Building Automatic System (BAS) or

Environment Management Control System (EMCS)

The general operation of Metro and Light Rail Transit are controlled by electrical devices and control systems. The subway ventilation air condition system is the most crucial system to satisfy and improve the internal air circulation for the humans and operating devices. It is a necessary and important function of the subway system. Devices like lighting, drainage, gates, guide, PSD, escalate, are directly serving the passengers. Its operating status concerns much to the overall metro service and quality. BAS supervise and manage all the operating devices placing an important role in the whole metro operation. EMCS or BAS in China's metro specification, is a typical integrated system. BAS also has three basic characteristics: open system, applied requirement and interface. BAS system devices are mainly found in the ventilation air condition system of the station and tunnel.

1. Station Ventilation System Devices

• Devices in the public area ventilation air-con system
• Devices in the station and control room
• Air condition water system device
• Various sensor, executor

2. Tunnel Ventilation System Devices

This devices operate in the tunnel area which includes the section tunnel and station tunnel. In normal condition, it is use for ejecting the hot air and change air. In emergency condition, it is use for ejecting the smoke, hot air and wind. The devices installation location, number, power, and operating mode are decided by the designer group unit. HollySys will only introduce the operating characteristic, supervision method and the interfaces.

• TVF install at 2 sides of station platform layer, at the middle of long tunnel section.
• wiring tunnel fan, install at wiring tunnel, tunnel in-fall
• Station tunnel fan (OTE and UPE), 2 sides of station concourse
• Relative combination fan, near various fans and air shaft
• Air curtain in the tunnel portal
• Tunnel section fan, station tunnel section fan and jet fan are ternary status devices: forward, reverse and stop with multi-status feedback point. Others are 2-state devices.

3. Drainage Device

Generally, contains two types of device control - motorised butterfly valve and water pump.

4. Lighting Indicator

Lighting indicator includes operating light, adv light; enter/exit light, section light, emergency power light and other power not related to fire control.

5. Lift and Escalator

Station public area device, located in enter/exit of the station public area.

6. Platform Screen Door (PSD)

If PSD is use, BAS will supervise; control and managed with the PSD control system. PSD install at platform - boundary between platform and tunnel to isolate station and tunnel. It closes when there is no train stopped at platform and opens or closes with carriage door when there is a train stopped at platform. PSD is a system controlled by a specific controller. The controller connects to station communication controller by serial link connecting with station network.

7. Airtight Blast Door

The Airtight blast door is located in tunnel, normally in open status. BAS only supervise it by IO interface without control

8. Emergency Flood Gate (FG)

It will be equipped in the tunnel through the river or lake. BAS supervise FG via IO interface.

Device Distribution Characteristic

Understanding and confirmation of the device distributing characteristic is a pre-requisite of system design.

BAS: System Function

Different layer of the BAS system has different operating functions. BAS function can be implemented and completed with the excellent coordinate of various layer.

1. OCC BAS function

OCC supervision/control system is the core of BAS system. Its function design should be metro operation and maintenance- oriented, and focus on daily dispatch and disaster proof function, supporting general supervion/control/management. It implements functions like data setting, key device (i.e. tunnel fan) remote control, group control and mode control for dispatch and operation management. Kinds of high efficiency and applicable supervision/control methods, which will be used for operation management, can implement area supervision/control operation, will be provided for maintenance and environment operator.

2. OCC supervision/control function

• device supervision/control/management
• operation dispatch/management
• online help and decision support
• system security management
• HMI
• synchronization

3. OCC BAS maintenance function

Generally, OCC maintenance function will be implement integrated with OCC supervision/control system. But sometimes it needs to equipe independent maintenance system and training systems at depot. At that time system logic lever is the same as OCC supervision/control system. OCC MACS pay more attention to general supervision/control/management, while depot system pay more attention to BAS maintenance. According to requirements, this system can work as OCC MACS backup with the capability to implement supervision/control/management functions. The maintenance function contains:

• whole line BAS system project management
• whole line BAS system supervision/control/maintenance
• whole line backup supervion/control/operation

4. Station BAS function

Station BAS is a independent system, take station as unit to implement station BAS function. It's main purpose:

• In normal condition, provides various, complete supervision/control methods to implement supervise/control operation, real-time control. It can also achieve energy saving and control optimizing purpose by advanced, applied control calculation.
• In abnormal condition, provide convenient coordinate and dispatch methods to satisfy and react to special condition's requirement, and also for finishing mode control according to operation or request trigger.

Its main function includes:

• real-time supervision control and coordination control
• station environment parameter supervision control
• station air condition control
• big system device optimize and intelligent control
• device control
• disease proof coordination control
• emergency backup control
• subsystem independency
• intelligent, optimize and control
• user friendly supervision control
• system security
• alarm supervision control and management
• fire coordination function
• system resume and maintain
• system diagnose
• system status supervision control
• parameter system

5. Local function

• signal acquisition, transmission and transfer
• display and diagnose
• data transmission and protocol transfer function
• single device control function
• interlock control

BAS: Interface processing

BAS is an interfacing system. One character of interfacing system is processing for various interfaces. BAS need implement supervise and control controlled object via various interfaces. At the same time it's not a isolate system, obviously it should coordinates with other subsystems, such as FAS, LV, communication, MCS, etc.

1. Interface with FAS

When BAS is responsible for fire proof, actually it acts as coordination control system of FAS. According to coordination descriptions in national standard--- , BAS is responsible for multi-fire proof functions. This standard stipulates technique requests for control method, respond, and feedback display. BAS and FAS usually interfaces at station control room. IBP controller is used for BAS side interface device.

