444 results about "Earthing system" patented technology

The invention provides a multi-dimensional electrical equipment insulation analysis and evaluation method, and relates to the technical field of electrical equipment insulation online detection and intelligent diagnosis. According to the method, an electrically isolated direct current detection channel is constructed in a neutral point small resistance grounding system, controllable direct current detection signals are injected, micro direct current leakage response signals are collected, and after zero drift correction, temperature compensation and power frequency ripple suppression are carried out, layered attribution is carried out in combination with primary system topology and an equipment ledger, and a multi-dimensional response matrix is formed. According to the method, environment and working condition normalization is realized through factor rejection and robust pull-back, a mechanism model containing leakage channel equivalent parameters and path constraints is established, multi-working-condition data is fused to calculate equivalent insulation parameters and credibility indication quantity, and a multi-dimensional insulation representation vector is generated. And performing time sequence analysis on the representation vector, extracting degradation and abrupt change characteristics, outputting a health index and a risk level, and realizing quantitative evaluation and intelligent early warning of the insulation state.

The invention particularly relates to a discharge machining simulation control system for a nuclear power plant in a high-radiation boron-containing water environment, which belongs to the technical field of special maintenance in the high-radiation environment of the nuclear power plant and comprises a man-machine interaction system, a discharge machining control system and subsystems. Each subsystem comprises a pulse power supply system, a servo power system, a washing system, a purification system, a grounding system and a tool system; the man-machine interaction system is used for man-machine interaction and displaying the discharge machining implementation data fed back by the subsystems; the electric discharge machining control system is used for generating an electric discharge machining instruction according to the man-machine interaction information and controlling the subsystems to cooperate to perform electric discharge machining work; and each subsystem is used for implementing electric discharge machining work according to the electric discharge machining instruction and feeding back electric discharge machining implementation data. According to the invention, simulation control of discharge processing in the high-radiation boron-containing water environment of the nuclear power plant is realized.

The invention discloses a power distribution network grounding fault research and judgment analysis method, relates to the technical field of power distribution network fault analysis, and solves the technical problem that fault analysis is not accurate and deep enough due to the fact that fault features in a neutral point grounding complex fault scene cannot be comprehensively considered. According to the method, single-phase grounding fault models of a neutral point ungrounded system, an arc suppression coil grounded system and a small resistor grounded system are respectively constructed, grounding current, phase voltage and neutral point voltage expressions under the models are detailedly deduced, and characteristics of voltage and current before and after a fault point in the steady-state and transient-state processes are deeply analyzed; the method comprehensively considers various complex fault scenes, can more accurately grasp essential characteristics of faults in different grounding modes, and provides a more comprehensive and accurate basis for fault diagnosis and processing.

The invention belongs to the field of single-phase earth fault line selection, and provides a small-current grounding system single-phase earth fault line selection method and system. The method comprises the following steps: acquiring fault current information of a small current grounding system; extracting fault features in the fault current information; the fault characteristics at least comprise a zero-sequence current amplitude, a zero-sequence current phase angle, a fifth harmonic current amplitude, a fifth harmonic current phase angle and a transient zero-sequence current amplitude; the extracted fault features are parallelly and correspondingly input to a first neural network model, and single-phase earth fault line selection initial results corresponding to the fault features are obtained; the number of parallel fault classifiers contained in the first neural network model is the same as the number of fault features; and inputting all the initial line selection results into the second neural network model to obtain a final single-phase earth fault line selection result.

The invention discloses a method for carrying out zero sequence loop impedance calculation by using a frequency conversion signal, the calculation method is applied to a power distribution network arc suppression coil grounding system, and the power distribution network arc suppression coil grounding system comprises a control device, a grounding transformer, an injection transformer and a variable signal source; according to the method, the signal source is adopted to inject signals with different frequencies to calculate the capacitive current, the impedance parameter of the arc suppression coil and the capacitive current of the system during parallel operation are calculated by establishing a loop equation according to different system zero sequence loop impedances under different frequencies, and then the capacitive current needing to be compensated by the system is accurately calculated. The method solves the problems of the calculation of the capacitance current of the system and the automatic tracking of the arc suppression coil during the parallel operation of the two machines, is not affected by the unbalance of the system, and provides a reliable basis for the precise control of the parallel operation of the two machines of the arc suppression coil.

