Control Of Operation Modes Research Articles

An Energy-Saving Regulation Framework of Central Air Conditioning Based on Cloud–Edge–Device Architecture

As energy plays a fundamental role in our modern life and most of a building’s energy is used for air conditioning, understanding the sustainable regulation theory of central air conditioning remains a significant scientific issue. In view of three shortcomings of existing energy-saving regulation methods of central air conditioning: (1) few studies on low-latency, high-reliability, and safer energy-saving control operation modes, (2) lack of consideration for human comfort, and (3) insufficient analysis of the comprehensive impact of the human–machine–environment, this paper proposes an energy-saving control framework of central air conditioning based on cloud–edge–device architecture. The framework establishes a prediction model of human comfort based on recurrent neural network. An intelligent energy-saving control strategy is proposed to ensure indoor personnel’s thermal comfort, considering the human–machine–environment factors. This study provides a basis for better understanding the sustainable control theory of building central air conditioning. Finally, the experiment proves that the proposed method can effectively reduce the energy consumption of central air conditioning. Compared with traditional regulation approaches, the proposed real-time control strategy can save up to 91% of energy consumption, depending on the environment, and advance control strategies can save an average of 4%.

The low power diesel-generator unit with electronically controlled fuel injection

BACKGROUND: Diesel engines, used in generator units, primarily operate in variable loading conditions. Therefore, their technical and economic performance generally deteriorate when the load decreases. It arises from the diesel engine fuel system feature, where pressure and quantity of the fuel, injected into a cylinder, reduces with the load decreasing. As a result, the injection becomes sluggish, the quality of mixing process and combustion becomes worse.
 AIMS: Improvement of effective indicators of the diesel-generator units with electronically controlled fuel injection.
 METHODS: Adjustment of operation modes of the diesel engine of the electrical power unit carried out with use of electronically controlled Denso solenoid, connected to the high-pressure fuel pump via an adapter.
 RESULTS: Results of the motor testing of the low power diesel-generator unit with electronically controlled fuel feed system are described in the article. The oscillograph charts of valve displacement and solenoid magnet winding current, presented in the article, confirm its operation efficiency. Sharp decrease in boost current at the stage of valve lift can be explained by onset of back EMF. Stable solenoid operation at diesel operation velocity of 30003100 min-1 is achieved by means of boost impulse supply to its winding. The boost impulse is supplied from a voltage upconverter and generated by discharge of preliminary charged booster capacitor.
 CONCLUSIONS: Separated fuel feed adjustment in each high-pressure pump section made possible to reduce intersectional fuel feed irregularity to zero. Significant fuel consumption reduction was revealed with the motor testing of the low power diesel-generator unit with electronically controlled fuel feed system (the reduction reaches 10% on low loading operation modes). As mentioned by authors, transition to electronic control of operation modes of diesel engines of autonomous electrical power units does not require major engine design change only to dismantle a mechanical controller and to set an adapter with electronically controlled bypass valve at a section of the high-pressure fuel pump. Electronic control unit supplies current to the valve. For autonomous electrical power units, transition to this control method can be done in typical repair workshop conditions, and an update of one unit (e.g. the KIPOR KDE19AE3) costs 13 950 rubles. By doing so, one electrical power unit may save up to 1191 liters of fuel and more than 63.96 thousands rubles at a cost of 53.7 rubles per liter.

Determination of the optimal parameters of the control sensor at the crossing in the control mode

On railway sections where there are intersections with road transport, control systems for crossing signaling with auto barriers are arranged. To control the entrance of the train to this section, track circuits with insulating joints are used. Such circuits have a number of significant drawbacks, one of which is the coming off of insulating joints, as well as breakage of the track circuit, which give 45% of the failures of automation systems on the haul. In this article, a study was made of a crossing track circuit with a tone frequency for the control mode. For the study, mathematical expressions for determining the most unfavorable moment were derived, an algorithmic expression for the control mode coefficient was presented, which gives more accurate information about the presence of damage. As a result, a block diagram was developed and graphs were displayed on the simulation model showing the influence and determination of the control mode of operation of the jointless tone track circuit. In conclusion, the results of the study are summarized.

