3678 results about "Current transducer" patented technology

The invention relates to the technical field of motor fault diagnosis, in particular to a motor fault diagnosis algorithm based on multi-sensor fusion, and the algorithm comprises the steps: injecting a step excitation signal into a motor, synchronously collecting the original response waveforms of vibration and current sensors, and calculating the inherent response delay. Establishing a mapping relation library of delay values and current sensor filtering parameters, calling the delay values in real time according to the filtering parameters, performing reverse time offset compensation on a current harmonic signal time sequence, performing time alignment on the two types of data, finally performing cross-domain coupling analysis on the aligned data, extracting vibration pulse peak frequency and current harmonic fluctuation quantity, and determining the vibration pulse peak frequency and the current harmonic fluctuation quantity. Early faults are judged by combining the bearing outer ring fault characteristic frequency band and the load rate dynamic threshold value, graded alarm is generated by tracking characteristics, the problem of fault false judgment and missed judgment caused by sensor data space-time dislocation is solved, and the early fault diagnosis accuracy of the motor is improved.

The invention relates to a multi-sensor fault feature fusion diagnosis method for electrical equipment, which comprises the following steps: synchronously acquiring operation data of the electrical equipment through a vibration sensor, a temperature sensor, a current sensor and an ultrasonic sensor, dynamically adjusting the sampling frequency according to the physical characteristics of each sensor, and the sampling rate of the temperature signal is not lower than 1Hz. Through a multi-source sensor data synchronous acquisition and time sequence alignment technology and a signal alignment method combining a dynamic time warping (DTW) algorithm and Hilbert-Huang transformation, the problem of time asynchronization of heterogeneous sensor data such as vibration and temperature is solved, so that the time alignment precision of multi-source data is improved, the feature extraction accuracy is improved, and the accuracy of feature extraction is improved. Through hierarchical feature extraction and graph convolutional network fusion, a feature incidence matrix based on mutual information is constructed, deep correlation between vibration signal TKEO features and cross-modal features such as current harmonics is mined by using GCN, the feature dimension is reduced, and the fault feature separability index is improved.

The embodiment of the invention provides a differential Hall current sensor and a manufacturing method thereof, and belongs to the technical field of semiconductors. The differential Hall current sensor comprises a current bar; the insulating layer is bonded on the upper surface of the current bar; the at least two Hall elements are symmetrically arranged on the two sides of the upper surface of the insulating layer in the current direction; and the at least one deflection magnetism gathering block is attached to the magnetic induction surfaces of the at least two Hall elements and is used for deflecting a magnetic field component of the current magnetic field in the direction parallel to the magnetic induction surfaces of the Hall elements into a magnetic field component in the direction perpendicular to the magnetic induction surfaces of the Hall elements. According to the differential Hall current sensor, the current magnetic field is gathered through the deflection magnetism gathering block to form a conduction magnetic circuit, the directions of the magnetic field components are changed, the Hall element obtains the magnetic field intensity formed by superposing the magnetic field components in the two directions, and the measurement sensitivity is improved.

To provide a power management system which can suppress significant change of a power adjustment amount when a plurality of electronic vehicles which calibrate a current sensor participate in power adjustment.SOLUTION: A power management system 1 comprises: a plurality of electric vehicles 10; and a server 200 (power transmission instruction device). Each of the plurality of electric vehicles 10 comprises a current sensor 12 which detects current which flows by external discharge (power transmission) and calibrates the current sensor 12 for every predetermined period. The server 200 adjusts start timing of the external discharge by at least a part of the plurality of electric vehicles 10 so that timing of calibration of the plurality of electric vehicles 10 deviates when it is predicted that resource total power (the total amount of a power amount to be exchanged by the power transmission) becomes smaller than a lower limit value (predetermined threshold) of an allowable range resulting from overlap of the timing of calibration of the plurality of electric vehicles 10.SELECTED DRAWING: Figure 2

The invention provides a split type direct current charging multi-split group charging and group control control system, and belongs to the technical field of split type direct current charging piles. The split type direct current charging system comprising a main control cabinet, a power distribution unit, a charging pile terminal and other hardware architectures is constructed; a voltage monitoring unit, a current sensor module, a harmonic filter and other multi-dimensional sensor networks are integrated to acquire power grid state data in real time, and a sliding time window method is used to carry out segmented analysis on the data to extract power grid characteristic parameters; establishing a multi-objective optimization model comprising a power balance equation and a power grid stability equation to calculate an optimal power distribution matrix, adopting a neural network to realize intelligent distribution and dynamic balance adjustment of the power of each charging pile terminal, and starting an emergency power redistribution mechanism to ensure stable operation of the system when the power grid is detected to be abnormal. The technical problem of unbalanced power distribution of the multi-pile charging system caused by power grid voltage fluctuation and harmonic pollution is solved.

