Durability of traditional reactive powder concrete （RPC） with rich cement and high volume of fly-ash reactive powder concrete （FRPC） were studied. The X-diffraction and scanning electron microscope （SEM） measure...Durability of traditional reactive powder concrete （RPC） with rich cement and high volume of fly-ash reactive powder concrete （FRPC） were studied. The X-diffraction and scanning electron microscope （SEM） measurement was imployed to analyze the microstructure. The results show that both types of RPC have higher compressive strength, less volume shrinkage ratio and better carbonation-, chloride-, freezing-resistances than the conventional concrete. The results of X-diffraction indicate that they basically have C-S-H as the main composition without Ca（OH）2 crystal and ettringite. SEM results show that hydration products of FRPC is mainly Ⅲ-C-S-H which is piled up closely like densely arranged stone body and it has very compacted structure, in addition, Ca/Si ratio of C-S-H gel is lower than 1.5.展开更多
This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power c...This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power channel(FRPC)and a voltage-real power channel(VRPC).For frequency control in the power distribution system with high resistance/inductance ratio,the coupling mechanism between rate of change of frequency(RoCoF)and required reactive power(RRP)of grids is analyzed,indicating RoCoF is proportional to RRP.Thus,RoCoF is utilized in FRPC to generate reactive power for complementary inertial emulating control.Meanwhile,for voltage control,coupling characteristics between rate of change of voltage(RoCoV)and demanding real power(DRP)of grids is also studied,revealing RoCoV is proportional to DRP.Therefore,it can be adopted in VRPC to generate real power for complementary voltage control.Then,grid-voltage-modulated direct power control is selected as the inner power control loop to track power references with faster dynamic performance compared with traditional vector-oriented control.Finally,simulations and hardware-in-loop experiments validate improvement in performance of grid frequency and voltage control based on the proposed method.展开更多
文摘Durability of traditional reactive powder concrete （RPC） with rich cement and high volume of fly-ash reactive powder concrete （FRPC） were studied. The X-diffraction and scanning electron microscope （SEM） measurement was imployed to analyze the microstructure. The results show that both types of RPC have higher compressive strength, less volume shrinkage ratio and better carbonation-, chloride-, freezing-resistances than the conventional concrete. The results of X-diffraction indicate that they basically have C-S-H as the main composition without Ca（OH）2 crystal and ettringite. SEM results show that hydration products of FRPC is mainly Ⅲ-C-S-H which is piled up closely like densely arranged stone body and it has very compacted structure, in addition, Ca/Si ratio of C-S-H gel is lower than 1.5.
基金supported by the National Natural Science Foundation of China under Project U22B20100in part by State Key Laboratory of Power System Operation and Control(SKLD24 KM14)State-funded Postdoctoral Researcher Program(GZC20231212)。
文摘This paper proposes a fast coordinated power control method based on two augmented channels(AC)in battery energy storage system(BESS)to improve inertial and voltage support capability,i.e.,a frequency-reactive power channel(FRPC)and a voltage-real power channel(VRPC).For frequency control in the power distribution system with high resistance/inductance ratio,the coupling mechanism between rate of change of frequency(RoCoF)and required reactive power(RRP)of grids is analyzed,indicating RoCoF is proportional to RRP.Thus,RoCoF is utilized in FRPC to generate reactive power for complementary inertial emulating control.Meanwhile,for voltage control,coupling characteristics between rate of change of voltage(RoCoV)and demanding real power(DRP)of grids is also studied,revealing RoCoV is proportional to DRP.Therefore,it can be adopted in VRPC to generate real power for complementary voltage control.Then,grid-voltage-modulated direct power control is selected as the inner power control loop to track power references with faster dynamic performance compared with traditional vector-oriented control.Finally,simulations and hardware-in-loop experiments validate improvement in performance of grid frequency and voltage control based on the proposed method.