A dynamo-electric rotary machine includes a rotor defining an axis, a stator, and a can designed for arrangement in an air gap between the rotor and the stator in order to seal the stator and the rotor in relation to each other. The can has at least one section of average electrical conductivity in a range from 1 S / m to 10000 S / m in an axial and / or a tangential direction. The can is electrically conductively incorporated in an earthing system of the dynamo-electric machine.

A method and system for measuring distribution network system parameters based on harmonic injection, for use in a low-current grounding system containing an arc suppression coil. The system injects currents of multiple frequencies into the neutral point of the low-current grounding system through an injection source and measures the neutral point voltage. The system uses formulas to calculate and obtain the line capacitance, arc suppression coil inductance, and damping resistance parameter values ​​in the distribution network system. This application can accurately measure line capacitance, arc suppression coil damping resistance, and reactance by injecting only two frequencies of current. This method has little impact on grid operation, high measurement accuracy, and broad application prospects.

The invention discloses a grounding fault judgment method and system of a distribution line grounding system, a storage medium, electronic equipment and a computer program product. According to the ground fault judgment method, the ground fault judgment system determines a zero-sequence voltage abrupt change value and a zero-sequence voltage amplitude according to the collected zero-sequence voltage of the distribution line; under the condition that the zero-sequence voltage abrupt change value meets a preset zero-sequence voltage abrupt change value condition, determining a transient grounding judgment result and a zero-sequence admittance value according to the collected zero-sequence current and zero-sequence voltage of the distribution line; determining the classification condition of the zero-sequence admittance value according to the transient grounding judgment result; under the condition that the zero-sequence voltage amplitude meets a preset zero-sequence voltage amplitude condition, determining a zero-sequence admittance judgment result according to the classification condition of the zero-sequence admittance value and the zero-sequence admittance value; determining a grounding comprehensive result according to the transient grounding judgment result and the zero-sequence admittance judgment result; and determining a grounding fault condition of the distribution line according to the grounding comprehensive result and a preset grounding result condition.

The invention discloses a construction method of an earth system coupling device and the earth system coupling device, and the construction method comprises the steps: a first component module construction step: constructing a plurality of first component modules of a global climate system based on full coupling, the plurality of first component modules comprise an atmospheric component module, a land component module, a sea ice component module, a ground ice component module, a river component module, a first ocean component module and a sea wave component module; a second component module construction step: constructing a second component module based on the ocean circulation simulation system, wherein the second component module is a second ocean component module; a replacement step: replacing the first ocean component module with the second ocean component module; and a coupling step: reconstructing a coupling application interface of the coupler of the global climate system based on full coupling, and carrying out data exchange and interaction among different component modules through the coupling application interface.

The invention discloses a full-power variable-speed pumped storage unit stator winding insulation state online monitoring method, and provides a high-capacity generator unit stator winding insulation state online monitoring method which can be applied to a network side transformer neutral point ungrounded system. According to the method, an effective common-mode monitoring loop can be established, and monitoring is carried out by utilizing the third harmonic of the motor stator winding and is not interfered by the high-frequency switch harmonic of the frequency converter. In order to solve the problem that a full-power variable-speed pumped storage unit generally has large capacity and is not easy to realize online measurement, the invention provides a method for measuring on a neutral point outgoing line, which can realize online measurement of the insulation state of a stator winding when the load current is relatively large. The method is suitable for a full-power variable-speed pumped storage high-capacity unit, leakage current measurement can be carried out under the condition of large load current, and stator insulation information online monitoring is achieved.

The utility model relates to the technical field of enterprise power grid operation and maintenance, in particular to a rapid isolation protection device for a grounding fault of a power grid neutral point ungrounded system, and aims to solve the problems that when the grounding fault of the power grid neutral point ungrounded system is processed at present, grounding is relieved by generally adopting an arc-extinguishing and resonance-eliminating mode of manually resetting a rapid switch; and a large-area power failure accident is caused by breakdown and short circuit of an insulation weak point of equipment in a system due to too long processing time. According to the device, a fault point is isolated through zero-sequence power direction protection action tripping, closing of the vacuum circuit breaker is converted into metal grounding through action of the quick switch arc-extinguishing and resonance-eliminating circuit, and quick fault isolation is effectively realized through automatic resetting and delay setting functions of the arc-extinguishing and resonance-eliminating circuit. Therefore, the repeated action of the rapid switch arc-extinguishing and resonance-eliminating circuit caused by intermittent arc grounding is avoided, the occurrence rate of large-area power failure accidents caused by arc grounding is greatly reduced, and the safe and stable operation of an enterprise power grid is further ensured.

