TALLINN UNIVERSITY OF TECHNOLOGY Department of Electrical Drives and Power Electronics

Tanel Jalakas, Valery Vodovozov, Dmitri Vinnikov

ADVANCED COURSE ON POWER ELECTRONICS Laboratory works

Tallinn 2008

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Tanel Jalakas, Valery Vodovozov, Dmitri Vinnikov. Advanced Course on Power Electronics. Laboratory works Tallinn University of Technology Department of Electrical Drives and Power Electronics Tallinn, 2008 Preparation and publication of this study material was supported by SA Innove Tallinn University of Technology Department of Electrical Drives and Power Electronics Ehitajate tee 5, Tallinn 19086 Telefon 620 3700 Fax 620 3701 http://www.ene.ttu.ee/elektriajamid/ Cover designed by Ann Gornischeff Copyright: Tanel Jalakas, Valery Vodovozov, Dmitri Vinnikov, Tallinn University of Technology, Department of Electrical Drives and Power Electronics, 2008 ISBN 978-9985-59-792-7

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Contents 1. Introduction..................................................................................................... 5 2. Safety Warnings ............................................................................................. 5 3. Description of laboratory setup....................................................................... 5

3.1 General description....................................................................................5 3.2 ACS 800 frequency converter..................................................................10 3.3 Installation of ACS 800 frequency converter............................................16 3.4 ACS 800 protective circuits and selection of fuses ..................................16

4. Instructions of laboratory works.................................................................... 18 4.1 Work no. 1. Commissioning the Power Converter ...................................18 4.2 Work no. 2. Power Converter Characteristics ..........................................22 4.3 Work no. 3. Computer Examining of the Power Converter ......................24

5. Using digital oscilloscope TPS2000 series ................................................... 27 5.1 Viewing a Signal ......................................................................................27 5.2 Taking Quick Measurements ...................................................................27 5.3 Taking Cursor Measurements..................................................................27 5.4 Taking Automatic Measurements ............................................................28

6. Initial settings of ACS800 for laboratory works ............................................. 29 References ....................................................................................................... 30

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1. Introduction These regulations are intended for use as a tutorial aid to implement laboratory tasks in the framework of AAV0050 Advanced Course on Power Electronics. The student is expected to have acquired knowledge of electronic components, standard electrical wiring, and electrical schematic symbols. The brochure is in compliance with the curriculum and contents of “Advanced Course on Power Electronics”. A student should read and understand the safety warnings prior to starting working on the laboratory setup.

2. Safety Warnings 1. Always remember that the laboratory setup is a dangerous device. Never

apply the main power and never run the motor if it may cause danger or an injury.

2. Before powering the laboratory setup, make sure that all equipment and measuring instruments are suitable for operation throughout the speed, voltage, and current range provided by the drives.

3. To avoid electric shock, never open the covers and do not touch the cables or motors when the main power is applied or shafts rotate.

4. Do not control the motor by disconnecting the device; instead, use the control panel keys or console buttons.

5. Do not run the motor over the rated speed and do not allow their long-term overloading.

6. Remember that the STOP key on the control panel has no effect if the control location is not set to LOCAL; to stop the drive in this mode press the STOP button on the console.

7. Remember that pressing the STOP key or the STOP button neither causes an emergency braking of the motor nor instantly disconnects the drive from dangerous potential. Press the EMERGENCY switch on the console to stop the drive in danger.

8. Remember that the maximum allowed number of power-ups is 5 in 10 minutes; exceeding this may damage the capacitors and switching devices.

3. Description of laboratory setup

3.1 General description The laboratory setup includes two motor drives ACS800 series: the testing drive and the loading drive. Each drive has the same structure, consisting of:

• induction motor, • power converter, • remote console, • cabinet, housing, • measuring, and cabling equipment.

The motor shafts of the drives are mechanically coupled to each other to provide joint rotation. Both power converters are wall-mountable low-harmonic units supplying the motors. Each includes the line-side active rectifier and the motor-side inverter connected via the dc link.

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M

Figure 1. Principal schematics of a converter

A typical converter cabinet contains:

• power converter, • cooling fan under the top cover, • control drive panel mounted on the front cover, • heat sink on the back side, • connection box under the bottom cover.

