion of a system is isolated before entering the DS Focus, and it has a PV gen, the gen is not enabled to start. This auto-start feature may be added in a later release.
"Power Flow Vars Not Settled for Induction Motors."
"Power Flow Solves Exceeded 10 Iterations for Induction Motors."
"Power Flow Settled in XX Solves for Induction Motors."
Description – These messages describe conditions when the power flow solution is iteratively used to get an initial condition power flow solution that matches the var requirements of induction motors. As noted in the Operations Manual, var requirements of the actual machine model may differ from those assumed in a power flow case. Thus the power flow is iteratively corrected, so that initial conditions exactly match the machine equation requirements. If conditions line up, then the “Settled” message is issued. If the power flow cannot converge, or converge quickly enough, one of the other two messages may precipitate.
Fix – If either the “Exceeded 10 Iterations” or “Vars Not Settled” message appears, the condition of your system is such that var requirements of induction motors cannot be met. This can be caused by a system that is near voltage collapse where the motors are connected, or when induction motor machine data has specified a motor that cannot meet the power requirements desired of it from the power flow (possibly moving the motor into a stall point for an initial condition). In either case, induction motor data should be reviewed and the power flow case should be inspected for unstable voltage conditions (a location where small changes in var loading cause large changes in voltage).
"ATS Transferred."
Description – This message alerts you to an automatic transfer switch that has been switched (toggled) to its alternate condition.
"ATS Transferred to Emergency Source."
"ATS Transferred to Normal Source."
Description – If an ATS has detected a loss of source and tripped (see just above), then after the delay time is satisfied, this message is generated. This notes that a transfer signal has been issued to the ATS, and it has performed its function. This is an informational message only, and in most cases does not signify an error or warning condition.
Note: If an ATS is transferring that should not be, we suggest a thorough review of the protective device settings for the ATS.
"Exceeded Result Storage Array Size."
Description - This message should never occur during normal operation. If it does, contact EasyPower Technical Support, and please be willing to supply your database to us for diagnosis.
"No PF Source for Ind2 Motor."
"No PF Source for Sync Motor."
"No PF Source for RR Gen."
"No PF Source for SP Gen."
Description - These messages should never occur during normal operation. If they do, contact EasyPower Technical Support, and please be willing to supply your database to us for diagnosis.
"DStates Not Settled, See Other Model Error Messages."
Description – During initialization, a check is made to see if the full model is settled. This is done by running one time step, and reviewing all DStates across all models. Given the DState is “the” value used to drive the integration calculation, and represents “changes” in a model’s condition, if the value of all DStates falls below a set threshold, then we can assume that the full model is settled.
Fix – We suggest reviewing all messages in the Message Log for a limit violation or other such warning. This is the most obvious reason for some DStates not being settled. However, if no other messages appear, but still the DStates are not settled, consider an additional step. Unsettled DStates occur in large system models where the DStates are very near being settled, but do not fall below the “Maximum Allowed DState” threshold. This is a setting in the Dynamic Stability Options dialog box, and can be increased if necessary to get a simulation to continue. If this threshold level is increased, we suggest doing so slightly until the “DState Not Settled” message goes away. Then after this, run the simulation in steady-state for 5 seconds (plotting several results) to verify that the system is indeed settled (all plotted results should produce a nearly flat line).
"DStates Settled for All Models."
Description – These messages note that all DStates are settled and that performing a simulation can proceed. “D” or differential states are indicators of change. If they are near zero and not growing, then the simulation is in steady state (not moving). When they are above a minimum level and growing, then changes are happening in the system, and the system is thus not settled, and thus not in steady state.
"Faulted."
Description – This message alerts you to a fault being applied on the noted bus.
"Fault Removed."
Description – This message alerts you that a fault which was applied (see just above) is now being removed from the noted bus.
"Contactor Dropped Out."
"Contactor Dropped Out in Isolated Sub-System."
Description – All contactors modeled with dynamic drop-out settings automatically drop out under voltage depression conditions of an impacting duration. This message alerts you to the drop-out action taken on the noted contactor. If a contactor is located on an isolated sub-system after solving an initial power flow condition, it automatically drops out, since the bus voltage on all buses in an isolated sub-system without a swing generator is zero. This message often appears just after initialization for a system where a contactor is modeled within an isolated sub-system.
