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The use of multi-terminal high voltage direct current (HVDC) power transmission systems is being adopted in many new links between different generation and consumption areas due to their high efficiency. In these systems, cable energization must be performed at the rated voltage. Healthy energizations at the rated voltage result in large inrush currents, especially in long cables, primarily due to ground capacitance. State-of-the-art protection functions struggle to distinguish between transients caused by switching and those associated with ground faults, leading to potential unwanted tripping of the protection systems. To prevent this, tripping is usually blocked during the energization transient, which delays fault detection and clearing. This paper presents a novel method for prompt discrimination between healthy and faulty energizations. The proposed method outperforms conventional protection functions as this discrimination allows for earlier and more reliable tripping, thus avoiding extensive damage to the cable and the converter due to trip blocking. The method is based on the transient analysis of the current in the cable shields, therefore, another technical advantage is that high voltage-insulated measuring devices are not required. Two distinct tripping criteria are proposed: one attending to the change in current polarity, and the other to the change in current derivative sign. Extensive computer simulations and laboratory tests confirmed the correct operation in both cases. [ABSTRACT FROM AUTHOR]

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The selection of a grounding configuration and design of a grounding impedance is of vital importance for the stability and functionality of power systems, including industrial and commercial power systems. These key aspects of grounding systems have been the subject of various standards, industrial codes, and recommended practices. In this article, a review, modeling, and analysis of different grounding system designs are provided. The different grounding system design discussed in this article is compared in terms of the ground potential, ground currents, and overvoltage during ground faults. The various grounding system designs are implemented for power systems components in order to assess their capabilities and performance. Several tests are conducted for ground faults, when different grounding system designs are used. Test results show that some grounding system design can limit ground currents, with minor effects on ground potentials. Other grounding system design can limit ground potentials, while fail to limit ground currents. [ABSTRACT FROM AUTHOR]

Development of new deposits and modernization of existing mining enterprises in order to improve their efficiency are the priorities for the development of tungsten-molybdenum resource sector. In the modernization of mining productions, attention is paid to all technological processes and engineering systems, transformation of which should be aimed at improving economic performance, including reliability. Research of power supply systems of mining enterprises and modes of their operation is an urgent task, as this type of engineering support of mining works, auxiliary processes and facilities determines competitiveness of an enterprise as a whole. In the course of research, an assessment of operational reliability of power supply of developing ore mining areas at a high-altitude mine of the Tyrnyauz deposit (Kabardino-Balkaria) was performed. It was found that under the existing scheme of separate power supply of 6 kV networks from substations, the full ground fault currents for these networks are respectively: I030=17.5 A and I0116 =12.2 A and reach the limiting values at which it was possible to disconnect them by disconnectors (the limiting current was 20 A). A formula for total ground fault current in 6 kV underground networks was recommended. It was shown that reliability of power supply in the above mine, as well as the level of danger of electric shock in electrical installations depended largely on the number of singlephase ground faults. On the basis of the theoretical and experimental research, the solutions to improve the operation of electrical networks, taking into account the structure and modes of operation of a highaltitude mine were developed.

The prolonged undetected electrical faults in large-scale solar photovoltaic (PV) arrays are the main cause of fire hazards. In this paper, an effective method is proposed for detecting and locating faults in such large-scale PV arrays using cumulative sum of the changes in the string currents. The efficacy of the approach is evaluated on different electrical faults simulated on a 3 MW grid-connected solar PV plant through MATLAB/Simulink under varying system operating conditions. The findings clearly show that using this technique even critical faults such as high resistance ground faults, low mismatch faults and simultaneous faults in PV arrays can be detected and located within 5 ms. The comparative assessment results also justify the superiority of the proposed method over the available schemes. • The fault detection and localization challenges in large–scale solar PV array are addressed. • The cumulative sum (CUSUM) of the change in the string current is employed for detecting and locating faults in PV array. • The CUSUM–based method is computationally efficient as it requires only few additions and subtractions. • The efficacy of the method is validated on numerous fault and non–fault data simulated on a 3 MW grid–connected solar PV system through MATLAB/Simulink. [ABSTRACT FROM AUTHOR]

Electric faults in photovoltaic (PV) systems cause negative economic and safety impacts, reducing their performance and causing unwanted electric connections that can be dangerous for the user. Line to line, ground and open circuit faults, are three of the main faults that happen in a photovoltaic array system. This work proposes a characterization of the equivalent circuits and the voltage-power (VP) curves at the output of multiple PV arrays under different topological configurations and fault conditions to evaluate the effects of these three main faults on the performance of a photovoltaic array system, taking into account the temperature and solar radiation influence. This work presents a validation of the characterization by measuring the output VP curves of a low-power photovoltaic array system under real outdoors conditions. This method can be useful in future works to develop low cost systems capable of detecting and classifying electric faults in photovoltaic array systems.

