ABB ACS850 series User guide

ACS850
Common DC configuration application guide

ACS850
Common DC configuration application guide
3AUA0000073108 REV A EN
EFFECTIVE: 22.3.2010
©2010 ABB Oy. All rights reserved.

5
Safety instructions
Chapter overview
WARNING! All electrical installation and maintenance work on the drive should
be carried out by qualified electricians only.
Never work on the drive, the braking chopper circuit, the motor cable, or the motor
when input power is applied to the drive. After disconnecting the input power, always
wait for 5 minutes to let the intermediate circuit capacitors discharge before you start
working on the drive, control cabling, motor, or motor cable. Even when input power is
not applied to the drive, externally supplied control circuits may carry dangerous
voltages. Always ensure by measuring that there is no voltage in the drive, control
cabling, motor, or motor cable you are working with.
A rotating permanent magnet motor can generate a dangerous voltage. Lock the motor
shaft mechanically before connecting a permanent magnet motor to the drive and
before doing any work on the drive system connected to the permanent magnet motor.
For complete safety instructions, see the relevant drive manual. See Drive modules
documentation for a list of drive hardware manuals.
Safety instructions

6
Safety instructions

7
Table of contents
Safety instructions................................................................................................................................. 5
Chapter overview ..................................................................................................................................... 5
Table of contents.................................................................................................................................... 7
Introduction to the manual.................................................................................................................. 10
Compatibility........................................................................................................................................... 10
Intended audience.................................................................................................................................. 10
Categorization according to the frame size ............................................................................................ 10
Drive modules documentation................................................................................................................ 10
Common DC configurations................................................................................................................ 12
Introduction............................................................................................................................................. 12
Configuration steps ................................................................................................................................ 13
Common DC configuration.................................................................................................................. 15
Power ratings for DC connection............................................................................................................ 15
Average rectifier power Prec,ave ...................................................................................................... 15
Peak rectifier power Prec,max........................................................................................................... 15
Chokes, braking choppers and charging circuits.................................................................................... 16
Power requirements ............................................................................................................................... 16
DC link power Pdc,mot of motoring axis ........................................................................................... 17
DC link power Pdc,gen of regenerating axis..................................................................................... 17
Average motoring power Pmot,ave ................................................................................................... 18
Peak motoring power Pmot,max ........................................................................................................ 18
Average regenerative power Pgen,ave ............................................................................................. 18
Peak regenerative power Pgen,max .................................................................................................. 18
Supply unit selection .............................................................................................................................. 19
DC link power supplied via the drive.................................................................................................. 19
Single AC input (frames A…D) ..................................................................................................... 19
Single AC input frames E0…G...................................................................................................... 19
Multiple AC input........................................................................................................................... 19
Checking the charging capacity......................................................................................................... 21
Single AC input ............................................................................................................................. 21
Multiple AC input........................................................................................................................... 22
Charging current ........................................................................................................................... 22
Frame sizes A…D......................................................................................................................... 23
Frame sizes E0, E and G.............................................................................................................. 23
Table of contents

8
External DC supply ............................................................................................................................ 24
Frame sizes A…D ......................................................................................................................... 25
Frame sizes E0, E and G .............................................................................................................. 25
Supply units other than ACS850 ................................................................................................... 25
Mains choke selection ............................................................................................................................ 25
Mains choke data............................................................................................................................... 26
Single AC input .................................................................................................................................. 26
Multiple AC input................................................................................................................................ 26
Harmonic distortion............................................................................................................................ 27
Regenerative power ............................................................................................................................... 27
Common DC capacitance.................................................................................................................. 28
DC link capacitance ...................................................................................................................... 28
Energy capacity in common DC....................................................................................................28
Resistor braking................................................................................................................................. 29
Braking power ratings ................................................................................................................... 30
Single braking chopper ................................................................................................................. 30
Multiple braking choppers ............................................................................................................. 31
Braking resistor selection .............................................................................................................. 31
Single braking resistor................................................................................................................... 31
Multiple braking resistors .............................................................................................................. 31
Braking resistor types.................................................................................................................... 32
General system design items ................................................................................................................. 32
Fuse protection .................................................................................................................................. 32
Selection of AC supply fuses ........................................................................................................ 33
Selection of DC connection fuses ................................................................................................. 33
EMC................................................................................................................................................... 34
Installation.......................................................................................................................................... 34
Supply................................................................................................................................................ 34
Phase loss guard ............................................................................................................................... 34
Cables................................................................................................................................................ 35
Contactors, DC bus and brake circuit ................................................................................................ 35
READY signals .................................................................................................................................. 35
Drive module settings ........................................................................................................................ 36
General technical data....................................................................................................................... 37
DC voltage limits ........................................................................................................................... 37
Powering the AC fan in frame G ........................................................................................................ 38
Table of contents

