CPC F04C 25/02 (2013.01) [F04B 35/04 (2013.01); F04B 37/14 (2013.01); F04B 49/065 (2013.01); F04C 28/06 (2013.01); F04C 28/08 (2013.01); F04D 19/04 (2013.01); F04D 27/001 (2013.01); F04D 27/004 (2013.01); F04D 27/0261 (2013.01); F04B 2203/0209 (2013.01); F04C 2220/10 (2013.01); F04C 2270/051 (2013.01); F04C 2270/23 (2013.01); F05D 2270/3011 (2013.01)] | 17 Claims |
1. A method for controlling a speed of a Variable Speed Drive, (VSD) vacuum pump employed in a cyclic application, comprising:
controlling the pump to operate in repeated cycles, each cycle comprising a pump down phase and a holding phase, wherein each cycle starts at a time point when a rise in an inlet pressure of the pump reaches a preset threshold and the time between two consecutive cycle starts is a cycle time;
determining, during a present cycle, a start of a next cycle, wherein the present cycle directly precedes the next cycle;
estimating pre-speeding time of the next cycle based on an estimation of the pre-speeding time determined for the present cycle and an observation of the pre-speeding time of the present cycle, each pre-speeding time referring to a length of time since a respective start of a respective cycle until a time point in the holding phase of the respective cycle when the pump is controlled to speed up; and
controlling the pump to speed up to a maximum speed during the holding phase of the next cycle at the end of the estimate of the pre-speeding time of the next cycle before the start of a cycle after the next cycle such that at the start of the cycle after the next cycle full pump capacity is available.
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