Large fault currents in a synchronous-based distributed generators (SBDG) can cause serious damage to the core and windings of the generator. This article proposes an adaptive grounding scheme to limit the ground-fault currents to a safe level. To do so, a high-impedance grounding configuration is designed to operate during the grid-connected mode to minimize damage to the generator during ground faults. An electronic switching mechanism is provided to identify the islanded mode of operation. This switching operation strategy will modify the grounding system to the low-impedance configuration during the islanded-mode of operation of the SBDG to ensure the steadfast operation of the overcurrent protection (OCP) relays to prevent the nuisance tripping by the protective devices. Furthermore, the schematic diagram of the proposed grounding configuration has been presented and discussed to ensure the safe decay of the generator field current during ground faults in the generator zone while the generator has been isolated from the grid. Simulation results for different test systems, including the IEEE 34-bus test system, validate the effectiveness of the proposed adaptive grounding scheme to ensure the steadfast operation of the inverse OCP and to limit the fault energy dissipation level inside the SBDG to a safe level by maintaining an appropriate grounding scheme during different operating modes. [ABSTRACT FROM AUTHOR]

This study presents a robust Kalman filter‐based multifunctional control strategy, to enable wide‐scale utilisation of the grid‐interfaced solar energy conversion system (SECS). The presented control technique offers multifunctional features such as unity power factor, harmonics mitigation, reactive power compensation along with ride through operation under balanced and unbalanced low‐voltage faults in the distribution grid. Under fault in the grid side area, the DC–DC converter is controlled in a way that it reduces the active power injection and restricts the inverter currents within its maximum current limit. Based on the depth of grid voltage sag, reactive power supply to the grid is adaptively adjusted, as recommended by IEEE 1547‐2018 standard. To minimise the inverter losses, adaptive DC link voltage is introduced, which adapts the DC link voltage in proportion to the grid voltages. Simulation results exhibit the efficacious of the presented robust control strategy in achieving multifunctional features such as harmonics mitigation, grid currents balancing feature and reactive power requirement, under unbalanced line to ground (L‐G) and double line to ground faults. Test results demonstrate the satisfactory performance for diverse operating scenarios such as imbalanced currents in the load side network, SECS to DSTATCOM mode and vice‐versa, and L‐G fault. [ABSTRACT FROM AUTHOR]

As more than 80% of single line to ground faults in power transmission lines (PTLs) are transient, single pole auto‐reclosure (SPAR) is of considerable importance for increasing the successful SPAR rate, improving power system stability and reducing shocks to the power systems. In this study, a new two‐step strategy for ASPAR is presented. In the first step, the fault type (permanent or transient) is determined using the derivative of the first harmonic of the faulty phase voltage. Then in the second step, the extinguishing moment of the secondary arc is detected in the case of transient occurrence, in which the reclosing signal is sent to the side circuit breakers of the PTL after the secondary arc is completely extinguished. The major features of the proposed scheme are: its capability to detect the permanent fault from the transient one, and determine the extinguishing moment of the secondary arc without the need to define a specific threshold level, its independence from the PTL type and its appropriate structure that facilitates its online hardware implementation and makes it more comprehensive. Extensive simulations in the ElectroMagnetic Transient Program‐RV, as well as practical data testing, demonstrate the accuracy and precision of the proposed method. [ABSTRACT FROM AUTHOR]

