A coordinated control method of voltage and reactive power for active distribution net-works based on soft open point

The increasing penetration of distributed generators (DGs) exacerbates the risk of voltage violations in active distribu-tion networks (ADNs). The conventional voltage regulation de-vices limited by the physical constraints are difficult to meet the requirement of real-time voltage and VAR control (VVC) with high precision when DGs fluctuate frequently. However, soft open point (SOP), a flexible power electronic device, can be used as the continuous reactive power source to realize the fast voltage regu-lation. Considering the cooperation of SOP and multiple regula-tion devices, this paper proposes a coordinated VVC method based on SOP for ADNs. Firstly, a time-series model of coordi-nated VVC is developed to minimize operation costs and eliminate voltage violations of ADNs. Then, by applying the linearization and conic relaxation, the original nonconvex mixed-integer non-linear optimization model is converted into a mixed-integer sec-ond-order cone programming (MISOCP) model which can be efficiently solved to meet the requirement of voltage regulation rapidity. Case studies are carried out on the IEEE 33-node system and IEEE 123-node system to illustrate the effectiveness of the proposed method

Effect of coffee consumption on thyroid function: NHANES 2007-2012 and Mendelian randomization

BackgroundCoffee is one of the most consumed beverages worldwide, but the effects on the thyroid are unknown. This study aims to examine the association between coffee and thyroid function.MethodsParticipant data (≥ 20 years, n = 6578) for the observational study were obtained from NHANES 2007-2012. Analysis was performed using weighted linear regression models and multiple logistic regression models. Genetic datasets for Hyperthyroidism and Hypothyroidism were obtained from the IEU database and contained 462,933 European samples. Mendelian randomization (MR) was used for the analysis, inverse variance weighting (IVW) was the main method of analysis.ResultsIn the model adjusted for other covariates, participants who drank 2-4 cups of coffee per day had significantly lower TSH concentrations compared to non-coffee drinkers (b=-0.23, 95% CI: -0.30, -0.16), but no statistically significant changes in TT4, FT4, TT3 and FT3. In addition, participants who drank <2 cups of coffee per day showed a low risk of developing subclinical hypothyroidism. (OR=0.60, 95% CI: 0.41, 0.88) Observational studies and MR studies have demonstrated both that coffee consumption has no effect on the risk of hyperthyroidism and hypothyroidism.ConclusionsOur study showed that drinking <2 cups of coffee per day reduced the risk of subclinical hypothyroidism and drinking 2-4 cups of coffee reduced serum TSH concentrations. In addition, coffee consumption was not associated with the risk of hyperthyroidism and hypothyroidism

The Valve Timing Optimization of the Diesel Engine Based on Response Surface Methodology

To study the effect of valve timing on the diesel engine performance, the simulation model of diesel engine was established with AVL BOOST and its accuracy was proved. The volumetric efficiency is one of the important indicators to evaluate engine performance. The volumetric efficiency as optimization objective and valve timing were optimized and discussed by using Box-Behnken test method and the response surface methodology. Optimization result shows that volumetric efficiency of the diesel engine can been increased by 6.42% under rated speed

Research of the Vehicle Load Control System Integration Device

With the gradual development of economy, the scale of transportation industry continues to expand. The problem of overload or overrun in the vehicle transport has emerged. Therefore, how simply and conveniently to know the vehicle load and how to effectively limit overload has become a key issue. This paper demonstrates the feasibility of vehicle load control system from the above problems. Through the pressure sensors installed in the vehicle suspension, the single-chip microprocessor receives the information transmitted by the pressure sensors, and calculates the total weight of the vehicle load; if overweight, the single-chip microprocessor will send commands to the ignition system, to stop the ignition system working. Its purpose is to improve vehicle safety and effectively reduce heavy workload of the vehicle detection station to improve their work efficiency