9
Table of contents

10
Introduction to the manual
This chapter describes the intended audience and contents of this manual. It contains
a flowchart of the steps for configuring the common DC system. The flowchart refers to
the chapters and sections in this manual and in other manuals.
Compatibility
This manual is compatible with ACS850-04 drive modules and the related options.
Intended audience
This manual is intended for people who plan the installation, install, commission, use,
and service the drive modules connected in the common DC link. Read the drive
hardware manual before working on the drive. The reader is expected to know the
fundamentals of electricity, wiring, electrical components, and electrical schematic
symbols. This manual is written for readers worldwide. Both SI and imperial units are
shown wherever appropriate.
Categorization according to the frame size
Some instructions, technical data, and dimensional drawings that only concern certain
frame sizes are marked with the symbol of the frame size. The frame size is marked on
the drive and in the rating tables in the related hardware manuals.
Drive modules documentation
This guide contains only common DC related technical items for the ACS850 drive
modules. For complete documentation, see the table below. If there are deviations in
the given data between this guide and other manuals, then the document with the
latest date (Effective: xx.yy.20zz) will apply.
Manual Code (English)
ACS850-04 Drive Modules (1.1 to 45 kW) Hardware Manual 3AUA0000045496
ACS850-04 Drive Modules (55 to 160 kW, 75 to 200 hp) Hardware Manual 3AUA0000045487
ACS850-04 Drive Modules (200 to 500 kW, 250 to 600 hp) Hardware Manual 3AUA0000026234
Introduction to the manual

