Hybrid Real-Time Power System Simulator Research Articles

A novel approach to validation of a positive-sequence modeling of a converter-interfaced generation with hydrogen energy storage in practical power systems

The most important hydrogen energy storage technologies, developed between 1974 and 2022, now enable the quality operation of global power grids that integrate alternative energy facilities (wind power, solar power, geothermal power, etc.). With the continuous large-scale penetration of converter-interfaced generation (CIG), based on the combined use of renewable energy sources (RES) and hydrogen energy storage systems (ESS), into practical power systems, the dynamic characteristics of the latter change significantly. New challenges with the power system control and stability arise due to the specific CIG properties. A positive-sequence time-domain simulation is frequently used to solve them. However, the known simplifications and limitations are inevitably applied in case of such simulation. These become critical for the CIG with RES and hydrogen ESS models due to their fast dynamics. Therefore, the validation of such simulation results becomes relevant. This paper proposes a novel validation approach based on the use of a benchmark tool Hybrid Real-Time Power System Simulator (HRTSim) instead of field measurements. A major feature of the proposed approach is the possibility of a guaranteed validation of the benchmark tool using any state of the modeled power system. A hybrid implementation of a detailed three-phase model of CIG is also developed for the HRTSim, which provides an adequate simulation of the full range of dynamic processes. The results of validation of a positive-sequence simulation of a practical power system with CIG, which includes both RES and hydrogen ESS, using the developed approach presented in this paper have allowed to identify the causes of calculation errors, as well as factors affecting them.

A Hybrid Model of Photovoltaic Power Stations for Model Ling Tasks of Large Power Systems

Renewable energy sources are being actively penetrated in the global energy sector, with the main growth being achieved by new photovoltaic power stations. At the same time, the influence of photovoltaic power stations on the operation of power systems is known. This is primarily due to the inconstancy of the weather, which leads to a decrease in the output of each specific photovoltaic panel and power station as a whole. To study the effect of partial shading of photovoltaic panels on the parameters of its operation, various models of the current-voltage characteristics of photovoltaic cells are used in the world, while detailed two-diode models show the best results. The use of detailed models allows to get complete information about the processes in a variety of photovoltaic panels of a power station, as well as other elements of it, such as a voltage converter. This makes it possible to assess the impact of these processes on the external power system. However, for detailed modelling of large photovoltaic power stations as part of power systems, it is necessary to use powerful software and hardware systems. Such systems include the Hybrid real-time power system simulator. This simulator is a multiprocessor installation that provides a solution to the aggregate model of the power system through the use of three approaches to modelling: digital, analogue and physical. The article presents the results of experimental studies of software and hardware tools for modelling a photovoltaic power station, developed on the basis of a hybrid approach to modelling electric power systems.

Novel approach for relays tuning using detailed mathematical model of electric power system

The correct operation of relay protection (RP) devices largely determines the security of electric power systems (EPS). The key point that in turn determines the behavior of protection in various emergency modes is a determination of their settings. The existing methodologies and tools often do not allow to provide RP settings adequate to the practical conditions of their functioning. This statement is confirmed by the statistics of faults in EPSs. The main reason for this issue is the inability to reliably reproduce transients in EPS via the software programs used in practice to calculate the RP settings. The Hybrid Real-Time Power System Simulator (HRTSim), developed by the authors, allows to reliably reproduce the entire range of normal and emergency modes and processes in EPS of any scale, topology and configuration by using detailed three-phase models of all power system components. Taking into account this possibility and features of the HRTSim, the task of detailed modeling of RP devices, including instrument current and voltage transformers, becomes relevant. The implemented special tools for RP modeling and the HRTSim in general allow to develop a new methodology for RP tuning. At the same time, the typical elements – relays – can be identified for each type of RP that determine their operation algorithm. This paper presents an analysis of the main relays of the most modern microprocessor-based RP devices and proposed principles of their tuning. The developed approach allows to adapt the RP settings to the practical conditions of their functioning in EPSs and to minimize the probability of RP maloperation.

