FER 58 3 115 2012

FER 58 3 115 2012
Devices for Facility and Energy Monitoring Systems
–Expansion of “F-MPC Series”–
TAZAWA Yuji † TANI Toshiaki † MACHIDA Satoshi †
Distinctive Technologies of Latest Devices
ABSTRACT
Fuji Electric provides various products to reduce energy consumption and improve power supply reliability in
power distribution systems. It offers several new products that promote a recent energy saving trend. One is the
“F-MPC04E”, a compact electrical power meter that efficiently monitors terminal equipment, such as distribution
panels. Another is the “F-MPC I / O unit”, a digital input and output unit which measures electrical metering pulses,
monitors non-electric energy or other physical flow value, and outputs warnings. One more is the “F-MPC Igr”, an Igr
type insulation monitoring device that constantly monitors for leakage of electricity from critical intelligent equipment.
Combined with the existing “F-MPC Series” instruments and package software, it can provide electrical power monitoring and insulation monitoring simultaneously.
With the revision of the Japanese “Law Concerning
the Rational Use of Energy” (Energy Conservation
Law) in 2010, the target of mandatory energy management has expanded from each factory and business office to each company and corporation. Furthermore,
the range of factories that are obligated to monitor
energy consumption was expanded, commercial sector
including offices and convenience stores was added,
and the number of factories, offices and stores that are
subject to this law has increased significantly.
To solve the power supply shortage stemming from
the Great East Japan Earthquake in March 2011, not
only must the total energy usage be reduced and leveled through “energy savings,” but suppression of the
maximum power usage must also be stepped up to the
higher “power cutting-down stage.”
Moreover, as reduced energy usage is demanded,
the automated inspection of facilities and longer intervals between periodic inspections are requested for facility maintenance work mainly at business sites such
as data centers and semiconductor fabrication plants
where it would be difficult to stop the facility.
2. Background of the Development
As shown in Fig. 1, Fuji Electric has advanced its
response to meet the needs for energy monitoring primarily for the electric power in an electricity distribution system and for the status monitoring of electric
equipment.
Through ascertaining these needs, this paper introduces monitoring system and the latest devices that
aims to provide a stable monitoring of equipment and
†
Fuji Electric FA Components & Systems Co., Ltd.
to realize energy savings and power cutting-down.
Unlike large-scale factories, business office which
has newly added to the energy monitoring market
by the revision of the Energy Conservation Law, are
often unable to set up energy experts into the field.
For this reason, Fuji Electric has been offering the
“F-MPC Web unit” developed on the concept of easyto-construct energy visibility system, even when an
expert is unavailable. The F-MPC Web unit allows collected data to be checked easily from a general-purpose
browser with Web capabilities. As analysis function
screens, such as graphs of electric power consumption, trend information, group comparisons, and unit
consumption display per production volume, can be
viewed without dedicated software, the data can be
verified at any time by all users, not just administrators, thus facilitating energy visualization easily.
Fuji Electric has proposed a power and energy
monitoring system that uses “F-MPC Series” equipment and ranges from a high-voltage power distribution system to a terminal system (see Fig. 2).
Fuji Electric has also developed the “F-MPC04E”
Previous technology New technology
1. Introduction
Insulation monitoring device
I/ O unit
Multi-function relay for
distribution system protection
Power measurement and earth
leakage monitoring equipment
Energy monitoring unit
Package software
Current needs
Energy monitoring,
Energy savings and power
saving control,
Centralized management
of equipment monitoring
Ease and scalability of
monitoring
Diversity of equipment
monitoring
New needs
Fig.1 Status of power distribution monitoring
115
Special high-voltage,
high-voltage
incoming panel
High-voltage
feeder panel
Digital multi-function relay
(high-voltage protective relay)
F-MPC60B/ 50 Series
Igr insulation
monitoring device
F-MPC Igr
Low-voltage
feeder panel
Integrated-type power
distribution monitoring unit
(ground fault protection)
F-MPC04
Distribution
board
Multi-circuit type power
monitoring unit
F-MPC04P
Single-circuit type power
monitoring unit
F-MPC04S
Utility
(water, gas)
Digital input/ output
F-MPC I/ O unit
Single-circuit type AC
power monitoring unit
F-MPC04E
Fig.2 Application configuration diagram of “F-MPC Series”
electric power measuring unit, which accommodates
the marketplace desire for a low-price measuring device, and the “F-MPC I / O” digital input-output unit,
which facilitates the configuration of an energy control
system. Additionally, as a facility monitoring device,
Fuji Electric developed the “F-MPC Igr” insulation
monitoring device which automates insulation monitoring and is highly compatible with the F-MPC Series
of energy monitoring systems. Thus, in high-voltage
through low-voltage power distribution systems, these
F-MPC Series devices can be used to monitor the energy and facility status centrally using a common communication network.
