Download Diapositive 1 - CIRED - CIRED • International Conference on

Frankfurt (Germany), 6-9 June 2011
Smart Grid Protection in
China
Wu Guopei
Guangzhou Power Supply Bureau
Guangdong Power Grid,
China
Frankfurt (Germany), 6-9 June 2011
Contents

Smart grid in China and the challenge for
protection

Change from relay protection to grid protection

Concept of grid protection system

Reach of grid protection

Case study
Frankfurt (Germany), 6-9 June 2011
Smart Grid in China
China is speeding up the infrastructure of
smart grid
 Main characteristics of Smart grid
 self-healing and adaptive
 safe, stable and reliable
 fine compatibility
 high quality and efficiency
 coordinated and economic
 friendly interaction with the users

WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
New Challenges for Smart Grid Protection
 Adaptive
Flexible topology structure
 Connection with distributed generators

 Self-healing
Preventive control under normal
operation condition
 Automatically recover to normal state
with minimum manual intervention

WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
Change from relay protection to
grid protection

Three-defense line for the safety of
power system

First defense line ：Conventional relay
protection
To safeguard power system stable operation by
fast and selective tripping of fault elements.
Frankfurt (Germany), 6-9 June 2011
Change from relay protection to grid
protection

Second defense line：Power stability
control system
To avoid system out-of-step by applying load
shedding and generator shutdown according to
pre-set control tactic.
Frankfurt (Germany), 6-9 June 2011
Change from relay protection to grid
protection

Third defense line：emergency control
Designed to prevent from system collapse and
large area blackout using out-of-step islanding
and frequency & voltage control.
Frankfurt (Germany), 6-9 June 2011
Concept of grid protection




Possibility grid protection:
Development of information and storage
technology eliminates the information
isolated island in power system.
Safe and realtime information exchange
Extension from substation domain
information interaction to power grid wide
area information interaction.
Frankfurt (Germany), 6-9 June 2011
Concept of grid protection

Goal：

Realize integrated and optimized
protection and control tactic instead of
isolated three-defense line protection
system
Frankfurt (Germany), 6-9 June 2011
Research of grid protection



Optimized protection performance
Limit of conventional protective relay: The
selectivity of protective relays, especially back up
protective relays, are dependent on the current,
impedance and time settings, which may cause
operation time delay and loss of selectivity.
Accurate fault locate and precise fault isolation can
be achieved by using wide area fault distinguishing
information at each node.
Frankfurt (Germany), 6-9 June 2011
Research of grid protection


Fast power recovery in regional power
grid
When the substation is loss of power due to
power supplies out-of-service, the power supply
in other substations will be connected according
to system operation mode and topology state.
Frankfurt (Germany), 6-9 June 2011
Research of grid protection




Improve the safety and reliability of
distribution network after power recovery
Overload caused by power recovery may affect
the power grid reliable operation
Load shedding shall be adopted to ensure the
power supply to important consumers.
Acquire pre-fault static load information through
the wide area information interaction with EMS,
and optimize load shedding strategy to
maximally protect reliable power supply.
Frankfurt (Germany), 6-9 June 2011
Research of grid protection

Improve the safety and reliability of distribution
network with distributed power supply




When distributed power supplies are connected to
distribution network, the conventional relay setting
regulations can not meet the requirements of system
selectivity.
The electrical character are varying according to the type of
distributed power supplies during system fault and grid
interconnection.
Fast and precise fault locate and fault tripping using wide
area measurement data
Check if the distributed power supply can restored to
interconnection or isolated island state after fault is cleared,
and ensure the safe and reliable operation of distribution
network by applying grid interconnection control and load
shedding.
Frankfurt (Germany), 6-9 June 2011
Case study – Grid protection distribution
network in China Southern Grid

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
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Located in financial high-tech service area of
Guangdong
Includes 2 substations, 65 kilometers
distribution lines, 58 switch room ring main
Build distributed Intelligent
Self-Healing Control System
Based on Multi-Agent
The goals: average fault
outage time 5.2min/year
WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
Implementation of Grid protection


Taking into account the real-time performance
of feeder automation devices (FA) and
information completeness of distribution
automation system (DMS), to raise the smart
level of real-time control.
Distribution terminals with enhanced functions
will be used as agents of grid protection and
control system, to realize local signal
acquisition pre-treatment, logic determination
and implementation of remote commands.
WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
Implementation of Grid protection


Embedded central control
stations with rapid information
processing ability will be set up,
for fault criteria logic
calculation based on wide-area
information, to realize rapid
fault location.
System configuration tool shall
be provided with graphic
interface to realize system
configuration for IEDs of smart
distribution network protection.
WU– CHN – RT 3b
System
配置工具
Configuration
Tool
Embedded
Control
Device
Real-time Network
Agent
Agent
Agent
Frankfurt (Germany), 6-9 June 2011
Implementation of Grid protection

Wide-area information protection logics such as
improved directional pilot protection suitable for
distribution grid will be used, to effectively
determine distribution grid fault zone connected
with distributed power source at load terminals.
WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
Implementation of Grid protection


Realize power restoration path selection function
based on grid topology, assisted with load control
technologies such as LF load disconnection, to
realize rapid load restoration and load
optimization and re-distribution.
Micro-grid frequency and load control technology
with multi-DG access will be tried, for distribution
grid multi-DG coordination control in island
operation.
WU– CHN – RT 3b
Frankfurt (Germany), 6-9 June 2011
Thank you for your attention !
WU– CHN – RT 3b