Specifications; Reactive Power Control - Kaco blueplanet 3.0TL3 Series Manual

10

Specifications

10.1

Reactive power control

Reactive power can be used in electrical energy supply networks to bolster the level of voltage. As such, feed-in inverters
can contribute to statistical voltage stability. Reactive power brings about a voltage drop at the inductive and capacitive
components of the equipment which can either bolster or reduce the level of voltage. If the generating plant draws in-
ductive reactive power while active power is being fed in, part of the voltage swing caused by the active power feed can
be compensated for by the supply of reactive power.
This reactive power mode and the respective control process are specified by the grid operator. If no control process has
been specified, then the system should be operated using a reactive power specification of 0%.
10.1.1 Operating power range depending on grid voltage
Fig. 42: P-Q operating range for devices below 12 kVA with
U 220/380, 230/400, 240/415V (Qmax=0.95Smax)
N
10.1.2 Dynamics and accuracy
In all control methods the specified target value at the inverter's connection terminals is adjusted using a stationary devi-
ation of the reactive power of maximum 2% S
power. If the shift factor cos ϕ is specified in the control method, then the deviation relates to the reactive power value
brought about by the current power level.
The transient response of the control methods is determined by a PT-1 filter. In this case, the settling time corresponds to
5 Tau, or in other words, achieving approx. 99% of the final value for a PT-1 filter. Subject to the control method selected,
there are also other parameters that determine dynamic behaviour.
10.1.3 Reactive power functions
The following functions for controlling the reactive power are implemented in the devices listed above:
ž cos φ constant
ž Q constant
ž cos φ /(p/pn)
ž Q(U) 10 nodes
ž Reactive power is prioritised in each method. The maximum possible active power that can be fed in is reduced in line
with the P-Q operating range when a specific reactive power level is specified.
cos ϕ constant
In cos-φ constant mode the specified displacement factor cos-φ is set permanently by the inverter. In doing so, the react-
ive power level is set according Q=P*tan φ dependent on power output which produces the specified displacement factor
cos-φ continuously. If the specification is changed, the new value is adopted attenuated by a filter. The transient time is 1
s with the transient response of a first-order filter (PT-1) with a time constant of Tau=200ms. The specified displacement
factor may be configured in the display or via communication, via KACO RS485 protocol and MODBUS/SunSpec.
If the applicable grid code requires the cos-φ response to set point by a defined gradient or settling time slower than the
configured Tau=200ms, this gradient or settling time must be implemented in the plant control system.
KACO blueplanet 3.0TL3 KACO blueplanet 4.0TL3 KACO blueplanet 5.0TL3 KACO blueplanet 6.5TL3 KACO blue-
planet 7.5 TL3 KACO blueplanet 8.6TL3 KACO blueplanet 9.0TL3 KACO blueplanet 10.0TL3
S [p.u. S ]
nom
1,2
1
0,8
0,6
OV
RT
0,4
0,2
0
540 500
Fig. 43: Apparent power subject to grid voltage for devices
below 12 kVA with UN 220/380, 230/400, 240/415V
. This maximum deviation always relates to the specified value as reactive
N
Over load capability
Under voltage
Nominal capability
UVRT
derating
460 420 380 340 300 260
U [V]
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