OPERATING MANUAL POWER QUALITY ANALYZERS PQM-702 PQM-703 SONEL SA ul. Wokulskiego 11 58-100 Świdnica, Poland Version 1.1, 20.03.
CONTENTS 1 General Information ............................................................................... 6 1.1 1.2 1.3 1.4 1.5 1.6 1.7 2 Safety .............................................................................................................6 General characteristics ................................................................................... 7 Power supply of the analyzer..........................................................................9 Tightness and outdoor operation ..
3.9 3.10 3.10.1 3.10.2 3.11 3.12 3.13 4 Threshold method ............................................................................................... 48 Slew rate (dV/dt) method .................................................................................... 49 Current limiting function ................................................................................ 49 Event detection .............................................................................................
6.4.3 6.4.4 6.4.5 6.4.6 6.4.7 6.4.8 6.4.9 6.4.10 6.4.11 6.4.12 Voltage ............................................................................................................... 93 Current ............................................................................................................... 93 Frequency........................................................................................................... 94 Harmonics ........................................................................
PQM-702, PQM-703 Operating Manual 1 General Information 1.1 Safety PQM-702 and PQM-703 are designed to measure, record and analyze power quality parameters. In order to provide safe operation and correct measurement results, the following recommendations must be observed: Before you proceed to operate the analyzer, acquaint yourself thoroughly with the present manual and observe the safety regulations and specifications provided by the producer.
1 General Information 1.2 General characteristics Power Quality Analyzers PQM-702 and PQM-703 (Fig. 1) are high-tech devices providing their users with a comprehensive features for measuring, analyzing and recording parameters of 50/60 Hz power networks and power quality in accordance with the European Standard EN 50160. Analyzers are fully compliant with the requirements of IEC 61000-4-30:2011, Class A.
PQM-702, PQM-703 Operating Manual read-out may be also be carried out by one of the three available communication links: USB, OR-1 radio receiver, and GSM modem. The device is provided with a built-in GSM modem (UMTS standard) and an antenna. This solution provides it with almost unrestricted access to the analyzer from any chosen global location with available GSM network. On the left side of its housing the analyzer has a SIM card, which is required for data transmission via GSM networks.
1 General Information Fig. 2. The rear wall of the analyzer. 1.3 Compared to PQM-702 model, PQM-703 analyzer additionally enables the user to: measure the transient voltages in the range of ±6 kV with sampling rate from 100 kHz to 10 MHz. Measuring circuits for transients are independent from the rest of voltage circuits and connected to voltage inputs L1, L2, L3, N, PE. The analyzer has four measurement channels: L1-PE, PEL2, L3-PE and N-PE.
PQM-702, PQM-703 Operating Manual Note The battery may be replaced only by the manufacturer's service department. 1.4 Tightness and outdoor operation The analyzer is designed to work in difficult weather conditions - it can be installed directly on electric poles. Two bands with buckles and two plastic fasteners are used for mounting the analyzer. The fasteners are screwed to the back wall of the housing, and bands should be passed through the resulting gaps. Fig. 3.
1 General Information The heater is powered from the AC/DC power adapter, and its power is limited to approx. 10 W. Due to the characteristics of the built-in lithium-ion rechargeable battery, the process of charging is blocked when the battery temperature is outside the range of 0C…60C (in such case, "Sonel Analysis 2" software indicates charging status as "charging suspended"). 1.5 Mounting on DIN rail The device is supplied with a bracket for mounting the analyzer on a standard DIN rail.
PQM-702, PQM-703 Operating Manual 1.
1 General Information Tab. 1. Measured parameters for different network configurations.
PQM-702, PQM-703 Operating Manual 1.7 Compliance with standards The analyzer is designed to meet the requirements of the following standards.
2 Operation of the analyzer 2 Operation of the analyzer 2.1 Buttons The keyboard of the analyzer consists of four buttons: ON/OFF , LEFT , RIGHT , START/STOP . To switch-on the analyzer, press ON/OFF button. Directional buttons LEFT and RIGHT are used primarily to change the information screens. The screens change circularly, i.e. after pressing RIGHT button, when 9/9 screen is displayed, the device goes to screen 1/9. After pressing LEFT button, screens are displayed in reverse order.
PQM-702, PQM-703 Operating Manual 2.4 Screens Fig. 5 presents the first screen displayed by the analyzer. The bar in the upper part is a permanent element, shown independent of the selected screen. Fig. 5. Screen 1 with a phasor diagram. The bar includes (from the left): o number of active measurement point: P1, P2, P3 or P4.
2 Operation of the analyzer Note To detect a phase error, the fundamental component of the measured sequence must be at least equal to 5% of the nominal voltage, or 1% of the nominal current. If this condition is not fulfilled, the correctness of angles is not verified. This feature allows user to perform quick visual assessment of mains parameters and their compliance with the analyzer settings. Screen 2 is shown in Fig. 6.
PQM-702, PQM-703 Operating Manual Fig. 8. Screen 4 with apparent and deformation power values. Screen 5 (Fig. 9) indicates THD factors in voltage and current. The factors shown on this screen are related to the fundamental component. Fig. 9. Screen 5 with THD factors. On screen 6 (Fig. 10) Power Factors (PF) are presented along with tan (i.e. the ratio of reactive power to active power). Fig. 10. Screen 6 with power factors and tan.
2 Operation of the analyzer Fig. 11. Screen 7 with flicker. Screen 8 presents the following information: Fig. 12. Screen 8.
PQM-702, PQM-703 Operating Manual Screen 9 (Fig. 13) allows user to quickly view the main configuration parameters of the measurement point: mains system, clamps type, nominal values of: voltage, current and frequency. Fig. 13. Screen 9 with information on the measurement point settings. 2.5 "Sonel Analysis 2" software "Sonel Analysis 2" is an application required to work power analyzers of PQM series.
