2228 results about "Voltage variation" patented technology

The invention provides a power grid multi-agent large model safety evaluation index calculation method, and relates to the technical field of intelligent control. The method comprises the following steps: acquiring a voltage change rate and a frequency change rate, dividing four stages according to disturbance starting and extreme points, pairing curve trends, judging delay and synchronization characteristics, extracting a continuous change structure, and generating a disturbance subsection evolution structure; according to the method, through staged analysis of node voltage and frequency change trends and combination of trend consistency judgment and abnormal segment identification, dynamic structure reconstruction and trend mapping of a disturbance process are realized, and coherence and precision of index response state identification are improved through trend boundary collection and frequency classification; cooperative characteristic identification is enhanced through the coupling direction and delay analysis of inter-node multi-parameter change, the node adjustment priority is defined through regulation and control response sorting, an adjustment path under multi-dimensional linkage is constructed, and the refined management and control capacity of disturbance response and the pertinence of control decision are improved.

The invention discloses an efficient and high-precision compensation system and method of an intelligent mutual inductor, and particularly relates to the technical field of mutual inductors. The method comprises the following steps: acquiring magnetic flux density and magnetic field intensity data of a mutual inductor under different current and voltage change rates, generating a hysteresis loop diagram, extracting hysteresis loop width, residual magnetism and coercive force characteristics, and establishing a hysteresis effect error model; the harmonic distortion is identified in combination with spectrum analysis, the harmonic distortion degree in a high-frequency environment is predicted, the hysteresis of the hysteresis effect and the harmonic distortion are comprehensively analyzed, and the accuracy of a compensation algorithm for processing nonlinear errors is evaluated; and finally, the compensation signals are divided into high-accuracy signals and low-accuracy signals, the high-accuracy signals are directly output, and the low-accuracy signals are output after error correction, so that the problem that a conventional compensation algorithm cannot correct non-linear errors is effectively solved, and the measurement precision of the mutual inductor in an extreme environment and the operation stability of a system are improved.

A method and system for analyzing fault data features of an active distribution network. The method comprises: analyzing a voltage variation after a fault in an active distribution network and analyzing a single-phase ground fault (S1); acquiring distribution network fault data by means of analog simulation (S2); and establishing a fault location prediction model to analyze fault data features and realize fault localization (S3). In the method, a voltage variation after a fault in an active distribution network is analyzed, the voltage variation is equivalently represented using an injected current, a single-phase ground fault is analyzed, and the localization of a fault point is realized. By simulating a current variation during an actual fault injection process by means of an injected current function, a model can more closely reflect an actual operating state, thereby enhancing the authenticity of fault simulation and the accuracy of prediction. A complex relationship between a current variation and node impedance is deeply analyzed by means of a complex information filtering function, and more refined fault features are extracted, thereby optimizing the precision of fault localization, and enhancing the adaptability of the model to different fault scenarios.

The invention relates to the technical field of charging piles, and provides a DC charging pile voltage stability optimization method and device and a storage medium, and the method comprises the steps: obtaining voltage sequence data of a DC output end of a charging pile, carrying out the segmentation statistics of the voltage sequence data, and obtaining an optimization adjustment matrix and a voltage compensation factor matrix; and performing dynamic adjustment on a preset direct current output control strategy of the charging pile based on the optimization adjustment matrix to obtain an adjusted control strategy parameter, performing compensation calculation on the adjusted control strategy parameter by using the voltage compensation factor matrix to obtain an optimization control instruction, and generating a dynamic voltage stabilization control signal according to the optimization control instruction. An output control strategy is dynamically adjusted by optimizing an adjustment matrix and a voltage compensation factor matrix, an efficient dynamic voltage stabilization control signal is generated, and the problems of response lag and insufficient prediction precision existing in the prior art when a complex voltage fluctuation mode is processed and a future voltage change trend is predicted are solved.

