SELF DAMPING TEST ON 1020 KCMIL ACCC/TW CONDUCTOR FOR COMPOSITE TECHNOLOGY CORPORATION

Transcription

1 To: Dave Bryant Composite Technology Corporation 2026 McGaw Avenue Irvine, CA USA SELF DAMPING TEST ON 1020 KCMIL ACCC/TW CONDUCTOR FOR COMPOSITE TECHNOLOGY CORPORATION Kinectrics North America Inc. Report No.: October 15, 2004 Michael Kastelein Transmission and Distribution Technologies Department 1.0 INTRODUCTION A Self-Damping Test was performed on an Aluminum Conductor, Composite Core Trapezoidal Wires (ACCC/TW) conductor for Composite Technology Corporation (CTC). The conductor is 1020 kcmil with an outside diameter of 28.1 mm (1.108 inch). There are 24 aluminum trapezoidal wires stranded in 2 layers over a single composite fiberglass/carbon fiber core. The specification for the conductor is contained in Appendix A. A 795 kcmil, 28.1 mm (1.108 inch), Drake ACSR conductor with round wires was also tested. The testing was conducted April 20-23, 2004 by Kinectrics North America Inc. personnel at 800 Kipling Avenue, Toronto, Ontario, M8Z 6C4, Canada. Important Note: This report documents the results of Self Damping Tests performed on 1020 kcmil ACCC/TW conductor and 795 kcmil ACSR conductor. The reader should be aware that the aluminum wires are fully annealed, trapezoidallyshaped for the ACCC conductor and are hard drawn, round-shaped for the ACSR conductor. This difference has significant influence on the self-damping characteristics of the conductors. The differences are mostly a function of the shape of the aluminum wires. The core material has less influence on self-damping the conductor than the aluminum wires. The reader is cautioned that, although the results are presented together, direct comparisons should not be made and that interpretations of the self damping characteristics of each conductor should be made in the proper context. PRIVATE INFORMATION Contents of this report shall not be disclosed without authority of the client. Kinectrics North America Inc., 800 Kipling Avenue, Toronto, Ontario M8Z 6C4.

2 2.0 PURPOSE OF TEST The purpose of the Self Damping Test is to measure the power dissipation characteristics of overhead conductors. The data are used to assist in the selection of aeolian vibration dampers for the cable. 3.0 TEST SET-UP The logarithmic decay method was used to perform these tests. The method is described in IEEE Std , IEEE Std and the Transmission Line Reference Book Wind- Induced Conductor Motion, EPRI The general arrangement used for the self damping test is shown in Figure 1. The test was carried out in a temperature-controlled laboratory at 22ºC ± 2ºC. The conductor was tensioned using a cantilever weight arm at one end and a hydraulic cylinder at the other end. A load-cell was placed between the hydraulic cylinder and the deadend to measure the tension in the conductor. The hydraulic cylinder was used to set the initial tension and the weight arm maintained the tension throughout the test. The conductor length between deadend clamps was approximately 32 m (105 ft). The conductor was rigidly clamped to intermediate abutments using square-faced clamps approximately the same diameter as the conductor. The clamping arrangement minimized the loss of vibration energy from of the span. An electromagnetic shaker was positioned near one end on the test span. A function generator providing a sinusoidal output controlled the electromagnetic shaker. An accelerometer measured the freeloop vibration amplitude of the conductor at mid-span. A quick release mechanism was used to detach the conductor from the shaker with minimal disturbances. A digital acquisition system recorded the output from the accelerometer. The calibratable instruments used in the test are listed in Appendix B. 4.0 TEST PROCEDURE Data Collection The conductors were tested at 5 tensions: 15, 20, 25, 30, and 40 percent of the conductor s rated breaking strength (RTS). The conductor was tested several different frequencies. The frequencies tested were the closest test span resonance to the frequencies that are generated in the wind velocity range from km/hr ( mph). The relationship between frequency, wind velocity and conductor diameter is: f(hz) = 50 X wind velocity (km/hr) / conductor diameter (mm) The phase angle between the force signal and the accelerometer s signal was used to indicate when the conductor was at a resonant frequency. After the conductor had stabilized at the resonance for a few minutes the shaker was disconnected. The signal from the accelerometer was integrated in its amplifier so that the output of the amplifier is proportional to velocity. The velocity signal was recorded by a digital data acquisition system while the vibration of the conductor decayed. 2