11
Introduction to the manual

12
Common DC configurations
Introduction
Drive modules can be connected together via DC terminals to have a so called
common DC configuration. Within common DC, the drives with regenerative power
from the motor can via DC link feed the other drives that are on the motoring mode.
The major benefits with this kind of connection are the following:
•Energy saving due to a reduced need for the supply side power. In optimum case,
there is also no need for braking resistors if the simultaneous regenerative power is
not higher than the motoring power.
•A DC link energy storage can be used for short dynamic braking energy pulses to
avoid the need for an external braking resistor.
•Braking energy can be handled with one unit even if several drives are in the
regenerative mode at the same time. However, several units with an active braking
chopper can be used simultaneously with the braking resistor if needed.
•Possibility for one AC input connection. The selected unit, in addition to its own axis
power, feeds also other drives connected to the common DC.
MM M M
~~~~~~~~
Sample
configuration 1
Common DC configurations

13
M M M
~ ~ ~~~~~
Sample
configuration 2
Unequal current distribution and different charging methods cause difficulties to
common DC systems:
•Unequal current distribution is influenced by input cables, AC or DC chokes and
input bridges’ forward characteristics. If the voltage reduction over the supply
components mentioned is not the same with all converters, more current will flow
through the converter which has a lower voltage reduction. Factors which influence
the current distribution include temperature, tolerances of components and in DC
choke cases the input cable’s cross-sectional area and length.
•Charging methods vary depending on the converter size. Because of this in some
installations, the supplies of the frame sizes A-D should be disconnected when they
are connected parallel with frame sizes E0, E and G.
Note: The drive compliance with the EMC Directive on low voltage networks is
specified in the appropriate Hardware Manual. However, please notice that different
common DC configurations have not been tested according to the EMC requirements
of conducted and radiated emissions.
Configuration steps
Here is a simple flowchart for configuring a common DC system. Each configuration
step is described in more detail in the related sections.
Common DC configurations

14
Configuration step Related section
If the input terminals of frame size G are
left unconnected, make sure that the AC
fans are powered separately.
General system design (fuses, EMC,
installation, etc.)
•energy capacity in the DC link
•resistor braking
Regenerative power handling
•harmonic distortion (THD)
•AC input current
Select the mains choke(s) if necessary
•charging capacity
•multiple AC input
•single AC input
Select the drive module(s) to be
connected to the AC supply
•average and maximum total
regenerative power
•average and maximum total
motoring power
•DC link power versus time for
each axis
Define the common DC power profile
Power requirements
Supply unit selection
Mains choke selection
Regenerative power
General system design items
Powering the AC fan in frame G
Common DC configurations

15
Common DC configuration
Power ratings for DC connection
The power unit diagram with related power ratings is shown in the following figure.
~~
~~
U2
W2
V2
U2
W2
V2
UDC+ UDC-
Frames A, B, C and D
Frames E0, E and G
UDC+ UDC-
U1
V1
W1
U1
V1
W1
Prec
,
ave
Average rectifier power Prec,ave
Prec,ave is the maximum average DC power that the input bridge of a drive can supply.
The actual average DC power taken from the input bridge should be lower than this
value in any 3 minutes time window.
Peak rectifier power Prec,max
Prec,max is the maximum short time DC power capacity of a drive. This is the maximum
DC power level for the input bridge and the DC connection terminals during 1 s.
Common DC configurations

16
Prec,ave P
rec,maxACS850 Type kW kW
03A0-5, 03A6-5, 04A8-5, 06A0-5 3.5 4.4
08A0-5 4.7 5.9
010A-5 6.5 8.1
014A-5, 018A-5 10.8 13.5
025A-5, 030A-5, 035A-5 20.5 25.7
044A-5, 050A-5 29.2 36.5
061A-5, 078A-5, 094A-5 52.9 66.2
103A-5 61.0 77.1
144A-5 85.3 90.1
166A-5 98.2 103.6
202A-5 119.3 133.9
225A-5 133.3 154.8
260A-5 152.2 197.3
290A-5 171.7 215.4
430A-5 260.2 315.6
521A-5 315.3 351.3
602A-5 364.5 442.8
693A-5 419.5 511.2
720A-5 435.7 511.2
Prec values are defined at 540 V DC link voltage level, which corresponds to the
nominal 400 V AC supply voltage Uac. In case of other DC voltage levels (Udc), the Prec
values in the table are multiplied by Udc /540 where acdc U.U
×
≈
351 .
Chokes, braking choppers and charging circuits
Drive Frame Choke Braking
chopper DC supply charging circuit
A, B - As standard Built-in
C, D DC As standard Built-in
ACS850
E0, E, G AC Optional External
Power requirements
In a common DC system, several drive modules are connected to the DC link. Each
drive and motor has its own specific load cycle profile. The sum of these load cycles
defines the system power profile in the DC link as shown in the figure below.
Common DC configurations

17
Common DC configurations
DC link power Pdc,mot of motoring axis
Pdc,mot is the power supplied to the DC terminals to get the required mechanical
motoring power on the motor shaft. Pdc,mot is higher than the shaft power, because it
also covers the losses in the drive and motor.
Pdc : DC link power
keff : efficiency factor (1/eff) to include drive and motor losses. If not known, value
1.25 can be used.
Pm: motor mechanical shaft power
T: torque (Nm) on motor shaft
n: motor shaft speed (rpm)
