20 I 0 China International Conference on Electricity Distribution
Advanced Distribution Automation (ADA) Applications and Power Quality in Smart Grids Francisc Zavoda
Department of Electrical Apparatus, IREQ (Hydro-Quebec Research Institute), Varennes, PQ, Canada E-MAIL:
[email protected]
Abstract:
Increasing
management,
complexity
growing
of
demand
power
and
grid
service
its
voltage level at the end of the distribution feeder and the
quality
prototype FL system based on a Voltage Drop Fault Location
and
expectations such as greater grid reliability, efficiency and
(VDFL) technique uses voltage and current waveforms from
security as well as environmental and energy sustainability
distributed power-quality measurements. The impact of these
concerns have triggered the next major step in the evolution of
systems on distribution grid and customers is permanently
the power grid towards a "Smart Grid". It is an expected
evaluated.
result of implementing new technologies in power systems,
Meters
and
major
distribution
equipment
controllers
including renewable energy resources, distributed generation
belonging to different ADA systems can be used as well as
and latest information and communication technologies.
elements
A successful power grid management activity such as DA
symbiosis, between ADA applications and the power quality
of
an
integrated
PQ
monitoring
system.
This
hinges on the information collected from the network itself
monitoring activity, represents one of the advantages offered
using an integrated monitoring system. It enables real-time
by Smart Grids.
monitoring of grid conditions for the distribution system operators and allows automatic reconfiguration of the network to optimize the power delivery efficiency and/or reduce the
Keywords: Smart Grid, ADA, VVC (Volt & VAR Control), FL (Fault Location), PQ (Power Quality), PQ Monitoring, intelligent meters, controllers
impact and duration of outages. Hydro-Quebec is showing leadership in this field with its proposed evolution
plan
1. Introduction
towards a smart grid, which should include: •
Grid monitoring (to improve reliability),
Increasing complexity of power grid and its management,
•
Equipment monitoring (to improve maintenance),
growing demand and service quality expectations such as greater
•
Product monitoring (to improve power quality).
grid reliability, efficiency and security as well as environmental
The utility has ambitious programs. To achieve its energy
and energy sustainability concerns have triggered the next major
efficiency program, HQ has focused on two targets:
step in the evolution of the power grid towards a "Smart Grid".
•
Capacitor banks installation,
•
Volt control.
It is an expected result of implementing new technologies in power systems, including renewable energy resources, distributed
To reduce the outage duration, HQ has focused on fault
generation
location. Pilot projects have been conducted to demonstrate
technologies.
and
latest
information
and
communication
the efficiency of two ADA systems such as: •
Volt & VAR Control (VVC) system
•
Fault Location (FL) system.
The VVC system requires a permanent surveillance of the
2. ADA applications
A successful power grid management activity such as DA hinges on the information collected from the network itself using
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2010 China International Conference on Electricity Distribution
an integrated monitoring system. It enables real-time monitoring of grid conditions for the distribution system operators and allows automatic reconfiguration of the network to optimize the power
HQD GRID 2010 ·2015 I
Transmission! Distribution
delivery efficiency and/or reduce the impact and duration of outages. By definition, an ADA is a
"set of technologies that enable
an electric utility to remotely monitor, coordinate, and operate distribution components in a real time mode from remote locations" . The group of ADA Applications includes:
• Supervisory Control and Data Acquisition (SCADA),
System control CUSTomer
• Volt & Var Control (V VC), .Fault Location (FL), Figure 1: Grid, equipment and product monitoring.
.Feeder Reconfiguration (FR) (Self Healing),
• FLlSR (Fault Location, Isolation, and Service Restoration), 4. Volt and VAR control
which is a hybrid of FL and FR An integrated PQ Monitoring is not a real ADA application,
The V VC application is based on the CV R (Conservation
but this activity can be easily performed in symbiosis with the
Voltage Reduction) concept, which is associated with having the
above mentioned applications.
customer's voltage at the lowest level consistent with proper operation of equipment and within levels set by regulatory
3. Hydro-Quebec and smart grid
agencies and standards setting organizations. Hydro-Quebec is showing leadership In this field with its
Hydro-Quebec aims saving energy by controlling the voltage
proposed road map towards a smart grid, which should include
level
(see Figure 1):
distribution network.