The invention discloses an intelligent operation and maintenance method. The method comprises the steps of deploying a vibration sensor, a temperature sensor, a current sensor and a pressure sensor at key operation parts of building equipment; receiving an original data flow of each sensor through an edge computing node; performing space-time alignment on the processed sensor data and the equipment operation state parameters; establishing a digital twin model library on the cloud server; and performing mode comparison on the real-time sensor data stream and the fault features in the digital twin model library through a fuzzy matching algorithm, and when the vibration frequency domain features have amplitude sudden change exceeding a baseline value in a preset frequency band, the temperature change rate exceeding a preset threshold and the current harmonic distortion rate exceeding a set proportion, triggering a grading early warning signal. According to the invention, the accuracy, the real-time performance and the intelligent level of operation and maintenance of the building equipment can be obviously improved.

The invention discloses a power battery state real-time monitoring system, and relates to the technical field of new energy automobiles, and the system comprises the following components: sensor network construction: installing a voltage sensor, a temperature sensor, a current sensor and an internal resistance monitoring sensor on each single battery of a power battery pack to form an omnibearing and high-density monitoring network; according to the integrated fault diagnosis technology, the comprehensive and high-density sensor network is constructed, key parameters of voltage, temperature, current and internal resistance of each single battery in the battery pack are collected in real time, comprehensiveness and accuracy of data are ensured, multiple advanced fault diagnosis algorithms are combined, and the fault diagnosis accuracy of the battery pack is improved. According to the method, characteristics can be rapidly extracted from mass data according to a battery comprehensive fault identification index formula, a battery physical model prediction index and an abnormal value detection index, and pattern identification is carried out, so that accurate judgment of a fault type of a single battery and accurate positioning of a fault position are realized.

The embodiment of the invention provides a differential Hall current sensor and a manufacturing method thereof, and belongs to the technical field of semiconductors. The differential Hall current sensor includes: a substrate; the magnet yoke is provided with a semi-enclosed structure formed by a bottom surface and two side surfaces positioned on the same side of the bottom surface, and the bottom surface is bonded on the substrate; the current bar is placed in the cavity of the semi-surrounding structure and allows two end parts of the current bar to extend out of the semi-surrounding structure; the insulating layer is arranged on the upper surface of the current bar and located in the cavity; the at least two Hall elements are symmetrically arranged on the two sides of the upper surface of the insulating layer in the current direction; the at least two groups of magnetism gathering blocks are attached to the magnetic induction surfaces of the at least two Hall elements; at least two groups of magnetism gathering blocks and the magnet yoke form a conducting magnetic circuit, and the magnetic field component of the current magnetic field in the parallel direction of the magnetic induction surface is deflected into the magnetic field component in the vertical direction. According to the differential Hall current sensor, the Hall perceptible magnetic field intensity is enhanced through the conduction magnetic circuit of the gathered current magnetic field, and the measurement sensitivity is improved.

The invention discloses a cable partial discharge detection method and system, and the method comprises the steps: installing sampling sensor groups on a detected cable at a preset interval, and each group at least comprises a current sensor and an ultrasonic sensor; synchronously sampling and preprocessing the high-frequency current signal and the ultrasonic signal; extracting current waveform characteristics and a first time stamp of arrival of the first pulse, and extracting sound wave pulses in the ultrasonic signals and a second time stamp of arrival of the sound wave pulses; and calculating a time difference, if the time difference is smaller than a preset threshold value and the waveform amplitude similarity is within a preset range, determining that no failure partial discharge exists, otherwise, positioning a failure position. According to the method, the acoustoelectric signals are acquired cooperatively through multiple sensors, interference is eliminated in combination with time difference and waveform similarity criteria, the detection reliability and the positioning precision are effectively improved, and the method is suitable for cable insulation state monitoring and fault early warning.