The invention discloses a pile foundation external application device, a grounding pile foundation and a grounding system, the pile foundation external application device is cylindrical and comprises a base body layer, a transition layer and an external coating layer, the transition layer is wrapped by the external coating layer, the base body layer is wrapped by the transition layer, and the resistance of the transition layer is in index attenuation distribution from the resistivity of the base body layer to the resistivity of the external coating layer. Therefore, the substrate layer, the transition layer and the outer coating layer form a gradient conductive structure, the resistivity of the pile foundation external application device is in gradient distribution, the interface potential barrier is effectively inhibited, and the pile foundation grounding resistance is effectively reduced after the pile foundation external application device is externally applied to a grounding pile foundation, so that the grounding resistance of a grounding system is reduced, and the diversion performance of the grounding system is improved.

The invention provides a resonant grounding system high-resistance grounding fault phase selection method based on frequency domain energy change, and belongs to the field of medium-voltage power distribution network fault detection. The invention provides a phase selection method based on frequency domain energy change in order to solve the problems that high-resistance grounding fault phase selection is difficult and power grid parameters are unbalanced in a resonant grounding system. The method comprises the following steps: firstly, acquiring a three-phase voltage signal of a fault line, and filtering the signal through a 4-order Butterworth low-pass filter to eliminate high-frequency noise interference; analyzing frequency domain energy change of the three-phase voltage before and after the fault by using fast Fourier transform, and extracting fault features; and finally, constructing a novel phase selection criterion based on the positive and negative values of the three-phase voltage frequency domain energy change, the frequency domain energy change vector and the projection thereof, and realizing fault phase selection. According to the method, the fault phase and the non-fault phase can be effectively distinguished, the method is particularly suitable for accurate phase selection of the high-resistance grounding fault, and the reliability and the safety of medium-voltage power distribution network fault diagnosis can be remarkably improved.

The invention discloses a submarine cable interlayer fault detection method and system for a submarine cable grounding system, and a medium. The method comprises the following steps: S1, pre-installing a power frequency current sensor, a power frequency voltage sensor and a traveling wave sensor on a sheath layer and an armor layer of landing sections at two sides of the high-voltage alternating-current submarine cable grounding system; the method comprises the following steps: extracting current and voltage signal data of a fault state through a power frequency current sensor, a power frequency voltage sensor and a traveling wave sensor, and carrying out data preprocessing including detection cleaning, data interpolation and data normalization on the current and voltage signal data; according to the method, fault codes are obtained through data collection, preprocessing, feature fusion, training learning and coding reconstruction and classification, and accurate fault detection is carried out on submarine cable interlayer faults through the fault codes.

The invention discloses an open-phase detection method and device suitable for a system with multiple starting standby transformers. The method comprises the following steps: measuring a three-phase current on an incoming line, measuring a neutral point zero sequence voltage of each starting standby transformer, and collecting a neutral point grounding knife switch position of each starting standby transformer; based on the three-phase current on the incoming line, calculating an incoming line positive sequence current and an incoming line zero sequence current by using a symmetric component method; and according to the incoming line zero-sequence current, the neutral point zero-sequence voltage of each starting standby transformer and the position of a neutral point grounding knife switch, judging whether an open-phase fault occurs and positioning a fault interval. The method is suitable for a parallel connection mode of a plurality of starting and standby transformers, is also suitable for a transformer neutral point grounding or non-grounding system, and can effectively identify open-phase faults on a high-voltage side and a line of the starting and standby transformer under no-load and light-load working conditions.

