Simulation Model Of Power System Research Articles

Research on modeling and control strategy of zero-carbon hybrid power system based on the ammonia-hydrogen engine

In the context of carbon neutrality, high efficiency, low carbon, and zero environmental impact have become an essential development direction of internal combustion engines (ICEs). Hydrogen energy has the advantage of having a high calorific value. It also has zero carbon emissions and is considered one of the significant alternative fuels for ICEs. Moreover, ammonia has a high octane number and has an anti-knock effect, which facilitates the mitigation of knock in hydrogen ICEs and potentially mitigates the negative impact of knock on engine volume power. Scholars have carried out some explorations on ammonia-hydrogen ICEs (AHICE), which have been applied in marine power systems. It is anticipated that AHICE will become one of the most significant development directions in the field of vehicle power systems in the future. However, there are still some problems with using AHICEs in passenger cars. The proposed work presented a zero-carbon hybrid power system based on an AHICE. Specifically, the external characteristics curve and power output boundary were obtained by bench experiments of the ICE under wide open throttle (WOT) conditions and diverse engine speeds and λ. Indeed, a hybrid system model consisting of an AHICE and a power battery was built where the AHICE was used to respond to the demanded power and the power battery was used to provide additional power and store the electrical energy converted from braking. Incidentally, an engine control strategy was developed to expand the knock limit and power boundary by dynamically adjusting the ammonia-hydrogen volume ratio. Finally, a hybrid power system simulation model was established based on MATLAB/Simulink. The CLTC-P and WLTC simulation results demonstrated that the zero-carbon hybrid system which comprised AHICE and power battery can work in the high efficiency area. The AHICE demonstrates lower fuel consumption while satisfying power requirements. This work provides a promising route to zero-carbon hybrid technology for the passenger car industry facing the challenge of carbon neutrality.

A Low-Frequency Oscillation Suppression Method for Regional Interconnected Power Systems with High-Permeability Wind Power.

With the integration of large-scale wind power into the power grid, the impact on system stability, especially the issue of low-frequency oscillations caused by small disturbances, is becoming increasingly prominent. Therefore, this paper proposes a damping quantitative analysis method for regional interconnected power systems incorporating large-scale wind power. Using the cross-entropy particle swarm optimization (CE-PSO) algorithm, the control parameters of wind turbines are optimized to suppress low-frequency oscillations in interconnected systems. The method begins with the state equation of the interconnected power system in two regions; it deduces the characteristic polynomial of the interconnected system, including wind farms, and takes into account the influence of wind power integration on the electrical connectivity of the system. Subsequently, the influence of wind turbine control parameters on the system is quantified, and a quantitative analysis model of the impact of wind power integration on system damping characteristics is constructed. Based on this, an optimization model for wind turbine control parameters is established, and the CE-PSO algorithm is utilized to achieve suppression of low-frequency oscillations in interconnected power grids with wind power integration. Finally, the accuracy and effectiveness of the proposed method are verified through a typical electromagnetic transient simulation model of the two-region interconnected power system.

Droop Frequency Limit Control and Its Parameter Optimization in VSC-HVDC Interconnected Power Grids

With the gradual emergence of trends such as the asynchronous interconnection of power grids and the increasing penetration of renewable energy, the issues of ultra-low-frequency oscillations and low-frequency stability in power grids have become more prominent, posing serious challenges to the safety and stability of systems. The voltage-source converter-based HVDC (VSC-HVDC) interconnection is an effective solution to the frequency stability problems faced by regional power grids. VSC-HVDC can participate in system frequency stability control through a frequency limit controller (FLC). This paper first analyses the basic principles of how VSC-HVDC participates in system frequency stability control. Then, in response to the frequency stability control requirements of the sending and receiving power systems, a droop FLC strategy is designed. Furthermore, a multi-objective optimization method for the parameters of the droop FLC is proposed. Finally, a large-scale electromagnetic transient simulation model of the VSC-HVDC interconnected power system is constructed to verify the effectiveness of the proposed droop FLC method.

