Magnetohydrodynamic electromagnetic pulse (MHD-EMP) interaction with power transmission and distribution systems

This paper summarizes a method to evaluate the possible effects of magnetohydrodynamic-electromagnetic pulse (MHD-EMP) on power systems. This method is based on the approach adapted to study the impact of geomagnetic storms on power systems. The paper highlights the similarities and differences between the two phenomena. Also presented are areas of concern which are anticipated from MHD-EMP on the overall system operation.

The potentially imminent and existential threat from a nuclear electromagnetic pulse are arguably inflated, voiced to garner attention to the true issue, that today’s microelectronics are incredibly vulnerable to electromagnetic damage caused by sudden voltage spikes from the electromagnetic pollution. Additionally, a nuclear electromagnetic pulse does not need to be detonated in outer space to cause signification disruption to communications systems’ data and information flow across the celestial domain. High altitude electromagnetic pulse (HEMP) detonations do not need to occur in outer space to have wide ranging effects; in describing electromagnetic pulses, the high-altitude moniker is tied to any detonation above nineteen miles (thirty point-five kilometers). High altitude electromagnetic pulse detonations ranging from fifty to one hundred kilometers can project wave effects into outer space and affect spacecraft through both direct damage (contemporary views regarding electromagnetic pulse) and radiation-induced torques on the solar arrays, misaligning satellite antennas and sensors. If an actor – state or otherwise – wished to compete or contest another along the congested celestial lines of communications (CLOCs), it can be done at great distance from the affected entity by use of a high altitude electromagnetic pulse on the ‘far side’ of the orbit. Additionally, the historic maritime tactic of blockade has applicability in space; yesterday’s ships are today’s gamma ray damage to microelectronics. Furthermore, the employment of a nuclear weapon-delivered high-altitude electromagnetic pulse remains a treaty violation, for those who are a party to. However, greater jurisprudence study is lacking regarding this matter, and the accompanying concern of transboundary harm as it relates to territorial sovereignty. In summary, an actor can contest another’s use of the celestial lines of communications by detonating a nuclear weapon, at high-altitude but within the atmosphere (i.e., below one hundred kilometers), and within the lateral boundaries of their sovereign territory and associated territorial waters, and allow wave’s effects to radiate widely to interrupt operations and possibly inflict permanent damage, all without being in violation of treaty or customary law. This manuscript substantiates the prequel baseline for follow-on research on mitigation of the deleterious effects on communication system circuits in attempts to void the blockage on celestial lines of communications, and the sequel is briefly introduced with a short description of the state-of-the-art research.

The purpose of this report is to develop an engineering design package to protect the Federal Emergency Management Agency (FEMA) National Radio System (FNARS) facilities against the effects of high-altitude electromagnetic pulses (HEMPS). This report refers to the FEMA Federal Regional Center (FRC) in Bothell, Washington. It is highly probably that there will be a heavy dependence upon high-frequency (hf) radio communications for long-haul communications following a nuclear attack on the continental United States, should one occur. To maintain the viability of the FEMA hf radio network during such a situation, the FNARS facilities must take measures to protect against the effects of HEMP that are likely to be created in a nuclear confrontation. The equipment under stress has already been designed and built so that little opportunity exists for equipment design changes that could raise the threshold levels at which malfunctions occur. The solution must then be to reduce HEMP-induced stresses on the system by means of tailored retrofit hardening measures using commercial protection devices when available. If is the intent of this report to define the particular hardening measures that will minimize the susceptibility of the network components to HEMP effects. To the extent economically viable, protective actions have been recommended for implementation, along with necessary changes or additions, during the period of the FNARS upgrade program. This report addresses electromagnetic pulse (EMP) effects only, and disregards any condition in which radiation effects may be a factor. This report identifies the systems in the facility considered critical for emergency option. To identify the critical systems in the facility and the EMP coupling paths into these systems, an EMP survey of the facility was conducted. Results of the survey are presented along with recommendations for tailored retrofit hardening measures to be implemented to protect the facility from EMP.

