Novel Measurement System for Grounding Impedance ... - IEEE Xplore

IEEE TRANSACTIONS ON POWER DELIVERY, VOL. 21, NO. 2, APRIL 2006

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Novel Measurement System for Grounding Impedance of Substation Rong Zeng, Member, IEEE, Jinliang He, Senior Member, IEEE, and Zhicheng Guan

Abstract—In order to measure the grounding impedance of a grounding system more precisely and easily, two key problems of the measurement system: the location of the voltage electrode and the elimination of the noise and interference must be conquered. The new theoretical analysis and measurement system of the grounding impedance based on short-current lead wire and a swept frequency ac source is proposed. The compensating position of the voltage electrode to obtain the real grounding impedance is evaluated by analyzing the soil structure, the grounding system under test, and the position of the current electrode. This new system measures the ground impedance at several frequencies other than power frequency, then interpolates them to acquire the ground impedance at the power frequency. The mutual inductance between the potential and current wires is analyzed and eliminated. The industrial computer-based grounding impedance measurement system is developed and the analysis software is programmed. A field test was performed and compared with the traditional method in the substation and the novel system worked well. Index Terms—Grounding impedance, quasi-synchronous sampling algorithm, substation, swept frequency ac source.

electrode and voltage electrode are arranged in 30 included angle) [2]. These methods simplify measurement operations in the field, but they are based on the following hypotheses: a) the electrode wires are long enough, so that the ground system under test can be treated as an ideal hemisphere; b) the soil structure near the ground system is uniform or, in other words, the soil resistivity in different directions is the same. Both of the above hypotheses are difficult to satisfy, thus making the measurement result to deviate considerably from the true value. The theoretical analysis reveals that to obtain the correct grounding impedance value, there always exists a voltage electrode position between the ground system under test and the current electrode, which provides the correct reference potential, regardless of the length of the current electrode wire. So a novel grounding impedance method is proposed in this paper. Compared with the traditional measurements, this computer-aided new method uses relatively short electrode wires and low ac current, while maintaining acceptable measurement error. II. PRINCIPLE OF THE NOVEL MEASUREMENT SYSTEM

I. INTRODUCTION

T

HE substation grounding impedance should be regularly measured to evaluate the availability and safety of the grounding system. Traditional measurements are based on the fall-of-potential method. Generally, in this method, large ac current is injected into the grounding system under test and the voltage between the grounding system, and the voltage electrode is measured. A current electrode is often placed far away from the ground system to decrease the measurement error; therefore, a long electrode wire is needed. Long wires lead to more interference. Moreover, in the case of voltage electrode wire being placed in parallel with the current lead wire, the longer the current electrode lead wire is, the higher the inductive voltage between the voltage and current lead wires is, which makes the entire measure process very difficult [1]. In practice, in China, approximate approaches are recommended, such as the so-called 0.618 method (The voltage electrode is arranged between the grounding system and the current , where is the diselectrode, in the location of tance between the grounding system and the current electrode) and another method, 30 included angle method (the current

Manuscript received April 9, 2004; revised January 25, 2005. This work was supported by the National Natural Science Foundation of China under Grant 50407002. Paper no. TPWRD-00179-2004. The authors are with the State Key Lab of Power Systems, Department of Electrical Engineering, Tsinghua University, Beijing 100084, China. (e-mail: [email protected]; [email protected]; [email protected]). Digital Object Identifier 10.1109/TPWRD.2006.870980

The principle of the proposed new grounding impedance measuring method is to evaluate the compensating position of the voltage electrode to obtain the real grounding impedance of the grounding system according to the obtained soil structure, topological structure of the grounding system under test, and the length of the current electrode’s lead wire. A. Acquiring the Actual Soil Resistivity of Substation Site At some substations where the soil resistivities vary remarkably in different directions, traditional 0.618 method and 30 included-angle method can result in large measurement errors. The solution is to take the actual soil structure into full consideration. The soil resistivity is measured in different directions with the Wenner Four-Electrode Configuration method and the data are stored in the knowledge library for future use during the measurement, and the electrode span is changed from 0.5 m to the value at least equaling the equivalent diameter of the grounding system. Then, the measurement data are processed by the analysis software of the measurement system, which is one component of the software kit, and the soil sublayering result is given, the software can then handle a horizontal or vertical multilayered soil structure. B. Analyzing the Position of Voltage Electrode The potential distribution computation guides where the voltage electrode is to be placed. The compensating point location for a voltage electrode to obtain the real grounding resistance

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Fig. 2. Measuring error caused by voltage electrode location deviation.

