Method for predicting arc flash energy and PPE category within a real-time monitoring system

• US 8,868,398 B2
• Filed: 10/10/2008
• Issued: 10/21/2014
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Power Analytics Corporation (PAC Global, Inc.)
• Original Assignee: Power Analytics Corporation (PAC Global, Inc.)
• Inventors: Radibratovic, Branislav, Nasle, Ali
• Primary Examiner(s): Rivas, Omar Fernandez
• Assistant Examiner(s): CALLE, ANGEL J.
• Application Number:
  US12/249,698
• Publication Number:
  US 20090105998A1
• Time in Patent Office: 2,202 Days
• Field of Search: 703/18, 703/5, 703/9, 703/14, 700/286, 700/291, 361/42
• US Class Current: 703/18
• CPC Class Codes: G05B 13/048 using a predictor
• CPC Class Codes: G05B 17/02 electric
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 17/10 Complex mathematical operations function generation by table look-up G06F1/03; evaluation of elementary functions by calculation G06F7/544
• CPC Class Codes: G06F 2111/02 CAD in a network environment, e.g. collaborative CAD or distributed simulation
• CPC Class Codes: G06F 2111/10 Numerical modelling
• CPC Class Codes: G06F 30/20 Design optimisation, verification or simulation optimisation, verification or simulation of circuit designs G06F30/30
• CPC Class Codes: G06F 30/367 Design verification, e.g. using simulation, simulation program with integrated circuit emphasis [SPICE], direct methods or relaxation methods
• CPC Class Codes: G06G 7/63 for power apparatus, e.g. motors, or supply distribution networks for control systems of electric power apparatus G06G7/66
• CPC Class Codes: G06N 7/00 Computing arrangements based on specific mathematical models
• CPC Class Codes: H02H 1/0015 Using arc detectors
• CPC Class Codes: H02J 2203/20 Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation

Abstract

A method for simulating an arc flash event on an electrical power system is disclosed. The virtual system model of the electrical system is modified to introduce a short circuiting feature. The standard to supply equations used in the arc flash event calculations is chosen. The arc flash event is simulated using the modified virtual system model in accordance with the chosen standard. The quantity of arc energy released by the arc flash event is calculated using results from the simulation. The report that forecasts an aspect of the arc flash event is communicated.

Claims

1. A computer-implemented method for simulating an arc flash event on an electrical power system, the method comprising:

synchronizing a virtual system model of the electrical power system with a real-time model of the electrical power system in real-time based on real-time data from the electrical power system when a difference between the real-time data and predicted data generated using the virtual system model exceeds a threshold;

modifying the virtual system model of the electrical power system to introduce a short circuiting feature to an uninterrupted power supply bypass circuit branch;

choosing a standard to supply equations used in the arc flash event calculations;

simulating the arc flash event utilizing the modified virtual system model;

calculating a quantity of arc energy released by the arc flash event using results from the simulation; and

communicating a report that forecasts an aspect of the arc flash event.

2. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the arc flash event is an alternating current arc flash event.

3. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the standard applied is IEEE 1584.

4. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 3, wherein the calculation of the quantity of arc energy released includes:

determining bolted fault current values for the electrical system;

determining a system voltage level for the electrical system;

identifying an equipment classification for a protective device impacted by the arc flash event;

calculating a first arcing current value and a second arcing current value, wherein the second arcing current value is 15 percent (%) less than the first arcing current value;

performing a time-current curve analysis for the first arcing current value and the second arcing current value to respectively determine a first fault clearing time and a second fault clearing time for the protective device;

calculating a first arcing energy quantity using the first arc current value and the first fault clearing time;

calculating a second arcing energy quantity using the second arc current value and the second fault clearing time; and

selecting a larger of the first arcing energy quantity and the second arcing energy quantity as the quantity of arc energy released by the protective device.

5. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the standard applied is NFPA 70E.

6. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 5, wherein the calculation of the quantity of arc energy released includes:

determining bolted fault current values for the electrical system;

determining a system voltage level for the electrical system;

identifying an equipment classification for a protective device impacted by the arc flash event; and

predicting the required PPE level as per Table 130.7(C)(9)(a) of NFPA 70E.

7. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the forecasted aspect is an arc flash protection boundary around a component within the electrical system.

8. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 7, wherein the component is a protective device.

9. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 8, wherein the protective device is a circuit breaker.

10. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 8, wherein the protective device is a fuse.

11. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 8, wherein the protective device is a relay.

12. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the forecasted aspect is a level of personal protective equipment (PPE) to be worn by personnel operating around components of the electrical system.

13. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 12, wherein the level of PPE is based on National Fire Protection Association (NFPA) 70E classification categories.

14. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 13, wherein the NFPA 70E classification categories is selected from a group consisting of Category 0, Category 1, Category 2, Category 3, and Category 4.

15. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 14, wherein Category 0 denotes that the PPE must withstand minimum incident energy of 1.2 Cal/cm².

16. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 14, wherein Category 1 denotes that the PPE must withstand minimum incident energy of 4 Cal/ cm².

17. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 14, wherein Category 2 denotes that the PPE must withstand minimum incident energy of 8 Cal/ cm².

18. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 14, wherein Category 3 denotes that the PPE must withstand minimum incident energy of 25 Cal/cm².

19. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 14, wherein Category 4 denotes that the PPE must withstand minimum incident energy of 40 Cal/cm².

20. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the report is communicated using graphics rendered on a terminal display.

21. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the report is communicated using text rendered on a terminal display.

22. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, wherein the report is communicated by way of synthesized speech generated by a client terminal.

23. The computer-implemented method for simulating an arc flash event on an electrical power system, as recited in claim 1, further including:

creating arc flash labels displaying the forecasted aspect.