The main circuit diagram of a single motor drive is shown in Fig. 1. Each converter involves two modules coupled via a dc link. Both the line-side rectifier and the motor-side inverter have six IGBTs with freewheeling diodes. In the motoring mode, the line-side rectifier passes the three-phase ac voltage into the intermediate dc link, which further supplies the motor-side inverter running the motor. Instead, in the braking mode, the motor-side inverter passes energy back from the motor to the supply lines through the dc link and the line-side rectifier. The line filter suppresses the voltage and current harmonics. Electrolytic capacitors in the dc link serve for energy buffering. By default, the converter dc link voltage reaches the peak value of the line-to-line voltage and if necessary can be set also higher. The IGBT gating is based on the space vector modulation principle further used for the scalar converter adjustment or direct torque control (DTC). To calculate the switch turn on/off instants and fault protection, the line currents and the dc link voltage are measured automatically by the converter sensors.

Figure 2. Principal schematics of a drive

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There are three sources for the drive control:

• REM – remote (external) control from the console coupled via input/output connections (I/O) or fieldbus interface,

• LOC [1] – local control from the control panel, • LOC [2] – local control from the computer DriveWindow software.

Each source provides a user interface both the line-side and motor-side modules with essential controls and parameter settings for the application programs. In Fig 2. a simplified block diagram of the drive system is shown. Some control options enable connection of an external user interface to the converter trough I/O or fieldbus. To conduct the measurements, on the external console there are some 4 mm laboratory sockets to connect the measuring devices to the converter. It is possible to measure input and output voltage and current and DC-link voltage. To ensure electric safety, a differential measuring amplifier with sufficient isolation voltage is always needed when connecting the oscilloscope to the converter. To control and set up the converter, are a fibre-optic cable and PC with installed DriveWindow program needed.

SAGEDUSMUUNDUR ACS800

Pealüliti Start StoppPöörlemis-

suund - Kiirus +

AvariiKaitseTöötabPingestatud Rike

L1

L2

L3

N

U

V

W

UDC+ UDC-PE PE N

Figure 3. ACS 800 laboratory setup

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Figure 4. External circuits

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Frequency converter is installed on the mobile metal frame. On that frame there are also the cabinet for control and protection devices and the external console (Fig. 3). On the cabinet door there is the remote console with control buttons for switching on and off the device, for reverse, for changing the speed, and for emergency shutdown. There are also the 4mm laboratory plugs for measuring device connection. In Fig. 5 the acquired output voltage and the current of the converter are shown. For quick shutdown of the converter emergency shutdown button is used. The converter will also shut down when the cabinet door is opened. NB! When using emergency shutdown, the device is switched off put the mechanical parts of the drive may still be moving for some time.

Figure 5. The PWM of output voltage and output current The metal shelf above the converter is meant for measuring devices. Do not cover the converter ventilation openings. Also, you must be careful not to drop any items (screwdrivers, wire ends, pens) into the opening of the ventilation system of the converter. The converter is connected with the load and the working machine through the plugs located at the back of the rack (Fig. 4). To provide a load to the converter, two mechanically coupled asynchronous motors are used (Fig. 6).

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ABB ACS 800

SAGEDUSMUUNDUR ACS800

Pealüliti Start StoppPöörlemis-

suund - Kiirus +

AvariiKaitseTöötabPingestatud Rike

L1

L2

L3

N

U

V

W

UDC+ UDC-PE PE N

PC(Drive windows)

ABB ACS 800

SAGEDUSMUUNDUR ACS800

Pealüliti Start StoppPöörlemis-

suund - Kiirus +

AvariiKaitseTöötabPingestatud Rike

L1

L2

L3

N

U

V

W

UDC+ UDC-PE PE N

Working machine Load machine

Speed sensor(encoder)

Clutch

Working machine converter

Load machine converter

Supply Supply

Figure 6. ACS 800 Laboratory stands with a working and loading machine Working motor:

• nominal power – 5.5 kW,

• nominal input voltage – 400 V,

• nominal input current – 11 A,

• optional sensors – (temperature sensor).