Fig. 1.

Ground surface potential distribution.

of the grounding system can be calculated. The principle of the calculation is based on the complex mirror algorithm [3] or by utilizing the vector matrix pencil technique [4]. When computing the potential distribution to obtain the compensating point position, several factors are taken into account, such as the grounding system structure including connected vertical grounding rods with the horizontal grounding grid, the connectedpipeline,orotherstructuresandalakenearby,transmission lines whose grounding wires are connected with the grounding system, a multilayer soil model, and so on. All of these factors influence the potential distribution. No matter how wide the current electrode span is, there theoretically exists such an equipotential plane that the potential of the ground system under test with respect on this plane is equal to the ground potential rise (GPR) when the current electrode is arranged in an infinite way. The ground surface potential distribution along the measurement wires is illustrated in Fig. 1. The ground system is a 100 100-m horizontal square grid, buried in the depth of 0.8 m, with the soil resistivity 200 . Supposing a current of 1 kA is injected into the ground system, and taking infinite distance as the zero potential reference, then the surface potential distribution curve 1 is obtained as shown in Fig. 1, the GPR under this situation is 908.1 V. ( is the length of side, Now adding a current electrode at equal to 100 m) away, for the purpose of simplification, the current electrode is completely the same as the ground grid under test. The 1-kA current is applied between the grounding grid and the current electrode. In this case, the potential distribution is presented by curve 2 in Fig. 1. Apparently, the potential of point A in the middle between the grounding system and the current electrode is zero, the same as the infinite distance. However, to measure the GPR correctly, the voltage electrode should not be placed at point A, because the potential of the ground system under test has been decreased to 844.3 V for the case of a neighbored current electrode. In order to obtain the same GPR when the current electrode is located in the finite distance, the voltage electrode should be moved to point B from point A. Point B is defined as the compensating point of the voltage electrode. As we can see, if the voltage electrode is placed in this point, the measured grounding impedance is the actual one of the grounding system. In an actual measurement of the grounding impedance, ordinarily, the zero potential point at the flattest region of the

potential curve or apparent grounding resistance curve is treated as the compensating point location, so this kind of measurement method would lead to system errors, but when the current electrode is arranged far away from the grounding system, , ( is an equivalent diameter of the such as longer than ground system), the difference of the grounding impedance obtained from the zero point and the compensating one is not big. But for large-scaled substations, arranging the current is very difficult, especially sometimes it is electrode in impossible. So, we proposed this short-current electrode lead wire method. In practical measurement, when the current electrode position is determined and the soil structure is measured, the potential distribution can be acquired, so that the voltage electrode compensating position point can be evaluated. C. Selection of the Length of Current Electrode Lead Wire As discussed above, the long current electrode lead wire makes it easy to determine the position of the voltage electrode and mitigates the measurement error due to location deviation as well. But it also has some problems, such as long wire being difficult to set, it often takes dozens of people during a whole day to lay out and wrap up the wire. Sometimes the operation of a transmission line has stopped and takes the conductors as the measurement wires temporarily. As we can see, longer wire needs higher voltage and a larger power supply capacity; therefore, results are of much higher potential danger to the operators. Short wire is easy to set and decrease the power source capacity. That does not mean the wire can be shortened infinitely, however. The shorter the wire is, the steeper the potential distribution curve is and, in this case, when the voltage electrode is a little deviated from the exact spot, a large error would be introduced. The measurement error introduced for different length of current electrode lead wire is illustrated in Fig. 2. In order to analyze the error, the sample model is selected as below. The voltage electrode deviation is set to be 10 m from the exact location and the sample soil structure composed of two horizontal layers is considered. The reflective coefficient , where and are the resistivities of upper and lower soil layers respectively; is the percentage variety of grounding impedance measurement result when voltage elecis the equivalent ditrode deviates 10 m; 10% of , while is the length of the ameter of grounding system 100 m. current electrode lead wire which is the distance between the

ZENG et al.: NOVEL MEASUREMENT SYSTEM FOR GROUNDING IMPEDANCE OF SUBSTATION

Fig. 4. Fig. 3.

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Function module diagram of the hardware system.

