Capacitor/Filter-Protection Relay CPR 04

Transcription

1 Capacitor/Filter-Protection Relay CPR 04

2 Capacitor/Filterprotection Relay CPR 04 Introduction The Trench CPR 04 is a comprehensive, numeric protection relay, featuring: Compact draw-out design Panel or 19 inch rack mounting Four software configurable measuring elements Five configurable output relays One self-supervision output relay Operating mode software selectable (NORMAL / H-BRIDGE) RS232 serial data port at the front Software selectable RS232 or RS485 serial data port at the rear Time stamping function for trip history and setting menu Application The CPR 04 provides comprehensive protection for the capacitive, inductive and resistive elements of three phase medium and high voltage shunt capacitor banks and harmonic filter circuits. The capacitor banks may have a single star, double star, delta or H configuration, with internally fused, externally fused or unfused capacitor units. User configurable, to cater for a wide range of relay settings A high performance protection relay for capacitor banks and harmonic filter circuits 2

3 NORMAL MODE - Protective functions Peak repetitive overvoltage protection For each phase, CPR 04 determines the peak repetitive capacitor voltage using advanced Digital Signal Processor (DSP) techniques, by integrating the measured line current waveform, to give a signal representing the voltage waveform applied to the capacitor bank. The peak repetitive voltage of this signal is then extracted, and compared to adjustable thresholds. For calculated peak repetitive voltages above the thresholds, a starter signal is output, and the inverse time ANSI capacitor temporary overvoltage withstand curve respectively adjustable definite timers define the time before trip signals are output. Thermal overcurrent protection For each phase, CPR 04 protects a capacitor bank / harmonic filter circuit from excess thermal current stressing, by modelling the thermal response of the circuit to the rms heating current, Irms. A second order thermal model and associated adjustable heating / cooling time constant is then used to continuously calculate the thermal current response lth, to the rms heating current. Ith is compared to adjustable thresholds, which are linked to adjustable definite timers. Trip signals are output, if the associated threshold is exceeded for the definite time set. Star point unbalance protection CPR 04 measures the star point unbalance current, and calculates the fundamental frequency component, Iub. This can then be compensated, in magnitude and phase angle to zero, to enable detection of further changes, in both magnitude and phase angle, ( Iub). The magnitude is a measure of the change in capacitance in any leg of a double star capacitor bank arrangement, whereas the phase angle indicates the leg in which the change in capacitance has occurred. The magnitude of ( )Iub is continuously compared with adjustable thresholds, each with an adjustable definite timer. Trip signals are output, if the associated thresholds are exceeded for the definite times set. Line current unbalance protection The monitoring of line current unbalance provides a means of detecting changes in impedance resulting from failures and faults within the capacitor bank / harmonic filter circuit. These faults or failures invariably result in an unbalance in the fundamental frequency component of the line currents. CPR 04 calculates the fundamental frequency line current unbalance, Ilub, from the three phase line currents. Ilub is continuously compared with adjustable thresholds each with an adjustable definite timer. Trip signals are output if the associated thresholds are exceeded for the definite times set. The sensitivity of line current unbalance protection is limited by the effect of supply voltage unbalance on the line currents. Nevertheless, line current unbalance protection is useful as back-up protection to star point unbalance protection. 3