3. Electric power Measuring Device Used in
Distribution Panel Inside
As an addition to the “F-MPC04 Series” lineup of
electric power measuring units, Fuji Electric developed a compact model, the F-MPC04E, which can be
installed easily in an existing distribution panel. The
F-MPC04E is a single-circuit type AC power monitoring unit that can be installed easily in a panel by
rail-mounting. With a RS-485 communication interface provided as a standard feature, this unit can
collect measured electric power values via a communication line, and is well suited for use as a power
measuring terminal in an energy monitoring system.
Additionally, a dedicated display is available as an option so that the measured values can be checked on a
display panel. Figure 3 shows the external appearance
of the single-circuit type AC power monitoring unit.
Since the required accuracy for energy monitoring with the F-MPC04E, as same as existing models,
is equivalent to the ordinary class specified in JIS,
the F-MPC04E is better suited for more economic sys-
116
(a) Single-circuit type AC power
monitoring unit
(DIN rail mounting)
(b) Optional display
(panel mounting)
Fig.3 Single-circuit type AC power monitoring unit
tems than those existing models. Additionally, setting
of the applied current transformer (only for F-MPC
dedicated type) and the communication address can be
carried out simply by switch operations on the main
unit. Consequently, the configuration settings can be
implemented easily, without having to connect and
energize a display at the time of installation work. As
for the measurement of electric power, in a distribution
system in which an energy-creating equipment such as
a photovoltaic power station is installed, the reverse
power flow can be measured and the integrated watt
hour value can be recorded in the forward and reverse
directions. The F-MPC04E has the following characteristics.
™Size: H80 × W55 × D58 (mm) (1/ 2 size of prior
model)
™Mass: Approx. 120 g (1 / 3 mass of prior model)
™Phase and wire system: Single-phase 2-wire,
single-phase 3-wire, 3-phase 3-wire (automatic
identification)
™Accuracy of the power monitoring: Equivalent to
ordinary class specified in JIS
™Communication function: Selectable as either
Fuji Electric’s F-MPC-Net protocol or generalpurpose Modbus/ RTU
™Measurement function: Maximum current, average current, minimum current
Maximum current, average current, and minimum
current data that are useful in facility management
are calculated as root mean square (RMS) values per
commercial frequency cycle, and are updated every
minute. The latest data is held for 1 minute in the
F-MPC04E so that the status of peak current or the
like can be managed easily even with a RS-485 lowspeed measurement communication line.
Previously, in order to measure the constantly
fluctuating inrush current and the like in machinery,
instantaneous (waveform) values had to be recorded
using an expensive wave recording device. Even with
such a recording device, however, data could not be recorded and monitored continuously and permanently,
and it was difficult to constantly monitor the operating
status of the facility.
For example, in a production line that uses arc
Vol. 58 No. 3 FUJI ELECTRIC REVIEW
Pulse detector
F-MPC04E
Internet
Current trend graph
Average current
Min. current
Measurement of max.
and min.
RMS values per cycle
Monitoring of fluctuations
in peak current
Data collected in
1-minute intervals
Fig.4 System configuration example of fluctuation monitoring
in peak current
welding equipment, the value of the arc current is an
example of data that is useful for facility management.
Because the interval during which arc current flows is
extremely short and only lasts for several cycles, it was
difficult to manage the arc current with a general-purpose power monitoring system. By using this function
of the “F-MPC04E”, however, the RMS values of arc
current can be recorded and continuously monitored
with ease, and can be used as facility management
data. Figure 4 shows a system configuration example
of the fluctuation monitoring in peak current.
Demand monitoring
5
48
SR
Stacking
indicator
lamp
Usage monitoring
Distinctive Technologies of Latest Devices
Average
Min.