Apparent grounding impedance curve determined by GPS.

current electrode and the grounding system. Obviously, the soil model will affect the result, and the thickness of the upper soil layer relative to is a parameter of the measurement error, because the upper layer thickness will affect the distribution of the potential above the ground. We can observe from Fig. 2, when the length of current electrode lead wire is increased, the measurement error due to voltage electrode location deviation is decreased. And under the same electrode span, the curve with greater has greater . When , if , ; if , . Generally, is often lower than 0.9. Assuming ), when equals to and , the soil is uniform ( respectively, is not beyond 3.5% and 1.5% accordingly. Such a low measurement error is acceptable in practice. On the other hand, if the location errors can be decreased, then the grounding resistance can be measured more precisely with a short-current electrode lead wire. But due to the uneven earth surface, it is easy to bring about the location deviation. Now the electrode location can be precisely set by the global positioning system (GPS). The GPS can control the relative distance between points in 1 m. The measured apparent grounding impedance curves of a 220-kV substation with an area of 170 200 m is shown in Fig. 3, the current electrode distance to grounding system of curve 1 is determined by the length of the current electrode lead wire, but the current electrode distance to grounding system of curve 2 is determined by GPS. The curve obtained by GPS is smooth, and the even region can be easily observed, the grounding impedance of this substation is determined as 0.42 . III. HARDWARE OF THE MEASUREMENT SYSTEM A. Measurement System Structure The measurement hardware consists of the following major components: the swept frequency power source, the data-acquisition and signal processing module, and the personal computer. The functional module diagram of the measurement hardware is shown in Fig. 4. The GPS is used to determine the electrode location. The swept frequency power source is a crucial component of the measurement system. It is based on the sinusoidal pulsewidth modulation (SPWM) technology. It rectifies the power frequency alternating current into direct current first, and then inverts the direct current to the alternating current of

Fig. 5. Data-acquisition and signal-processing system.

the expected frequency. The output frequency spectrum covers a power frequency, ranging from 30 to 200 Hz. The source provides an ac current of almost perfect sinusoidal wave, no larger than 4 A. Four output voltage levels are set to fulfill requirements of different occasions: 50, 100, 150, and 200 V individually. However, for safety reasons, the measurement wire is insulated, and in the measuring process, all of the workers cannot touch and must go away from the remote current electrode for about 10% of . In the first version of the instrument, the microcontroller unit (MCU) is adopted to handle with the data acquisition and signal processing. This MCU controls the data acquisition and preconditions the measurement data. Voltage and current signals are quasi-synchronously sampled first and then multiplied with the quasi-synchronous coefficient table and accumulated in the registers [7]. But as we can see, the pretreatment of the measured raw data is very hard work, and a large amount of data transferring from the MCU module to the personal computer via the serial port is very slow. So in the new version, we use a data-acquisition card with PCI bus, as shown in Fig. 5, which can obtain the required data very fast and stable. And the volume of the whole instrument is much smaller now which results in easy use in the field test.

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TABLE I MEASURED GROUNDING IMPEDANCE UNDER DIFFERENT CURRENT FREQUENCY

Fig. 6.

Typical noise waveform in the field.

A personal computer is used in the field test. The computer shows the man-machine interface, guides the measurement, processes the data, interpolates the grounding impedances, and prints the final result. Though the instrument can work by itself, the computer is not obligatory, it is recommended for fine computation accuracy. And the quasi-synchronous sampling algorithm is used to deal with the periodical current and voltage signal [6], which can get a more precise result with the frequency shifting. As we know, the quasi-synchronous sampling algorithm is suitable for that the frequency of the signal shifts in small scale, so before each sampling, the central frequency is obtained by the hardware counter. B. Elimination of Noises and Interference As we know, the measured voltage between the grounding system and the voltage electrode consists of several components (1) here, and are the frequency of the injected current , is the equivalent inductance of the grounding system, is the mutual inductance between the voltage and current leads, is the other interference component. The grounding and impedance of the grounding system is (2) where the grounding resistance is the resistive component of the grounding impedance. So the grounding impedance cannot be obtained directly from the voltage divided by the injected current . Power frequency noise and its harmonics are major elements which disturb the measurement in the field test. Substations and power plants can produce significant noises. A typical noise voltage waveform between the grounding system and an electrode 100 m away acquired at the Haibowan power plant, which is in the desert of Inner Mongolia, China, is shown in Fig. 6. The peak–peak voltage is approaching 40 V. Such noise is very likely to overwhelm the weak measurement signals. As we can see, the main 300-Hz interference may be produced by a nearby six-pulse rectifier, which is mainly used for a generator exciter or for the dc power supply of the control system in the ac plant or substation. If near an HVdc substation, this would be much more serious.