The invention relates to the field of power systems, in particular to a power cable cross interconnection grounding system live-line maintenance method and system. The method comprises the following steps: firstly, synchronously acquiring cable line load current, three-phase grounding ring current and grounding resistance at the head end and the tail end of a metal sheath of a crossed interconnection unit with ring current abnormity, and generating a real-time data set with a timestamp; extracting cable structure parameters based on a preset cable topology database, and dynamically associating the cable structure parameters with the real-time data set; constructing a multi-conductor transmission line equation model, calculating a theoretical circulation distribution value of each section of sheath, and generating a theoretical circulation map; carrying out matching analysis on the theoretical circulation map and actually measured circulation data, and determining defect types and positions; and finally, according to a defect positioning result, the maintenance operation is executed in an electrified state through the insulating mechanical arm, and the stability of the grounding impedance of the system is maintained through the bypass grounding device. The problems that in the prior art, the live detection function is incomplete, and defects cannot be rapidly and accurately positioned are solved.

An enclosure to protect people and instruments from the effects of an electromagnetic pulse (EMP) is provided. The enclosure includes a floor assembly; walls extending upward on a first, second, third, and fourth side of the floor assembly; a roof; and a ceiling. On the interior of the enclosure, a shield layer is provided such that the enclosure forms a six-sided Faraday cage. Fasteners and other conductive securement materials such as copper tape help achieve the conductivity of the shield layer. Extending through the walls of the enclosure may be secure points of entry allowing for people, air, and conductors to securely enter and exit the enclosure. The enclosure contains a grounding system to assist with protecting the contents of the enclosure from the effects of the EMP.

The invention discloses a task collaborative unloading method and device for a space-air-ground integrated scene and a simulation system, and relates to the technical field of edge computing collaborative unloading. According to the task collaborative unloading method for the space-air-ground integrated scene, unloading of a target task is achieved through two stages; in the first stage, a matched execution end is selected according to task information of a target task; when the execution end is a satellite cluster end, second-stage unloading is carried out, and in the second-stage unloading, the matched execution satellite is selected to execute the target task according to the satellite information of the satellites. According to the method, the effectiveness of task collaborative unloading in a space-air-ground integrated system composed of the user side, the satellite cluster side and the cloud server side is improved.

The invention discloses a fault current calculation method and system for a high-voltage alternating-current submarine cable grounding system and a storage medium, and the method comprises the following steps: enabling a power supply device and an electric device to be equivalent to an impedance and series voltage source combination and a load impedance based on the Thevenin equivalence theorem; in combination with the double-end grounding characteristic, a submarine cable loop is equivalent according to a pi type, and a three-phase equivalent circuit is constructed; determining a fault phase, and dividing the submarine cable as a left side and a right side by a fault point; a voltage loop equation is listed based on the Kirchhoff theorem, and a matrix recursion rule is deduced in combination with a double-side elimination principle. And establishing an analytic relationship between the main sections of the submarine cables at the power side and the short-circuit side and the fault circulating current according to a recursion rule. And with a fault point current equation as a boundary condition, left sheath fault circulation distribution is solved simultaneously. And repeating the steps on the right side to obtain right side distribution so as to obtain fault phase whole-line distribution. According to the method, the circulation distribution can be accurately calculated, the fault analysis accuracy and efficiency are improved, and support is provided for submarine cable operation and maintenance and the like.

The invention discloses a grounding resistance thermal-electric coupling prediction method and system suitable for various soil scenes. The method comprises the following steps: acquiring an electrode parameter, a soil parameter, a grounding fault parameter and initial temperatures of an electrode and soil; calculating an electrode current and a soil leakage current of the time step based on the electrode and soil resistivity of the time step; based on the electrode current and the soil leakage current of the time step, calculating the electrode temperature, the soil radial temperature distribution and the grounding potential rise of the time step by adopting a finite difference method; based on the electrode temperature and soil radial temperature distribution of the time step, updating the electrode resistivity and the soil resistivity of the time step + 1; if the end of the fault time is not reached, returning to continuously calculate the temperature of the electrode and the soil at the time step + 1; otherwise, outputting the electrode temperature and soil radial temperature distribution of each time step. According to the invention, thermal-electric dynamic coupling is considered, and accurate evaluation of the performance of the grounding system is realized.

