Patent UA-87460-U (UA)
Title: Method for identification of parameters of electro-hydraulic complex
IPC: G01R11/50
Filed: 2013-08-05
Abstract: A method for identification of the parameters of electro-hydraulic complex includes determination of the parameters of electro-hydraulic complex at its operation. To the input of the control system of the frequency transformer effect of test harmonic is applied,, this includes the constant Uand alternating Ucomponents where Ω=2πf – angular frequency; f – frequency of change of the input signal; φ – angle of shift of the signal of setting with respect to the origin; by means of the velocity sensor discrete measurement of current frequency of rotation n(t) of the drive motor of the pump is carried out, with determination of the relative frequency of rotation v(t) = n(t)/nof the pump unit, where n– rated value of the frequency of rotation of the electric motor of the pump. Signal of capacity Q(t)=Qv(t) at the output of the pump unit is calculated, where Q– rated value of capacity of the pump unit; depending on the chosen equivalent circuit of electro-hydraulic complex number of unknown parameters is determined. Signals of instantaneous power on each element of the equivalent circuit of the electro-hydraulic circuit are calculated: at the outlet of the hydraulic source (pump) p(t)=Hv(t)Q(t), where H– head formed with the pump at zero productivity; hydraulic power p(t)=HQ(t) in pipeline network consumed to overcome the counter-pressure H; hydraulic power p(t)=RQ(t) on the active resistance of the pump R=αQ(t), where α - coefficient of approximation that takes into account the forces of viscous friction between the layers of liquid, liquid and the walls of the hydraulic section of the pump. Hydraulic power p(t)=RQ(t) on the active resistance of the pipeline R=δ/Q(t), where δ – coefficient of approximation that takes into account the length of the section of the continuous flow section of the pipeline, its diameter, kinematical viscosity and density. Hydraulic power p(t) = RQ(t) on the active resistance of consumer R. Hydraulic poweron the reactive resistance of the pipeline, where γ – coefficient of approximation that takes into account the properties of liquid and geometric parameters of the pipeline; power signals obtained are represented by trigonometric series with use of Fourier transformations, with determination of constants (P, P, P, P, P, P) and variable cosine (P, P, P, P, P, P) and sine (P, P, P, P, P, P) harmonic components of signals of instantaneous hydraulic power at the output of the source of hydraulic power supply and all the elements of equivalent circuit of the electro-hydraulic complex, where k – number of respective harmonics of power; system of identification equations is compiled on basis of the equation of energy balance of the constant and harmonic components of instantaneous power at the output of the hydraulic source and all the elements of equivalent circuit. Needed number of valuable harmonics of power is chosen, this corresponds to the number of unknown parameters of the equivalent circuit; the system of identification equations is solved, with determination of unknown hydraulic H, α, δ, γ, Rand energy parameters of the electro-hydraulic complex: active power at the output of the hydraulic source (pump) Pand on the elements of the equivalent circuit EGK P, P, P, P, respectively; power losses in the pumpand in the pipelinetotal power losses in the electro-hydraulic complexefficiency of the pump unit