"Contactor Dropped Out."
Description – If a contactor has sensed an under-voltage condition that exceeds its under-voltage setting and delay time, this message is generated. This notes that a signal has been issued to the contactor’s switching device, and it has performed its function (opened). This is an informational message only, and in most cases does not signify an error or warning condition.
Note: If a contactor is dropping out that should not be, we suggest a thorough review of the protective device settings for the contactor.
"Results Saved to Windows Clipboard."
Description – You can select to have all results copied to the Window’s Clipboard. When this action is performed, you are alerted to the action. The data is tab delimited and ready for import into Excel.
Note: Copying results to the Window’s Clipboard is time consuming, especially if the data set is large (lots of points and lots of curves). If this automatic action is slowing down display of simulation results, you can turn it off in the Dynamic Stability Options dialog box.
"Device Opened."
Description – This message is generated when a device (LV Breaker, HV Breaker, Switch, Fused Switch) is either opened by a script action, or opened automatically as a result of protective device action.
"Device Closed."
Description – This message is generated when a device (LV Breaker, HV Breaker, Switch, Fused Switch) is closed by a script action.
"Simulation Run To XX Seconds."
Description – This message is generated when a script command is processed which performs a Run To action. The time (XX) specified in the script command is also supplied.
"Simulation Run For XX Seconds."
Description – This message is generated when a script command is processed which performs a Run For action. The time (XX) specified in the script command is also supplied.
"Simulation Re-Initialized."
Description – This message notes that you reset the simulation. The next time the simulation is run, it starts from the beginning.
"Run Script XXX."
Description – This message notes that script XXX is being run as a response to your command.
"Can't run script. End time for simulation is zero."
"Can't run simulation. End time for simulation is zero."
Description – This message notes that the script being run cannot do so, because the commands have not specified a run time.
Fix – Edit the script and add or modify appropriate commands to get the simulation to run for a reasonable number of seconds.
"Control Setting Changed - Contactors Enabled."
"Control Setting Changed - Contactors Disabled."
"Control Setting Changed - Protective Devices Enabled."
"Control Setting Changed - Protective Devices Disabled."
"Control Setting Changed - Time Step Changed to %.4f."
Description – Repeatability of dynamic simulations is critical, especially at a later date, after a major simulation effort. The Dynamic Stability script definition tools and methods imposed on the Dynamic Stability focus make this critical aspect automatic. However, you still have the ability to make changes to run-time settings in the Dynamic Stability Options dialog box. If you want to make the changes part of a script so that a simulation is completely repeatable, then those changes should be included in the script. These messages alert you to control values being changed as the script is run.
"Torque vs. Speed Table Exceeds Internal Memory Limits"
Description – Under normal use, this message should never appear. It is an indication that the size of the Torque vs. Speed motor load curve in the library (and selected for the given motor) is exceeding the size of the physical memory limit in the Dynamic Stability Engine. There is most likely a programming error if this message occurs. Please contact EasyPower Technical Support, and be willing to supply your database to us for diagnosis.
"Simulation Auto-Stopped on Settled System"
Description – If the option in the Dynamic Stability Options dialog box is set for auto-termination of a simulation upon a settled system, then after the last script command is issued, and you are within a Run To or Run For command, if the DStates of all models fall below the set threshold, the simulation automatically terminates on a clear one second boundary time. This message is issued to note that the simulation auto-stopped.
"Divide by Zero in Class COMPLEX - COMPLEX/COMPLEX"
"Divide by Zero in Class COMPLEX - COMPLEX/DOUBLE"
"Divide by Zero in Class COMPLEX - DOUBLE/COMPLEX"
"Divide by Zero in Class COMPLEX - /=COMPLEX"
"Divide by Zero in Class COMPLEX - /=DOUBLE"
Description – Under normal use, these messages should never appear. The programming effort has included significant time to cover for all forms of model data entry where such conditions could arise. There is most likely a programming error if this message occurs. Please contact EasyPower Technical Support, and be willing to supply your database to us for diagnosis.
Fix - If this message appears after making a modification to model data, review that model data for correctness. There could be a condition where an inappropriate data arrangement slipped past data integrity checks in the equipment dialog box.
