Modeling of Hydraulic Load of Electric Drive in Electrical Complex of Pumping Station

Abstract

Sudden pipe bursts occur in high-pressure water transmission pipelines and water distribution networks. The consequences of these bursts can be very expensive due to the outage time while the burst pipe is repaired, the cost of repair, and damage to surrounding property and infrastructure. As a result, it is advantageous to minimise the detection and location time after the burst occurs.Currently, there is no effective solution for the burst detection and location problem in water distribution systems. The applications in oil and gas pipelines and pipe networks show the advantages of continuous monitoring. A number of techniques are used to determine the location and size of a burst. One of the most promising approaches is fluid transient modelling and analysis. Pressure transient analysis has also been successfully applied for detection and location of existing leaks.A sudden pipe burst creates a negative pressure wave that travels in both directions away from the burst point. The analysis of this wave is the main principle for the techniques presented in this thesis. Experiences from previous research suggest that, to achieve the best performance, single pipelines and pipe networks have to be treated separately. Thus, two different approaches for burst detection and location are presented.When a burst occurs in a pipeline, the burst-induced pressure wave travels in both directions along the pipeline and is reflected at the boundaries. Using a pressure trace measured at one location along the pipeline, the timing of the initial and reflected burst-induced waves determines the location of the burst. The presented continuous monitoring technique uses the modified two-sided cumulative sum (CUSUM) algorithm to detect abrupt changes in the pressure iii data caused by the pipe break. The results from both laboratory and field pipelines are used to verify the proposed method. Different burst and measurement locations are tested. The results are promising for burst detection and location in real systems.In the network case, continuous pressure measurements at two locations are analysed. The burst detection and location algorithm is based on the difference between the arrival times of the burst-induced pressure wave at each measurement point and on the measured wave magnitude. The arrival times are determined automatically in real time. A method for determining optimal measurement locations is also presented. Results from numerical simulations show that the proposed technique has potential as a tool for effective detection and location of bursts in real pipe networks.

Dynamic Modelling of Centrifugal Hydraulic Load of Pumping Station Electric Drive

“…A series of mathematical experiments, the results of one of which are presented in Figures 2-7, and comparison of their outcomes with the operational characteristics of the corresponding CP confirm the validity of the proposed mathematical model. For the nominal rotational speed of the impeller, the discrepancy between the head and flow characteristics and energy conversion efficiencies obtained on this model and the model of the steady state modes [9] does not exceed 15% in the flow rate range of 13.3%..249% of the nominal value.…”

“…The analysis of the modes of this complex was set as an objective and was partially solved in [6], whereas the control systems of the complex were developed in [7], [8]. A more detailed consideration of the main internal hydraulic parameters of EDCP and the pipeline was implemented in the mathematical model [9] of the hydraulic load of the PS electric drive. In these studies, the representation of each subsystem of the PS electric complex provide sufficient detail, but they deal with steady state modes only.…”

Dynamic Modes of Synchronous Electric Drive with Centrifugal Hydraulic Load of Pump Station

“…The mathematical model of CP with a pipeline presented in [16] based on [14], [15] was taken as the base according to the principle of electrohydraulic analogy, considering the following assumptions: the temperature mode is steady-state, and the hydraulic fluid is uncompressible and homogeneous. This model makes it possible to study the dynamic modes both of CP as a whole and of its internal elements, taking into consideration the influence of the pumping modes and physical properties of the fluid.…”