4 NORMAL MODE - Protective functions 4 Earth fault protection CPR 04 calculates the fundamental frequency earth fault current, Io, as the magnitude of the vector sum of the three phase line currents. Io is compared with adjustable thresholds each with an adjustable definite timer. Trip signals are output, if the associated thresholds are exceeded for the definite times set. Fundamental frequency overcurrent protection For each phase, CPR 04 calculates the fundamental frequency component, I1, of the line current. I1 is continuously compared with adjustable thresholds each with an adjustable definite timer. Trip signals are output, if the associated thresholds are exceeded for the definite times set. RMS - overcurrent protection For each phase, CPR 04 calculates the rms current, Irms, (fundamental + harmonics up to the 50th). Irms is continuously compared with adjustable thresholds each with an adjustable definite timer. Trip signals are output if the associated thresholds are exceeded for the definite times set. Undercurrent protection For each phase, CPR 04 calculates I1, the fundamental frequency component of the line current. I1 is continuously compared with an adjustable undercurrent threshold, I1<, with an associated adjustable definite timer. With the capacitorbank / harmonic filter circuit breaker on, if the mains power supply fails, as indicated by a drop in I1 below I1< for longer than the definite time set, then the undercurrent trip signal is output. Breaker fail protection If I1 remains above the undercurrent threshold for longer than the adjustable definite time after the breaker switches off, or after a trip output signal has been given by CPR 04, then this indicates a failure of the breaker, and the breaker fail signal is output. This signal can be used trip to an up-stream breaker. Capacitor bank discharge timer CPR 04 provides the necessary logic, and a breaker inhibit output signal, Bena, to inhibit the re-energization of the capacitor bank / harmonic filter circuit breaker, for an adjustable definite time since de-energization Event Trip CPR 04 provides the necessary logic, to trip any of the output relays via a change in the status of the digital input.

5 H-BRIDGE MODE - Protective function H configuration capacitor bank unbalance protection In an alternative user-configurable operating mode, CPR 04 provides fundamental frequency H configuration capacitor bank unbalance protection only. This provides sensitive unbalance protection independently for each phase of a capacitor bank. For each phase the CPR04 calculates the fundamental component of the measured unbalance current. The natural unbalance of each phase can then be compensated in amplitude and phase angle, to detect subsequent changes. ( a/b/c lub) The unbalance current ( )a/b/c lub is then compared to adjustable thresholds, each with an adjustable timer. Trip signals are output, if the thresholds are exceeded for the definite times set. 5

6 Relay design 6 Measuring elements Four current measuring elements are provided within CPR 04. The nominal current (1A/5A) can be set in the menu. Relay outputs CPR 04 has six output relays. The functionality of output relays 1 to 5 is user configurable. The user may program the relays to be manual or selfresetting, and to be normally energized or de-energized during the power-up healthy condition. In addition, the user may direct any of the binary output signals of the protective functions to output relays 1 to 5. Output relay 6 is the self-supervision relay for CPR 04, and is energized in the power-up, normal condition, and de-energizes on loss of auxiliary power supply, or on failure of CPR 04 internal power supply, microprocessor hardware, software or memory. Contact forms Output relays 1 to 6 each have one change-over contact. As default, all output relays are supplied with the normally open (relay de-energized) contacts wired to the terminal block. However, the user can easily change the contacts of the output relays to be as required by the application. Auxiliary power supply A high efficiency, low loss, wide range AC/DC auxiliary power supply is provided within CPR 04. Special care has been taken to minimize the overall standing load of CPR 04 on the DC station batteries or AC busbar voltage supply. The CPR 04 nominal auxiliary power supply voltage is V ac/dc. For the operative range see technical specifications, page 10. Time stamping CPR04 features a built in real time clock which allows to time and date stamp trip events as well as modifications to settings and status registers. The clock is backed up by a maintenance free supercap. Serial data port CPR 04 is provided with a RS232 frontport and a softwareselectable RS232 or RS485 serial data port at the rear for data communications between an intelligent host device and the protection relay. The RS232 port at the front also allows for future firmware upgrades as additional functions and features might be added. The serial data port can be used for the following purposes: Downloading of a set-up file to a CPR 04. Uploading from a CPR 04 of the set-up file currently active within the relay. Uploading from a CPR 04 of any error codes, or alarm and trip annunciation messages. The uploading from a CPR 04 of various instantaneous parameters, measured and calculated by the relay during normal operation. Interconnection into a SCADA system using MODBUS RTU protocol

