ASSESSMENT OF CONSUMERS POWER CONSUMPTION OPTIMIZATION BASED ON DEMAND SIDE MANAGEMENT

To solve the problems of high functional requirement, complex structure and poor versatility of manned spacecraft power supply and distribution ground test equipment, a modular universal ground power supply system (PSS) is designed. The functions of the system cover the functions of wire instruction opening, parameter measurement and state detection of the interface between the manned spacecraft and the ground equipment, and realize the universal and extensible configuration. This paper provides a general architecture design method for complex manned spacecraft power supply and distribution ground test system.

The synthesis problem of energy supply systems includes the selection of proper heating and power generating units as well as energy integration. Such problems have been generally formulated as a linear programming (LP) problem. The structural analysis of the problem and solutions is focussed on rather than merely solved. As a practical consideration for preliminary selection of technologies, a problem regarding the selection of heating devices such as electric heaters, furnaces, steam heaters, or heaters with a heating medium under given loads is defined as a synthesis problem of optimal heat and power supply systems and formulated into an LP form with an objective function of minimum fuel. The results of analysis of the LP problem clarify essential structures of heat and power supply systems under arbitrary heat and power demands.

An individual power supply source is usually used for each group of identical magnetic elements in accelerators of charge particles. We discuss the power supply and control system on the basis of additional current shunts applied for the simultaneous supply of several groups of magnets in the positron storage ring of the Low-Energy Particle Toroidal Accumulator (LEPTA). Data on the use of the shunt of the linear and key converter are given. The option of the device of a power supply system with the transformation of the recuperated energy in the storage battery and supply from it of the precision power supply sources of the LEPTA correcting magnets is considered. A channel of the individual digital transformation of power supply system elements is given which allows one to build, together with a reverse precision converter, effective intellectual balanced power supply systems.

A set of mathematical models for calculating the reliability indexes of structurally complex multifunctional combined installations in heat and power supply systems was developed. Reliability of energy supply is considered as required condition for the creation and operation of heat and power supply systems. The optimal value of the power supply system coefficient F is based on an economic assessment of the consumers’ loss caused by the under-supply of electric power and additional system expences for the creation and operation of an emergency capacity reserve. Rationing of RI of the industrial heat supply is based on the use of concept of technological margin of safety of technological processes. The definition of rationed RI values of heat supply of communal consumers is based on the air temperature level iside the heated premises. The complex allows solving a number of practical tasks for providing reliability of heat supply for consumers. A probabilistic model is developed for calculating the reliability indexes of combined multipurpose heat and power plants in heat-and-power supply systems. The complex of models and calculation programs can be used to solve a wide range of specific tasks of optimization of schemes and parameters of combined heat and power plants and systems, as well as determining the efficiency of various redundance methods to ensure specified reliability of power supply.

Chapter 9 - Integrated Planning of Energy and Water Supply in Islands

Hose-drawn traveler (HDT) is a significant type of sprinkler irrigation equipment in China. In arid and remote areas, where grid power is unreliable or unavailable, the water pumping system of the HDT typically depends on a complementary power supply (CPS) system integrating batteries, photovoltaic (PV) panels, and gasoline generators. However, the configuration of the CPS system is often determined empirically, which can lead to increased costs and compromised operational reliability. This paper aims to optimize the configuration of the CPS system based on the power demand of the water pumping system in HDT. We propose an optimization model for component sizing that considers both the annual costs and reliability of the power supply system. An improved particle swarm optimization (PSO) algorithm, incorporating a penalty function, is employed to determine the optimal configuration of the CPS system. The proposed optimization approach is then applied to an HDT operating in three typical regions in China: Golmud, Beijing, and Harbin. Finally, a comparative analysis of the configurations and annual cost of two CPS systems, PV-battery (PVB) and PV-battery-gasoline (PVBG), is conducted. Results show that for a given region, season, and power of water pump, the PVBG system needs a smaller PV panel area and lower battery capacity than the PVB system. For a fixed region and season, increasing power of water pump leads to a more significant rise in the annual cost of the PVB system than in that of the PVBG system. At high pump power levels, the PVBG system is more cost-effective, resulting in a lower annual cost than the PVB system. In Golmud, under identical seasonal and pump power conditions, both systems have lower annual cost than in Beijing and Harbin, suggesting that Golmud is a more suitable region for deploying CPS systems. The proposed method provides a reference for designing power supply systems of HDT irrigation.