Research of the influence of the flow rate and phase composition of gas-water-oil emulsion on the errors of quantity of oil well production measurements

The article describes actual task of determining productivity index of oil and gas fields ‒ flow rate of oil and gas. Important indicator of work of an oil reservoir is average daily flow rate, which establishes technological regulation to carry out oil well products sampling. Qualitative measurement of daily flow rate will optimize and predict preventive work. Objective of the work is to study influence of flow rate, composition of the gasoil emulsion on the error in measuring the amount of oil well production. Measurements of the gas-water-oil emulsion flow rate make it possible to control development and operation modes of the field and minimize the possibility of deviations in the operation of equipment for oil and gas production. Keywords: oil reservoir; well; flow rate; error; emulsion.

Study on Quantitative Evaluation Index of Power System Frequency Response Capability

Frequency stability is an important factor for the safety and stability of the power system operation. In a traditional power system, the operation stability is ensured by the inertia response, primary frequency modulation, and secondary frequency modulation. In recent years, in order to achieve the goal of carbon neutralization and carbon peaking, China has made great efforts in new energy development. With large-scale new energy connected to the power grid, the proportion of traditional conventional synchronous units has gradually declined. At the same time, a large number of power electronic devices have been used in the power grid, which led to the capability decline of the inertia response and primary frequency modulation. For example, the East China Power Grid has experienced a sharp frequency drop in such an environment. In order to solve the above problems, the operation principle and control mode of various new energy resources are analyzed in this paper. Moreover, the process and principle of power grid frequency response are studied and the evaluation index of frequency response capability is proposed. The research results can quantitatively evaluate the system inertia response and primary frequency modulation level and provides a judgment tool for dispatching operators and system planners.

Active Power Distribution Networks with Decentralized Multi-Agent Control Mode. Part 1

The article focuses on decentralization and multi-agent automatic control as applied to the key system tasks of managing the general mode of an electric grid with distributed generation. The list of these tasks includes maintaining active and reactive power balances in normal modes, emergency control, maintaining the power supply system operability in post-emergency modes, etc. The methods for decentralized solution of these tasks, which have been tested on power system physical models and in a pilot MiniGrid project, are proposed. The developed MiniGrid is integrated with an external electrical network using a control system that is an agent of a multi-agent system. A conclusion about the possibility of developing a technology for decentralized control of operation modes in electric networks with distributed small generation is drawn. In the first part of the article, the terminology used is given, and the concept of the subject of a system for multi-agent control of operation modes in electric networks with distributed generation is given. Matters concerned with multi-agent decentralized frequency and voltage closed-loop control in an electric network with distributed generation are considered.

Integration of RES-based Power Plants into the Unified Energy System of Russia: Problematic Issues and Approaches to Solving Them

Recent years have seen mass-scale integration of wind (WPP) and solar (SPP) power plants for capacities ranging from a few to several hundred megawatts into the Unified Energy System (UES) of Russia. Wind and solar power plants for a total capacity of 5.28 GW are to be commissioned by the end of 2024, and around 6.7 GW else are to be commissioned within the next decade. WPPs and SPPs are constructed in the framework of capacity supply agreements, which guarantee the return of investments in the wholesale electricity and capacity market. The aim of the study is to analyze problematic matters concerned with integrating RES into the UES of Russia and to outline a list of first-priority and further steps to be taken for securing the optimal control of power system operation modes under the conditions of a growing share of RES in the mix of generating capacities. In view of the fact that certain power districts operating within the UES of Russia have been islanded for various reasons, the problematic matters of RES integration are analyzed also for these power system operation conditions. Experience gained around the world with integrating RES into power systems is considered, and the RES introduction scales for which certain organizational and technical measures must be developed and taken are ranked. Statistical data from Russian and foreign sources on the reliability indicators of wind farms and photovoltaic systems for various capacities are given. The equipment of modern WPPs and SPPs features high availability indicators; however, it is quite frequently disconnected, which leads to load surges on the adjacent grids and the need to cover the emergency active power shortage by conventional power plants. The article suggests a list of first-priority steps to be taken for correctly integrating RES into distribution grids that will make it possible to avoid grid equipment failures and incidents involving mass-scale loss of power supply to consumers in the course of power system operation. The implementation of the plans that have been set forth will facilitate smooth integration of the growing RES capacities into the UES of Russia, while keeping the ability to control the power systems operation modes. The article substantiates the need of introducing certain amendments to the legislation, statutory, regulatory and technical documents that set out technical requirements for RES equipment, its technological connection to and operation as part of power systems. If implemented in a goal-seeking and stage-by-stage manner, the suggested measures will help rule out excessive disconnections of RES, engage them in control of power system operation modes, guarantee reliable power supply to consumers, and secure safe and reliable performance of the UES of Russia.

