The invention discloses a distributed transmission network power-frequency electromagnetic field analysis method and belongs to the technical field of electromagnetic fields. The method comprises constructing a distributed transmission network model according to the nodes, loops, and voltage and current on the loops of a real distributed transmission network; then constructing a simulation-domainmodel according to the environment where the real distributed transmission network is located; further simulating and calculating a power-frequency electromagnetic field generated by the distributed transmission network in space, revealing the law of the power-frequency electromagnetic field generated by the distributed power transmission network by the visualization of the power-frequency electromagnetic field simulation data, and further revealing the conduction law of the power-frequency electromagnetic field generated by the distributed power transmission network under different media by calculating the divergence and rotation of the electromagnetic field. The method is applicable to the power-frequency electromagnetic field simulation of a complex distributed transmission network, andfills the blank in relevant technology.

Distributed transmission network power-frequency electromagnetic field analysis method

The invention relates to a zero-flux current sensor, which comprises a magnetic probe winding, a signal processing circuit, a compensating current power driving circuit, an abnormity monitoring circuit, a regulating switch and a negative feedback regulating circuit. The signal processing circuit is in electrical connection with the magnetic probe winding; the compensating current power driving circuit is electrically connected with an output end of the signal processing circuit and the magnetic probe winding; the abnormity monitoring circuit is in electrical connection with the magnetic probewinding; the regulating switch is in electrical connection with the signal processing circuit; the negative feedback regulating circuit is electrically connected with an output end of the abnormity monitoring circuit and the regulating switch and is used for controlling on-off states of the regulating switch according to operating states, acquired by abnormity monitoring circuit in detection, of the magnetic probe winding to further control output signal reverse of the signal processing circuit to realize compensating current reverse, a magnetic core of the magnetic probe winding quits a saturated state when tested current recovers to a measuring range, a current measuring function is recovered, and the zero-flux current sensor recovers to a normal operating state.

Zero-flux current sensor

The invention discloses a lead potential measurement method. The lead potential measurement method is characterized in that a first three-dimensional electric field sensor and a second three-dimensional electric field sensor are disposed in advance in a preset range around a to-be-tested lead, that lines where the two-dimensional electric field sensors are located are not parallel to the to-be-tested lead is guaranteed, and a potential value of the to-be-tested lead is calculated based on the first electric field intensity measured by the first three-dimensional electric field sensor, the position information of the first three-dimensional electric field sensor, the second electric field intensity measured by the second three-dimensional electric field sensor and the position information of the second three-dimensional electric field sensor. The method is advantaged in that the two three-dimensional electric field sensors are utilized, compared with a voltage transformer, a measurementdevice is lighter, access with a tested line is not needed, influence of the tested line is reduced to the maximum degree, compared with one electric field sensor, requirements for the test positionare greatly reduced, measurement difficulty is reduced through utilizing two angles, and measurement accuracy is improved. The invention further provides a lead potential measurement device and system. The advantages are further achieved.

Lead potential measurement method, device and system

The invention discloses a wide-frequency-range transient space electric field measuring system and method. The system comprises a dual-plate electrode sensor, a front-end signal processing unit, a signal collecting recording unit and a transmission unit; the dual-plate electrode sensor is arranged in a transient space electric field for sensing, transient space electric field signals are convertedinto measurable voltage signals; the front-end signal processing unit is used for processing and controlling the measurable voltage signals input by the sensor and optimizing waveforms of the outputvoltage signals; the signal collecting recording unit is used for collecting and recording voltage signals output by the front-end signal processing unit, and obtaining transient electric field signals through calculation of the collected voltage signals; the transmission unit is used for transmitting the voltage signals converted by the front-end signal processing unit to the signal collecting recording unit to achieve remote measurement; according to the system and method, the differential operation function does not need to be enabled, and therefore the lower limit of the measurable electric field frequency is widened.

Wide-frequency-range transient space electric field measuring system and method

The invention relates to an automatic test bench system for a wireless charging system of an electric vehicle. The system comprises the following parts: an upper platform, used for placing a wirelessly charged receiving coil; a lower platform, used for placing a wirelessly charged transmitting coil; a movable base, provided with an XYZ-axis servo motor, wherein the XYZ-axis servo motor is connected with the lower platform to drive the lower platform to move synchronously so as to realize the gap offset between the upper platform and the lower platform; a power analyzer, used for testing real-time powers of the receiving coil and the transmitting coil; a host computer, connected to the power analyzer; and a controller, connected to the host computer and the XYZ-axis servo motor respectivelyand used for controlling the action of the XYZ-axis servo motor according to a command of the host computer. Compared with the prior art, the automatic test bench system for a wireless charging system of an electric vehicle changes the position of the lower platform through the driving the of servo motor to change the offset distance between the upper and lower platforms in the horizontal XY direction and the vertical Z direction so as to study the change situation of the wireless charging transmission power and efficiency under different dislocations, thereby greatly improving the test efficiency and test accuracy.