A nuclear detonation in or above the earth's atmosphere produces an intense electromagnetic pulse (EMP). A large portion of the EMP electromagnetic energy is within the RF spectrum. A detonation at high altitudes above 40 km produces an EMP called high-altitude EMP (HEMP). HEMP is a steep-front short duration transient with a rise time on the order of a few nanoseconds which decays to near zero in less than a microsecond. A single high-altitude burst can subject much of the continental United States to intense HEMP electric fields on the order of tens of kilovolts per meter. The intense transient HEMP will induce fast transients in high-voltage transmission lines and bus structures, instrumentation cables, and control wires in power transmission and distribution (T D) substations. A system of traveling wave coupling models for a 500 kV substation, including models for the high voltage primary bus, components (circuit breakers, disconnect switches, power transformers, and current and voltage instrument transformers), low voltage control wiring circuits, and a number of conducted and radiated interference coupling modes, had been developed earlier by EPRI. These EPRI served as the baseline for the present HEMP coupling investigations. The HEMP effects on protective relays were assessed for a nominal HEMP environment using several new field coupling models merged with the switching transient data. It is found that a representative solid state relay is unlikely to be damaged or to misoperate by the nominal HEMP threat with a peak field strength of 50 kV/m. However, it is possible for both DC control wires to flash over to ground simultaneously, causing fuses to blow and placing the relay in an inoperative state.

The high-altitude burst of a nuclear device over the continental United States can expose civilian electric utility systems to transient electromagnetic pulses (EMP). The electromagnetic fields experienced within one second after the burst have been collectively defined by the term high-altitude EMP (HEMP). The phenomena has been subdivided, for this report, into an early-time HEMP field followed by an intermediate-time HEMP field. This volume documents a preliminary research effort to: investigate the nature and coupling of the HEMP environments to electric power systems, define the construction of approximate system response models, and document the development of a methodology to assess equipment and system vulnerability.

In the process of power supply to final consumers, an important amount of energy is lost in the transmission and distribution systems due to technological and non-technological losses. Technical losses represent an economic loss with environmental effects at national level, and its optimization should be performed from an overall national's perspective, regardless of the institutional organization of the sector and ownership of operating electricity utilities. The volume of energy losses in the power transmission and distribution systems is important, as it is generally up to 3 - 13%. The volume of power losses in Romanian power transmission and distribution systems is important, the level being of about double to the average in Europe. The current paper presents the research results of the authors regarding the real time monitoring and analysis systems for power losses, in electrical transmission and distribution systems.Within the research project, it was developed a dedicated system, successfully tested within a 5 years partnership with CNTEE “Transelectrica” - SA, on a transformer of 250/250/80MVA 400/121/20 kV from 400/110 kV Pelicanu Substation and respectively on the 400 kV overhead power line (118 km) Bucuresti Sud - Pelicanu.The tests results showed the importance of evaluation by real-time measurements, compared to the results of evaluations by calculations, of active power losses at power transformers and overhead power lines, respectively. Values several times higher were found for the values of active power losses measured online, in real time, than those determined by calculations.Online measurements have shown that there may be cases when large industrial consumers produce current and voltage harmonics well above the maximum allowable limits specified in the standards. The harmonics are transmitted practically undamped by the windings of the power transformers and on the transmission power lines (in the case of tests, even more than 100 km away from the place of their production).The online measurement of active power losses on the 400 kV overhead power line, 119 km, showed that corona losses are insignificant especially during periods of atmospheric humidity below 85%, and that active losses on power lines are practically resistive losses. The resistive losses on the measured high voltage overhead power lines are much higher than the calculated ones. The difference is determined by the fact that the calculation of active power losses on power lines includes the value of ohmic resistances of conductors evaluated based on line conductor resistivity or possibly based on ohmic resistance measured at a certain moment, and not the real value of the ohmic resistance of the line in real time (which changes over time due to the change in the state of the multitude of joints of the OHL conductor sections).

This paper gives an overview of the techniques and processes used to protect or ‘harden’ electronic equipment against the effects of the Nuclear Electromagnetic Pulse (EMP). Working from an engineering viewpoint, it not only considers how the threat operates and why it is a threat, but also it considers the measures that can be used to counter the threat andwhat these measures are attempting to achieve. Throughout it is stressed that once the decisionto harden a new piece of equipment is taken, the effects of EMP must be considered during all stages of its development. The paper is then concluded with a list of the typical activities that this might entail.

