DH-1220 Load control requests

General information about load control requests

The load control service provider submits a load control request to Datahub, which forwards the request to the DSO of the accounting point. The DSO returns a confirmation of the execution of the load control to Datahub once the requested control has been programmed into the meter for execution or otherwise processed. Datahub then forwards the confirmation to the load control service provider who made the original request.

There are no uniform and precise requirements for the load control capability of remotely controllable electricity meters, which means that the capabilities of meters produced by different manufacturers or used by different network operators may vary somewhat. The load control events described in this chapter aim to establish compromises that, from the perspective of the load control service provider, operate on the same principles at all accounting points capable of relay‑based load control.

Legislation sets a maximum processing time of six hours for load control requests. However, DSOs generally aim to process requests as they arrive, and under normal conditions the actual processing time can be expected to be significantly shorter than the maximum. In exceptional situations, such as communication disturbances, processing may be considerably slower. In such cases, the DSO will typically attempt to program the received request to the meter multiple times.

Three different types of load control request events have been defined, each with a slightly different purpose. The different event types and their main intended uses are listed in the table below. The event types are based on the classification presented in the measurement decree (mittausasetus). The model based on a base calendar, combined with shorter‑term controls that deviate from it, protects the customer in potential disturbance situations, meets the needs identified in previous analyses, and is practically implementable with most of the currently installed meters. For every load control request, Datahub returns an acknowledgement indicating whether the request has been accepted for forwarding to the DSO or not.

Each accounting point capable of load control may have either one or two controllable relays. If the accounting point has only one controllable relay, the DSO may report to Datahub which relay can be controlled. If the accounting point has two controllable relays, the load control service provider agrees with the customer which relay the service provider will control. It is not permitted to control both relays through the load control interface; the interface allows the control of only one relay. An exception to this is a situation where the load control service provider has not received information from the customer on whether relay 1 or relay 2 should be controlled. In such cases, it may be necessary to control both relays alternately to determine the correct one. After clarification, only the relay identified as correct must be controlled.

The control command included in the control request specifically controls the meter’s load control relay. The customer is responsible for arranging the connection of the controllable loads, and therefore the impact of the relay state on the controllable loads may vary depending on the customer and the accounting point. Typically, loads are connected so that when the relay is in the closed state, the controllable loads are switched on, and correspondingly when the relay is in the open state, the controllable loads are switched off. However, the load control service provider should verify with the customer how the controllable loads have been connected. If necessary, this can also be determined through test control requests in the same way as when verifying the correct relay.

The DSO generates the load control confirmation once the load control request has been transferred to the metering system or to the meter at the accounting point. Under normal conditions, the confirmation should reach the load control service provider relatively soon after the load control request has been submitted. In exceptional circumstances, the delay may be longer, and the service provider must not send a new request to the same accounting point before the six‑hour time limit has passed or before receiving the load control confirmation. This is because when multiple simultaneous requests are targeted at the same accounting point, the DSO’s systems may not always guarantee their processing order, which can lead to unexpected control outcomes.

Currently, relay‑based controls often include a random delay directly configured into the meter when switching load on. The purpose of this delay is to reduce momentary load peaks, especially when night‑time electricity switches on. In market‑based load control, however, such delays may significantly worsen the end‑customer experience. For this reason, it is recommended that when an accounting point transitions to market‑based load control service provided by a load control service provider, the random delay should be removed.

Types of load control requests

Load control request for calendar control

The load control service provider submits a request for calendar‑based load control at the customer’s accounting point through the event DH-1221. A calendar‑based load control request is created for a period of one week, making it well suited for similarly recurring control patterns. The meter automatically repeats the control periods contained in the request in the same way each week, until a new control calendar is programmed into the meter. Updated calendar‑based control requests can be sent as needed; however, unnecessary requests should be avoided. If the need for updates is very frequent (e.g., daily or nearly daily), the use of scheduled controls should be considered. The content of the request is forwarded to the DSO of the accounting point.

When starting the customer’s load control service, the load control service provider is required to create a calendar‑based load control request for the accounting point to ensure that the base calendar programmed into the meter is suitable for the customer’s load control needs. The service provider must also update the calendar upon receiving information that the accounting point’s meter has been replaced or that some other event has removed the programming from the meter, provided that the DSO has not restored the previous base calendar. A calendar update is also required if a load control authorization that has (incorrectly) ended or been cancelled is restored retroactively, since the DSO may have removed the meter’s programming due to the termination or cancellation of the authorization. At the same time, any scheduled control request for the following day must also be resent. The base calendar may also be updated during the service if needed.

When the load control service provider changes or when market‑based load control ends at the accounting point, the previous base calendar remains in effect until the next party providing the service updates a new base calendar for the customer. If responsibility shifts to the next load control service provider, that provider must request calendar‑based load control as described above. If responsibility shifts to the DSO, the DSO programs the base calendar into the meter according to its own internal processes.

The purpose of the base calendar is to ensure the functioning of the customer’s relay‑controlled electrical devices in potential communication disturbance situations. For example, the heating of an entire building may be dependent on relay control, and an unintended, prolonged outage could cause significant harm to the customer. For this reason, setting a base calendar is essential, even if the service provider does not otherwise plan to use calendar‑based control. The base calendar serves this purpose best when it contains at least one “off” and one “on” period. If the base calendar contains only a single control period that does not result in any control actions on the meter, the customer’s relay‑controlled electrical equipment may remain incorrectly switched off for extended periods in disturbance situations.

If the customer’s meter must be replaced or if its base calendar is otherwise lost during market‑based load control due to actions taken by the DSO, the DSO may restore the base calendar previously sent by the load control service provider. If the DSO does not restore the service provider’s base calendar itself, it must notify the service provider as soon as possible of the need to create a new calendar‑based load control request for the accounting point. If the DSO restores the base calendar itself, no notification is required. There is no Datahub event for this notification; the DSO must inform the service provider directly. Datahub provides an email template for this notification.

A new calendar‑based load control request may be submitted once a confirmation has been received from the DSO for the previous calendar‑based request for the same accounting point.

Load control request for scheduled control

The load control service provider submits a request for scheduled load control at the customer’s accounting point via the event DH-1222. The control applies to the following day and is a one‑time action in nature. The request must cover the entire following day. The content of the request is forwarded to the DSO of the accounting point.

Before submitting a scheduled load control request for an accounting point, the load control service provider must have submitted an approved calendar‑based load control request for the same accounting point. This ensures the proper operation of the customer’s relay‑controlled electrical devices in potential communication disturbance situations. Datahub does not perform this check; instead, it is the responsibility of the load control service provider to ensure that the correct operating model is followed.

Load control request for single control

The load control service provider submits a request for single load control at the customer’s accounting point through the event DH-1223. The control is executed as soon as possible and remains in effect until the next pre‑programmed control action is carried out, or until another single control request is submitted. After sending the request, the load control service provider must wait for the load control confirmation sent by the DSO before sending the next single control request for the same accounting point. When sending single control requests, the service provider must ensure that the relay state at the accounting point changes no more than six times per day. Datahub does not technically limit the number of messages; instead, the service provider is responsible for monitoring the volume of requests. The content of the request is forwarded to the DSO of the accounting point.

The DSO must check the timestamp of the received message before executing the load control request. In exceptional situations, the message may have been delayed to such an extent that executing it may no longer be reasonable. If the timestamp of the message is more than six hours old, the DSO must send a negative confirmation for the request, and the load control request must not be executed.