The invention relates to the technical field of battery detection, in particular to a new energy vehicle battery fault intelligent detection system which comprises a voltage change analysis module, an internal resistance micro-analysis module, a current response monitoring module and a fault diagnosis integration module. According to the invention, by refining voltage monitoring and internal resistance analysis, the capability of early recognition of battery performance degradation and faults is remarkably improved, the early warning of the faults is more accurate by recognizing abnormities through an advanced data processing technology and refining fluctuation analysis, the risk of false alarm and missing alarm is reduced, and the internal resistance data is analyzed by introducing a fractal theory. Microscopic changes of battery aging can be more accurately captured, early detection of the aging trend is realized, pulse current testing and current response data analysis are combined, evaluation of battery performance stability is further enhanced, comprehensiveness and depth of a detection result are ensured, and detection accuracy is improved. And the accuracy of battery fault detection and the efficiency of determining the fault type are greatly improved.

The invention relates to the technical field of resistance measurement, in particular to a constructional engineering electrical grounding resistance detection system which comprises a path monitoring module, a delay judgment module, a path switching module, an interval regulation and control module and a data correction module. According to the method, the voltage stability is judged by collecting the path node voltage change value and the timestamp and calculating the voltage difference, precision screening is completed in cooperation with path state information, the abnormal fluctuation recognition capability is improved, the delay value change trend is combined with a period difference value comparison mode, and path stability evaluation is assisted; the path switching behavior is combined with feedback response and relay state recognition, the accuracy of channel switching is improved, the sampling interval is dynamically regulated and controlled according to delay change, clearer response characteristics are obtained in combination with waveform displacement mapping operation, the accuracy of data alignment is enhanced, and the accuracy of channel switching is improved. The whole process realizes a closed-loop processing structure of path identification, delay judgment, switching confirmation and waveform correction, and effectively improves the response consistency and time precision of ground resistance measurement.

The invention discloses an energy storage system state evolution trend prediction method based on multi-source data fusion. The method comprises the steps of terminal voltage, current and temperature time sequence data acquisition, time sequence segmentation normalization, multi-physics field coupling feature construction, trend prediction model construction and training and energy storage system state evolution trend prediction. According to the method, the distinguishing capacity of the model for charging and discharging physical characteristics is improved, meanwhile, the voltage change rate, the multi-dimensional feature vector of the differential internal resistance and the thermal-electric coupling effect and the explicit encoding electric-thermal-resistance coupling relation are constructed, the transient response and the temperature hysteresis effect can be effectively captured, and then the model can be used for analyzing the charging and discharging physical characteristics. A degradation-aware cross-cycle feature extraction and gating mechanism is adopted, short-term fluctuation and long-term trend are adaptively balanced in multi-scale prediction, the prediction conflict problem is relieved, finally, physical constraints based on the electrochemical law and the internal resistance temperature characteristic are embedded in a loss function, it is ensured that the prediction result is accurate in numerical value and conforms to the physical law, and the prediction accuracy is improved. And generation of physically impossible solutions is avoided.

The invention discloses a multi-end line pilot protection method and system based on time domain model identification, and relates to the technical field of electrical engineering, and the method comprises the steps: obtaining a three-phase voltage sampling value, a three-phase current sampling value and a switching value of each end of a multi-end line; judging whether each end of the multi-end line meets a protection starting condition or not; if yes, differential voltage variation and differential current are calculated, and correlation coefficients of the differential voltage variation and the differential current are calculated; judging whether the correlation coefficient is within a preset fault threshold range or not; if the correlation coefficient is not within the preset fault threshold range, determining that the multi-terminal line has an external fault, and enabling the protection device not to act; and if the correlation coefficient is within a preset fault threshold range, determining that the multi-terminal line has an internal fault, and enabling the protection device to act to remove the fault. According to the invention, the influence of capacitive current and a power electronic power supply on pilot protection performance is overcome, the operating characteristics of a relay protection device are improved, and safe and stable operation of a power system is ensured.

