scholarly journals Determination of optimal operating modes of the Ukrainian power system when covering the daily schedule of electrical loads, ensuring the necessary volumes of redundancy and using storage capacities

2020 ◽  
Vol 2020 (4) ◽  
pp. 33-44
Author(s):  
V.A. Denisov ◽  

We propose a model of mathematical programming with integer variables, the use of which provides a search for the optimal modes of redundancy and loading of storage capacities of the power plants in Ukraine with covering the daily schedule of electrical loads. The main purpose of this work is to create a tool for studying the possibilities of optimized dispatching of generating capacities of thermal power plants, as well as generating and reserve capacities of high-power storage units within the IPS of Ukraine, the limits of permissible values of the parameters of generating and storing capacities, at which stable balanced operation of the energy system is possible. The model enables one to determine the optimal modes of using generating and storing capacities for covering the schedule of electrical loads without using storage and with using storage at different values of the total installed and peak power of SES and wind farms. The model takes into account the specific features of the operation of reserve and storage capacities of the Ukrainian energy system – the maximal possibilities for change in the power of storage and generation of electricity units of the Ukrainian energy system and possibility to provide support for frequency recovery reserves (secondary regulation) at a given level, located at thermal power plants, PSPPS, and high-power storage facilities. The model enables us to study the possibilities of optimized dispatching of the components of the IPS of Ukraine, the limits of permissible values of parameters of generating and storing capacities, at which stable balanced operation of the energy system is possible and can be applied in the tasks of forming forecast balances covering daily schedules of electric loads to study the prospects for short- and long-term development of storage and generating capacities of the national energy system, which is relevant under conditions of rapid growth of the capacity of wind and solar power plants. The model is implemented in the mathprog algebraic modeling language, which is a component of the Solver Studio optimization package and uses the COIN-OR PuLP modeling language. Keywords: power system, daily load schedule of the power system, reserve and storage capacities, model of mathematical programming with integer variables, optimal solution

2020 ◽  
Vol 2020 (4) ◽  
pp. 33-44
Author(s):  
V.A. Denisov ◽  

We propose a model of mathematical programming with integer variables, the use of which provides a search for the optimal modes of redundancy and loading of storage capacities of the power plants in Ukraine with covering the daily schedule of electrical loads. The main purpose of this work is to create a tool for studying the possibilities of optimized dispatching of generating capacities of thermal power plants, as well as generating and reserve capacities of high-power storage units within the IPS of Ukraine, the limits of permissible values of the parameters of generating and storing capacities, at which stable balanced operation of the energy system is possible. The model enables one to determine the optimal modes of using generating and storing capacities for covering the schedule of electrical loads without using storage and with using storage at different values of the total installed and peak power of SES and wind farms. The model takes into account the specific features of the operation of reserve and storage capacities of the Ukrainian energy system – the maximal possibilities for change in the power of storage and generation of electricity units of the Ukrainian energy system and possibility to provide support for frequency recovery reserves (secondary regulation) at a given level, located at thermal power plants, PSPPS, and high-power storage facilities. The model enables us to study the possibilities of optimized dispatching of the components of the IPS of Ukraine, the limits of permissible values of parameters of generating and storing capacities, at which stable balanced operation of the energy system is possible and can be applied in the tasks of forming forecast balances covering daily schedules of electric loads to study the prospects for short- and long-term development of storage and generating capacities of the national energy system, which is relevant under conditions of rapid growth of the capacity of wind and solar power plants. The model is implemented in the mathprog algebraic modeling language, which is a component of the Solver Studio optimization package and uses the COIN-OR PuLP modeling language. Keywords: power system, daily load schedule of the power system, reserve and storage capacities, model of mathematical programming with integer variables, optimal solution


2021 ◽  
Vol 24 (4) ◽  
pp. 109-115
Author(s):  
Vyacheslav Valerievich Guryev ◽  
Vladimir Vyacheslavovich Kuvshinov ◽  
Boris Anatolevich Yakimovich