Novel Fault Protection Method for Flexible DC Power Systems

A fault protection method is proposed for flexible direct-current (DC) power systems based on the cosine similarity of currents in current-limiting reactors. The typical characteristics of external and internal faults in a flexible DC power system were analyzed. The principles of cosine similarity and the fault current characteristics of current-limiting reactors were used to distinguish between internal and external faults. The ratio of the average positive and negative voltages of the current-limiting reactor was then used to distinguish the fault types and fault line. Finally, a simulation model of a circular flexible DC power system was constructed using MATLAB/Simulink software (2018b). The simulation results show that the proposed protection scheme can quickly and accurately identify the location and type of faults, and has a strong ability to withstand fault resistance and is less affected by distributed capacitance, noise, and communication delay.

Development pathway and influencing factors of hydrogen energy storage accommodating renewable energy growth

Hydrogen energy is considered an important energy storage mode with medium- and long-term cross-seasonal storage capabilities in scenarios with high penetration of renewable energy (RE). However, there is a lack of research regarding the appropriate scale of hydrogen energy storage (HES) considering different RE power generation scenarios. In response to this gap, the present study aims to establish a power system simulation model to analyze the development pathway of HES while accommodating RE growth with a minimum cost constraint for a power system operation. The impacts of carbon trading prices, advances in HES technology, and RE resource endowment on HES development are also investigated. The findings indicate that the total available solar energy resources in China are 46.94TW, and the total available wind energy resources are 9.52TW. When the share of RE generation reaches 44.33–54.78 % of total power generation, the utilization of HES for balancing power system is advantageous in reducing the overall system costs. Looking ahead to 2060, the year when China is projected to achieve its carbon-neutrality goal, RE is estimated to reach 63.12–91.1 % of total power generation. Consequently, the HES in each province is estimated to contribute to 3.58–18.02 % of total electricity consumption. Provinces with more abundant wind resources relative to solar resources are expected to have a 36.43 % higher demand for HES.

Equivalent Minimum Hydrogen Consumption of Fuzzy Control-Based Fuel Cells: Exploration of Energy Management Strategies for Ships

Aiming to solve the problems of insufficient dynamic responses, the large loss of energy storage life of a single power cell, and the large fluctuation in DC (direct current) bus voltage in fuel cell vessels, this study takes a certain type of fuel cell ferry as the research object and proposes an improved equivalent minimum hydrogen consumption energy management strategy, based on fuzzy logic control. First, a hybrid power system including a fuel cell, a lithium–iron–phosphate battery, and a supercapacitor is proposed, with the simulation of the power system of the modified mother ship. Second, a power system simulation model and a double-closed-loop PI (proportion integration) control model are established in MATLAB/Simulink to design the equivalent hydrogen consumption model and fuzzy logic control strategy. The simulation results show that, under the premise of meeting the load requirements, the control strategy designed in this paper improves the Li-ion battery’s power, the Li-ion battery’s SOC (state of charge), the bus voltage stability, and the equivalent hydrogen consumption significantly, compared with those before optimization, which improves the stability and economy of the power system and has certain practical engineering value.

Performance monitoring and redesign of power system stabilizers based on system identification techniques

To maintain stable power system operation, damping control systems are used in conventional power plants, known as Power System Stabilizers (PSS). However, to derive suitable controller parameters, the current methods require dynamic models that are difficult to maintain and update, and in some cases, might not be available. This makes it challenging for grid operators to maintain system stability when the system is under stringent operating conditions or undergoes the loss of major transmission corridors, which would require a new stabilizer design to provide adequate damping.Leveraging the availability of real-time measurements and “probing” technologies, this paper provides a complementary approach that does not require power system simulation models, but is based on system identification techniques that allow to derive simple and accurate models based on data collected on the system. The proposed method allows to monitor the performance of damping controllers and even to perform redesign based on the models derived with system identification. The resulting redesign could be used to update PSS parameters and improve damping without the need of removing existing damping control systems from service.