The embodiment of the invention provides an inverter, a motor controller and a vehicle, and the inverter comprises an integrated drive control board which comprises a drive part and a control part which are disposed on the same circuit board; the onboard current sensor is used for detecting direct current and converting the direct current into three-phase alternating current; the integrated liquid cooling heat dissipation capacitor comprises a high-voltage film capacitor and a liquid cooling heat dissipation device, and at least part of the high-voltage film capacitor is in contact with the liquid cooling heat dissipation device. At least part of the power semiconductor device is in contact with the liquid cooling radiator, the high-voltage film capacitor is connected with a positive electrode and a negative electrode of an upper bridge of the power semiconductor device through a positive electrode switching copper bar and a negative electrode switching copper bar respectively, and a lower bridge of the power semiconductor device is connected with the three-phase copper bar. The integrated liquid cooling heat dissipation capacitor and the liquid cooling heat dissipation device are arranged to dissipate heat of the power semiconductor device and the high-voltage thin film capacitor, and the high-voltage thin film capacitor and the power semiconductor device can be dissipated at the same time through one liquid cooling heat dissipation device.

A system comprising: a conductor having a through-hole and a first notch that are formed therein, the through-hole and the first notch being arranged to define, at least in part, a first branch of the conductor, and the through-hole also being arranged to define, at least in part, a second branch of the conductor; and a current sensor that is disposed directly above the first branch of the conductor and the side of the second branch of the conductor, such that no portion of the current sensor is situated directly above the second branch.

The invention provides a three-phase current sampling circuit calibration method and system, and belongs to the technical field of permanent magnet synchronous motor three-phase current sampling calibration, and the method comprises the following steps: sequentially giving UVW three-phase current through a motor controller; respectively acquiring three-phase current data through a current sampling circuit in the motor controller and an external current sensor; performing linear fitting on the acquired three-phase current data to obtain a current sampling compensation coefficient of the UVW three-phase current sampling circuit; and multiplying the current sampling compensation coefficient by an initial sampling coefficient of the current sampling circuit, and calculating to obtain an actual sampling coefficient. The current sampling compensation coefficient can more accurately reflect the performance of the current sampling circuit under the actual working condition, so that errors and deviation are reduced, and the sampling precision of the current sampling circuit under the large current is improved.

The invention discloses a safe charging method for an intelligent data line, and relates to the technical field of data lines. Through current fluctuation detection and temperature and humidity anomaly detection, a current sensor can accurately capture instantaneous fluctuation, timely trigger a power adjustment or current limiting mechanism and prevent equipment damage caused by surge in a rapid charging scene; in addition, the temperature sensor starts a trickle charging mode when being overheated, and the humidity sensor prevents the risk of short circuit through power-off protection. Secondly, through cooperative work of a wireless communication module and a mobile phone terminal, a data line can dynamically adjust the charging power, and feed back a real-time risk score and abnormal information to a mobile phone to remind a user to take measures, so that the interaction capability between the user and charging equipment is enhanced, and the user is helped to identify potential hidden dangers in a charging environment in an early stage; besides, by analyzing the charging time, the use load and the risk triggering data of the user, future abnormal scenes can be predicted, targeted suggestions can be provided, and the user experience is improved.

The invention relates to the technical field of power detection, and provides a current transformer fault diagnosis method. The method comprises the following steps: establishing a current transformer state model; acquiring three-phase current data under different state types, dividing labels, and making a current transformer fault data set; constructing a current transformer fault diagnosis model, and training the model by taking the three-phase current data as an input vector group and the probability of the label corresponding to the state type of the current transformer as an output vector to obtain a to-be-tested current transformer fault diagnosis model; and testing the accuracy of the to-be-tested current transformer fault diagnosis model through the test set, and verifying the generalization performance of the model. By further considering more complex drift faults and noise faults, the invention provides a current sensor fault diagnosis method based on a novel CNN series connection LSTM and fusing a time sequence attention mechanism, and solves the technical problem of insufficient feature extraction of a current transformer fault diagnosis method in the prior art.