Settings determination for numerical transformer differential protection via its detailed mathematical model

Currently, an issue of relay protection (RP) settings determination that ensures its correct operation in electric power systems (EPSs) has not been resolved completely. The main reason for this is the lack of methods and tools for adequate consideration of transients during a fault existence for RP settings calculation. In this study, a novel approach for RP settings determination is presented. Its main feature is the application of detailed mathematical models reproducing simultaneously processes in the entire set of elements in the RP scheme, including instrumental transformers, and in large-scale EPS mathematical model as a whole. This key feature can be achieved via the hybrid power system simulator - hybrid real-time power system simulator - implementing a methodically accurate analogue-digital solution of the EPS mathematical model. The numerical transformer differential protection (NTDP) based on this approach was set up via the standard dual-slope tripping characteristic. Also, a novel approach to the formation of the tripping characteristic is proposed. The key feature of this approach is applying a flexible curve that enveloping all fault characteristics I diff = f ( I rest ) of those modes in which the NTDP should not trip.

Potential Application of HRTSim for Comprehensive Simulation of Large-Scale Power Systems with Distributed Generation

AbstractCurrently, the number of distributed generation (DG) objects in the world is growing mainly due to renewable energy sources (RES). However, the integration of a large volume of DG based on RES into existing electric power systems (EPS) is associated with a number of significant problems. For a comprehensive study and solution of these problems, it is necessary to carry out detailed simulation of real EPS, which is not always feasible with the help of existing tools. Therefore, the article proposes the use of an alternative solution – the Hybrid Real-Time Power System Simulator (HRTSim). To confirm the properties and capabilities of the HRTSim, the simulation results of a test scheme obtained using the HRTSim and the widely used digital hardware-software complex RTDS were compared. The results of a comprehensive comparison in both complexes confirmed the adequacy of information about the processes in equipment and EPS as a whole, obtained by the HRTSim. Thus, it is proved that further use the HRTSim as a tool for detailed and adequate simulation of real EPS with DG will provide complete and reliable information about normal and abnormal quasi-steady-state and transient processes, which is necessary for reliable and efficient design, research and subsequent operation of EPS with DG.

The novel approach for electric power system simulation tools validation

The reliability and efficiency of electric power system (EPS) operation depends on the adequacy of the information about processes in the EPS. The complexity of obtaining this information lies in the need to use large-scale EPS mathematical model for calculations. Within the framework of numerical integration, a satisfactory solution of such model is hardly to be ensured; consequently, the simplifications and limitations are applied. In this regard, every obtained solution should be validated. The most reliable way of validation is to compare simulation results with field data. However, it is not always possible to receive the necessary amount of field data. The paper proposes an alternative approach for validation: the adequate reference model (RM) usage instead of field data. The prototype of hybrid real-time power system simulator having the necessary properties and capabilities is used as the RM in this paper. The adequacy of proposed approach is illustrated by the fragments of the experimental studies.

Hybrid Real-Time Simulator of Large-Scale Power Systems

This paper is devoted to the description of a new approach for large-scale electric power systems (EPS) simulation, so-called hybrid simulation approach. The design and research of EPS require solving a large number of non-trivial tasks. Due to the well-known EPS specificity, mathematical modeling is the only way to proceed. According to the hybrid approach, several simulation techniques (analogue, digital, and physical) are used to achieve the best results. An analogue part provides the elimination of methodological integration error, which appears in a case of numerical methods usage. A digital part allows the realization of control and parameter changing algorithms on software level. In a physical part, the connection and switching of modeled elements are provided in a way as in real EPS. In addition, the paper presents hardware features of the simulator—hybrid real-time power system simulator (HRTSim), which is an alternative to the digital simulators currently used. The important part of this paper is the result of comparative analysis of transient processes oscillograms obtained by HRTSim and real disturbance recorders in Tomsk region power system, as well as HRTSim and real-time digital simulator.