МОДЕЛЬ ЗБЕРЕЖЕННЯ ПРАЦЕЗДАТНОСТІ ЕЛЕКТРОЕНЕРГЕТИЧНОЇ СИСТЕМИ ЗА УМОВИ ЇЇ НЕБАЛАНСУ

Abstract. The dynamic frequency characteristic of the electric power system in the case of imbalance as a result of a change in generating capacity and the absence of a reserve is constructed. A simulation model of the electric power system has been developed based on object-oriented analysis, which makes it possible to analyze the operation and reaction of the electric power system as a result of the impact of disturbances to ensure the possibility of system operability under certified conditions. As a simulation model, an information model and diagrams of transitions to the states of objects were made, reflecting the interaction of objects, which are an abstract reflection of real electrical installations of the power system. Keywords: power system, operability, frequency regulation, disturbances, imbalance, simulation model, object-oriented analysis.

A Predictive Out-of-Step Identification Method Based on Wide-Area Velocity-Acceleration Trajectory

Online identification of the transient instability is essential in power system analysis, as it facilitates the grid operator to decide and coordinate system failure correction control actions. The rapid technological development of phasor measurement units (PMUs) provides an opportunity for online transient out-of-step identification in real-time. This paper analyzes the characteristics of angular velocity-acceleration trajectories in detail, and then proposes a predictive transient out-of-step identification method among coherent groups of generators based on the velocity-acceleration trajectory sampled by PMUs. To prove that the method can distinguish the transient out-of-step event following disturbance reliably, a mathematical proof of the criterion extended to multi-machine system is made, and the influences of the exciter and emergency control are taken into consideration to a certain extent. Finally, the effectiveness and predictability of the proposed method are demonstrated on a 39-bus New England test system and two large-scale power system simulation models of China by numerical studies.

A net-zero emissions strategy for China’s power sector using carbon-capture utilization and storage

Decarbonized power systems are critical to mitigate climate change, yet methods to achieve a reliable and resilient near-zero power system are still under exploration. This study develops an hourly power system simulation model considering high-resolution geological constraints for carbon-capture-utilization-and-storage to explore the optimal solution for a reliable and resilient near-zero power system. This is applied to 31 provinces in China by simulating 10,450 scenarios combining different electricity storage durations and interprovincial transmission capacities, with various shares of abated fossil power with carbon-capture-utilization-and-storage. Here, we show that allowing up to 20% abated fossil fuel power generation in the power system could reduce the national total power shortage rate by up to 9.0 percentages in 2050 compared with a zero fossil fuel system. A lowest-cost scenario with 16% abated fossil fuel power generation in the system even causes 2.5% lower investment costs in the network (or $16.8 billion), and also increases system resilience by reducing power shortage during extreme climatic events.

The Design and Simulation of Associated Protection for Low Voltage Shore-to-ship Power Supply System in Inland Port

Due to the complex environmental conditions of inland ports, it is of great significance to adopt associated protection to ensure the safe and reliable operation of the shore-to-ship power supply system. To accurately simulate the operating conditions of the shore-to-ship power supply system, the simulation model of the ship power system is established completely. According to the characteristics of the inland port, the simulation model of the shore-based power supply system is designed and established. Based on the established simulation model of a low voltage shore-to-ship power supply system, to meet its protection requirements of it, an associated protection method including safety interlock, under-voltage protection, and short-circuit protection is proposed. To verify the effectiveness of the associated protection, power faults are set in the shore-to-ship power supply system, and the action of the associated protection during the fault is analyzed by comparing the voltage and current waveforms of the shore-to-ship power supply system with associated protection and unprotected ones. The results show that the associated protection can effectively detect the power failures of the shore-to-ship power supply systems and take timely protection measures to ensure equipment safety.