DC link power Pdc,gen of regenerating axis
Pdc,gen is now the power supplied from the regenerating motor to the DC terminals.
Pdc,gen is lower than the shaft power, because the shaft power now covers also the
losses in the drive and motor.
Based on the system power profile, the following system level DC link power values
are defined.
Drive
A
Drive
B
Drive
C
M M M
Pdc,mot
Drive losses
Motor losses
Pm
meffmot,dc PkP
×
=
9550
nT
)kW(Pm
×
≈
Pm
Drive losses
Motor losses
Pdc,gen eff
m
gen,dc k
P
P×=

18
Average motoring power Pmot,ave
Pmot,ave is the average of the motoring DC link power over the whole cycle. This power
is taken from the AC supply. For long load cycles, Pmot,ave should be determined over
the worst-case 3 minutes time window.
Peak motoring power Pmot,max
Pmot,max is the positive peak power in the power profile. This value can have a major
impact on the selection of the drive module(s) connected to the AC supply if many axes
are accelerated simultaneously.
Average regenerative power Pgen,ave
Pgen,ave is the average of the regenerating DC link power over the whole cycle. This
power must be dissipated in the braking resistor(s) or fed back to the AC supply.
Pgen,ave should be determined over the worst-case 30 seconds time window if the
internal braking chopper of the drive is used.
Peak regenerative power Pgen,max
Pgen,max is the negative peak power in the power profile. This value has a major impact
on the number of active braking choppers needed.
The power values defined above are shown in the following diagram.
~
= ~
=
~
=
~
=
~
=
Pdc1
M1
M2
M3
Mn
R2
R3
Braking
resistor(s)
System power profile
Pmot,ave
Pmot,max
Pgen,ave
Pgen,max
Pdc
2
Pdc
3
Pdcn
Common DC configurations

19
Supply unit selection
DC link power supplied via the drive
The DC link power can be supplied via a suitable drive module for the common DC
system. The drive module will be selected based on Pmot,ave and Pmot,max requirements,
and charging circuit capacity requirements. In frames E0, E and G the charging circuit
of the connected module must be able to withstand the total charging energy Etot.
Single AC input (frames A…D)
In the optimum situation, only one drive module is connected to the AC supply and the
other drive modules are supplied via DC link. The following conditions must be fulfilled:
•Pmot,ave < Prec,ave
•Pmot,max < Prec,max
If the conditions cannot be fulfilled, either a drive module with higher Prec ratings can be
selected (if feasible) or a multiple AC input configuration can be used.
Single AC input frames E0…G
To determine whether it is possible to leave other converters unconnected to the main
supply see chapter Checking the charging circuit capacity. The following conditions
must also be fulfilled:
•Pmot,ave < Prec,ave
•Pmot,max < Prec,max
•Etot < Erconnected
Multiple AC input
To determine whether it is possible to leave some converters unconnected to the main
supply see chapter Checking the charging circuit capacity.
If two or more drive modules are connected to the AC supply, the same conditions as
above must still be fulfilled:
•Pmot,ave < Prec,ave
•Pmot,max < Prec,max
•Etot < Erconnected
Where Prec ratings are now calculated from the individual ratings as follows:
•Prec,ave = Prec,ave1 + k(Prec,ave2 + Prec,ave3 +…. )
•Prec,max = Prec,max1 + 0.9k(Prec,max2 + Prec,max3 +…. )
Prec,ave1 and Prec,max1 are are the values of the drive module with the highest power
ratings. It is recommended that the parallel connected units are the same size.
Common DC configurations

20
Only converters that are connected to the main supply, are used for the power limit
calculations. The power correction factor, k, for each combination can be found from
Table 1. When several converters are connected to the main supply, the least efficient
power correction factor is chosen from table 1, i.e. the smallest factor. See Example1
and Example2.
When the charging circuits of the converters are different, this connection is not always
allowed. The table below shows when the connection cannot be used.
ACS850 power correction factors
Frame size A, B C, D E0 or E G
A, B k=0.8 No k=0.6 C k=0.6 C
C, D No k=0.5 No No
E0 or E k=0.6 C No k=0.7 k=0.6
G k=0.6 C No k=0.6 k=0.7
No: Do not connect the supply of the smaller converter. The converters have different types of input
chokes. Frame sizes C and D have DC chokes and frame sizes E0-G have AC chokes.
C: If both converters are connected to the main supply, the DC links must be connected together via a
contactor because the converters have different charging circuits. The DC contactors are switched on after
all of the DC links are charged and the converters are in the READY state.
Note: The Prec.ave value is higher if the smallest converter is not connected to the main
supply.
Example 1
The DC buses of three converters ACS850-04-08A0-5, 4.7 kW, (A); ACS850-04-035A-
5, 20.5 kW, (C) and ACS850-04-035A-5, 20.5 kW, (C) are connected together. The
input terminals of the 3 kW converter are left unconnected. k = 0.5 when two frame C´s
are connected to the main supply, therefore Prec,ave is
Prec,ave = 20.5kW + 0.5 · 20.5kW = 30.75 kW
Example 2
The DC buses of three converters ACS850-04-103A-5, 61 kW, (E0); ACS850-04-202A-
5, 119.3 kW, (E) and ACS850-04-521A-5, 315.3 kW, (G) are connected together. All
three converters are connected to the main supply. According to Table 1, k = 0.7 when
E0 and E are connected to the main supply and k = 0.6 when E and G are connected
to the main supply. The lowest factor is used in the calculations, i.e. k = 0.6, therefore
Prec.ave = 315.3 kW + 0.6 ·119.3 kW + 0.6 · 61 kW = 423.5 kW
Common DC configurations