2 Operation of the analyzer o phasor diagrams for voltages, o current and voltage waveforms drawn in real-time, o all other measured parameters not listed here. Analyzer configuration, remote triggering and stopping of the recording process. When connected to a PC, the display shows message "PC Connection" and the type of connection. When connected to a PC, all analyzer buttons are locked except button, but when the analyzer operates with key lock mode (e.g.
PQM-702, PQM-703 Operating Manual 2.6.2 Radio communication via OR-1 After connecting OR-1 radio module to a PC, the user may communicate with the analyzer using 433 MHz band. The range in this mode is limited to about 5 m, and the maximum rate data of data transmission is 57.6 kbit/s Note Before connecting to the analyzer through a wireless connection (OR-1 or GSM), the user must add the analyzer to the database of analyzers (Options Analyzer database in "Sonel Analysis 2").
2 Operation of the analyzer 2.7 Taking measurements 2.7.1 Measurement Points The analyzer allows the user to store four completely independent measurement configuration, which are called "measurement points." Number of active measurement point is shown in the upper left corner of the screen. Press buttons and at the same time and hold them pressed for 1 second to display the screen for selecting the measurement point Fig. 14. Fig. 14. Selection of the measurement point.
PQM-702, PQM-703 Operating Manual Starting the recording mode depends on how its configuration during the configuration of the measurement point. There are three modes available: Immediate start - when recording begins immediately after pressing the button. start after detecting the first event - in such case the analyzer waits for the record-triggering event. i.e. when the first of the parameters configured for the measurement point exceeds the threshold triggering the event.
2 Operation of the analyzer according to the "Power and harmonics" profile all possible parameters all possible parameters all possible parameters all possible parameters 2.8 1s 10 min 10 s 10 s 10 s 3-phase wye (1000 events) (1000 events) 22.5 day 3-phase wye 3-phase wye 4 years 25 days 1-phase 1-phase 64 days (1000 events / day) (1000 events / day) 14.
PQM-702, PQM-703 Operating Manual Note In order to correctly calculate total apparent power Se and total Power Factor (PF) in a 4-wire 3-phase system, it is necessary to measure the current in the neutral conductor. Then it is necessary to activate option Nconductor current and connect 4 clamps, as shown in Fig. 17. Another option is to turn on analytical calculation of current IN. More information on total apparent power Se - see sec. 5.3.5.
2 Operation of the analyzer Fig. 15. Wiring diagram - single phase. Fig. 16. Wiring diagram - split-phase.
PQM-702, PQM-703 Operating Manual Fig. 17. Wiring diagram - 3-phase wye with a neutral conductor. Fig. 18. Wiring diagram - 3-phase wye without neutral conductor.
2 Operation of the analyzer Fig. 19. Wiring diagram - 3-phase delta. Fig. 20. Wiring diagram - 3-phase delta (current measurement using Aron method).
PQM-702, PQM-703 Operating Manual Fig. 21. Wiring diagram - 3-phase wye without neutral conductor (current measurement using Aron method). Fig. 22. Wiring diagram - a system with transducers.
2 Operation of the analyzer Note Frequency response of transformers is usually very narrow, so the network disturbances at high frequencies (e.g. lightning surges) are largely suppressed and distorted on the secondary side of the transformer. This should be taken into account when making transient measurements in configuration with transformers. 2.
PQM-702, PQM-703 Operating Manual found analyzer by double-clicking it. If the analyzer has not been added yet to the database of the analyzers in the program, a window will be displayed prompting user to enter PIN code of the analyzer. Default factory code is "000" (three zeroes). Proper connection is confirmed by displaying window "Connection established" (the analyzer screen will display "Connected to PC (USB)". Step 6: Then a message will be displayed asking user to confirm the read-out of settings.
2 Operation of the analyzer To change the main settings of the measurement point, single-click Measurement point 1 at 'Local' panel. The screen should look as sown in Fig. 23. Set the following items: mains system (element as in Fig. 23) as a single-phase, nominal voltage at 230/400 V, nominal frequency at 50 Hz, averaging period at 1 s, triggering at Immediate, event detection hysteresis at 1.
PQM-702, PQM-703 Operating Manual At Harmonics card and Voltage tab select fields for THD average values and for voltage harmonic amplitudes - uncheck other boxes. List "THD calculated from" may be set according to own requirements. At Interharmonics card and in Voltage and Mains signalling uncheck all the boxes. Step 9: Settings of the measurement point has been properly prepared. The next step is to send the settings to the analyzer. The memory card will be formatted. To do this press Send button.
2 Operation of the analyzer Step 14: Displaying graphs with harmonics. Two types of graphs may be displayed for harmonics. The first one is a graph of recorded harmonics during the recording period. To display the graph, first select the time column and then the columns of selected harmonics (e.g. third and fifth order) and click Plots Time plot. The second type of the graph is a bar graph of harmonics. It shows all the harmonics in selected 1second interval (one row).
PQM-702, PQM-703 Operating Manual 2.10.3 Data flagging concept The analyzer saves measurement records along with the flag indicating the lack of time synchronization. If for the whole averaging period the analyzer was synchronized to UTC, then the flag is not turned on and during data analysis the icon indicating the lack of synchronization is not displayed. The absence of this icon indicates full compliance of gathered data with Class A in terms of time marking.
2 Operation of the analyzer If possible, before starting the process of recording, receive the GPS signal to synchronize the analyzer time to UTC. This will ensure the least possible timing errors during the recording and a fast tuning time in case of a temporary loss of GPS signal.