The utility model relates to a power module, an electric control inverter and a vehicle. The power module comprises a power module body, a magnetic core and a current sensor. The power module body comprises a base, a power unit located on the base and a plurality of phase terminals which extend outwards from the power unit and are used for transmitting phase current; the magnetic cores and the phase terminals are arranged in a one-to-one correspondence mode, in a plane perpendicular to the extending direction of the phase terminals, the magnetic cores are arranged around the phase terminals and provided with openings, the current sensors and the magnetic cores are arranged in a one-to-one correspondence mode, and the current sensors are arranged in the openings. According to the current sensor, the magnetic cores are integrated in the power module, and the magnetic cores are arranged around the corresponding phase terminals, so that magnetic core barriers capable of playing a magnetic field shielding role exist between the phase terminals of the power module, the anti-crosstalk capability between the phase terminals is improved, and the sampling precision of the current sensor is further improved.

The invention discloses a current reconstruction method for sampling of double Hall current sensors of a permanent magnet synchronous motor, relates to a current reconstruction method, and aims to solve the problems that the cost and the capacity of a control system are increased and a peripheral circuit is more complicated due to the fact that three Hall current sensors need to be adopted for current sampling in a traditional method. The method comprises the following steps: step 1, installing a Hall current sensor H1 and a Hall current sensor H2; step 2, setting sampling moments of the Hall current sensor H1 and the Hall current sensor H2; 3, setting the minimum sampling time of the Hall current sensor H1 and the Hall current sensor H2; 4, current reconstruction is carried out according to the current values is1, is2 and i0 obtained by sampling of the Hall current sensor H1 and the Hall current sensor H2, and the current values of the A phase, the B phase and the C phase are obtained. The invention belongs to the technical field of common direct current bus type open winding permanent magnet synchronous motor control.

According to the cable multi-parameter fusion sensor and method, in the cable multi-parameter fusion sensor, a shielding shell is of an open-close type metal annular structure; the zero-flux sensor module is arranged on the inner layer of the shielding shell so as to detect a cable sheath ring current signal; the pulse current sensor module is arranged on the outer side of the zero-flux sensor module so as to detect a cable partial discharge pulse current signal and an overvoltage impact current signal; the magnetic shielding layer is arranged between the zero-flux sensor module and the pulse current sensor module to shield low-frequency magnetic field interference; the zero magnetic flux sensor module and the pulse current sensor module share the shielding shell to form an electromagnetic shielding structure.

The invention relates to the technical field of energy consumption management, and particularly discloses a 12-axis PCB drilling machine energy consumption management system based on resource dynamic scheduling, which collects input and output differential current data and power factor change rate data in real time by deploying a current sensor and a power monitoring module on each motion axis driver; a current anomaly characteristic value and a power stability characteristic value are extracted through a Bayesian point-of-change detection algorithm and a Hilbert-Huang transform method, and a composite energy consumption anomaly characteristic vector is constructed; the random forest model is combined to intelligently score the energy consumption state of each shaft, the working mode of the abnormal shaft is dynamically adjusted according to the scoring result, and self-adaptive scheduling and optimization of energy consumption are achieved; the system continuously optimizes operation parameters through a closed-loop feedback mechanism, the energy consumption of the whole machine is effectively reduced on the premise of guaranteeing the processing efficiency, the intelligence, refinement and greenization levels of equipment operation are improved, and the system has good engineering application value and popularization prospects.

A fastener driver includes a motor, a trigger, and a lifting assembly operable to be moved by the motor. The fastener driver includes a speed sensor, a voltage sensor, and a current sensor. A controller is configured to provide, in response to actuation of the trigger, power to the motor, receive speed signals from the speed sensor indicative of the speed of the motor, receive voltage signals from the voltage sensor indicative of the voltage of a battery pack, and receive current signals from the current sensor indicative of the current of the motor. The controller determines a torque of the motor based on the signals, determines whether the torque of the motor is less than or equal to a torque threshold, and activate an electronic clutch, in response to the torque of the motor being less than or equal to the torque threshold, to electronically brake the motor.

The invention relates to the technical field of brushless gear motor control, and discloses a brushless gear motor based on multiple sensors and a control method thereof, and the motor comprises a motor body, a monitoring module and a control part. The monitoring module is electrically connected with the motor body, the monitoring module is provided with a temperature sensor, a rotating speed sensor, a current sensor and a load sensor, and the monitoring module is configured to monitor the motor body in real time. The control part is electrically connected with the monitoring module and the motor body, and the control part is configured to obtain structural data, historical monitoring data and real-time monitoring data of the motor body, determine the temperature state of the motor body according to the structural data, the historical monitoring data and the real-time monitoring data, and send the temperature state to the motor body. The control part is further configured to determine the energy efficiency loss amount of the motor according to the temperature state and adjust the operation data of the motor body according to the energy efficiency loss amount. According to the invention, the structure data, the historical data and the real-time data are comprehensively analyzed, so that the motor is accurately controlled.