The invention relates to the technical field of voltage control, in particular to a time-delay-containing uncertain AC / DC micro-grid DC bus voltage control method, which comprises the following steps: acquiring load change and DC bus voltage fluctuation data, calculating a load current change rate, analyzing the correlation between voltage fluctuation and load change, and performing voltage adjustment. And time delay characteristics in a load state are identified, voltage fluctuation uncertainty factors are identified, and the time delay compensation amount is adjusted to restore the voltage stability. According to the invention, by adopting linear and nonlinear time-delay compensation strategies, the problem of accuracy of time-delay compensation under different load conditions is effectively solved, various load fluctuations and voltage changes can be dynamically adapted, the problem of uncertainty of voltage fluctuations is solved, and the prediction of voltage fluctuations is optimized by dynamically adjusting the weight of uncertainty factors. The over-reaction to sudden voltage change is reduced, the voltage stability is improved, and the operation stability and the voltage regulation precision of the micro-grid are remarkably improved.

The invention relates to the technical field of power system short circuit detection, and discloses a short circuit parameter measurement algorithm development method and system, and the method comprises the steps: carrying out the short circuit parameter measurement background analysis, and collecting a non-fault disturbance signal; non-fault disturbance signals are preprocessed, and key features are extracted; and establishing a short-circuit parameter prediction algorithm model, and performing classified early warning according to a prediction result. According to the invention, the reliability of short-circuit parameter prediction is improved. The response speed and accuracy to current and voltage changes are improved, and the problems of delay and false alarm in a traditional method can be effectively avoided. The model can retain key features when processing multi-source signals, and the accuracy and robustness of short-circuit parameter prediction are improved. According to the invention, accurate measurement of short-circuit current and voltage is realized, rapid identification and response can be ensured when a fault occurs in a power system, the fault recovery time of the system is reduced, and the safety and reliability of power grid operation are improved.

A capacitor-less linear Low Drop Out (LDO) Voltage Regulating (VR) system and method with enhanced Power Supply Rejection (PSR), line transient response, and load transient response is disclosed. The system includes a current-summing amplifier to refine input voltage and error signals from an error amplifier circuit, improving regulation accuracy. Further, the system includes a Dynamic Current Bleeder (DCB) circuit to manage current flow, optimizing efficiency. Furthermore, a strategically placed compensation capacitor ensures stable voltage delivery despite load or input changes. To further enhance performance, a boost and reduce amplifier circuit continuously monitors and adjusts current of the error amplifier circuit, minimizing output voltage variations. The system effectively manages applications demanding highly regulated and stable voltage supplies.

The invention relates to the technical field of battery monitoring, in particular to a method and system for evaluating the service life of a battery, and the method comprises the following steps: obtaining a voltage change sequence, analyzing a sudden change fallback period, extending and tracking a voltage and temperature path pairing trend, recognizing a direction sudden change node, and extracting internal resistance response abnormity; and screening a repetition period and comparing a multi-parameter change sequence to obtain a life state evaluation result. According to the method, abnormal nodes in voltage changes are extracted in a structured mode, a life fluctuation section is delimited by combining the deviation relation between the voltage and the temperature trend, temperature path direction changes are extended to recognize periodic abrupt change points, jump and trend fracture characteristics in internal resistance response are tracked, and time sequence correlation among various types of parameters is established; a periodic sequence covering the voltage, temperature and internal resistance change process is formed, the recognition capacity of the life fluctuation stage under the multi-parameter interaction background is enhanced, and linkage analysis and periodic positioning of key degradation characteristics in variable working conditions are supported.

