370w = 1/2 hp
Convertor or Inverter?
My Teco 2hp inverters will quite happily run something like this.
Have you checked it's not still wired star 415v
You could run it (at around 60% power) just using capacitors there are many guides on the net how to do this, basically 2 capacitors one to start and one to run the start one is switched out once the motor reaches speed.
The values of the capacitors you will have to calculate using the motors parameters against your chosen formulae/values.
Optimum capacitor value varies with motor design and load popular (but by no means comprehensive) Capacitor values for a 370w motor might be:
Run Cap 20 uf
Start Cap x2 run capacitor value for light loads and 3 to 8 times as load increases.
Start cap normally switched in and out using a potential relay or a timer (you could do this manually).
The workshop practice series has a few very good volumes on using three phase equipment on single phase, I use a mixed bag of inverters, homemade converters and a homemade rotary convertor.
Regards
Paul
(Disclaimer: Please do not attempt any of the above unless you are competent/trained)