The 3-Level NPC Converter (Switching Devices) component is a three-phase power converter model developed from IGBT and diode elements. The converter is modeled with GTO/diode pairs controlled by firing pulses produced by a PWM generator. Normally used with time steps of 100 to 200 times smaller than the period of the carrier of the PWM generator, this component provides precise off-line simulation results.

NOTE: In order to obtain accurate results, the option Activate iterative method 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'}
Diode on-state resistance	Internal resistance of the internal GTO/diodes	Ohm	Rclose = { [1e-12, 1e12] }
Diode snubber resistance	Snubber resistance of the internal GTO/diodes	Ohm	Rsnubber = { [1e-12, 1e12] }
Diode snubber capacitance	Capacitance of the internal GTO/diodes	F	Csnubber = { [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 symbol + shows that this is the positive end (supports only 1-phase connections)
DCminus	Network connector on the DC side. The symbol - shows that this is the negative end (supports only 1-phase connections)
DCneutral	Neutral network connector (supports only 1-phase connections)

Inputs

Name	Description
P	Vectorized signal containing twelve firing pulses to control the converter

Outputs

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

Sensors

Name	Description	Unit
P1	Gating signal controlling Q1.
P2	Gating signal controlling Q2.
P3	Gating signal controlling Q3.
P4	Gating signal controlling Q4.
P5	Gating signal controlling Q5.
P6	Gating signal controlling Q6.
P7	Gating signal controlling Q7.
P8	Gating signal controlling Q8.
P9	Gating signal controlling Q9.
P10	Gating signal controlling Q10.
P11	Gating signal controlling Q11.
P12	Gating signal controlling Q12.
Va	Voltage signal of phase A on the AC side of the converter.	V
Vb	Voltage signal of phase B on the AC side of the converter.
Vc	Voltage signal of phase C on the AC side of the converter.
Vdc	Converter DC link voltage signal.
Ia	Phase A current signal on the AC side.	A
Ib	Phase B current signal on the AC side.
Ic	Phase C current signal on the AC side.
Idc	Current signal of the DC link.

Additional Information

The converter is modeled by 12 IGBT/diodes controlled by firing pulses produced by a PWM generator. The figure below shows the internal circuit of the 3-Level NPC Converter (Switching Devices) using IGBT and diode elements.

The PWM generator outputs a vectorized gating signal to control the converter. The gating signal contains 12 firing pulses. The first four pulses control the Q1 to Q4 switching devices (phase A of the converter), pulses five to eight control the Q5 to Q8 switching devices (phase B of the converter), and the last four pulses control the Q9 to Q12 switching devices (phase C of the converter).

Limitations

This component must be used with the PWM Generator for 3-Level Converter (Switching Devices) component available in the Control Sources library of HYPERSIM or with an input FPGA module (contact our technical support for an example).

This model does not participate in the load flow solution.

References

MathWorks, Three-Level NPC Converter Mathworks.com. https://www.mathworks.com/help/physmod/sps/powersys/ref/pvarray.html

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

HYPERSIM Documentation

3-Level NPC Converter (Switching Devices)