The invention discloses a power-on reset circuit, and relates to the technical field of integrated circuits, in order to eliminate static power consumption of the power-on reset circuit and reduce power consumption of the power-on reset circuit, the power-on reset circuit comprises a discharge delay circuit, a current mirror circuit and a buffer circuit; the discharge delay circuit comprises a capacitor and an NMOS (N-channel Metal Oxide Semiconductor) tube M4, and the NMOS tube M4 is used for discharging the capacitor; the current mirror image circuit comprises an NMOS tube M2, an NMOS tube M3 and a PMOS tube M9. The grid electrode of the NMOS tube M2 and the grid electrode of the PMOS tube M9 are respectively connected with the output end of the buffer circuit; the grid electrode of the NMOS tube M3 is respectively connected with the source electrode of the PMOS tube M9, the drain electrode of the NMOS tube M2 and the grid electrode of the NMOS tube M4; the current mirror image circuit is used for turning off the NMOS tube M2 after the reset signal is ended, and pulling up the drain electrode voltage of the NMOS tube M3 to the power supply voltage through the PMOS tube M9, so that the NMOS tube M3 enters a deep linear region, and a direct current path from the power supply to the ground in the current mirror image circuit is cut off; and the buffer circuit is used for outputting a reset signal according to the voltage change of the capacitor in the discharge delay circuit.

The invention relates to the technical field of performance testing, in particular to an electrochemical performance testing system and method for an energy storage device, and the system comprises a time synchronization triggering module, an impedance track acquisition module, a degradation state recognition module, an electrochemical abnormity monitoring module and a performance testing judgment module. According to the invention, multi-channel concurrent synchronous acquisition of voltage, current, impedance and temperature is realized by calculating sampling delay compensation time, and lithium precipitation, micro short circuit and electrode interface damage trend can be accurately identified by calculating a gradient absolute difference sequence of a voltage change rate and a current change rate and linking an impedance abrupt change rate and short-period abnormal fluctuation. In the process of judging the state of the energy storage device, open-circuit voltage distribution, charging and discharging current stability and impedance change trend are considered in a combined manner, the recognition accuracy of an active state, a degradation state and an abnormal state is improved, and the precision and reliability of electrochemical performance testing are improved.

The invention discloses a single-stage bidirectional power conversion topological structure capable of realizing wide-range soft switching and a control method of the single-stage bidirectional power conversion topological structure. In-bridge and inter-bridge phase shift control of a double-half-bridge circuit and a high-frequency switch matrix provides a basis for realizing soft switching of all power tubes; the switching frequency is adjusted in real time according to the magnitude of the port voltage, soft switching within a wide voltage change range is achieved, the current of a bridge arm connected with the primary side of the second transformer is the sum of the primary side current of the second transformer and the current of an inductor connected in parallel with the second transformer, and the inductance value of the inductor connected in parallel with the primary side of the second transformer is designed. The current of the bridge arm connected with the primary side of the second transformer can be effectively changed, so that the soft switching implementation range of the switching tube of the bridge arm connected with the primary side of the second transformer in a wide power transmission range can be expanded.

The invention provides a training method applied to construction of an AI basis of a power system, and the method comprises the steps: obtaining voltage data in the power system, and converting the voltage data into a digital signal through high-frequency sampling and adaptive quantization processing, thereby constructing a voltage time sequence data set containing harmonic content, voltage change amplitude and frequency characteristics; inputting the established flicker detection model of the power equipment into historical data of a large-scale power system for pre-training, and performing fine adjustment on the pre-trained model by using a small amount of labeled data, so that the model can adapt to a specific scene in which flicker is caused by a transformer and a generator due to voltage fluctuation; on the basis of model distillation, a model cutting method is used and comprises structured sparse cutting, filter cutting and compression of parameter quantity and calculation complexity of a model, and by setting a sparsity threshold, neurons and connections which are crucial to tasks are reserved, and redundant structures are reduced.

The invention belongs to the technical field of power system power distribution network relay protection, and provides an active fault property discrimination method based on injection disturbance current response characteristics, which comprises the following steps: step 1, when an inter-phase fault occurs in a system, three-phase tripping of a fault line outlet circuit breaker occurs, and according to three-phase current and voltage change conditions before and after the fault, determining whether the fault occurs or not; determining two phases with increased line current and reduced voltage as fault phases; 2, delaying for 200ms after the circuit breaker trips, and controlling the action of a split-phase switch; according to the method, disturbance current signals are injected through an external power supply, the disturbance signals have obvious difference in response characteristics during permanent faults and instantaneous faults, the reliability and superiority of the method under different working conditions are verified through simulation, the method makes up for the defects of an active injection type method during fault property recognition processing, and the method has the advantages of high reliability and high reliability. The method is not influenced by injection time and fault duration, fault property discrimination can be realized only through one-time injection, and the method is simple in operation, small in calculation amount and high in reliability.

