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In the two-stage converter such as PV renewable energy system, the second harmonic fluctuation exists in the DC voltage due to the power coupling between the DC-link and AC system. The second harmonic voltage in the DC link could increase the system loss and decrease the stability of the converter system, and its generation process and transmission mechanism are analyzed in this paper. The mathematical expression of second harmonic voltage in DC-link has been derived. A second band passing filter (BPF) feedback control loop is used to feedback the second harmonic ripple voltage in DC link into the statable modulation index. This strategy can decrease the second harmonic voltage in the DC-link and the third harmonic voltage in the AC sides. Finally, the control parameters are implemented using a simulation platform, and the match suppression strategy is validated by the simulation results.

In this paper, active filters are embedded in the grid-connected converter control of Type-IV wind turbines to reduce harmonic voltage amplification in offshore wind power plants (WPPs). The extra element theorem is employed to tune the active filters and determine the stability margin. Active filter tunings that satisfactorily reduce harmonic voltage amplification yet provide sufficient stability margin in the augmented system are identified. A running example is performed on a 270 MW offshore WPP comprised of 3-MW wind turbines implemented in real-time simulation as hardware-in-the-loop. Both converter and grid voltage harmonics are suppressed at WPP buses to below the stipulated planning levels.

This paper puts forward power measurement of harmonic signal by using an efficient algorithm. The obscure power segments and other power quality lists are estimated by definitions in the IEEE Standard 1459–2000. Spectrum of harmonic voltage and current signals are estimated independently, further the computations are made. Both PC reproductions and research center testing are finished looking at the proficiency (efficiency) of the proposed calculation. The real signals from Chroma programming are inputted through the Data Acquisition (DAQ) card and the results of the algorithm are viewed in LabVIEW. This algorithm is accurate and efficient, making it suitable for real-time applications.

Leakage current measurement is the most reliable and effective method for condition monitoring of overhead insulators deployed in the field. However, a major challenge in the leakage current based insulator monitoring is to interpret the indices extracted from the leakage current measurements under varying harmonic content in system voltage. This paper reports the possibility of employing the instantaneous value of time-integral of leakage current as a low-sensitive parameter for the monitoring of leakage current in overhead insulators in the presence of voltage harmonics. It has been shown that any change in the harmonic content of the system voltage has a significant influence on the harmonic characteristics of the leakage current, but has a comparatively less severe effect on the time-integral. The monitoring technique has been validated through laboratory recorded experimental data and incorporated in an online measurement device that has been tested in the laboratory.

Nowadays permanent magnet synchronous machines those frequency-controlled from stator side with frequency inverters made on the basis of power transistors or fully controlled thyristors, are widely used as motors and generators. In future they are also promising a good application in transport, including marine. Modern frequency inverters are equipped with a control system based on sine-shaped pulse width modulation. While shaping the voltage in the output of the inverter, in addition to the fundamental harmonic, higher harmonic components are also included in the voltage shape, which certainly affect the operating parameters of the generator (electromagnetic torque, power, currents). To determine this effect the modeling and investigation technique of higher harmonic voltages in the "electric network – frequency converter – synchronous machine with permanent magnets" system has been developed. The proposed equations of a frequency-controlled permanent magnet synchronous machine allow relatively simply reproduce the harmonic composition of the voltage in the output of a frequency inverter equipped with the control system based on a sinusoidal pulse width modulation. The developed research technique can be used for inverters with any number and composition of voltage harmonic components feeding a stator winding of a permanent magnet synchronous machine. On a particular case, the efficiency of the research technique of the higher harmonics influence on the operating parameters of the generator has been demonstrated. At the same time, the study has been carried out taking into account the shape of the voltage curve feeding the windings of the synchronous machine containing in addition to the fundamental harmonic the 8, 10, 11, 13, 14 and 16-th harmonic components, and the rated active power of the synchronous machine has been equal to 1 500 kW.

High voltage direct current transmission (HVDC) has been widely used in China in recent years due to its advantages of large transmission capacity, long distance, and low cost. It is significant to establish models for harmonic analysis in HVDC system. The switching function is used to get DC side harmonic voltage source, and the leakage inductance of transformer in both rectifier and inverter stations is equivalent to the DC side. A DC side harmonic equivalent calculation circuit for 6/12-pulse HVDC system is proposed accordingly. Using the simulation examples built in PSCAD/EMTDC, the correctness of the proposed model is verified.

