The 2-level converter (Average) non-rectifier mode can be used in applications such as the integration of renewable energy sources and motor drives. It models a three-phase power converter of the VSC (Voltage Source Converter) type. This converter is modeled using a switching function model directly controlled by the reference voltage so that a PWM generator is not required. In addition the rectifier mode is not simulated.

NOTE: In order to obtain accurate results, the options Activate iterative method and Solve control inputs before solving power in Simulation Settings must be selected when using this component.

Mask and Parameters

Parameter Name	Description	Unit	Variable = {Possible Values}
Description	Use this field to add all kinds of information about the component		Description = {'string'}
AC voltage source resistance	Internal resistance of the AC voltage sources	Ohm	Rac = { [1e-12, 1e12] }
DC current source parallel resistance	Internal resistance in parallel with the DC current source	Ohm	Rdc = { [1e-12, 1e12] }

Ports, Inputs, Outputs and Signals Available for Monitoring

Ports

Name	Description
net_1	Network connector on the AC side (supports only 3-phase connections)
DCplus	Network connector on the DC side. The + sign indicates this is the positive end (supports only 1-phase connections)
DCminus	Network connector on the DC side. The - sign indicates this is the negative end (supports only 1-phase connections)

Inputs

Name	Description
Vref	Vectorized signal containing three reference voltages to control the converter.

Outputs

Name	Description
V	Vectorized voltage signal containing the phase-ground voltage of the AC side (Va, Vb and Vc) and the DC link (Vdc).
I	Vectorized current signal containing the phase-ground current of the AC side (Ia, Ib and Ic) and the current of the DC link (Idc).

Sensors

Name	Description	Unit
Vref[Va]	Phase-ground reference voltage signal for controlling AC source in phase A.	p.u.
Vref[Vb]	Phase-ground reference voltage signal for controlling AC source in phase B.
Vref[Vc]	Phase-ground reference voltage signal for controlling AC source in phase C.
V[Va]	Voltage signal of phase A from the AC side of the converter.	V
V[Vb]	Voltage signal of phase B from the AC side of the converter.
V[Vc]	Voltage signal of phase C from the AC side of the converter.
V[Vdc]	Voltage signal from the DC link of the converter.
I[Ia]	Current signal of phase A from the AC side.	A
I[Ib]	Current signal of phase B from the AC side.
I[Ic]	Current signal of phase C from the AC side.
I[Idc]	Current signal of DC link.

Additional Information

The converter is modeled by a switching function model. The switches are replaced by three voltage sources per phase on the AC side and a current source on the DC side.

The figure below shows the internal circuit of the converter. Although the topology of the converter is similar to that of the Full-bridge converter (Switching Function), the equations for controlling the amplitude of voltage and current sources are different.

The converter is directly controlled by the reference voltage so that a PWM generator is not required. In addition the rectifying operations are not simulated.

Limitations

This model does not participate in the load flow solution.

References

MathWorks, Two-Level Converter Mathworks.com. https://www.mathworks.com/help/physmod/sps/powersys/ref/twolevelconverter.html

M. H. Rashid, Power electronics handbook, 4^th ed. Butterworth-Heinemann, 2017

See Also

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