PQVO3Sd Short duration voltage variations

Transcription

1 1MRS Issued: 6/2005 Version: A/ PQVO3Sd Short duration voltage variations Data subject to change without notice Contents 1. Introduction Features Short duration voltage variations Application Input description Output description Description of operation Configuration Voltage measurement Current measurement Input/output configuration Rated frequency Measuring mode Operation criteria Outputs of the function block Swell Sag Interruption Counters Indications and events Resetting Recorded Data Measurement accuracy Parameters and Events General Setting values Control Settings Measurement values Input Data Output Data Recorded data... 21

2 PQVO3Sd Distribution Automation Events Technical Data

3 Distribution Automation PQVO3Sd 1. Introduction 1.1 Features Single-phase, two-phase and three-phase voltage variation measurement. Voltage sag, swell and interruption measurement. Measurement according to IEC Recording of the 3 latest events, providing time stamps of event start and min/max measurement, duration and min/max voltage of each phase. Also measured currents preceding the event are recorded for each measured phase current. Counters for sag, swell and interruption events. 1.2 Short duration voltage variations Voltage variations are the most typical power quality events that have the largest impact on sensitive customers. Short-duration voltage variations are almost always caused by a fault condition. Depending on where the fault is located, the fault can cause either a temporary voltage rise (swell) or voltage drop (sag). A special case of a voltage drop is complete loss of voltage (interruption). The impact on the voltage during the actual fault condition is a short duration variation. The typical duration of a short duration voltage variation, as defined in most of the publications, is from 10 ms to 60 seconds. Sag A voltage sag is a sudden reduction of the supply voltage. In most publications, a voltage sag is characterized as a voltage drop to a value between 90 % and 1 % of the nominal voltage. Voltage sags are usually caused by system faults but can also be caused by the switching of large loads or the starting of motors. A typical voltage sag can also be associated with a single line-to-ground fault. A fault on a parallel feeder will result in a voltage drop at the substation bus. This fault affects all of the other feeders until the fault is cleared. Swell A voltage swell is defined as an increase in supply voltage. Typical magnitudes are between 110 % and 180 % of the nominal voltage. Swells are also usually associated with system faults, but not as frequently as voltage sags. A single line-to-ground fault in the system can result in a voltage swell on the healthy phases. Switching off large loads or switching on large capacitor banks can also cause voltage swells. 3

4 PQVO3Sd Distribution Automation Interruption A voltage interruption is defined as a decrease of the supply voltage to a value less than 1 % of the nominal voltage. Interruptions can be the result of power system faults, equipment failures, and control function failures. Utility protective devices and the particular event causing the fault determine the duration of an interruption. 1.3 Application The PQVO3Sd function block is used for measuring short duration voltage variations in distribution networks. Power quality is being evaluated in the voltage waveform by measuring voltage swells, sags and interruptions. Power quality measurements carried out by the function block PQVO3Sd follow the European Standard EN The measuring principles are taken from the International standard IEC Table 1. Protection diagram symbols as seen in the relay terminal ABB IEC ANSI PQVO3Sd PQ 3U<> PQ 3U<> For IEC symbols used in single line diagrams, refer to the manual Technical Descriptions of Functions, Introduction, 1MRS MUM Figure 1. PQVO3Sd function block symbol 4

5 Distribution Automation PQVO3Sd 1.4 Input description Name Type Description UL1_U12 Analog channel Input for measuring voltage UL1 or signal (SINT) U12 UL2_U23 UL3_U31 IL1 IL2 IL3 RESET Analog channel signal (SINT) Analog channel signal (SINT) Analog channel signal (SINT) Analog channel signal (SINT) Analog channel signal (SINT) Digital signal (BOOL, pos. edge) Input for measuring voltage UL2 or U23 Input for measuring voltage UL3 or U31 Input for measuring phase current IL1 Input for measuring phase current IL2 Input for measuring phase current IL3 Input signal for resetting the counters and registers of the function 1.5 Output description Name Type Description SWELL Digital signal Output indicating the start of a voltage (BOOL, active high) swell SAG INTERRUPTION SWELL_COUNTER SAG_COUNTER INT_COUNTER Digital signal (BOOL, active high) Digital signal (BOOL, active high) Unsigned integer (UINT) Unsigned integer (UINT) Unsigned integer (UINT) Output indicating the start of a voltage sag Output indicating the start of a voltage interruption Output indicating the amount of swells counted Output indicating the amount of sags counted Output indicating the amount of interruptions counted 5

