38results about How to "Avoid secondary failure" patented technology

The invention discloses an open-circuit fault diagnosis method for switch tubes of a single-phase cascaded H-bridge rectifier. According to a system switch control signal and alternating-current sidecurrent polarity, switch functions under normal operation and different switch tube faults are calculated; and an output current calculation model and a state estimation model of a single-phase cascaded H-bridge rectifier module are obtained according to circuit topology of the cascaded H-bridge rectifier, and a calculated value and an estimated value of an output current are obtained. Based on characteristics that fault features of current residuals of different modules are separated and different fault diagnosis variables are mutually independent, any faulted switch tube can be positioned bycomparing the diagnosis variables with a self-adaptive detection threshold value. According to the method, the real-time diagnosis of the single-phase cascaded H-bridge rectifier in one or more switch tube fault states in an on-line real-time system can be realized, and the influence of network voltage fluctuation, load variation and operation condition change of the single-phase cascaded H-bridge rectifier is avoided; and moreover, the diagnosis time is short, the faults can be isolated in time, and the occurrence of secondary faults of the system is avoided.

The invention discloses a cascaded H-bridge converter fault diagnosis method based on a voltage residual. The method comprises the following steps of step1, according to a system switch control signaland an alternating current side current polarity, acquiring switch functions under a normal condition and different switch tube faults; step2, obtaining a single-phase cascaded H-bridge converter input voltage calculation model and a state estimation model of a corresponding module; step3, obtaining theoretical analysis values of a voltage residual under the different faults; and step4, accordingto the theoretical analysis value of the voltage residual, designing two types of counters to obtain a maximum positioning fault module, and further determining the fault switch tube through combining a switch signal. The method can be integrated into a controller, real-time performance is good, and real-time diagnosis of the single-phase cascaded H-bridge converter fault module and an open-circuit fault switch is realized.

The invention belongs to the technical field of power facilities and particularly relates to a fireproof power cable trench. The fireproof power cable trench comprises multiple trench bodies; each trench body comprises a bottom plate, side baffles and a cover plate; one accommodating cavity and multiple discharge ports are arranged in the side baffles and on the cover plate; the discharge ports are located at the inner side of the cable trench; the accommodating cavity and the multiple discharge ports are communicated; the accommodating cavity is internally provided with a fireproof material;and the discharge port is provided with a plugging mechanism. Through improving the structure of the trench body, the accommodating cavity with the fireproof material is arranged in the side baffles and the cover plate, self extinguishing is carried out while waiting for rescue, and secondary fault of a power device is avoided.

The invention discloses a three-phase fault-tolerant inverter circuit and a control method thereof. The three-phase fault-tolerant inverter circuit comprises a direct current power supply and an inverter bridge, the upper bridge arm of a first inverter bridge arm is connected with a high-speed fuse F1 while the lower bridge arm is connected with a high-speed fuse F4, the upper bridge arm of a second inverter bridge arm is connected with a high-speed fuse F3 while the lower bridge arm is connected with a high-speed fuse F6, and the upper bridge arm of a third inverter bridge arm is connected with a high-speed fuse F5 while the lower bridge arm is connected with a high-speed fuse F2; an auxiliary inverter circuit is connected between the direct current power supply and the inverter bridge and is composed of an auxiliary upper bridge arm insulated gate bipolar transistor Q7, an auxiliary lower bridge arm insulated gate bipolar transistor A8, an auxiliary first inverter bridge arm insulated gate bipolar transistor S1, an auxiliary second inverter bridge arm insulated gate bipolar transistor S2, an auxiliary third inverter bridge arm insulated gate bipolar transistor S3 and single-phase bridge rectifiers Z1, Z2 and Z3. The three-phase fault-tolerant inverter circuit and the control method thereof realize to isolate the fault of the bridge arm with short circuit or open circuit fault and have good fault-tolerant running function.

The invention provides a fault processing method of a traction driving system and the traction driving system. The traction driving system comprises a motor controller and a motor, and the method comprises the steps of obtaining fault state information of the traction driving system; obtaining a direct current end bus voltage of the motor controller; determining whether the motor enters a short-circuit mode or an idling mode based on the direct current end bus voltage and the fault state information; when it is determined that the motor enters the short-circuit mode, obtaining the state information of all power switch devices in the motor controller, and the state information of the power switch devices being used for reflecting whether each power switch device breaks down or not; and according to the state information of the power switch devices, controlling the power switch devices to execute corresponding operations, so that the motor works in the short-circuit mode. When the traction driving system breaks down, the motor can be in a safe state.

