1、,Unit FourteenControl and Building Automation System,What is an intelligent building?,Schematic Diagram of an Intelligent Building System,Up to now, there has not been a universally accepted definition for an Intelligent Building. Most existing definitions of IB around the world centre on the need f
2、or a building to be suitable for the occupants to work and live in safely, comfortably, effectively and efficiently. “Intelligent building is something that make stupid people feel not as stupid as they are”.,Intelligent Building can bring us Reduced Resource ConsumptionBoth home and building techno
3、logy offer tremendous potential savings through intelligent controls. Optimized Convenience and More ComfortApart from minimizing consumption costs, private home owners will be interested in higher levels of convenience, safety and security.,Smart Home is an integration of various systems at home su
4、ch as security, home automation, lighting control, CCTV and entertainment system which is coordinated by a smart home controller and controlled by users using various centralized command interfaces such as a touch screens, keypads, universal remote controllers, internet browser, telephone, and even
5、your LCD TV screen.,Smart Home Systems,CCTV: Closed Circuit Television CCTV: China Central Television,On/off Control,The control device can be positioned only to a maximum or minimum state (e.g., on or off). Because On/off control is simple and inexpensive, it is used extensively for both industrial
6、 and commercial control. A typical home thermostat that starts and stops a furnace is an example of On/off action.,Floating Control,Dead (neutral) zone,盲区 停滞区,In floating control, the controller can perform only two operations moving the controlled device toward either its open or closed position, u
7、sually at a constant rate. Generally, a neutral zone between the two positions allows the controlled device to stop at any position when the controlled variable is within the differential of the controller. When the controlled variable falls outside the differential of the controller, the controller
8、 moves the controlled device in the proper direction.,open,shut,Time,Upper limit,Lower limit,neutral zone,Temperature,Valve,set point,controlled variable,proportional band,output,offset,Proportional control requires a continuously variable output of the controlled device. The control system produces
9、 an output which is proportional to the error signal, i.e. the difference between the value of the controlled variable and the set point.,Proportional control,signal,response,Integral control,Derivative control,signal,response,Proportional plus Integral (PI) Control,Proportional-Integral-Derivative
10、(PID) Control,Proportional Action.,Closed loop control,Feedback,A closed loop or feedback control measures actual changes in the controlled variable and actuates the controlled device to bring about a change. The corrective action continues until the variable is brought to a desired value within the
11、 design limitations of the controller. This arrangement of having the controller sense the value of the controlled variable is known as feedback.,Example of Feedback Control Room Air Temperature Control,Open loop control,An open loop control does not have a direct link between the value of the contr
12、olled variable and the controller. An open loop control anticipates the effect of an external variable on the system and adjusts the set point to avoid excessive offset. An example is an outdoor thermostat arranged to control heat to a building in proportion to the calculated load caused by changes
13、in outdoor temperature. In essence, the designer presumes a fixed relationship between outside air temperature and the heat requirement of the building and specifies control action based on the outdoor air temperature. The actual space temperature has no effect on this controller. Because there is n
14、o feedback on the controlled variable (space temperature), the control is an open loop.,Single-Seated Valves Double-Seated Valves单座阀 双座阀,Three-Way Mixing Valves Three-Way Diverting Valves三路混合阀 三路换向阀,Sensors Temperature Sensors Humidity Sensors Pressure Transmitters and Transducers Flow Rate Sensors
15、Indoor Air Quality Sensors Lighting Level Sensors Controllers Pneumatic Receiver-Controllers Electric/Electronic Controllers Digital Controllers Thermostats,1. Control ModesOn/Off control Proportional control Floating control Integral control Derivative controlVariation and Combination of basic mode
16、s 2. Open and closed loop control open loop control closed loop control 3. Building Automation Systems3.1 General3.2 Basic Considerations3.3 Computer Based Systems,Frequently used words and phrases:control mode 控制模式 On/Off Control 开/关控制 Proportional control 比例控制 Floating control 浮动控制 Integral contro
17、l 积分控制 Derivative control 微分控制 Proportional plus Integral (P+I) Control 比例加积分控制 Proportional plus Derivative (PD) Control 比例加微分控制 Proportional plus Integral plus Derivative (P+I+D) Control 比例加积分加微分控制 final control element (FCE) 终端控制元件 Open loop control 开环控制 Closed loop control 闭环控制 signal 信号 heater
