1317 results about "Voltage variation" patented technology

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 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 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 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 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 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 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.

The invention relates to the technical field of new energy automobile electric control, and discloses a self-adaptive voltage dynamic stability control method for a new energy automobile converter. The method comprises the following steps: acquiring a real-time voltage time sequence data sequence of the new energy automobile converter in an operation period; performing voltage disturbance characteristic analysis on the real-time voltage time sequence data sequence based on a rated voltage interval of the converter, and identifying voltage disturbance modal information of the converter; then, according to an embedded voltage control strategy library and a voltage stability threshold condition, an initial voltage regulation and control instruction sequence is generated in combination with voltage disturbance modal information of the converter; performing voltage change trend prediction on the voltage disturbance modal information of the converter to obtain predicted voltage disturbance modal information; performing voltage control compensation optimization on the initial voltage regulation and control instruction sequence based on the predicted voltage disturbance modal information to generate an optimized voltage regulation and control instruction sequence; and performing adaptive voltage regulation on the new energy automobile converter according to the optimized voltage regulation instruction sequence.

The invention relates to the technical field of power system protection, in particular to an underground power distribution network single-phase grounding protection system and method based on a signal injection method. The system comprises a signal acquisition module, a measurement and control protection module and an online monitoring module. According to the invention, by injecting the independent direct current signal and combining a zero-sequence fundamental wave time sequence identification algorithm and a traveling wave distance measurement method, rapid detection, high-precision positioning and selective protection of the single-phase earth fault of the underground low-voltage power distribution network are realized, and the method is suitable for complex environments such as coal mines and metal mines; through insulation value on-line monitoring and electric leakage protection, the ground insulation value level of a line is reflected to the voltage change of an additional direct current signal and a reactor neutral point. A zero-sequence fundamental wave time sequence identification model is adopted for electric leakage fault judgment so as to judge the fault type. By outputting a relay signal, on-off control is performed on a protected branch, so that a fault line can be quickly cut off when a fault occurs, and equipment and a bus are protected from being damaged by the fault.

Disclosed herein is a single photon avalanche diode (SPAD) pixel circuit, including a SPAD having an anode coupled to a negative voltage and a cathode and a cascode transistor having a drain coupled to the cathode of the SPAD, a gate controlled by a cascode control signal, and a source. A readout circuit is coupled to the source of the cascode transistor and configured to detect a voltage change at the source of the cascode transistor and generate a pulse indicating an occurrence of an avalanche event. An active quenching circuit is coupled to the cathode of the SPAD and configured to detect an onset of the avalanche event and pull the cathode of the SPAD to a negative voltage to quench the avalanche event.

A measurement apparatus detects a voltage change in a power storage device. The measurement apparatus supplies constant current to the power storage device; measures voltage related to the power storage device supplied with the constant current; and detects the voltage change in the power storage device subjected to the measurement. The measurement apparatus also acquires the voltage change in the power storage device based on an electrical property serving as a reference of the power storage device.

The invention discloses a dynamic virtual impedance control method for multi-machine parallel connection of a network construction type energy storage converter, and belongs to the technical field of power electronics. The method aims to solve the problem that accurate reactive power distribution, circulating current suppression, dynamic response and voltage precision are difficult to consider in a multi-machine parallel system through fixed parameter virtual impedance. A dynamic adjustable virtual impedance module is introduced into the voltage outer loop output end of each converter, and virtual resistance and virtual inductance are calculated in real time based on locally measured output current, bus voltage change rate and adjacent machine reactive power deviation information; and the average reactive power of the system is estimated through a phase synchronization mechanism under the condition of no communication so as to realize multi-machine cooperation. According to the method, the reactive power distribution error is less than 5%, the bus voltage drop is less than 3%, the high-frequency circulating current is controlled within 5% of the rated current under all working conditions, and the dynamic performance and robustness of the system are remarkably improved.

The invention discloses a battery parameter identification method and system, belongs to the technical field of battery management, and solves the problems of high model dependency, weak anti-noise capability, difficulty in balancing real-time performance and precision, lack of aging adaptability and limited generalization capability of an existing method. The method comprises the steps of exciting a battery based on a mixed pulse power characteristic test or a dynamic working condition test, collecting dynamic test data of the battery, pre-constructing a dual-polarization model, identifying and analyzing the dynamic test data by the dual-polarization model, and outputting a parameter identification result. In the invention, the dual-polarization model comprises the ohmic internal resistance and the two RC parallel networks for representing electrochemical polarization and concentration polarization respectively, and the voltage change of the battery in the charging and discharging process can be reflected more accurately, so that the electrochemical process of the battery is described more accurately; the precision, robustness and full-life-cycle applicability of battery parameter identification are remarkably improved, and key technical support is provided for a high-safety and high-reliability battery management system.