Max. current
F-MPC Web
Modem/ router
unit
Watthour
meter
Eth
ern
et
Max. (peak current)
1 minute
F-MPC I/ O unit
Fig.5 Example of demand monitoring
Target and
3 level
monitoring
3 level of
alarm can be
set
Actual and
estimated value
4. I / O Unit Optimally Suited for Energy
Monitoring
Fig.6 Demand monitoring screen
Since the Great East Japan Earthquake, there has
been concern about a supply shortage of electric power,
and the purpose of energy monitoring has shifted to
peak shaving of instantaneous power. If Japan faces
a heat wave in the summer of 2012, a shortage of approximately 10% in peak power throughout Japan is
predicted, and ongoing peak shaving should be continued. For this reason, specific measures must be undertaken in a timely manner as the next step after energy
visualization. Aiming to facilitate the systematization
of such management functions, Fuji Electric developed
the “F-MPC I / O unit” that is optimally suited for use
in an F-MPC energy monitoring system. The F-MPC
I/ O unit has the following features.
™Number of inputs and outputs: 6 inputs, 4 outputs
™Size: H80 × W100 × D58 (mm), same as “F-MPC
Web unit”, can be installed in a thin-type distribution panel
™Communication function: Fuji Electric’s F-MPCNet protocol or general-purpose Modbus/ RTU
Combining the input and output functions of the
F-MPC I / O unit and the F-MPC Web unit facilitates
coordination for energy visualization with warning
alarms and the like.
Figure 5 shows an example of a demand monitoring and alarm system. A single F-MPC Web unit is
able to support the demand monitoring of two sites.
The F-MPC Web unit sends an alarm message via an
Intranet or the Internet when the expected value of
electric power is near exceeding a preset alarm level.
The F-MPC I / O unit has six digital inputs, two of
which are for receiving electric power pulses, and four
digital outputs, all of which are relay outputs capable
of directly driving a lamp or a buzzer.
In the example of this system, the F-MPC I/O
unit counts received power pulses, and the F-MPC
Web unit, using a demand monitoring function that
estimates the peak power every 30 minutes, issues an
alarm by email and by relay output when the target
peak power is near to be exceeded. Figure 6 shows a
demand monitoring screen of the F-MPC Web unit.
Three level of alarm can be set for the target peak power, and because F-MPC04 Series measuring equipment
can easily be connected to the RS-485 communication
line of the F-MPC Web unit for data collection, the system can be expanded to a more detailed power monitoring system. In this case, an alarm can be output
detecting the instantaneous power exceeding with the
alarm setting of the F-MPC Web unit, and peak shaving can be realized toward a power-saving target.
Moreover, since the F-MPC I / O unit can count
power pulses from a watthour meter for power management, pulses from water and gas meters, and pulses from calorimeters, as well as input power pulses, it
can comprehensively manage other utility in addition
to electricity.
Devices for Facility and Energy Monitoring Systems –Expansion of “F-MPC Series”–
117
5. Insulation Monitoring Unit for Equipment in a
Live State
In accordance with Japan’s “Electricity Business
Act,” insulation resistance must be measured periodically during power outages as part of the insulation
management for low-voltage electrical circuits. For
the general measurement of insulation resistance, a
facility is required to stop temporarily and then a DC
voltage is applied to measure the insulation resistance.
The types of loads which cannot be measured with this
method, however, are increasing year-by-year. In addition, there are problems such as not knowing the
extent of insulation degradation while the facility is
operating. Therefore, a function capable of continuous
monitoring of the insulation condition during operation
of the facility has attracted considerable attention.
According to the Japanese “Safety regulations of
electric facilities for private use” that prescribe management of the insulation condition at a facility, by
installing a monitoring device that continuously monitors the insulation condition online and outputs an
alarm when the insulation condition exceeds a certain
level, the inspection cycle can be extended from once a
month to once every other month. At facilities such as
data centers and semiconductor factories which operate 24-hours a day, the facility status can be monitored
during operation, thus enabling prevention of unexpected power outages during operation and fewer pow-
Table 1 Comparison of insulation monitoring methods
Item
Io method
Ior method
Igr method
All lowvoltage
circuits
Singlephase
3-wire,
3-phase
3-wire
delta
All lowvoltage
circuits
Effect of
high harmonics
There is an
effect
No effect
No effect
Effect of
electrostatic capacitance
to ground
There is an
effect
No effect if no
imbalance
among
phases
No effect
Detection
of ground
phase
Not
possible
Not
possible
Possible
Magnitude
of leakage
current
Resistance
component
within
leakage
current
Resistance
component
of superposed lowfrequency
components
Measuring
device +
ZCT
Measuring
device +
ZCT
Measuring
device +
ZCT + injection device
+ injection
transformer
Applicable circuits
Detection
function
Detected components
System configuration
Installation cost
118
Low
Medium
High
er shutdowns for inspections, and therefore, there is
increasing demand for an insulation monitoring device
that has this type of function.
