user manual

Controller

In Polysun, batteries are equipped with an automatic controller as a standard. If necessary, the battery may also be controlled by means of the available programmable controller.

The controller works based on a calculation of the system’s net power \(P_{n}(t) = \ I_{generated} – I_{consumed}\), with I= power.

Automatic controllers work on this basic principle: the battery is charged when enough self-generated power is available and discharged as soon as a power deficit occurs. It is never charged from the grid, unless under one of the following conditions:

• The battery’s state of charge falls below an SOE_H2 threshold (-0.05 by default). In this case, boost charging occurs with 0.25 times the nominal charging power, until the battery reaches its minimum state of charge. A common cause of this case is a high self-discharge or high peripheral consumption in combination with long periods without charging.
• The battery peripherals’ or battery inverter’s AC consumption is not met by the electricity production.
• The battery’s stationary control deviation is not met by the electricity production.

Description of an automatic controller:

1. When the system generates an amount of power in excess of what is consumed  (P_n(t) > 0) the following charge pattern applies:
   1. Charge battery with maximum possible, available power as long as it can be charged.
      Pch(t)=min[Pnt, Pch,maxt]
   2. Feed remaining power into the grid.
      Ptegt=Pnt-Pcht
2. When the system consumes more power than it generates (P_n(t) < 0) the following discharge pattern applies:
   1. Discharge battery to maximum possible extent as long as it can be discharged.
      Pdis(t)=min[|Pnt|, Pdis,maxt]
   2. Draw the remaining power from the grid.
      Pfegt=Pnt+Pdist

The battery offers two inputs for the programmable controller:

Table: Input parameters for the programmable controller

Input	Description	Value
Control mode	Shows how the battery is controlled	0: automatic controller (default value) 1: controlled battery power is used
Controlled power	Battery power may be set.	> 0: the battery is charged, value in W <= 0: the battery is discharged, value in W

Template 50h provides an example of explicit battery control.