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Metering Points

One must first define, configure, and put on-line one or more metering points.

 

Schedules

The next step is to define the schedules. Each schedule needs to be defined, configured, and put on-line.

 

Demand Points

To build a list of demand points, one needs to define each demand point, configure it, and put it on-line by adding it to one of the metering points.

Each demand point must be mapped to an analog point, which can be done by appropriately specifying RUEX domain, remote unit, and analog point identifiers.

 

Load Points

To build a list of load points, one needs to define each load point, configure it, and put it on-line by adding it to one of the metering points.

Each load point must be mapped to a control point, which can be done by appropriately specifying RUEX domain, remote unit, and control point identifiers.

If associated RUEX remote unit has two-way capabilities, and there is a counter available on that remote unit, the load point must also be mapped to that counter. The latter assignment can be left as NONE if two-way load management is not going to be performed. 

Each load point must also be mapped to an appropriate schedule, or schedules, if multiple load management strategies are going to be executed. 

 

Data Processing

RUEX analog point thresholds must be defined (high threshold must be larger than low threshold),  otherwise LMEX does not accept analog point values as valid. LMEX also rejects any values outside the range defined by the thresholds.

Each demand point must be configured to either add or subtract its value to the owner metering point demand total value. That same parameter can also be set so no contribution is made to the metering point total.

Each metering point must be configured to either add or not add its value to the system demand total value.

 

Data Recording

To record system total demand, one must enable LMEX NTMCRDR.

To record metering point total demand, one must enable metering point NTMCRDR.

To record demand point total demand, one must enable demand point NTMCRDR.

To record load point activity, one must enable corresponding RUEX control point NTMCRDR. In addition, RUEX records control point activity into RUEX event log file. See documentation on RUEX Control Point Operation Logging parameter.

To generate system total load management cycle logs, one must enable Load Management Cycle Logs parameter.

To generate metering point load management cycle logs, one must enable metering point Load Management Cycle Logs parameter. To get individual demand input resolution one must set this parameter to MPT and Demands.

 

Data Archiving

One has to periodically archive data and event logs. Both operations are manually initiated by the operator.

Data archiving is initiated by executing the LMEX Archive Data Recording Files command. The accumulating data files get appended to the corresponding archives located in the NTMCRDR archive directory.

Event log archiving is initiated by executing the LMEX Archive Event Log File command. The accumulating event log file gets copied to the NTMC event log archive directory, common to all NTMC components, and reset to empty.

Data recording files and event log file can be periodically archived automatically if so desired. Care must be taken that archive directory is always available and in the same place, otherwise archives are scattered in different locations, and historical searches become inconvenient.

Billing Periods

To distinguish between peak and off-peak billing periods, peak billing period start and end times of day must be defined.

Furthermore, global weekday management must be enabled on the day of the week for peak billing period to be in effect that day.

In addition, when load management waiver is in effect, off-peak billing period is in effect.

By definition, when peak period is not in effect, off-peak period is in effect.

MCDA LMEX billing period data filtering can be performed when analyzing NTMCRDR and RURDR data.

 

