Most such converters rely on the inductance of the motor windings for proper operation, they wont work with a resistive load. Also, 3 phase motors are very tolerant of poor supply voltages and will often give acceptable service with unbalanced voltages and incorrect phase angles, the motor may need to be oversized relative to the mechanical load to avoid overheating.

Most such converters produce three phase THREE wire without a neutral, and with about 230 volts between phases, not 400 volts between phases as would be obtained from a standard UK mains supply.

To obtain a good simulation of a true three phase, 4 wire mains supply may need a 3 phase generator, driven by a single phase motor. The generator wont "know" that it is being driven by an electric motor rather than by a petrol or diesel engine.

It is also possible to obtain 3 phase supply from a bank of three single phase inverters under common control, this is done in premises without utility service. These inverters require DC input at 12 volts, 24 volts, or 48 volts nominal, or less commonly at 110/120 volts dc.

Both the above are expensive and complex.

BTW, the standard uk supply at 230 volts for domestic and similar purposes is called single phase 2 wire. Single phase 3 wire implies a centre tapped supply as used in the USA  at 120/240 volts.

Have you looked at Transwave?

Transwave - Home

Most such converters rely on the inductance of the motor windings for proper operation

Undoubtely true for motor drives. In theory that that need not be the case though - there are plenty of general purpose inverters out there - e.g. for PV or battery sources (both grid-tried and off-grid) or UPSs - that are perfectly capable to driving arbitrary loads. I can't think of a single unit unit I've come across that includes a rectifier first stage in the same unit though (i.e. single phase mains -> d.c. -> 3-phase a.c.) (at least without a batter, making it a UPS), even though it seems to be entirely feasible technically.  Maybe it's just economics - it's probably cheaper to "right size" inverter drives on a few machines that really need 3-phase than to make a large unit that would have to cope with possibly large demands of a workshop and be underutilized 99% of the time. Even less so for a demo project.

   - Andy.