33results about How to "Fast fault diagnosis" patented technology

The invention discloses a diagnosis method for an active power filter switching device open-circuit fault based on model reference analysis. The diagnosis method includes the steps that on the basis of building an actual operation model of active power filter main circuits, a reference model is constructed; measurable active power filters in all sampling periods are used for outputting three-phase compensating currents, and voltage residual errors are generated according to reference analysis of the model; by setting a threshold value and two judgment flag bits, the residual errors are evaluated to detect whether the open-circuit fault happens on an APF switching device or not in real time; if the fault happens, the specific position where the open-circuit fault of the switching device happens is diagnosed according to the two judgment flag bits. The diagnosis method is effectively used for monitoring the active power filters on line and diagnosing faults, and electric, electronic and electric energy quality control devices such as the active power filters and reactive compensators operate reliably and safely.

The invention, which relates to the technical field of the analog circuit fault diagnosis, provides an improved particle swarm optimization diagnosis method and system of an analog non-linear direct current circuit. With the method and system, a problem that the existing pattern-classification-based fault diagnosis method does not has the enough diagnosis capability for the unknown fault state and a multi-fault state of the analog circuit can be solved. The method comprises: establishing a fault diagnosis equation; calculating fitness values of all particles; calculating a unified inertia weight of all particles; calculating changes of the fitness values; determining a final value of the inertia weight of all particles at current iteration; updating speeds and positions of all particles in the particle swarm; and repeating all above-mentioned steps until method convergence is realized. Compared with the standard PSO algorithm, the method and system based on the technical scheme have the high fault diagnosis coverage rate and the fast fault diagnosis speed.

The invention discloses a phase failure diagnosis method of a permanent magnet synchronous motor (PMSM) drive system of an electric vehicle. According to the method, a drive failure of the PMSM drive system of the electric vehicle is detected based on detectable stator current, and a phase failure of the PMSM drive system can be diagnosed in real time in an on-line manner. The method can be applicable to running conditions of the electric vehicle, has technical advantages of high failure diagnosis speed, high diagnosis precision and the like, and is easily integrated with the control of the electric drive system to realize the safe and reliable running of the electric drive system.

The invention discloses an electro-magnetic doubly salient motor power converter open-circuit fault diagnosis method, and relates to the technical field of fault diagnosis. According to the method, the position of a current sensor in a power converter topology is changed, a first current sensor is placed on a direct-current bus and used for detecting bus current, and a second current sensor is placed on an upper bridge arm power tube bus and used for detecting upper bridge arm power tube breakover current; in combination with the working state of the motor, the phase current is indirectly obtained through the relationship between the breakover current and the phase current of the upper bridge arm power tube to realize the normal operation of the motor; according to different current flowing paths corresponding to faults of different power tubes, fault diagnosis is realized by combining driving signals and position signals of the power tubes. Compared with a traditional fault diagnosis method without changing the positions of the current sensors, the method has the advantages that the number of the current sensors is reduced, open-circuit fault positioning of the power tube can be quickly realized, and the implementation method is simple and accurate.

The invention relates to the technical field of power. The invention provides a voiceprint-based intelligent health monitoring method for power equipment. The voiceprint-based intelligent health monitoring method comprises the following steps: S1, arranging a voiceprint signal collector on the site of the power equipment, and uniformly deploying a plurality of wireless sensors on each piece of power equipment to acquire voiceprint signals of each piece of equipment working on the site of the power equipment; S2, enabling the voiceprint signal collector to be composed of a Bluetooth wireless communication module, a data packet forwarding module, a 4G communication module and a power supply module; S3, enabling the cloud voiceprint data memory to be composed of an IP communication module, adata storage module and a data processing module; and S4, periodically performing feature extraction, fault diagnosis and threshold correction on the voiceprint data stored in the disk by adopting anequipment health intelligent manager. According to the invention, the problems of difficult deployment of acquisition nodes, unstable work of a data server, slow fault diagnosis speed, low precision,non-adjustable fault diagnosis threshold and the like in the existing power equipment health monitoring technology are solved.

The invention discloses a doubly salient electro-magnetic motor converter power tube and winding open-circuit fault diagnosis method, and relates to the field of doubly salient electro-magnetic motors. And the neutral point voltage of the armature winding of the electro-magnetic doubly salient motor is compared with half of the bus voltage, open-circuit fault diagnosis is carried out on the power tube and the armature winding in the current operation state, the implementation method is simple and accurate, the fault diagnosis speed is high, the diagnosis cost is low, and the fault diagnosis accuracy is high. And the stability of the whole driving system is improved.

The invention relates to a current-limiting blockout device and method of a DC power distribution network. The device is composed of a current-limiting blockout loop (1) and a pre-charging circuit (2). The fault current-limiting blockout loop (1) is composed of a first capacitor (C), a first lightning arrester (Z), a first power electronic switch device (S1), a second power electronic switch device (S2), a third power electronic switch device (S3), a fourth power electronic switch device (S4) and a first current-limiting inductor (L). Thus, a fault current in the DC power distribution networkcan be limited and blocked rapidly, and impact of the fault current on a power supply and loads is greatly reduced in the DC power distribution network.