Loading motor:

• nominal power – 15 kW,

• nominal input voltage – 400 V,

• nominal input current – 29 A,

• optional sensors – temperature sensor, speed encoder.

3.2 ACS 800 frequency converter ACS 800 frequency converter is a middle-power class device with various control possibilities. ACS 800 converter enables direct torque control (DTC, Direct Torque Control). With the DTC a good starting moment and smooth operation are easily reached. The DTC enables precise control of the motor speed and torque. Also quick reaction to abrupt changes in the load is possible. Without direct measurement the motor speed (tachogenerator or encoder) it is possible to keep the speed in changing load conditions with a precision of 0.1 to 0.5 % of the nominal speed.

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Technical data of the ACS 800 frequency controller:

• input: 3-phase,

• input voltage 380 – 415 V ±10%,

• input frequency: 48 – 63Hz,

• output voltage: 0 – 415 V,

• output frequency: 8 – 300 Hz,

• output power: 75 kW,

• temperature range: –15 – +50 0C,

• allowed moisture: 5 – 95%.

ACS 800 series frequency converter supports macros, user defined and predefined macros with factory settings are used.

• Factory settings – can be used in most industrial applications, where

there are no special needs for drive control;

• Hand/Auto control – systems requiring manual control;

• PID control – systems with feedback;

• sequential control – sequential processes;

• torque control – processes, where the torque control is needed;

• user macro – user defined macro (user can save up to two macros).

ACS 800 software enables • drive speed regulation,

• precise torque control without speed feedback,

• certain drive speeds,

• controlled torque at zero speed,

• flux brake,

• optimization of flux,

• control of mechanical brake,

• programmable I/O,

• scalar control,

• torque control,

• PID algorithm,

• acceleration and deceleration ramps.

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The ACS 800 frequency converters have numerous predefined and user tunable protection functions. The protection functions are activated when one of the following situations occur:

• overvoltage,

• undervoltage,

• DC-link overvoltage,

• DC-link undervoltage,

• overcurrent in the output,

• output overload,

• motor overtemperature,

• motor phase loss,

• control panel loss,

• external fault,

• user defined voltage limit,

• user defined current limit,

• user defined load limit,

• critical speed range.

Special setting macros are used for centrifuges, mills, pumps, ventilators, cranes, textile machines etc. The converter can also act as a simple PLC to control some simple processes.

Electrical connection of ACS 800 frequency converter Frequency converter will be connected with the supply and the motor according to Fig. 7. The wires and cables must have sufficient cross-section to withstand the currents (Table 1).

Figure 7. Electrical connection of ACS series converters

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The cable between the converter and the motor must be shielded. The cables between the command elements and the converter must be twisted pair shielded. If the command cables and power cables are laid in same cable canals, then the command cable must have at least 230 V insulation. To connect the power cables first remove the cover from the underside of the converter and then remove the transparent plastic detail covering the terminals. The power cables are connected according to Figs. 7 and 8. Table 1. Cross sections of wires according to certain currents

Current (A) Cable (mm2) 14 3 x 1,5 20 3 x 2,5 27 3 x 4 34 3 x 6 47 3 x 10 62 3 x 16 79 3 x 25 98 3 x 35 119 3 x 50 153 3 x 70 186 3 x 95 215 3 x 120 249 3 x 150 284 3 x 185

Figure 7. shows a correctly realized cable connection for several types of converter cabinets

a) b)

Figure 8. The correct ACS 800 supply and motor cable connections (a. R4 type cabinet and b. R6 type cabinet)

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The low voltage inputs and outputs of the converter.

Analogue inputs • 2 programmable current inputs (measuring range 4 – 20 mA),

• 1 programmable voltage input (measuring range 2 – 10 V),

• resolution of analogue inputs: 12 bit.

Analogue outputs • 2 programmable current outputs (4 – 20 mA),

• resolution of analogue outputs: 10 bit.

Digital inputs • 6 digital inputs (24 V, current consumption 10 mA per input),

• reaction time 1mS.

Relay outputs • 3 programmable relay outputs (24 V, 8 A, 240 V, 0.4 A).

