Yechun Xin¹, Xinyuan Zhao¹, Dong Ding², Shuyu Chen², Chuanjie Wang², Tuo Wang^1,*

Energy Engineering, Vol.123, No.1, 2026, DOI:10.32604/ee.2025.069748 - 27 December 2025

Abstract To enhance power flow regulation in scenarios involving large-scale renewable energy transmission via high-voltage direct current (HVDC) links and multi-infeed DC systems in load-center regions, this paper proposes a hybrid modular multilevel converter–capacitor-commutated line-commutated converter (MMC-CLCC) HVDC transmission system and its corresponding control strategy. First, the system topology is constructed, and a submodule configuration method for the MMC—combining full-bridge submodules (FBSMs) and half-bridge submodules (HBSMs)—is proposed to enable direct power flow reversal. Second, a hierarchical control strategy is introduced, including MMC voltage control, CLCC current control, and a coordination mechanism, along with the derivation of… More >

Cuiping Li¹, Jiacheng Sun¹, Qiang Li², Qi Guo², Junhui Li^1,*, Shuo Yu², Jingbo Wang², Wenze Li²

Energy Engineering, Vol.122, No.8, pp. 3055-3077, 2025, DOI:10.32604/ee.2025.064440 - 24 July 2025

Abstract The penetration rate of new wind and photovoltaic energy in the power system has increased significantly, and the dramatic fluctuation of the net load of the grid has led to a severe lack of flexibility in the regional grid. This paper proposes a hierarchical optimal dispatch strategy for a high proportion of new energy power systems that considers the balanced response of grid flexibility. Firstly, various flexibility resource regulation capabilities on the source-load side are analyzed, and then flexibility demand and flexibility response are matched, and flexibility demand response assessment is proposed; then, a hierarchical… More >

Jiaqing Wang¹, Yuming Shen^2,*, Xuli Wang², Jiayin Xu²

Energy Engineering, Vol.122, No.7, pp. 2751-2766, 2025, DOI:10.32604/ee.2025.064317 - 27 June 2025

Abstract To adapt to the uncertainty of new energy, increase new energy consumption, and reduce carbon emissions, a high-voltage distribution network energy storage planning model based on robustness-oriented planning and distributed new energy consumption is proposed. Firstly, the spatio-temporal correlation of large-scale wind-photovoltaic energy is modeled based on the Vine Copula model, and the spatial correlation of the generated wind-photovoltaic power generation is corrected to get the spatio-temporal correlation of wind-photovoltaic power generation scenarios. Finally, considering the subsequent development of new energy on demand for high-voltage distribution network peaking margin and the economy of the system More >

Chenxu Wang^*, Jing Bian, Rui Yuan

Energy Engineering, Vol.122, No.3, pp. 985-1003, 2025, DOI:10.32604/ee.2025.059559 - 07 March 2025

Abstract Considering the uncertainty of grid connection of electric vehicle charging stations and the uncertainty of new energy and residential electricity load, a spatio-temporal decoupling strategy of dynamic reactive power optimization based on clustering-local relaxation-correction is proposed. Firstly, the k-medoids clustering algorithm is used to divide the reduced power scene into periods. Then, the discrete variables and continuous variables are optimized in the same period of time. Finally, the number of input groups of parallel capacitor banks (CB) in multiple periods is fixed, and then the secondary static reactive power optimization correction is carried out by… More >

Yuanxiang Luo^*, Linshu Cai, Nan Zhang

Energy Engineering, Vol.122, No.2, pp. 765-783, 2025, DOI:10.32604/ee.2024.058426 - 31 January 2025

Abstract Large-scale new energy grid connection leads to the weakening of the system frequency regulation capability, and the system frequency stability is facing unprecedented challenges. In order to solve rapid frequency fluctuation caused by new energy units, this paper proposes a new energy power system frequency regulation strategy with multiple units including the doubly-fed pumped storage unit (DFPSU). Firstly, based on the model predictive control (MPC) theory, the state space equations are established by considering the operating characteristics of the units and the dynamic behavior of the system; secondly, the proportional-differential control link is introduced to… More > Graphic Abstract