A comprehensive knowledge of the available grounding strategies and their effects is essential for design, operation, and protection of the dc microgrid. This paper investigates and compares different dc microgrid grounding strategies that involve the choice of grounding configurations and grounding devices. The impacts of different grounding strategies on line-to-ground (LG) fault detection and protection, transient LG fault current magnitude, leakage current level, common mode voltage, personnel/equipment safety, system reliability, service continuity, and insulation requirements are thoroughly investigated. LG fault response of a low-voltage dc microgrid with different grounding devices is studied by detailed simulation of a realistic study system modeled in the PSCAD software. The study results indicate that: 1) the ungrounded, bipolar solidly grounded, unipolar parallel resistance grounded, and bipolar resistance grounded dc microgrids enable LG fault ride through, due to the low fault current; 2) the unipolar solidly grounded, bipolar solidly grounded, diode-grounded, and thyristor-grounded dc microgrids experience significantly large transient discharge currents under LG faults; and 3) the unipolar solidly grounded, diode-grounded, thyristor-grounded, and unipolar low-resistance-grounded dc microgrids provide considerable steady-state LG fault current which necessitates fast detection and clearance of faults. [ABSTRACT FROM AUTHOR]

High impedance grounding systems offer great service continuity by limitation of fault currents during single line to ground faults. Recently, a new power electronic based grounding system has been presented, in which an adjustable current was injected into the neutral point. This active grounding system operates as a high impedance grounding system to reduce fault currents, as well as induced over‐voltages. Identification of faulted feeder in a substation with some outgoing feeders from point of common coupling is a general issue in high impedance grounded networks. As a solution to this problem, this study proposes a new approach, to utilise the current injection capability of active grounding systems for detecting the faulted feeder while limiting the fault currents to an acceptable range. The proposed approach does not require any additional devices for faulted feeder detection. Moreover, it is able to identify the ground faults on the main bus. The proposed method is tested on two systems with different capacitive charging currents. Simulation results approve the high efficiency of the proposed method in faulted feeder identification. [ABSTRACT FROM AUTHOR]

Although the probability of occurrence of station internal ac grounding faults in modular multilevel converter (MMC)-based high-voltage direct-current systems is low, they may lead to severe consequences that should be considered when designing protection systems. This paper analyzes the characteristics of valve-side single-phase-to-ground (SPG) faults in three configurations of MMC systems. Fault responses for symmetrical monopole MMCs are first studied. Upper arm overvoltages and ac-side nonzero-crossing currents arising from SPG faults in asymmetrical and bipolar configurations are then investigated. DC grounding using an LR parallel circuit is employed to create current zero-crossings, which will enable the operation of grid-side ac circuit breakers. The theoretical analysis is verified through simulations performed in PSCAD/EMTDC, with simulation results and the theoretical analysis showing a good agreement. The studies in this paper will be valuable for the design of protection systems for station internal ac grounding faults. [ABSTRACT FROM AUTHOR]

Grounding strategy of an ac microgrid affects its line-to-ground fault response, personnel/equipment safety, service continuity, insulation requirements, and protection criteria. Therefore, a comprehensive knowledge of the available grounding strategies and their effects is essential for design and operation of the microgrid components and especially its protection. In this paper, characteristics of different ac distribution system grounding devices and grounding configurations are investigated. Subsequently, ac microgrid grounding requirements and issues are identified based on the unique characteristics and constraints of microgrids. The results of the aforementioned investigations are used to identify the best grounding strategies, i.e., grounding configurations, transformer connection types, and grounding devices, for the ac microgrid. The study results indicate that the four-wire multigrounded configuration is the most suitable choice for the majority of microgrids, especially in North America. The Yg/Δ and Yg/Yg transformers are identified as the most appropriate choices for distributed energy resources (DER) interface to the four-wire multigrounded microgrid. Besides, low-reactance and low-resistance grounding devices are recommended for the DER interface transformers. [ABSTRACT FROM AUTHOR]

The location of ground faults in railway electric lines in 2 × 5 kV railway power supply systems is a difficult task. In both 1 × 25 kV and transmission power systems it is common practice to use distance protection relays to clear ground faults and localize their positions. However, in the particular case of this 2 × 25 kV system, due to the widespread use of autotransformers, the relation between the distance and the impedance seen by the distance protection relays is not linear and therefore the location is not accurate enough. This paper presents a simple and economical method to identify the subsection between autotransformers and the conductor (catenary or feeder) where the ground fault is happening. This method is based on the comparison of the angle between the current and the voltage of the positive terminal in each autotransformer. Consequently, after the identification of the subsection and the conductor with the ground defect, only the subsection where the ground fault is present will be quickly removed from service, with the minimum effect on rail traffic. This method has been validated through computer simulations and laboratory tests with positive results.

