Category Archives: Reactive Power

Dr. InPhase Edu Series – How to use Krykard ALM-32/33/35 to carry out Power Quality Study

Hello Everybody. This is Dr. InPhase!!! In this dual part series I’ve already presented How to use Fluke 434-Series II for carry out Power Quality Study. In second part I’m going to walk through on How to use Krykard ALM-33/32/35 for carrying out Power Quality Study to record and analyze various Power Quality factors like Harmonics, Unbalance, Power Factor and so on.

KRYKARD ALM 32/33/35

  • To measure and record RMS voltage, current, power parameters in an electrical network.
  • To record the variations (power parameters) in the electrical network.

BASIC OPERATIONS

– Press to power up or power down the Krykard ALM-32/33/35 Analyser. The home screen shows RMS waveform for voltage and current.

DATE AND TIME

  • In home screen Press Configuration Button
  • Select Date/Time in Configuration screen
  • Press Enter button
  • Make the changes in DATE & TIME by using Navigation keys & Press ENTER.
  • Press Return button after the changes are made.

LANGUAGES & PHASE COLORS

  1. Measuring results belongs to different phases are presented with individual colors. Every region in the world having different sets of color code for the Phase sequences.
  2. Here we proceed with Indian region.
  3. The following steps are configuring the Phase Colors as well as Languages also.

FOR LANGUAGE

  • Press Configuration button
  • In Configuration screen, each Function keys belongs to different language.
  • In this screen the selected Function key belongs to English language.
  • Krykard ALM-32/33/35 offers 26 regional languages along with English.

FOR PHASE COLOR

  • Press Configuration button and Select Display
  • Press 2nd Function key for the Colors option
  • In this screen, we can change the voltage, current color coding of Phase & Neutral as per the region by using of Navigation keys.
  • If we select 1st Function key, there will be an option for Brightness adjusting. Brightness can be adjusted as per the requirement using Navigation keys.

  • If we select 3rd Function key, an option for automatic Display shutdown. Select Never/Automatic as per the requirement.

  • If we select 4th Function key, an option for Night mode. Activate/Deactivate as per our requirement.

WIRING SYSTEM CONFIGURATION

  1. Krykard ALM-32/33/35 has a several preprogrammed wiring setup of electrical system/equipment.
  2. Based on the system configuration like Three phase, Two Phase, Single Phase we can choose accordingly in the analyser also.
  3. The following steps are configuring the available wiring setup of Krykard ALM-32/33/35 for the electrical system which we want to analyse.

  • Press Configuration Button
  • Select Electrical Connection
  • Select the appropriate Configuration from the list of connections.
  • Available connections are- 3 Phase 3 Wire, 3 Phase 4 Wire, Single Phase 2 Wire, Split Phase 3 Wire.

ALM-33 CONNECTION CONFIGURATION

  • Connection example shown in the above picture.
  • Analyser we could use to connect in HT side (like 11kV, 33kV), LT side (like 415V, 690V) by taking CT and PT reference from the Breaker panel (ex. VCB).
  • We can analyse the load in feeder wise as well as connecting the particular load also (like VFD, DC Drive, etc.)

PT & CT PROBE SELECTION AND CONFIGURATIONS

  • This probe for connecting the PT reference side or PRIMARY side or Direct BUS BAR SIDE.

  • Press Configuration Button
  • Select Sensors and ratios and press Enter
  • Select the corresponding Function key for voltage (U)
    • 110V is common PT secondary voltage.
    • Select Ratio set-up and press Enter for Change PT ratio as per the Primary Voltage by using navigation keys.
    • Connecting in Live BUS BAR side PT ratio should be 3U 1/1
    • Example: Connecting in 33kV side VCB/Breaker side means PT ratio will be 0033.0k/0110.0
  • Press Enter after  the changes are made.
  • Press Return button after the changes.

  • This probe is for connecting in Measuring or Protection CT

  • The pictures show how to connect the probe in to the CT reference side.

  • Press Configuration Button
  • Select Sensors and ratios and press Enter
  • Select the corresponding Function key for current (A)
  • Select Ratio set-up 3A.
  • Press Enter after the changes are made (CT Ratio).
  • If we select Ratio set-up A1+A2+A3, for changing the CT ratio for individual phase.
  • For Neutral sensor, it is not available in ALM 33; By selecting 3 Phase 4 Wire configuration there will record Neutral Voltage & Current readings in virtual which we can by the display also.
  • Press Return button (Back to the previous screen)

 

  • This probe for connecting to the PRIMARY side or direct BUS BAR side.

  • Press Configuration Button
  • Select Sensors and ratios and press Enter
  • Select the corresponding Function key for current (A)
  • Select Ratio set-up 3A 1/1.
  • Set the ratio for 65A to 6500A. It can measure up to 1000A.
  • Press Return button (Back to the previous screen)

*After this above setup, the Analyser is ready for measurement.

MEASURING PROCEDURE

  1. After doing the initial setup now the Krykard ALM-32/33/35 is ready for taking the measurements.
  2. The following steps are for checking the connection and then proceed to start the measurement.

PHASE SEQUENCE

* The figures below explained for the correct connection setup.

This is the first thing should check for the connection verification.

  • After the connection is made, Press Waveform display Mode key the above screen will appear.
  • Use Navigation keys to see Voltage (3U) or Current (3A) waveform.
  • Select corresponding Function keys to see THD, CF (Crest Factor) and all.
  • Select this function key for Vector view of Current & Voltage (Explained detailed in below)
    • The below two screens are vector view of Voltage and Current.
    • In 3 Phase 3 Wire configuration, the directions should be clockwise and order should be Red-Yellow-Blue (RYB).