PQM-702, PQM-703 Operating Manual IP number assigned to SIM card (it must be a static number), APN (Access Point Name), user name and password (optional, usually not required). Configure the analyzer for GSM connectivity in the following manner: connect to the analyzer via a USB cable. If the analyzer is not present in the database it should added to it. it is necessary to check whether the modem is turned on.
2 Operation of the analyzer Fig. 25. Entering GSM settings in the analyzer database If you remove the SIM card from the slot, the analyzer will display error message "No SIM card". This message is repeated during next activations of the analyzer. Removing the SIM card while the analyzer is in operating mode, it is not recommended, as it prevents correct analyzer logging off from the GSM network. Note After any change in GSM settings, its automatic restart is initiated. 2.11.
PQM-702, PQM-703 Operating Manual 2.11.4 Possible problems with GSM settings and troubleshooting Problem: The search progress bar quickly reaches 100% and no analyzer is found. Possible cause: It may indicate that GSM search is disabled in program settings or in the analyzer database. Solution: from program menu select Options Program settings Media settings Active media. Check TCP/IP over GSM box. Problem: The search progress bar in a few sec. reaches 100% and no analyzer is found.
2 Operation of the analyzer the analyzer and on screen <8/9> check the status of GSM (whether the connection is made properly). The card may be also unlocked by inserting it into any mobile phone and entering PUK code and a new PIN code. Note: several attempts to enter incorrect PUK code will result in irreversible blocking of the SIM card! Problem: The analyzer reports GSM errors: "Network Error", "SMS Error", "No network" or other. Possible Cause: One of GSM network errors occurred.
PQM-702, PQM-703 Operating Manual using buttons on the keyboard, the user can enter the correct unlock code: button may be used to enter the correct unlock code: whereas button changes numbers in sequence 0, 1, 2…9, 0 at the first position, button on the second and button on the third.
3 Design and measurement methods 3 Design and measurement methods 3.1 Voltage inputs The voltage input block is shown in Fig. 26. Two measurement blocks are shown: on the right side of terminals main voltage circuits are presented - they are used for majority of voltage measurements. Sampling frequency of this circuit is 10.24 kHz. Three phase inputs L1, L2, L3 and protective conductor PE have common reference line, which is the N (neutral) conductor.
PQM-702, PQM-703 Operating Manual The ideal integrator has infinite gain for DC signals which descends at a rate of 20 dB/frequency decade. The phase shift is constant over the entire frequency range and is equal to 90°. Theoretically infinite gain for DC signal, when present at integrator input, causes the input saturation close to the supply voltage and prevents its further work. In practical systems, a solution is introduced to limit the gain for DC signals to some fixed value.
3 Design and measurement methods Locked Loop circuit as a reference signal. PLL circuit generates a frequency which is a multiple of the reference frequency required to clock the ADC. The need for the phase-locked loop results directly from the requirements of IEC 61000-4-7 standard, which describes the methodology and acceptable errors when measuring harmonics.
PQM-702, PQM-703 Operating Manual measurement window and is approximately 5 Hz. The analyzer collects 2048 samples per measurement window (for 50 Hz and 60 Hz), thus it fulfills the requirement for FFT stating that the number of samples subject to transformation equals a power of 2. It is essential to maintain a constant synchronization of the sampling frequency with the mains. FFT may be performed only on the data containing an integer multiple of the network period.
3 Design and measurement methods Fig. 28. Determining interharmonics subgroups (50 Hz system) Each interharmonic subgroup is the sum of RMS for seven (for 50 Hz mains) or nine (for 60 Hz mains) spectral lines obtained by Fourier transform. The exception is zero subgroup, i.e. sub-harmonic subgroup that contains one line more - 5Hz. It is presented in Fig. 28 with an example of 50 Hz network. Interharmonic subgroup of 0 order, i.e. subharmonic, consists of eight lines with frequencies from 5Hz to 40Hz.
PQM-702, PQM-703 Operating Manual Tab. 4. Summary of transient measurement modes in PQM-703. Sampling frequency Rise time with dV/dt method 10 MHz 5 MHz 1 MHz 500 kHz 100 kHz 100 V/5 µs 100 V/10 µs 100 V/50 µs 100 V/100 µs 100 V/500 µs Recording time range (2000...20000 samples) 0.2…2 ms 0.
3 Design and measurement methods does not exceed the set threshold will not be detected by the analyzer. In this mode, the waveform rise time is not taken into account. Both slow and fast transients will be detected, when the amplitude criterion is met. 3.10.2 Slew rate (dV/dt) method Slew rate method (dV/dt) is activated by selecting Slew rate and indicating an appropriate sampling rate, which indirectly selects the voltage slew rate from several available values (see Tab. 4).
PQM-702, PQM-703 Operating Manual Zeroing is highlighted in live mode and in analysis. In order to distinguish between the actual measured value from zeroed value of reset parameter, the following rules apply: in live mode, the zeroed values are marked with * symbol (asterisk) next to a value (e.g. 0.000 *). in the data analysis, the heading of a parameter that can be zeroed is marked by adding * symbol, e.g.
3 Design and measurement methods K-Factor Voltage transients Mains signalling K Ut UR1, UR2 (1) applies to UN-PE voltage (2) with C-5 clamps only Detected events are recorded on a memory card as an entry containing: parameter type, channel, in which the event occurred, start and end time of the event, the threshold value set by the user, parameter extreme value measured during the event, parameter average value measured during the event.
PQM-702, PQM-703 Operating Manual for events related to DC voltage and UN-PE voltage, the hysteresis is calculated as a percentage of the threshold value, but not less than 50 mV (referred to input). for remaining parameters, the hysteresis is specified as a percent of maximum threshold (e.g. when maximum threshold for current crest factor has been set to 4.0 the hysteresis is 0.02×4.0 = 0.08.) 3.
