Value of demand flexibility for providing ancillary services: A case for social housing in the Irish DS3 market

This paper evaluates the potential of consumer flexibility from a portfolio of heat loads, solar panels and batteries in Social Housing to provide ancillary services. We propose two new ancillary service products: Turn-Up-Demand (TUD) and Turn-Down-Demand (TDD). We ran simulations for a complete year. The buffer-tank scenario provided earnings of £146/year for an average consumer. Finally, we propose a new policy called the Vulnerable Consumer Priority in Administering System Services (VCPASS) and the use of Heat-as-a-Service (HaaS) to fund the replacement of oil-boilers with heat pumps in fuel poor homes with a rate of 9.99p/kWh of heat for a payback period of 15 years.     

Improvement of customer baselines for the evaluation of demand response through the use of physically-based load models

Demand Response (DR) is an opportunity and a concern for markets as well as power system flexibility. The deployment of DR depends on both knowledge on its performance and how to measure it effectively to provide adequate economic feedback. DR verification requires a baseline reference. This paper introduces a new baseline that provides an evaluation of response based on simple adjustment factors through physically-based models, tools which are also used in DR. The approach includes the detection of licit and gaming responses before and after DR. Results show that errors decrease by 10–15% with respect to conventional approaches.     

Evaluation of commercial building demand response potential using optimal short-term curtailment of heating,ventilation, and air-conditioning loads

Mismatches in power supply and demand due to infrastructure design and commercial development result in negative economic impacts and societal disruption. These impacts are exacerbated by unusually hot weather as well as energy infrastructure failures. Demand reductions by large commercial and industrial customers are increasingly sought by electrical utilities as a means to control severe supply–demand mismatches. Large electricity consumers have used thermal storage systems, on-site electricity generation, shifting of production processes, and short-term curtailment as means to manage and control their demand during peak demand times. Utility notification may be sent to request a reduction of load for a given duration when demand reaches a specified percent of available supply. This paper examines the interconnected nature of the building heating, ventilation, and air-conditioning systems as they apply to short-term demand response (DR) by conducting a reference case investigation into optimal control of building cooling systems for DR.     

冰蓄冷系统的优化控制分析

分析了冰蓄冷系统的冷机优先，蓄冰罐优先和优化控制三种控制策略，提出了优化控制的目标和约束，并以某建筑为例对比分析冰蓄冷系统在优化控制策略和冷机优先控制策略下的运行费，阐明优化控制可以发挥现有系统力，更有效地削减电负荷高峰。     

机房专用恒温恒湿空调机组的优化设计

根据笔者的研发经验,结合制冷、供热、流体力学等基本原理,详细论述了机房空调制冷气流和控制系统关键部件的优化设计方案.     

Interactive Time-of-use demand response for industrial electricity customers: A case study

Demand response (DR) programs are regarded as one of the most reliable and reasonable methods to benefit electricity suppliers and consumers. This paper presents a modified approach to DR based on an Interactive Time-of-Use (ITOU) model by which volunteer industrial customers and their electricity suppliers obtain the best possible performance. Owing to this aim, when studying the region's electrical load profile to determine the peak-hours, the one-year production and sales profile of industrial customers is also studied to select off-peak hours for industrial subscribers. The results of program implementation for the selected and volunteer industrial customers at the sub-transmission level are presented to evaluate the performance of the proposed model. Considering the electricity bills of the subscribers in the program based on reduced energy consumption at peak hours (selected by the utility), and increased energy consumption at the off-peak price (selected by industrial customers), the economic benefits to industrial customers are calculated and verified. Plotting new load curves confirms load shifting from the peak to the valley of the load curve. The obtained results of the conventional TOU and ITOU models indicate that the proposed ITOU is more effective in achieving program goals.     

地铁车站利用需求控制通风技术的可行性研究

介绍了适用于屏蔽门地铁站台的需求控制通风系统。利用动态仿真系统建模,以广州某屏蔽门地铁站台为研究对象,进行了全年能耗计算。结果表明,需求控制通风系统比定风量系统节能30%,比VAV系统节能8%。     

Optimal control of a single-basin tidal power scheme in various operating modes

Operation of a tidal power scheme in ebb generation and double generation modes with or without pumping is described. Dynamic programming is used to formulate the control of the scheme to maximize its energy output when operated in any of these modes: in the formulation hydrodynamic effects within the scheme are neglected but real turbine characteristics are used. Optimal control was found to be unnecessary for ebb generation, but it is essential if the scheme is to be operated in any other mode.     