3 Data Reduction The decay of the free loop velocity (Figure 2) from the test condition at the 25% RTS and Hz is shown in Figure 2. This trace is used to illustrate the response of the conductor after being released from the shaker. The trace shows the envelope of the natural decay of the sinusoidal vibrations. Other test conditions decay at longer or shorter rates. A curve is fitted through the peak values of each cycle in the decay and is used to filter out small disturbances. The resulting fitted curve for the test condition in Figure 2 is shown in Figure 3. The peak-topeak amplitude, Y, of the conductor was calculated from the peak velocity, V. where Y = 1000*V / (π f) Y = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) f = frequency (Hz) The decay of the conductor was calculated from the equation of the fitted curve and is expressed in terms of logarithmic decrement. where: δ = 1/n ln(y o /Y n ) δ = log decrement n = number of cycles Y o = peak-to-peak amplitude (mm) Y n = peak-to-peak amplitude at n cycles after Y o (mm) The power dissipated by the conductor s self-damping is calculated by: where: P = ½ f m V o 2 δ P = power dissipated (watts per metre) f = frequency (Hz) m = mass per unit length of the conductor (kg/m) V o = peak loop velocity at amplitude Y o (m/sec) δ = log decrement The power dissipation is plotted as Power versus Normalized Amplitude where: Normalized Amplitude = Y/D where Y = average peak-to-peak amplitude between Y o and Y n = (Y o + Y n )/2 D = conductor diameter (mm) 3

4 5.0 TEST RESULTS Tables 1 to 5 show the data collected for the tests at 15, 20, 25, 30, and 40 percent RTS, respectively. Not all data are reported in the tables in order to make them a manageable size. Figures 4 to 8 show the graphs of the conductor s power dissipation characteristics at 15, 20, 25, 30, and 40 percent RTS, respectively. The self damping of this conductor at 15% and 20% was too high to tune the vibration to a natural frequency for frequencies above 20 Hz and 25Hz, respectively. Only natural frequencies that could locked-in are analyzed. The self damping data for the 795 kcmil, Drake ACSR round wire conductor are plotted in red on Figures 1,3 and 5 for 15%, 25% and 40% RTS. The ACSR round wire conductor has a lower self-damping than the ACCC/TW. Higher self-damping is a benefit of all trapezoidalshaped wire conductors compared to round wire conductors. This is true irrespective of the construction of the core of the conductor. Prepared by: Michael Kastelein Technical Specialist Transmission and Distribution Technologies Department Reviewed by: C.J. Pon Principal Engineer Transmission and Distribution Technologies Department Approved by: Dr. J. Kuffel General Manager Transmission and Distribution Technologies Department MK:JC DISCLAIMER Kinectrics North America Inc., has prepared this report in accordance with, and subject to, the terms and conditions of the contract between Kinectrics North America Inc. and Composite Technology Corporation. Kinectrics North America Inc.,

5 Table 1 Self Damping Data for CTC ACCC/TW 1020 kcmil Conductor at 15% RTS Conductor: CTC ACCC/TW, 1020 kcmil Diameter: 28.1 mm (1.108 inch) Grease: Normal Manufacturing Alum. Strands: Trapezoidal, 2 layers, 24 strands Test Span: 32 m (105 ft) Mass/Length: kgf/m (0.957 lbf/ft) Test Tension: 3048 kgf (6720 lbf) Condition: New 15% RTS Frequency Loop Length Y o V Y n n P Y/D (hz) (m) (mm) (m/s) (mm) (cycles) (mw/m) Notes: Y o = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) Y n = peak-to-peak amplitude at n cycles after Y o (mm) P = power dissipated (mw/m) Y/D = normalized amplitude = (Y o + Y n )/2 The power dissipation characteristics for the ACCC/TW 1020 kcmil conductor at 15% RTS is plotted as Power Dissipated, P, versus Normalized Amplitude, Y/D, and is shown in Figure 4. 5

6 Table 2 Self Damping Data for CTC ACCC/TW 1020 kcmil Conductor at 20% RTS Conductor: CTC ACCC/TW, 1020 kcmil Diameter: 28.1 mm (1.108 inch) Grease: Normal Manufacturing Alum. Strands: Trapezoidal, 2 layers, 24 strands Test span: 32 m (105 ft) Mass/Length: kgf/m (0.957 lbf/ft) Test Tension: 4064 kgf (8959 lbf) Condition: New 20% RTS Frequency Loop Length Y o V Y n n P Y/D (hz) (m) (mm) (m/s) (mm) (cycles) (mw/m) Notes: Y o = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) Y n = peak-to-peak amplitude at n cycles after Y o (mm) P = power dissipated (mw/m) Y/D = normalized amplitude = (Y o + Y n )/2 The power dissipation characteristics for the ACCC/TW 1020 kcmil conductor at 20% RTS is plotted as Power Dissipated, P, versus Normalized Amplitude, Y/D, and is shown in Figure 5. 6

