ALPS. Advanced Line Protection System

Transcription

1 ALPS Advanced Line Protection System

2 Modified Fourier Calculation High Speed Sampling Phaselet Calculation Variable Window Digital Mimic 2

3 10 5 EXECUTE PHASELET CALCULATION AND PROTECTION ALGORITHMS High Speed Sampling # 1 # 2 # 3 # 4 16 SAMPLES # 5 # 6 # 7 # 8 32 SAMPLES # 9 #

4 Discrete Fourier Transform vt () = V cos( ωt+ φ) peak Vreal N 1 2 k = ( ) [ Vk cos( 2 π )] N N k = 0 Vimag N 1 2 k = ( ) [ Vk sin( 2 π )] N N k = 0 4

5 Full Cycle Fourier Transform WINDOW 1 WINDOW 2 WINDOW

6 Phaselet Definition Phaselets are partial sums of the products of the waveform samples and the sine/cosine coefficients. Input signals are sampled 64 times per cycle; protection algorithms are executed 16 times per cycle. Groups of phaselets may be added together and transformed to create a phasor. 6

7 Phaselet Calculation Phaselet Real = C X PhaseletImaginary = S X Where : C, S k p pp k k= + pp P 1 p pp k k= + pp P 1 = Sine and Cosine Coefficients p = phaselet index: there are N / P phaselets per cycle P = the number of phaselets per cycle X = kth sample of the input signal k k k k 7

8 10 5 EXECUTE PHASELET CALCULATION AND PROTECTION ALGORITHMS Variable Window # 1 # 2 # 3 # 4 16 SAMPLES # 5 # 6 # 7 # 8 32 SAMPLES # 9 #

9 Phasor Calculation Phaselets are converted to phasors by the following: Phasor Re al n Phasor Im aginary n TRR ( nw, ) TRI ( n, W) PhasorSum Re al n = TIR ( n, W) TII ( n, W) PhasorSum Im aginary n Where: PhaseletSumReal = Phaselet Real n n p= n W + 1 P PhaseletSumImaginary = Phaselet Imaginary n n p= n W +1 P n = Phasor index (N/P) W = Window size in samples p p 9

10 Phasor Calculation For a one cycle window, the Fourier calculation becomes: Phasor Re al n 2 n = N p n N = + 1 P Phaselet Re al p Phasor Im aginary n 2 n = N p n N = + 1 P Phaselet Im aginary p 10

11 Variable Window Fourier Transform 15 VARIABLE WINDOW 10 5 PRE-FAULT ONE CYCLE WINDOW

12 Mimic Algorithm Time Domain: IZ() t = I() t R + d (()) It dt L Sampled Data: δ ( Ik ( + δ) + Ik ( )) ( IZ( k ) R Ik ( + δ) Ik ( )) + = + L 2 2 δ 12

13 EXAMPLES OF ADAPTIVE PROTECTION ALGORITHMS 13

14 Adaptive Polarizing Memory Remote line end three phase faults: ZS ZL 3 PH ZS = 19 ZL Vr = 0.05 Rated Reverse zero voltage faults: Vr = 0 3 PH 14

15 Adaptive Polarizing Memory Extend memory time if: Voltage at the relay is less than 10% of rated. AND Any distance measuring function is picked up. 15

16 Adaptive Polarizing Memory Reset memory if: Voltage at the relay is greater than 10% of rated. AND Distance measuring function resets. 16

17 Variable Reach Zone 1 Z LINE FINAL REACH INITIAL REACH 17

18 Variable Reach Zone 1 Zone 1 reach is set to 90 % of ZL. WINDOW SIZE % OF SET REACH 1/16 Cycle 0 (can not operate) 1/8 Cycle 33% 3/16 Cycle 65% 1/4 Cycle 75% 5/16 Cycle 83% 1/2 Cycle 90% > 1/2 Cycle 100% 18

19 Adaptive Reactive Unit Supervision Reactance type distance functions require supervision to prevent operation on normal load flow. The traditional approach is to use a fixed resistive blinder, or a fixed reach mho function. 19

20 Adaptive Reactive Unit Supervision Adaptive mho Fixed mho Fixed Blinder X - ZL min Adaptive Blinder Reactance Unit X' - ZL max 20

21 EVALUATION OF DISTANCE RELAY OPERATING SPEED 21

22 Modeled System Protected Line Z1 = deg Z0 = deg Parallel Line Z1S = deg Z0S = deg Z1S = deg Z0S = deg 22

23 PC Simulation Trip Times Time (ms) % of Line 23

24 MPS Test Results Time (ms) % of Line 24

25 The ALPS Advanced Line Protection System gives you the protection choices you need. Whether you re protecting compensated or uncompensated lines; require single phase tripping or three phase tripping, with or without reclosing, its available. 25

26 APPLICATION Providing complete transmission line protection, ALPS is a multi-function digital protective relay system intended to provide distance protection for HV or EHV transmission lines. Distance protection for EHV lines Series compensated lines High speed tripping (half cycle) Single and three phase tripping 26

27 Single Line Diagram 27

28 PROTECTION Four zones of distance protection Pilot protection, step distance backup Out of step blocking and tripping Phase instantaneous overcurrent Ground instantaneous overcurrent Ground time overcurrent backup Over and under voltage functions 28

29 CONTROL Optional four shot recloser Configurable inputs and outputs Fully configurable relay logic 29

30 INPUTS/OUTPUTS All contact converter inputs and all contact outputs (except for alarms) in ALPS are configurable by the user. 8 configurable inputs, or 12 for single phase tripping 15 configurable outputs, or 20 for single phase tripping 30

31 RMS METERING Current (I a, I b, I c, I n ) Voltage (V a, V b, V c ) Watts (3 phase) Vars (3 phase) Frequency 31

32 fault location provided by a single ended fault location algorithm trip circuit monitor self test diagnostics event reporting of last 100 events fault reports high resolution oscillography MONITORING 32

33 USER INTERFACE 20 button keypad and 4 line LCD display RS232 serial port on front of unit RS232 and RS485 ports on rear of unit communication software IRIG-B input for time synchronization 33