6 PQVO3Sd Distribution Automation 2. Description of operation 2.1 Configuration Voltage measurement Voltage variation measurement (voltage sag/swell/interruption) can be done for phase-to-ground or phase-to-phase voltages. Voltages can be measured with conventional voltage transformers or voltage dividers (does not apply for phase-to-phase voltages). Virtual phase-to-phase voltage measurement channels can be used instead of the corresponding analog measurement channels. Voltage sag/swell/interruption measurement can be performed for one, two or three phases (at least one voltage measurement channel must be connected) Current measurement Currents can be measured with conventional current transformers or Rogowski coils. Current measurement can be performed for one, two or three phases (current measurement is optional). Measured currents are registered by the function block and can later be used e.g. in calculation of power loss caused by a voltage sag or an interruption Input/output configuration The measuring devices and signal types for the analog channels are selected and parameterized in a special dialog box of the graphic RECAP tool (IEC configuration tool). The binary inputs are parameterized in the same programming environment. The number of selectable analog inputs, binary inputs and binary outputs depends on the hardware used. When the analog channels and binary inputs have been selected and parameterized in the dialog box, the inputs and outputs of the function block can be configured in a graphic worksheet of the RECAP tool. The digital inputs 6

7 Distribution Automation PQVO3Sd are connected to the Boolean inputs of the function block. In the same way, the outputs of the function block are connected to the output signals. The voltage measurement channels are connected to the UL1_U12, UL2_U23 and UL3_U31 inputs of the function block. The following voltages can be connected to each input: Table 2. Input name UL1_U12 UL2_U23 UL3_U31 Measured voltage channels Measured voltage UL1, UL1b, U12, U12b, U12s or U12bs UL2, UL2b, U23, U23b, U23s or U23bs UL3, UL3b, U31, U31b, U31s or U31bs Note 1. The function block setting Declared voltage is set to % when phase-to-phase voltages are connected, and to 57.7% in case that phase-toground voltages are connected. This means that if a voltage different from nominal voltage is connected to the terminal, the setting Declared voltage is set to this voltage. Note 2. If the LV side voltages (e.g. U12b) are connected to the function block, then the LV side measurement of the phase currents must be used as well. Otherwise it is not possible to use recorded data, provided by the function block, for calculation of lost power. Note 3. True RMS measurement must be selected for voltage and current channels. 2.2 Rated frequency The rated frequency of the device is set via a dialog box in the configuration tool. In addition, the global control parameter Rated frequency of the relay can be used to read the rated frequency. 2.3 Measuring mode The function block measures true RMS voltage (includes harmonics etc.). The results are compared to nominal voltage or declared voltage. 2.4 Operation criteria The PQVO3Sd function block measures short duration voltage variations, i.e. voltage sags, swells and interruptions longer than 1 cycle (for interruptions1½ 7

8 PQVO3Sd Distribution Automation cycle) of the fundamental frequency (20 ms for 50 Hz and 16 ms for 60 Hz) and shorter than 60 s in voltage waveform. The maximum magnitude (in case of voltage swell) or depth (in case of voltage sag or interruption) and the duration of the event can be obtained by measuring the RMS value of the voltage for each phase. The maximum magnitude and depth is defined as a percentage value calculated from the difference between the nominal (or declared) and the measured voltage (e.g. 70 % depth means that the minimum magnitude of a sag event is 70 % of the nominal amplitude). The duration of each phase corresponds to the period during which the RMS values measured remain above or below the corresponding limit. Figure 2 illustrates the duration and magnitude limits of the function block. PQVO3Sd measures RMS values for voltage. When this measured RMS value drops below the sag limit, and in the same time remains above the interruption limit, a sag is detected. If the voltage drops below the interruption limit, an interruption is detected. When the measured RMS value rises above the swell limit, a swell is detected. Note 4. The function block setting Interrupt. limit must be set below the setting Sag limit for correct and standardized operation of the function block. Figure 2. Duration and voltage magnitude limits for swell, sag and interruption measurement If a voltage swell, sag or interruption is detected, the corresponding output signal (SWELL, SAG or INT) is set to the Boolean value TRUE. The output signal is TRUE during the swell, sag or interruption event. The outputs SWELL 8

9 Distribution Automation PQVO3Sd and SAG can be active in the same time in case of e.g. a single-phase earth fault (see Figure 7). 2.5 Outputs of the function block Swell 1. The SWELL output is set to TRUE when the voltage level of any phase rises above the swell limit (IEC ). 2. The SWELL output is set to FALSE when the voltage levels of all phases are equal to or below the swell limit (minus the hysteresis) or when the swell is active longer than the maximum duration. Figure 3. Three-phase swell (this voltage variation is considered as a valid event and is being recorded) 9

