Parameters and characteristics analyses in choosing high-speed automatic transfer switch (HSATS) devices for oil and gas plants power systems
High-speed automatic transfer switch (HSATS) has been designed to enhance security of Essential Service supply and to provide dynamic stability of complex electromotor load in cases of short-run disturbance of power supply input. Its performance is based on continuous monitoring of line-to-earth voltage and current values at busbars of two distributor gear incoming units, their transformation into complex effective voltage and positive-sequence current values as well as software processing of measurement values . The device appears to be only one component of HSATS system which apart from the start-up system itself comprises also current and voltage transformers as well as power cutoff switches, their number depending on distributor gear circuit. While among these only power cutoff switches can influence transfer speed. This fact determines the necessity to use modern ballistic breakers that provide standby uninterrupted power supply system (UPS) total switching time taking into consideration starter action time thus providing full load performance independent of its composition. The article covers the results of the differential analyses of parameters and characteristics of HSATS most frequently used at oil and gas plants. The main problems arising in the process of such devices operation are studied.
The article considers the problems of regulation modes of pumping oil through main pipelines switching the number of the pumps. Explain the rationale for the use of variable frequency drives to regulate the performance of the pipeline. Specified technological section of the pipeline recorded balance equation pressures for frequency regulation main pumps, taking into account regulated pumps. In the article speed of the main pumps with the modes and speeds of other pumps of technological area are discussed. The generalized expressions for the speed pumps that are valid for any number of variable pumps at pumping stations are investigated. The algorithm of calculation speeds of main pumps, when all of them have the same speed of rotation is given. The block diagram of the algorithm is shown.
This article deals with features of conductometers used in drilling and well testing. It shows the advantages of a non-contact conductivometer with liquid-loop connection. This work identifies weaknesses of such devices associated with the impact of influencing factors such as harmonic oscillations source stability, signal frequency stability, ambient temperature, which all affect the accuracy of measurements. The article proposes a scheme of a non-contact conductometer with compensating coil connected to a conductance box. The operation of such a device has been carried out. As a result, no effect of influencing factors in such a conductometer was found. An experimental model of the device was designed for verification of theoretical conclusions. The scheme of such a model has been shown. Experiments demonstrating the efficiency of the proposed model have been carried out. The deviation of the influencing factors from the nominal values at ±10% did not affect the result of the measurement, which corresponds to the theoretical calculations. This article also considers two types of magnetic fluxes compensation in the analyzed model of a conductometer: phase and amplitude compensation methods. It was revealed that the phase compensation method allows for more accurate results, due to the low sensitivity requirements for measurers when determining a phase shift. The authors of this article encourage developing conductometer based on the proposed model.
The study of errors of resistance transformation of resistive sensors, while providing the quasi-invariance to the resistance of the cable insulation of the communication channel
In the present article the studies of errors of resistance transfomation of resistive sensors ensuring the quasi-invariance to the resistance of cable insulation of the low conductivity measurement systems (MS) are considered. Open structure of the resistance transducer of resistive sensors (CRRS) provides the invariance to change of parameters of the communication channel (CC). This ensures conducting of the operation in hardest conditions, such as the measurement at the depth under conditions of high stationary temperatures.