24 V power supply for auxiliary devices • 24V supply, maximum 250 mA.

The switches, potentiometers, signal lights and sensors are all connected to screw-terminal block X20 – X27. Those terminals are located under the front cover of the converter. The connection plan for control devices is shown in Fig. 9.

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Reference voltage -10 VDC, 1 kohm < RL

<10 kohm

Reference voltage -10 VDC, 1 kohm < RL

<10 kohm (speed)

Speed reference 0(2) ... 10 V, Rin >

By default not in use

By default not in use

AO1+ Motor speed 0(4)...20 mA 0...motor nominal.

AO1+ Output current 0(4)...20 mA 0...motori nominal.

Start/stopForwar/reverse

Not in use

Acceleration/decceleration

Constant speed select

Constant speed select

24V DC, 100mA maximum

Digital ground

Digital ground

Start interlock

Auxiliary voltage, 24V DC, 250mA maximum

Relay output („fault”)

Relay output („running”)

Relay output („ready”)

Speed

Figure 9. Connection of control and auxiliary signals

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3.3 Installation of ACS 800 frequency converter When installing ACS 800 wall mounted converters, it is necessary to leave sufficient distance between the device and the and the cabinet (at least 50 mm between two devices and 200 mm distance between the upper or the lower part of the device and the cabinet wall or other device. The air in the location of the converter can be at maximum 40 0C temperature. It is recommended to use covers or build canals for air to prevent the hot air getting into the cooling air intake of the converter (Fig 10).

Figure 10. Cooling air circulation in the device cabinet

3.4 ACS 800 protective circuits and selection of fuses To ensure the best protection it is recommended that the converter would be supplied through fuses or protective switches and the contactor for isolation from the supply network. In Fig. 11 the contacts of the thermal switch Θ of the external braking resistor are shown. The thermal switch of the motor and the emergency switch can be connected to same circuit. To protect the contacts of the relay output relays, it is recommended to use diodes with the dc current, as in the case of the ac current the varistors or RC circuits can be used. The fuse must be selected according to Table 2. The reaction time for fuses must be at a minimum of 0.5 s. For detailed instructions please read ACS 800 installation manual.

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K1

In

Out

L1 L2 L3

U1 V2 W3

Fuses

Θ Thermal switch

ACS 800

1 3 5

2 4 6

1

2

3

4

13

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Figure 11. Fuses and thermal switches

Table 2. Selection of mains cable fuses

Nominal current Fuse A A A2S V

4,7 10 483 5006,0 10 483 5007,9 10 483 50010 16 993 50013 16 993 50017 20 1620 50023 25 3100 50032 40 9140 50042 50 15400 50053 63 21300 50069 80 34500 50083 100 63600 500

100 125 103000 500

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4. Instructions of laboratory works

4.1 Work no. 1. Commissioning the Power Converter Objective: Commissioning is a system start-up that involves testing and adjusting to assure proper functioning and understanding the principle of operation. The work aim is to learn how to start, stop, change the rotation direction, adjust the converter from the console and the control panel, and perform several ways to take signal observation and measurement as well.

Remote control of the power converter from the console • Check the laboratory setup. Make sure that the loading drive is not

powered. • Learn about the console using Fig. 12 and familiarize yourself with the

control panel in Fig. 13. • Power on the testing drive using the Main switch. Obtain information from

the control panel: panel identification data, drive identification data, and actual signals.

• Press the ACT key on the control panel and explore the status row displayed there:

Table 3

Module ID Control status Direction Reference Drive status 1 – motor-side 2 – line-side

L – local non or R– remote

→ forward ← reverse

Hz V

I – running 0 – stopped

non – disabled

Figure 12. External control panel

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• Ensure the drive is in the remote control mode (no L visible in control status); otherwise, press LOC/REM key to change between the local and remote control mode.

• To run the motor, press the Start button on the console. To adjust the speed, turn the Speed reference knob. To change the direction of the motor shaft rotation, use the Reverse switch. To turn off the motor press the Stop button.

• Power off the laboratory setup.