10 PQVO3Sd Distribution Automation Sag 1. The SAG output is set to TRUE when the voltage level on any phase drops below the sag limit (IEC ). 2. The SAG output is set to FALSE when the voltage levels of all phases are equal to or above the sag limit (plus the hysteresis) or when the sag is active longer than the maximum duration. Figure 4. Three-phase sag. Phase U2 (green) starts and phase U3 (blue) ends the event 10

11 Distribution Automation PQVO3Sd Interruption 1. The INT output is set to TRUE when the voltage levels of all phases drop below the interruption limit (IEC ). 2. The INT output is set to FALSE when the voltage level of any phase is equal to or above the interruption limit (plus the hysteresis), or when the interruption is active longer than the maximum duration. Figure 5. Three-phase interruption When only one or two phases are below the interruption limit, the event is regarded as a sag, and the SAG output is set to TRUE during the event (see Figure 6). 11

12 PQVO3Sd Distribution Automation Figure 6. One-phase interruption (event is regarded as a sag) 12

13 Distribution Automation PQVO3Sd Figure 7. Single-phase earth fault Note 5. If the voltage variation event is active longer than the maximum duration, the corresponding outputs are set to FALSE, as in Figure 8. Furthermore, the function block is disabled as long as the event remains active in order to prevent unnecessary indications. 13

14 PQVO3Sd Distribution Automation Figure 8. One-phase sag which duration is longer than setting Duration max Counters The SAG_COUNTER output indicates the sum of the detected valid (the event duration is between min and max duration) voltage sags since the last reset of the function block. The same functionality correspondingly applies for the SWELL_COUNTER and INT_COUNTER outputs. 14

15 Distribution Automation PQVO3Sd 2.6 Indications and events When the voltage level of any phase is below or above the corresponding limit, a start event (E1) is generated. An end event (E0) indicates ending of the particular event in case. If the measured duration of the detected event is between the minimum and maximum durations, it is considered as a valid voltage variation event and then the measurement values are recorded. This recording is indicated by the generation of the event E2, which is sent at the same time as event E0 (see Figure 3). A voltage variation detection is also indicated with a HMI text indication. Event sending can be seen in Figures 3-8. For more information see section Recorded Data. Note 6. The function block PQVO3Sd measures the duration of each voltage channel separately, but the duration settings (Duration min and Duration max) of the function block are compared to the total duration of the variation event. The event duration can be seen in Figure 6. This event duration determines whether the measurement values of the variation event are recorded or not. 2.7 Resetting The registers can be reset, either via the RESET input, over the serial bus or via the local HMI. The operation indicators, the counters and the recorded data can be reset as follows: Operation indicators Registers Counters RESET input of the function block 1) X X Parameter F514V013 1) X X General parameter F001V011 2) General parameter F001V012 2) General parameter F001V013 2) X X Push-button C 2) Push-buttons C + E (2 s) 2) Push-buttons C + E (5 s) 2) X X 1) Resets counters and recorded data of the particular function block. 2) Affects all function blocks. X X X X 15

16 PQVO3Sd Distribution Automation 2.8 Recorded Data General The information required for later power quality analysis is recorded when the function block has detected a valid voltage variation. The data of the last three events are stored into the registers Recorded data 1...3, beginning from Recorded data 1. These registers are updated in a cyclical manner, where the values of the most recent event overwrite the oldest recorded data. If recorded data has been reset or the relay has been restarted, first event is again stored to Recorded data 1. Date and time of variation start The time stamp for each of the 3 phases indicates the time instant at which the voltage variation event was detected. Date and time of min/max voltage value The time stamp for each of the 3 phases indicates the time instant at which the measured voltage was at a minimum/maximum during the measured power quality event. Type of voltage variation The type of the detected voltage variation event (swell/sag/interruption/ sag&swell). Magnitude (% of declared voltage) The minimum/maximum voltage value during the swell/sag/interruption for each of the 3 phases. Duration The duration of the swell/sag/interruption for each of the 3 phases. The measuring principle for duration measurement can be seen in Figure 6. Currents The measured currents preceding the start of swell/sag/interruption for each of the 3 phases. 16

17 Distribution Automation PQVO3Sd 2.9 Measurement accuracy In normal operating conditions, the voltage variation measurement accuracy is in accordance with the international standard IEC Duration measurement Measurement accuracy for duration measurement in normal operating conditions is: ± 1 fundamental frequency cycle (IEC Class A) Voltage and current measurement Measurement accuracies for voltage and current measurement are at normal operating conditions (IEC Class B): ± 1.0% of In (for current measurement) ± 1.0% of Un (for voltage measurement) 17