18、battery 加热器组 air curtain 空气幕 sensor 传感器 electro-mechanical system 电动机械系统 pneumatic system 气动系统 pressure switch 压力开关 humidistat 湿度控制器 time switch 定时开关 building automation system (BAS) 建筑自动化系统 energy management system (EMS) 能源管理系统 direct digital control (DDC) 直接数字控制,1. A controller can be made to oper
19、ate a final control element (FCE), e.g. a valve, damper, or luminaire in a number of different ways in response to a signal.2. The control mode does not define the means by which control is effected, which may be through mechanical, electro-mechanical, electronic or pneumatic systems.3. The control
20、sensor usually takes the form of an on/off thermostat, pressure switch, humidistat, time switch, etc. and operates such that below the set point the contacts open.,controller: 控制器 final control element (FCE): 终端控制元件 damper: 闸板 luminaire: 照明 signal: 信号,control mode: 控制模式 electro-mechanical: 机电的 pneum
21、atic: 气动的,on/off: 开或关 pressure switch: 压力开关 humidistat: 湿度调节器 恒湿器,4. Proportional control action refers to a control element having an output signal proportional to its input signal.5. If the scale range of a temperature controller is from 0oC to 100oC and the proportional band setting is such that
22、the controlled variable must change from through 40oC to 80oC to make the valve move from full open to shut, then the proportional band is (80-40)/100=40%.6. This mode of operation depends on the use of a dead (neutral) zone in the controlled variable. In this zone the correcting element is not powe
23、r controlled and remains in its last pulsed position until the controlled variable moves outside the dead zone.,proportional control: 比例控制,dead (neutral) zone: 停滞区 中性区 correcting element: 修正元件 pulsed: 搏动的 跳动的,proportional band: 比例带 full open: 完全打开,8. This action is used to eliminate overshoot during
24、 a fast load change. Derivative control is mainly applied in special process systems.9. While floating and proportional control actions may be used on their own, derivative control must always be used in combination with proportional or floating action.,overshoot: 超出 超过 过分 load change: 负荷变化 derivati
25、ve control: 微分控制,How to translate?,10. Control systems are applied to control loops, each loop normally comprising one section of an overall plant, e.g. reheater, smoke alarm.11. When the condition of the controlled variable changes in closed loop control the sensor detects the change and initiates
26、correcting action to final control element.12. The effect of this is reflected in the controlled variable and reassessed by sensor which continuously provides feedback to the controller.,control loops: 控制环路 comprising: 构成 reheater: 再热器 smoke alarm: 烟雾报警器,closed loop control: 闭环控制 detect: 探测 initiate
27、: 触发 开始,reassess: 再评估 feedback: 反馈,13. The simplest form of such a loop would be the detection of smoke where a local/or remote alarm is initiated by a smoke detector without any feedback to the smoke sensor.15. Most thermostatic control manufacturers now market buildings automation systems to monit
28、or and control other building services such as energy, security and fire protection systems.,alarm: 报警器 smoke sensor: 烟雾传感器,thermostatic: 温度调节装置的 market: 使进入市场 security: 安全 fire protection systems: 防火系统,16. It is always advisable to question the level and validity of the software offered to perform
29、the tasks required in the context of building services automation.18. One other area which requires emphasis is the possible susceptibility of all processor based systems to electrical interference, however caused.,advisable: 可取的 明智的 question: 提出问题 质询 validity: 有效性 context: 上下文 领域,emphasis: 强调 susce
30、ptibility: 易感性 interference: 干扰 干涉,19. The principles apply whether the system has one unit with 10-20 points or multiple processors and outstations serving 10,000 points.20. It is essential that the specification for any BAS is precisely detailed in terms of all performance, requirements, functiona
31、l sequences and clearly defined interface conditions for every facility required.,point: 控制点 outstation:设在边远地区的分站 边远哨所 远程控制中心,BAS: building automation systems 建筑自动化系统 detail: 详述 细说 in terms of: 按照 根据 functional sequence: 功能顺序 interface condition: 界面条件 facility: 设施,22. The centralization of the logic
32、 equipment allows greater flexibility of operations than conventional hard wired systems and also frees maintenance staff from watch keeping duties, enabling more effective use of manpower.23. It must be considered very early on in the building/plant design concept. If it is added at a later stage i
33、t will duplicate a number of other elements which are complete in themselves.,centralization: 集中 logic equipment: 逻辑设备 flexibility: 灵活性 hard wired system: 硬件系统 staff: 人员 职员,later stage: 后期 duplicate: 复制 使成双倍,25. If process control is to be achieved by direct digital control (DDC) then savings will o
34、ccur in the elimination (of) local loop controllers and in the avoidance of duplicating sensors for control and monitoring purposes.,process control：过程控制 direct digital control (DDC): 直接数字控制 elimination: 减少 avoidance: 避免,26. Planned and programmed maintenance schedules can also be produced and monitored by the computer based systems but this normally requires a large memory storage capability and considerable project orientated input data.,schedule: 日程计划 时间计划 orientate: 调整方向,
