A dual mode traction power supply system (TPSS), as a high-efficiency transportation approach, is composed of a mainline railway (AC traction power supply system) and an urban railway (DC traction power supply system)...
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A dual mode traction power supply system (TPSS), as a high-efficiency transportation approach, is composed of a mainline railway (AC traction power supply system) and an urban railway (DC traction power supply system). However, due to the neutral sections, the power from the two systems has been isolated, resulting in a low utilization rate of regenerative braking energy (RBE). The powerflow from the two systems can not be managed cooperatively, causing high electricity bills. Therefore, this paper proposes a dual mode based energy router (DMER), which provides a path for energy interaction between two systems through multi-terminal converters. The proposed DMER integrates a hybrid energy storage system (HESS) and an energy feedback system (EFS) to recycle RBE. Moreover, a hierarchical control strategy is presented. The upper control layer is an optimized operation model, which takes the state of charge (SoC), energy conservation, and the other parameters as constraints to utilize more RBE and achieve the minimum daily operation cost of substations. The lower control layer identifies the control strategy for multiple converters to ensure the stable operation and dynamic response of DMER. Finally, the effectiveness of the topology and control strategy is verified using field load data and experiments.
Transmission sections are critical components of regional interconnected power grids, and the reasonable distribution of powerflow on these sections is significant for the stable and secure operation of the system. T...
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ISBN:
(纸本)9798350375145;9798350375138
Transmission sections are critical components of regional interconnected power grids, and the reasonable distribution of powerflow on these sections is significant for the stable and secure operation of the system. The Thyristor Controlled Phase Shifting Transformer (TCPST), as a novel Flexible AC Transmission System (FACTS) device, can effectively improve powerflow distribution on transmission sections. This paper focuses on the application of TCPST in optimizing powerflow on transmission sections, selecting the load balancing degree and section losses as the control objectives for TCPST. A control strategy for optimizing powerflow on transmission sections using TCPST is proposed and its effectiveness is verified through simulations on the PSCAD/EMTDC platform. The simulation results demonstrate that the proposed control strategy provides reasonable control objectives for TCPST applications in transmission sections, thereby improving powerflow distribution and enhancing the reliability and safety of section operation.
In the optimal powerflow problem of AC-DC hybrid power system including wind power and other new energy sources, if the probability distribution information of uncertain variables can be obtained, the stochastic opti...
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In order to reduce the huge network loss due to powerflow back-feed and transfer under a high percentage of photovoltaic (PV) access, a comparative study on the impact of Soft Open Point (SOP), Rotary powerflow Cont...
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In order to reduce the huge network loss due to powerflow back-feed and transfer under a high percentage of photovoltaic (PV) access, a comparative study on the impact of Soft Open Point (SOP), Rotary powerflow Controller (RPFC), Capacitor Banks (CB), and flexible load access on the distribution network is carried out. Firstly, the second-order cone model for active distribution network coordination optimization based on SOP or RPFC flexible interconnection is established with the lowest network loss of distribution network as the goal;secondly, the second-order cone model of distribution network under different configuration schemes is solved separately under the improved IEEE 33-bus distribution network;finally, the optimal loss reduction strategy is obtained by quantitative analysis.
Optimizing steady-state powerflow (PF) in Smart Grids (SGs) poses a significant challenge due to the complex interplay of various energy sources, converters, and control mechanisms. Conventional optimization methods ...
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Optimizing steady-state powerflow (PF) in Smart Grids (SGs) poses a significant challenge due to the complex interplay of various energy sources, converters, and control mechanisms. Conventional optimization methods often face limitations in terms of efficiency, flexibility, and steady-state error reduction. This manuscript proposes a hybrid technique to optimize steady-state powerflow within Smart Grids (SGs) by combining DC/DC converters with DC/AC inverters. The proposed method combines the gradient boosting decision tree (GBDT) and Honey Badger Algorithm (HBA) commonly known as the GBDT-HBA method. The HBA is used to improve the control parameters of the hybrid converter. The GBDT is used to predict the control parameters. Among the generation source and microgrid (MG) system, the energy flow is assessed with energy routers. The proposed technique shows a higher efficiency of 96%, low steady-state error of 0.513 %, and less THD of 2.52 % compared to other existing Salp Swarm Algorithm (SSA), Ant Lion optimization (ALO), particle swarm optimization (PSO), techniques.