Control of the power converter from the control panel • Ensure the laboratory setup is not powered and the motors do not rotate. • Observe the tested drive ratings before further work by reading and

recording the data from the converter and motor nameplates. • Power on the testing drive. • Ensure the motor-side inverter is currently being controlled; otherwise,

press the DRIVE and ENTER keys, scroll to ID number 1, and press the ENTER and ACT keys to verify the change.

• If a fault occurs during the control, display **FAULT** or **WARNING** by the ACT key, and press the RESET key.

• Learn about the following general parameter setting procedure of the control panel:

o to enter the Parameter Mode, press the PAR key o to scroll the parameter groups, press the PAGEUP and PAGEDN

keys o to scroll parameters within a group, use the UP and DOWN keys o to activate the setting of a new value, press the ENTER key o change the parameter value by the UP and DOWN keys or fast

change by the PAGEUP and PAGEDN keys o to fix your choice, press the ENTER key

• Follow this procedure, enter START-UP DATA (parameter group 99), then set

• given APPLICATION MACRO and MOTOR CONTROL MODE, and further enter the motor data from the motor nameplate: MOTOR NOMINAL VOLTAGE, CURRENT, FREQUENCY, SPEED, POWER.

• To change from Remote to Local control, press the LOC/REM key (L visible on the display).

• To set or change the frequency Reference, press the REF key, then press the UP/DOWN to slow reference change or the PGUP/PGDOWN keys to fast change. Press the ENTER key to save the new reference in the memory until the power switch-off or further changing.

• To run the motor, press the START key on the control panel. To change the motor direction of rotation, press the REVERSE or FORWARD key. To stop the motor press the STOP key.

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Figure 13. local control panel

Data observation from the control panel • Run the drive in the remote control mode to the given reference value. • Press the ACT key to enter the Actual Signals Mode (parameter group

01) where the LCD displays three signals at a time. In the table below, some possible signals are listed:

Table 4

Parameter Name Description 01.03 FREQUENC[Y] Inverter output frequency, Hz 01.04 CU[RRENT] Motor current, A 01.06 POWER Motor power, % of nominal 01.07 DC VOLTA[GE] Intermediate link voltage, VDC 01.08 MAINS VO[LTAGE] Supply rms voltage, V 01.09 MOTOR VO[LTAGE] Motor rms voltage, V 01.10 PP TEMPE[RATURE] Temperature of heat sink, C 01.37 MOTOR

TE[MPERATURE] Estimated motor temperature, C

• Read and record sequentially the motor-side inverter values from this list.

To change a signal, move the blinking cursor by the UP/DOWN keys and press the ENTER key in the selected row, then select an actual signal by the UP/DOWN keys and press the ENTER key again.

• To obtain the line-side rectifier values unacceptable in the motor-side wiring, press the DRIVE key, scroll to ID number 2, and press the ACT key. Using the preceding procedure, read and record the rectifier values according to the next table:

No Name Function 1 LCD Display, 4 lines 2 ACT Actual Signals Mode 3 PAR Parameter Mode 4 FUNC Function Mode 5 DRIVE Drive Selection Mode 6 PAGEUP Large step up 7 UP Small step up 8 ENTER Set the choice 9 PAGEDN Large step down

10 DOWN Small step down 11 LOC/REM Local/Remote control 12 RESET Fault reset 13 REF Reference setting 14 START Run the motor 15 FORWARD Forward direction 16 REVERSE Reverse direction 17 STOP Stop the motor

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Table 5

Parameter Name Description 01.05 FREQUENCY Line frequency, Hz 01.06 LINE CURRENT Line current, A 01.07 REACTIVE

POWER Reactive power, kVAr

01.08 POWER Line-side power, kW 01.09 POWER Input power, % of nominal 01.10 DC VOLTAGE Intermediate link voltage, VDC 01.11 MAINS VOLTAGE Supply rms voltage, V 01.27 COSFII Power factor

Taking measurements • Use the oscilloscope to view and measure ac voltages and currents

using three different ways. • Firstly, use the oscilloscope graticule to make a quick, visual estimate of

the waveform, count major and minor divisions, and calculate the peak-to-peak voltage. Then, record them and sketch the on-screen waveforms.

• Secondly, switch on the amplitude and time cursors, move them along the measured trace, read their numeric values from the display readouts, and record them.