In a three-level (NPC) converter, the voltage imbalance problem in the DC-link capacitors is major issue. This paper proposes the DC-link capacitor voltage imbalance compensation method, where a common offset voltage is injected for a multi-module NPC inverter. The offset voltage consists of a harmonic voltage and a voltage difference between the upper and lower capacitors. The proposed method does not require any hardware modification, so that it is easily implemented. In order to show the effectiveness of the proposed balancing method, theoretical analysis is provided to balance the voltages, and both the simulations and the experiments were carried out to show that the voltage difference of the DC-link was decreased by the proposed method.

The oil-paper insulation of valve-side windings in a high voltage direct current (HVDC) converter transformer is subjected to both complicated voltage and severe thermal stresses. Partial discharge (PD) occurring in oil-paper bounded cavities is influenced by voltage stress type as well as temperature. This paper presents PD behaviors in an oil-paper bounded gas cavity under pulsating DC voltages. The voltage across the gas cavity and PD inception voltages at different test conditions are analyzed. Influences of temperature on statistical PD distributions and parameters are also presented. A numerical model is used to interpret PD behaviors under pulsating DC voltages and various temperatures. Experimental results and theoretical statements show that the temperature exhibits a great influence on the behaviors of cavity discharge under pulsating DC voltages. Volume resistivity, gas pressure, charge decay time constant, and electron generation rate are the primary parameters influencing PD behaviors at different temperatures.

We describe a mathematical model of electrophysical processes occurring in the system consisting of a transistor inverter, an oscillatory circuit, a step-up transformer, a long feedline, and a barrier-discharge lamp. We propose and test a method for effective transmission of a high-frequency voltage from a power supply to the barrier-discharge lamp via a long coaxial line in which the voltage was applied to the electrodes of the lamp in the form of harmonic voltage bursts at a frequency close to the self-resonant frequency of the excitation system.

The most monitoring techniques of metal oxide surge arresters are based on harmonics analysis of resistive leakage current. Therefore, the extraction of resistive component from total leakage current is required. Up to now, several methods have been proposed for resistive leakage current extraction such as time-delay addition method. This method is only able to separate accurate resistive component under pure sinusoidal applied voltage. An improved time-delay addition method is proposed in this paper which is able to extract surge arrester resistive component under applied harmonic voltage. To accomplish this purpose, experimental tests have been performed on 20 kV surge arrester and obtained voltage and leakage current signals have been applied to the proposed and previous algorithms for resistive component extraction. In addition to investigate the ability of proposed algorithm, a typical surge arrester has been simulated in ATP-EMTP software and total leakage currents have been applied to both algorithms for resistive leakage current extraction. Results show that the proposed method is able to extract resistive component under applied harmonic voltage more accurate than previous one. Therefore, it is an improvement with respect to previous one that only works for sinusoidal voltage.

We have proposed an islanding detection method using the harmonic current as an active signal. In particular, in order to inject the active signal efficiently, we have proposed a method to synchronize the harmonic voltage caused by the active signal of DG with the harmonic voltage caused by the harmonic current of the load. To verify the validity of the proposed methods, we performed the simulation by PSCAD/EMTDC and the calculation by circuit theory. We clarified that the synchronous injection can be greatly reduced the islanding detection time.

This paper presents an assessment of voltage distortion, flicker and slow voltage variation caused by a distributed rooftop photovoltaic system in the low voltage distribution network at the campus of Universidad de El Salvador. Individual triplen harmonic voltage levels and longterm flicker index levels assessed in field measurements at the campus exceeded the compatibility levels established in most international power quality standards. The assessments also show a growing trend in all triplen harmonic voltage levels, short term flicker severity index and long-term flicker severity index levels, after the photovoltaic generation started operation.

The converter stations of different HVDC systems located in the adjacent networks, which have short electrical distance, forming a Multi-HVDC system. In the Multi-HVDC system, exists the harmonics interaction. This paper establishes the Multi-HVDC harmonic impedance model. The harmonic self-impedance, harmonic transfer impedance and harmonic transfer coefficient are defined to measure the influence of each harmonic current on the harmonic voltage of converter stations; giving the concept of harmonic voltage transfer amplification and transmission reduction. Taking Yin Chuandong Station and Lingzhou Station as examples, which belong to the Ning-Dong and Ning-Zhe Multi-HVDC systems. Calculate the harmonic self-impedance, harmonic transfer impedance and harmonic transfer coefficient of two converter stations. The results indicate that 3rd, 5th, 7th harmonics have greater impacts on the converter station. When the 5th harmonic current is injucted into the Ling Zhou Station, the harmonic voltage induced on Yin Chuandong Station is higher than that of in Lingzhou Station. After transmitted through the AC system, the effect of harmonic current on the remote converter station is increased, the voltage transfer amplification has occurred. All the results are verified by PSCAD simulation.