A time-based wireless pairing operation between a medical device, such as a patient bed, and a wall module in a patient room is initiated in response to a power plug of the medical device being plugged into a power receptacle carried by the wall module. Times determined by timers of the medical device and the wall module are compared by the wall module or by the medical device so that wireless pairing occurs only with the medical device that was plugged into the wall module. Different types of plug detectors used in the wall module to detect connection of the power plug include optical detectors, mechanical switches, and current sensors.

The invention provides an automatic calibration method for measurement power of an electric meter and an inverter, a communication end of the inverter is in communication connection with the electric meter, a voltage sampling port of the inverter is used for sampling three-phase voltage and neutral line voltage, and a current sampling port of the inverter is used for sampling three-phase current; a voltage sampling port of the ammeter is used for sampling three-phase voltage and neutral line voltage, and a current sampling port of the ammeter is used for sampling three-phase current through a current sensor; the method comprises the steps of controlling an inverter to work in a wiring detection state when neutral line voltage sampling wiring of an electric meter is correct; and adjusting the inversion power of at least one phase of the inverter, and determining the current variable quantity, the active variable quantity and the reactive variable quantity of each phase of the electric meter before and after the power change so as to identify the wiring phase sequence of the electric meter and the installation direction of the current sensor and obtain the actual feed network power of at least one phase of the inverter. According to the invention, re-wiring is not needed when wiring errors exist in the ammeter, the power fed back by the ammeter can be automatically corrected, and the working efficiency is greatly improved.

The invention provides a surface roughness monitoring method of an embedded physical prediction model. According to the method, in a model training stage, cutting force signals and three-phase current signals of a main shaft servo motor in the machining process are collected through a dynamometer and a current sensor, the signals are preprocessed and then input into a cutting force calculation module, cutting force under the corresponding current signals is output, and the obtained cutting force is used for calculating a surface roughness theoretical value; and the current signal, a current signal and a processing parameter are input into a surface roughness calculation module, and a surface roughness monitoring model is trained. In the machining stage, the roughness value of the machined surface of the workpiece at the moment is calculated in real time by collecting the three-phase current signals of the main shaft servo motor in the machining process, and it is avoided that sensors such as a vibration sensor or an acoustic emission sensor or a dynamometer are installed in a machine tool in the actual machining stage.

A power semiconductor module of a power electronic system includes: a power electronic substrate; a power semiconductor die arranged on and electrically coupled to a first side of the substrate; a plastic frame arranged at the first side and defining an interior volume of the module; and a load current contact electrically connected to the first side and partially exposed from the frame. The frame includes a recess above a side of the load current contact facing away from the substrate. A driver board arranged above the module includes circuitry configured to drive power circuitry of the module. A current sensor arranged on and electrically coupled to a side of the driver board facing the module is configured to detect an alternating current flowing through the load current contact. The sensor is arranged at least partially within the recess. The frame electrically isolates the sensor from the load current contact.

The invention relates to a current sensor chip packaging structure and a packaging method. The current sensor chip packaging structure comprises a bus frame and a chip which are packaged through a plastic package body, the side, provided with the chip bonding pad, of the chip is defined as the front face of the chip, only one side of the front face is configured to be opposite to the back face of the bus frame, the chip bonding pad is arranged on the other side, extending out of the bus frame, of the front face, and a sensor element is arranged on the side, right opposite to the bus frame, of the front face of the chip. A gap between the chip and the bus frame is provided with an isolation layer, and the front surface is connected to the back surface of the bus frame through the isolation layer. According to the current sensor chip packaging structure and the packaging method, the front surface of the chip is connected to the back surface of the bus frame through the isolation layer, and the sensor element is arranged at the position opposite to the front surface of the chip, so that the distance between the sensor element and the bus frame is minimized, and the reliability of the current sensor chip is improved by minimizing the distance between the sensor element and the bus frame. Sensitivity and measurement precision of the sensor are remarkably improved, and the problems of reduction of isolation voltage endurance capability and process fluctuation are avoided.