A High - Altitude Electromagnetic Pulse (HEMP) is a potential threat to the power grid . HEMP can couple to transmission lines and cables , causing significant overvoltages which c an be harmful to line connected equipment . T he e ffects of overvoltages on various types of power systems components need to be understood. HEMP effects on t rip c oil s w ere tested and presented in this report . A high voltage pulser was built to replicate the induced voltage waveform from a HEMP. T he pulser was used to test breake r trip coils with increasing pulse magnitude s ranging from 20 kV to 80 kV . T he State - of - Health of each trip coils was measured via mechanical operation and impedance measurements before and after each insult to identify any damage or degradation to the trip coils . Dielectric breakdown was observed at the conductor leads during testing , causing the HEMP insult to be diverted to the grounded casing. Ho wever , the dielectric breakdown did not caus e interfere ne w ith regular device operation .

This paper presents theoretical and experimental study of effective coupling length (ECL) for transmission lines illuminated by a high-altitude electromagnetic pulse (HEMP). Based on the transmission line theory, the ECL of transmission lines is analyzed theoretically and numerically first, then the ECL is applied to simply the analysis of nonuniform fields coupling with a power line, and some conclusions are validated experimentally. The impacts of the incident angles, the line height, and the ground conductivity on the ECL are given. The results show that the ECL for transmission lines illuminated by the HEMP defined by the IEC standard can range from tens of meters to hundreds of meters. The results also imply that the coupled current of a load is mainly determined by the field coupling with the line section, which adjoin the load and has the same length as the ECL. This conclusion is also validated by the experiment. This study can be useful to simply the solution of HEMP or nonuniform fields coupling with long lines or large-scale networks, which may be rather tricky when computing the problem directly.

The existence of electrical energy to human needs can not be separated, electrical energy is used by all humans on this planet from small scale region (household) to large-scale region such as industr ies . T he electric energy quantity and quality demand of the electric ity transmission system has been increas ing over the time . Failure in the electricity transmission system can be fatal to the electrical components or operati onal loss in an industry. SCADA is proposed t o accommodate th ese problems . It capable s to monitor and control the disturbance on the electrical redundant system. The purpose of this final project is to simulate the SCADA on redundant power system to eliminate the failure of power transmission lines such as open-circuit failure , short circuit, and overload that can be controlled directly from the plant or through a computer interface. The Finite State Machine (FSM) and ladder diagram programming language are used to design the PLC system . There are hardware and software to support this final project , such as plant of redundant electrical systems, PLC CPM1A Omron, Laptop , CX One 9.0 software for programming the PLC and the CX Supervisor 3.0 to build the HMI. T he result showed that the current sensors can be used to detect overload failure and simulate short circuit failure . Plant redundant electrical system can be monitored and controlled through the input-output of the plant, the interface on the computer, and W orld Wide Web . T here is a relay on plant that can connect power lines to cutting power lines when the failure occurs. If an failure occurs in the form of open circuit, short circuit or overload the alarm and failure indicator will active. Keyword : SCADA, PLC, open circuit, short circuit, overload

고 고도 전자기 펄스(HEMP: High-altitude Electromagnetic Pulse)용 필터는 펄스 전류 주입(PCI: Pulsed Current Injection) 인수시험을 통해 인수기준을 충족하더라도, 실제 부하 장비를 연결하여 장비 운용 상태에서 실시하는 PCI 검증 시험수행 시에는 부하 장비의 전자기 전도 내성 수준에 따라서 장비가 손상될 수도 있다. 본 논문에서는 HEMP 방호시설에서 PCI 검증 시험 수행이 어려운 경우, 이에 대한 방안으로서 HEMP 필터의 PCI 인수시험 잔류 전류 측정값과 부하 장비의 과도 전자기 전도 내성 기준 값에 대한 특성인자(norm) 비교를 통해 필터 잔류 전류가 부하 장비에 미치는 영향분석 방법을 제안하였다. C4I(Command, Control, Communications, Computer, and Intelligence) 쉘터용으로 제작된 HEMP 필터와 쉘터 탑재장비를 활용하여 HEMP 필터 PCI 인수시험, 과도 전자기 전도 내성 시험 및 PCI 검증 시험을 수행하였고, 결과를 분석하였다. Although High-altitude electromagnetic pulse(HEMP) protection filter meets the requirements of pulsed current injection(PCI) acceptance test, the equipment under test which has low electromagnetic susceptibility level can be damaged during PCI verification test that is performed on operating condition of equipment. This paper proposed the HEMP effect analysis method using comparison of norms between residual current of HEMP filter and transient electromagnetic conducted susceptibility criteria of equipment, as an alternative method under the condition that performing PCI verification test is limited in HEMP hardened facilities. PCI acceptance test of HEMP filter, transient electromagnetic conducted susceptibility test, and PCI verification test are performed and test results are analyzed.

