Providing noise immunity in air supply control systems with compressor units

The problem of noise droop in the measured signal at the input of the circuit, which includes a PID controller, a frequency converter, an asynchronous motor and a compressor for supplying air to the apparatus, is considered. It is proposed for noise droop to introduce a nonlinear dead zone (NZ) at the controller input, which is determined by the requirements of the control accuracy in a stationary mode and is implemented using an approximating nonlinear function with saturation. As a result, noise droop is achieved at the NZ output by error asymptotic approximation to zero, in contrast to the threshold noise suppression. Research is carried out and results that reflect the effectiveness of the proposed solution is obtained. Keywords approximating nonlinear function, dead zone, PID controller, noise droop coefficient, transient process