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Introduction

1

Introduction

The RD-195 reference design includes the SM73201-ARC-EV PCB which is a UL1699B compliant Photo-
Voltaic Arc Detect System with a minimal footprint of less than 50mm x 30mm. The reference design
utilizes a proprietary dynamic filtering technique to effectively detect the signature of arcing conductors in
the presence of highly noisy real world environments. The analog path requires less than 50mW of power
to implement the active filtering. The operation range of the device covers the industrial temperature range
of -40°C to +85°C.

2

Features

1,000V isolation

Effective detection at maximum DC string current of 15A

Simple LED arc detection flag

Self Test Capability

Industrial Temperature Range (-40°C to +85°C)

Small PCB footprint for active area of less than 50mm x 30mm, single sided

Low power requirement < 400mW, analog power < 50mW

Figure 1. Evaluation board

(1)

3

Connection

The multiple connections on the Evaluation Board are labeled. Refer to the table below for a description of
their usage.

3

SNOA564F – June 2011 – Revised December 2012

AN-2154 RD-195 DC Arc Detection Evaluation Board

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Copyright © 2011–2012, Texas Instruments Incorporated

Summary of Contents for AN-2154

Page 1: ...5 LED functionality 4 6 RS232 Interface Operation 4 7 RS232 Settings 4 8 RS232 Commands 5 9 Complete List of RS232 Commands 5 10 Raw Data Capture 6 11 Theory of Operation 6 12 System Implementation 7...

Page 2: ...ect View in CCS 17 21 Build Configurations 18 22 Flash Linker Command File 19 23 Board Assembly TOP 21 24 Board Assembly BOTTOM 22 List of Tables 1 SM73201 Arc Evaluation Module Directory Structure De...

Page 3: ...f the device covers the industrial temperature range of 40 C to 85 C 2 Features 1 000V isolation Effective detection at maximum DC string current of 15A Simple LED arc detection flag Self Test Capabil...

Page 4: ...Interface Operation The Evaluation Board can output its arc detection status via an RS232 interface located at connector J14 It will periodically issue a message stating No Arc Detected or Arc Detect...

Page 5: ...iltering is and F 4 00 which must be a number greater than 0 0 for proper operation Note corrects for the arc signature that the Arc Detection routine is re initialized after a set command shaping set...

Page 6: ...ons that are on the line e g inverter_A_10panels_no_arc txt when click Start You can then capture the data with get W 2000 Once the text transfer is complete after approximately 2 seconds close the Hy...

Page 7: ...ignals 93 dB greater than the noise that needs to be measured for arc detection purposes Figure 2 shows the spectrum 10kHz 130kHz in dB of the sensed current after filtering and sampling with arc and...

Page 8: ...mplifiers The output of U18B is the input to the A D conversion circuit The filter has a cutoff frequency of 40kHz for the low limit and 100kHz for the high limit This bandwidth is necessary for the p...

Page 9: ...R52 R54 R55 R64 VREF VREF VREF VREF VREF J2 J1 U14A U15A U18A U14B U15B U18B TP17 ADC_INPUT TP15 VREF SELF_TEST R99 www ti com Design Description Figure 6 Analog Front End Figure 7 Reference voltage 9...

Page 10: ...e potentially higher amplitude of interference signals from the inverter The converter sampling rate is controlled by the microcontroller The connection is shown in Figure 9 Figure 9 A D Converter 15...

Page 11: ...nt measurements in conjunction with an RD 195 provides a method to detect and differentiate both types of arcs The appropriate response to detection of an arc is system dependant While a series arc ca...

Page 12: ...e a controllable electrical arc See Figure 13 The Arc Generation unit is not a commonly available piece of lab equipment See Figure 14 They can be built using polycarbonate enclosure surrounding a kni...

Page 13: ...icture of the Arc Generation unit producing an arc This arc was generated with the DC power supply set to 130V with a maximum current of 2 0A 13 SNOA564F June 2011 Revised December 2012 AN 2154 RD 195...