• Thirdly, take automatic measurements of the data pointed in the above tables which are more accurate and then complete the two preceding ones.

• Attach the multimeter, measure, and record the same currents and voltages from its readouts.

• Stop and power off the drive.

Individual report contents • functional circuit and specification of the laboratory setup • converter and motor data, including the company, type, standard, degree

of protection as well as the electrical and mechanical ratings • data of measuring instruments in the same scope as above • given reference value of the testing drive • table of the signals measured using the control panel, oscilloscope, and

multimeter • scaled diagrams of the current and voltage waveforms sketched from the

oscilloscope traces • conclusions concerning the estimation, comparison, and explanation of

the results

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4.2 Work no. 2. Power Converter Characteristics Objective: Characteristics help to understand converter performance in the loading and adjusting processes. The aim is to observe and explain converter characteristics as well as to build the corresponding diagrams.

Voltage/frequency characteristics Voltage/frequency characteristic is the trace of a converter output voltage versus frequency. It shows the converter linearity and the frequency and voltage range. When operated above a motor field weakening point, the converter cannot reach the full required output voltage, thus reducing the load capacity.

• Power on the testing drive. Set the zero reference frequency and define the motor voltage, current, and power as the actual signals. Record the obtained frequency, voltage, and power into the protocol table.

• Run the drive. Smoothly changing the reference in the range 0–70 Hz, fill the measured values into the protocol again.

• Using the records, build the voltage/frequency and power/frequency diagram. Find the field weakening border and the maximum motor voltage in the diagram.

• Return the reference frequency to zero and stop the drive.

Critical speed control The critical speed functions are useful in applications where it is required to avoid certain motor speeds or speed bands because of mechanical resonance or supply oscillation problems.

• To activate the functions set the parameter 25.01 CRIT SPEED SELECT to ON.

• Define the minimum and maximum limits for the critical speed band by setting the parameters 25.02 CRIT SPEED 1 LOW and 25.03 CRIT SPEED 1 HIGH to a given values (10–40 and 60–90 Hz accordingly).

• Run the drive. Smoothly changing the reference in the range 0–70 Hz, fill the measured values into the protocol and build the voltage/frequency and power/frequency diagram. Show the critical speed band in the diagram.

• Return the reference frequency to zero, stop the drive, and set the parameter 25.01 to OFF.

IR-compensation When IR-compensation is activated, the converter gives extra voltage boost to the motor at low frequencies. It is useful in applications that require high breakaway torque. Since voltage cannot be fed to the converter at 0 Hz, full IR-compensation starts around the slip frequency.

• To define the relative output voltage boost at zero speed, set the parameter 26.03 IR-COMPENSATION to a given value (10–30% of the motor nominal voltage).

• Run the drive. Smoothly changing the reference in the range 0–70 Hz, fill the measured values into the protocol and build the voltage/frequency

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and power/frequency diagram again. Show the IR-compensation band in the diagram.

• To define a frequency at which the IR-compensation reaches full value, set the parameter 26.04 IR STEP-UP FREQ to a given value (5–25 Hz) and repeat the experiment. Show the new IR-compensation band in the diagram.

• Return the reference frequency and the parameters 26.03 and 26.04 to zero and stop the drive.

Output characteristics Output characteristics collect a set of dependences of a converter output voltage versus current. They describe the loading possibilities and steady properties of a converter.

• Run the testing drive to a given reference frequency (20–30 Hz). • Power on the loading drive, set the reference torque to zero, and run it. • Record the loading torque and testing frequency, voltage, current, and

power into the protocol table. • Smoothly raising the loading torque from zero to the nominal current of

the testing drive, fill the same measured values into the protocol again. Unload the drive. Using the records, build the output diagram for the given frequency.

• Set the other given reference frequency of the testing drive. Then, changing the loading torque from zero to the motor nominal current, fill the measured values into the protocol and build the output diagram for the new frequency. Further, repeat the experiment in the frequency range 0 to 70 Hz.

• Set the previous value of IR-compensation and repeat the experiment in the low-frequency region.

• Unload and remove IR-compensation, stop and power off the drives.

