Large-scale grid-connection of wind power has a profound impact on the characteristics of power grids. To study the mechanism of the influence of voltage sudden changes on the transient response characteristics of dou...
Large-scale grid-connection of wind power has a profound impact on the characteristics of power grids. To study the mechanism of the influence of voltage sudden changes on the transient response characteristics of double-fed wind fields is the basis of ensuring the safe and stable operation of power grids. In this paper, the expression of rotor current under symmetrical voltage sudden changes is derived, and the related factors affecting the transient response characteristics of rotor current are analyzed. Then, a detailed DFIG model is built in PSCAD, and a variety of scenarios are simulated to verify the accuracy of the proposed doubly-fed fan’s transient response characteristics under symmetrical voltage sudden changes.
The protection link within the wind farm is the key link that affects the transient characteristics of the wind farm, and also has the greatest impact on the complexity of scene construction. Therefore, it is urgent t...
The protection link within the wind farm is the key link that affects the transient characteristics of the wind farm, and also has the greatest impact on the complexity of scene construction. Therefore, it is urgent to study the method that can quickly build the chopper circuit and crowbar circuit action scene during the evaluation of the equivalent model of the wind farm. In this paper, a fast generation method of wind farm protectionstate scenarios based on Deep Belief Network (DBN) is proposed. Firstly, characteristic quantities that affect the protection action of a single fan in a wind farm are extracted, such as terminal voltage drop (the junction voltage of a single fan is equal to the terminal voltage), wind speed, etc. Simulation is carried out on a single fan in scenarios with different characteristic quantities, and records of characteristic quantities and protection actions are put into the DBN model for training as a sample set. Through training, a DBN model which can directly and accurately generate the fan protectionstate according to the characteristic quantity is obtained. Then, the topological structure and line impedance information of the wind farm are obtained, and the relationship between the voltage drop at the junction point and the voltage drop at the end of each fan in the wind farm is obtained. Combined with the voltage drop at the end of each fan in the wind farm and the deep belief network model, the fan protection action scene in the wind farm can be quickly generated for equivalent model evaluation. Finally, a numerical example is given to verify the effectiveness of the proposed method.
An accurate wind farm model is a crucial prerequisite to ensure that the simulation results of the power system containing wind power align with reality. Hence, it is imperative to establish a system for evaluating th...
An accurate wind farm model is a crucial prerequisite to ensure that the simulation results of the power system containing wind power align with reality. Hence, it is imperative to establish a system for evaluating the accuracy of wind farm models. This paper examines the fault response characteristics of wind turbines and proposes a multi-dimensional quantitative index system for assessing the equivalency of wind farm models. The entire process can be segmented into two stages: the transient period immediately following the fault occurrence and the subsequent steady-state phase. The evaluation indexes for assessing the accuracy of wind farm models are voltage dynamic response, active power dynamic response, and reactive power dynamic response. These indexes are formulated to evaluate the equivalency of wind farm models across various stages.
The power system restoration control has a higher uncertainty level than the preventive control of cascading failures. In order to ensure the feasibility of the decision support system of restoration control, a decisi...
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The power system restoration control has a higher uncertainty level than the preventive control of cascading failures. In order to ensure the feasibility of the decision support system of restoration control, a decision support framework for adaptive restoration control of transmission system is proposed, which can support the coordinated restoration of multiple partitions, coordinated restoration of units and loads, and coordination of multi-partition decision-making process and actual restoration process. The proposed framework is divided into two layers, global coordination layer and partition optimization layer. The upper layer partitions the transmission system according to the power outage scenario, constantly and dynamically adjusts the partitions during the restoration process, and optimizes the time-space decision-making of inter-partition connectivity. For each partition, the lower layer pre-selects restoration targets according to the estimated restoration income, optimizes the corresponding restoration paths, and evaluates the restoration plans according to the expected net income per unit of power consumption. During the restoration process, if the restoration operation such as energizing the outage branch fails, the current restoration plan will be adaptively switched to the sub-optimal one or re-optimized if necessary. The framework includes two operation modes, i.e., the on-line operation mode and training simulation mode, and provides an information interaction interface for collaborative restoration with related distribution systems. The effectiveness and adaptability of the proposed framework is demonstrated by simulations using the modified IEEE 118-bus system.
With large scale new energy power being connected to the grid, the frequency support capability of the system decreases gradually. In order to meet the regulation requirements of system frequency stability and lay the...