7 Relay design LED indicators Three LED indicators are provided on the front panel of CPR 04, as follows: Green LED: This indicates that the auxiliary power supply is on, and the self-supervision output relay is energized, indicating that the protection relay is healthy. Yellow LED: This indicates that one (or more) of the starter binary outputs signals of a protection function is (are) at logic 1 (high), and that the protection relay may trip if the condition persists. Red LED: This indicates that a trip condition has occurred that has not yet been reset and / or acknowledged. LCD display A two line, 16 character, full alpha-numeric, back-lit, Liquid Crystal Display (LCD) is provided on the front panel of CPR 04 for the following purposes: During normal operation: The display of various measured and calculated parameters, together with the low-set thresholds associated with these parameters. After a relay trip condition: Annunciation of all the fault conditions after a trip, including the value of the fault currents and voltages at the instant of trip, and the relay trip time after occurance of the fault condition. During relay configuration and normal operation: Display of the current and voltage thresholds and timer settings for each element, and display of each output relay configuration and check-sum. During relay configuration: Interactive configuration of the protection relay During testing: Interactive self testing of the protection relay After failure: Annunciation of any protection relay hardware, software or memory failures detected during self-testing of the protection, by display of the relevant error codes. Test facilities While CPR 04 is in service, it continuously performs various self-testing functions, and if any errors or failures are detected, the corresponding error code(s) will be displayed, and the self-supervision output relay will de-energize, to signal the malfunction. These selftests include tests of the microprocessor, RAM, ROM and EEPROM. In addition, a further set of hardware diagnostic tests may be performed on the protection relay by the user, to test and check the functionality of the measurement offsets for elements 1 to 4, the digital input, relay outputs, keypad, LCD display and LEDs. 7

8 Relay design Housing and terminals CPR 04 is housed in a draw-out chassis within a fixed case. This housing is particularly suitable for both flush mounting and 19 inch rack mounting. The case is designed for indoor use in tropical climate and is designed to withstand shock, vibration and the ingress of dust and moisture. A terminal block, with 28 recessed terminals, is provided on the fixed case. Standard screw terminals, or fast-on connectors, can be used on the terminal block, for the external connections to the protection relay. PC based software package A Windows based software package is available for CPR 04 to exploit its communication facilities. This software package enables the user to create, edit, save, open and print any number of CPR 04 set-up files on a PC, and to download or upload a set-up file to or from a CPR 04, either directly or via MODEM. In addition, all the other facilities and functions of the serial data port, as detailed above, can be exploited using this software package. Digital input CPR 04 is provided with an optically isolated, binary (on / off), voltage input channel. Any voltage from V AC/DC applied to this input channel will signal that the input is active. The functionality of the digital input is depending on the setting in the relevant menu. Withdrawing the protection relay module automatically short circuits the current transformer terminals. Keypad A five button key-pad is provided on the front panel of CPR 04 for the following purposes: Interactive configuration of the protection relay Acknowledgment and resetting of trip conditions 8 Hardware diagnostic testing

9 General characteristics Applicable standard IEC and EN Operating temperature range -10 to +55 C to IEC Storage temperature range -20 to +70 C to IEC Humidity 4 days, 95% RH, with temperature cycled between +25 O C and + 45 O C, to IEC Enclosure degree of protection IP50 to IEC Shock and bump Shock: 15g, 3 pulses per direction, per axis. (total 18 times). Bump : 10g, 1000 pulses per direction, per axis (total 6000 times). To IEC Vibration 9,8ms -2 (1g) constant frequency from 10 to 150 Hz per axis. To IEC Power frequency voltage withstand 2 kv rms 50 Hz for 1 minute, from all terminals to case (earth), and between terminals of independent circuits. 1,5 kv rms across open contacts of output relays. To IEC Impulse voltage withstand 5 kv peak, 1,2/50 µs waveshape, 0,5 J energy content, 10 shots in each polarity, between all terminals and case (earth), and between terminals of independent circuits. To IEC Insulation resistance 50 MΩ minimum at 500 VDC, to IEC Immunity to high frequency 2,5 kv peak between independent circuits, and to case (earth). disturbances 1 kv peak across terminals of the same circuit. (1MHz burst disturbance test) To IEC Immunity to electrostatic 8 kv discharge in air discharges 6 kv point contact discharge (Electrostatic discharge test) To IEC and EN Immunity to fast transient bursts 4kV supply lines / 2kV input & output lines / (Fast transient burst test) 1kV communication lines To IEC and EN Immunity to high frequency 10 V / m, 100% PM, at 900 MHz electromagnetic fields 10 V, 80% AM, from 150 khz to 80 MHz as well as 10 V / m, 80% AM, from 80 MHz to 1000 MHz, to EN Immunity to surge voltages 2kV peak common / 1kV peak differential To EN and EN Immunity to voltage interruptions 230 VAC 100% interruption 200ms 110 VDC 100% interruption 50ms To EN Harmonics and flicker of main current To EN Conducted emissions To EN 50263, from 150 khz to 30 MHz. Radiated emissions To EN 50263, from 30 MHz to 1000 MHz. Nett Mass 3 kg Overall dimensions 103(w) x 177(h) x 248(d) 9