The invention discloses an arc fault detection method and device based on voltage time difference variation, and belongs to the technical field of low-voltage power distribution network fault protection, and the method comprises the steps: enabling an arc fault point to be equivalent to an arc voltage source, and employing an arc voltage change rate and an arc voltage effective value, establishing detection feature description of a fault waveform generated by the arc voltage source, wherein the fault waveform presents a square-wave-like waveform; sampling adjacent cyclic wave voltages of a load side monitoring point, performing feature identification on the tail end voltage difference between adjacent cyclic waves based on detection features, and identifying a first fault waveform; and after the first fault waveform occurs, performing continuous identification counting on the arc faults, realizing identification of the continuous arc faults by using the difference between the non-fault waveform before the fault occurs and the waveform to be identified, and confirming the occurrence of the arc faults. The detection method is good in reliability, clear in physical significance, high in detection sensitivity, not affected by line parameters, capable of achieving detection only through a single monitoring point and lower in cost.

The invention relates to the technical field of power supply equipment power control. The load power track simulation control method comprises the steps of obtaining voltage information and current information of target power supply equipment, determining power deviation information and a dynamic target voltage range generated on the basis of a preset load behavior prediction model, constructing a combined regulation and control weight vector on the basis of the power deviation information, and obtaining a load power track simulation control result. According to the combined regulation and control weight vector and the dynamic target voltage range, constructing a target power evolution trajectory curve by using a physical response inversion mechanism, executing time discretization processing on the target regulation and control trajectory curve, extracting voltage change values and current change values corresponding to each time step, and calculating the target power evolution trajectory curve; and combining the voltage change value and the current change value according to a time sequence to form a control parameter sequence, and generating an analog control instruction matched with the target power evolution trajectory curve according to the control parameter sequence. The method has the effect of improving the real-time response capability of the power supply equipment under complex working conditions.

The invention discloses a power grid node frequency intensity and voltage intensity-oriented quantification method. The method comprises the following steps of: 1) respectively considering an inertia evaluation strategy of equivalent inertia of a synchronous machine, equivalent inertia of a new energy converter station and equivalent inertia of a load to be used for analyzing node-level inertia support intensity of a system; 2) proposing a power grid node level frequency intensity quantification strategy based on power grid node frequency deviation, frequency change rate and node inertia intensity; and 3) a system node voltage support strength quantification method considering node short-circuit capacity influence caused by voltage drop. And 4) proposing a power grid node-level voltage intensity quantification strategy considering the system node voltage deviation, the voltage change rate and the operation short-circuit ratio. According to the invention, through frequency voltage disturbance quantity information, inertia intensity and a short-circuit ratio, influences of different response characteristics of different inertia sources and system operation state changes on the short-circuit ratio are considered, and frequency support intensity and voltage support intensity are respectively subjected to quantitative analysis; the accuracy and reliability of frequency support strength and voltage support strength quantification are improved.

The invention relates to the technical field of energy storage converter control, and discloses a dynamic voltage regulation and control method and system for an energy storage converter, and the system comprises a data collection module and an evaluation management module. According to the system, voltage change data and current change data are acquired through a data acquisition module and classified to form a data set, and an intelligent management module sets a monitoring period, analyzes the change trend of each phase voltage instantaneous value, generates a corresponding fluctuation data set, quickly locates a problem source, monitors the waveform of each phase voltage amplitude in real time, and generates corresponding monitoring data. The energy storage converter can adapt to power grid systems or energy storage devices of different scales, the intelligent management module analyzes deviation loss of electric energy in each conversion process and accurately evaluates the energy conversion efficiency of the energy storage converter in a rectification / inversion mode, the integration evaluation accuracy is high, the intelligent management module judges the power grid electric energy quality and harmonic distortion problems, and the energy conversion efficiency of the energy storage converter in a rectification / inversion mode is improved. And corresponding regulation and control suggestions are output, and the dynamic regulation and control response speed is high.