The invention relates to a hybrid commutation converter valve operation method and a hybrid commutation converter valve, and the method comprises the steps: obtaining a phase current measurement value of an AC wire inlet of the hybrid commutation converter valve, obtaining the bridge arm conduction state information of the hybrid commutation converter valve, and combining a preset corresponding relation among a bridge arm conduction state, a phase current and a bridge arm current, and obtaining a phase current measurement value of an AC wire inlet of the hybrid commutation converter valve; and analyzing and calculating to obtain the bridge arm current of the current conduction bridge arm. According to the scheme, the bridge arm current of the hybrid commutation converter valve is indirectly obtained by measuring the phase current measurement value of the alternating current wire inlet of the hybrid commutation converter valve and combining the bridge arm conduction state information for analysis, a current sensor does not need to be installed on the bridge arm of the hybrid commutation converter valve, the influence of electromagnetism and vibration is avoided, and the reliability of the hybrid commutation converter valve is improved. And the accuracy of the obtained bridge arm current is ensured. In this way, active turn-off monitoring of the hybrid commutation converter valve is achieved through the bridge arm current with high accuracy, and the operation reliability of the hybrid commutation converter valve is effectively improved.

The invention discloses a SiC MOSFET hard switching loss measurement method and system without a current sensor, which cancel current measurement on the basis of a double-pulse measurement method and obtain a current waveform by analyzing voltage waveform change characteristics. Wherein the measurement of the drain-source voltage is very simple and convenient, the layout and the size of the converter are not influenced, and the measurement time is very short. The method can be popularized to any topology with an equivalent half-bridge commutation loop.

An adaptive IoT power plug system for intelligent load management and remote control, consisting of: a power plug housing configured to be inserted between a power outlet and an electrical appliance; an embedded sensor array comprising at least one voltage sensor, at least one current sensor, and at least one power sensor and configured to continuously monitor the electrical parameters of the connected device; a microcontroller unit (MCU) operatively coupled to the sensor array and configured to execute a load prioritization technique that dynamically determines power allocation based on real-time consumption data and user-defined priority levels for one or more connected loads; a semiconductor switching module electrically connected to the MCU and configured to selectively interrupt or modulate the power supply to the connected device based on commands from the load prioritization technology; a wireless communication module integrated into the MCU for bidirectional data exchange via at least one wireless protocol selected from Wi-Fi, Zigbee or Bluetooth Low Energy; a user interface that can be accessed remotely via a mobile or web application and enables the configuration of load priorities, real-time monitoring of power consumption, scheduling of device operation, and manual override of switching commands; and a power management subsystem including a power harvesting module configured to provide supplemental power to the system's electronic components, thereby reducing dependence on the main power source; The system autonomously adjusts the power distribution between multiple connected devices to load fluctuations and predefined user priorities in order to optimize energy efficiency and prevent overloading of the circuit.

The invention discloses an electric meter data storage method of a single-phase cost-control electric energy meter, and relates to the technical field of intelligent electric meter data processing, and the storage method comprises the following specific steps: S100, data acquisition and characteristic pro-analysis: acquiring voltage, current and power data of the single-phase cost-control electric energy meter through a voltage sensor and a current sensor, by integrating the voltage sensor and the current sensor, real-time and accurate acquisition of key power utilization data of voltage, current and power of the single-phase charge-control electric energy meter is realized, and by introducing a dynamic time window setting mechanism, the length of a time window is automatically adjusted according to the fluctuation amplitude of the data, so that the accuracy of power utilization is improved. It is ensured that a window is shortened to capture transient changes when data fluctuates violently, the window is prolonged to reduce redundant collection when the data is stable, the flexibility and accuracy of data collection are improved through intelligent adjustment, subsequent data processing can be conducted based on richer and more detailed feature information, and the data collection efficiency is improved. And the intelligent level of the whole data storage system is obviously improved.

The utility model relates to the technical field of servers, in particular to a server power supply heat dissipation device, which comprises a CPLD (complex programmable logic device) arranged on a power supply backboard and connected with a BMC (baseboard management controller) through an I2C (inter-integrated circuit) link; the CPLD is connected with a first port of the multiplexer, and the BMC is connected with a second port of the multiplexer; a third port of the multiplexer is connected with the power management bus; the CPLD is connected with a control pin of the multiplexer so as to control the multiplexer to communicate the first port to the third port or communicate the second port to the third port; the power management bus is connected with a voltage sensor and a current sensor which are arranged at the downstream of the power converter; and the CPLD is connected with the power supply fan driving chip.