Ablerex EnerSalvys AB-ESSINV, User Manual, Page: 71 / 89

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3-4. Control Mode Description
3-4-1. Self-Consumption Control
The self-consumption control mode uses ESS-MET to measure the purchase/feed-in energy
power of the PCC( Point of common coupling ) , and feedback this power to the controller; when the
power measured at the responsibility demarcation point is positive, it is purchasing energy, and if
the measured power is negative, it is feeding-in energy. The main concept is that if the battery
capacity is sufficient during energy purchase, then discharge for the load to use in order to lower
the energy purchase ratio; if the battery was not fully charged during energy feed-in, then save the
feed-in power into the battery.
Feed-in power behaviors of the ESS system that can be set by the user in the self-consumption
mode are as follows:
1. Do not allow feed-in.
2. Allow feed-in.
3. Allow feed-in but limited the feed-in power (set by user).
The Figures 3-A, 3-B and 3-C below is the solar power generation curve and load curve for a
day. Assume that the battery capacity was in the depleted status at first, from 0:00am to 6:00am,
there is load consumption. therefore,
ESS-MET measured that it was in the purchase electricity
status within this period. However, since the battery was depleted, it therefore was unable to
execute the discharge function.
When the time reached the 6:00am to 9:00am period, although the solar power gradually
increased at first, it was still not enough to provide all load power.Therefore, the solar power and
utility grid provided the load power together.
When the time reached the 9:00am to 16:00pm period, the solar power generation power is
larger than the load requirement, so the excess solar power will be processed according to the
feed-in power setting set by the user.
1. When the user set it as “
do not allow feed-in, as shown in Figure 3-A, the excessive solar
power will first charge the battery.The charging current will be adjusted according to the battery
capacity. When the battery is fully charged or that the charging power was not enough to
absorb all the solar power, the inverter will limit the output power until the feed-in power of the
utility grid is zero.
2. When the user set it as “ allow feed-in” , as shown in Figure 3-B, the excessive solar power will