There are two methods of insulation monitoring,
an Igr method which superposes the signal waveform
being monitored, and an Ior method which uses the
line voltage as a reference. Either of these monitoring
methods can be used to manage the insulation condition by removing the higher harmonics contained in
the earth leakage current, excluding the earth leakage
current due to capacitive components of the cable and
the load, and accurately detecting the earth leakage
current of the resistance component only. In particular, because the Igr method can be applied to any type
of line, can be used to monitor a grounding line and is
unaffected by the imbalance among phases in the electrostatic capacitance to ground, the Igr method is superior to the Ior method.
For the F-MPC Series of power monitoring equipment, Fuji Electric developed the F-MPC Igr as an
insulation monitoring device that uses the Igr method
of superposing the monitoring waveform. Thus, to a
conventional power monitoring system, by adding a
function for monitoring the insulation state of a facility
with the F-MPC Igr, a system can be provided that is
capable of simultaneously monitoring both the energy
usage status and the insulation status. Table 1 compares the insulation monitoring methods.
(1) F-MPC Igr configuration
The F-MPC Igr consists of an injection device and
an injection transformer to superpose the waveform for
monitoring, and a zero phase sequence current transformer (ZCT) and measuring device to measure the
current of each circuit (see Fig. 7). The measuring device is configured from a storage case for 4 or 8 circuits,
a measuring unit for each circuit, and a base unit for
collectively setting data to the measuring units and
for displaying data. The conversion from high-voltage
to low-voltage is performed by multiple transformers, such as a 3-phase transformer for motor use and
single-phase transform for lamp use in a single highvoltage distribution system, and therefore the storage
case is selected according to the applied system.
ZCT
Injection
transformer
Injection
device
Measurement
unit
B-class ground
Base unit
Storage case
Measuring device
Fig.7 “F-MPC Igr” configuration
Vol. 58 No. 3 FUJI ELECTRIC REVIEW
Item
Specification
Superposed
frequency
Superposed
voltage
Injection
transformer
10 / 7.5 / 6.3 V (linked to frequency)
20 / 15 / 12.5 Hz
30 mm φ, 20 turns
ZCT
30 mm φ, 1,000 turns
Control power
supply
85 to 264 V AC
Measurement
function
Leakage current: Io / Iob
Resistive leakage current: Igr
Capacitance to ground: C
Alarm
function
Io / Iob alarm: 0.1 to 3 A, 0.1 to 120 s
Igr caution alarm: 5 to 75 mA, 40 s
Igr warning alarm: 10 to 200 mA, 10 s
Selfdiagnostic
function
ZCT connection check function
Frequency setting consistency check function
Insulation monitoring accuracy check function
(2) F-MPC Igr specifications
Table 2 lists the specifications of the F-MPC Igr.
The superposed waveform for monitoring has a minute voltage of 0.5 V or less, and is sufficiently small
compared to the voltage of a commercial power supply. Minute earth leakage currents flowing in a circuit
are detected with this monitoring waveform, and the
F-MPC Igr unit converts the detected values to the
voltage level of the applied system to display and monitor those values.
Applied circuit voltages are supported from a mini-
mum of 90 V to a maximum of 440 V in accordance
with the distribution system of the manufacturing facility or building.
Utilizing a communication network, centralized
monitoring can be performed using Fuji Electric’s
“F-MPC-Net Web” power monitoring package software
or the like. Moreover, in consideration of stand-alone
usage, an alarm output contact is provided for devices
collectively and for individual circuits, and the unit
is capable of recording the alarm history with a timestamp for the previous 10 alarm occurrences.
6. Postscript
The “F-MPC Series” of devices for energy monitoring systems supports not only small-scale facilities, but
also has superior expandability for supporting medium-scale to large-scale monitoring systems.
The devices introduced herein enable reductions in
system cost, facilitate support of warning alarms that
lead to energy savings and power cutting down as a
next step after visualization, and enable systems to be
expanded for facility monitoring.
While continuing to leverage the merits of these
advantages, Fuji Electric intends to promote the expansion of systems and devices capable of making positive contributions to energy savings and power cutting
down policies, and to contribute to measures for reducing energy consumption by the customers, leading to
improvement of the global environment.
Devices for Facility and Energy Monitoring Systems –Expansion of “F-MPC Series”–
119
Distinctive Technologies of Latest Devices
Table 2 “F-MPC Igr” specifications
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