Assessing the impact of systemic heterogeneity on failure propagation across interdependent critical infrastructure systems

A train driven by a linear thyristor motor (LTM) moves by one pitch of the ground coil in every cycle of the power supply voltage. Therefore the vehicular speed is determined by the power supply frequency, and the travel distance is determined by the number of cycles of the supplied power source voltage. This means that the speed and location of the vehicle are monitored and controlled completely by the power supply system. Hence, no information channel is required at least theoretically which connects the vehicle with the ground station. This paper proposes a power supply and control system for LTM and confirms its operating performances using an outdoor loop-type model system with circumferential length of 100 m.

The program of measures to introduce modern resource-saving technologies for the most effective management of renewable resources will provide the necessary amount of energy to both the population and industrial enterprises. The energy power supply system includes energy power plants using various renewable energy sources (hydraulic, wind, solar) that create more favorable conditions for its stability modes. Unification of power plant using various renewable energy sources (hydraulic, wind, solar) in power supply system has created more favorable conditions for use of power resources. These power plants have their own features of operation modes and definite work place in the production schedule of power supply system. During power supply operation daily production schedules define an operating mode of the system as a whole, including all its elements, from generating sources to high-voltage transmission lines and distributive networks system. The results of given researches are allowed to create the methods of increasing stability, reliability and efficiency supply systems with using renewable energy sources.

Comparing with the large power system, power supply system of steel enterprise has significantly different characteristics, and there has been relatively little research on its stability control. Power supply system of steel enterprises, as a typical active power-receiving system, generally has private power plants, which connected with external power grid. When disconnected with external power grid due to certain fault, it will result in frequency collapse, and even leads to large-scale blackout owing to the active power imbalance. Through analysis of the stability of one power supply system in a large-scale steel enterprise, under frequency load shedding and regional security and stability control system are adopted in this paper. The latter is applicable in various modes of operation in complex power supply systems, but with more investment.

Relevance The article is devoted to the study of the possibility of occurrence of ferroresonant processes in power supply systems with distributed generation. Ferroresonant processes cause overvoltages in electrical installations and lead to their failure. In backbone and distribution networks without distributed generation facilities, the phenomenon of ferroresonance has been studied quite deeply, effective hardware and operational measures have been developed to prevent the occurrence of ferroresonance surges in electrical installations. However, the issue of the occurrence of ferroresonant processes in power supply systems with distributed generation, which is a promising direction in the development of the energy sector, seems to be little studied. Aim of research The main aim of the research is to investigate circuit-mode conditions for the occurrence of ferroresonant processes in power supply systems with distributed generation. Research methods To study the circuit-mode conditions for the occurrence of ferroresonant processes in power supply systems with distributed generation, the main provisions of the theory of electrical complexes and systems, the theory of nonlinear electrical circuits, and the principles of controlling objects of electrical complexes and industrial systems were used. Results The circuit-mode conditions for the occurrence of ferroresonant processes in power supply systems with distributed generation are studied. The power supply system of a HF radio center, containing a power plant with a lower installed power or corresponding to the maximum power consumption of the load, was chosen as the object of study. The features of the scheme-mode conditions for the occurrence of ferroresonant processes under conditions of distributed generation are as follows. Due to the insignificant remoteness of distributed generation facilities and consumers, additional opportunities arise for subharmonic ferroresonant processes. When a generating plant is connected to low-voltage busbars, conditions are created for the occurrence of a ferroresonant process involving low-voltage windings of power transformers. The low dynamic stability of generating installations of distributed generation facilities based on synchronous generators reduces the likelihood and duration of ferroresonant processes in the event of phase wire breaks and short circuits on the power line. Generating plants connected via grid inverters have a limited output current and can be turned off by emergency automatics in the event of an emergency operation of the grid, which, as a rule, precedes the appearance of ferroresonant overvoltages in electrical installations. Thus, in power districts with distributed generation facilities, the circuit-mode conditions for the occurrence of ferroresonant processes, known in the centralized power supply system, undergo changes, and it is also possible to form new ferroresonant oscillatory circuits. Keywords: distributed generation, ferroresonant process, power supply system, oscillatory circuit, generating plant, relay protection and automation devices Acknoledgements: The work was carried out under the state order of the Omsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences (project state registration number 122011200349-3).