Embodiments of the invention provide a switch cabinet arc light protection method and device. The method comprises the steps that arc light of a switch cabinet is collected through an avalanche photodiode, the arc light is amplified and converted into a voltage signal, and the voltage signal is sent to a signal processing device; the signal processing device is used for judging whether the voltagesignal is larger than an early warning threshold value and a protection threshold value or not separately; if the voltage signal is larger than the early warning threshold value, an early warning signal is sent to a control center; if the voltage signal is larger than the early warning threshold value and the protection threshold value, a tripping signal is sent to a switch of the switch cabinet;and the signal processing device sends an alarm signal to the control center according to the condition that the voltage signal is larger than the early warning threshold value and the protection threshold value. According to the embodiments of the invention, the early warning threshold value and the protection threshold value participate in action logic judgment to serve as the locking conditionfor judging the switch cabinet fault, so that the fault judgment speed is high, the accuracy is high, and the operation safety of the switch cabinet is improved.

The invention discloses an unmanned aerial vehicle actuating mechanism fault diagnosis method based on extended Kalman filtering. The extended Kalman filtering technology is adopted to introduce the state of an actuating mechanism into a state vector of a filter, and only one filter can be used for monitoring all health states of one actuating mechanism, so that the method has the advantages of small calculated amount and high fault diagnosis speed. According to the unmanned aerial vehicle actuating mechanism fault diagnosis method based on extended Kalman filtering, three fault types of jamming, swinging and proportionality coefficient of the actuating mechanism can be comprehensively monitored, and the unmanned aerial vehicle actuating mechanism fault diagnosis method can be suitable fora flight control system which is limited in operational capability and requires rapid diagnosis and determination of the fault type of the unmanned aerial vehicle actuating mechanism.

The invention provides a wiring-free centralized control type distribution automation terminal and a system thereof. The terminal comprises a terminal central processing unit and a plurality of powerdistribution terminal subunits, wherein the terminal central processing unit is composed of a first power supply module, a first anti-surge protection module, a first EMC filtering module, a first central processing unit, a first Ethernet module and a WIFI module, the plurality of power distribution terminal subunits are used for collecting electrical signals of power distribution equipment, and the terminal central processing unit communicates with the plurality of power distribution terminal subunits through the WIFI module. The system provided by the invention comprises the power distribution automation terminal. The terminal is simple in structure, reasonable in design, free of wiring, and capable of rapidly positioning faults and being replaced in an electrified mode, and can guarantee the power supply continuity and reliability of a power distribution network so as to meet the requirements of an intelligent power grid.

The invention discloses an LLC resonant converter open-circuit fault diagnosis method based on resonant capacitor voltage, and the method comprises the steps: setting a reasonable threshold value according to the amplitude of the resonant capacitor voltage of an LLC resonant converter under a normal working condition, sampling the resonant capacitor voltage after a fault, and comparing the sampledresonant capacitor voltage with the set threshold value, thereby achieving the fault diagnosis; then, through phase shift control between bridge arms, realizing the fault positioning. The LLC resonant converter open-circuit fault diagnosis method provided by the invention is high in diagnosis speed, low in error diagnosis rate and high in robustness, and has important significance for ensuring the uninterrupted operation of the LLC resonant converter under the condition of an open-circuit fault.

The invention provides a real-time fault diagnosis method and system based on a sequential random forest. The method comprises: obtaining a to-be-detected residual signal of a to-be-diagnosed nonlinear system; extracting a time-frequency feature vector of the residual signal to be measured based on wavelet packet decomposition; substituting the time-frequency feature vector into a trained random forest fault separator, and performing sequential probability ratio test on the to-be-diagnosed nonlinear system to obtain target fault information, wherein the target fault information comprises a target fault type and target fault occurrence time; and substituting the time-frequency feature vector and the target fault type into a trained regression random forest fault identifier to obtain fault size information corresponding to the target fault type. The technical problems that in the prior art, real-time fault diagnosis cannot be achieved, and the missed diagnosis rate and the misdiagnosis rate are high are solved.

The invention discloses a power grid fault diagnosis method based on an equipment fault probability. The method comprises the steps: collecting historical operation data of relay protection and circuit breakers through real-time sensing of power equipment, and carrying out statistics of the relay protection and circuit breaker fault probabilities; collecting the number of relay protection and thecircuit breakers and configuration parameters between the relay protection and the circuit breakers from a power grid fault information system; collecting actual action states of the relay protectionand the circuit breakers and a power grid element state from a power grid dispatching automatic control system; constructing a power grid fault diagnosis multi-objective optimization model based on the fault probabilities of the relay protection and the circuit breakers and the acquired data by taking a minimum difference degree and a minimum evaluation risk of an actual action state and an expected action state of the relay protection and the circuit breakers as objectives; linearizing the optimization model to obtain a linear optimization model; and solving the linear optimization model by using a fuzzy optimization method. In the invention, a more accurate and rapid fault diagnosis result is obtained through solving the multi-objective optimization model.