In the context of constructing new power systems, the intermittency and volatility of high-penetration renewable generation pose new challenges to the stability and secure operation of power systems. Enhancing the ramping capability of power systems has become a crucial measure for addressing these challenges. Therefore, this paper proposes a bi-level peak regulation optimization model for power systems considering ramping capability and demand response, aiming to mitigate the challenges that the uncertainty and volatility of renewable energy generation impose on power system operations. Firstly, the upper-level model focuses on minimizing the ramping demand caused by the uncertainty, taking into account concerned constraints such as the constraint of price-guided demand response, the constraint of satisfaction with electricity usage patterns, and the constraint of cost satisfaction. By solving the upper-level model, the ramping demand of the power system can be reduced. Secondly, the lower-level model aims to minimize the overall cost of the power system, considering constraints such as power balance constraints, power flow constraints, ramping capability constraints of thermal power units, stepwise ramp rate calculation constraints, and constraints of carbon capture units. Based on the ramping demand obtained by solving the upper-level model, the outputs of the generation units are optimized to reduce operation cost of power systems. Finally, the proposed peak regulation optimization model is verified through simulation based on the IEEE 39-bus system. The results indicate that the proposed model, which incorporates ramping capability and demand response, effectively reduces the comprehensive operational cost of the power system.
In airborne MIMO radar, distributing characteristic of clutter have some relation with transmitted waveform diversity and Waveform Synthetic Structure. In this paper , we use the predominance of Transmitted waveform diversity on airborne MIMO radar, A joint transmitter-receiver adaptive dispose algorithm is proposed, and STAP dispose is done in wave, air and time dimension for airborne MIMO radar. The result of simulations show the proposed algorithm achieved the aim of clutter joint suppression, sequentially, which increase the performance of clutter suppression on airborne MIMO radar.
In this study, high spatiotemporal resolution of five latent heat flux (LHF) datasets are compared over the Northwest Pacific Ocean for the period 1998–2007. Overall, the datasets show encouraging agreement in spatial and temporal characteristics. However, there are substantial discrepancies, especially in magnitude, both spatially and temporally. The ERA-Interim dataset gives the maximum LHF while the SeaFlux dataset gives the minimum. These consistencies and discrepancies of the LHF in the five datasets are mainly due to the differences in bulk variables, specifically the sea–air specific humidity difference (Qs-a) and wind speed. Generally, large Qs-a leads to large LHF. However, wind speed and Qs-a play different roles in different regions. The maximum LHF in the Kuroshio western boundary current region arises from high wind coupling with large Qs-a, and the minimum LHF at low latitude is mainly due to weak winds whilst at high latitude it is mainly due to the rapid poleward decrease of Qs-a.
In this paper, a novel method of resolving velocity ambiguity in the pulse Doppler (PD) radar is proposed. By using multi-carrier-frequency waveform and Chinese Remainder Theorem (CRT), this method is able to overcome the velocity ambiguity. Furthermore, a modified algorithm with better robustness is deduced and its performances are analyzed in detail. Specific conclusions are verified with some simulation results.
The operating principles and elements of an exhaust valve were analyzed with the purpose of researching valve's failure.A reliability test-bench was designed to carry out failure-induced test based on the operating characteristics of the valve.The test results indicate that the performance decline of the seal ring is the primary reason of valve's failure.Improved measure was put forward and a new kind of seal ring was designed.The test results validate the creditability and feasibility of this measure.
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