The Crimean Peninsula is the flagship of the development of renewable energy, as it is not only an actively developing region, but also a resort center. The energy complex of the Crimean Peninsula in recent years has increased due to the construction of new power plants (Balaklava TPP and Tavricheskaya TPP) with a total capacity of 940 MW, as well as the construction of new 220 and 330 kV transmission lines, which ensured that the peninsula’s power supply deficit was covered. A review of the regional development and use of renewable energy sources is carried out. Based on the data obtained, an analysis is made of the problems and prospects for the development of renewable energy in the region. The development of renewable energy for the Crimean Peninsula plays an important role in order to achieve environmental safety and develop the economic potential of the region. The paper substantiates the priority use of renewable energy in the region, as well as the solution of emerging problems with an increase in the share of renewable energy in the total generation. The appearance of excess electricity in the power system and the possibility of balancing the generated power of renewable energy and thermal power plants, while reducing the cost of electricity. Investment attractiveness and active population growth in the region leads to an increase in generating capacity and an increase in the maneuverability of the energy system with a significant impact of RES. The efficiency of renewable energy in the energy system, the world experience in managing renewable energy generation, the actual impact of renewable energy on the energy system in conditions of electricity shortage, and forecast work schedules of the SES wind farm provided by the electric power industry entities in the assigned way are taken into account when forming the dispatch schedule and are accepted at the request of the subject. The available experience of existing SES in the power system of the Republic of Crimea and the city of Sevastopol requires additional research, including through field testing of generating equipment. Further full-scale tests should be carried out under the conditions of a real electric power mode of the power system, which requires the introduction of modern information technologies that ensure the exchange of technological information and the implementation of appropriate control actions. The work is underway to create a regulatory framework for the control of renewable energy source operation.


2020 ◽  
Vol 6 (2) ◽  
pp. 104-109
Author(s):  
Kostiantyn Pokrovskyi ◽  
◽  
Andriy Muzychak

The widespread applying of electrical grids with voltage classes 330 and 750 kV with powerful units of nuclear and heat power plants creates a set of problems with normal modes ensuring in the Ukrainian energy system. Due to sufficiently great transverse capacitance of such overhead lines, significant amounts of reactive power excess are possible in the system. This phenomenon manifests itself especially in the load reduction hours in the power system through the visible voltage levels deviation at the energy-generating nodes in an upward direction. The application of asynchronized turbogenerators with the ability to work in asynchronous mode could solve the problem of reactive power excesses in the energy-generating nodes during load reduction hours in the power system due to their possibility of deep reactive power consumption. The paper presents the calculated results of the asynchronous modes coordinates for an asynchronized turbogenerator with a capacity 1000 MW based on the parameters of the equivalent circuit, taking into account possible generator stator voltage deviations within ±10%. The influence of voltage deviations on the asynchronous modes coordinates is shown. Due to the obtained characteristics, it is possible to perform engineering estimations of the possible asynchronous mode applying for the asynchronized generator under conditions of nuclear and thermal power plants and taking into account possible voltage deviations.


Author(s):  
M.V. Cherniavskyi

The structure of electricity cost formation for consumers, including depending on the cost of TPP generation, «green» energy and other sources, is investigated, and the main conditions of the efficient regulatory function fulfillment in the power system by thermal power generation in the conditions of Ukraine's course on carbon-free energy are formulated. It is shown that excessive electricity losses in networks and, especially, accelerated increase of the share of «green» generation, much more expensive than nuclear, hydro and thermal, mainly contribute to the growth of electricity costs for non-household consumers and the need to raise tariffs for the population. This accelerated increase directly contradicts the Paris Climate Agreement, according to which plans to reduce Ukraine’s greenhouse gas emissions must be developed taking into account available energy resources and without harming its own economy. The dependences of the specific fuel consumption on the average load and the frequency of start-stops of units are found and it is shown that the increased specific fuel consumption on coal TPPs is an inevitable payment for their use as regulating capacities of UES of Ukraine. In this case, the higher the proportion of «green» generation and a smaller proportion of generating thermal power plants, especially increasing specific fuel consumption. It is proved that in the conditions of growth of the share of «green» generation in Ukraine the share of production of pulverized coal thermal power plants should be kept at the level of not less than 30 % of the total electricity generation. It is substantiated that a necessary condition for coal generation to perform a proper regulatory role in the power system is to introduce both environmental and technical measures, namely — reducing the suction of cold air to the furnace and other boiler elements, restoring condensers and cooling systems, etc. An important factor in reducing the average level of specific fuel consumption is also the reduction of coal burn-out at thermal power plants, where it still remains significant, due to the transfer of power units to the combustion of bituminous coal concentrate. Bibl. 12, Fig. 5, Tab. 5.