Industrial Static Var Generator (SVG) is typically applied at or near the load center to mitigate voltage fluctuation, flicker, phase unbalance, non-sine distortion or other load-related disturbance. Special attention is paid to the influence of grid harmonic on SVG current, the harmonic grid voltage causes not only the AC current distortion but also the DC voltage fluctuation. The harmonic voltage decomposition algorithm and DC voltage control are also introduced. All these analyses can guide the practical applications. The simulation results verify the feasibility and effectiveness of the present control strategy and analyses.

It can be predicted that the proportion of wind power in the power grid will gradually increase with the maturity of the application technology in wind power. Based on the development of wind power, this paper is to research the impact of wind farm on power grid. Matpower is used to calculate the buses voltage, reactive power and power loss of the IEEE-33 network with two wind farms. And matlab is used to analyze the harmonic voltage influence to the network. The results show that the active power of the wind farm has a significant effect on the distribution network. The quantity of harmonic current injected into the system is also maximal during rate wind power output, which must be tested and controlled strictly.

The limitation of harmonic currents emitted by individual equipment and customer installations is essential in order to maintain harmonic voltages below compatibility or planning levels and consequently to ensure Electromagnetic Compatibility (EMC). At present, a large variety of methods exists worldwide for calculating harmonic emission limits, majorly expressed as harmonic currents. A systematic search on available methods has been performed for more than 70 countries from all over the world. Finally 16 individual methods for low voltage (LV), medium voltage (MV) and high voltage (HV) networks have been selected for a detailed quantitative comparison based on a probabilistic approach. This paper compares harmonic emission limits of the different methods for individual customer installation and is focused on generating installations. The first part provides details about the framework of comparison; the second part summarizes the results for the different voltage levels.

This paper has carried on the theoretical analysis and experimental research on the different impacts of positive, negative and zero sequence harmonic voltage measurement using three single-phase potential transformers with neutral point grounded through a ferroresonance eliminator. First, the influences of the different excitation characteristics among the three PTs and the non-linear excitation characteristics of a single-phase PT on different sequences harmonic voltage measurement are analyzed theoretically. Then the physical experiment platform has been designed, and the experiments of three-phase PTs on different sequences harmonic voltage measurement are carried on. The experiment results verified that the influences of three-phase PTs on different sequences harmonic measurement are not the same at this grounding mode.

In the photovoltaic power generation system, the harmonic voltage of the point of common coupling (PCC) is determined by system disturbance, local load and photovoltaic power generation system itself together. Based on the fluctuations of this harmonic voltage, a new islanding detection method for the PV system is proposed. By extracting the higher harmonic components from the wavelet transformation of point of common coupling (PCC) voltage, and then taking its fluctuations as the islanding identification and detection index, non-detection zone (NDZ) can be eliminated, without a plus disturbance. According to IEEE Std.1547, simulated verification of the proposed method is accomplished in the ideal photovoltaic grid system. When the PCC voltage and frequency are within the normal range, it can not only give a fast and accurate detection to the occurrence of islanding, but also identify the false islanding, such as voltage dips and switching loads, effectively avoiding false detection caused by the false islanding.

This paper presents the rules of harmonic penetration in Zhengzhou harmonic voltage level. National standards limit the harmonic voltage distortion level in the buses, so study the UHV AC/DC hybrid system is significant to power grid. In order to find out the harmonic voltage level near Zhengzhou converter station, a method has been proposed in this paper, including the models of radiation power grid, load characteristics and converter station's AC filter. Finally, according to Zhengzhou converter station power frame sets up a detail model in the simulation software packages PSCAD/EMTDC to study the law of harmonic penetration.

