TYPE 75: ELECTRIC CONVERTER

General Description

This subroutine models a DC/AC inverter and a DC/DC converter after /1/.

Nomenclature

mode - 1 = Connected to the electric power net 2 = Connected to a load

Z - Power efficiency of the converter or inverter

P_n - Characteristic output power for one module

P - Power ; mode = 1 : Input power known, mode = 2 : Output power known

P_0pn - Idling constant for a converter or inverter module (P_0pn = P₀/P_n, P₀ [W] power loss when there is a voltage over the inverter or converter)

U_s - Set voltage for a module

R_ipn - Inner resistance constant for a Module of converter or inverter (Ripn = Ri*Pn, Ri [Ohm] Inner resistance for a module)

mp - Number of parallel connected modules

U_in - Voltage in to the converter or inverter

U_out - Voltage out of the converter or inverter

I_out - Current out of the converter or inverter

P_out - Power out of the converter or inverter

I_in - Current in to the converter or inverter

P_in - Power in to the converter or inverter

P_loss - The power loss in the converter or inverter

Mathematical Description

The power loss for both modes is calculated with this equation:

The inverter/converter can have either output or input power as input for the calculations (output if the system is connected to a load or input if the system is connected to the electric power net).

The converter/inverter is disconnected when the input voltage, output voltage or power is zero.

TRNSYS Component Configuration

PARAMETER NO. DESCRIPTION

1: mode - 1 = Connected to the electric power net 2 = Connected to a load

2: P_n - Characteristic output power for one module

3: P_0pn - Idling constant for a converter or inverter module (P_0pn = P₀/P_n, P₀ [W] power loss when there is a voltage over the inverter or converter)

4: U_s - Set voltage for a module

5: R_ipn - Inner resistance constant for a Module of converter or inverter (Ripn = Ri*pn, Ri [Ohm] Inner resistance for a module)

INPUT NO. DESCRIPTION

1: U_in - Voltage in to the converter or inverter

2: U_out - Voltage out of the converter or inverter

3: P - Power ; mode = 1 : Input power known, mode = 2 : Output power known

4: mp - Number of parallel connected modules

OUTPUT NO. DESCRIPTION

1: U_out - Voltage out of the converter or inverter

2: I_out - Current out of the converter or inverter

3: P_out - Power out of the converter or inverter

4: Z - Power efficiency of the converter or inverter

5: U_in - Voltage in to the converter or inverter

6: I_in - Current in to the converter or inverter

7: P_in - Power in to the converter or inverter

8: P_loss - The power loss in the converter or inverter

Informational Flow Diagrams

References

/1/ Hermann Laukamp, Wechselrichter f9r Photovoltaik-Anlagen, FhG-ISE Freiburg, 1988.