Ground faults in electrical power systems represent more than 90% of total faults. Their detection, location, and elimination are essential and must be carried out in a precise way to allow multiterminal high-voltage direct current (HVDC) cable networks to operate in stable conditions by removing only the faulty cable from service. This paper presents a new differential protection method based on the measurement of currents at both ends of the shields of power cables. This new method is cheaper and easier to set in operation compared to other protection methods that measure currents circulating in the active conductors. The values of such intensities and their polarities were evaluated to know which cable had a ground fault in a multiterminal HVDC cable network. The method was successfully validated by computer simulations, and experimental results were successfully obtained.

Industrial power systems, whether low-voltage or medium-voltage systems, are the backbone of any industrial facility. To keep production going and minimize downtimes, they are required to be very reliable. Therefore, it is important to deploy various protection systems to detect and react appropriately to any abnormal condition that can lead to a failure to deliver power or to a hazardous condition. Ground faults are the most common condition experienced by a power system. Hence, the ability to detect and react as needed quickly is paramount. The goal of this paper is to help protection engineers, engineering consultants, and power system operators to apply ground-fault protection systems correctly while also complying with local electrical codes. [ABSTRACT FROM PUBLISHER]

Owing to the installation of autotransformers at regular intervals along the line, distance protection relays cannot be used with the aim of locating ground faults in 2 × 25 kV railway power supply systems. The reason is that the ratio between impedance and distance to the fault point is not linear in these electrification systems, unlike in 1 × 25 kV power systems. Therefore, the location of ground faults represents a complicated task in 2 × 25 kV railway power supply systems. Various methods have been used to localize the ground fault position in 2 × 25 kV systems. The method described here allows the location of a ground fault to be economically found in an accurate way in real time, using the modules of the circulating currents in different autotransformers when the ground fault occurs. This method first needs to know the subsection and the conductor (catenary or feeder) with the defect, then localizes the ground fault's position. [ABSTRACT FROM AUTHOR]

• A new mathematical formulation is derived for partially coupled transmission lines. • Applicability of the equations for both the partially coupled and parallel lines. • Accuracy improvement is achieved for the untransposed lines. • Accurate fault location when one line is in service and the other line is grounded. • An immune method against arcing faults, compact tower and some other conditions. The technical requirements and environmental limitations increase utilizing both the parallel and partially coupled transmission lines. However, it is very demanding to find the fault point of the single phase to ground faults owing to the mutual coupling which does exist between the two circuits in these transmission lines. Furthermore, in practice, most of the transmission lines are not transposed, which makes the fault location problem more challenging. In this paper, by presenting the simulation results of the fault location for a parallel line, it is revealed that for the untransposed lines, the two-ended fault location approach based on the zero sequence network has a better performance as compared to the negative sequence network based methods addressed in the technical literature. In this regard, this study deals with proposing a new ground fault location methodology for partially coupled transmission lines. Therefore, the fault location equations based on the zero sequence network are derived and presented for both operation modes, including 1) both lines are in service, and 2) one line is in service, and another one is disconnected and grounded at both sides. The proposed method can also be applicable for the parallel lines if the parameter associated with the mutual coupling is altered. This fault location approach employs the measured voltage and current phasors at both sides of the line. Furthermore, in order to assess the accuracy of the presented method, extensive simulation studies of untransposed partially coupled transmission lines are carried out in the PSCAD/EMTDC software. To this aim, the proposed method performance against different fault resistances, source impedances, measurement errors, arcing faults, compact towers, line length, and two-phase to ground faults is investigated. The simulation results demonstrate that the proposed method provides very good accuracy for fault location. [ABSTRACT FROM AUTHOR]

The 2 × 25 kV power supply system is the most frequently used traction rail system to provide the huge power needed by high-speed trains. However, locating the ground fault in this power supply system is more complicated than in other configurations of electrical railway power supply due to the installation of autotransformers throughout the line section. In previous papers, the authors have described a ground fault location method with an insignificant installation cost. The method and, moreover, the location discriminate between whether the ground fault is located between a positive conductor and ground or a negative conductor and ground. The current of the high-speed train influences the accuracy of the location of the ground fault. An additional factor which influences the location method is the existence of an arc resistance between the positive or negative conductor and ground. In this paper, the influence of high-speed train currents and arc resistances are analysed to evaluate the error in the location method. The major conclusion of the paper is that the location method has an acceptable precision even taking into consideration the high-speed train current and arc resistance. The validation of the method has been performed by laboratory tests and computer simulations with satisfactory results.