Several publications have been devoted to the development of traction power supply for alternating current [1, 2]. They set the task of considering the resistance of the external power supply system and power traction transformers when calculating the current distribution in traction networks. With all the merits of the existing methods for calculating these resistances, there are discrepancies in the published sources in determining the parameters of the equivalent circuit for the traction power supply system [3, 4, 5, 6]. In the present work, the authors propose a technique for calculating reduced to a voltage of 27.5 kV equivalent resistances of an external power supply system and a power traction transformer. An equivalent circuit for replacing the traction power supply system is substantiated, allowing to take into account the voltage drop on the overall resistance of the external power supply system from the traction currents of the considered and adjacent feeder zones, as well as transit currents flowing through the power lines. Using the method of symmetrical components it was obtained that when calculating the internal resistance of a traction substation consisting of the resistances of the longitudinal power supply line and the power traction transformer, it is necessary to use the calculated formulas obtained when taking into account the actual current distribution in the secondary (traction) winding of the power traction transformer. It is shown that the traction network equivalent circuit for the calculation of short-circuit currents, given in [1, 2], does not reflect the real current distribution relationships in traction networks. The main reason for the inconsistency of the scheme proposed by a number of experts with the existing traction power supply system is determined by an unjustified transition from an asymmetric system “three-phase transmission line - transformer - power supply system - single-phase traction network” to a single-line calculation scheme. When calculating the current distribution according to this scheme, there is no metallic connection of the track with one of the phases (more often phase C ) of the power traction transformer. The absence of this connection leads to the flow of traction currents between the district and traction substations, short-circuit current on the ground, which is not permissible.

Based on the engineering application design and development of the power supply system of lithium iron phosphate battery pack in the operation and maintenance mode, this paper conducts the application research from four aspects of battery quantity selection, capacity calculation selection, battery management system design, battery pack modular design, etc. The design scheme of the lithium iron phosphate power supply system is formulated, and the matching battery management system is designed. A universal lithium iron phosphate battery module with an “N+1” redundant configuration is developed to improve the maintenance efficiency of the battery pack. It reliably supports the substation power changing operation and maintenance mode and ensures the reliability and operation safety of the substation power supply system.

Several Ideas on Fire Detecting Alarm for Power Supply and Distribution System

<div class="htmlview paragraph">A lot of electric components have been installed in a vehicle today for comfort, safety and environment. This tendency is said to be continued in the future. Therefore, additional power supplies such as exhaust gas electricity generation system and thermal electricity generation system have been developed in the world to supply additional electricity as well as an enlargement of an alternator. However, if these new electricity supply systems are installed in a present electric power system that is controlled based on a voltage feedback, each supply system cannot be controlled effectively, because it is difficult to control output power of each system independently. An electric power based control system, <u><b>V</b></u>ehicle <u><b>E</b></u>lectric power <u><b>F</b></u>low management system (<b>VEF</b>), has been developed to avoid this problem.</div> <div class="htmlview paragraph">Sum of required electric power is calculated based on electric loads power and battery charging power. This required power is allocated to each power supply system. This assignment is performed according to an index, a running cost of electricity. This index is called <b>DENPI</b> (<u><b>D</b></u>esign of <u><b>E</b></u>lectric <u><b>N</b></u>etwork with <u><b>P</b></u>ower <u><b>I</b></u>ndex). For example, <b>DENPI</b> of the alternator changes according to an engine torque, a rotational speed and efficiency. Therefore, electric power system can supply electricity more effectively by selecting power system according to <b>DENP</b>. <b>VEF</b> automatically allocates each power supply system according to <b>DENPI</b> of each power supply system. As this function has a unique structure, it can be extensively applied to new electricity generation systems in various categories of vehicles.</div> <div class="htmlview paragraph"><b>VEF</b> has been evaluated with a test vehicle, and the results show that this structure is applicable to a real vehicle and the running cost of electricity is improved 30% compared to a conventional system.</div>