One-way Load Management

In all cases

  1. Load management must be enabled.
  2. Global weekday management must be enabled on the day of the week load management is to be performed.
  3. Global start and stop management times of day must be defined properly. In order to be effective, any lower level start and stop times (such as schedules) must be at least as restrictive, or more restrictive than the global start and stop times mentioned above. 
  4. Pre-management time must be defined if initial shed is to begin before above start management time of day. This is used when control code dispatcher uses substantial amount of time to dispatch control codes due to low communication speeds.
  5. If RUEX polling period is to be controlled dynamically, Dynamic RUEX Polling Period Control must be enabled. See also documentation on this parameter regarding RUEX setup.
  6. Active Cycle Demand Correction should be enabled.
  7. Shed Ramping Rate, Restore Ramping Rate, and High Threshold Overruns to Reset parameters can be set if desired.
  8. All metering points involved in load management must be enabled.
  9. All metering points involved in load management must have Load Rating Bias Factor parameter defined properly. If, for example,  it seems that, on the average, only 75% of the loads are running at any one time, the value of this parameter should be set to 75.
  10. All demand points involved in load management must be enabled.
  11. All demand points involved in load management must have the Contribution to Metering Point parameter defined appropriately.
  12. All load points involved in automatic load operations must be enabled, and in Auto mode. Similarly for the associated RUEX control points - they must be enabled and in Auto mode.
  13. All load points involved in automatic load management must have the Load Type, Primary Load Metering Point, and Primary Load Id parameters defined appropriately. The latter two are ignored when the Load Type parameter is set to Primary.
  14. All three load point schedule assignments (Primary Strategy, Secondary Strategy, and Emergency Strategy) should be pointing to the same schedule.
  15. All schedules involved in load management must be enabled.
  16. Schedule weekday management must be enabled on the day of the week load management is to be performed, otherwise loads assigned to the schedule are kept in the ON state (connected to the power grid).
  17. Schedule start and stop management times of day must be defined properly. Load points assigned to the schedule are kept in the ON state (connected to the power grid) during times of day which fall before the start time, or after the stop time defined in the schedule. Careful: if the time window defined here has no overlap with the global time window (global start and stop time of day described above), loads assigned to the schedule will never be disconnected from the power  grid. 
  18. Load Shed Priority and Load Restore Priority parameters can be defined to control load operation priorities. Load point shed priority is determined as follows:
    1. Schedule shed priority - parameter defined in the schedule, the lower the value, the higher the priority.
    2. Load activity.  Active load has higher priority to be disconnected. Activity rate is immaterial, LMEX only considers activity vs. no activity. Otherwise active loads would be turned off more frequently.
    3. Number of times load was turned off in a day. Loads which have been disconnected fewer times have higher priority. Numbers are reset at midnight.
    4. Load point Accumulated Off Time (AOT) - the lower the value, the higher the priority.

    Load point restore priority is determined as follows:

  1. Schedule restore priority - parameter defined in the schedule, the lower the value, the higher the priority.
  2. Load point Accumulated Off Time (AOT) - the lower the value, the higher the priority.
  1. Max. Number of Loads Off, Max. Sheds per Day, Max. Failed Operations per Day, and Max. Load Accumulated Time Off parameters may have to be defined to impose the various limits defined by the parameters.

 

Global load management:

  1. Global Demand Management Method parameter must be set to Global.
  2. High and low demand thresholds must be specified. The former must be greater than the latter, and they must not be too close together in order to prevent system demand oscillations. LMEX sheds load when it exceeds the high threshold, it attempts to bring it under the high threshold. LMEX attempts to restore load when it falls below the low threshold, it tries to restore enough loads to bring the load just below the  high threshold.
  3. All metering points involved in load management must have their Demand Management Method parameter set to Global.
 

Metering Point load management:

  1. Global Demand Management Method parameter must be set to Metering Point.
  2. Metering point High and low demand thresholds must be specified. The former must be greater than the latter, and they must not be too close together in order to prevent metering point demand oscillations. LMEX sheds metering point load when it exceeds the high threshold, it attempts to bring it under the high threshold. LMEX attempts to restore metering point load when it falls below the low threshold, it tries to restore enough loads to bring the load just below the  high threshold.
  3. All metering points involved in load management must have their Demand Management Method parameter set to By Metering point.
  4. High Threshold Overruns to Reset parameter may be defined if dynamic high threshold control is desired.

 

Two-way Load Management

In addition to one-way load management parameters (above), the following must be defined:

  1. Two-Way Load Management parameter must be Enabled.
  2. All metering points involved in load management must have Load Rating Bias Factor parameter set to 100.
  3. All metering points involved in load management must have Load Pulse Threshold Bias Factor defined properly. The value must be 100 or less, depending on the remote unit model used, and configuration of that remote unit.
  4. Each load point involved in load management must have Energy Per Pulse parameter properly defined. Same units of measure as those in load Power Rating parameter must be used.

Any parameter documentation in this section, which is in contradiction to that defined in the One-way Load Management section, takes precedence over that defined in the One-way Load Management section.