The invention belongs to the technical field of fire-fighting alarm system construction, and discloses a construction technology for a fire-fighting automatic alarm system, and the technology comprises the following steps: S1, cable laying and protection; s2, accurately positioning and installing the detector; s3, system grounding and electromagnetic protection; s4, dynamic parameter adjustment and linkage test; and S5, performing three-dimensional shape scanning and compensation correction. A stable charge release path is formed through an independent grounding system and a multi-level shielding technology, external electromagnetic interference is effectively isolated, and real-time performance and accuracy of fire alarm signal transmission are guaranteed. The spatial layout optimization of the detector is combined with a laser calibration mechanism, the influence of structural shielding and airflow disturbance on sensitivity is broken through, and millisecond-level capture and positioning of fire characteristic signals are realized. A dynamic parameter closed-loop control and multi-system linkage verification technology ensures the cooperative response efficiency of emergency equipment under extreme working conditions, and constructs a whole-process security closed loop from early warning to disposal.

The invention discloses a method and a system for diagnosing defects of a sheath grounding system under resonance voltage resistance of a power transmission cable. The method comprises the following steps: installing a sheath grounding current acquisition system; sequentially carrying out main insulation resonance voltage withstanding tests on three phases of the power transmission cable, and synchronously recording a grounding current waveform of a metal sheath by adopting a current acquisition system when each phase is subjected to voltage withstanding; processing the grounding current waveform by adopting a signal processing algorithm, and extracting a resonance component; and constructing a defect diagnosis matrix according to the resonance component, calculating a deviation between the defect diagnosis matrix and a standard matrix as a defect characterization value of the cable sheath grounding system, and obtaining a defect diagnosis conclusion of the sheath grounding system under the resonance withstand voltage of the power transmission cable. According to the method, the grounding current waveform of the metal sheath is synchronously acquired and analyzed in the main insulation resonance voltage withstand test of the three-phase cable, the resonance component is extracted, accurate identification of the defect is realized based on deviation calculation of the defect diagnosis matrix, and the detection sensitivity and the diagnosis reliability of the latent defect of the sheath grounding system before the cable is put into operation are improved.

The invention discloses a liquid oxygen rock breaking system and method, the system comprises an oxygenation system, a gas distribution system, a fracturing rock breaking pipe system, an excitation system and an electrostatic prevention and removal grounding system, a fracturing rock breaking pipe comprises a flexible outer sleeve film, an oxygenation guide pipe in the flexible outer sleeve film extends to the bottom and is filled with an adsorption combustion agent, and the top end of the flexible outer sleeve film is sealed through a hole sealing filling body. The method comprises the steps of manufacturing and installing the fracturing rock breaking pipe, sealing holes through the hole sealing filling body, laying the gas distribution pipeline and the wire, precisely injecting oxygen and synchronously exciting. Through modular integration and structural innovation, the problems that in a traditional liquid oxygen rock breaking technology, oxygenation is not uniform, pressure is unbalanced, excitation is not synchronous and the like are solved. The multi-stage gas distribution system is combined with the flow distributor to achieve dynamic distribution of liquid oxygen according to the drilling depth, the flexible outer sleeve film is matched with the hole sealing filling body to form a pressure self-balancing structure, a wire network is excited in parallel to guarantee millisecond-level synchronous ignition of multiple pipes, and static electricity prevention and removal grounding guarantees construction safety.

The utility model discloses a radio monitoring special vehicle lightning protection grounding device comprising a cabinet which is used for collecting system equipment in the cabinet to a grounding copper bar at the back of the cabinet; a plurality of grounding copper columns are arranged in the external interface box; wherein one grounding copper column is connected with the grounding copper bar; the other grounding copper columns are in grounding connection with the vehicle body; and the external grounding system is used for connecting the plurality of grounding copper columns with the ground. The lightning protection grounding device relates to a mounting structure for solving lightning protection measures in regions with frequent thunderstorms, so that the grounding resistance is greatly reduced, and the impact current can be effectively and quickly led into the ground. The problem of large grounding resistance is solved, and the problem of grounding of the vehicle body is also solved.

The invention relates to a method for identifying a single-phase earth fault of a power distribution network based on a phase current break variable characteristic, which comprises the following steps of: acquiring a three-phase current signal according to a set theoretical sampling frequency, calculating an effective value of the three-phase current signal, and completing three-phase current power-on judgment when specific conditions are met at the same time; carrying out frequency tracking sampling frequency real-time sampling monitoring on the zero-sequence current, extracting a zero-sequence current break variable difference current curve, and carrying out fault starting condition judgment on the difference current curve; extracting three-phase current fault component waveforms from a fault starting point, and then performing low-pass filtering processing on the waveforms to obtain effective frequency band characteristic waveforms and power frequency component characteristic waveforms; and calculating the fault characteristic quantity, and executing different single-phase grounding fault positioning algorithms according to different types of neutral point grounding systems. According to the method, the single-phase grounding fault of the power distribution network is identified by adopting the technical principle of definite physical rules through phase current and zero sequence current signals.

