3-Phase T-Type Voltage Source Inverter

Purpose

3-phase T-type voltage source inverter with filter inductors

Library

Electrical / Nanostep

Description

This component implements a 3-phase 3-level T-type voltage source inverter. It includes filter inductors on the AC side. In the model, the DC side and the AC side are electrically isolated from each other. Any electrical connection between the two sides outside the inverter would therefore not reflect the real current and voltage situation and should be avoided. The converter offers two configurations:

Sub-cycle average

The gate input is a floating-point number with values between 0 and 1 representing the relative on-time of the controlled semiconductor over one simulation step. This technique is suited for real-time simulation on a CPU or a FlexArray solver.

Nanostep / Switched

The converter is simulated with time steps in the single-digit nanosecond range. The required Nanostep solver is available exclusively on the RT Box. Both sides of the converter have current source behavior and must each be connected directly to capacitors or voltage sources. The implementation has a weight of 3, which means it occupies an entire Nanostep solver. For offline simulation, all power semiconductors in the converter are modeled with ideal switches. The individual switches are controlled with instantaneous logical gate signals. A switch is turned on when the corresponding gate signal is true.

Note

The Sub-cycle average and the Nanostep implementation cannot simulate a shoot-through or clamping of the DC side. Therefore, the combination of logically true gate signals in each inverter leg must never lead to a short circuit on the DC side. Also, the applied DC voltage must never become negative.

Parameters

Configuration

Allows you to chose between Sub-cycle average or Nanostep / Switched configuration.

Switch model (CPU code generation)

If the Configuration is set to Sub-cycle average, this parameter selects the switch model when CPU code is generated.

Semiconductor symbol

This setting lets you choose between IGBT and MOSFET for the symbol of the active semiconductor switch. It does not change the electrical behavior of the converter in simulation.

Neutral-point connection

Specifies if the neutral-point switches are series connected with Common collector (drain} for MOSFETs) or Common emitter (source for MOSFETs).

Inductance

A non-zero scalar or 3-element vector specifying the filter inductances, in henries (\(\mathrm{H}\)).

Winding resistance

A scalar or 3-element vector specifying the winding resistances, in ohms (\(\Omega\)).

Assertions

When set to on, the block will flag an error if a combination of gate signals being logically true would short-circuit any of the DC link voltages.

Nanostep Probe Signals

See Fig. 251 for the probe signal positions.

Fig. 251 Probes for the 3-Phase T-Type Voltage Source Inverter

DC currents

The currents flowing into the DC side terminals of the converter.

Inductor currents

The currents flowing out of the inverter.

Gate signals phase a

The gate signals of the active semiconductor switches of phase a.

Gate signals phase b

The gate signals of the active semiconductor switches of phase b.

Gate signals phase c

The gate signals of the active semiconductor switches of phase c.