The invention relates to the technical field of semiconductors, in particular to a high-temperature reverse bias test method, an electrostatic discharge protection structure and electronic equipment, and the method comprises the steps: providing the electrostatic discharge protection structure; determining an initial leakage current at the initial voltage, and determining an initial breakdown voltage at the initial current; heating the electrostatic discharge protection structure for a preset time at a preset temperature and a preset voltage, and determining a target leakage current of the heated electrostatic discharge protection structure under the initial voltage and a target breakdown voltage of the heated electrostatic discharge protection structure under the initial current; performing current change analysis on the initial leakage current and the target leakage current to obtain a current change result, and performing voltage change analysis on the initial breakdown voltage and the target breakdown voltage to obtain a voltage change result; and according to the current change result and the voltage change result, generating a high-temperature reverse bias test result of the electrostatic discharge protection structure. According to the invention, the reliability of the electrostatic discharge protection structure can be accurately evaluated.

The invention provides a battery health state assessment method which can be applied to the technical field of artificial intelligence. The battery health state evaluation method comprises the following steps: in response to an obtained charging and discharging voltage curve of a target battery, calculating the differential of voltage along with the change of charging capacity according to the charging and discharging voltage curve, and obtaining an incremental voltage curve; the differential of the charging capacity along with voltage change is calculated, and an incremental capacity curve is obtained; extracting a peak height, a peak position and a peak area in the incremental voltage curve, and a valley depth, a valley position and a valley area in the incremental capacity curve as health factors representing the target battery; and outputting the health state of the target battery based on the health factor of the target battery and a pre-trained support vector regression prediction model. The invention further provides a battery health state evaluation device and equipment, a storage medium and a program product.

The invention relates to the technical field of power distribution network optimization, in particular to a power distribution network voltage dynamic optimization control method, system and device and a storage medium, and the method comprises the steps: judging a mode interval in real time, and judging whether the system operates in a normal state or a fault state according to voltage fluctuation; calculating the photovoltaic residual capacity and the real-time charge state of the energy storage battery; according to the operation state of the system, judging the action state of the energy storage system and the photovoltaic operation mode, and calculating the total reactive power demand of the power distribution network system; on the basis of an improved TOPSIS algorithm, a power instruction is calculated by considering the voltage variation of each node in a power distribution network, the photovoltaic power regulation capability, the charge state of an energy storage system, the available residual capacity of energy storage and the voltage variation of a dominant node caused by unit power, and the power instruction is distributed to an optical storage node. According to the invention, power dynamic distribution under dual modes of a normal state and a fault state is set to ensure stable operation of voltage; and the power distribution network always operates in an optimal state.

The invention provides a method and device for determining the health state of a supercapacitor, and relates to the technical field of supercapacitors, and the method comprises the steps: obtaining the voltage variation and the current variation of the supercapacitor in the operation process; determining a target equivalent resistance value according to the voltage variation and the current variation; determining a target equivalent capacitance value according to the voltage variation and the current value in the corresponding time period; determining a resistance growth rate and a capacitance attenuation rate according to the target equivalent resistance value and the target equivalent capacitance value; and determining the health state of the supercapacitor according to the resistance growth rate and the capacitance attenuation rate. Therefore, the capacitance attenuation rate and the ESR growth rate can be extracted online based on the voltage data and the current data acquired in real time without interrupting the system or adding the test current in the equipment operation process, the process is simplified, and the accuracy and the reliability of determining the health state of the supercapacitor are also improved through the real-time data.

In an MMC-type power conversion device, a control device calculates an evaluation value representing the degree of variations in voltage of capacitors of individual converter cells. When this evaluation value exceeds a threshold value, the control device controls the converter cells as follows: (i) when current in a positive direction flows through a first converter cell with a voltage of the capacitor greater than a mean value, reducing an output time of positive voltage, (ii) when current in a negative direction flows through the first converter cell, increasing an output time of positive voltage, (iii) when current in the positive direction flows through a second converter cell with a voltage of the capacitor smaller than a mean value, increasing an output time of positive voltage, or (iv) when current in the negative direction flows through the second converter cell, reducing an output time of positive voltage.