4 Calculation formulas 4 Calculation formulas 4.
PQM-702, PQM-703 Operating Manual Displacement power factor cos DPF - Tangent tan - Harmonic components of voltage and current Uhx Ihx V A Total Harmonic Distortion for voltage, referred to the fundamental component THDUF - Total Harmonic Distortion for voltage, referred to RMS THDUR - Total Harmonic Distortion for current, referred to the fundamental component THDIF - Total Harmonic Distortion for current, referred to RMS THDIR - Interharmonic components of voltage and current Ui
4 Calculation formulas 𝑚𝑎𝑥|𝐼𝑖 | 𝐼𝐴𝑅𝑀𝑆 where the operator 𝑚𝑎𝑥|𝐼𝑖 | expresses the highest absolute value of current IA samples i = 2048 for 50 Hz and 60 Hz 2 2 ∑50 ℎ=1 𝐼ℎ ℎ 𝐾𝐹𝑎𝑐𝑡𝑜𝑟 = 2 𝐼1 where Ih is the h-th harmonic of current IA I1 is fundamental component of current IA 𝑃ℎ = 𝑈ℎ 𝐼ℎ cos 𝜑ℎ where Uh is the h-th harmonic of voltage UA-N Ih is the h-th harmonic of current IA h is the angle between harmonics Uh and Ih 𝑄ℎ = 𝑈ℎ 𝐼ℎ sin 𝜑ℎ where Uh is the h-th harmonic of voltage UA-N Ih is the h-th harmonic of cur
PQM-702, PQM-703 Operating Manual 𝑚 𝐸𝑄1+ = ∑ 𝑄1+ (𝑖)𝑇(𝑖) 𝑖=1 𝑄 (𝑖) 𝑓𝑜𝑟 𝑄1(𝑖) > 0 𝑄1+ (𝑖) = { 1 0 𝑓𝑜𝑟 𝑄1(𝑖) ≤ 0 𝑚 𝐸𝑄1− = ∑ 𝑄1− (𝑖)𝑇(𝑖) Reactive energy of fundamental component (consumed and supplied) EQ1+ EQ1- 𝑖=1 varh 𝑄1− (𝑖) = { |𝑄1 (𝑖) | 𝑓𝑜𝑟 𝑄1 (𝑖) < 0 0 𝑓𝑜𝑟 𝑄1(𝑖) ≥ 0 where: i is subsequent number of the 10/12-period measurement window, Q1(i) represents reactive power of fundamental component Q1 calculated in i-th measuring window, T(i) represents duration of i-th measuring window (in hours) 𝑚 𝐸
4 Calculation formulas 𝑚 𝐸𝑃+𝑡𝑜𝑡 = ∑ 𝑃𝑡𝑜𝑡+ (𝑖)𝑇(𝑖) 𝑖=1 𝑃 (𝑖) 𝑓𝑜𝑟 𝑃𝑡𝑜𝑡 (𝑖) > 0 𝑃𝑡𝑜𝑡+ (𝑖) = { 𝑡𝑜𝑡 0 𝑓𝑜𝑟 𝑃𝑡𝑜𝑡 (𝑖) ≤ 0 𝑚 𝐸𝑃−𝑡𝑜𝑡 = ∑ 𝑃𝑡𝑜𝑡− (𝑖)𝑇(𝑖) Total active energy (consumed and supplied) EP+tot EP-tot 𝑖=1 Wh 𝑃𝑡𝑜𝑡− (𝑖) = { |𝑃𝑡𝑜𝑡 (𝑖)| 𝑓𝑜𝑟 𝑃𝑡𝑜𝑡 (𝑖) < 0 0 𝑓𝑜𝑟 𝑃𝑡𝑜𝑡 (𝑖) ≥ 0 where: i is subsequent number of the 10/12-period measurement window, Ptot(i) represents total active power Ptot calculated in i-th measuring window T(i) represents duration of i-th measuring window (in hours) 𝑚 𝐸𝑄𝐵+𝑡𝑜𝑡 = ∑ 𝑄𝐵𝑡𝑜𝑡+ (𝑖)𝑇
PQM-702, PQM-703 Operating Manual 4.3 3-phase wye network with N conductor 3-phase wye network with N conductor (parameters not mentioned are calculated as for single-phase) Name Parameter Designation Method of calculation Unit Total active power Ptot W 𝑃𝑡𝑜𝑡 = 𝑃𝐴 + 𝑃𝐵 + 𝑃𝐶 Total Budeanu reactive power QBtot var 𝑄𝐵𝑡𝑜𝑡 = 𝑄𝐵𝐴 + 𝑄𝐵𝐵 + 𝑄𝐵𝐶 Total reactive power acc.