A Critical Analysis of Modeling Aspects of D-STATCOMs for Optimal Reactive Power Compensation in Power Distribution Networks

Distribution static compensators (D-STATCOMs) can enhance the technical performance of the power distribution network by providing rapid and continuous reactive power support to the connected bus. Accurate modeling and efficient utilization of D-STATCOMs can maximize their utility. In this regard, this article offers a novel current-injection-based D-STATCOM model under the power control mode of operation for the reactive power compensation of the power distribution network. The versatility of the proposed D-STATCOM model is demonstrated by combining it with two of the most established distribution load flow techniques, viz., the forward–backward sweep load flow and the BIBC–BCBV-matrix-based direct load flow. Further, the allocation of the proposed D-STATCOM model is carried out under a multiobjective mathematical formulation consisting of various technical and economic indices such as the active power loss reduction index, voltage variation minimization index, voltage stability improvement index and annual expenditure index. A novel parameter-free metaheuristic algorithm, namely a student-psychology-based optimization algorithm, is proposed to determine the optimal assignment of the different number of D-STATCOM units under the multiobjective framework. The proposed allocation scheme is implemented on a standard 33-bus test system and on a practical 51-bus rural distribution feeder. The obtained results demonstrate that the proposed D-STATCOM model can be efficiently integrated into the distribution load flow algorithms. The student-psychology-based optimization algorithm is found to be robust and efficient in solving the optimal allocation of D-STATCOMs as it yields minimum power loss compared to other established approaches for 33-bus PDNs. Further, the economic analysis carried out in this work can guide network operators in deciding on the number of D-STATCOMs to be augmented depending on the investment costs and the resulting savings.

Hierarchical Pointing on Distant Displays with Smart Devices

Large display interaction has undergone considerable growth, whereas distant pointing poses challenges due to distance limitations and input devices. Smart devices with superior computing power and rich input capabilities aim to surmount these restrictions. However, pointing interactions in single-layer have limited accuracy in large display scenarios. We investigate a hierarchical pointing approach that couples multiple control modes of rotation attitude, touch operation, and pressure simulation with different cursor strategies. Specifically, it covers the dual-layer cursor with the hierarchical structure, the pressure-dependent multistage gain cursor, and the cursor projection technique based on the target acquisition mechanism. We contrast seven distant pointing techniques in two groups of experiments. Our results indicate that the hierarchical interaction strategy improves user performance, and cursor projection achieves an optimal trade-off between velocity and accuracy for high Fitts’ index of difficulty (ID) contexts.

Energy Management of Parallel Hybrid Electric Vehicle Based on Fuzzy Logic Control Strategies

Currently, the parallel hybrid electric vehicle (PHEV) is the most common type of architecture on the hybrid vehicle market. Therefore, a PHEV can be a solution to reduce emission and fuel consumption. The main challenge in the development of HEVs is the power management between the components that ensure vehicle movement. Energy management is now highly necessary by applying a control strategy (CS) in the vehicle’s traction chain, which directly affects the PHEV emission and fuel economy. The CSs have different performances, namely the control of the different power sources operation mode and the control of the battery state of charge. For this purpose, we propose a fuzzy logic CS to optimize emissions (FLCS-em) for PHEV. To assess this approach, we compare it with the most commonly used and recent EMS, in particular the strategy to optimize fuel use (FLCS-f), the efficiency optimization strategy (FLCS-eff) and the electric assist CS (EACS), in urban and highway driving cycles. The results show that the elaborate FLCS-em, characterized by a limited number of rulers, provide significant advantage than CSs mentioned in terms of the efficiency of PHEV performance and emissions and fuel consumption minimization.

State Evaluation and Fault Prediction of Protection System Equipment Based on Digital Twin Technology

Digital twin technology aims to build a map of physical entities in virtual space, and simulate the real-time state and dynamic characteristics of physical devices through bi-directional interactive data flow. In order to guarantee the safe and stable operation of protection system equipment in intelligent substations and improve the efficiency of protection system operation and condition maintenance, this paper proposes a protection system state evaluation and fault prediction method based on digital twin technology. The architecture, application and operation control mode of digital twin technology in a real-time state analysis of a protection system are studied. The state evaluation model based on matter-element extension and the fault prediction model based on clustering algorithm are constructed. By analyzing the historical data of an intelligent station protection system in actual operation, a database that can be updated and corrected in real time is constructed. The effectiveness and accuracy of the state evaluation and fault prediction method are verified with actual cases, which can provide technical support for the operation and maintenance of the protection system.