2. Interface with LV

Generally speaking, BAS control electricity equipment through interface of LV. Normally, BAS system uses MCC to centralize control for fan and fan valve, while BAS implement device control by interfacing MCC.

3. Interface with MCS

If BAS interconnect with MCS, BAS OCC and station control function should be done by MCS, while BAS as an subsystem of MCS, is not an independent system. BAS generally use network port interface with MCS. MCS directly change data with BAS controller.

SCADA or PSCADA System (Power Supervisory Control And Data Acquisition)

SCADA system (telecontrol system) develops based on requirements to remotely supervise and control power supply system device (such as breaker, isolate switch). It is implement with remote control, remote viewing, remote test, remote signaling and remote regulation functions for the whole line substations important electric equipments. It has unchangeable effect for improving power network, running reliability, safety and economy benefit, releasing operator burden, implement power dispatch modern and automatic, improving efficiency and dispatch lever.

SCADA basic composition

SCADA is an automatic distributing control system. Form up to down: dispatching center LAN, communication channel, substation management layer, field communication network, interlayer devices.

SCADA function

1. OCC Function

• Information process display
• Powr supply system data archives and statistics report
• HMI
• Information printout
• Trend display
• HMI access and display
• Information query request
• Software online maintenance
• Emendation
• Development system fault-tolerant capability
• Self-diagnosis and self-resume

2. Substation Automatic System Funtion

The whole substation automatic system should include interlayer device (Measurement and Control Equipment ), network and management layer. Interlayer device divide to AC system (10 or 35KV device), traction system (750 or 1500V device), LV sytem (0.4KV device) and other system (such as power screen control equipment, transformer measurement and control equipment, etc). No matter how device changes supply scope, it mainly achieves following functions:

• Interlayer device information collection and control send control request
• Completely communicate with various intelligent interlayer device
• Substation internal interlock, coordination implements
• Communicate with upper layer supervision system and information changing
• If needs, it should have substation HMI to realize supervision and control for substation device

3. System interface

• Interface with SIG
• ICC and SIG interfaces at OCC SIG equipment room.

4. Substation automatic system internal interface

The substation has complex internal interface systems.Interface is an crucial factor which can influence substation automatic system project schedule. The interfaces are:

1. hardware
2. serial
3. bus

Fire Alarm System (FAS)

The purpose of FAS is to detect fire as early as possible and send emergency fire alarm, and to activate relative fire-proof, fire distinguish device. FAS can automatically detect fire occur at the beginning and send emergency alarm to organize passenger evacuation thru alarm devices. At the same time it activates ventilation and smoke/fire proof distinguish devices to facilitate human evacuation and proof fire development which means fire control and distinguish.

FAS play a special part at metro/subway subsystem. In one hand, it's the most crucial part of metro/subway disaster proof. On the other hand, it's construction should obey country local fire control laws and regulation. FAS contractor is highly limited by these rules.

FAS equipment

Mainly consist of 4 parts of functional devices:

• fire trigger device
• fire alarm control device
• fire alarm device
• fire coordination control device

FAS function

Metro disaster-proof alarm system functions divided to central and station functions.

FAS central function

FAS central function mainly supervise all area fire alarm, fire control coordination and failure for whole line station, tunnel section, OCC building, depot, parking area, main substation etc. OCC FAS should coordinate with other subsystems as well:

• coordinate with cable/cordless phone
• coordinate with PA system
• CCTV

Station Function

FAS station function mainly contains supervision, alarm, control and coordination with other systems.

• supervision mode
• alarm mode
• fire control coordination mode
• disaster-proof communication mode
• disaster-proof extension integration
• disaster-proof extension network communication

Fire control coordination control cabinet

At station control room, key devices which should be running at fire condition (such as fire service pump, sprinkler pump, smoke ventilator), they will be equipped with fire control coordination control cabinet for manually control during emergency conditions.

Interface with FAS

• Interface with gas extinctor
  If the gas extinctor system use detecting, control, extinguishing scheme, the FAS/gas extinctor interface will be very simple and convenient, just by using system internal network card. This internal connection of the some system ensures the complete, safety, saving investment. It also benefits future maintenance management of the system. If the fire distinguish system is different from FAS, it needs interface negotiation between systems. At that time, FAS contractor should be mostly considered.

• Interface with master clock
  Adopts RS422 synchronism interface and interfaces at master clock rack of communication system

• Interface with EMCS/BMS
  FAS and EMCS equips data transmission interface on MCS lever and sub-control lever. The interface located in disaster-proof master and slave. The request sent by disaster-proof system has highest priority. When fire occurs, it can send request to EMCS via station data interface. EMCS change the running status of controlled devices to predefined fire mode.

Passenger Information System (PIS)

The operational management of modern metro subway rail system pays more and more attention to passenger services and man services. Some famous subway pays much attention to PIS construction which mainly intension concerning passenger service. especially in 2003, Korea Taegu subway fire atonements the whole world, and then PIS is placed to the important class. Operation mode changed from train focus to passenger focus.

PIS basic concept is: metro operation service provider by using mature available network, multimedia transfer, display techniques, display specific information in specific time to specific passenger.

In normal condition, PIS can real-time provide multimedia information such as train schedule, government note, travel reference, found information, advertisement, etc; in fire or congestion condition, it dynamically provides emergency vacation indication. PIS provides all mentioned information for passengers to make them walk safely, efficiently by train and make metro train operate efficiently and more safely.

• Classify from architecture: central system, station system, intra-sis, network system, advertising system.
• Classify 4 layers for control function: namely information source, central broadcast control, station broadcast control and station broadcast device.