Xiuyun Wang, Zipeng Zhang, Chuang Liu^*, Guoliang Bian

Energy Engineering, Vol.122, No.2, pp. 577-619, 2025, DOI:10.32604/ee.2024.056748 - 31 January 2025

Abstract As the power system transitions to a new green and low-carbon paradigm, the penetration of renewable energy in China’s power system is gradually increasing. However, the variability and uncertainty of renewable energy output limit its profitability in the electricity market and hinder its market-based integration. This paper first constructs a wind-solar-thermal multi-energy complementary system, analyzes its external game relationships, and develops a bi-level market optimization model. Then, it considers the contribution levels of internal participants to establish a comprehensive internal distribution evaluation index system. Finally, simulation studies using the IEEE 30-bus system demonstrate that the More >

Yun Zhang^1,*, Zifen Han², Biao Tian¹, Ning Chen², Yi Fan³

Energy Engineering, Vol.122, No.1, pp. 167-184, 2025, DOI:10.32604/ee.2024.056190 - 27 December 2024

Abstract The new energy power generation is becoming increasingly important in the power system. Such as photovoltaic power generation has become a research hotspot, however, due to the characteristics of light radiation changes, photovoltaic power generation is unstable and random, resulting in a low utilization rate and directly affecting the stability of the power grid. To solve this problem, this paper proposes a coordinated control strategy for a new energy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit. Firstly, the variational mode decomposition algorithm is… More >

Xiaohui Ye^1,*, Fucheng Tan¹, Xinli Song², Hanyang Dai², Xia Li², Shixia Mu², Shaohang Hao²

Energy Engineering, Vol.121, No.12, pp. 3689-3710, 2024, DOI:10.32604/ee.2024.055200 - 22 November 2024

Abstract Energy storage batteries can smooth the volatility of renewable energy sources. The operating conditions during power grid integration of renewable energy can affect the performance and failure risk of battery energy storage system (BESS). However, the current modeling of grid-connected BESS is overly simplistic, typically only considering state of charge (SOC) and power constraints. Detailed lithium (Li)-ion battery cell models are computationally intensive and impractical for real-time applications and may not be suitable for power grid operating conditions. Additionally, there is a lack of real-time batteries risk assessment frameworks. To address these issues, in this… More >

Tiezhou Wu, Yukan Zhang^*

Energy Engineering, Vol.121, No.8, pp. 2231-2255, 2024, DOI:10.32604/ee.2024.049883 - 19 July 2024

Abstract In order to solve the problem of inconsistent energy in the charging and discharging cycles of lithium-ion battery packs, a new multilayer equilibrium topology is designed in this paper. The structure adopts a hierarchical structure design, which includes intra-group equilibrium, primary inter-group equilibrium and secondary inter-group equilibrium. This structure greatly increases the number of equilibrium paths for lithium-ion batteries, thus shortening the time required for equilibrium, and improving the overall efficiency. In terms of control strategy, fuzzy logic control (FLC) is chosen to control the size of the equilibrium current during the equilibrium process. We… More >

Shichao Cao^*, Yonggang Dong, Xiaoying Liu

Energy Engineering, Vol.121, No.4, pp. 1109-1125, 2024, DOI:10.32604/ee.2023.043004 - 26 March 2024

Abstract The synchronous virtual machine uses inverter power to imitate the performance of the conventional synchronous machine. It also has the same inertia, damping, frequency, voltage regulation, and other external performance as the generator. It is the key technology to realize new energy grid connections’ stable and reliable operation. This project studies a dynamic simulation model of an extensive new energy power system based on the virtual synchronous motor. A new energy storage method is proposed. The mathematical energy storage model is established by combining the fixed rotor model of a synchronous virtual machine with the… More >