Challenges to overcurrent protection devices under line-line faults in solar photovoltaic arrays

Zhao, Yi; Lehman, Brad; Palma, Jean-François de; Mosesian, Jerry; Lyons, Robert

doi:10.1109/ecce.2011.6063744

Cited by 36 publications

(20 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…GFPD resistance vs. rating for a variety of 10x38 mm ("midget") fuses by various PV fuse manufacturers. In general, the more sensitive the fuse, the higher the intrinsic resistance [10][11][12][13][14][15][16][17].…”

Section: Fuse-based Gfpdmentioning

confidence: 99%

“…So, by inserting (5) into (4) and solving for I fault , the fault current can be described by: (6) The GFPD current is the difference in the fault and leakage currents (since they are opposite in direction), so I fault can be transformed into I GFPD by: (7) Finally, (6) can be solved in terms of I GFPD by substituting (7): (8) In simulations, the recombiner topology has not been used (D=1, R recomb =0 Ω), so the equation for I GFPD shown as (8) becomes: (9) The use of computer circuit simulation tools can describe the behavior of a PV system for a wide variety of fault conditions [10]. Since PV modules are non-linear circuits, their behavior is difficult to describe analytically without transcendental equations.…”

Section: Fuse-based Gfpdmentioning

confidence: 99%

See 1 more Smart Citation

Photovoltaic ground fault detection recommendations for array safety and operation

Flicker¹,

Johnson²

2016

Solar Energy

View full text Add to dashboard Cite

PV faults have caused rooftop fires in the United States, Europe, and elsewhere in the world. One prominent cause of past electrical fires was the ground fault detection "blind spot" in fuse-based protection systems discovered by the Solar America Board for Codes and Standards (Solar ABCs) steering committee in 2011. Unfortunately, while a number of alternatives to ground fault fuses have been identified, there has been limited adoption or historical use of these technologies in the U.S. Analytical and numerical SPICE simulations were conducted for a wide variety of ground faults and array configurations to understand the limitations of fuse-based ground fault protection in PV systems and determine proper trip settings for alternative GFPDs. Simulation results were compared with experimental measurements on arrays to validate the SPICE model as well as provide direction on proper thresholding of residual current detector (RCD), current sense monitor (CSM) and isolation monitor (R iso) devices based on historical fault current data. We argue the combination of simulation results with historical data indicates robust settings are possible for each of these technologies to minimize unwanted tripping events while maximizing PV fault detection.

show abstract

Section: Fuse-based Gfpdmentioning

confidence: 99%

Section: Fuse-based Gfpdmentioning

confidence: 99%

Photovoltaic ground fault detection recommendations for array safety and operation

Flicker¹,

Johnson²

2016

Solar Energy

View full text Add to dashboard Cite

show abstract

“…Their behavior is difficult to describe analytically without transcendental equations, but the use of computer circuit simulations can describe the behavior of a PV system for a wide variety of fault conditions [2]. A common method of circuit simulation is the use of the Simulation Program with Integrated Circuit Emphasis (SPICE).…”

Section: Spice Pv Model and Inverter Model Creationmentioning

confidence: 99%

Photovoltaic ground fault and blind spot electrical simulations.

Flicker¹,

Johnson²

2013

View full text Add to dashboard Cite

Ground faults in photovoltaic (PV) systems pose a fire and shock hazard. To mitigate these risks, AC-isolated, DC grounded PV systems in the United States use Ground Fault Protection Devices (GFPDs), e.g., fuses, to de-energize the PV system when there is a ground fault. Recently the effectiveness of these protection devices has come under question because multiple fires have started when ground faults went undetected. In order to understand the limitations of fuse-based ground fault protection in PV systems, analytical and numerical simulations of different ground faults were performed. The numerical simulations were conducted with Simulation Program with Integrated Circuit Emphasis (SPICE) using a circuit model of the PV system which included the modules, wiring, switchgear, grounded or ungrounded components, and the inverter. The derivation of the SPICE model and the results of parametric fault current studies are provided with varying array topologies, fuse sizes, and fault impedances. Closed-form analytical approximations for GFPD currents from faults to the grounded current carrying conductor-known as "blind spot" ground faults-are derived to provide greater understanding of the influence of array impedances on fault currents. The behavior of the array during various ground faults is studied for a range of ground fault fuse sizes to determine if reducing the size of the fuse improves ground fault detection sensitivity. The results of the simulations show that reducing the amperage rating of the protective fuse does increase fault current detection sensitivity without increasing the likelihood of nuisance trips to a degree. Unfortunately, this benefit reaches a limit as fuses become smaller and their internal resistance increases to the point of becoming a major element in the fault current circuit.4

show abstract

“…A simple investigative method to identify the number of open and short-circuited PV modules in a string with a small number of sensors is presented in [14]. Line to line fault that occurs under low irradiance conditions and occurring in PV arrays where blocking diode have been used is stated in [15]. A fault identification method based on the extended correlation function and the matter element model has been presented in [16].…”

Section: Introductionmentioning

confidence: 99%

Fault Identification and Islanding in DC Grid Connected PV System

Paul¹,

Mahalakshmi²,

Karuppasamypandiyan³

et al. 2016

View full text Add to dashboard Cite

Nowadays, the DC distribution system has been suggested, as a replacement for the AC power distribution system with electric propulsion. This idea signifies a fresh approach of issuing energy for low-voltage installations. It can be used for any electrical application up to 20 MW and works at a nominal voltage of 1000 V DC. The DC distribution system is just an extension of the multiple DC links that previously available in all propulsion and thruster drives, which typically comprise more than 80% of the electrical power consumption on electric propulsion vessels. A fault detection and islanding scheme for DC grid connected PV system is presented in this paper. Unlike traditional ac distribution systems, protection has been challenging for dc systems. The goals of this paper are to classify and detect the fault in the PV system as well as DC grid and to isolate the faulted section so that the system keeps operating without disabling the entire system. The results show the measured values of power at PV panel and DC grid side under different fault condition, which indicates the type of fault that occurs in the system.

show abstract

Challenges to overcurrent protection devices under line-line faults in solar photovoltaic arrays

Cited by 36 publications

References 9 publications

Photovoltaic ground fault detection recommendations for array safety and operation

Photovoltaic ground fault detection recommendations for array safety and operation

Photovoltaic ground fault and blind spot electrical simulations.

Fault Identification and Islanding in DC Grid Connected PV System

Contact Info

Product

Resources

About