In this study, a new method is proposed to evaluate the utility harmonic impedance and the harmonics responsibilities at the point of common coupling. The former task is accomplished by involving the harmonic phase angles in the data correlation method, and the latter one is done using an approach based on the fluctuation of the background harmonic voltage. An important advantage of the method is to take the load harmonic impedance into account in appropriate manner. The performance of the proposed method is verified using simulation studies for different cases and also field measurements. Long-term measurement data are used to determine the harmonic contribution of the industrial customers and short-term measurement data are utilised to validate the effectiveness of the proposed method. Totally, simulation analysis and case study demonstrate more accuracy of the proposed method in comparison with other present methods.

The purpose of the analysis of measurement results of harmonics presented in this paper is to predict the potential dangers after installation of capacitor banks in a medium-voltage (6 kV) network of the Kolubara open pit mine. Although the measured values for most of the harmonic voltages are lower than the maximum allowed values for medium-voltage networks, there is a risk of resonant occurrences of certain harmonics. It is shown that the resonant harmonic currents of the 11th to 25th orders can increase up to 10 times. These increases in harmonic currents could not overload network elements, but they could lead to overload and outage of the power capacitors. It is particularly important to note that the (quasi-) resonant phenomenon, which is common for harmonics between the 11th and the 25th order, is difficult to avoid without performing additional measures.

This paper uses data obtained from laboratory measurements of typical appliances such as Refrigerator, TV set to verify whether these non- linear loads behave similar to current harmonic sources or voltage-type harmonic sources. Inverter is used as input power supply. The output of inverter 230V is connected to Residential & Commercial Loads through a distribution transformer. Based on the measurements and additional simulations, and comparison from the tabular form it is stated that residential and commercial electronic loads behave essentially like harmonic voltage sources. This behavior helps to explain why shunt compensators and filters may even increase the harmonic current content in the feeder.

This paper deals with a new concept for calculating DC harmonic voltages and currents of line- commutated HVDC systems. In contrast to the conventional method, this method is useful for BTB (Back-To-Back) HVDC systems without smoothing reactors or PTP (Point-To-Point) with very short transmission line. This method proposes a new direction for HVDC system design and analysis. The proposed method is applied to a 50 Hz/60 Hz BTB test system and a synchronized BTB test system. After simulation and verification, the new results are introduced.

This paper develops an enhanced harmonic voltage compensator which is implemented with the aid of two repetitive controllers (RCs) in order to improve the output voltage performance of stand-alone distributed generation (DG) systems. The proposed harmonic voltage compensator is able to maintain the DG output voltage sinusoidal regardless of the use of nonlinear and/or unbalanced loads in the load side. In addition, it can offer good steady-state performance under various types of loads and a very fast dynamic response under load variations to overcome the slow dynamic response issue of the traditional RC. The feasibility of the proposed control strategy is verified through simulations and experiments.

This paper presents a novel method for determining the harmonic emission responsibilities of utility and customer at the point of common coupling (PCC). The proposed approach is based on robust partial least squares regression (robust PLS), which estimates system harmonic impedance by utilizing the signals of harmonic voltage and current measured synchronously at PCC. Consequently the harmonic emission responsibilities are calculated. The presented method reduces or removes the effect of outlying data points. The simulation and the practical engineering results indicate that the proposed method is valid and feasible.

In the series hybrid active power filter (SHAPF) based on fundamental magnetic flux compensation (FMFC), the harmonic voltage across the magnetising inductance of the series transformer will disturb the inverter output current and worsen the filtering effect of the SHAPF. However, this influence caused by harmonic voltage was ignored in the previous research. Therefore there is blindness and casualness in the parameter selection of the SHAPF based on FMFC. Taking a 10 kV, 1 MVA industrial application of the SHAPF in a manufacture factory in Guangdong Province as an example, this study establishes the accurate global mathematical model of the SHAPF. Furthermore, based on the proposed global mathematical model, the series transformer parameters are analysed in detail to show its influence on the filtering performance of the SHAPF. This mathematical model can be used as foundations of the parameter selection of the SHAPF. Finally, an engineering prototype is manufactured and applied. The practical experimental results verify the theoretical analysis.

As the additional injection type hybrid active power filter (IHAPF) may exist fundamental circulation between the active part and fundamental harmonic branch, a new topology of injection type hybrid active power filter is proposed to enhance the safety of IHAPF in the paper, this paper discusses the principle of fundamental circulation and the advantage of the novel structure on harmonic voltage of series resonant subcircuit.

