摘要 |
A PID control for a vapor compression system utilized to heat water identifies a particular range of error signals and derivative of the error signals that could be indicative of the cycle moving in an inefficient direction. If this determination is made, then a substitute for the error signal is utilized. In particular, the determination is made if both the error and the derivative of the error are negative. The substitute multiplies the error with its derivative to result in a positive product. This ensures the system will not move in the inefficient direction.
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