 

Strategy Based Load Management

In addition to one-way or two-way load management parameters (above), the following must be defined:

  1. If Strategy Selection Method parameter (above) is set to Global, LMEX Strategy parameter must be properly defined. 
  2. If Strategy Selection Method parameter (above) is set to Metering Point, every metering point must have the following parameters properly defined as follows:
  1. If Load Management Strategy Selection Method parameter is set to Manual, Load Management Strategy In Effect parameter must be defined. The latter determines load management strategy in effect.
  2. If Load Management Strategy Selection Method parameter is set to Time of Day, Primary Load Management Strategy Start Time of Day and Secondary Load Management Strategy Start Time of Day parameters must be defined. Strategy in effect is thus depends on the time of day.
  3. If Load Management Strategy Selection Method parameter is set to Demand, Demand High Threshold and Demand Low Threshold parameters must be defined. Strategy in effect thus depends on metering point load. 
  1. All three load point schedule assignments (Primary Strategy, Secondary Strategy, and Emergency Strategy) should be pointing to appropriately defined schedules.
  2. Every schedule must have Load Control Authority parameter properly defined. 
  3. When above parameter is set to Demand Management Algorithm, every schedule Load Control Factor parameter must be defined.

Any parameter documentation in this section, which is in contradiction to that defined in the One-way Load Management section, takes precedence over that defined in the One-way Load Management section.

 

Load Rotation

For load rotation to work, load rotation manager must be Enabled. In addition, every schedule involved in load rotation must have the Load Rotation Period parameter set to a positive value. Load Control Authority and Load Control Factor parameters must also be defined properly.

 

Load State Reinserting

For Load State Reinserting to work, LSR manager must be Enabled. Reinserting Time of Day parameter must be defined to specify the time of day when reinsertion codes are to be transmitted, or Reinserting After Peak Period parameter must be defined to specify how long after peak billing period expires reinsertion codes are to be transmitted.

If the parameter is defined more than once, the codes go out several times per day. For each time of day the Reinserting Method parameter must be defined so LMEX knows which control codes to send out.

 

Load Pre-polling

For load pre-polling to work, LMEX Load Pre-polling parameter must be Enabled. Pre-polling Pass 1 and Pre-polling Pass 2 parameters must be defined. Every load to be pre-polled must have the Pulse Counter parameter defined, pointing to a valid RUEX pulse counter residing on the same RUEX remote unit as the control point used to operate the load.

For NTMC systems which include MREX, the automated meter reading component, one latest meter reading operation can serve as one pre-poll, as long as MREX meters are mapped to the same pulse counters as the above described loads.

Furthermore, only one pre-polling pass can be used if desired. One advantage using two pre-polling passes is to have more recent data. One disadvantage of pre-polling twice is that the system takes more time polling for data. The latter can take substantial amounts of time on systems limited by slower baud rates, such as systems using radio communications.

 

Load Point Operation Modes

Put the load in AUTO or MANUAL mode. Frozen mode comes about from operating the load manually via the web.

 

Load Management Waivers

To waive load management for part of the day, first define Load Management Waiver Start Time of Day and Load Management Waiver End Time of Day parameters, then set the Load Management Waiver parameter to Enabled. The latter parameter gets set to Disabled automatically the next midnight.

These parameters can be manipulated externally via communications channel of choice. Custom protocols are available upon request.

To receive waiver notification messages via a modem, Nebraska Public Power District customers in the state of Nebraska must set up a dedicated telephone line, a modem,  then set up one NPPD type IOEX application client and one NPPD type IOEX application server using that telephone line and the modem. The server has to be enabled and properly configured with correct addresses - see documentation on IOEX NPPD type servers.

 

Secondary Load Points

To define a load point a secondary load point, the Load Type parameter must be set to Secondary, Primary Load Metering Point parameter must identify the metering point which contains the primary load point, and Primary Load Id parameter must identify that primary load point.

Multiple secondary loads can be assigned the same primary load point. When the latter changes state, all associated secondary load points are sent corresponding control codes or notifications.

The following rules must be observed when defining secondary loads:

  1. All secondary loads must be assigned to a schedule which is completely unrestricted, i.e. enabled, available every day of the week, at all times of day.
  2. Each secondary load must be assigned zero power rating.
 

Twin Load Points

To define a load point a twin load point, the load point must first be defined as secondary (see above). The corresponding primary load point must then identify this secondary load point as a twin load point. There can only be one twin load point for every primary load. The following primary load point parameters must identify the twin load:

  1. Twin Load Metering Point Id
  2. Twin Load Id

If twin load so identified is not a secondary load, it does not operate as a twin load. Twin loads must be secondary loads to prevent the scenario where automatic load management first operates a twin load, without operating associated primary load point.

 

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