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ISBN:
(数字)9798350363951
ISBN:
(纸本)9798350363968
With large scale new energy power being connected to the grid, the frequency support capability of the system decreases gradually. In order to meet the regulation requirements of system frequency stability and lay the foundation for frequency stability coordination and optimization control, it is necessary to use reasonable quantitative evaluation indicators for primary frequency regulation performance. Firstly, the dynamic response characteristics of frequency modulation resources in load fluctuation scenarios and large power disturbance scenarios are analyzed separately. Then, by mastering the frequency response characteristics of the system considering primary frequency regulation in different scenarios, the key factors affecting the safety and stability characteristics of the system frequency are determined. Finally, a quantitative evaluation method for the primary frequency regulation performance of frequency modulation resources is proposed, and the applicability of the proposed evaluation method is verified based on typical scenario examples.
This paper presents a method of applying MMC based on battery energy storage system (BESS) to HVDC system to realize power decoupling control on AC and DC side. Firstly, the basic structure and working principle of MM...
This paper presents a method of applying MMC based on battery energy storage system (BESS) to HVDC system to realize power decoupling control on AC and DC side. Firstly, the basic structure and working principle of MMC-HVDC system based on BESS are analyzed. Then, based on the mathematical equivalent model, the MMC-BESS decoupling control method based on DC power control is derived, and the AC-DC power decoupling control is realized. Finally, a +400kV MMC-HVDC system is built on the RTDS platform, and the proposed control strategy and power decoupling effect are verified. The results show that the MMC-BESS control strategy proposed in this paper is effective. The MMC-HVDC system based on BESS can realize active power decoupling control between AC side and DC side, and the unbalanced power between AC side and DC side can be compensated by the charge and discharge of BESS.
The anomaly detection for substation equipment is of great significance to maintain the safe operation of substations. With the development of deep learning, many anomaly detection methods based on deep convolutional ...
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The constant droop coefficient (DC) in the traditional f-P and V-Q droop control is not conducive to the state-of-charge (SoC) management of the battery energy storage (BES) system. This paper proposes an improved dro...
The constant droop coefficient (DC) in the traditional f-P and V-Q droop control is not conducive to the state-of-charge (SoC) management of the battery energy storage (BES) system. This paper proposes an improved droop control strategy (DCS) for the power grid which considers both the power frequency adjustment of the power system and the SoC management constraints of the BES. The proposed improved DCS is enabled to adjust the DC according to the SoC status of the BES. Case studies verify the effectiveness of the proposed DCS, which significantly reduces the frequency change deviation in the dynamic process of the weak power grid.
The high proportion of new energy connected to multi-infeed direct current power system may cause large-scale new energy to enter low voltage ride-through and multiple DC commutation failures under severe grounding fa...
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ISBN:
(数字)9798350363951
ISBN:
(纸本)9798350363968
The high proportion of new energy connected to multi-infeed direct current power system may cause large-scale new energy to enter low voltage ride-through and multiple DC commutation failures under severe grounding faults, and the interactive coupling effect may affect the subsequent recovery process. In response to this phenomenon, interactive indicators are proposed to evaluate the risk of simultaneous faults between DC and new energy during grounding faults, as well as coupling indicators to evaluate the risk of secondary faults during the recovery process of DC and new energy after grounding faults are cleared. Simulation analysis based on actual power grids shows that this indicator can evaluate the interactive coupling process between new energy low voltage ride-through and DC commutation failure intuitively.
In view of the particularity of Chinese word segmentation in the professional field of power grid regulation,the performance of Chinese word segmentation based on traditional statistical algorithm is frequently limite...
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In view of the particularity of Chinese word segmentation in the professional field of power grid regulation,the performance of Chinese word segmentation based on traditional statistical algorithm is frequently limited by the corpus training in the proprietary field,and the insufficient ability of Chinese word segmentation based on dictionary algorithm in identifying new words and disambiguation in the proprietary *** paper proposes a Chinese word segmentation method based on the combination of dictionary and statistical method,and applies it to the application scenario of querying the operation status of power *** method constructs a professional dictionary in the field of power grid regulation by using the Double-Array Tree storage *** using the CRF(Conditional Random Fields)train the text data to generate the model file,and the FMM(Forward Maximum Matching) method is used for Chinese word segmentation combined with the professional dictionary in the field of power grid regulation.A fast and accurate online word segmentation method in the field of power grid regulation is designed and implemented,it performs well in some main performance *** the application scenario of querying the power grid operation status,the Chinese word segmentation results obtained by this method combined with the standard query sentence pattern realize the rapid classification of application scenario query and the accurate execution of operation commands,greatly improve the efficiency and accuracy of querying the power grid operation status,and improve the human-computer interaction experience.
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