4 Calculation formulas Total reactive energy of fundamental component (consumed and supplied) EQ1+tot EQ1-tot varh calculated as for the split-phase network 𝑚 𝐸𝑆𝑡𝑜𝑡 = ∑ 𝑆𝑒 (𝑖)𝑇(𝑖) 𝑖=1 Total apparent energy EStot VAh RMS value of zero voltage sequence U0 V where: i is subsequent number of the 10/12-period measurement window Se(i) represents the effective apparent power Se, calculated in i-th measuring window T(i) represents duration of i-th measuring window (in hours) 1 𝑈0 = (𝑈𝐴1 + 𝑈𝐵1 + 𝑈𝐶1 ) 3 𝑈
PQM-702, PQM-703 Operating Manual A 1 (𝐼 + 𝑎𝐼𝐵1 + 𝑎2 𝐼𝐶1) 3 𝐴1 𝐼1 = 𝑚𝑎𝑔(𝐼1) where IA1, IB1, IC1 are vectors of fundamental current components IA, IB, IC Operator mag() indicates vector module I2 A 1 𝐼2 = (𝐼𝐴1 + 𝑎2 𝐼𝐵1 + 𝑎𝐼𝐶1 ) 3 𝐼2 = 𝑚𝑎𝑔(𝐼2) where IA1, IB1, IC1 are vectors of fundamental components for phase voltages IA, IB, IC Operator mag() indicates vector module i0 % i2 % 𝐼1 = Current positive sequence component Current negative sequence component Current zero sequence unbalance ratio Curre
4 Calculation formulas 𝑆𝑒𝑁 = √𝑆𝑒 2 + 𝑆𝑒1 2 where: 𝑆𝑒1 = 3𝑈𝑒1 𝐼𝑒1 Effective apparent distortion power SeN VA 𝑈𝑒1 = √ 𝑈𝐴𝐵1 2 + 𝑈𝐵𝐶1 2 + 𝑈𝐶𝐴1 2 9 𝐼𝑒1 = √ Total Power Factor PFtot - Active energy (consumed and supplied) EP+tot EP-tot Wh 𝐼𝐴12 + 𝐼𝐵1 2 + 𝐼𝐶12 3 𝑃𝐹𝑡𝑜𝑡 = 𝑃𝑡𝑜𝑡 𝑆𝑒 calculated as for the split-phase network 𝑚 𝐸𝑆𝑡𝑜𝑡 = ∑ 𝑆𝑒 (𝑖)𝑇(𝑖) 𝑖=1 Total apparent energy EStot VAh where: i is subsequent number of the 10/12-period measurement window Se(i) represents the total apparent power Se calcul
PQM-702, PQM-703 Operating Manual 5 Power quality - a guide 5.1 Basic information The measurement methodology is mostly imposed by the power quality standards, mainly IEC 61000-4-30:2009. This standard, introducing precise measurement algorithms, ordered analyzers market, allowing customers to easily compare the devices and their results between the analyzers from different manufacturers.
5 Power quality - a guide This type of current transformer has several distinguishing features. It may be used to measure very high currents and its power consumption is low. Magnetizing current causes a phase shift (tenth of a degree), which may introduce an error in power measurement (especially at low power factor). The disadvantage of this type of clamps is the core saturation when very high currents are measured (above the nominal range).
PQM-702, PQM-703 Operating Manual Rogowski coil has some undeniable advantages compared with current transformers. As it does not have a core, the core saturation effect is eliminated; thus being a perfect instrument to measure high currents. Such coil has also an excellent linearity and a wide pass band, much wider than a current transformer, and its weight is much smaller. However, until recently the wider expansion of flexible clamps in the current measurement area was difficult.
5 Power quality - a guide which is determined once every 10 minutes and long-term Plt, which is calculated on the basis of 12 consecutive Pst values, i.e. every 2 hours. Long time of measurement results directly from the slow-changing nature of this phenomenon - to collect sample data the measurement must be long.
PQM-702, PQM-703 Operating Manual 𝑃 = 𝑈𝐼𝑐𝑜𝑠𝜑 where: U is RMS voltage, I is RMS current and is the phase shift angle between voltage and current. The active power is calculated by the analyzer directly from the integral formula, using sampled voltage and current waveforms: 𝑀 𝑃= 1 ∑ 𝑈𝑖 𝐼𝑖 𝑀 𝑖=1 where M is a number of samples in 10/12-period measuring window (2048) and Ui and Ii are successive voltage and current samples. 5.3.
5 Power quality - a guide ∞ 𝑄𝐵 = ∑ 𝑈𝑛 𝐼𝑛 sin 𝜑𝑛 𝑛=0 where Un and In are voltage and current harmonics of order n, and n are angles between these components.
PQM-702, PQM-703 Operating Manual schools have not been changed for years. This factor is often underestimated, though as a form of justification it can be said that this theory had not been refuted for 60 years. Secondly, in the 1920s there were no measuring instruments which could give insight in individual voltage and current harmonic components and it was difficult to verify new theories. Thirdly, distorted voltage and current waveforms (i.e.
5 Power quality - a guide 𝑃𝐹 = 𝑃 𝑃 = 𝑆𝑒 √𝑃2 + 𝐷 2 + 𝑄2 + 𝐷 2 𝑠 𝑢 In IEEE 1459-2000 standard, reactive power known as Q has been limited to the fundamental component and it applies both to single-phase and three-phase systems. In single-phase systems: 𝑄1 = 𝑈1 𝐼1 sin 𝜑1 In three-phase systems, only the positive sequence component is taken into account: 𝑄1+ = 3𝑈1+ 𝐼1+ sin 𝜑1+ Correct measurement of this power requires the same phase rotation sequence (i.e.
PQM-702, PQM-703 Operating Manual 5.3.4 Reactive power and reactive energy meters Reactive energy meters are devices unknown to the household users who for settlements with energy suppliers use the meters of active energy expressed in Wh or kWh. Household users are in a comfortable situation – they pay only for usable energy and do not have to think what the power factor is in their installations.
5 Power quality - a guide systems with traditional meters is subject to an additional error caused by creation of a virtual zero inside the meter which has little to do with actual zero of the receiver. On top of that, the manufacturers usually do not give any information about the applied measuring method. We may only wait for the next version of the standard, which will define (hopefully) the measuring and testing methods much more precisely, also for non-sinusoidal conditions. 5.3.