Effective techniques to eliminate noises include analog and digital filters. An analog active notch filter is embedded into the signal-acquisition module to mitigate the power frequency noise (50 Hz in China). It is constructed by putting a high-pass and a low-pass filter in series. It has a stopband ranging from 48 to 52 Hz with the greatest loss of 50 dB. At first, a Chebyshev-type digital filter is used too. But in the end version, the quasi-synchronous sampling algorithm is used for digital signal processing, since it can get a useful signal in each frequency point more easily. Another key technique is to adopt a frequency-swept power source. Typically, the source can provide an ac of less than 4 A and the frequency spectrum ranges from 30 to 200 Hz. It injects a current at a frequency other than the power frequency into the ground system under test, then the measurement is executed and the grounding impedance under current frequency is measured. When a series of grounding impedance values under different frequencies is acquired, they are interpolated to get the grounding impedance under power frequency. This technique effectively eliminates the interference of residual current of the power frequency in the ground. The measured grounding impedances of a 110-kV substation under different frequencies are shown in Table I. We observed that the measured grounding impedance at 50 Hz is obviously wrong due to power frequency interference, even if the filter is used. In addition to the above hardware and software methods, which are used to eliminate the interference, the mutual incomponent must be eliminated from ductance of the the voltage signal sampled. Since the resistivity of the soil is not equal to zero, the ground cannot be handled as an ideal conducting plate, the mutual inductance between measuring leads with finite length above multilayer soil cannot be easily obtained. However, if the concept of the soil’s complex depth is considered as discussed in [8], the mutual inductance between the current and potential measuring leads can be calculated by the software embedded in the measurement system through the method introduced in [9]. Then, the grounding impedance of the grounding system can be acquired. And all of the measurement steps are guided by the software wizard which will be introduced in the next section. IV. SOFTWARE KIT OF THE MEASUREMENT SYSTEM The measurement software is composed of two main components. One is developed by the Visual Basic for the user interface, digital signal processing, and measurement control. Another software package is developed by C language for the driver


Fig. 8.

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Illustration of the ground system under test.

Fig. 7. Function module diagram of the analysis software kit.

of the sampling board which is plugged into the PCI interface of the PC. The mainframe of the analysis software is illustrated in Fig. 7, which includes the following functions: 1) analyzing the soil structure of substation site according to the apparent soil resistivity data by Wenner Four-Electrode Configuration; 2) accepting the measurement error limits and the surrounding restriction conditions and other grounding system parameters to analyze the compensating point location; 3) proposing measurement scheme; 4) processing measurement data; 5) analyzing the actual grounding impedance. A wizard guides the entire measurement. An easy and friendly man-machine interface has been developed at the PC side. This interface is Windows 95, Windows 98, Windows NT, and Windows XP compatible. The GUI-based, interactive dialog box makes customer input quite easy. The PC side software guides the entire measurement procedure. The soil resistivity of the substation site is measured first and the data are fed to the PC. The upper machine software analyzes the data and provides the soil layering result. Inputting the topological structure of the grounding system, and the length of current electrode’s lead wire, setting the demanded measuring error and other parameters, then the compensating site of the voltage electrode to obtain the real grounding resistance of the grounding system according to the obtained soil structure is analyzed. A suggested measurement scheme is proposed, including in which direction to lay the wires. Set the electrodes and turn on the swept frequency source to inject a current into the grounding system. During the measurement, the pretreated data are transmitted to the PC, and the noise filtering and interpolation operation are executed. The central control software sends control signals to the PCI interface board as well to guide the measurement procedure. Finally, according to the compensating point location, the actual grounding impedance can be obtained from the measured apparent grounding impedance curve, the interference is excluded too. In the meantime, the influence of mutual inductance between the current and voltage measuring wires is excluded according to the introduced method in [10].

Fig. 9. Apparent grounding impedance curve by the high-current method with a long current electrode lead wire.

