Arrangement for specifying a pressure
Assigneeebm-papst St. Georgen GmbH & Co. KG
InventorsAlexander Hahn, Marcus Hellmann, Michael Kisch, Jens Loeffler, Manfred Bitzer
Life of this patent
Estimating the term…
Abstract
An arrangement (100) for specifying the pressure (64), produced by a pump (30) driven by an electric motor (31), includes a processor (116) which derives a target pressure value (62, 118) from an internal torque value (114) and a loss torque (108). The arrangement (100) further derives (112) the internal torque value (114) from a motor current value (110) and a motor constant ke.
Claims11
Apparatus (100) for specifying pressure (64) generated by a pump (30) driven by an electric motor (31), said apparatus comprising:
- the electric motor (31) configured to drive the pump (30);
- a source (46, 20, 16) of instantaneous fluid pressure values (64) and a pressure controller (12) coupled to an output of said source;
- a first processor (112) configured to calculate an internal torque value (114) based on a motor current value (110) and a motor constant ke;
- a second processor (116) configured to calculate a target pressure value (62) corresponding to a target pressure of the pump (30) based on a difference between said internal torque value (114) and a loss torque value (108);
- and
- a third processor (109) configured to calculate said loss torque value (108) based on a temperature value (104) and a motor RPM value (106);
- wherein a pressure difference is determined based on the difference between an instantaneous pressure of the pump and the target pressure value (62), and a motor control signal is generated that corresponds to the pressure difference to control the electric motor (31) to drive the pump (30) at the target pressure;
- and
- wherein said pressure controller (12), based upon a difference between an instantaneous fluid pressure value (64) and a target pressure value (62), generates a setpoint value (118) which influences power supplied to said motor (31), to bring said instantaneous pressure value (64) toward said target pressure value (62).
A controller for operating a pump (30) which is driven by an electric motor (31), comprising
- a speed-ramp (14) which directs motor start-up steps;
- a pressure controller (12) coupled to an output of a source of instantaneous fluid pressure values (64) and which controls post-start-up operation of the motor, said pressure controller (12) configure to calculate a target pressure value (62) corresponding to a target pressure of the pump (30) based on a difference between an internal torque value (114) as a function of a motor current value (110) and a motor constant ke and a loss torque value (108) as a function of a temperature value (104) and a motor RPM value (106);
- said pressure controller (12), based upon a difference between an instantaneous fluid pressure value (64) and a target pressure value (62), generating a setpoint value (118) which influences power supplied to said motor (31), to bring said instantaneous pressure value (64) toward said target pressure value (62);
- and
- a changeover switch (80) which determines when control of said pump is passed from said speed ramp (14), handling a start-up mode, to said pressure controller (12), handling a continuous-operation mode.
Dependencies are inferred from the claim text.