优化设计与公路工程建设项目的投资控制

介绍了公路优化设计与建设项目投资控制的关系,提出了设计阶段优化设计的建议,有利于搞好公路工程建设项目的投资控制,并且指出设计人员要用价值工程的原理来进行设计方案分析,从而真正达到优化设计。     

A demand limiting strategy for maximizing monthly cost savings of commercial buildings

Monthly peak demand costs usually contribute greatly to the monthly electricity bills of commercial buildings. Peak demand limiting control, which gained substantial attention recently, is an efficient way to reduce it. Most of previous studies either focus on the daily peak demand reduction without taking account the related energy rise, or explore the relationship between energy rise and demand reduction only on a daily basis. Unlike the previous studies, a new demand limiting control strategy is proposed in this paper in order to maximize the monthly cost saving. The new strategy is realized as follows. At first step, a proper monthly demand threshold is identified. At second step, a specific approach, named as proportional-integral-derivative (PID) algorithm, is implemented to restrain the daily peak demand to the given threshold by adjusting the indoor room temperature set-point. The extended pre-cooling duration is also estimated at this step based on the difference between the predicted daily peak demand and the identified threshold. The results of case studies show that the proposed strategy can substantially reduce the monthly electricity cost.     

Optimal control of structures under earthquake excitation based on the colonial competitive algorithm

The active control of engineering structures is one of the best methods to reduce structural responses under seismic excitation for the best performance of structures. This study presents an effective approach for the optimal control of structures under strong ground motion using the colonial competitive algorithm. The colonial competitive algorithm was developed over the last few years in an attempt to overcome the inherent limitations of traditional optimize method. The colonial competitive algorithm has been applied due to its ideal performance in optimal control problem. The effectiveness and performance of the proposed method have been investigated through two numerical examples for the response control of earthquake‐excited structures. The obtained results have been compared with the Linear Quadratic Regulator (LQR) control algorithm, and the performance of the proposed control approach has been found to be better than the LQR controller. Copyright © 2012 John Wiley & Sons, Ltd.     

Optimal control strategies for multi-chiller system based on probability density distribution of cooling load ratio

Probability density distribution profile of cooling load ratio is obtained by Parzen window density estimation method, which is used to describe the building cooling load variation. Based on the analysis of this profile, the optimal sequence control strategies (AI, AII and AIII) are presented. In order to optimize the COP of total chillers, the optimal load allocation control strategy B is presented. The optimal load allocation control strategy BI is presented to improve the strategy B for simplifying the process of the optimal calculation and maintaining stability of the system operating. Simulation results show that these optimal control strategies presented can save more power consumption of chillers operating than the original sequence control strategy. Comparing the strategy B, the strategy BI can avoid unnecessary switch on/off actions of chillers and decrease computational costs.     

高层建筑结构随机振动的最优阻尼器控制策略

提出考虑阻尼器布置与阻尼器参数同步优化的高层建筑结构随机最优控制方法。为有效地寻找每个序列工况的阻尼器最优拓扑和阻尼器最优参数,分别定义了基于超越概率的层可控指标梯度最小准则和能量均衡最优准则。上述控制准则内蕴了系统安全性、系统服务性、系统舒适性、阻尼器工作性以及它们之间的均衡。以随机地震动作用下十层剪切型框架结构的黏滞阻尼器最优控制为例进行分析,结果表明,采用该方法可以以最小的投资获得最大的控制效益,受控后结构反应沿层分布较受控前更均匀、能达到所期望的结构性态。     

考虑控制器拓扑的随机动力系统最优控制

在简要回顾几类结构控制模式的基础上,本文提出考虑控制装置最优布设与控制器参数优化的随机最优控制方法,将它们统一为物理随机最优控制的广义最优控制律。为有效地寻找每个序列工况的控制器最优拓扑和控制器参数,分别定义基于超越概率的层可控指标梯度最小准则和能量均衡最优准则。数值算例分析表明,采用广义最优控制律可以以最小的投资获得最大的控制效益。同时表明,按层可控指标梯度最小准则寻优,比先前按层可控指标最大准则寻优能更有效地收敛到目标性态。     

Optimal microgrid programming based on an energy storage system,price-based demand response,and distributed renewable energy resources