Individual report contents • tables and diagrams of voltage/frequency characteristics without and with

the critical speed bands and IR-compensation • tables and diagrams of output characteristics with IR-compensation band • conclusions concerning the estimation, comparison, and explanation of

the results

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4.3 Work no. 3. Computer Examining of the Power Converter Objective: To maintain and learn ABB drives, the DriveWindow soft tool is used. The aim is to master the converter remote control, its signal monitoring, working with parameters, and graphical trending.

Acquaintance with the user interface of DriveWindow The user interface shown in Fig. 14 includes handling of the standard Windows areas from the keyboard and mouse by user editing, moving, dragging, and resizing.

• Power on the testing drive. • Connect DriveWindow to the drive by choosing ABB SMP string in the

Select OPC Server dialog box. • Find the main parts of the user interface:

o title bar o menu bar o toolbars including Standard toolbar, Monitor toolbar, Logger

toolbar, and Drive panel at the bottom o status bar along the bottom o window area divided by four panels: Browse tree and Item sets on

top as well as Trend settings and Trend display below

Control of the drive To control the drive, either the Drive panel or the Drive menu can be used. The status bar describes user actions.

• Select the drive in the Browse tree panel. • Take the control by toggling the Take/Release Control button. • Examine the status image, name, and address of the currently controlled

drive.

Figure 14. User interface

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• Reset the fault and clear the fault logger if an error occurs. • Assign given reference frequency (30-70 Hz) into the edit field and click

the Set Reference button or press Enter to send it to the drive. • Run the drive, and then stop it. • Change the motor direction of rotation and run it again. • Execute the coast stop. • Release the control and ensure the drive is adjustable from the control

panel.

Monitoring of the drive acceleration Control monitoring can be executed using the Monitor toolbar or the Monitor menu. Monitor runs and collects data by reading cyclically the items from the drive in real time.

• Take the control. • To learn about the drive acceleration, choose Parameters in the Browse

tree panel and set the parameter 22.02 ACCEL TIME 1 to a given value (5–15 s) in the Item sets planel.

• In the Trend Settings planel, set X-Axis Length above the given acceleration time.

• To add the motor voltage, current, and frequency for monitoring, choose 01 ACTUAL SIGNALS in the Browse tree planel and drag the required strings into the Trend Settings planel. The numeric images appear in front of the added items. The Delete button lets to remove unnecessary items from monitoring.

• To start monitoring, click the Start or Continue Monitoring button in the Monitor toolbar and right away run the drive to the given reference frequency.

• Wait until the running comes to the end and press the Stop Monitoring button. Then stop the drive also.

• To scale the trends swing, use Adapt Y-Axis from the Axis submenu or Autoscale from the Scaling submenu of the Monitor menu.

• When viewing the stopped or paused trends, click the drawing area to display the graph cursor which measures the items.

Saving and analyzing the results There are several ways to save trends. The currently displayed trends can be saved from File menu into a DriveWindow graph file, exported to a text file, copied to the clipboard, or printed.

• To process the data, select Export in the Graph submenu and assign a name of the created .txt file. Later, open the file by Microsoft Excel, recalculate per-unit data into Volts, Amperes, and Hertz, and build the required diagrams.

• To save the trends for the work to proceed, select Save As command and name and comment the new .dwt file. Saved graphs are actually incomplete offline workspaces, which contain just enough information to restore the graphs in the trend display. In the future, by double clicking or selecting Open command in the Graph submenu the saved file may be restored.

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• To use the trends in other applications, first copy them into the clipboard using Copy Graph command in Edit menu and then paste in the required software.

• To print the trends when the current printer is unavailable, use Microsoft Office Document Image Writer.

• After successful saving the monitor can be cleared by the Clear button and the parameter 22.02 ACCEL TIME 1 returned to 3 s.