Phase-shifting transformer (PST) is one of the flexible AC transmission technologies to solve the problem of uneven power transmission. Considering that PST can also be used as a regulation means for the economic oper...
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Phase-shifting transformer (PST) is one of the flexible AC transmission technologies to solve the problem of uneven power transmission. Considering that PST can also be used as a regulation means for the economic operation of the system, it is necessary to study the power flow optimization of power systems with PST. In order to find a more efficient power flow optimization method, an improved genetic algorithm including a data-driven module is proposed. This method uses the deep belief network (DBN) to train the sample set of the powerflow and obtains a high-precision proxy model. Then, the calculation of the DBN model replaces the traditional adaptation function calculation link which is very time-consuming due to a great quantity of AC powerflow solution work. In addition, the sectional powerflow reversal elimination mechanism in the genetic algorithm is introduced and appropriately co-designed with DBN to avoid an unreasonable powerflow distribution of the grid section with PST. Finally, by comparing with the traditional model-driven genetic algorithm and traditional mathematical programming method, the feasibility and the validity of the method proposed in this paper are verified on the IEEE 39-node system.
DC distribution grids with distributed energy integration have been gaining a continually increasing interest in recent years both in academia and industry, powerflow of the grids is a key issue to make use of these ...
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DC distribution grids with distributed energy integration have been gaining a continually increasing interest in recent years both in academia and industry, powerflow of the grids is a key issue to make use of these energy effectively and reliably, paper aims at optimizing the powerflow of DC distribution through the upper level control, by considering the factors of distributed energy permeability and DC grid topology, without hardware investment increase nor using complex algorithm. firstly, the change rule of the network loss and voltage distribution are studied under different distributed energy permeability values and DC grid topology, Secondly, one OPF mathematical model of DC distribution network is established taking the index of network loss and voltage imbalance degree as objective function. According to the change of system flow, the optimized instruction value is provided by the system through calculation for each AC/DC, DC/DC converter;an optimization method of DC powerflow is presented by controlling converter instruction. At last, two typical cases are demonstrated by simulation of PSCAD/EMTDC, indexes of the network loss and voltage imbalance degree of the DC distribution network are compared before and after the optimization, Simulation results show that the presented method is feasible to promote DC Distribution Grid.
optimization of powerflow (OPF) is a notable key tool pertinent to power system process, in both setting up and working phases and it is structured for a specific objective to optimize over power system variables, ba...
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With the increasing concerns on the environment and fossil resources, more and more renewable energies and energy storage systems (ESS) are embedded in active distribution networks (ADN). The stochastic nature of rene...
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ISBN:
(纸本)9781728167824
With the increasing concerns on the environment and fossil resources, more and more renewable energies and energy storage systems (ESS) are embedded in active distribution networks (ADN). The stochastic nature of renewable energies brings great challenges to the power system operation. In this context, a double deep Q-learning based method is proposed to optimize the powerflow of ADN considering the randomness of the load demand, wind speed. Experiment results validate that the proposed approach can master the optimal management strategy of ADN under constrains. Comparison results demonstrate that the proposed data-driven method can achieve better results when dealing with the uncertainty environment.
This paper proposes a robust scheme for optimizing the powerflow in a photovoltaic system. The scheme utilizes distributed saddle point dynamics and a decentralized approach to solve the powerflow problem. It conver...
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This paper proposes a robust scheme for optimizing the powerflow in a photovoltaic system. The scheme utilizes distributed saddle point dynamics and a decentralized approach to solve the powerflow problem. It converts the convex optimization problem of the dynamic system control into the asymptotically stable dynamic systems and employs a linear approximation of powerflow equations;speciflcally, a quadratic programming model is deployed with the aim of minimizing real-power losses to guarantee a globally optimal solution. Then, the photovoltaic inverters and electric networks are analyzed independently in a decentralized manner to exchange injection power among nodes while maintaining their independence to support the plug-and-play feature. A case study and the experimental results show that the proposed scheme achieves higher optimization accuracy and are more economical than the existing state-of-the-art schemes.
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