Microgrids (MGs) in distribution systems can be operated in far regions at lower investment costs using renewable distributed energy resources (DERs). The present paper introduces a stochastic model for optimal energy-heat programming and the daily storage of an MG. Bi-level stochastic programming is presented for integrated energy-heat scheduling and storage in the presence of an energy storage system (ESS) and demand response (DR) based on social welfare maximization. Out of the incentive-based DR programs, the tender and redemption and the ancillary services market programs were selected and applied to the given model. Besides, the time of use (TOU) -based DR and real-time pricing (RTP) were considered as the price-based demand response (PBDR) programs in optimal programming. The PBDR programs have been included in the objective function using a linear function based on consumer benefits. The proposed bi-level stochastic model was solved using a developed metaheuristic optimization algorithm called the lightning search algorithm (LSA) in the present work. The Latin hypercube sampling (LHS) and KMEANS methods were used to produce and reduce the scenario. The proposed framework was investigated in a 33-bus test model. The obtained simulation results were evaluated from different aspects. The TOU and RTP effects and ESS are shown in obtained numerical analysis by considering the operating cost, total social welfare, and the client's utility function.     

冷水机组的优化运行

针对冷水温度、冷却水温度及机组启停控制等影响冷水机组运行的主要因素进行了分析，指出适当提高冷水出口温度和(或)降低冷却水出口温度，采用智能调节策略对多台制冷机和水泵的启动顺序进行合理调配，采用BP网络预测最小预热(冷)期和最长提前停机时间对压缩机进行最优启停控制等，都可以降低系统能耗。     

Optimal control strategies of eight parallel heat pumps using Gaussian process emulator

This study describes the development of the optimal control strategies of eight parallel heat pumps in an existing building. The building consists of seven floors above ground and two floors underground with a total floor area of 22,440?m². The chilled water generated by each of the eight parallel heat pumps runs through a common primary pipe to multiple air-handling units in the building. Because only one flowmeter and two thermometers (entering and exiting) are installed in the primary pipe, the heat removal rate and efficiency of each heat pump are unknown. The existing control of the heat pumps is as follows: if the chilled water return temperature in the primary pipe becomes greater than a predetermined temperature, the controller increases the number of operating heat pumps. The heat removal rate and efficiency of each heat pump were first identified using a Gaussian process (GP) machine-learning algorithm to develop the optimal control strategy of the eight heat pumps. Two GP models, one for estimating the heat removal rate and the other for estimating the coefficient of performance (COP), were developed based on the measured data for 27 days in July at the sampling time of 15?min. After developing the GP models, the authors applied a COP-based sequencing control strategy to the eight parallel heat pumps. The new optimal control strategy is to switch on the heat pumps in order from highest to lowest COP. Compared with the existing control logic, the new optimal control can reduce energy consumption by 20.9%.     

A direct load control strategy of centralized air-conditioning systems for building fast demand response to urgent requests of smart grids

When receiving an urgent request from a smart grid, shutting down part of operating chillers directly in the air-conditioning system in a building can achieve immediate power reduction. However, no study has addressed how to determine the number of chillers/pumps to be shut down and how to regulate the load of retained equipment systematically during DR events. This paper presents a new approach to address these issues based on three schemes. A power demand optimization scheme predicts the building cooling demand and the power limiting threshold in response to a received DR request. A system sequence control resetting scheme determines the number of operating chillers/pumps to be retained. An online control/regulation scheme ensures the system power following the expected profile by regulating the total chilled water flow delivered to the building and therefore the chiller load. It also employs a cooling distributor to distribute chilled water to individual zones concerning different sensitivities/sacrifices to temperature increases. Case studies are conducted on a simulated dynamic building air-conditioning system. Results show that, during DR events, the proposed strategy can achieve the expected power reduction (i.e., about 23%) and also maintain acceptable zone temperature even though uncertainties exist in the prediction process.     

香港环球贸易中心冷却水系统优化控制研究

提出了常规中央空调冷却水系统的优化控制策略.该控制策略是香港理工大学智能建筑研究所与香港新鸿基地产发展有限公司共同研究开发的中央空调系统系列智能优化控制策略之一.这一优化控制策略将应用在香港环球贸易中心.该方法可以自动设置系统冷却水的供水温度(即冷却塔的出水温度)以保证系统自适应于动态的工作条件并保持高效率.该方法在这一建筑及空调系统的虚拟环境下进行了测试和验证.     

Optimal control of structures with convex and nonconvex energy densities and variational and hemivariational inequalities

The paper deals with the identification and optimal control problems of structures involving more than one ‘phase’, as for example contact and noncontact zones, or elastic and plastic regions, which are not known a priori. The behaviour of these structures is described by convex or nonconvex energy functions. After a compact formulation of the problems as variational inequalities (the convex case), or as hemivariational inequalities (the nonconvex case), the optimal control problem is formulated and certain propositions are proved. These propositions are then applied to the optimal control and identification problems in elastoplasticity and contact problems.