• Grid monitoring (to improve reliability),
and
by
managing
the
reactive
power
(VAR)
in
the
To fulfill this goal, the utility decided to use a V VC system,
.Equipment monitoring (to improve maintenance),
which requires a permanent surveillance of the voltage level at the
.Product monitoring (to improve power quality).
end of the distribution feeder and the installation of switching
The utility has ambitious programs. To achieve its energy
shunt capacitor banks along the feeders (see Figure 2 a). In 2005 and 2006, Hydro-Quebec has done some experiments
efficiency program, HQ has focused on two targets:
•Capacitor banks installation,
at Pierre-Boucher (PBR) substation (in suburban Montreal) to find
.Volt control.
the effectiveness of the conservation voltage reduction for energy
To reduce the outage duration, HQ has focused on fault
saving and to evaluate the economic feasibility of the concept [1]. In the fall of 2008,
location. Pilot
projects
have
been
conducted
to
demonstrate
the
• Volt & VAR Control (V VC) system,
system losses. Basically, the voltage regulation system at the substation was replaced with an intelligent system that uses
.Fault Location (FL) system. impact
of
these
systems
customers is permanently evaluated.
commissioned a voltage and VAR control system named CATVAR at PBR substation to reduce energy consumption and distribution
efficiency of two ADA systems such as:
The
Hydro-Quebec Distribution (HQD)
on
distribution
grid
and
network measurements to maintain a stable voltage level at the end of the feeder that is close to the lower limit specified by Standard CSA-235. The CATVAR system also analyzes the network's VAR
20 I 0 China International Conference on Electricity Distribution
3
requirements and orders the switching on and off of shunt
Intelligent Maintenance for Electrical Lines),
capacitor banks when required.
technique.
based on this
One of the goals of this pilot project was to determine whether the fact of maintaining a lower medium voltage near the lower limit of Standard CSA-235 would have an impact on the number of voltage sags experienced by customers. Another
goal
was
to
prevent
potential
power
problems created by the switching operations of
quality
1.2-MVAR
capacitor banks. To do so, EM TP power system simulations were conducted
and
the
results
were
compared
with
real
life
measurements made on the network. Figure 3: Monitoring device (a) indoor; (b) outdoor. The average absolute error of MILE system is less than 200m. This error value reflects not only the accuracy of the numerical assessment but also errors in the feeder characteristics database and inaccuracies in the actual distance evaluation.
6. ADA applications and data acquisition requirements To be able to accomplish their duties, these ADA systems
Figure 2: (a) Capacitor bank; (b) Voltage monitoring device
require information, such as voltage and current measurement values. collected from the network itself.
5. Fault location
.V V C/CATVAR The most known methods used for fault location are:
• Voltage and current RMS values measured at the substation and voltage RMS values measured at the end of
.VDFL (Voltage Drop Fault Location ) that:
the feeder (5 minutes average values in general and 1 minute
• Uses distributed PQ measurements (an average of 4 monitoring sites along the feeder is required).
or 30 seconds average values in particular). .Fault Location/MILE
.Based on voltage sags triangulation technique that shrinks the zone of investigation (low number of possible
• Waveforms
of
voltage
and
current
recorded
at
fault locations).
different locations along the feeder when interruptions and
.lBFL (Impedance Based Fault Location), which:
sags occur. The accuracy of the data acquisition process is an important
• Uses centralized PQ measurements (voltage and
factor, critically affecting the efficiency and reliability of these two
current waveforms recorded at substation).
• Based on the calculation of total line impedance from
systems.
the measurement location (substation) to the fault location. MILE,
the
FL
system
designed
and
developed
by
Hydro-Quebec, is based on VDFL technique, and uses voltage and current waveforms from distributed power-quality measurements along the feeder (see Figure 3). So far, seven distribution feeders have been monitored with an automated specialized software package MILE (Maintenance Intelligente de Lignes Electriques or
6.1
Data acquisition required by the Volt & VAR
Control System The CATVAR system requires voltage level measurements from substation bus bar or feeder departure and from the end of the 3-phase main feeder. A substation transformer supplies 3 to 4
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2010 China International Conference on Electricity Distribution
feeders. When one of the voltage levels monitoring devices at the end of these feeders is malfunctioning the voltage adjustment at
. . .... _I__ 1;i.p.
LTC (Load Tap Changer) by CATVAR system is disabled. To avoid this kind of problems, CATVAR will be equipped with an integrated
management
system
based
on
state
estimators.
Enhanced state estimators require more information about the power flow and more voltage and current monitoring points. Figure 4 shows a theoretical distribution of voltage and current monitoring points providing information required for a dynamic modeling of the load.
sean
keq. S!WIC., 088d blind. 1"-. Aa:umqo 0 7�
Figure 5: Waveforms Diagram; Data required by MILE (FL)
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