A methodology of diagnosing the winding insulation defect according to data of transient voltage and current from the impulse voltage test is put forward in this paper. Lightning impulse test for transformer is divided into half-wave and full-wave at the moment. According to the full voltage and reduced voltage at two pressure processes. The transient voltage and current from the impulse voltage test can be divided into Series of harmonics. The insulation defect is diagnosed by dividing impulse voltage and current into series of harmonic and structuring discriminant function according to the longitudinal ratio method and cross ratio method for the corresponding period of harmonic voltage and current. The methodology is also applicable to diagnose whether there are insulation damage in the windings those have passed the lightning impulse test.

When distributed generators such as photovoltaic (PV) systems spread widely in distribution networks, it is important to detect islanding caused by power system fault for ensuring electrical safety. We developed the nonlinear magnetizing characteristics model of a pole transformer for analyzing islanding-prevention of PV system. Basic experiments of the islanding-detection were conducted by using the RLC resonant circuit for verification of the developed model. Analytical results by the proposed model agreed well with experimental results.

The detection of harmonic source is important for harmonic responsibility sharing and mitigation. In this paper, a new indice for harmonic source detection is investigated. This indice is a power component decomposed from apparent power recommended by IEEE Std. 1459-2010, named harmonic distortion power. The theoretical effectiveness of this indice for the detection of harmonic source is analyzed by the positive correlation between instantaneous power and apparent power components. Then simulation case studies in various background harmonic voltage conditions and measurement test results of typical household loads show that this indice can provide useful information for harmonic source detection in certain conditions.

This paper studies the impact of different plug-in electric vehicles on network harmonic distortions, both at low frequencies and at high frequencies. Extensive measurements have been conducted in four different EVs (both regular passenger vehicles and electric buses), charged through different stations. Fast and slow, commercial and residential charging events were monitored. The collected set of measurements has shown that EV charging does have an impact on harmonic distortion levels. At low frequencies, harmonic voltages are below 4.0% and, therefore, EV impact is limited and unlikely to cause violations of harmonic distortion limits established in the Brazilian regulation (i.e., 10%). At high frequencies, voltage distortions of up to 1.0% of 60 Hz voltage were observed; however, the results are still preliminary and do not offer a reliable conclusion on whether such distortions have the potential to become a concern for utilities or not.

The limitation of harmonic currents emitted by individual equipment and customer installations is essential in order to maintain harmonic voltages below compatibility or planning levels and consequently to ensure Electromagnetic Compatibility (EMC). At present a large variety of methods exists worldwide for calculating harmonic emission limits, majorly expressed as harmonic currents. As starting point for the revision of the methods currently used in Germany, a systematic search on available methods has been performed for more than 70 countries from all over the world. Finally 18 individual methods have been selected for a detailed qualitative comparison based on a set of characteristics, like voltage level, frequency range, allocation principle or network topology. The paper summarizes the results of the survey and provides an initial quantitative comparison of the selected methods based on two particular examples.

International audience; To keep a high level of power quality, Distribution System Operators (DSOs) must keep harmonic voltage levels under limits specified in standards. These harmonic voltages are due to non-linear equipment connected inside installations, which inject harmonic currents into public networks. In order to apply emission limits per installation, DSOs need to have an accurate and reliable indicator to assess the harmonic emissions of an installation. In this paper, a comparative analysis of two definitions for assessing the harmonic emissions of installations is presented. Their respective advantages and drawbacks are pointed out.

Novel tunable distributed harmonic Voltage Controlled Oscillators (VCOs) are reported here for generation of 2nd or 3rd or both 2nd and 3rd harmonic frequency microwave/millimeter-wave signals, designed using Distributed Oscillator (DO) and achieved frequency tuning by body bias. The above generation of signals is become possible by the use of combination of innovative gain cell (i.e. amplifier), CPW lines and selection of the value of peaking inductor in the gain cells. The highest power output of the oscillator is at the third harmonic frequency of 41.84 GHz using low cost industrystandard 180nm CMOS which has a cut-off frequency of 50 GHz.

In this paper, the explosion accident of a 220kV current transformer in a 220kV substation is studied. It uses method of scene investigation and test to analyses the accident based on the principle and characteristics of current transformer. Through the analysis, this paper holds that reducing in main insulation electrical strength caused by Long-term high harmonic voltage and main insulation breakdown caused by flicker impact are main causes of the accident. And it also proposes a variety of management methods and technical measures to avoid this kind of accident. This paper provides a reference for the analysis of the same type of accident.