  • In 3 Phase 4 Wire configuration, the directions should be clockwise & order should be Red-Yellow-Blue (RYB)

  • Compare the Amperes and with Analyser and the connected Breaker panel side or Load side.
    • Check the amperes in the Multifunctional meter or Ammeter of the Breaker panel.
    • If the Ampere is not matching with the load side check the CT ratio fixed. If it is wrong change it accordingly.
  • if amperes match check the Directions of vector as per the above diagrams.
    • If the directions are not proper check the CT Probe direction in the breaker panel.
  • Both Amperes should match.

POWER & ENERGY

  • Press  Power parameter mode key, the above screen will appear.
    • Check the Actual Power (W), Apparent Power (VA),
    • Both values should be in Positive (+ve).
    • If the values are Negative (-ve) invert the CT probe direction fixed in the breaker panel.
    • Check for the Phase Sequence/CT probe direction in Breaker panel.

HARMONICS

  • Press Harmonics mode key, the above screen will appear.
  • We can see the harmonics in % and in terms of Amperes for voltage as well as current by using navigation keys in the screen.
  • Use corresponding Function key for seeing Voltage Harmonics (U) / Current Harmonics (A).
  • Till 50th order voltage and current harmonics recording available.

TREND MODE

  • Press button and select Trend mode the above screen will appear.
  • This is for selection of parameters we wanted to record.
  • Use corresponding Function keys to Select/Unselect the parameter.
  • After selecting all the parameters, Press Return button for the previous screen.
  • Then select Trend mode key for Start the recording.

TREND MODE is the function used to Start Measurements & Monitor the readings.

  • After selecting Trend mode key recording list screen will appear.
  • Select the Function key for Recording schedule, the above screen will appear.
  • Enter the Record Name, Star & Stop time by using Navigation Keys.
  • Period is the sampling time for data recording.
    • 20s (seconds) means the analyser will record every 20 seconds per data.
    • The data will be the Minimum, Maximum & Average of 20 seconds data.
    • In Krykard ALM-32/33/35 the Interval limit from 1s (Seconds) to 15 mins (Minutes).
  • After entering all the details Press this button to start.
  • After starting the recording the below screen will appear.

  • During recording time, we will be able to see THD, RMS, Current & Voltage Phase sequence, Crest Factor, Power Parameters by selecting Function keys & Mode keys.

  • After reaching STOP TIME / Finishing the measurement, it will SAVE automatically.
  • If we want to STOP in between the measurement Press in Trend mode screen, it will stop immediately and save the records. We can stop the measurement in between the record time.
  • In that Trend mode select the recording list will appear. In this we can see the recorded measurements and the waveform of the record by Enter the selected record.

Check out:  Fluke-435 Tutorial

Thanks for reading this article. Will see you again with a new article. Until then bye from Dr. InPhase!!! For any feedback contact us to info@inphase.in or call +919632421402.

 

Dr InPhase Edu Series – An Exercise in Reactive Power Calculation

Doctor_Character-04-1Good day every body, Today on our Edu Series we will focus on some practical knowledge related to Reactive Power calculation.  Calculating your reactive power is critical as it can help make sure that your design is reliable and you get a reliable power factor output.

Consider an electrical network with the details below,

Demand = 2500kVA; Initial PF1 = 0.76; Desired PF2=0.97.

The reactive power required to achieve the desired PF (0.97), is calculated as below:

We know that

Where φ is the angle between voltage and current vectors.

From the above,

Now here arises the doubt. We say, the above method of calculation is flawed. There is a fundamental electrical engineering mistake. Before you go on any further, we would like you to think and comment in the comments section below if you find the flaw. Because once you scroll down, you are likely to lose your unique perspective on the above. Therefore, please comment and proceed for the answer below. This can help knowledge sharing with numerous angles / perceptions. Thanks in advance for that.

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The mistake is in Point ②. We have considered the same kVA for ① where the pf is 0.76, and② where the pf is 0.97. When actually, it is Real Power or kW which remains constant. Load remains unchanged, which in other words translates into constant kW and NOT constant kVA.  The same is shown in the diagram below:

From the above diagram, we know now the ‘kvar’ required to improve the system from PF1 to PF2 (i.e, 0.76 to 0.97) is,

Applying Pythagoras theorem for the above diagram,

And,

Which implies, [kvar1 = kW × tan φ1] and [kvar2 = kW × tan φ2]. Substituting these in equation ④,

In terms of power factors,

This is a generic formula to calculate the reactive power demand when the present power factor and the desired power factor are known. The same formula reduces to the following for desired power factor being Unity.

Where φ is the power factor angle.

We sincerely hope that this exercise helps you in calculating reactive power demand with more clarity.

Do you have a Challenging Power Factor Correction or Compensation issue, no matter how dynamic your load or reactive power is we can find the right solution for you. Get in touch with us today.

This article was originally published in www.pqindia.in.

The author Mr. Hasan Mydin is part of the “Advanced Power Quality Solutions” department at InPhase. He is a self-confessed Power Quality enthusiast with more than a decade’s experience solving power quality problems across India and even abroad. To know more about him, check out  his LinkedIn Profile.

Meet you again with a interesting article, until then  bye from Dr.InPhase

Thank you!

Doctor_Character-71

Thanks for reading…if you have questions don’t forget to ask me. You could write to me to info@inphase.in or call +919632421402