V. FIELD VERIFICATION The novel substation grounding impedance measurement system has been tested in the field under the serious electromagnetic-interference (EMI) condition. The field test was performed at the grounding system of the Haibowan 220-kV Power Plant. The structure of the grounding system is shown in Fig. 8. Its total area is 450 300 m, the black points in Fig. 8 express vertical grounding rods with a length of 40 m. In order to verify the preciseness of a short-current electrode lead wire method, the tested result obtained by the potential fall method, in which the current electrode lead wire length is ( is the equivalent diameter of the grounding system) and a very high current supplied by a high-voltage phase conductor was used. The calculated result is shown for comparison too. The length of the current electrode lead wire for the high-current ) for a short-current method is 1620 m, and 400 m (about electrode lead wire method. The voltage and current lead wires are arranged in parallel with a 5-m span. The tested apparent grounding impedance curve is shown in Fig. 9, the applied power frequency ac current is 10 A, and the interference of unbalance current flowing in the soil is eliminated by the phase reverse method. After the interference is eliminated, the grounding impedance obtained from Fig. 9 by a high current method is 0.18 . The tested apparent grounding impedance curve with the measurement system and method developed by us is shown in Fig. 10. Obviously, we cannot directly obtain the actual grounding impedance from the curve. In order to acquire the compensating point, the analysis software kit, shown in Fig. 7, is used by the guide of the wizard. First, the soil resistivity data of substation location was measured with the Wenner Four-Electrode Configuration method as

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REFERENCES

Fig. 10. Apparent grounding resistance curve by the short-current electrode lead wire.

Fig. 11.

Measured apparent soil resistivity of the substation site.

shown in Fig. 11. Second, the soil structure of the substation site is analyzed and which can be divided into three horizontal layers, the soil resistivities are 114, 3812, and 74 m, respectively for top, medium, and bottom layers, and the thickness of the top and medium layers is 2.4 and 16.8 m, respectively. Third, with the input soil structure, grounding system parameters, and current electrode data into the analysis software, the compensating point location is obtained to be 220 m from the grounding system. From Fig. 9, the obtained actual grounding impedance by the proposed method is 0.185 , very close to the result 0.18 of the high-current method with a long lead wire mentioned before. By the proposed method and measurement system illustrated above, it is easy to acquire the grounding impedance due to very short current electrode lead wire and low current. VI. CONCLUSION A novel solution to measure the substation grounding impedance using low current and short measurement wires is proposed, which can make the measurement much easy. Compared with traditional methods, the same task which will take ten people to work the whole day to measure the grounding system of a 500-kV substation by traditional method in China, the proposed method now only needs two people to work 2 or 3 h. The industrial computer-based, swept frequency power source-cored intelligent hardware system is constructed. And the assistant analysis software is developed, which cannot only supply the whole measurement scheme, but can also analyze the measurement input signal and supply the final result. The measurement system is applied in the field and keeps ideal stability and accuracy, and the measurement result has good agreement with the traditional method with long current wire and high current.