This paper presents a novel auto-reclosing blocking method for combined overhead-cable lines in power distribution networks that are solidly or impedance grounded, with distribution transformers in a delta connection in their high-voltage sides. The main contribution of this new technique is that it can detect whether a ground fault has been produced at the overhead line side or at the cable line side, thus improving the performance of the auto-reclosing functionality. This localization technique is based on the measurements and analysis of the argument differences between the load currents in the active conductors of the cable and the currents in the shields at the cable end where the transformers in delta connection are installed, including a wavelet analysis. This technique has been verified through computer simulations and experimental laboratory tests. [ABSTRACT FROM AUTHOR]

Owing to the installation of autotransformers at regular intervals along the line, distance protection relays cannot be used with the aim of locating ground faults in 2 × 25 kV railway power supply systems. The reason is that the ratio between impedance and distance to the fault point is not linear in these electrification systems, unlike in 1 × 25 kV power systems. Therefore, the location of ground faults represents a complicated task in 2 × 25 kV railway power supply systems. Various methods have been used to localize the ground fault position in 2 × 25 kV systems. The method described here allows the location of a ground fault to be economically found in an accurate way in real time, using the modules of the circulating currents in different autotransformers when the ground fault occurs. This method first needs to know the subsection and the conductor (catenary or feeder) with the defect, then localizes the ground fault’s position.

The location of ground faults in railway electric lines in 2 × 5 kV railway power supply systems is a difficult task. In both 1 × 25 kV and transmission power systems it is common practice to use distance protection relays to clear ground faults and localize their positions. However, in the particular case of this 2 × 25 kV system, due to the widespread use of autotransformers, the relation between the distance and the impedance seen by the distance protection relays is not linear and therefore the location is not accurate enough. This paper presents a simple and economical method to identify the subsection between autotransformers and the conductor (catenary or feeder) where the ground fault is happening. This method is based on the comparison of the angle between the current and the voltage of the positive terminal in each autotransformer. Consequently, after the identification of the subsection and the conductor with the ground defect, only the subsection where the ground fault is present will be quickly removed from service, with the minimum effect on rail traffic. This method has been validated through computer simulations and laboratory tests with positive results. [ABSTRACT FROM AUTHOR]

This paper presents a novel auto-reclosing blocking method for combined overhead-cable lines in power distribution networks that are solidly or impedance grounded, with distribution transformers in a delta connection in their high-voltage sides. The main contribution of this new technique is that it can detect whether a ground fault has been produced at the overhead line side or at the cable line side, thus improving the performance of the auto-reclosing functionality. This localization technique is based on the measurements and analysis of the argument differences between the load currents in the active conductors of the cable and the currents in the shields at the cable end where the transformers in delta connection are installed, including a wavelet analysis. This technique has been verified through computer simulations and experimental laboratory tests.

The power utility companies have been trying to identify and locate three‐phase transmission line faults in the shortest possible time in order to prevent economic losses. In the last few decades, technology used for power system protection has evolved from electromechanical devices to solid state and processor‐based intelligent devices. This study presents the design and implementation of a wavelet analysis‐based fault detection and identification module that contemplates the analysis of high frequency transients produced during faults. The design was implemented on a cost effective low‐end embedded system. The proposed logic employs a multi‐resolution wavelet analysis of high frequency details in the range of 5–10 kHz. The amount of high frequency components present in the transformed current signals, obtained after processing, identifies the fault. The ground and line‐to‐line faults were classified on the basis of the adaptive thresholds obtained from system behaviour. The proposed approach, after the completion of simulations, was implemented on a digital signal controller. The developed fault detection and identification prototype was successful in accurately identifying the power system faults, thus validating the feasibility of the proposed methodology. [ABSTRACT FROM AUTHOR]

Highlights: [•] A practical 20kV underground power distribution system is simulated. [•] A new method is proposed to analyze UDS transient signals by using WT technique. [•] This method is indeed to classify the fault type, fault branch and fault distance. [•] This approach based on combined WT and ANN–FLS is robust to different case studies. [•] This method gives a high accuracy in fault location under a whole of conditions. [Copyright &y& Elsevier]

