47results about How to "Avoid fault misjudgment" patented technology

The invention provides a convergence detecting method and system for a convergence box. By means of verification of current values of adjacent input ends or similar input ends, the fault false alarm rate of the convergence box in a photovoltaic array is reduced. The invention further provides a solar power station.

The present application discloses a fault detection method, device, device, and computer-readable storage medium for a distributed storage system. The method includes: according to the storage pool type of the distributed storage system, using corresponding calculation rules to determine the fault threshold value; Obtain the number of times that each node in the distributed storage system is reported as being in an abnormal state; and determine the fault condition of the distributed storage system according to the number of reports and the fault threshold value. It can be seen that the fault threshold value in this method is determined according to the storage pool type of the storage system and using the corresponding calculation rules. Therefore, the fault condition of the distributed storage system is determined according to the number of reports and the fault threshold value. It can avoid misjudgment of faults caused by faulty nodes in the back-end network misreporting abnormalities of other nodes, improve the accuracy of fault detection in the distributed storage system, and relatively guarantee the normal use of the entire distributed storage system.

The invention discloses a method and system for locating a distribution network fault section based on ground fault transfer. When an arc ground fault occurs in a neutral point non-effectively grounded system, the active grounding of the faulty phase bus can effectively suppress the arc overvoltage and eliminate the arc. Fault. At the same time, the zero-mode current polarity of the upstream measuring point of the fault point is opposite before and after the fault transfer, and the zero-mode current polarity of the downstream measuring point of the fault point is the same, which can identify the fault section. S-transform the zero-mode current of each measuring point after each feeder is grounded twice, determine the arrival time of the first wave head of the fault traveling wave according to the principle of modulus maximum at the Nyquist frequency, and calculate the corresponding phase at this time, Then the polarity coefficient of each measuring point is obtained; the section coefficient is constructed by the product of the polarity coefficients of the measuring points at both ends of the section to realize the location of the fault section. This method can avoid misjudgment of faults caused by asynchronous data collection, and is not affected by the reverse polarity of zero-sequence CT, which improves the reliability of fault section location in distribution network.

The invention discloses a tempering monitoring method and system, relating to the field of engines, comprising the following steps: the engine runs normally, acquiring the position of the throttle valve, the intake pressure and the intake air temperature; respectively judging the change rate of the throttle valve position and the intake air pressure Whether the rate of change and the rate of change of intake air temperature are within the corresponding preset change rate range; if both, the ignition advance angle is obtained; otherwise, restore the preset ignition advance angle; determine whether the ignition advance angle is within the preset ignition advance angle range If the ignition advance angle is delayed, correct the ignition energy; otherwise, confirm the engine failure, limit the torque and issue a warning. It can be seen that the present invention judges whether tempering occurs by monitoring the rate of change of throttle position, intake pressure and intake air temperature, and distinguishes normal changes at the same time to avoid misjudgment of faults. The fault indicator light and so on remind timely maintenance and inspection to avoid damage to engine parts due to backfire.

The invention provides a convergence detecting method and system for a convergence box. During zero value judgment, current values of adjacent input ends or similar input ends are utilized for mutual verification, during mean value judgment, the number of solar battery pack strings actually connected to the input ends of the convergence box of the grade are taken into consideration for mean value judgment, during high-value out-of-limit and low-value out-of-limit judgment, change rates of the current values of the adjacent input ends or the similar input ends are mutually verified, and the fault judgment accuracy of the convergence box in a photovoltaic array is improved. The invention further provides a solar power station.