Process and device for flow control of an electrical motor fan

A configuration for flow control of a fan (3), which is powered by an electric motor (2), specifically for maintenance of a constant flow from a fan having a rotor and a filter (4) positioned on a suction side of the fan, characterized in that a control unit (12) is connected to the motor, the control unit controls the voltage supply to the electric motor;

• a first sensor (26) is connected to the control unit (12), with the aid of which the actual value of the motor's power consumption is determined;
• a second sensor (30) comprised in the motor to indicate the position of the rotor, with the aid of which the motort's actual speed is determined;
• a memory (14) in which at least one curve (A, B) or a table is stored, which states the correlation between the speed and power consumption of the motor (2) at a given flow at the fan (3);
• and a comparison means in the control unit set to compare both the motor's actual speed and the motor's power consumption with a selected flow curve from the memory and in the event of any deviation of the motor's actual speed and the motor's power consumption to control the voltage supply to the motor so that the deviation is reduced.

A flow control for a fan, said fan being powered by an electric motor having a rotor, comprising:

• a control unit operatively coupled to said electric motor, said control unit controlling a voltage supply to said motor;
• a first sensor sensing a parameter from which a power consumption of said electric motor is determined;
• a second sensor sensing a parameter indicative of a position of said rotor from which an actual speed of said electric motor is determined;
• a memory in which is stored values representative of a correlation between said actual speed of said electric motor and said power consumption of said motor at a given flow rate at said fan;
• and
• a comparator operatively coupled to said memory for comparing said power consumption and said actual speed of said electric motor with said stored values from said memory representative of a selected flow rate;
• said control unit operative to control said voltage supply to said motor to reduce any deviation between said power consumption and said actual speed and said stored values from said memory representative of said selected flow rate.