18 PQVO3Sd Distribution Automation 3. Parameters and Events 3.1 General Each function block has a specific channel number for serial communication parameters and events. The channel for PQVO3Sd is 514. The data direction of the parameters defines the use of each parameter as follows: Data direction R, R/M W R/W Description Read only Write only Read and write The different event mask parameters (see section Control Settings ) affect the visibility of events on the HMI or on the serial communication (LON or SPA) as follows: Event mask 1 (F514V101/102) Event mask 2 (F514V103/104) Event mask 3 (F514V105/106) Event mask 4 (F514V107/108) SPA / MMI (LON) LON LON LON For example, if only the events E3, E4 and E5 are to be seen on the HMI of the relay terminal, the event mask value 56 ( ) is written to the Event mask 1 parameter (F514V101). 18

19 Distribution Automation PQVO3Sd 3.2 Setting values Control Settings Parameter Code Values Unit Default Data Explanation direction Declared voltage V % R/W Declared input voltage Duration min V ms 10 R/W Minimum voltage variation duration Duration max V ms R/W Maximum voltage variation duration Swell limit V % R/W Swell threshold Sag limit V % 90.0 R/W Sag threshold Interrupt. limit V % 1.0 R/W Interruption threshold Reset registers V ) - 0 W Resetting of outputs and registers Event mask 1 V R/W Event mask for event transmission (E0... E2) Event mask 2 V R/W Event mask for event transmission (E0... E2) Event mask 3 V R/W Event mask for event transmission (E0... E2) Event mask 4 V R/W Event mask for event transmission (E0... E2) 1) Reset registers 0 = 0; 1 = Reset 19

20 PQVO3Sd Distribution Automation 3.3 Measurement values Input Data Parameter Code Values Unit Default Data direction Explanation UL1_U12 I x Un 0.00 R/M Phase-to-earth voltage UL1 or phase-to-phase voltage U12 UL2_U23 I x Un 0.00 R/M Phase-to-earth voltage UL2 or phase-to-phase voltage U23 UL3_U31 I x Un 0.00 R/M Phase-to-earth voltage UL3 or phase-to-phase voltage U31 IL1 I x In R/M Phase current IL1 IL2 I x In R/M Phase current IL2 IL3 I x In R/M Phase current IL Output Data Parameter Code Values Unit Default Data direction Explanation SWELL O ) - 0 R/M Swell in progress SAG O ) - 0 R/M Sag in progress INT O ) - 0 R/M Interruption in progress SWELL_COUNT O R/M Output indicating the amount of swells counted SAG_COUNT O R/M Output indicating the amount of sags counted INT_COUNT O R/M Output indicating the amount of interruptions counted 1) Active 0 = Not Active; 1 = Active 20

21 Distribution Automation PQVO3Sd Recorded data Recorded data 1 Parameter Code Values Unit Default Data Explanation direction Type V ) - 0 R/M Type of detected voltage variation event Start date U1 V202 YYYY-MM-DD - - R/M Event start date of phase 1 Start time U1 V203 hh:mm:ss.mss - - R/M Event start time of phase 1 Start date U2 V204 YYYY-MM-DD - - R/M Event start date of phase 2 Start time U2 V205 hh:mm:ss.mss - - R/M Event start time of phase 2 Start date U3 V206 YYYY-MM-DD - - R/M Event start date of phase 3 Start time U3 V207 hh:mm:ss.mss - - R/M Event start time of phase 3 Min/max date U1 V208 YYYY-MM-DD - - R/M Date of phase 1 min/max value measurement Min/max time U1 V209 hh:mm:ss.mss - - R/M Time of phase 1 min/max value measurement Min/max date U2 V210 YYYY-MM-DD - - R/M Date of phase 2 min/max value measurement Min/max time U2 V211 hh:mm:ss.mss - - R/M Time of phase 2 min/max value measurement Min/max date U3 V212 YYYY-MM-DD - - R/M Date of phase 3 min/max value measurement Min/max time U3 V213 hh:mm:ss.mss - - R/M Time of phase 3 min/max value measurement Duration 1 V ms 0 R/M Duration for phase 1 Duration 2 V ms 0 R/M Duration for phase 2 Duration 3 V ms 0 R/M Duration for phase 3 Mag. UL1_U12 V % 0.0 R/M Magnitude for phase 1 Mag. UL2_U23 V % 0.0 R/M Magnitude for phase 2 Mag. UL3_U31 V % 0.0 R/M Magnitude for phase 3 Current IL1 V x In R/M Phase current IL1 Current IL2 V x In R/M Phase current IL2 Current IL3 V x In R/M Phase current IL3 1) EVENT_TYPE 0 = Swell; 1 = Sag; 2 = Interruption; 3 = Sag&Swell 21

