4-Phase Voltage Source Inverter

Purpose

4-phase voltage source inverter with filter inductors

Library

Electrical / Nanostep

Description

This component implements a 4-phase voltage source inverter (VSI). It includes three filter inductors on the AC side phases. The fourth phase is without filter inductor and is typically connected to the neutral point of the AC system. 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. In this configuration, the DC and AC sides are galvanically isolated. Any electrical connection between the two sides outside the component would therefore not reflect the real current and voltage situation and should be avoided. Both sides of the converter have current source behavior and must each be connected directly to a capacitor or a voltage source. 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 gate signals for the upper and lower switch in each leg must never both become true at the same time. 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.

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 flags an error for combinations of gate signals that cause shoot-through. When set to off, these errors are not checked during real-time simulation.

Nanostep Probe Signals

See Fig. 253 for the Nanostep probe signal positions.

DC link current

The current flowing into the DC side terminal of the converter.

Inductor currents

A vector containing the abc-phase currents flowing out of the converter.

Neutral-point current

The d-phase current flowing out of the converter

Gate signals

A vector for each phase containing the gate signals of the semiconductor switches.

Fig. 253 Nanostep Probes for the 4-Phase Voltage Source Inverter