The invention discloses a single-phase grounding fault detection method and system for a small-current grounding system, and a storage medium. The method comprises the steps: obtaining the zero-sequence current and zero-sequence voltage of a to-be-detected line in a to-be-detected region; if the zero-sequence voltage of the to-be-detected line is greater than a starting value or the zero-sequence voltage break variable is greater than a set value, entering a single-phase earth fault detection step, otherwise, replacing one line in the to-be-detected area as the to-be-detected line, and repeating the above steps until entering the single-phase earth fault detection step; the single-phase earth fault detection step comprises the following steps of: preprocessing zero-sequence current and zero-sequence voltage of a line to be detected to obtain preprocessed image data; detecting the preprocessed image data by using a trained single-phase earth fault detection model to obtain a single-phase earth fault detection result; according to the invention, the accuracy and anti-interference capability of single-phase grounding fault detection in the small-current grounding system can be improved.

The invention discloses a high-voltage cable single-end grounding system resistor live-line detection method, which belongs to the technical field of high-voltage cable grounding system detection, and comprises the following steps: simultaneously arranging measurement clamps in a three-phase grounding loop of a high-voltage cable metal sheath; any two-phase grounding loop is selected as an injection loop, and a direct current constant current source is injected into the injection loop; measuring a direct-current voltage between the third-phase grounding loop which is not injected into the direct-current constant-current source after the multi-stage filtering processing and any phase injection loop by using a measuring clamp; and based on the current value injected into the direct current constant current source and the direct current voltage between the third-phase grounding loop and any phase injection loop, calculating the resistance value of the third-phase grounding loop which is not injected into the direct current constant current source. According to the method, the resistance value of each phase grounding loop can be accurately measured in the running state of the high-voltage cable.

The invention discloses a grounding resistance regular monitoring system and method, and belongs to the technical field of power equipment state monitoring. The system comprises a pulse generation module, a measurement module, a control module, a protection module and a communication module. The core lies in that a low-amplitude short-time-range direct-current pulse current is adopted to be injected into a grounding system, the pulse amplitude, width and frequency parameters are optimized to be always lower than the action threshold value of a relay protection device, and therefore accurate measurement is achieved on the premise that power is not cut off and misoperation is not caused. Meanwhile, historical data trend analysis and soil environment factors are fused, the deterioration trend of the grounding resistance is intelligently predicted, early warning is performed in advance, and a resistance reduction device can be linked for automatic adjustment. The method effectively solves the problems that a traditional measurement method needs power failure and is poor in interference resistance and an existing online monitoring technology is likely to trigger protection by mistake, and achieves safe, accurate, automatic and intelligent monitoring, operation and maintenance of the grounding resistance.

The present invention belongs to the technical field of fault detection in power systems, and proposes a line selection method for single-phase grounding faults in small current grounding systems, including collecting the fundamental component and the fifth harmonic component of the zero-sequence current of each line in the small current grounding system, and obtaining its inherent modal energy through empirical mode decomposition (EMD); then, these fault characteristics are used as input, BP neural network is used for fusion processing, and the line selection result is output. The line selection method for single-phase grounding faults in small current grounding systems proposed by the present invention has the advantages of high line selection accuracy, fast speed, good reliability, etc., and can be widely used in fault detection and positioning of power systems, providing a strong guarantee for the safe operation of power systems.

The invention relates to a grounding system and a power supply and distribution system, the grounding system comprises a bearing device and a grounding device, a bearing frame of the bearing device is used for bearing at least one electrical device, the grounding device comprises at least three grounding electrodes, and the grounding electrodes are sequentially connected to form a closed loop, a grounding conductor of the electrical equipment is connected to the bearing frame, or the grounding conductor is connected to the grounding device; according to the grounding system provided by the embodiment of the invention, the bearing frame is fully utilized as a fault current discharge channel and then is connected to the grounding device, or the grounding conductors of the electrical equipment are uniformly connected to the grounding device, so that grounding protection of the electrical equipment is realized, and the wiring complexity is reduced while the cost is reduced.