2 phase Square Wave Inverter

[adi1893]

I am using a Teensy 4.1 to make a power supply that has a DC Bus that then goes to a 2 phase Square Wave AC Inverter that uses 4 IGBTs. Already using a FlexPWM instance (Teensy_PWM library) for the single IGBT for the DC Bus but require help for the Inverter stage.

Require two individual outputs in the following sequence:

1. Out1: On for around 3100us

2. Outputs off for a fixed deadband (somewhere between 400ns to 4us)

3. Out2: On for around 3100us

4. Outputs off for fixed deadband as before

Requirement will be somewhere between 100Hz to 200Hz (full cycle) with 0.4 to 4us deadband. Frequency and deadband will be fixed.

Require a hardware PWM solution as going through IntervalTimer interrupt will clash with other interrupts that I am using for analog reading that end up taking more than 5-10us (much longer than the 0.4us to 4us deadtime)

Any help for using a hardware PWM library for this application would be much appreciated! All the forum posts and examples are for 3 phase sine inverter outputs, nothing for 2 phase simple square wave with fixed frequency and deadband.

TIA

 

[MarkT]

Why not use a suitable H-bridge driver chip - many advantages that way, like undervoltage lockout, programmable deadtime etc. Then standard PWM can be used.
The HIP4081A has too short a deadtime, but I'm sure there's something else suitable out there, perhaps specific for IGBTs (which have somewhat different requirements from MOSFETs).

 

[adi1893]

Why not use a suitable H-bridge driver chip - many advantages that way, like undervoltage lockout, programmable deadtime etc. Then standard PWM can be used.
The HIP4081A has too short a deadtime, but I'm sure there's something else suitable out there, perhaps specific for IGBTs (which have somewhat different requirements from MOSFETs).

I'll probably use something like a UC3525A or something similar to what you mentioned if I can't get a good solution from the Teensy itself as all the circuitry is already manufactured. Using a good driver ic already for each individual IGBT with protection built in, HCPL 316J.