Sestrin2 promotes LKB1‐mediated AMPK activation in the ischemic heart

The regulation of AMPK in the ischemic heart remains incompletely understood. Recent evidence implicates the role of Sestrin2 in the AMPK signaling pathway, and it is hypothesized that Sestrin2 plays an influential role during myocardial ischemia to promote AMPK activation. Sestrin2 protein was found to be expressed in adult cardiomyocytes and accumulated in the heart during ischemic conditions. Sestrin2 knockout (KO) mice were used to determine the importance of Sestrin2 during ischemia and reperfusion (I/R) injury. When wild‐type (WT) and Sestrin2 KO mice were subjected to in vivo I/R, myocardial infarct size was significantly greater in Sestrin2 KO compared with WT hearts. Similarly, Langendorff perfused hearts indicated exacerbated postischemic contractile function in Sestrin2 KO hearts compared with WT. Ischemic AMPK activation was found to be impaired in the Sestrin2 KO hearts. Immunoprecipitation of Sestrin2 demonstrated an association with AMPK. Moreover, liver kinase B1 (LKB1), a major AMPK upstream kinase, was associated with the Sestrin2‐AMPK complex in a time‐dependent manner during ischemia, whereas this interaction was nearly abolished in Sestrin2 KO hearts. Thus, Sestrin2 plays an important role in cardioprotection against I/R injury, serving as an LKB1‐AMPK scaffold to initiate AMPK activation during ischemic insults.—Morrison, A., Chen, L. Wang, J., Zhang, M., Yang, H., Ma, Y., Budanov, A., Lee, J. H., Karin, M., Li, J. Sestrin2 promotes LKB1‐mediated AMPK activation in the ischemic heart. FASEB J. 29, 408‐417 (2015). www.fasebj.orgPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154534/1/fsb2fj14258814-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154534/2/fsb2fj14258814.pd

Multi-stage expansion planning of energy storage integrated soft open points considering tie-line reconstruction

With the rapid development of flexible interconnection technology in active distribution networks (ADNs), many power electronic devices have been employed to improve system operational performance. As a novel fully-controlled power electronic device, energy storage integrated soft open point (ESOP) is gradually replacing traditional switches. This can significantly enhance the controllability of ADNs. To facilitate the utilization of ESOP, device locations and capacities should be configured optimally. Thus, this paper proposes a multi-stage expansion planning method of ESOP with the consideration of tie-line reconstruction. First, based on multi-terminal modular design characteristics, the ESOP planning model is established. A multi-stage planning framework of ESOP is then presented, in which the evolutionary relationship among different planning schemes is analyzed. Based on this framework, a multi-stage planning method of ESOP with consideration of tie-line reconstruction is subsequently proposed. Finally, case studies are conducted on a modified practical distribution network, and the cost–benefit analysis of device and multiple impact factors are given to prove the effectiveness of the proposed method

Operational flexibility of active distribution networks: definition, quantified calculation and application

With a high penetration of intermittent distributed generators (DGs), the uncertainties in active distribution networks (ADNs) are exacerbated and further coupled in the networks. It brings enormous challenges on system operation and puts forward a higher requirement for the operational flexibility of ADNs. However, due to the secure constraints and diverse operational requirements, the controllability of controllable resources (CRs) cannot fully facilitate the flexible operation of ADNs. Operational flexibility is seen as a link between diverse operational requirements and flexible adjustment capabilities of CRs, which also represents the ability of the network to deploy its CRs to respond to the change of operation states. Under the framework of operational flexibility, multiple types of operational optimization problems can be reinterpreted, which provides a new perspective for the operation of ADNs. In this paper, the definition and region-based mathematical formulation of operational flexibility for ADNs are proposed firstly. Then the quantified calculation method of operational flexibility is proposed to represent flexibility provision (FP) and flexibility availability (FA). The application of operational flexibility is analyzed from the perspective of diverse operation and improvement of flexibility. Finally, case studies are performed on the modified IEEE 33-node system to show the effectiveness of the proposed method