LOGO Safety Through Prevention – Safe Switching Using Smart Key Technology Shuqiang Jin, Unitech, Zhuhai, China Nan Liu Youru Huang, SERCC EPRI's 14th.

LOGOSafety Through Prevention –

Safe Switching Using Smart Key Technology

Shuqiang Jin, Unitech, Zhuhai, China Nan Liu

Youru Huang, SERCC

EPRI's 14th Annual Power Switching Safety & Reliability Conference San Diego, California September 20~21, 2010

Contents

• Switching Errors and Impacts

• Traditional Prevention Approaches

• Smart Interlock System (SIS) Technology

• Development/Application of SIS in China

Impacts of switching errors:

• Supply interruptions

• Equipment damages

• Human losses

• Legal liabilities

• …

HumanError

Other……

EquipmentFailure

InadequateProcess

Switching errors can be caused by:

Common switching error types:

1. Energizing when still grounded.

2. Closing grounding switch when energized.

3. De-energizing using disconnects instead of breakers.

4. Load dropping using disconnects instead of breakers.

5. Entering energized switching bays.

Correct switching sequence is the key.

Preventative Measures:Process/Regulation：

Strict regulation and process control in all aspects of electric utility operations: design, construction, operation, personnel training and certification.

Switching order is the center piece that safeguards safe switching

Technology：Locks and interlocking devices – mechanical/electromagnetic/electrical/programmed.

Rule/topology based automated switching order generation.

Process/Regulation：Strict regulation and process control in all aspects of electric utility operations: design, construction, operation, personnel training and certification.

Switching order is the center piece that safeguards safe switching

Technology：Locks and interlocking devices – mechanical/electromagnetic/electrical/programmed.

Rule/topology based automated switching order generation.

Conventional locks and interlocks

They work to certain extent but have limitationsLack of comprehensiveness Lack of flexibility and scalabilityConstrained by complexityLack of coordination between multiple

switching within same station

………

They work to certain extent but have limitationsLack of comprehensiveness Lack of flexibility and scalabilityConstrained by complexityLack of coordination between multiple

switching within same station

………

Preventative measure attributes

1. Reliable

2. Flexible and scalable

3. Comprehensive solution to all the 5 common types

of switching errors.

4. Capable of verifying switching steps before

switching.

5. Ensures that correct switching steps are followed

during switching.

6. Easy to use and simple to install.

Smart Interlock System (SIS)

• Developed by Unitech in 1987 (Mr. Jin Shuqiang)

• Rule/logic and configuration/topology based solution.

• Programmable to suit any voltage levels and station sizes.

• Have developed vast rules base and data base capable to

accurately model complex real world situations.

• One smart key for one station

• Simulate switching to prevent switching errors.

• Enhanced by the latest computing and communication

technologies

Smart Interlock System (SIS)

SCADA Workstation/Software

Smart Key

Locks

Smart interlock System (SIS) Process

Simulate switching step on the workstation.

Switching order generation.

Transferring steps to smart key.

Perform switching steps.

Return smart key to workstation with status updates.

Simulate switching step on the workstation.

Switching order generation.

Transferring steps to smart key.

Perform switching steps.

Return smart key to workstation with status updates.

Switching Order

Open Lock

Logic/Rules/Configuration Databases

• Collect and model switching interlock logic and rules

• Collect and model single line diagram of station/system

• Logic/rules for each bay as well as inter-bay dependency in a station.

Logic DatabaseStatus Database

Software/Model Interaction

•Two databases are stored in a workstation.•The software works with models to display user interface.

•Two databases are stored in a workstation.•The software works with models to display user interface.

LogicDatabase

StatusDatabase

Human InterfaceHuman Interface Work station

Smart Key – Only Need One for Each Station

Works with both electronic and mechanical locks

Capable of multiple wireless communication protocols IrDA Zigbee CDMA/GPRS

Programmable RFID locks. Voice reminder/recorder Ambient temperature -40 ℃ to 80℃

Locks

Embedded with RFID technology

Programmed to work with the smart key

SIS Operation Cycle - Simulation

Simulation Transfer CompletionSwitching

Allowed?Status

DatabaseLogic

Database

SIS Operation Cycle - Transfer

Simulation Transfer CompletionSwitching

SIS Operation Cycle - Switching

Simulation Transfer CompletionSwitching

SIS Operation Cycle - Completion

Simulation Transfer CompletionSwitching

Example: Energize the LineBus

Disconnect #1

Disconnect #2

Breaker

STEP 1: Pre-switching Simulation

Bus

Disconnect#1

Disconnect#2

Breaker

1.Close Disconnect #1

2.Close Disconnect #2

3.Close Breaker

Switchingsequence

STEP 2: Transfer Switching Instructions to Smart Key

1.Close Disconnect #1

2.Close Disconnect #2

3.Close Breaker

Bus

Disconnect#1

Disconnect#2

Breaker

STEP 3: Perform Switching

Bus

Disconnect #1

Disconnect #2

Breaker

1.Close Disconnect #1

2.Close Disconnect #2

3.Close Breaker

1.Close Disconnect #1

2.Close Disconnect #2

3.Close Breaker

STEP 3: Perform Switching

Bus

Disconnect #1

Disconnect #2

Breaker

STEP 3: Perform Switching

1.Close Disconnect #1

2.Close Disconnect #2

3.Close Breaker

Bus

Disconnect #1

Disconnect #2

Breaker

STEP 4: Switching complete-Steps saved

Bus

Disconnect #1

Disconnect #2

Breaker

Performing switching

The unique programmed electronic ID in each RFID equipped locks ensures that only the corresponding smart key can open it. This virtually eliminates opening/closing the wrong disconnects or breakers.

SIS Benefits:

Simulation before switching identifies and eliminates potential errors

SIS

Switching Order

Switching

Switching Order

Switching

Simulation

Verification

Conventional Approach

SIS Benefits:

Multi-switching bay switching coordination

Based on safe switching logic/rules

111-3 h: 111=0,111-1d=0,111-2d=0,111-1w=0,3-7=0,111-2=0!111-3 l: 111=0,111-1d=0,111-2d=0,111-1w=0,3-7=0,111-2=0!

111-2 h: 111=0,111-1d=0,111-2d=0,111-1w=0,111-7=0,111-3=1!111-2 l: 111=0,111-1d=0,111-2d=0,111-1w=0,111-7=0,111-3=1!

SIS Benefits:

One key per station: easy to program and upgrade.

Smart KeyMany keys

SIS Benefits:

Standardized locks. Easy to manage and to maintain

SIS Benefits:

Reliable, flexible, easy to use. For stations of any voltage levels and bus types and setups.

30+ years of SIS development and application

Mr Jin Shuqiang pioneered the SIS technology in 1987. Since then, Unitech Zhuhai and other companies in China continue to research and innovate in the area of safe switching technology.

SIS Deployment in China

Over 22,00 sites with SIS in 2005

SIS Deployment in China (cont.)

The number of switching error related incidents dropped significantly

Interlocking Applications

Three Gorge Project

Shanghai World Expo 500 kV Substation

1000kV Substation

Conclusion

• Smart Interlocking System (SIS) is proven reliable technology that prevents switching errors.

• SIS has significantly reduced accidents and losses related caused by human errors in China.

• We look forward to deploying SIS technology to customers in the United States and other parts of world.

Q&A

Questions？？

LOGOSafety Through Prevention –

Safe Switching Using Smart Key Technology

Shuqiang Jin, Unitech, Zhuhai, China Nan Liu

Youru Huang, SERCC

EPRI's 14th Annual Power Switching Safety & Reliability Conference San Diego, California September 20~21, 2010

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