Page 14: ...structure while the subsequent Table 1 provides a description for each folder Figure 17 Directory Structure of the SM73201 Arc Evaluation Module Table 1 SM73201 Arc Evaluation Module Directory Struct...

Page 15: ...y The path to this library must be included in your project i e INSTALLROOT_TO_FIXEDPOINT_VERSION include Finally if you plan on using the test vectors provided with the library to gauge the accuracy...

Page 16: ...w of the demo once it is imported into CCSv4 v5 is shown below in Figure 20 and the description of the constituent files is given in the Table 2 Table 3 and Table 4 16 AN 2154 RD 195 DC Arc Detection...

Page 17: ...etection spiADC h SPI A Macros and Function Prototypes Arc_Detection STKOV h Stack Overflow Protection Macros and Function Protoypes Table 3 Project Source File Description Folder Description Arc_Dete...

Page 18: ...35 The Flash Linker Command File specifies the memory blocks and code sections for this example as shown in Figure 22 The following Table 5describes the main code sections NOTE THE SECTIONS AND MEMORI...

Page 19: ...be written to FFTtf Section for the FFT Twiddle Factors FFTipcb Section for the complex FFT input buffer The default size is 4096 words 1024 inputs 2 complex 2 32 bits wide This buffer must be aligne...

Page 20: ...2589 7 2098 The user should note that the algorithm makes a determination of whether an arc has occurred or not over 10 iterations of the DoArcDetect routine therefore the time per iteration of the al...

Page 21: ...ut 23 Layout Figure 23 Board Assembly TOP 21 SNOA564F June 2011 Revised December 2012 AN 2154 RD 195 DC Arc Detection Evaluation Board Submit Documentation Feedback Copyright 2011 2012 Texas Instrumen...

Page 22: ...LibRef Quantity C1 C6 C7 C8 C13 C43 C47 C52 C56 C59 C60 C61 C68 C69 C71 C72 C77 C80 C88 CAP CER 10UF 16V X7R AUTO 0402 TDK CGA2B1X7R1C104K 18 22 AN 2154 RD 195 DC Arc Detection Evaluation Board SNOA5...

Page 23: ...5V 200MW SC70 3 Diodes BAV99W 7 F 1 J1 J2 TERM QF 032DIA 250 STURDY MT Keystone 1289 ST 2 Header TH 100mil 3x1 Gold plated 230 mil J3 J14 above insulator Samtec TSW 103 07 G S 2 J4 J6 J9 CONN HEADER 2...

Page 24: ...2 RES 1 00Meg ohm 1 0 063W 0402 Vishay Dale CRCW04021M00FKED 2 R99 RES 49 9 ohm 1 0 1W 0603 Vishay Dale CRCW060349R9FKEA 1 SW1 SWITCH TACTILE SPST NO 0 02A 15V Panasonic EVP AA202K 1 T3 XFRMR CURR SEN...

Page 25: ...ing the warranty period to the address designated by TI and that are determined by TI not to conform to such warranty If TI elects to repair or replace such EVM TI shall have a reasonable time to repa...

Page 26: ...transmitter has been approved by Industry Canada to operate with the antenna types listed in the user guide with the maximum permissible gain and required antenna impedance for each antenna type indic...

Page 27: ...ified allowable ranges some circuit components may have elevated case temperatures These components include but are not limited to linear regulators switching transistors pass transistors current sens...

Page 28: ...REMOVAL OR REINSTALLATION ANCILLARY COSTS TO THE PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES RETESTING OUTSIDE COMPUTER TIME LABOR COSTS LOSS OF GOODWILL LOSS OF PROFITS LOSS OF SAVINGS LOSS OF USE L...

Page 29: ...sponsible for compliance with all legal regulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related inf...

Page 30: ...Mouser Electronics Authorized Distributor Click to View Pricing Inventory Delivery Lifecycle Information Texas Instruments SM73201 ARC EV NOPB...

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