Methods of controlling operation modes in Pt/TaO x /Ta2O5/Pt resistive switching cells

Forming and resistive switching (RS) characteristics of Pt/TaO x /Ta2O5/Pt cells were investigated when the TaO x thickness was varied. With an increase in the TaO x thickness, a semi-forming process, which is defined as a transition from an initial state to high resistance states more than 1 kΩ, occurs more frequently. The semi-forming can be understood as the formation of an incomplete filament with a gap or a constricted part in the Ta2O5 layer. Moreover, in a single cell after the semi-forming, selective control of RS operation modes was achieved by simply adjusting the range of the applied voltage. In a complementary RS mode where both set and subsequent reset processes occur at both positive and negative voltages, analog RS characteristics can be observed. The control of the RS operation modes could be useful for the improvement of the multi-leveled controllability of resistance.

Grid-Forming Operation of Energy-Router Based on Model Predictive Control with Improved Dynamic Performance

The focus of this study is on the grid-forming operation of the Energy Router (ER) based on Model Predictive Control (MPC). ER is regarded as a key component of microgrids. It is a converter that interfaces the microgrid (s) with the utility grid. The ER has a multiport structure and bidirectional energy flow control. The ER concept can be implemented in Nearly Zero-Energy Buildings (NZEB) to provide flexible energy control. A concept is proposed where the ER works as a single grid-forming converter. The challenge is to keep the predefined reference voltage and frequency inside the NZEB in all possible modes, including the idle operation mode, current sources, and nonlinear load control. To gain stability and output voltage quality, the MPC is proposed. The design of the modified MPC algorithm with improved dynamics performance is explained. PLECS software is utilized to verify the proposed algorithm. The results demonstrate the suitable performance of the proposed control method in terms of total harmonic distortion of the output voltage. The influence of weighting coefficiencies is evaluated, showing the higher impact of the capacitor filter voltage on lowering the total harmonics distortion of the output voltage. Finally, the capability of the control system toward step change in the reference value is evaluated.

Research on cluster operation optimization of multi‐port energy routers

The penetration rate of distributed new energy and DC load increase in the distribution network improve the new energy consumption rate and the reliability of power supply. This paper proposes an AC/DC hybrid system structure with multi-port energy router (ER) cluster, and compares the advantages of this structure over the AC/DC hybrid microgrid with multiple conversion links. In order to realize the stable, economic, and reliable operation of this structure, the multi-layer and multi-time scale control method and communication mode are established. According to the non-linear characteristics of energy consumption of ER port, the optimization model of the cluster control layer and the control mode of each port in the cluster system are studied. By setting several examples, the rationality of the proposed ER cluster operation control mode and the optimization method and the effectiveness in improving the total energy efficiency of the ER cluster system are verified; the advantages of ER cluster operation in improving the operation energy efficiency of key devices in the distribution network are illustrated.

Recent Advances on Distributed Dispatching and Control Algorithms in Virtual Power Plant

In recent years, the concept of Virtual Power Plant (VPP) is becoming more and more popular due to its capability of aggregating Distributed Energy Resources (DERs) and exploring its potential of providing flexibility to the existing power grid. Distributed algorithms have several potential advantages over centralized approaches, such as sharing limited amounts of information, performing parallel computations, and having strong robustness. In this context, this paper surveys the literature of distributed algorithms regarding VPP applications. Firstly, we established the VPP framework and operation control modes. Secondly, the basic distributed algorithms were given. Then, this paper studied distributed algorithms in VPP for economic dispatch, bidding optimization, autonomous control strategy within VPP, coordinated control strategy among muti-VPP, and interactive control strategy with grid side. Finally, the key issues and research potential were analyzed.

Architecture design of battery energy storage coordinated control system based on Multi-Agent mechanism

Abstract Energy storage can realize rapid voltage, frequency support and energy adjustment, and is an important guarantee for promoting the efficient consumption of renewable energy and the safe and stable operation of the power system. The flexible adjustment of energy storage is not only affected by its own characteristics, but also closely related to the operation control mode of energy storage. Based on the PQ constant power and virtual synchronization control strategy of the battery energy storage system, this paper constructs the operation architecture of the battery energy storage system based on the Multi-Agent cooperative mechanism, and further gives the energy storage system Multi-Agent cooperative control system’s application scenarios in active frequency modulation and reactive voltage regulation. Research shows that this architecture helps to fully tap the potential of aggregation and regulation of multi-point decentralized energy storage facilities and meet the flexible regulation needs of the power system under the access of high-permeability intermittent renewable energy.

