Research of current distribution by phases in asynchronous electric motor with a combined winding

THE PURPOSE. To consider the features of power supply system of oil and gas production complex, variety of layout of electrical complexes of producing wells. To develop a universal methodology for determining optimal voltage value in power supply center, that is, on substation power bus.METHODS. When calculating voltage in power supply center, which provides a certain amount of voltage on stator of most remote electric motor, method of equalizing potentials in nodes of outgoing line was used when calculating loads of elements of electrical complexes of producing wells. The development of a methodology for calculating optimal voltage of power supply center was carried out using the method of cognition, which was called ascent from simple to complex. The search for optimal voltage value of power supply center must be carried out by numerical methods with involvement of a software product that allows use of search algorithms.RESULTS. The article proposes a method for calculating optimal voltage of power supply center of outgoing line of an oil and gas producing enterprise. The developed technique can be applied under a wide range of energy optimization criteria and for any configuration of outgoing line circuit, takes into account technological features of the process of mechanized oil production and ensures a reduction in electricity consumption.CONCLUSION. The calculation method considered in article makes it possible to develop an optimal list of organizational and technical measures for voltage regulation in distribution network in order to reduce power consumption.

Power Bus Management Techniques for Space Missions in Low Earth Orbit

In space vehicles, the typical configurations for the Solar Array Power Regulators in charge of managing power transfer from the solar array to the power bus are quite different from the corresponding devices in use for terrestrial applications. A thorough analysis is reported for the most popular approaches, namely Sequential Switching Shunt Regulation and parallel-input Pulse Width Modulated converters with Maximum Power Point Tracking. Their performance is compared with reference to a typical mission in low Earth orbit, highlighting the respective strengths and weaknesses. A novel solar array managing technique, the Sequential Maximum Power Tracking, is also introduced in the trade-off and was demonstrated able to boost energy harvesting, especially in the presence of mismatching in the solar array. It also can achieve top levels of reliability using a rather simple control hardware. Its operation was verified both by a Matlab–Simulink model and by an experimental breadboard.

Identification of the Technical Condition of Induction Motor Groups by the Total Energy Flow

The paper discusses the method of identifying the technical condition of induction motors by classifying the energy data coming from the main common power bus. The work shows the simulation results of induction motor operation. The correlation between occurring defects and current diagrams is presented. The developed simulation model is demonstrated. The general algorithm for conducting experiments is described. Five different experiments to develop an algorithm for the classification are conducted: determination of the motors number in operation with different power; determination of the motors number in operation with equal power; determination of the mode and load of induction electric motor; determination of the fault and its magnitude with regard to operation and load of induction motor; determination of the fault and its magnitude with regard to operation and load of induction motor with regard to non-linear load in the flow. The article also presents an algorithm for preprocessing data to solve the classification problem. In addition, the classification results are shown and recommendations for testing and using the classification algorithm on a real object are made.

Message Queuing Telemetry Transport Communication Infrastructure for Grid-Connected AC Microgrids Management

In a context with an increasing number of non-traditional power sources, smart inverters function as the main interfaces between distributed energy resources (DERs) and the power bus. This role is even more prominent in microgrids (MGs), where numerous DERs must be controlled and coordinated. For this aim, MGs need to implement suitable communication links since, even in distributed control, the system must compensate voltage and frequency deviations caused by local controllers. Likewise, a communication system is required to optimize its operation. This paper aims to apply the technological advances brought by the Internet of Things (IoT) to the issue of communication within an MG. The work proposes a wireless communication architecture based on the message queuing telemetry transport (MQTT) protocol, accompanied by a set of requirements and specifications to establish a multi-directional information flow between DERs in an MG, and potential energy management system (EMS) or secondary controllers. A laboratory-scale testbed was implemented to demonstrate the operation of an EMS in the proposed architecture. The experimental results showed how current control structures seamlessly integrate with the proposed communication system. Furthermore, it was demonstrated that communication latencies or failures did not comprise the stability of the MG, but only decreased the optimality of the EMS control strategy.

Cascade Configuration of Modal Filters for Power Bus Protection in Differential and Common Modes

The paper discusses the results of quasi-static simulation of two modal filter (MF) cascade configurations designed to attenuate an interference pulse in differential and common modes. The geometric parameters of the MF are optimized by heuristic search according to the amplitude minimization condition. The results of calculating the time responses to an ultrashort pulse (USP) and electrostatic discharge (ESD) are presented. The USP attenuation coefficient in the differential mode was 6.84 times for the horizontally placed cascades, and 6.94 times for the vertical configuration. In the common mode, the attenuation coefficient was 7.35 times for the horizontally placed cascades, and 7.57 times for the vertically placed cascades. For ESD, the attenuation coefficients were 1.51 times for the horizontally and 1.55 times for the vertically placed cascades in the differential and common modes. It was found that only the first spike is attenuated by the ESD excitation on the MF

The Analysis of Shielding Effectiveness of the enclosure of an EMI-Filter for a Spacecraft Power Bus

In this paper, the shielding enclosure of an electromagnetic interference (EMI-) filter for a spacecraft power bus was analysed for shielding effectiveness (SE). By using an electro- dynamic approach, the authors conducted simulation in the frequency domain taking into account losses in the shield. The investigation covered the performance of the shielding enclosure with and without the connected cables and the in uence of apertures formed between the enclosurebase and its cover. It was found that the smallest value of the SE of the enclosure is observed for the configuration with unshielded cables. However, whilst maintaining shielding integrity, attenuation of at least 88 dB in the frequency range from 0 to 20 GHz was achieved. In the study, the authors analysed the in uence of printed circuit boards of EMI-filter in the shielded volume on SE of the enclosure and found that they have a weak effect on the SE. In conclusion, there is some practical guidance on the design of similar EMI-protection devices.

Fault-Tolerant Battery Power Network Architecture of Networked Swappable Battery Packs in Parallel

To improve the reliability and energy efficiency of battery swapping, we constructed a battery power network system with active redundancies and with multiple battery management controllers (one in each newly developed smart redundant battery pack). Each pack is getting ready to assume the role of the major to coordinate direct safe mounting of the packs onto the power bus for load sharing or charging without the need for a direct current to direct current converter. This fault-tolerant architecture provides multiple backups in both management control and power supply. To verify this design, the mounting, insertion, and removal of the battery packs were executed during charging and discharging. Battery packs can be swapped on and off safely at any time regardless of their charging states. Battery packs can be direct safe mounted onto the power bus by a threshold algorithm. With each mount on event, the equivalent output energy conversion efficiency ranges from 98.3% to 99.2% throughout the transient. Moreover, when the major battery pack fails or gets removed, other battery packs can indeed assume the role of major safely. The reliability, energy efficiency, and safety of our system were verified.