The Impact of Hydrogen Energy Storage on the Electricity Harvesting

The economics, infrastructure, transportation, and level of living of a country are all influenced by energy. The gap between energy usage and availability is a global issue. Currently, all countries rely on fossil fuels for energy generation, and these fossil fuels are not sustainable. The hydrogen proton exchange membrane fuel cell (PEMFC) power system is both clean and efficient. The fuel delivery system and the PEMFC make up the majority of the PEMFC power system. The lack of an efficient, safe, and cost-effective hydrogen storage system is still a major barrier to its widespread use. Solid hydrogen storage has the large capacity, safety and good reversibility. As a hydrogen source system, the hydrogen supply characteristics affect the characteristics of the PEMFC at the output. In this paper, a mathematical model of a hydrogen source reactor and PEMFC based on chemical absorption/desorption of solid hydrogen storage is established, and a simulation model of a PEMFC power system coupled with solid hydrogen storage is established using MATLAB/SIMULINK software, and the hydrogen supply of the reactor is analyzed in detail. The influence of prominent factors is evaluated. The research results show that the proposed method improved the system performance. At the same time, increasing the PEMFC temperature, increasing the area of the proton exchange membrane and the oxygen supply pressure can increase the output power of the power system.

The impact of diesel operation time constraint on total cost of diesel-based hybrid renewable power system simulation model

This study proposes a simulation model with practical constraints on the use of diesel engine and investigates the impact of adding the constraint of the minimum length of diesel operation time on total cost of hybrid power system, which is designed to supply power for a small village located in the east part of Iran. The results indicated that in the presence of the aforementioned constraint, total cost of hybrid power system increased by shortening diesel generator lifespan and growing diesel fuel consumption. The research did not find any specific uptrend or downtrend in battery lifetime by adding the mentioned constraint into the model. The study outcomes also specified that the surplus power of the hybrid power system inclined in the existence of the minimum length of diesel operation time constraint. The results demonstrated that one hour increment in the minimum length of diesel operation time left a remarkable part of generated renewable power as a surplus power.

Particle Swarm Optimization and Modular Multilevel Converter Communication in Electrical Applications with Machine Learning Algorithm.

As a result of their natural capacity to recover harmonic current and reactive power from alternating current sources, power electronic devices utilized in conjunction with nonlinear loads have the potential to generate significant harmonic problems within the power system when employed in this way. When this occurs, voltage instability occurs, which must be avoided in order to maintain the consistency and dependability of the power system's power flow. With this approach, the series controller has been replaced by a multilevel modular controller in order to improve power handling capability and achieve higher modular levels with minimal distortions. The shunt compensator is the most effective way to achieve an extremely protected energy system as well as righteous steadiness in electric potential difference under a variety of load constraints. The DQ thesis is employed in this proposed converter to separate the harmonic components by establishing reference frame current, which is accomplished by machine learning techniques. As part of the constant mode operation, the PI controller contributes to maintaining the direct current-potential difference, which is given to the PWM generator. Optimization of the values of K p and K i is accomplished by the use of particle swarm optimization (PSO). The construction of this power system simulation model has been made feasible by the use of time-fluctuating characteristics modeling and the MATLAB programming environment. The new (unified power flow controller) UPFC research that has been made available is persuasive in its capacity to reduce distortions and watt-less power components while simultaneously enhancing efficiency and reducing costs.

Active Power Flow Control Using Phase Shifting Transformer and UPFC in AC Transmission Line

Electrical power system is huge interconnected power system to meet the consumer demand without interruption and to maintain the stability, to utilize existing system to their maximum limit within stability limit of the system, to solve the congestion problem and improve the power flow in the line. Phase shifting transformer (PST) is used to control the active power flow in transmission line. This active flow control is obtained by adjusting phase angle of voltages at PST terminal. Unified power flow controller (UPFC) is facts device, it can control both the active and reactive power in transmission line by controlling the line parameter like voltage, phase angle and line impedance there by adjusting the line reactance in real time. The power system simulation model for PST and UPFC are developed in MATLAB. By simulating the model without PST and UPFC and then model with PST and UPFC is simulated to obtain the results. Results are compared for different loading condition to analyze the performance of the system with both the model. Keyword – PST, UPFC, Power flow control, active and reactive power, MATLAB/SIMULINK

Hybrid Electric Vehicle Energy Online Allocation Strategy Based on Fuzzy Reinforcement Learning

Abstract To lessen fuel consumption of hybrid electric vehicle, energy online distribution strategy based on fuzzy reinforcement learning is proposed. Vehicle dynamic model and key component model are built, so that hybrid power system simulation model is given. Energy distribution problem of hybrid electric vehicle is transferred to constrained optimization problem of stochastic dynamic system through modelling, and solving problem based on fuzzy reinforcement learning is put forwarded. Fuzzy reinforcement learning is used to optimize fuzzy inference system real-time, which makes fuzzy inference system adjust with driving cycle adaptively, so that optimal control under any driving cycle come true. Clarified by simulation, fuel consumption under the control of rule-based is 3.89L/km, and it is 3.45L/km under the control of fuzzy reinforcement learsning, which saves 11.31% fuel consumption compared with rule-based. The data above proves validity of fuzzy reinforcement learning on hybrid electric vehicle energy management.

