Method of regulating electrical supply for a magnetic bearing control system

A method of regulating a DC/DC voltage converter (108, 112), configured as an electrical supply for a magnetic bearing control system (111), the method comprising the steps of:

• converting an input DC voltage from the DC/DC voltage converter (108, 112) to an output DC voltage, suitable as the electrical supply;
• powering the magnetic bearing control system (111) with the output DC voltage, thereby generating an output DC current when active;
• and
• monitoring the output DC current;
• wherein the method further comprises the steps of:
• determining a time-dependent critical temperature (500), indicative of a margin to an overheating limit of the DC/DC voltage converter (108, 112) on the basis of a thermal model thereof, the thermal model comprising one or more of the group of:
• a heat loss parameter, indicative of thermal losses of the DC/DC voltage converter (108, 112) when active;
• a cooling capacity parameter, indicative of an active and/or passive cooling power of the DC/DC voltage converter (108, 112);
• and
• an equilibrium current, indicative of a thermal equilibrium of the DC/DC voltage converter (108, 112) when the output DC current is equal thereto
• determining, on the basis of the critical temperature (500), a time-dependent current saturation limit (502) over a predefined time period, the current saturation limit (502) being indicative of a warming-up of the DC/DC voltage converter (108, 112) over this predefined time period, thereby obtaining a time-dependent limit value for the output DC current;
• and
• when the output DC current exceeds the time-dependent limit value, the method further comprises the step of:
• limiting the output DC current to the limit value.