22 PQVO3Sd Distribution Automation Recorded data 2 Parameter Code Values Unit Default Data Explanation direction Type V ) - 0 R/M Type of detected voltage variation event Start date U1 V302 YYYY-MM-DD - - R/M Event start date of phase 1 Start time U1 V303 hh:mm:ss.mss - - R/M Event start time of phase 1 Start date U2 V304 YYYY-MM-DD - - R/M Event start date of phase 2 Start time U2 V305 hh:mm:ss.mss - - R/M Event start time of phase 2 Start date U3 V306 YYYY-MM-DD - - R/M Event start date of phase 3 Start time U3 V307 hh:mm:ss.mss - - R/M Event start time of phase 3 Min/max date U1 V308 YYYY-MM-DD - - R/M Date of phase 1 min/max value measurement Min/max time U1 V309 hh:mm:ss.mss - - R/M Time of phase 1 min/max value measurement Min/max date U2 V310 YYYY-MM-DD - - R/M Date of phase 2 min/max value measurement Min/max time U2 V311 hh:mm:ss.mss - - R/M Time of phase 2 min/max value measurement Min/max date U3 V312 YYYY-MM-DD - - R/M Date of phase 3 min/max value measurement Min/max time U3 V313 hh:mm:ss.mss - - R/M Time of phase 3 min/max value measurement Duration 1 V ms 0 R/M Duration for phase 1 Duration 2 V ms 0 R/M Duration for phase 2 Duration 3 V ms 0 R/M Duration for phase 3 Mag. UL1_U12 V % 0.0 R/M Magnitude for phase 1 Mag. UL2_U23 V % 0.0 R/M Magnitude for phase 2 Mag. UL3_U31 V % 0.0 R/M Magnitude for phase 3 Current IL1 V x In R/M Phase current IL1 Current IL2 V x In R/M Phase current IL2 Current IL3 V x In R/M Phase current IL3 1) EVENT_TYPE 0 = Swell; 1 = Sag; 2 = Interruption; 3 = Sag&Swell 22

23 Distribution Automation PQVO3Sd Recorded data 3 Parameter Code Values Unit Default Data Explanation direction Type V ) - 0 R/M Type of detected voltage variation event Start date U1 V402 YYYY-MM-DD - - R/M Event start date of phase 1 Start time U1 V403 hh:mm:ss.mss - - R/M Event start time of phase 1 Start date U2 V404 YYYY-MM-DD - - R/M Event start date of phase 2 Start time U2 V405 hh:mm:ss.mss - - R/M Event start time of phase 2 Start date U3 V406 YYYY-MM-DD - - R/M Event start date of phase 3 Start time U3 V407 hh:mm:ss.mss - - R/M Event start time of phase 3 Min/max date U1 V408 YYYY-MM-DD - - R/M Date of phase 1 min/max value measurement Min/max time U1 V409 hh:mm:ss.mss - - R/M Time of phase 1 min/max value measurement Min/max date U2 V410 YYYY-MM-DD - - R/M Date of phase 2 min/max value measurement Min/max time U2 V411 hh:mm:ss.mss - - R/M Time of phase 2 min/max value measurement Min/max date U3 V412 YYYY-MM-DD - - R/M Date of phase 3 min/max value measurement Min/max time U3 V413 hh:mm:ss.mss - - R/M Time of phase 3 min/max value measurement Duration 1 V ms 0 R/M Duration for phase 1 Duration 2 V ms 0 R/M Duration for phase 2 Duration 3 V ms 0 R/M Duration for phase 3 Mag. UL1_U12 V % 0.0 R/M Magnitude for phase 1 Mag. UL2_U23 V % 0.0 R/M Magnitude for phase 2 Mag. UL3_U31 V % 0.0 R/M Magnitude for phase 3 Current IL1 V x In R/M Phase current IL1 Current IL2 V x In R/M Phase current IL2 Current IL3 V x In R/M Phase current IL3 1) EVENT_TYPE 0 = Swell; 1 = Sag; 2 = Interruption; 3 = Sag&Swell Events Code Weighting coefficient Default mask Event reason Event state E0 1 1 Voltage variation start Reset E1 2 1 Voltage variation start Activated E2 4 1 Meas. values registered Ready 23

24 PQVO3Sd Distribution Automation 4. Technical Data Reset ratio Typ Configuration data Task execution interval (Relay Configuration Tool): 10 ms at the rated frequency f n = 50 Hz 24