Multi-stage supply restoration of active distribution networks with SOP integration

Supply restoration from outages is essential for improving the reliability of active distribution networks (ADNs) after fault isolation. Soft open point (SOP) can adjust the power flow among feeders and provide voltage support for power outage areas. Considering the sequential coordination of switching operation and SOP control mode selection, a multi-stage supply restoration method with SOPs is proposed for ADNs. First, the sequential energization is formulated, in which the impact of SOP control mode on restoration sequence is analyzed. By providing voltage support, the coordination of SOPs will rapidly energize the outage area and improve the voltage profile. Then, a multi-stage restoration model with SOPs is proposed, in which reconfiguration of switches and control mode selection of SOPs are coordinated in sequence to maximize the load recovery level of ADNs. Through the switching action-time mapping, secure operation is ensured during the entire supply restoration process. Finally, the effectiveness of the proposed method is validated on a modified IEEE 33-node distribution system and practical distribution networks with four-terminal SOP. Results show that the proposed method can fully exploit the potential benefits of SOPs and effectively enhance the load recovery level of ADNs.

Computer Simulation Research of Self-adaptive Compensation Control Based on Neural Network for Control Surface Failure of Uncertain Tailless Flying Wing Aircraft

The conventional aircraft layout will contain the elevator, aileron, rudder three control surfaces, and thus generate three control moments to adjust the aircraft trajectory and flight attitude. However, the aircraft with multi-control plane flying wing layout needs to choose redundant new control plane configuration, which is quite different from the conventional aircraft layout in both control method and operation mode. Since there are many problems in the aircraft motion mathematical model during the ownership period, which will directly affect the control effect of the flight control system, in order to reduce dynamic error and improve the robustness and accuracy of the flight control system, this paper proposes an adaptive neural network algorithm. Combined with the current operating status of tailless flying wing aircraft and the research status of aircraft control system analysis, this paper mainly discusses the design differences between the adaptive control system and the original control system, based on the empirical case, to clarify the compensation effect of the adaptive control system.

Neural Network Model for Control of Operating Modes of Crushing and Grinding Complex

This article investigates the application of neural network models to create automated control systems for industrial processes. We reviewed and analysed works on dispatch control and evaluation of equipment operating modes, and the use of artificial neural networks to solve problems of this type. It is shown that the main requirements for identification models are the accuracy of estimation and ease of algorithm implementation. It is shown that artificial neural networks meet the requirements for accuracy of classification problems, ease of execution and speed. We considered the structures of neural networks that can be used to recognize the modes of operation of technological equipment. Application of the model and structure of networks with radial basis functions and multilayer perceptrons for the tasks of identifying the mode of operation of equipment under given conditions is substantiated. The input conditions for the construction of neural network models of two types with a given three-layer structure are offered. The results of training neural models on the model of a multilayer perceptron and a network with radial basis functions are presented. The estimation and comparative analysis of models depending on model parameters is made. It is shown that networks with radial basis functions offer greater accuracy in solving identification problems. The structural scheme of the automated process control system with mode identification on the basis of artificial neural networks is offered.

Modeling and control of an invasive mechanical ventilation system using the active disturbances rejection control structure

We propose a mandatory invasive mechanical ventilator prototype for severe COVID-19 patients with volume and pressure control operation modes. This system comprises basic pneumatic elements and sensors. Its performance is similar to commercial equipment, and it presents robustness to external disturbances and parametric uncertainties. To develop a control strategy, we propose a mathematical model with a variable structure that incorporates the dead zone phenomenon of the proportional valve, and considers external disturbances and parametric uncertainties. Based on this model, we propose a global control strategy that is based on pressure and flow regulation controllers, which use the active disturbances rejection control structure (ADRC). In this strategy, we propose robust state observers to estimate disturbances and the signals necessary for implementing the controllers. We illustrate the performance of the prototype and the control strategy through numerical simulations and experiments. We also compare its performance with PID controllers. These results corroborate its effectiveness and the possibility of its application in invasive mechanical ventilators with a simple structure, which can significantly help critical care of COVID-19 inpatients.