Fault Diagnosis Technology for Ship Electrical Power System

This paper proposes a fault diagnosis method for ship electrical power systems on the basis of an improved convolutional neural network (CNN) to support normal ship operation. First, according to the mathematical model of the ship electrical power system, the simulation model of the ship electrical power system is built using the MATLAB/Simulink simulation software platform in order to understand the normal working state and fault state of the generator and load in the power system. Then, the model is simulated to generate the fault response curve, and the picture dataset of the network model is obtained. Second, a CNN fault diagnosis model is designed using TensorFlow, an open-source tool for deep learning. Finally, network model training is performed, and the optimal diagnosis results of the ship electrical power system are obtained to realize structural parameter optimization and diagnosis. The diagnosis results show that the established simulation model and improved CNN can provide support for fault diagnosis of the ship electrical power system, improve the operation stability and safety of the ship electrical power system, and ensure safety of the crew.

Simulation study on power system short circuit fault based on EMTP

Electromagnetic transient simulation program EMTP is a common simulation commercial software in power system. It can effectively analyze and study power system. In this paper, EMTP is used to build the power system simulation model, and a variety of short-circuit faults in the power system are simulated and analyzed. The results show that the results accord with the actual theory, and the waveform can accurately and intuitively investigate the dynamic characteristics of power system faults. In addition, through the simulation comparison and analysis between different faults, it can be seen that the three-phase short-circuit fault is the most serious fault in the power system, which should be avoided in the actual production and life. This shows that EMTP is a powerful tool for power system simulation research, and provides a reference for the actual equipment selection requirements of the project.

Integration of fuel cells into an off-grid hybrid system using wave and solar energy

This paper discusses the dynamic modeling and control conducted on a novel hybrid energy system comprising a fuel cell (FC), that can be viably integrated with several renewable energy sources of different natures such as solar and wave energy, with battery banks used as backup power sources for electric power production. Furthermore, it extracts the full potential of the three sources using a novel, fast, and highly accurate controller based on buck-boost technology that concurrently controls the maximum power of the energy conversion systems utilized. The battery bank will directly feed the system when there is a problem with one of the sources. These sources have different characteristics for testing the developed controller under different conditions and developing a reliable energy system. Wave energy is currently considered to be one of the most promising renewable sources. It has seen significant recent development to increase its efficiency by incorporating new technologies, such as Savonius turbines, which had previously been used to generate wind energy. For the present study, a two-stage Savonius rotor was used in the wave generator. The simulation model of the entire hybrid power system was produced using MATLAB/Simulink and experimentally verified in a remote area under different weather conditions. The controller was successful in keeping the voltage of the hybrid system constant at 11.8 V near the desired value of 12 V, with an efficiency of 98%.

Analysis on voltage characteristics of distribution network considering rolling mill load and Research on control measures

In view of the voltage fluctuation and flicker of distribution network caused by rolling mill type typical load in some distribution networks and the reduction of power quality of power grid, it is necessary to analyze the voltage characteristics of distribution network, and adopt an effective governance measure to suppress harmonics in distribution network and improve power quality of power grid. The mathematical models of several typical loads corrected based on the measured data are established, and the influence radiation range of the corrected rolling mill load model on the distribution network voltage is analyzed, and a SVC (static var compensator) governance measure with SOGI phase-locked strategy is adopted for governance. Finally, combined with the actual operation parameters of a substation of State Grid, the power system simulation model is built by using simulation software, and the effectiveness of the governance measures adopted in this paper is verified by simulation analysis.