The invention discloses a battery pack abnormal monomer detection method and system based on a local outlier factor algorithm. The method comprises the following steps: sampling and collecting voltage data and current data of each battery monomer in a battery pack by adopting a sliding window method to obtain a monomer voltage matrix; respectively obtaining a first voltage characteristic F1 and a second voltage characteristic F2 according to the monomer voltage matrix U; calculating a voltage change consistency feature F3 of each cell in the sliding window according to the cell voltage matrix U and the current data of the cell; integrating the first voltage feature F1, the second voltage feature F2 and the voltage change consistency feature F3 into feature points, and integrating and mapping the feature points into data points; and performing anomaly detection on the data point set by adopting a local outlier factor (LOF) algorithm to obtain an abnormal data point which is an abnormal single battery in the battery pack. According to the invention, the accuracy of the abnormal cells in the battery pack can be improved, and the abnormal condition type can be judged.

The present disclosure provides a receiver front-end circuit including: first and second input units that alternately operate according to a common mode voltage of a differential input signal and output a differential output signal; a variable resistance unit that adjusts a differential load resistance supplied to the differential output signal according to the variable resistance control signal; and a control unit generating a variable resistance control signal according to a common mode voltage of the differential input signal. According to the receiver front-end circuit disclosed by the invention, the receiving of the differential input signal with a wider common-mode voltage range can be realized under low power supply voltage, and the output amplitude of the generated differential output signal does not change greatly along with the change of the common-mode voltage of the differential input signal; therefore, the compatibility of the receiver is improved, and the power consumption is reduced.

The invention relates to an early warning method and system for a turn-to-turn short circuit fault of a distribution transformer winding, and the method comprises the steps: obtaining the current, voltage, oil temperature, oil pressure and oil level of the distribution transformer winding, and calculating the maximum value of the dynamic power loss change rate, the maximum value of the voltage change rate and the maximum value of the main current change rate during the operation of the winding; when the oil pressure and the oil level are within a set range, and the maximum voltage change rate and the main current change rate are smaller than set threshold values respectively, corresponding signals are sent out according to the oil temperature and winding loss change conditions. The current, the voltage, the oil temperature, the oil level and the oil pressure obtained from the distribution transformer winding are utilized, the current change rate, the voltage change rate and the power loss change rate obtained through calculation are combined, multiple parameters are comprehensively considered, and the condition of the winding turn-to-turn short circuit fault is early warned. Compared with the prior art that only current change and power loss are considered, the method can more accurately perform early warning on the possible winding turn-to-turn short circuit fault.

The invention belongs to the technical field of radio frequency power supply detection, and discloses a radio frequency power supply arc rapid detection method and system, and the method comprises the steps: obtaining a voltage signal and a current signal after a coupler couples an output radio frequency signal; sampling the voltage signal and the current signal, performing digital signal processing, and calculating amplitude values of the voltage signal and the current signal; selecting a plurality of sampling points, and respectively calculating a voltage change rate and a current change rate; and the voltage change rate and the current change rate are compared with the threshold of the rated value to complete arc judgment. The FPGA is used as a main control chip, a sampling chip is a high-speed AD, the advantage of high real-time performance is achieved, whether the arc phenomenon occurs or not is judged by judging the change rate of the voltage and the current, and therefore the problem that threshold values of the voltage and the current are difficult to select can be avoided. The method has the advantages of short calculation delay, quick response and high judgment accuracy, and can obtain a judgment result in an extremely short time.

