Frequency-doubling LLC Converter

Purpose

Frequency-doubling resonant LLC converter with synchronous rectification

Library

Electrical / Nanostep

Description

../../_images/nanostep_fd_llc.svg

This component implements an isolated, resonant LLC converter. The input side is modeled as two series-connected half-bridges and the output side as a half-bridge rectifier with synchronous rectification.

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 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 voltage sources connected to the converter must not be short-circuited. Therefore, combinations of switching signals that cause shoot-through of the primary-side DC links are not permitted. Additionally, the DC voltage across a half-bridge must never become negative.

Parameters

Leakage inductance

A non-zero scalar specifying the primary side leakage inductance of the transformer, in henries \((\mathrm{H})\).

Winding resistance

A scalar specifying the resistance of the primary winding, in ohms \((\Omega)\).

Resonant capacitance

A non-zero scalar for the resonant capacitance, in farads \((\mathrm{F})\).

Magnetizing inductance

A non-zero scalar specifying the magnetizing inductance of the transformer, referred to the primary side, in henries \((\mathrm{H})\).

Turns ratio

A scalar specifying the ratio of primary-side turns to secondary-side turns.

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.

Probe Signals

Inductor current

The current flowing into the primary side of the transformer.

Magnetizing current

The current through the magnetizing inductor, referred to the primary side.

Capacitor voltage

The voltage across the resonant capacitor.

Nanostep Probe Signals

See Fig. 262 for the Nanostep probe signal positions.

Inductor current

The current flowing into the primary side of the transformer.

Magnetizing current

The current through the magnetizing inductor, referred to the primary side.

Primary currents

A vector containing the currents flowing from the primary DC links into the converter.

Secondary current

The current flowing from the secondary DC link into the converter.

Capacitor voltage

The voltage across the resonant capacitor.

Primary gate signals

A vector containing the gate signals of the primary side semiconductor switches.

Secondary gate signals

A vector containing the gate signals of the secondary side semiconductor switches.

../../_images/nanostep_fd_llc_probe_signals.svg

Fig. 262 Nanostep Probe Signals for the Frequency-doubling LLC Converter