Objective To investigate the effects of electromagnetic pulse (EMP) on reproductive function of male adult mice. Methods A total of 48 healthy adult male BALB/c mice (8 weeks old) were randomly divided into sham group and EMP group with 24 animals in each group. The mice were whole-body exposed or sham exposed to EMP at 720 kV/m for 100 pulses with 1 Hz repetition rate and 40 ns pulse width. At 1, 7, 14 and 35 d after EMP exposure, the mice were anesthetized and the sperms were collected from the bilateral epididymal tail. After that, the sperm quality including the number of sperms, the ratio of abnormalities and the survival rate was evaluated. In addition, the morphology of testis was observed by HE staining and the diameter of seminiferous tubules was measured by Image J 1.43 u software. The protein level of stem cell factor (SCF) and glial-derived neurotrophic factor (GDNF) in testis tissue were detected by ELISA and Western blot. Results The sperm quality and the morphology of testis did not change obviously at different times after exposing mice to EMP at 720 kV/m for 100 pulses, compared with sham group (P>0.05). The diameters of seminiferous tubules at 1, 7, 14 and 35 d after exposure were (196.85±16.65), (196.79±14.33), (196.35±22.71) and (198.60±25.88) μm in exposed mice, respectively, while (204.31±27.13), (197.07±18.11), (194.37±21.45) and (200.59±19.36) μm in sham exposed mice, respectively. There was no significant difference between two groups (P>0.05). Additionally, the levels of SCF and GDNF in testis tissue between EMP group and sham group had no statistically significant difference (P>0.05). Conclusion Under this exposure condition, EMP couldn′t affect the reproductive function of male adult mice. Key words: Electromagnetic pulse; Mice; Testis; Sperm quality; Seminiferous tubules

In this paper, Frequency-Domain characteristics of three different sets of High-altitude electromagnetic pulse (HEMP) are calculated by Fourier transform. Results prove that the frequency spectrum characteristics, normalization cumulative power energy and power energy spectrum density are relationship with the HEMP waveform parameter. It is possible to be helpful to the HEMP coupling research and the HEMP protection techniques research. Furthermore, the result can be used to expand HEMP generator application in the civil system by changing HEMP waveform parameters. It is possible to use the results to model high-power electromagnetic devices that is non-standard and has short pulse duration.

An efficient field‐to‐line coupling model in the time domain is developed combining the second‐order decoupled multiconductor transmission lines (MTLs) equations and the finite‐element time‐domain (FETD) method for evaluating the electromagnetic (EM) transient response of MTLs over a lossy ground excited by a high‐altitude EM pulse (HEMP). First, the incident HEMP electric fields on the lines are calculated as equivalent distributed sources introduced into the MTLs equations. Then, the discrete FETD equations for the lines against the HEMP, in which the effect of frequency‐dependent parameters caused by the ground impedance is considered, are derived using the FETD method with current as the single iteration variable. Finally, the transient currents induced on the lines are obtained by assembling all the discrete FETD equations into the global FETD equation, and the transient induced voltages on the lines are calculated by discretising the coupled equations with respect to current and voltage. The proposed model is successfully compared with the finite‐difference time‐domain method via several examples. It is then employed to analyse the effect of various parameters on the transient currents including the polarisation and the incident angles of the HEMP, the conductivity, and the relative permittivity of the soil.

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