PQM-702, PQM-703 Operating Manual 𝐼𝑎 2 + 𝐼𝑏 2 + 𝐼𝑐 2 𝐼𝑒 = √ 3 𝑈𝑎𝑏 2 + 𝑈𝑏𝑐 2 + 𝑈𝑐𝑎 2 𝑈𝑒 = √ 9 In four-wire systems: 𝐼𝑎 2 + 𝐼𝑏 2 + 𝐼𝑐 2 + 𝐼𝑛 2 𝐼𝑒 = √ 3 2 3(𝑈𝑎 2 + 𝑈𝑏 2 + 𝑈𝑐 2 ) + 𝑈𝑎𝑏 + 𝑈𝑏𝑐 2 + 𝑈𝑐𝑎 2 𝑈𝑒 = √ 18 where Ia, Ib, Ic are RMS currents for individual phases (line or phase), I n is the RMS current in neutral conductor, Ua, Ub, Uc are RMS phase-to-neutral voltages, and Uab, Ubc, Uca are RMS phaseto-phase voltages.
5 Power quality - a guide 5.3.7 Power Factor True Power Factor or Power Factor (TPF or PF) is the value which takes into account also the presence of higher harmonics. For sinusoidal circuits, it is equal to Displacement Power Factor (DPF) i.e. popular cos. DPF is therefore a measure of the phase shift between the fundamental voltage and current components.
PQM-702, PQM-703 Operating Manual Let's try to answer two basic questions: What is the cause of harmonic components in voltage? What is the cause of harmonic components in current? Seemingly, these two questions are almost identical, but separation of current and voltage is extremely important to understand the essence of this issue.
5 Power quality - a guide where: Ph – active power of the h-th order harmonic, Uh – RMS voltage of the h-th order harmonic, Ih – RMS current of the h-th order harmonic, h – phase shift angle between the voltage and current harmonics of the h-th order. When Ph power has positive sign (+), then the dominating source of energy of this harmonics is on the energy supplier’s side. When it is negative, the receiver is the dominating source.
PQM-702, PQM-703 Operating Manual When the sign is positive (+), then the character is inductive, and when it is negative (-), it is capacitive. Passive source current may be reduced to zero when the following condition is met for each harmonic2: 𝐵ℎ + 𝐵𝑘ℎ = 0 where: Bh – receiver susceptance for the h-th harmonic, Bkh – parallel compensator susceptance for the h-th harmonic.
5 Power quality - a guide measured even order harmonics are of minimal value. If we consider this property, it turns out that the group of harmonics with the most undesirable properties is the 3rd, 9th, 15th (zero sequence), and the 5th, 11th, and 17th (negative sequence). The current harmonics which are multiples of 3 cause additional problems in some systems. In 4-wire systems, they have a very undesirable property of summing up in the neutral conductor.
PQM-702, PQM-703 Operating Manual 5.4.5 K-Factor K-Factor, also called the transformer loss factor is a measure used in determining the requirements for power transformers. Higher harmonics in current cause increased heat losses in windings and metal parts of the transformer. The main reasons is the presence of eddy currents generated by current components of higher frequencies and by the skin effect.
5 Power quality - a guide 400 300 200 100 0 -100 -200 -300 -400 Fig. 31. The effect of 9th harmonic interaction (450 Hz, 10% Unom) and interharmonic 460 Hz (10% Unom). The apparent change in the voltage envelope with frequency of 10Hz that may cause flicker (Unom = 230 V RMS, 50 Hz). 5.5.
PQM-702, PQM-703 Operating Manual Since the introduction of such signals to the power supply may have negative consequences for some devices, similarly to the effect of harmonics or interharmonics, EN 50160 standard defined limits for the 3-second mean values of such signals, as shown in Fig. 33. During the measurement, 99% of average 3-second control signals values must be below the specified limit. Low frequency signals (up to 3 kHz) are used for switching on/off the loads, filters and protection devices.
5 Power quality - a guide Fig. 33. Allowable levels of mains signalling according to EN 50160 standard. In networks with substantial contents of harmonics, where additional filters are used for reducing interferences, the consequences of their use may also include additional attenuation of the frequency range used for the signalling.
PQM-702, PQM-703 Operating Manual The analyzer is capable of measuring the voltage and current unbalance with a symmetrical components method. This method is based on the assumption that each set of three unbalanced vectors can be resolved to three groups of vectors: positive sequence, negative sequence and zero sequence. Fig. 34. Example of determining positive sequence component. Presented example shows the method for calculating voltage positive sequence component.
5 Power quality - a guide 𝑈2 ∙ 100% 𝑈1 where: u0 – unbalance factor for zero sequence, u2 – negative sequence unbalance, U0 – zero symmetric component, U1 – positive sequence symmetrical component, U2 – negative sequence symmetrical component. 𝑢2 = The most convenient method to calculate the symmetrical components and unbalance is using the complex number calculus. The vectors parameters are amplitude of the voltage (current) fundamental component and its absolute phase shift angle.
PQM-702, PQM-703 Operating Manual Interruption is a state during which URMS(1/2) voltage is lower than the specified interruption threshold. The interruption threshold is usually set much below the voltage dip level, at approx. 1..10% Unom. The voltage interruption starts at the moment when URMS(1/2) voltage decreases below the interruption threshold value, and ends at the moment when URMS(1/2) voltage is equal to or greater than the interruption threshold value plus the voltage hysteresis.
5 Power quality - a guide Fig. 37. Example of lightning surge. Surges caused by atmospheric discharges may have destructive effects due to the very high energy triggered during the discharge. Most of surges of this type observed in networks, result from voltage induced by close but not direct lightning stroke. In the area of lightning stroke, a very strong electromagnetic field is generated and long overhead/underground lines induce high voltage that penetrate into the distribution network.
PQM-702, PQM-703 Operating Manual does not exceed the double value of peak voltage in standard conditions), and then the disturbance is suppressed in oscillatory way. The oscillating nature of the disturbance is caused by the interaction of the capacitor capacitance with network inductance and resulting resonance. The oscillation frequency is usually around a few hundred Hz. The resistance in the circuit results in gradual suppression of these oscillations.
