kitControl-ElectricalDemandLimit
This component provides load shedding calculations based upon projected electrical demand averaging. It uses a sliding window interval, which can be configured.
ElectricalDemandLimit is available in the Energy folder of the kitControl palette along with related objects SetpointOffset and ShedControl.
Electrical Demand Limiting (EDL) is an energy management tool for leveling out fluctuations that may occur in daily energy demand levels. Energy providers often set billing rates based on periodic maximum demand levels. It is possible that a single day (an anomaly) could dramatically increase a monthly billing rate. Reducing peak demand levels can significantly lower energy costs even if the total energy consumption does not change. To avoid costly spikes in demand level, this component monitors and controls building and enterprise energy usage.
To use the ElectricalDemandLimit component, as a minimum, you need to do the following:
| Property | Value | Description |
|---|---|---|
| Prediction Enabled | true (default) or false and null definition | Turns this component on and off. true enables this component. This value must be set to true for the component to work. false disables this component. When null is checked, the value displayed defaults to the incoming value from the device. If you remove the check mark you can configure theIn value. |
| Power Input | kW rate and null definition (defaults to 0) | Defines the power demand (kW) rate. The component uses this
value to average the demand rate over every minute for comparison
with the Projected Demand Average. This property
should represent the total actual demand rate — the total of
all meters monitored by this component on the energy network. When the component invokes a shed or restoration, this value is expected to change in relation to the estimated values configured for the Power Shed Level properties. When null is checked, the value displayed defaults to the incoming value from the device. If you remove the check mark you can configure theIn value. |
| Message | read-only text | Displays information that relates to the status of the shed, restoration, or projected demand values, and may indicate the status of the EDL component, itself. |
| Shed Out | number and null definition (defaults to 0) | Displays a value that indicates the number of levels to
be shed. For example, a Shed Out value of 3 indicates that a Power Shed Level of 3 is being
shed. When null is checked, the value displayed defaults to the incoming value from the device. If you remove the check mark you can configure theIn value. |
| Billing Start Day | date | Specifies the first utility billing day of the month. This aligns system data with the actual energy company billing periods. Each month, on the day specified by this property, the current month’s data move to the previous month, and the current month’s data become this month. |
| Demand Interval | 15 or 30 minutes (defaults to 15 minutes) | Configures the demand window used to calculate the average.
You may change this value to 30 minutes. Any other value reverts to
15 minutes. The larger demand interval has more data points (one per
minute) than the smaller interval. Depending on the value of the Percent Interval Elapsed property, the data points may be comprised of mostly sampled historical demand values, mostly values that are projected (based on current demand), or half and half. |
| Percent Interval Elapsed | percentage (defaults to 75) | Determines how much of the calculated demand is based on
actual demand as opposed to how much is based on projected demand.
A value of 50 calculates the Projected
Demand Average using half of the actual sampled (or historical)
values and half of the projected values. To calculate projected demand, the component uses current energy data at the current minute. In a 15 minute demand window, a value of 67 means that the current minute is 10. Larger numbers in this property increase the amount of historical data used and decrease the amount of data that are based on the current minute demand. |
| Rotate Level | a number from 1 to 32 (defaults to 0) | Specifies the maximum Shed Level to use. For example, a value of 3 limits load shedding to Power Shed Level3. |
| Demand Limiting Deadband | kW | Sets a deadband value the component uses to determine whether or not to invoke a restoration when activating restoration levels. The component does not use this value to invoke shed actions. |
| Demand Limit Period(n) | kW | These three values set demand limits that correspond to each of the three daily periods. When energy usage exceeds the Demand Limit value for a period, load shedding begins. |
| Demand Period(n) Start | hours minutes seconds (default to 0) | These three values split up a 24-hour day into three time-periods used to assign a separate demand limit for each distinct time. |
| Power Shed Level(n) | a number to two decimal places | These levels set up to 32 demand limit values based on the
loads that are controlled by the specific shed group. Each value represents
the amount of demand to shed when the component invokes the associated
shed level. The component may invoke one or more shed levels to lower
the demand below the current Demand Period limit.
In other words, the load-shed logic calculates how much demand is
required to be reduced, and then uses these values to determine how
many loads to shed. Once the component invokes a shed level is invoked, it evaluates the actual power drop at the next minute to determine the effect of the shed action. If the initial load shed does not actually reduce the demand below the limit, the component invokes the next shed level (if any). To limit the number of shed levels the component may invoke, configure the Rotate Level property. |
ElectricalDemandLimit data – kitControl
You access these data by scrolling down the ElectricalDemandLimit property sheet.
| Data item | Description |
|---|---|
| This Month Demand Period(n) Peaks | Displays the value of the highest demand (minute) so far in the current month. |
| This Month Demand Period(n) Peak Times | Displays the time and date that the current month’s peak demand occurred. |
| Previous Month Demand Period(n) Peaks | Displays the value of the highest demand (minute) that occurred in the previous month. |
| Previous Month Demand Period(n) Peak Times | Displays the time and date that the previous month’s peak demand occurred. |
| Projected Demand Average | Totals the value of the Power Input every time this value changes, and once a minute calculates Projected Demand Average and Shed Level. The component averages a combination of projected and historical samplings over the specified interval. To influence the value of the Projected Demand Average, configure the Demand Interval and the Percent Interval Elapsed properties. |
| Max Shed Level | Displays the maximum shed level used in the current month. |