2016 ◽  
Vol 67 (4) ◽  
pp. 234-245 ◽  
Author(s):  
Goran Knežević ◽  
Zoran Baus ◽  
Srete Nikolovski

Abstract In this paper short-term planning algorithm for hybrid power system consist of different types of cascade hydropower plants (run-of-the river, pumped storage, conventional), thermal power plants (coal-fired power plants, combined cycle gas-fired power plants) and wind farms is presented. The optimization process provides a joint bid of the hybrid system, and thus making the operation schedule of hydro and thermal power plants, the operation condition of pumped-storage hydropower plants with the aim of maximizing profits on day ahead market, according to expected hourly electricity prices, the expected local water inflow in certain hydropower plants, and the expected production of electrical energy from the wind farm, taking into account previously contracted bilateral agreement for electricity generation. Optimization process is formulated as hourly-discretized mixed integer linear optimization problem. Optimization model is applied on the case study in order to show general features of the developed model.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7281
Author(s):  
Felipe Nazaré ◽  
Luiz Barroso ◽  
Bernardo Bezerra

The main challenge with the penetration of variable renewable energy (VRE) in thermal-dominated systems has been the increase in the need for operating reserves, relying on dispatchable and flexible resources. In the case of hydro-dominated systems, the cost-effective flexibility provided by hydro-plants facilitates the penetration of VRE, but the compounded production variability of these resources challenges the integration of baseload gas-fired plants. The Brazilian power system illustrates this situation, in which the development of large associated gas fields economically depends on the operation of gas-fired plants. Given the current competitiveness of VRE, a natural question is the economic value and tradeoffs for expanding the system opting between baseload gas-fired generation and VRE in an already flexible hydropower system. This paper presents a methodology based on a multi-stage and stochastic capacity expansion model to estimate the optimal mix of baseload thermal power plants and VRE additions considering their contributions for security of supply, which includes peak, energy, and operating reserves, which are endogenously defined in a time-varying and sized in a dynamic way as well as adequacy constraints. The presented model calculates the optimal decision plan, allowing for the estimation of the economical tradeoffs between baseload gas and VRE supply considering their value for the required services to the system. This allows for a comparison between the integration costs of these technologies on the same basis, thus helping policymakers and system planners to better decide on the best way to integrate the gas resources in an electricity industry increasingly renewable. A case study based on a real industrial application is presented for the Brazilian power system.


2021 ◽  
Vol 264 ◽  
pp. 04057
Author(s):  
Boboraim Urishev ◽  
Muradilla Mukhammadiev ◽  
Abdurauf Abduaziz uulu ◽  
Hojiakbar Murodov

Information about the problems arising from the uneven production and consumption of energy in power systems, including in the power system of the Republic of Uzbekistan, is given on the example of a daily electrical load schedule. It is noted that to successfully solve these problems, energy is accumulated in the hours of minimum consumption so that it can be used in peak hours with high consumption, and for this purpose, pumped storage power plants are used. A diagram of hydraulic energy storage is given at large pumping stations used to accumulate water in the upper reservoir in hours of minimum loads, and the accumulated volume of water is directed to generate energy, which can be used by pumping stations to supply additional water to its consumers, replenishing its losses in hours of hydraulic energy storage. The method of selection and optimization of the main parameters of this complex, based on minimizing fuel consumption in power plants while limiting the amount of accumulated energy based on the capabilities of water and energy resources of pumping stations, is presented. The calculations using the example of the Syrdarya thermal power plant show that with the integration of five nearby pumping stations into the process of energy storage and generation, significant cost savings are achieved, and the daily load schedule is significantly leveled.


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