5 Power quality - a guide Fig. 39. Voltage tolerance curves: ANSI (ITIC) and CBEMA. The vertical axis of the graph presents voltage in percent of the nominal value, whereas the horizontal axis presents time (in logarithmic scale). The middle part of the graph (between curves) represents the area of the correct operation of the device.
PQM-702, PQM-703 Operating Manual 5.11 Averaging the measurement results Mains monitoring over a longer period means that a significant amount of data needs to be collected. To ensure that such data analysis is possible at all, it is necessary to introduce the mechanisms for reducing data size to the values acceptable by both, people and machines. Let us take the example of EN 50160 compliant power quality measurements The basic mains test period is one week.
5 Power quality - a guide Averaging with times less than 10 seconds is somewhat different. Although, they are all expressed in time units (200 ms, 1 s, 3 s, 5 s), in reality they are measured in multiples of the mains period. For example, selecting 3-second averaging period means averaging in the time equal to 150/180 mains cycles (fifteen 10/12-cycle measurements). Fig. 41. Determining the averaging intervals shorter than 10 seconds (with the 3-second averaging).
PQM-702, PQM-703 Operating Manual Selecting the right averaging time is not easy. To a large extent it depends on the type of disturbance in the system and the user's expectations for the final data analysis. A frequent situation is that we know only that there is a problem in the mains, and the measurements with the analyzer will only help us identify the cause. In this situation it is better to use shorter averaging times (e.g.
6 Technical data 6 Technical data Specifications are subject to change without prior notice. Recent revisions of technical documentation are available at www.sonel.pl. Basic uncertainty is the uncertainty of a measurement instrument at reference conditions specified Tab. 6. Provided uncertainties apply to the analyzer without additional transformers and clamps. Abbreviations: m.v.
PQM-702, PQM-703 Operating Manual 6.3 Transient module Transient detection module Number of input channels Maximum input voltage Peak input voltage DC voltage range Analog pass band (-3dB) A/C converter Sampling frequency 4 (L1-PE, L2-PE, L3-PE, N-PE) not galvanically isolated 760 VRMS 8000 V ±6000 V 2.
6 Technical data Fig. 42. Basic uncertainty multiplier M as a function of ambient temperature. 6.4.3 Voltage Voltage URMS (AC+DC) Crest Factor Range and conditions 10% Unom ≤ URMS ≤ 150% Unom for Unom ≥ 64 V 1..10 (1..1.65 for 690 V voltage) for URMS ≥ 10% Unom Resolution 0.01% Unom Basic uncertainty 0.1% Unom 0.01 5% 6.4.4 Current Current Range and conditions IRMS (AC+DC) Resolution Basic uncertainty Input path without clamps 0..1 V (0..3.6 Vp-p) 0.01% Inom 0.
PQM-702, PQM-703 Operating Manual Hard clamps C-7 Crest Factor 0..100 A (±360 Ap-p) 0.01% Inom Additional uncertainty 0..100 A: (0.5% + 0.02 A) (45..65 Hz) 0..100 A: (1.0% + 0.04 A) (40..1000 Hz) 1..10 (1..3.6 for Inom) for IRMS ≥ 1% Inom 0.01 5% 6.4.5 Frequency Frequency F Range and conditions 40..70 Hz 10% Unom ≤ URMS ≤ 200% Unom Resolution 0.01 Hz Basic uncertainty 0.01 Hz 6.4.6 Harmonics Harmonics Harmonic (n) URMS amplitude IRMS amplitude Voltage THD-R (n = 2..
6 Technical data 6.4.8 Harmonic Powers Harmonic Powers Active and reactive power of harmonics Conditions 80% Unom ≤ URMS < 150% Unom 5% Inom ≤ IRMS ≤ Inom Resolution depending on Unom and Inom Basic uncertainty (1) 2 ±√𝛿𝑈ℎ 2 2 + 𝛿𝐼ℎ + 𝛿𝑝ℎ % where: Uh – basic measurement uncertainty for voltage harmonic amplitude, Ih – basic measurement uncertainty for current harmonic amplitude, ph – basic uncertainty of the measurement of the phase between voltage and current harmonics. (1) See chapter 6.4.10.
PQM-702, PQM-703 Operating Manual 6.4.
6 Technical data Example Calculation of measurement uncertainty of active power fundamental component. Conditions: = 60, URMS Unom , IRMS = 5% Inom. 2 Basic uncertainty is ±√1.02 + 𝛿𝑝ℎ %. For the frequency range of 40..70 Hz, phase error of the analyzer is less than 0.5. After substituting equation: 𝛿𝑝ℎ = 100 (1 − 𝑐𝑜𝑠(𝜑+𝛥𝜑) 𝑐𝑜𝑠(60.5°) 𝑐𝑜𝑠𝜑 𝑐𝑜𝑠(60°) ) = 100 (1 − ) = 1.52% therefore, the measurement uncertainty is: 𝛿 = ±√1.02 + 1.522 = ±1.
PQM-702, PQM-703 Operating Manual 6.4.11 Flicker Flicker Pst (10 min.) Plt (2 h) Range and conditions 0,2…10 for URMS ≥ 80% Unom Resolution 0.01 Basic uncertainty 5% within the values presented in tables of IEC 61000-4-15 standard 6.4.12 Unbalance Unbalance (voltage and current) Unbalance ratio for positive, negative and zero sequence Range and conditions 0.0%...20.0% for 80% Unom ≤ URMS < 150% Unom Resolution Basic uncertainty 0.15% (absolute uncertainty) 0.1% 6.4.