Icing of overhead ground wires on transmission lines may result in faults and widespread power outages. This paper investigates the feasibility of an unconventional overhead line structure that is equipped with underground rather than overhead ground wires to prevent faults caused by icing. The underground ground wire is a buried bare conductor connected to the grounding of each transmission-line tower. To analyze the ground fault of the overhead line structure, this paper derives analytical equations to evaluate the current and potential distribution in the underground ground wire, earth surface potential around the wire, and grounding impedance of the faulted tower. The validity of the presented equations is verified by measurements. Based on the ground fault analysis, this paper evaluates the electrical safety of the discussed overhead line structure. Lightning shielding of overhead lines is not considered in this paper. [ABSTRACT FROM AUTHOR]

At the occurrence of phase-to-ground faults, abnormal levels of thermal energy I^2t, due to the Joule effect, will be developed during the clearing time that protective devices take to operate. The I^2t, also referred to as specific energy or Joule Integral, is accumulated within the elements forming the fault loop, such as the protective conductors (also referred to as equipment grounding conductors), responsible to return ground-fault currents to the source. As a consequence, the temperature of these conductors elevates and may exceed, in the case of an incorrect design, the maximum value that their insulation can withstand. This dangerous situation can cause the failure of the conductor insulation and/or trigger fires in neighboring materials. The maximum I^2t that protective conductors can endure is, therefore, crucial in order to guarantee the electrical safety. The parameters on which the maximum I^2t depends are described by the factor k^2, which will be herein discussed and analytically evaluated. The intention of the authors is to provide a theoretical support to the Power Systems Grounding Working Group of the Technical Books Coordinating Committee IEEE P3003.2 “Recommended Practice for Equipment Grounding and Bonding in Industrial and Commercial Power Systems”; the working group is currently elaborating a dot standard based on IEEE Standard 142-2007, also referred to as the Green Book. To this purpose, a comparison with existing formulas, currently present in codes, standards of the International Electrotechnical Commission and of the IEEE, as well in the literature, will be also presented. [ABSTRACT FROM PUBLISHER]

A survey was undertaken on the current assessment and refurbishment practices of North American utilities regarding substation grounding systems. The information was gathered using standard survey techniques where all interested parties were requested to fill out a short written survey and return it with the understanding that their responses would be kept anonymous. Survey results show that almost all utilities evaluate the integrity of their ground grids at some point, and have maintenance or engineering standards for determining the integrity. Test equipment is frequently used to evaluate integrity, and ground grids not meeting these standards are commonly upgraded. The results also show that most use high resistivity surfacing material, yet very few test the resistivity of the material at the lime it is installed. This paper provides guidance on the recommended best practices based on these survey results, which can be used for benchmarking purposes. It also includes a short discussion on the importance of maintaining the substation grounding system. [ABSTRACT FROM AUTHOR]

The share of photovoltaic (PV) power generation in the energy mix is increasing at a rapid pace with dramatically increasing capacity addition through utility-scale PV power plants globally. As PV plants are forecasted to be a major energy generator in the future, their reliable operation remains of primary concern due to a possibility of faults in a tremendously huge number of PV panels involved in power generation in larger plants. The precise detection of nature and the location of the faults along with a prompt remedial mechanism is deemed crucial for smoother power plant operation. The existing fault diagnostic methodologies based on thermal imaging of the panels as well as electrical parameters through inverter possess certain limitations. The current article deals with a novel fault diagnostic technique based on PV panel electrical parameters and junction temperatures that can precisely locate and categorize the faults. The proposed scheme has been tested on a 1.6 kW photovoltaic system for short circuit, open circuit, grounding, and partial shading faults. The proposed method showed improved accuracy compared to thermal imaging on panel scale fault detection, offering a possibility to adapt to the PV plant scale. [ABSTRACT FROM AUTHOR]

Ground faults in electrical power systems represent more than 90% of total faults. Their detection, location, and elimination are essential and must be carried out in a precise way to allow multiterminal high-voltage direct current (HVDC) cable networks to operate in stable conditions by removing only the faulty cable from service. This paper presents a new differential protection method based on the measurement of currents at both ends of the shields of power cables. This new method is cheaper and easier to set in operation compared to other protection methods that measure currents circulating in the active conductors. The values of such intensities and their polarities were evaluated to know which cable had a ground fault in a multiterminal HVDC cable network. The method was successfully validated by computer simulations, and experimental results were successfully obtained. [ABSTRACT FROM AUTHOR]