"Numerical instability encountered."
Description – This message appears when there is an issue with numerical instability in your simulation. As noted earlier, such conditions are typically associated with selecting too large a time step in comparison to specified model time constants.
Fix 1 – Reduce the time step of your simulation until the error goes away. If the error cannot be remedied with this fix, review Fix 2.
Fix 2 – For this problem to occur even after significantly reducing your time step, most likely there is a data integrity issue. We suggest reviewing model data for excessively small time constants, and then correcting them. If this problem occurred after a data modification, review that data modification for correctness.
"Stepping."
Description – This message appears when you are performing a step-run simulation. For every time you click the Step Simulation button, this message appears in the message log.
"Simulation Complete."
Description – This message appears when a simulation has been completed.
"Stability Focus Entry Failed on Power Flow Instantiation."
"Stability Focus Entry Failed on Data Transfer to Dynamic Stability Engine."
"Stability Focus Entry Failed on Power Flow Start."
Description – These messages appears when a failure occurs when entering into the Dynamic Stability focus. Under normal use, these messages should never appear. Please contact EasyPower Technical Support, and be willing to supply your database to us for diagnosis if you encounter these error messages.
"Stability Focus Entry Encountered Model Init Errors.”
Description – This message appears if there are errors that are occurring in Dynamic Stability models upon entry into the Dynamic Stability focus. This message also states: “Review Message Log for Details.” We recommend reviewing the Message Log to track down why this message appeared. More details will be supplied there for specific model initialization error conditions.
"Attempting Close - Device Already Closed."
"Attempting Open - Device Already Opened."
Description – If a switching device is asked to open or close, and it is already open or closed respectively, this message is logged to inform you that the switching operation attempted had no effect on the simulation.
"Exciter Stepped by XX%."
"Governor Stepped by XX%."
Description – When an excitation or governor system is stepped in a simulation, this message is generated to inform you of a successful step applied to the Reference Voltage or Reference Speed, respectively.
"Completing Script: XX."
Description – When a script is completed, this message is logged.
"Reset Encountered Model Init Errors."
Description – During a reset action (after clicking the Simulation Reset toolbar button), this message is logged if model initialization errors are encountered. This message also states: “Review Message Log for Details.” We recommend reviewing the Message Log to track down why this message appeared. More details will be supplied there for specific model initialization error conditions.
"Run Script (Stepping): XX."
Description – If a script is run while in a run-step mode, this message is logged.
"Grouped Motor XX has a Power Flow Scaling Factor of Zero."
Description – Grouped motors simulate their Power Flow Scaling Factor by scaling the total HP or kVA rating. If this value is set to zero, then we basically have a “zero” HP motor. This cannot be accommodated, as the HP or kVA of the motor group is used to scale many parameters in the model, and generates a zero divide situation in the Dynamic Stability Engine.
Fix – Either increase this scaling factor to a more reasonable number, or remove the motor in the Database Focus.
"Script Command to Change Time Step To %.7f Exceeds Allowable Range."
Description – The simulation time step cannot be set any higher than one cycle. If a script command is used to set the time step higher than that, then this message is logged.
Fix – Lower the time step change so it does not exceed one cycle.
"Bus To Fault Is Not Defined In Script."
"Device to Switch Not Defined In Script."
"ATS to Switch Not Defined In Script."
Description – If a device (Command ID) in a script command does not exist in the case, then one of these messages is displayed. Most likely, this message indicates that you are using an old script where a device action included a device ID that has been changed or deleted in the case. Or, the script could be trying to switch a device that has been deactivated in the case. In any event, the script command ID does not matches any presently defined and activated device ID.
Fix – Edit the script and change the device ID to match a device that is currently in your case and activated.
"Generator to Force AVR to Manual for Is Not Defined."
"Generator to Force AVR to Auto for Is Not Defined."
"Generator to Step AVR for Is Not Defined."
Description – If a generator asked to perform an AVR action is not defined, this message is logged.
Fix – Edit the script and change the device ID to match a generator that is currently in your case and activated.
"Generator AVR Set to Manual."
"Generator AVR Set to Auto."
"Generator AVR Stepped %6.2f %%."
Description – If a generator AVR command in a script is successful, then one of these messages is logged.
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