Individual report contents • scaled diagrams of voltage, current, and frequency timing traces • mutual voltage/frequency diagram built using the voltage and frequency

data • output voltage/current diagram built using the voltage and current data • conclusions concerning the estimation and explanation of the results

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5. Using digital oscilloscope TPS2000 series

5.1 Viewing a Signal To quickly display a signal of an unknown amplitude or frequency, follow these steps:

• Power on the oscilloscope. • To connect the probe, align the slot in the probe connector with the key

on the CH 1 BNC, push, and twist to the right to lock the probe in place. • Push the CH 1 MENU button. • Choose Probe.Voltage.Attenuation.500X and set the switch on the probe

to the same value. • Connect the Channel 1 probe tip to the signal and the reference lead to

the circuit reference point. • Push the AUTOSET button. • To view two signals, connect the second probe to CH 2 BNC and use the

CH 2 MENU button. The oscilloscope sets the vertical, horizontal, and triggering controls automatically.

5.2 Taking Quick Measurements To measure time and amplitude, follow these steps:

• Turn the SEC/DIV knob to display the starting edge of the waveform. • At the chosen channel, turn the VOLTS/DIV and VERTICAL POSITION

knobs to set the waveform amplitude to about five divisions. • Push the CH 1 MENU button. • Choose Volts/Div.Fine. • Turn the VOLTS/DIV knob to set the waveform amplitude to exactly five

divisions. • Turn the VERTICAL POSITION knob to center the waveform; position

the baseline of the waveform 2–3 divisions below the center graticule. Use readouts in the screen bottom area to know the vertical scale factors of the channels and the main time base setting.

5.3 Taking Cursor Measurements Cursors quickly take time and amplitude measurements on a waveform. To measure a time span, follow these steps:

• Push the CURSOR button to display the Cursor Menu. • Choose Type.Time. • Choose the channel, for example Source.CH1. • Choose the Cursor 1 option button to display the first cursor location. • Turn the multipurpose knob to change the cursor position. • Choose the Cursor 2 option button to display the second cursor location. • Turn the multipurpose knob to change the cursor position.

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• Time cursors display ∆t (time difference between the cursors), 1/∆t (frequency), ∆V (or ∆I, voltage/current difference), and the times at cursors relative to the trigger in the Display Menu.

To measure amplitude, follow these steps:

• If the Cursor Menu is not displayed, push the CURSOR button. • Choose Type.Amplitude. • Choose a channel if necessary. • Choose the Cursor 1 option button to display the first cursor location. • Turn the multipurpose knob to change the cursor position. • Choose the Cursor 2 option button to display the second cursor location. • Turn the multipurpose knob to change the cursor position.

Amplitude cursors display ∆V (or ∆I, voltage/current difference between the cursors), and the signal values in the Display Menu.

5.4 Taking Automatic Measurements There are eleven types of measurements available: Freq – frequency, Period – the time of the first cycle, Mean – the arithmetic mean amplitude over the entire period, Pk-Pk – the absolute difference between the maximum and minimum peaks of the waveform, Cyc RMS – rms value of the first complete cycle, Min and Max – the minimum and the maximum values of the last 2500 points, Rise Time and Fall Time – durations of the first rising and falling edges, Pos Width and Neg Width – the first positive and the first negative pulse widths at the waveform 50% level. The oscilloscope can display up to five measurements at a time. To take a measurement, follow these steps:

• Push the MEASURE button to see the Measure Menu. • Choose the channel, for example Source.CH1. • Push another option button and choose the measurement type, for

example, Type.Freq. • Push the Back option button to return to the Measure Menu and display

the selected measurement.

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6. Initial settings of ACS800 for laboratory works Table 6. Index Value 10.01 DI1,2 10.02 DI6,5 10.03 REQUEST 11.01 REF1(REF2*) 11.05 70 16.01 YES

Index Value 16.02 OPEN 20.01 –70 (–1500*) 20.02 70 (1500*) 22.02 3 25.01 OFF 25.02 0

Index Value 26.03 0 26.04 OFF 99.02 HAND/AUTO**

(T-CTRL*) 99.04 SCALAR 99.10 NO (ID MAGN*)

* Loading drive ** Application macro User 2

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References [1] ACS800-31 Drives hardware manual, ABB Inc, 2005 [2] ACS800 standard application program 7.x, Firmware manual, ABB Inc, 2005. [3] DriveWindow2 software manual, ABB Inc, 2006. [4] Tektronix TPS2000 series digital storage oscilloscope User manual, Tektronix, 2007.