6 Technical data 6.6 Event detection - other parameters Parameter Range Detection method Frequency (min, max) Voltage crest factor (min, max) Current crest factor (min, max) Voltage unbalance factor for negative sequence (max) Current unbalance factor for negative sequence (max) Short-term flicker Pst (max) 40 ... 70Hz (percentage or absolute value) 1.0 ... 10.0 Detection based on 10-sec. measurement (acc. to IEC 61000-4-30) Basing on 10/12-cycle value 1.0 ... 10.0 Basing on 10/12-cycle value 0.
PQM-702, PQM-703 Operating Manual 6.6.1 Event detection hysteresis Event detection hysteresis Hysteresis 6.7 Range Calculation method For each of the parameters calculated as a percentage of maximum threshold value (for exceptions see 3.12) 0..10% Recording Recorder Averaging time (1) 200 ms, 1 s, 3 s, 5 s, 10 s, 15 s, 30 s, 1 min, 3 min, 5 min, 10 min, 15 min, 30 min, 60 min, 120 min.
6 Technical data Apparent energy ES Voltage total harmonic distortion (THD) THD-F Current total harmonic distortion (THD) THD-F Voltage harmonic amplitudes Uh1…Uh50 Current harmonic amplitudes Ih1…Ih50 Voltage total interharmonic distortion TID-R Current total interharmonic distortion TID-F Voltage interharmonics amplitudes Uih0…Uih50 Current interharmonics amplitudes Iih0…Iih50 K-Factor (max) Harmonics active power (1…50) Ph1…Ph50 Harmonics reactive power (1…50) Qh1…Qh50 Angles between voltage and current
PQM-702, PQM-703 Operating Manual 6.
7 Equipment Immunity to series of fast transients/bursts Immunity to surges Emission of radiated RF disturbances Emission of conducted disturbances IEC 61000-4-4 Amplitude 2 kV, 5 kHz IEC 61000-4-5 Amplitude 2 kV (L-L), 4 kV (L-PE) IEC 61000-6-3 30…230 MHz, 30 dB(V/m) at 10 m 230…1000 MHz, 37 dB(V/m) at 10 m IEC 61000-6-3 Levels for a quasi-peak detector: 0.15 kHz…0.5 MHz: 66 dBV…56 dBV 0.5 MHz…5 MHz: 56 dBV 5 MHz…30 MHz: 60 dBV EN 55022 Compliance statement: PQM-703 is a class A product.
PQM-702, PQM-703 Operating Manual operating manual, guarantee card, calibration certificate. 7.
7 Equipment Warning Do not use the device on non-insulated conductors with a potential of more than 600 V in relation to the earth and a measurement category greater than III.
PQM-702, PQM-703 Operating Manual 7.2.2 C-5 current clamp The C-5 clamp is used to measure the alternating and direct current without interrupting the circuit with the flowing current. The measuring range is 1400 A for DC and 1000 A AC. The output signal is voltage proportional to the measured current. The clamp has one 1000 A measuring range, with the 1 mV/A sensitivity, DC zero adjustment knob, and LED power supply indicator. The output signal is supplied by a 1.
7 Equipment Phase error (45...65 Hz): Current range Phase error ratio: frequency range: output impedance: DC zero adjustment range: noise: 10…200 A 200…1000 A 2.5 2 1 mV/1 A DC...5 kHz 100 Ω ±10 A DC up to 1 kHz: 1mVp-p (or 1 Ap-p) DC up to 5 kHz: 1.5mVp-p (or 1.5 Ap-p) 1 Hz up to 5 kHz: 0.5mVp-p (or 0.5 Ap-p) Additional errors: caused by current frequency: 65..440 Hz: -2% 440..1000 Hz: -5% 1..
PQM-702, PQM-703 Operating Manual 7.2.3 C-6 current clamp The C-6 is used to measure the alternating current with frequencies up to 10 kHz in the 10 mA…10 A range. The output signal is voltage proportional to the measured current with the 100 mV/A sensitivity. The output signal is supplied by a 1.5-meter lead with a pin adapted for the socket in the meter. The arrow located on one of the jaws indicates the current flow direction.
7 Equipment maximum measured conductor diameter: clamp lead length: operating temperature: humidity: height: electromagnetic compatibility: 20 mm 1.5 m –10C…+55C 85% RH 2000 m IEC 61000-6-3:2008 IEC 61000-6-2:2008 7.2.4 C-7 current clamp C-7 Clamps are used to measure alternating currents in networks of low and medium power within the range up to 100 A. The output signal is a voltage proportional to the measured current at the sensitivity of 5 mV/A.
PQM-702, PQM-703 Operating Manual length of clamp cables: operating temperature: relative humidity: electromagnetic compatibility: 1.5 m 0C…+50C 85% (non-condensing) IEC 61326 7.2.5 F-1, F-2, F-3 current clamps F-1, F-2 and F-3 flexible clamps (Rogowski coil) are used to measure the alternating current of frequencies up to 10 kHz in the 1 A…3000 A range. The only difference between the F-1, F-2 and F-3 flexible clamps is the coil size. The electrical parameters are identical.
7 Equipment Linearity: ±0.2% Additional error caused by conductor position: ±2% max. Additional error caused by external magnetic field: ±0.5% max. Additional error caused by temperature: ±0.07% Output impedance: 30 /400 mm Remaining data: insulation type: measuring category acc. to IEC 61010-1: protection rating acc.
PQM-702, PQM-703 Operating Manual 8 Other Information 8.1 Cleaning and maintenance Note Use only the maintenance methods specified by the manufacturer in this manual. The casing of the analyzer may be cleaned with a soft, damp cloth using all-purpose detergents. Do not use any solvents or cleaning agents which might scratch the casing (powders, pastes, etc.). Cables should be cleaned with water and detergents, and then dried. The analyzer electronic system does not require maintenance. 8.2 8.