The invention discloses a regulation and control method and device for a load power supply loop, equipment, a medium and a program product, and relates to the technical field of servers, and the method comprises the steps: obtaining the current change rate, the contact temperature rise rate and the voltage change rate of a load interface when a hot plug event occurs, so as to comprehensively reflect the rapid change condition of a circuit state at the hot plug moment; then, inputting the data into a surge probability prediction model to obtain a surge occurrence probability so as to pre-judge a surge risk in advance; and when the surge occurrence probability is greater than or equal to a first preset probability, the resistance-capacitance parameters of the load power supply loop are calculated according to the monitored load interface current, load interface voltage and load interface temperature, so that when a hot plug event occurs, the circuit can be rapidly adjusted according to the resistance-capacitance parameters, abnormal changes of the current and the voltage are inhibited in time, and the reliability of the hot plug event is improved. The protection response speed is improved, equipment damage caused by untimely protection is effectively avoided, and the server is ensured to stably operate under complex conditions such as load hot plug.

The present application relates to an internal resistance determination method, an apparatus, a computer device and a storage medium. The method comprises: acquiring a plurality of sets of sampling data of a cell in a battery under test; on the basis of the plurality of sets of sampling data, determining a plurality of initial data variations; then performing fitting on the initial data variations, so as to obtain voltage fitting values corresponding to current variations among the initial data variations; on the basis of voltage variations and the voltage fitting values corresponding to the current variations among the initial data variations, performing screening on the initial data variations, so as to obtain a target data variation; and, on the basis of the target data variation, determining the internal resistance of the cell, wherein each set of sampling data comprises sampling data at two moments, and the initial data variations comprise the current variations and the voltage variations. The present method can be used to reduce the dependence on the battery status.

The invention discloses a power grid multi-agent collaborative large model security monitoring method and system, and relates to the technical field of smart power grid security monitoring. The method comprises the following steps: acquiring a voltage record of a node on a power grid multi-agent management path, delay time of load change and current direction change times, identifying a voltage change trend according to a node voltage valley value in a detection period, detecting whether the current direction is continuously reversed between two time periods, and obtaining a path list with consistent direction. According to the method, by comparing the relevance between the voltage and the load change time and the continuous reversal of the current direction, the stability problem and potential faults in the power grid can be effectively identified, large-scale faults are prevented in advance, resources can be more accurately adjusted by marking key abnormal sources and adjusting the path influence weight, and the operation efficiency of the power grid is optimized. The control capability on the overall safety and efficiency of the power grid is obviously improved, and the operation risk and maintenance cost are reduced.

A novel power storage system is provided. The power storage system includes a secondary battery and a subtractor. The subtractor includes a register. The subtractor has a function of converting a first voltage of the secondary battery into first voltage data by analog-digital conversion. The subtractor has a function of measuring time required for the first voltage to change only by a first voltage value. The register has a function of storing second voltage data that is higher than the first voltage data by a data value corresponding to the first voltage value. The subtractor has a function of stopping supply of power to the register until the first voltage changes by the first voltage value.

The invention provides a capacitance value detection method and device for a capacitor in an inverter, and belongs to the field of inverters. The method comprises the following steps: based on pre-stored voltage change rate information of a to-be-measured capacitor, determining voltage recording moments when the current of the to-be-measured capacitor is zero, the voltage recording moments at least comprising a first moment and a second moment; obtaining a first voltage value of the to-be-measured capacitor at the first moment and a second voltage value of the to-be-measured capacitor at the second moment, and obtaining an accumulated charge quantity of the direct current bus for charging and discharging the to-be-measured capacitor in a time period corresponding to the first moment and the second moment; and finally, determining the capacitance value of the capacitor to be measured according to the first voltage value, the second voltage value and the accumulated charge quantity. According to the method, the inverter does not need to be shut down, the capacitor does not need to be detached and measured, the capacitance value of the capacitor is calculated according to the voltage value when the current of the capacitor is zero, the influence of ESR can be eliminated, and accurate detection of the capacitance value can be achieved in real time.