Integration and optimal control of microcsp with building hvac systems: Review and future directions

Heating, ventilation, and air-conditioning (HVAC) systems are omnipresent in modern buildings and are responsible for a considerable share of consumed energy and the electricity bill in buildings. On the other hand, solar energy is abundant and could be used to support the building HVAC system through cogeneration of electricity and heat. Micro-scale concentrated solar power (MicroCSP) is a propitious solution for such applications that can be integrated into the building HVAC system to optimally provide both electricity and heat, on-demand via application of optimal control techniques. The use of thermal energy storage (TES) in MicroCSP adds dispatching capabilities to the MicroCSP energy production that will assist in optimal energy management in buildings. This work presents a review of the existing contributions on the combination of MicroCSP and HVAC systems in buildings and how it compares to other thermal-assisted HVAC applications. Different topologies and architectures for the integration of MicroCSP and building HVAC systems are proposed, and the components of standard MicroCSP systems with their control-oriented models are explained. Furthermore, this paper details the different control strategies to optimally manage the energy flow, both electrical and thermal, from the solar field to the building HVAC system to minimize energy consumption and/or operational cost

Droop control in DQ coordinates for fixed frequency inverter-based AC microgrids

This paper presents a proof-of-concept for a novel dq droop control technique that applies DC droop control methods to fixed frequency inverter-based AC microgrids using the dq0 transformation. Microgrids are usually composed of distributed generation units (DGUs) that are electronically coupled to each other through power converters. An inherent property of inverter-based microgrids is that, unlike microgrids with spinning machines, the frequency of the parallel-connected DGUs is a global variable independent from the output power since the inverters can control the output waveform frequency with a high level of precision. Therefore, conventional droop control methods that distort the system frequency are not suitable for microgrids operating at a fixed frequency. It is shown that the proposed distributed droop control allows accurate sharing of the active and reactive power without altering the microgrid frequency. The simulation and hardware-in-the-loop (HIL) results are presented to demonstrate the efficacy of the proposed droop control. Indeed, following a load change, the dq droop controller was able to share both active and reactive power between the DGUs, whereas maintaining the microgrid frequency deviation at 0% and the bus voltage deviations below 6% of their respective nominal values

Radiofrequency Ablation for Adenomyosis.

Adenomyosis is a common benign gynecologic condition characterized by ectopic endometrial glands and stroma in the myometrium causing pain (dysmenorrhea) and abnormal uterine bleeding. New interventional techniques have been introduced over recent years. This study evaluates the treatment success and side effects of radiofrequency ablation. An electronic literature search in the PubMed, Scopus, and ScienceDirect databases was carried out on the outcomes of pain reduction and, secondarily, on abnormal uterine bleeding, reintervention, reproductive outcome, imaging outcome, and complications. There was a mean decrease in dysmenorrhea pain scores by -63.4 ± 9.0% at 12 months. Data on other outcome parameters were sparse. No major complications were reported. Radiofrequency ablation represents a promising minimally invasive and organ-preserving treatment in patients with symptomatic adenomyosis. It is associated with clinically meaningful improvement of adenomyosis-related pain in the short term

Standardising outcome reporting for clinical trials of interventions for heavy menstrual bleeding: Development of a core outcome set

OBJECTIVE: To develop a core outcome set for heavy menstrual bleeding (HMB). DESIGN: Core outcome set (COS) development methodology described by the COMET initiative. SETTING: University hospital gynaecology department, online international survey and web-based international consensus meetings. POPULATION OR SAMPLE: Phase 1: Systematic review of previously reported outcomes to identify potential core outcomes. Phase 2: Qualitative studies with patients to identify outcomes most important to them. Phase 3: Online two-round Delphi survey to achieve consensus about which outcomes are most important. Phase 4: A consensus meeting to finalise the COS. METHODS: Phase 1: Systematic review of previously reported outcomes to identify potential core outcomes. Phase 2: Qualitative studies with patients to identify outcomes most important to them. Phase 3: Online two-round Delphi survey to achieve consensus about which outcomes are most important. Phase 4: A consensus meeting to finalise the COS. MAIN OUTCOME MEASURES: Outcome importance was assessed in the Delphi survey on a 9-point scale. RESULTS: From the ‘long list’ of 114, 10 outcomes were included in the final COS: subjective blood loss; flooding; menstrual cycle metrics; severity of dysmenorrhoea; number of days with dysmenorrhoea; quality of life; adverse events; patient satisfaction; number of patients going on to have further treatment for HMB and haemoglobin level. CONCLUSIONS: The final COS includes variables that are feasible for use in clinical trials in all resource settings and apply to all known underlying causes of the symptom of HMB. These outcomes should be reported in all future trials of interventions, their systematic reviews, and clinical guidelines to underpin policy

Building-to-grid optimal control of integrated MicroCSP and building HVAC system for optimal demand response services

The world is shifting toward cleaner and more sustainable power generation to face the challenges of climate change. Renewable energy sources such as solar, wind, hydraulic are now the go-to technologies for the new power generation system. However, these sources are highly intermittent and introduce uncertainty to the power grid which affects its frequency and voltage and could jeopardize its stable operations. The integration of micro-scale concentrated solar power (MicroCSP) and thermal energy storage with the heating, ventilation, and air conditioning (HVAC) system gives the building greater leeway to control its loads which can allow it to support the power grid by providing demand response (DR) services. Indeed, the optimal control of the power flowing between the MicroCSP, the HVAC system, and the thermal zones can bring additional degrees of freedom to the building which can be relegated to the power grid based on the objective function and the incentives provided by the latter. This article presents an in-depth investigation of the MicroCSP potential to provide ancillary services to the power grid. It focuses on evaluating the effect of incentives provided by the power grid on the building participation to the load following programs. It also demonstrates how the MicroCSP can help the building deal with constraints related to load peak shaving and ramp-rate reduction set by the power grid as part of long-term DR contracts. A sensitivity analysis is carried out to confront the results to prediction uncertainties of the energy prices and the weather conditions