IEEE Power & Energy Magazine - March/April 2018 - 52

Power System
Cognitive
Information

figure 5. A system diagram and appearance of the ISC system.

Control
Signal

Same as the Figure Above

Load Shedding

ISC-T

Generator Selection
for Primary Control
Supporting
Information for
Additional Control

Power System
Topology Search
Stability Calculation

Generator Tripping

ISC-T
Additional Control
(ISC-C Calculate)

Primary Control
Additional Control
(ISC-C Calculate)
Primary Control
(ISC-P Pre-Calculated)

FSC:
Transmit Control Signal Transmit Control Signal
Every 10 s
* Power System
Cognitive
Information
ISC-C (East Area)
Same as the Figure Above

Real-Time Sampling Data
Measurement
Information

ISC-S (Measurement)

Fault
Online Information

FSC
TSC

ISC-P

Hitachi

ieee power & energy magazine

Online Information

TSC:
Every 30 s
* Primary
Control Target
* Supporting
Information
for Additional
Control

TSC
Start-Up Decision

Toshiba

IP Network

ISC-C (West Area)

Mitsubishi

FSC
Start-Up Decision

Relay's
Activation

Relay's Activation

ISC-S (Fault Detection)

Mitsubishi
Optical
Communication, etc.

Latest Relay Equipment
Latest Relay Equipment
High-Performance Electronic Computers
52

recognizes both control signals from Isc-c and
fail-safe relay activation, such as 91d (power flow
oscillation protection). In the fsc function, Isc-P
sends network topology information for each
surveillance point to Isc-c based on online data
from rtus. Isc-s sends fault detection data from
protection relays, circuit breakers, and real-time
frequency to Isc-c. Isc-c sends control signals
to Isc-t based on network topology from Isc-P
and fault detection and real-time frequency from
Isc-s. Isc-t executes load and generator shedding when Isc-t recognizes both control signals
from Isc-c and fail-safe relay activation such as
95uf (under frequency). thus, each Isc component has multiple roles to be able to realize the
wide-area Pcs functions.
transmission line power flows tend to fluctuate due to der (PV) intermittent generation
output. By combining data from both Isc-P precalculation results and Isc-s real-time power
flow, Isc-c can optimize the generator/load
shedding amount to keep the transient (angle)
stability of the transmission network. In addition
to adapting to the large number and total production of der (PV) interconnections, the Isc
system can also coordinate tsc/fsc functions
at all voltage levels (500, 275, 154, and 77 kV)
in the cePcO transmission network. the Isc
can adapt to various future changes like the addition of large-scale thermal generation interconnection (such as the West-nagoya no. 7 series
2,376-MW liquid natural gas-fired generation in
March 2018 and taketoyo no.5 1,070-MW coalfired generation in March 2022) in the 154-kV
transmission network or increases of cross-regional power interchange among different t&d
supply areas. the Isc system also optimizes its
telecommunication network. By adopting the
ring telecommunication method among Isc-cs,
Isc-ss and Isc-ts (about 90 equipment units),
it reduces telecommunication equipment usage
to less than half when compared to traditional
tsc/fsc systems.

Evolution in DMS
with Smart Meter Data
the cePcO distribution network has approximately 8,700 distribution feeders, 2.8 million
poles, 70,000 sectionalizing switches, and 1.6 million pole-mounted transformers. A main function
of the distribution management system (dMs) is to
monitor and control distribution equipment within
the entire network. Various network changes
include diversified energy usage by customers,
mass PV penetration, and smart meter installation.
march/april 2018

Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - March/April 2018