7 Table 3 Self Damping Data for CTC ACCC/TW 1020 kcmil Conductor at 25% RTS Conductor: CTC ACCC/TW, 1020 kcmil Diameter: 28.1 mm (1.108 inch) Grease: Normal Manufacturing Alum. Strands: Trapezoidal, 2 layers, 24 strands Test span: 32 m (105 ft) Mass/Length: kgf/m (0.957 lbf/ft) Test Tension: 5080 kgf (11199 lbf) Condition: New 25%RTS Frequency Loop Length Y o V Y n n P Y/D (hz) (m) (mm) (m/s) (mm) (cycles) (mw/m) Notes: Y o = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) Y n = peak-to-peak amplitude at n cycles after Y o (mm) P = power dissipated (mw/m) Y/D = normalized amplitude = (Y o + Y n )/2 The power dissipation characteristics for the ACCC/TW 1020 kcmil conductor at 25% RTS is plotted as Power Dissipated, P, versus Normalized Amplitude, Y/D, and is shown in Figure 6. 7

8 Table 4 Self Damping Data for CTC ACCC/TW 1020 kcmil Conductor at 30% RTS Conductor: CTC ACCC/TW, 1020 kcmil Diameter: 28.1 mm (1.108 inch) Grease: Normal Manufacturing Alum. Strands: Trapezoidal, 2 layers, 24 strands Test Span: 32 m (105 ft) Mass/Length: kgf/m (0.957 lbf/ft) Test Tension: 6096 kgf (13439 lbf) Condition: New 30% RTS Frequency Loop Length Yo V Yn n P Y/D (hz) (m) (mm) (m/s) (mm) (cycles) (mw/m) Notes: Y o = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) Y n = peak-to-peak amplitude at n cycles after Y o (mm) P = power dissipated (mw/m) Y/D = normalized amplitude = (Y o + Y n )/2 The power dissipation characteristics for the ACCC/TW 1020 kcmil conductor at 30% RTS is plotted as Power Dissipated, P, versus Normalized Amplitude, Y/D, and is shown in Figure 7. 8

9 Table 5 Self Damping Data for CTC ACCC/TW 1020 kcmil Conductor at 40% RTS Conductor: CTC ACCC/TW, 1020 kcmil Diameter: 28.1 mm (1.108 inch) Grease: Normal Manufacturing Alum. Strands: Trapezoidal, 2 layers, 24 strands Test Span: 32 m (105 ft) Mass/Length: kgf/m (0.957 lbf/ft) Test Tension: 8128 kgf (17919lbf) Condition: New 40% RTS Frequency Loop Length Y o V Y n n P Y/D (hz) (m) (mm) (m/s) (mm) (cycles) (mw/m) Notes: Y o = peak-to-peak amplitude (mm) V = peak free loop velocity (m/sec) Y n = peak-to-peak amplitude at n cycles after Y o (mm) P = power dissipated (mw/m) Y/D = normalized amplitude = (Y o + Y n )/2 The power dissipation characteristics for the ACCC/TW 1020 kcmil conductor at 40% RTS is plotted as Power Dissipated, P, versus Normalized Amplitude, Y/D, and is shown in Figure 8. 9

10 Hydraulic Ram Deadend Assembly Load Cell Clamp Electromagnitic Shaker Accelerometer Clamp Cantelever Weight Arm 8 10 #REPORTNUMBER Figure 1: Set-up of Self-Damping Test

11 Velocity - m/s Time - Seconds Figure 2 Typical Decay Trace Conductor at 25% RTS, 7 Vibration Loops, Hz 0.6 Peak Velocity - m/s Time - Seconds Figure 3 Curve Fitted Through Peak Value of Vibration Cycles Conductor at 25% RTS, 7 Vibration Loops, Hz 11

12 CTC ACCC/TW 15%RTS (Red represents 795 ACSR round wire conductor) Hz Hz Hz 12 Power Dissipation - mw/m Series Normalized Amplitude - Y/D Figure 4 Power Dissipation Characteristics of CTC 1020 kcmil ACCC/TW at 15% RTS (Logarithmic Decrement Method)

13 CTC ACCC/TW 20%RTS Hz Hz Hz 13 Power Dissipation - mw/m Normalized Amplitude - Y/D Hz Figure 5 Power Dissipation Characteristics of CTC 1020 kcmil ACCC/TW at 20% RTS (Logarithmic Decrement Method)

14 CTC ACCC/TW 25%RTS (Red represents 795kcmil ACSR round wire conductor) Hz 14 Power Dissipation - mw/m Normalized Amplitude - Y/D Hz Hz Hz Hz Hz Hz Hz Figure 6 Power Dissipation Characteristics of CTC 1020 kcmil ACCC/TW at 25% RTS (Logarithmic Decrement Method)

15 CTC ACCC/TW 30%RTS Hz Hz Hz Hz 15 Power Dissipation - mw/m Normalized Amplitude - Y/D Hz Hz Hz Hz Figure 7 Power Dissipation Characteristics of CTC 1020 kcmil ACCC/TW at 30% RTS (Logarithmic Decrement Method)