[1] A. P. S. Meliopoulos et al., “A PC based ground impedance measurement instrument,” IEEE Trans. Power Del., vol. 8, no. 3, pp. 1095–1106, Jul. 1993. [2] IEEE Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System, IEEE Std. 81-1983. [3] R. Zeng, “Research on grounding technology for substations and power plants in high soil resistivity area,” Ph.D. dissertation, Dept. Elect. Eng., Tsinghua Univ., Beijing, China, 1999. [4] J. Zou, R. Zeng, J. L. He, J. Guo, Y. Q. Gao, and S. M. Chen, “Numerical Green’s function of a point current source in horizontal multi-layer soils by utilizing the vector matrix pencil technique,” IEEE Trans. Magn., pt. 2, vol. 40, no. 2, pp. 730–733, Mar. 2004. [5] P. S. Filipski, “The systematic errors of a time-division power converter under sinusoidal and nonsinusoidal conditions,” IEEE Trans. Power Del., vol. PWRD-1, no. 3, pp. 1615–1619, Jul. 1986. [6] B. Zhang, “Research on Intelligent Measurement System for Grounding Resistance of Substations and Power Plants,” M.Sc. thesis, Dept. Elect. Eng., Tsinghua Univ., Beijing, China, 2000. [7] X. Dai et al., “Quasisynchronous sampling algorithm and its application,” IEEE Trans. Instrum. Meas., vol. 43, no. 2, pp. 204–209, Apr. 1994. [8] A. Deri, G. Tevan, A. Semlyen, and A. Castanheira, “The complex ground return plane: A simplified model for homogeneous and multi-layer earth return,” IEEE Trans. Power App. Syst., vol. PAS-100, no. 8, pp. 3686–3693, Aug. 1981. [9] E. J. Rogers and J. F. White, “Mutual coupling between finite lengths parallel or angled horizontal earth return conductors,” IEEE Trans. Power Del., vol. 4, no. 1, pp. 103–111, Jan. 1989. [10] R. Zeng, J. L. He, Y. P. Tu, J. B. Lee, S. H. Chang, Y. Q. Gao, J. Zou, and Z. C. Guan, “Influence of overhead transmission line on grounding impedance measurement of substation,” IEEE Trans. Power Del., pt. 2, vol. 20, no. 2, pp. 1219–1225, Apr. 2005. Rong Zeng (M’02) was born in Shaanxi, China, in 1971. He received the B.Sc., M.Eng., and Ph.D. degrees in electrical engineering from Tsinghua University, Beijing, China, in 1995, 1997, and 1999, respectively. Currently, he is an Associate Professor and Deputy Director in the Department of Electrical Engineering, Tsinghua University, where he was a Lecturer. His research interests include high-voltage technology, lightning and grounding technology, electromagnetic (EM) measurement, and EM compatibility. Jinliang He (M’02–SM’02) was born in Changsha, China, in 1966. He received the B.Sc. degree in electrical engineering from Wuhan University of Hydraulic and Electrical Engineering, Wuhan, China, in 1988, the M.Sc. degree in electrical engineering from Chongqing University, Chongqing, China, in 1991, and the Ph.D. degree in electrical engineering from Tsinghua University, Beijing, China, in 1994. Currently, he is the Vice Chief of the High Voltage Research Institute, Department of Electrical Engineering, Tsinghua University, Beijing. He became a Lecturer in 1994 and an Associate professor in 1996 in the Department of Electrical Engineering, Tsinghua University. From 1994 to 1997, he was the Head of High Voltage Laboratory, Tsinghua University. From 1997 to 1998, he was a Visiting Scientist in the Korea Electrotechnology Research Institute, Changwon, Korea, involved in research on metal-oxide varistors and high-voltage polymeric metal-oxide surge arresters. In 2001, he was promoted to Professor in Tsinghua University. His research interests include overvoltages and electromagnetic compatibility in power systems and electronic systems, grounding technology, power apparatus, dielectric material, and power distribution automation. He is the author of five books and many technical papers. Dr. He is a Senior Member of the China Electrotechnology Society and a member of the International Compumag Society. He is the China representative of IEC TC 81, vice chief of China Lightning Protection Standardization Technology Committee, and member of the Electromagnetic Interference Protection Committee and Transmission Line Committee of the China Power Electric Society, member of the China Surge Arrester Standardization Technology Committee, and member of the Overvoltage and Insulation Coordination Standardization Technology Committee and Surge Arrester Standardization Technology Committee in Electric Power Industry. Dr. He is the Chief Editor of the Journal of Lightning Protection and Standardization (in Chinese).


Zhicheng Guan was born in Jilin, China, in 1944. He received the B.Sc., M.Eng., and Ph.D. degrees from the Department of Electrical Engineering, Tsinghua University, Beijing, China, in 1970, 1981, and 1984, respectively. From 1984 to 1987, he was a Lecturer and the Director of High Voltage Laboratory, Department of Electrical Engineering, Tsinghua University. From 1988 to 1989, he was a Visiting Scholar with the University of Manchester Institute of Science and Technology (UMIST), Manchester, U.K. From 1989 to 1991, he was an Associate Professor and the Director of High Voltage Laboratory at UMIST. In 1991, he was promoted to Professor. From 1992 to 1993, he was the Head of the Department of Electrical Engineering, Tsinghua University. From 1993 to 1994, he was the Assistant President of Tsinghua University, and from 1994 to 1999, he was the Vice President of Tsinghua University, and since 1999, he has been the Vice President of the Tsinghua University Council. He is the author of many academic papers. His major research fields include high-voltage insulation and electrical discharge, composite insulators and flashover of contaminated insulators, electrical environment technology, high-voltage measurement, and application of plasma and high-voltage technology in biological and environment engineering. He owns many titles in academic societies. Dr. Guan is the Vice President of the Chinese Society for Electrical Engineering, and Vice President of the China Electrotechnical Society, Vice Chairman of the High Voltage Technology Committee of the Chinese Society for Electrical Engineering, and Vice Chairman of the Ceramics Institution and Environment Technology Institution of the China Electrotechnical Society. He is a member of Environment Protection Institution of the China Electrotechnical Society, member of the China Insulator Standardization Technology Committee, member of the Executive Council of Chinese Association of the Power Transmission Industry, a member and Chief Expert of the Environmental Technology Research Center of the Mechanical Industry, a member and Expert Panel of the Pollution Flashover Prevention of the Electrical Power Industry in China, a member of the Executive Council of China Association of the International Education Exchanges, chairman of the High Education Committee, a member of the Executive Council of the China Association of Continuing Engineering Education.

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