Automatic test bench system for wireless charging system of electric vehicle

The invention relates to a direct-current combined field intensity and ion current density synchronization measurement system based on wireless communication. The system comprises at least 10 direct-current combined field intensity probes, 10 ion current density probes, one upper computer and one PC terminal. A built-in lithium battery is used to provide power for the direct-current combined field intensity probes, the ion current density probes and the upper computer so that long-time field measurement can be achieved. Each direct-current combined field intensity probe and each ion current density probe are communicated with the upper computer through using a wireless communication module. The upper computer and the PC terminal are connected through a USB connecting line. Measurement arrangement and a measuring point position can be conveniently adjusted so that operating efficiency is greatly increased and labor intensity is reduced. The system supports multiple devices, synchronously measures direct-current combined field intensity and ion current density in a high precision mode and really reflects a level and distribution of the direct-current combined field intensity and the ion current density so that an important basis is provided for extra/ultra-high-voltage direct current transmission project electromagnetic environment monitoring, evaluation and influence research.

Direct-current combined field intensity and ion current density synchronization measurement system based on wireless communication

The invention relates to a method for getting rid of radio jamming field measurement abnormal values. The method comprises a step (1) of obtaining a histogram of radio data and a distribution pattern of the histogram; a step (2) of preliminarily determining whether the radio data belongs to normal distribution according to the distribution pattern of the histogram; if the radio data belongs to normal distribution, executing a step (3), or else executing a step (5); the step (3) of adopting a single sample K-S inspection method to determine whether the radio data belongs to normal distribution; if the radio data belongs to normal distribution, executing a step (4), or else executing the step (5); the step (4) of adopting a Robust-Z inspection method to get rid of abnormal data of the radio data; and a step (5) of getting rid of the abnormal data of the radio data based on a normalization processing bounded beta(g,h) distribution function method. The pure statistical method is utilized to get rid of abnormal data values, and a more accurate radio jamming value generated by an electric transmission line can be obtained.

Method for getting rid of radio jamming field measurement abnormal values

The invention provides a paralleling-reactor sound-shield sound reduction measuring method and device. The method includes: measuring first sound intensity level located at the first default distance of a paralleling reactor and calculating sound power level of the paralleling reactor according to the measured first sound intensity level; mounting a sound shield on the paralleling reactor, measuring second sound intensity level at the first default distance of the sound shield and calculating sound power level according to the measured second sound intensity level; determining difference value of the calculated sound power level of the paralleling reactor and the sound power level of the sound shield to be sound reduction of the paralleling-reactor sound shield. The sound reduction is calculated through measurement of the sound intensity levels, sound intensity which is a vector and has directionality is less prone to interference of outer environment, the measured sound intensity is more accurate and reliable, and accuracy in calculation of the sound reduction is improved.

Paralleling-reactor sound-shield sound reduction measuring method and device

The invention relates to a method and system for determining an environment protection information transmission effect of a grid. The method comprises: an evaluation index system of an environment protection information transmission effect of a grid is established; a hierarchical structure graph of a transmission effect is constructed; a value of an importance degree of an influence on an environment protection information propagation effect of the grid by each first-order index is determined; on the basis of the values, a determination matrix A is established; a maximum feature value and a maximum feature vector of the matrix A are calculated and consistency checking is carried out on the determination matrix A; when the determination matrix passes the consistency checking, a grid environment protection information transmission effect evaluation formula is established based on the maximum feature value of the determination matrix and the corresponding feature vector, wherein the formula is as follows: an information transmission effect=omega01*(attention rate)+omega02*(interest rate)+omega03*(query rate)+omega04*(action rate)+omega05*(haring rate)+omega06*(query-sharing rate); and on the basis of the evaluation rate, index assignment is carried out for an environment protection propagation activity plan of the power grid and a quantitative evaluation result of the information transmission effect is determined.

Ni Yuan

Papers

Direct-current combined field intensity and ion current density synchronization measurement system based on wireless communication

Method for getting rid of radio jamming field measurement abnormal values

Paralleling-reactor sound-shield sound reduction measuring method and device

Method and system for determining environment protection information transmission effect of grid

Wide-frequency-range transient space electric field measuring system and method