Power factor (reactive power)

What this step does

The row appears when the Model tab's Power factor step is set to Own row and the power factor is below 1. The inverter pass runs a second time at a power factor of 1 when the inverter's nominal power is an apparent power, and the AC chain is computed a second time at a power factor of 1 on the same inverter output. The clipping row, the inverter output and each resistive AC row then show their values at a power factor of 1, and this row takes the difference. The energy injected into the grid is the same as with the cost inside the other rows.

The math

1. Running total
2. Loss at a timestep

$$E_{after} = E_{before} - E_{row},\qquad E_{row} = \frac{\Delta t}{1000\,P_{DC}}\sum_i L_i \tag{1}$$ $$L_i = N_{inv}\left(P_{out,1,i} - P_{out,i}\right) + \sum_r \left(L_{r,i} - L_{r,1,i}\right) \tag{2}$$

where

Symbol	Meaning	Unit
$E_{before}$	the running total of the loss diagram before this row	kWh/kWp
$E_{after}$	the running total after this row	kWh/kWp
$E_{row}$	the row taken as a loss	kWh/kWp
$\Delta t$	the length of one timestep	hours
$P_{DC}$	the DC nameplate of the system	kWp
$L_i$	the power lost at timestep $i$ over the whole system	W
$N_{inv}$	the number of inverters	—
$P_{out,1,i}$	the output of one inverter at timestep $i$ with a power factor of 1, in W; equal to $P_{out,i}$ when the nominal power is an active power	—
$P_{out,i}$	the output of one inverter at timestep $i$	W
$L_{r,i}$	the loss of resistive AC row $r$ at timestep $i$	W
$L_{r,1,i}$	the same loss at a power factor of 1	W

Reading the number

A loss, negative. Zero at a power factor of 1. The resistive share is 1/PF² − 1 of the resistive AC losses at a power factor of 1, 23 % of them at 0.9. The inverter share needs an apparent-power nominal and grows with the hours the inverter clips. On the default request at 0.9 with an apparent-power nominal the row is 0.3 % of the inverter output.

API

loss.power_factor

Symbols follow the symbol registry.