The invention discloses an open-circuit fault diagnosis method for a dual-active-bridge DCDC converter. The method specifically comprises the following steps of: calculating the switching function of two H bridges of the dual-active-bridge DC-DC converter according to a system driving pulse signal and the polarity of primary side inductive current; calculating an inductive current state estimation model of the dual-active-bridge DC-DC converter according to the circuit topology and the working principle of the dual-active-bridge DC-DC converter; and designing a fault diagnosis algorithm according to inter-bridge-arm voltage characteristics and current residual characteristics under the fault. According to the method of the invention, monitoring of the working state of the dual-active-bridge DC-DC converter and rapid and accurate diagnosis under different switching tube faults are realized, and a new diagnosis idea is provided for the fault diagnosis technology of the dual-active-bridge DC-DC converter.

The invention relates to a fault diagnosis method for a medium-voltage modular multilevel converter (MMC), which belongs to the field of power electronics, and comprises the following steps of: constructing a data set by using the collected capacitor voltage values of each sub-module and the current values of each bridge arm of the MMC, wherein the data set comprises normal operation state data and fault operation state data of sub-modules of the MMC; carrying out one-hot coding on the sample set according to the operation state of the modular multilevel converter to obtain a coding vector as a class label; performing parameter training on the training set by adopting a neural network and based on a BP back propagation algorithm to obtain a modular multilevel converter fault diagnosis model; and inputting the test set into an MMC fault diagnosis model, performing open-circuit fault diagnosis on each sub-module of the modular multilevel converter, and obtaining a fault type through matching with a class label. New devices such as sensors do not need to be introduced, and the system cost and complexity are not increased.

The invention discloses an electricity meter fault studying and judging method, device and equipment and a readable storage medium. The method comprises the steps of obtaining historical fault information of each electricity meter and fault information of a current fault electricity meter; determining a fault state code corresponding to each piece of fault information in the historical fault information; the types of fault state transition groups in the historical fault information and the number of the fault state transition groups are counted, and a fault state transition matrix is generated according to a statistical result; determining a target fault state code corresponding to the fault information of the current fault ammeter according to the fault information of the current fault ammeter; and according to the fault state transition matrix and the target fault state code, determining a fault research and judgment result of the current fault ammeter. According to the fault research and judgment result, the operation and maintenance personnel inspect the possible secondary fault problem in advance to avoid the secondary fault, or during the secondary fault inspection, the fault type with the high probability is preferentially detected to improve the fault inspection efficiency during maintenance.

The invention discloses a two-phase short-circuit fault locating and fault-tolerant operation controlling method for a brushless DC motor, comprising the steps of: 1.acquiring and transmitting three-phase current data; 2. analyzing and processing the three-phase current data and locating two-phase short-circuit fault of the brushless DC motor; 3.using a microprocessor module to perform four-step commutation and fault-tolerant operation control on the brushless DC motor according to the two-phase short-circuit fault locating result. The method has the advantages of simple steps, convenient implementation and high accuracy, and can carry out fault locating in a short time. The fault-tolerant operation controlling method can ensure that the brushless DC motor still operates stably and reliably after the two-phase short-circuit fault of a winding, and effectively improves the reliability and stability of the brushless DC motor system. The fault-tolerant operation controlling method has excellent practicality and good effects, and easy to popularize.

The invention provides a high-power four-quadrant converter fault-tolerant control method based on predictive control. The method comprises the following steps: acquiring converter parameter data after a fault bridge arm and a multiplexing bridge arm are connected through a bidirectional thyristor; blocking the switching signal of the fault bridge arm, and recombining the switching state of the converter according to the obtained parameter data; traversing all combined switch states, and predicting a system state quantity at a certain moment in the future; taking the minimum weighted sum of the network side cost function and the machine side cost function as a target to obtain an optimal combined switch state; performing converter control according to the optimal combined switch state. According to the method, the phenomenon of capacitor voltage unbalance aggravation in a traditional solution is overcome, the problems of secondary faults and control precision reduction caused by the phenomenon are avoided, continuous operation of a converter system under the fault condition is fully guaranteed under the condition that the degree of freedom of the switching state is not limited, and the reliability and the stability of the electric drive system are better improved.