In this study, we examine the relationship between harmonic voltage injection, acoustic noise, and position estimation performance in a PMSM when a position-sensorless control method involving harmonic voltage injection is used at low speeds. Further, we propose a novel control method for voltage injection; this method can be used to reduce acoustic noise in the motor. The proposed control method is verified by performing numerical simulations and carrying out experiments using a four-pole, 2-kW, 2100-rpm IPMSM (interior permanent-magnet synchronous motor). © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(3): 49–56, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21246

This paper proposes a blend control scheme of APF based on harmonic voltage to solve the problem that load current detection APF cannot change the harmonic impedance in distribution system. In addition, based on the relationship between the rated volt-ampere of APF and the load volt-ampere, the conductance value could automatic adjustment. Computer simulation and laboratory system are designed and constructed to verify the validity and effectiveness of the shunt active filter equipped with the blend control. The shunt active filter with blend control not only can compensate the nonlinear load harmonic current but also can help to damp the harmonic voltage in distribution system.

Instead of injecting harmonic currents to compensate those drawn by distorting loads, in this paper a shunt active filter is used for generating harmonic voltages to compensate harmonic voltages at the point of common coupling; the main advantage in using such a compensation approach is that, when the aim is to reduce or eliminate the harmonic voltages at the point of common coupling only one active filter is required. For determining the harmonic voltages such a filter must generate, two simple and practical methods are proposed in this paper; the effectiveness of these methods was evaluated using a 1-kW prototype of an active filter operating according to the shunt harmonic voltage compensation approach. In addition, the laboratory results were comparable to those obtained with the ATP-EMTP simulation software.

The main contents of this paper are the PQM system construction case and distribution system harmonic voltage analysis. The PQM system has constructed by KEPCO in order to investigate power quality of distribution power system for new power quality standard of KEPCO. In result, we have confirmed that voltage harmonic measurement value of the high voltage contract customer 8 households is suitable the KEPCO harmonic standard tentative plan. And the voltage harmonic value of distribution line end side is not always more high than source side by harmonic current offset effect. In the future, acquired data by season, region, load from the PQMS will be used on the resonable harmonic standard enactment in KEPCO.

A stator earth fault of a generator is the result of a lack of isolation between the stator winding of a generator and its iron core. In the last decades a number of different philosophies have been developed. With the latest experiences on the behaviour of the 3rd harmonic voltages of a generator the differences of applicable philosophies will be discussed and an approach to a sustainable solution will be outlined.

In this paper a steady-state model of a single-phase power supply is presented, The model takes into account the influence of feeder harmonic voltages on the non-linear load behaviour. With this model we can observe that, when the distorting load consumption is important, the harmonic interaction must be considered in order to obtain correct results. This model has been implemented in a harmonic load-flow program in order to perform harmonic studies in network and industrial installation.

The synchronization between DG and microgird is required in order to prevent high inrush current. This high inrush current may trigger the protection or danger the facility in the system. On the other hand, anti-islanding inverters shall always detect islanding condition when they connect to microgrid. It is required that disconnecting from microgrid in two seconds whenever islanding occurred. General speaking, there are two method to detect islanding-passive and active method. This paper developed a voltage-controlled inverter which could connect to microgrid with synchronization and detect islanding condition actively. According to second harmonic voltage injection method, the proposed inverter detects the second harmonic current to decide whether islanding is happened.

Characteristics of the current emission for new developed devices are changing resulting in lower low order harmonics and an increase in high order harmonics. For the low voltage network this results in an increase in high order harmonic voltages, violating more often the limits for the harmonic voltages at the 15th and 21th order harmonic. To improve this situation harmonic current could be reduced, network impedance could be decreased or the harmonic voltage limits could be increased. Since there are no complaints regarding these higher harmonic voltages, this paper presents an alternative approach to update these harmonic voltage limits.

Keywords: Harmonic; electronic instrument transformer; Harmonic error measurement system Abstract. A harmonic error measurement system which can simulate the actual operating conditions of electronic instrument transformer was established for electronic instrument transformer harmonic error measurement. The system consists of High-power current and voltage harmonic source which is used to output fundamental and harmonic signal, harmonic voltage and current standard device and harmonic analyzer. The results indicate that after superposing the fundamental and harmonic, ratio and phase error of electronic current transformer (ECT) becomes larger with increasing frequency; ratio error of electronic voltage transformer(EVT) increases with the increasing harmonics frequency, but EVT phase error changed to negative value at rated current, 150Hz frequency.