[Objectives]This study was conducted to explore the feasibility of planting pepino(Solanum muricatum Ait.)in Qinghai Province,and to understand the cultivation quality and yield in various areas of Qinghai.[Methods]Wi...[Objectives]This study was conducted to explore the feasibility of planting pepino(Solanum muricatum Ait.)in Qinghai Province,and to understand the cultivation quality and yield in various areas of Qinghai.[Methods]With small fruit type of pepino as the material,four areas in eastern Qinghai were selected to determine the agronomic traits,yield and quality indexes of pepino.[Results]Under the same cultivation conditions,there were some differences in the cultivation status of pepino,but overall,pepino fruit had higher quality.Various physiological indexes were correlated with quality and yield.[Conclusions]This study clarified the specific cultivation situation of pepino in Qinghai Province,and evaluated the quality and yield of pepino,providing strong data support for the promotion and planting of pepino in various regions in the future.展开更多
To ensure frequency stability in power systems with high wind penetration,the doubly-fed induction generator(DFIG)is often used with the frequency fast response control(FFRC)to participate in frequency response.Howeve...To ensure frequency stability in power systems with high wind penetration,the doubly-fed induction generator(DFIG)is often used with the frequency fast response control(FFRC)to participate in frequency response.However,a certain output power suppression amount(OPSA)is generated during frequency support,resulting in the frequency modulation(FM)capability of DFIG not being fully utilised,and the system’s unbalanced power will be increased during speed recovery,resulting in a second frequency drop(SFD)in the system.Firstly,the frequency response characteristics of the power system with DFIG containing FFRC are analysed.Then,based on the analysis of the generation mechanism of OPSA and SFD,a combined wind-storage FM control strategy is proposed to improve the system’s frequency response characteristics.This strategy reduces the effect of OPSA and improves the FM capability of DFIG by designing the fuzzy logic of the coefficients of FFRC according to the system frequency index in the frequency support stage.During the speed recovery stage,the energy storage(ES)active power reference value is calculated according to the change of DFIG rotor speed,and the ES output power is dynamically adjusted to reduce the SFD.Finally,taking the IEEE 39-bus test system as an example,real-time digital simulation verification was conducted based on the RTLAB OP5707 simulation platform.The simulation results showthat theproposedmethodcan improve theFMcapabilityofDFIG,reduce the SFDunder thepremise of guaranteeing the rapid rotor speed recovery,and avoid the overshooting phenomenon so that the systemfrequency can be quickly restored to a stable state.展开更多
基金Supported by Science and Technology Demonstration of Rural Revitalization in Jianzha County(2023-NK-X01)。
文摘[Objectives]This study was conducted to explore the feasibility of planting pepino(Solanum muricatum Ait.)in Qinghai Province,and to understand the cultivation quality and yield in various areas of Qinghai.[Methods]With small fruit type of pepino as the material,four areas in eastern Qinghai were selected to determine the agronomic traits,yield and quality indexes of pepino.[Results]Under the same cultivation conditions,there were some differences in the cultivation status of pepino,but overall,pepino fruit had higher quality.Various physiological indexes were correlated with quality and yield.[Conclusions]This study clarified the specific cultivation situation of pepino in Qinghai Province,and evaluated the quality and yield of pepino,providing strong data support for the promotion and planting of pepino in various regions in the future.
基金funded by Jilin Province Science and Technology Development Plan Projects(20230508157RC)the National Natural Science Foundation of China(U2066208).
文摘To ensure frequency stability in power systems with high wind penetration,the doubly-fed induction generator(DFIG)is often used with the frequency fast response control(FFRC)to participate in frequency response.However,a certain output power suppression amount(OPSA)is generated during frequency support,resulting in the frequency modulation(FM)capability of DFIG not being fully utilised,and the system’s unbalanced power will be increased during speed recovery,resulting in a second frequency drop(SFD)in the system.Firstly,the frequency response characteristics of the power system with DFIG containing FFRC are analysed.Then,based on the analysis of the generation mechanism of OPSA and SFD,a combined wind-storage FM control strategy is proposed to improve the system’s frequency response characteristics.This strategy reduces the effect of OPSA and improves the FM capability of DFIG by designing the fuzzy logic of the coefficients of FFRC according to the system frequency index in the frequency support stage.During the speed recovery stage,the energy storage(ES)active power reference value is calculated according to the change of DFIG rotor speed,and the ES output power is dynamically adjusted to reduce the SFD.Finally,taking the IEEE 39-bus test system as an example,real-time digital simulation verification was conducted based on the RTLAB OP5707 simulation platform.The simulation results showthat theproposedmethodcan improve theFMcapabilityofDFIG,reduce the SFDunder thepremise of guaranteeing the rapid rotor speed recovery,and avoid the overshooting phenomenon so that the systemfrequency can be quickly restored to a stable state.