System and method for producing a liquefied hydrocarbon stream and method of operating a compressor

At least part of a fluid (210,110) is compressed in a compressor (120,220) driven by an electric motor (130,230). The compressor has variable inlet guide vanes of which an angle can be adjusted. The electric motor is powered using a power supply network (400), and a signal representative of a condition of the power supply network is monitored. From the signal, it is automatically determined whether additional load shedding is needed, by comparing the signal to a predetermined criterion. The variable inlet guide vanes angle is automatically adjusted when the criterion is satisfied and additional load shedding is needed. This automatically reduces the loading of the compressor. The compressor and the method of operating it may be employed as part of a system for producing a liquefied hydrocarbon stream (90) and/or in the course of producing a liquefied hydrocarbon stream (90), in which case the compressor can be a refrigerant compressor and the fluid a refrigerant fluid.