16 CTC ACCC/TW 40%RTS (Red represents 795 ACSR Round Wire) Hz Hz 16 Power Dissipation - mw/m Normalized Amplitude - Y/D Hz Hz Hz Hz Hz Hz Figure 8 Power Dissipation Characteristics of CTC 1020 kcmil ACCC/TW at 40% RTS (Logarithmic Decrement Method)

17 APPENDIX A DATA SHEET FOR CTC ACCC/TW 1020 KCMIL CONDUCTOR A-1

18 Cable Design for Trapezoidally Shaped Conductor Code Name: 1020 kcmil ACCC/TW Custom Design (24 wire) Type: 14 Governing Standard ASTM or CSA ASTM Total Cross Sectional Area of cndr in² ( mm²) AAC, ACSR, or ACSS ACSS Annular Alum area kcmil Aluminum Cross-Sectional Area kcmil ( mm²) Fill factor 93.8 % Calculated Cable OD in ( mm ) Design Area Alum kcmil Diameter of a strand wire in Core Strand in ( 9.53 mm ) Actual Alum. area kcmil No. Strand(s) in Core 1 No. Al. strands 24 No. of Alum. Wire Layers 2 No. Strands in 1st Layer 9 Al. in 1st layer % No. Strands in 2nd Layer 15 Al. in 2nd layer % No. Strands in 3rd Layer 0 Al. in 3rd layer 0.00 % No. Strands in 4th Layer 0 Al. in 4th layer 0.00 % Steel - GA, MA, HS, MS or S1A or S3A or AW CTC Core Conductivity of outer aluminum (%IACS) 63.0 % ASTM B857 for overall conductor Conductivity of inner core (%IACS).0 % ASTM B609 for 1350 O temper aluminum Frequency of Operation 60 Hz CTC Composite Fiberglass/ Carbon Fiber Core Conductor Design: Diameter of Steel Core.3750 in ( 9.53 mm ) 1st Layer - number of wires = 9 Equiv. Round Wire Dia in ( 5.25 mm ) Area per strand kcmil Diameter Over Layer.7416 in ( mm ) Height "t" in 2nd Layer - number of wires = 15 Equiv. Round Wire Dia in ( 5.23 mm ) Area per strand kcmil Diameter Over Layer in ( mm ) Height "t" in 3rd Layer - number of wires = 0 Equiv. Round Wire Dia in (.00 mm ) Area per strand. kcmil Diameter Over Layer.0000 in (.00 mm ) Height "t" in 4th Layer - number of wires = 0 Equiv. Round Wire Dia in (.00 mm ) Area per strand. kcmil Diameter Over Layer.0000 in (.00 mm ) Height "t" in Mechanical Properties: Aluminum (1350) CTC Core Total Conductor Mass 957 lb/kft 1425 kg/km 86 lb/kft 128 kg/km 1043 lb/kft 1553 kg/km Conductor Area.8012 sq.in sq.mm.1104 sq.in sq.mm.9116 sq.in sq.mm Rated Strength 6540 lb 29.1 kn lb kn lb * kn Tensile Strength Basis 8500 psi psi * value rounded to nearest 100lb unit Strength Derating Factor Thermal Heat Capacity W.s/ft per F per C tbd Electrical 60 Hz Temperature dc Resistance ac Resistance ac Resistance ac Resistance 20 C ohm/kft ohm/kft ohm/mile ohm/km ( ohm/km) 25 C ohm/kft ohm/kft ohm/mile ohm/km 50 C ohm/kft ohm/kft ohm/mile ohm/km 75 C ohm/kft ohm/kft ohm/mile ohm/km 100 C ohm/kft ohm/kft ohm/mile ohm/km 125 C ohm/kft ohm/kft ohm/mile ohm/km 150 C ohm/kft ohm/kft ohm/mile ohm/km 175 C ohm/kft ohm/kft ohm/mile ohm/km 200 C ohm/kft ohm/kft ohm/mile ohm/km A-2

19 ISO-9001 Form: QF11-1 Rev 0, APPENDIX B - INSTRUMENT SHEET Test Description: Self-Damping Test Test Start Date: April 20, 2004 Project Number: K Test Finish Date: April 23, 2004 TEST DESCRIPTION EQUIPMENT DESCRIPTION MAKE MODEL ASSET # or SERIAL # ACCURACY CLAIMED CALIBRATION DATE CALIBRATION DUE DATE TEST USE B-1 Self-Damping Load cell Aries TRC % February 11, 2004 February 11, 2005 Cable Tension Data acquisition National Instruments PCI-603E CCC % September 14, 2003 September 14, 2004 Data recording Accelerometer B&K % August 24, 2003 August 24, 2004 Displacement