The invention discloses an open-circuit fault diagnosis method and device, a motor controller and a computer readable storage medium. The method comprises the steps of determining three-phase reference current values, and acquiring three-phase actual current values; for each phase in the three phases, calculating a difference value between the phase actual current value and the phase reference current value; and judging whether a power tube open-circuit fault occurs or not according to the difference value. By adopting the scheme of the invention, open-circuit fault diagnosis is carried out based on the difference value between the reference current and the actual current, the open-circuit fault diagnosis time is shortened on the premise of not adding an additional sensor, the diagnosis result has relatively high reliability, and a secondary fault caused by a power switch tube fault of a vehicle motor system can be prevented.

The invention relates to an indoor waterproof leakage monitoring insulating top shell device which is technically characterized by comprising a waterproof leakage monitoring insulating top shell and a water guide supporting device installed at the lower end of the waterproof leakage monitoring insulating top shell. The waterproof leakage monitoring insulating top shell is made of a waterproof leakage monitoring insulating plate with the high middle and the two low sides, and water collecting grooves are formed in the lower edges of the two sides of the waterproof leakage monitoring insulating plate; and a drainage hole is formed in the water collecting groove and is used for draining water in the water collecting groove through the water guide supporting device. The water collecting groove is formed in the lower edge of the waterproof leakage monitoring insulation top shell, water in the water collecting groove is discharged through the water guiding supporting device at the bottom, and the functions of water prevention, water leakage monitoring, water leakage guiding, electrical insulation and isolation and the like are achieved; and meanwhile, the moisture-sensitive ink layer with uniform net-shaped patterns is arranged on the waterproof leakage-monitoring insulating top shell, so that maintenance personnel can find the water dripping condition and deal with the water dripping problem in time, and normal operation of the high-voltage electrical equipment is ensured.

The invention relates to an intelligent ore drawing device of an ore leaking trolley. The ore drawing device is mainly composed of an intelligent ore drawing device module input control contactor of the ore leaking trolley, a belt ore overflowing sensor device, a belt slipping sensor device and a belt hopper ore overflowing sensor device 25. According to the belt hopper ore overflowing sensor device, when the hopper ore reaches the maximum limiting capacity, the module receives data, the vibration machine vibrates, ore loosening is conducted, and the hopper ore overflowing phenomenon is prevented. The stock bin liquid level sensor monitors and sets the operation time and the interval time of the vibration motor according to the actual condition of the moisture content of the iron ore concentrate powder, and indirect ore loosening can be achieved to avoid large-area ore accumulation. The belt deviation sensor device monitors the running condition of the conveying belt in real time, the function of automatic alarming and line stopping is achieved when deviation occurs, and maintainers are prompted that the conveying belt production line is abnormal and needs to be repaired, maintained and corrected. The belt ore overflowing sensor device monitors the operation condition of ores above the belt all the time, and automatically alarms and stops the line when the ores are accumulated, so that large-area accumulation of the ores is avoided, and the secondary fault that electrical elements are damaged due to overload operation of a motor is avoided.

The embodiment of the invention discloses a data transmission method and device, equipment and a storage medium, and the method comprises the steps: responding to the failure of first real-time data transmission, and storing the first real-time data; retransmitting the first real-time data according to a specific period; in response to successful retransmission of the first real-time data, determining a real-time transmission task according to a preset rate threshold; the real-time transmission task at least comprises transmission of second real-time data; the second real-time data is acquired at the current time point.

The invention relates to the field of substation tool placement, in particular to a tool management system for preventing tools from missing, the tool management system comprises a cabinet body placed in a substation, a plurality of tools is placed in the cabinet body, each tool is fixedly connected with a UWB positioning tag, and positioning base stations are arranged in the substation. The number of the positioning base stations is at least four, the positioning base stations are uniformly arranged around the cabinet body, the positioning base stations are connected with a position resolving server, the position resolving server is connected with each positioning base station, and the position resolving server is connected with an alarm device. According to the tool management system, the UWB positioning tags are fixed on the tools, and the UWB positioning tags are used for tracking and positioning the positions of the tools, so that the purpose of avoiding secondary faults of electrical equipment caused by the fact that maintenance personnel omit the tools on a working plane is achieved.