10 Technical specifications Measuring Quantity 4 elements Nominal rated current, In 1A or 5A selectable in the software Continuous current 15A Short time current 300A for 1s Burden <40mΩ Accuracy of measurement +/- 2% of nominal rated current Auxiliary power Nominal rated voltage, Vx V AC / DC supply Operative range AC / DC V AC / V DC Burden with DC supply <14W with all relays and back-light ON Burden with AC supply <24VA with all relays and back-light ON Output relays Quantity Alarm / trip relays: 5 Self-supervision relay: 1 Contact form (per relay) 1 changeover contact (form C), user configurable as N/O or N/C Load Resistive load: Inductive load: (cos = 1) (cos = 0,4 L/R = 7 ms) K1 Rated load 5A at 250 VAC 3,5A at 250 VAC 1A at 220 VDC 0,8A at 220 VDC 3A at 110 VDC 2A at 110 VDC 5A at 48 VDC 4A at 48 VDC Max. operating voltage 380VAC, 250 VDC K2, K3, K4, K5, K6 Rated load 5A at 250 VAC 3,5A at 250 VAC 5A at 30 VDC 2,5A at 30 VDC Rated carry current 5A Max. operating voltage 380VAC, 125 VDC Min. permissible load 100mA at 5 VDC Digital input Quantity 1 channel Function Breaker on; Remote reset; Event trip Isolation Optically isolated Type V AC / DC voltage input Pushbuttons Function >, <, ^,, and ACCEPT (red) Type Miniature spring loaded manual pushbuttons Display Type Back-lit Liquid Crystal Display (LCD), with full alpha-numeric character set Screen Size 16 character x 2 line Character height 4mm Indicators Type Light Emitting Diodes (LEDs) Function Green : POWER ON / HEALTHY Yellow : START (ALARM) Red : TRIP Serial data port Quantity 2 Isolation Optically isolated Frontport type RS232 via DB9 socket Rearport type RS232 or RS485 selectable in the software Baudrate (kbd) 2.4 up to for each port seperatly selectable Real Time Clock Functionality Date; Weekday; HH:MM:SS Accuracy +/- 30 s per month Backup Supercap (>14 days without power) ^ 10

11 Block diagram 11

12 Trench Austria GmbH Paschinger Straße 49 AT-4060 Linz-Leonding/Austria Phone Fax Trench Brasil LTDA Via Expressa de Contagem, 2685 CEP Contagem, Minas Gerais/Brasil Phone Fax Trench China Limited 3658 Jiang Cheng Road Minhang, Shanghai P.R. China Phone Fax Trench France S.A. 16, rue du Général Cassagnou B.P. 70 FR St-Louis/France Phone Fax Trench Germany GmbH Nürnberger Straße 199 DE Bamberg/Germany Phone Fax Trench Italia S.r.l. Strada Curagnata 37 IT Cairo-Montenotte/Italy Phone Fax Trench Limited Coil Product Division 71 Maybrook Drive, Scarborough Ontario, Canada M1V 4B6 Phone Fax Trench Limited Instrument Transformer Division 390 Midwest Road, Scarborough Ontario, Canada M1P 3B5 Phone Fax Trench Switzerland AG Lehenmattstraße 353 CH-4052 Basel/Switzerland Phone Fax ema il Änderungen vorbehalten E 647 Trench (UK) Limited South Drive Hebburn Tyne & Wear NE31 1UW, Great Britain Phone Fax sales.uk@trench-group.com