MicroLogic Active E Energy Metering

Presentation

The MicroLogic Active E control unit calculates the different types of energy using energy meters and provides the values of:

• The total active energy Ep, the active energy delivered (into the load) Epdelivered, and the active energy received (out of the load) Epreceived

• The total reactive energy Eq, the reactive energy delivered (into the load) Eqdelivered, and the reactive energy received (out of the load) Eqreceived

• The total apparent energy Es

The energy values are calculated every second, and shown as an hourly consumption. Values are stored in non-volatile memory every hour.

A resettable counter is available for each energy meter.

Principle of Energy Calculation

By definition energy is the integration of the real-time power over a period T. The integration period T lasts for a number of cycles equal to the rated frequency.

Partial Energy Meters

For each type of energy, active or reactive, a partial received energy meter and a partial delivered energy meter calculate the accumulated energy by incrementing once a second:

• Delivered energy is always counted positively.

  Edelivered(t) = Edelivered(t - 1) + (Gdelivered(t))/3600

  where Gdelivered = Ptot or Qtot > 0

• Received energy is always counted negatively.

  Ereceived(t) = Ereceived(t - 1) + (|Greceived(t)|)/3600

  where Greceived = Ptot or Qtot < 0

Energy Meters

From the partial energy meters and for each type of energy, active or reactive, an energy meter provides either of the following measurements once a second:

• The absolute energy, by adding the received and delivered energies together. The energy accumulation mode is absolute.

  

• The signed energy, by differentiating between received and delivered energies. The energy accumulation mode is signed.

  

The apparent energy Es is always counted positively.

Selecting Energy Calculation

The information sought determines calculation selection:

• The absolute value of the energy that has crossed the poles of a circuit breaker or the cables of an item of electrical equipment is relevant for maintenance of an installation.

• The signed values of the energy delivered and the energy received are required to calculate the economic cost of an item of equipment.

By default, absolute energy accumulation mode is configured.

Select the energy calculation mode on the MicroLogic Active E display screen, from the tree navigation menu, at Configuration > Measures > E calcul.

Resetting Energy Meters

The energy meters can be reset on the MicroLogic Active E display screen, from the tree navigation menu, at Measures > Energy > Reset Counters