Application of hybrid real‐time power system simulator for research and setting a momentary and sustained fast turbine valving control

The stability of electric power system (EPS) insures energy security of consumers. Therefore, saving the stability of EPS is the main task for professionals around the world. For its solution, a variety of activities is used. This publication deals with the description of the authors' experience for solving the task in the Tyumen power system. The hybrid real-time power system simulator (HRTSim) developed in Tomsk Polytechnic University was used as a platform for research carrying out. The study presents the research result fragments of the momentary and sustained fast turbine valving control (FTVC) which is one of the most effective ways of an automatic emergency control of power units in the thermal power station. Using the simulator HRTSim, one of the greatest challenges of electric power industry in Russia has been solved, i.e. FTVC adequate setting of the power units in the thermal power station Surgut GRES-2 in the Tyumen power system. An FTVC operation largely determines the reliability and stability of the EPS. Therefore, an incorrect setting may result in substantial disturbance or disruption of the stability that already occurred in the past. The adequacy of turbine and FTVC simulations is verified by comparing it with the real data.

The concept of usage HRTSIM as a device for setting and certification of AVR

This paper presents the analysis of application Hybrid Real-Time Power System Simulator (HRTSim), developed at National Research Tomsk Polytechnic University, as a device for setting and certification of automatic voltage regulators (AVR) for synchronous generators. The simulation results demonstrate that the proposed hardware-software complex (HSC) can be used for presented aim.

Research of the surge voltage protection by means of Hybrid Real-Time Power System Simulator

The article considers the simulation of surge voltage protection. A functional diagram of this protection model and the means by which the researches were made are presented. The results are the oscillograms of the surge voltage protection operation for the generator.

Approach in the modeling of wind turbines for power system stability studies and evaluation of their impact on electric power systems

Wind power - one the fastest evolving in renewable energy industry. From year to year the share of wind energy in power systems are increasing as well as increasing the size of wind farms. A large-scale wind farms that produce hundreds of megawatts of electricity have a serious impact on the power grid. This paper discusses proposed approaches to modeling wind farms using the Hybrid Real-Time Power System Simulator (HRTSim), to study stability and transient processes in electric power systems.

Use of a Hybrid Power System Simulator for the Dispatchers Exercise

The article presents a Dispatcher Training Simulator (DTS) based on the Hybrid Real-Time Power System Simulator (HRTSim). The main DTS advantage is the real-time circuit-mode states control of the electric power systems (EPS) equipment, including isolated-phase control. This DTS operates in all EPS modes: normal, emergency, and post-emergency. It is achieved by hybrid simulation. The dispatcher training simulator requires specialist software, structure of which is described in this article. In additional, implementation of this DTS for Tyumen EPS, Russia was demonstrated.  Finally, the implementation results are given to demonstrate the efficiency of the DTS application for the dispatchers’ skills upgrading.

Application of Hybrid Real-Time Power System Simulator for Designing and Researching of Relay Protection and Automation

Development, research and operation of smart grids (SG) with active-adaptive networks (AAS) are actual tasks for today. Planned integration of high-speed FACTS devices greatly complicates complex dynamic properties of power systems. As a result the operating conditions of equipment of power systems are significantly changing. Such situation creates the new actual problem of development and research of relay protection and automation (RPA) which will be able to adequately operate in the SGs and adapt to its regimes. Effectiveness of solution of the problem depends on using tools - different simulators of electric power systems. Analysis of the most famous and widely exploited simulators led to the conclusion about the impossibility of using them for solution of the mentioned problem. In Tomsk Polytechnic University developed the prototype of hybrid multiprocessor software and hardware system - Hybrid Real-Time Power System Simulator (HRTSim). Because of its unique features this simulator can be used for solution of mentioned tasks. This article introduces the concept of development and research of relay protection and automation with usage of HRTSim.

Testbed Based on Hybrid Real-Time Power System Simulator for Setting up and Testing of Protection and Control Systems

In this article we will focus on creating of testbed based on hybrid real-time power system simulator (HRTSim) for setting up and testing of relay protection (RP), automatic (AS) and control systems (CS), as well as the opportunities and prospects of its application. The simulator has physical outputs, which allows using it for close-loop testing of RP, AS and CS. Physical currents and voltages generated in the simulator during a simulation process can be transmitted to the analog inputs of tested device by means of external amplifiers. There are no restrictions on the dimension of the simulated power system and time interval for HRTSim. These opportunities and usage of adequate models of primary and auxiliary power system equipment allows reducing the number of possible equivalenting and creating as closely as possible to the real conditions for setting up and testing of any RP, AS and CS, including wide-area protection and control systems.