The utility model provides a CP sampling circuit of an automobile alternating current charging pile, and relates to the technical field of CP sampling circuits, the technical scheme provided by the utility model adopts a double-path sampling design, CP signals in two forms of PWM and DC can be processed at the same time, and the signal processing precision is improved through multi-stage amplification and filtering. The overall structure of the circuit enables the circuit to quickly respond to the voltage change of the CP signal in different charging stages and accurately identify different voltage levels, so that the sampling speed and accuracy of the automobile AC charging pile to the CP signal can be improved.

The invention discloses a submarine observation network power supply system protection method based on traveling wave extreme value time, and relates to the technical field of submarine power grid protection, and the method comprises the steps: determining the layout position of a protection device according to a network structure, a power supply path and node importance, and dividing a system into protection regions defined by adjacent protection devices; voltage signals are collected in real time, first-order differential processing is carried out, and fault occurrence is judged by comparing the voltage change rate with a preset threshold value; recording current traveling wave data before and after the fault and carrying out Gaussian filtering noise reduction; calculating the extreme value time of the traveling wave by using a differential gradient algorithm; comparing the time difference of traveling wave extreme values on two sides of the protection area to judge the fault direction; judging a fault area in combination with the extreme time and a preset threshold value; and when the forward direction criterion and the intra-region criterion are met at the same time, a protection action is triggered. The method has the advantages that high-reliability fault positioning and rapid isolation can still be achieved under the communication failure scene, and the problem of remote fault and high-resistance fault recognition is effectively solved.

The invention relates to a terminal voltage flexible regulation and control method, and the method comprises the following steps: presetting target voltage parameters which comprise an amplitude value, a frequency and an initial phase angle; calculating a three-phase sinusoidal voltage reference signal based on a virtual synchronous machine algorithm according to the target voltage parameter; according to the three-phase sinusoidal voltage reference signal, generating a driving signal by using pulse width modulation, and controlling the on and off of an IGBT power switch device to generate a three-phase sinusoidal compensation voltage; injecting the three-phase sine compensation voltage into the tail end of a power grid; monitoring the voltage state of the power grid in real time, and calculating the deviation between the actual voltage of the tail end of the power grid and the target voltage parameter; and according to the deviation, adjusting a control parameter in the virtual synchronous machine algorithm, and updating the three-phase sine compensation voltage to compensate the voltage deviation at the tail end of the power distribution network. Voltage deviation can be compensated in time, and the problem of voltage change caused by large fluctuation of electrical load can be effectively solved.

The invention relates to a relay pull-in self-learning method and circuit, and the method comprises the steps: collecting a front-end voltage value connected to the front end of a relay conduction path and a rear-end voltage value connected to the rear end of the relay conduction path, so as to calculate and generate corresponding voltage change information, judging whether the voltage change information meets a pull-in condition for determining that the relay is pulled in or not; if the pull-in condition is met, the time offset of the current actual pull-in moment of the relay relative to the alternating current zero crossing point is calculated according to the voltage change information; according to the time offset, the next actuation control signal sending moment of the relay is corrected in advance, so that the time difference between the next actual actuation moment of the relay and the alternating current zero crossing point meets the set offset threshold condition, and the actuation state of the relay is sensed in real time; therefore, the relay is closed at the moment closer to the alternating current zero crossing point, the impact current is effectively reduced, and the service life of the relay is prolonged.

The invention relates to the technical field of power supply management, in particular to a transient response optimization method based on a linear voltage regulator, and the method comprises the steps: obtaining transient response data of the linear voltage regulator when a load suddenly changes, and judging whether the linear voltage regulator enters a transient early warning state or not. And if entering the early warning state, carrying out high-frequency noise threshold segmentation on an output voltage waveform, extracting voltage change rate characteristics, constructing a compensation efficiency model based on dynamic response time and effective compensation bandwidth, calculating an optimal open-loop compensation coefficient, generating a compensation control instruction, and driving a compensation network to carry out dynamic compensation. And if the pre-warning state is not entered, ripple uniformity data of the output voltage is acquired, a deviation matrix of an actual ripple distribution curved surface and an ideal ripple distribution plane is determined, and whether a local ripple abnormal region exists is determined. According to the method, through dynamic monitoring and intelligent compensation, the transient response speed and stability of the linear voltage regulator are improved, and high-frequency noise processing and ripple uniformity are optimized.

