Patent ID: 8297938
Filing Date: 2012-10-30
Classification: F04B,H02P

Abstract:
1. System for controlling a linear compressor comprising: a linear motor that drives the reciprocating motion of a piston ( a position-detecting circuit which generates a displacement signal (SD) indicating the piston displacement amplitude; an impact-detecting circuit which generates an impact signal (SI) indicating the occurrence of impact of the piston ( a control circuit that applies a variable drive signal on the linear motor, wherein: the control circuit receives the displacement signal (SD) and the impact signal (SI), and calculates, based on these signals and on the drive signal, at least an impact prevention limit parameter for the displacement signal (SD), which is proportional to the variation value or the derivative value of the displacement signal (SD) at the moment of impact, defining an anti-impact safety operating area based on this parameter, wherein the impact prevention limit parameter is calculated by the equation wherein: Slope_min is the variation value or the derivative value of the displacement signal (SD) at the moment of impact; K Period and Power are the period and power values of the drive signal at the moment of impact; and Offset_max is the impact prevention limit parameter, and wherein the control circuit compares the displacement signal (SD) generated in response to the drive signal with the impact prevention limit parameter, and adjusts the drive signal of the motor based on the result of the comparison.