The invention provides a control method for participating in transient reactive power support of an offshore wind power grid-connected system by energy storage and a related device. The control method comprises the following steps: acquiring a voltage deviation value and a voltage change rate of a grid-connected point of the offshore wind power grid-connected system; judging whether the system is in a steady state according to the voltage deviation value; if yes, generating a given reactive power reference value as an energy storage reactive power instruction; if not, double-layer fuzzy control reasoning is carried out based on the voltage deviation value and the voltage change rate, and a dynamic reactive power reference value is obtained to serve as an energy storage reactive power instruction; and performing transient support control of energy storage according to the energy storage reactive instruction until the energy storage is finished, and participating in transient voltage recovery. Through double-layer fuzzy control reasoning, reactive power can be dynamically adjusted in real time according to the power grid state, reactive capacity waste is avoided, and the transient reactive supporting capacity in different transient scenes is improved. Meanwhile, the charge state of energy storage equipment is considered, unreasonable charging and discharging are avoided when the reactive power requirement of a power grid is met, and the energy storage service life is prolonged.

The invention discloses a virtual power plant flexible resource layering and partitioning method and device and a storage medium, and relates to the technical field of virtual power plants, and the method comprises the steps: obtaining a response characteristic interval model constructed through response characteristic parameters of each flexible resource; based on a response characteristic interval model, evaluating the voltage influence of each flexible resource on each physical node through a voltage sensitivity analysis interval model to obtain each voltage change interval; based on each voltage change interval, performing clustering division on each flexible resource to obtain main resource features of a plurality of aggregation nodes; and returning to execute the step of evaluating the voltage influence of each flexible resource on each physical node through the voltage sensitivity analysis interval model, iteratively optimizing each aggregation node, and when the change rate of the aggregation target function value is smaller than a preset threshold value, determining a layering and partitioning result of each flexible resource. The problem of security risk caused by static layering and partitioning of flexible resources of the virtual power plant is solved, so that the layering and partitioning of the flexible resources are matched with the latest state.

The invention relates to a voltage regulation method and device and computer equipment, and relates to the technical field of circuit parameter regulation. The method comprises the following steps: acquiring a voltage tracking difference value of a target circuit at each moment, wherein the voltage tracking difference value at each moment changes along with the output voltage of the target circuit; according to the output voltage of the target circuit at the previous moment of the current moment and the voltage tracking difference value at the current moment, obtaining a reference voltage at the current moment; and based on the reference voltage at the current moment and the output voltage at the previous moment, controlling the switching frequency of the target circuit at the current moment so as to adjust the initial output voltage of the target circuit to the open-circuit voltage corresponding to the target circuit. By adopting the method, the initial output voltage of the target circuit can be smoothly transited to the open-circuit voltage corresponding to the target circuit, and the stability of the target circuit is guaranteed.

The invention belongs to the field of power device driving, particularly relates to the technical field of crosstalk suppression, and more particularly relates to a crosstalk suppression driving circuit. Through cooperative work of the driving module, the detection module, the buffering module and the clamping module, crosstalk is effectively suppressed while the switching speed is ensured. The driving module ensures normal switching action of the power device; the detection module converts the drain voltage change rate into a detection signal in real time, and recognizes the crosstalk risk in advance; the buffer module suppresses forward crosstalk by absorbing grid forward voltage spikes; the clamping module immediately conducts a low-impedance path from the grid electrode to the negative power supply when the detection signal exceeds a threshold value, and negative crosstalk is quickly eliminated. According to the design, the suppression circuit is only activated when the voltage change rate exceeds the standard, switching delay caused by a traditional fixed buffer circuit is avoided, accurate and rapid crosstalk suppression can be achieved, and finally the suppression effect and the system reliability are remarkably improved while the high-speed switching performance is maintained.

The invention belongs to the technical field of electronic circuits, and provides a low-dropout linear voltage stabilizing circuit, a low-dropout linear voltage regulator, a power supply device and electronic equipment. The low-dropout linear voltage stabilizing circuit comprises a bias module, an input module, an intermediate stage module, an output module, a first compensation module and a second compensation module, the intermediate stage module is connected with the input module, the output module, the first compensation module, the second compensation module and the bias module, and the output module is connected with the input module, the first compensation module and a load. The input module is connected with the bias module. According to the application, the first zero point which is positively correlated with the load current and irrelevant to the output voltage is generated through the first compensation module, namely, the first zero point can be increased along with the increase of the load current, is reduced along with the reduction of the load current, and is not influenced by the output voltage; therefore, the tracking compensation of the load current is realized, and the purpose that the tracking compensation effect does not change along with the output voltage is achieved.