52 results about "Reliability block diagram" patented technology

The invention provides a method for updating an electronic product reliability prediction model complying with exponential distribution, which comprises the following steps of: 1, analyzing a use region of products; 2, acquiring calendar year meteorological information of each province and city in the use region, and calculating a year average value of temperature stress and humidity stress in each region; 3, respectively constructing a temperature and humidity probability density distribution function, and solving a year average value of temperature stress and humidity stress in the use region; 4, analyzing each stress borne in a product use process; 5, selecting a reliability prediction manual, and calculating an element work failure rate according to a stress analysis model; 6, drawinga product mission reliability block diagram and compressively calculating a product work failure rate; 7, carrying out an acceleration life test and recording test data; 8, product mean life to failure under a test condition and work failure rate under a normal work condition; and 9, comparing product work failure rates obtained by reliability prediction and the accelerated life test, calculatingerrors generated by the humidity stress, and offering a reliability prediction correction model.

The invention discloses a method for realizing the reliability allocation for a product with a balanced life. The method comprises steps that through the product function and structure analysis, the subfunctions and a subcomponent database of a product are built; based on the energy transfer, conversion and branching relation, a reliability block diagram of a multi-subcomponent series-parallel connection structure is built for each subfunction; the reliability block diagram is analyzed, two objective optimization models which has the maximum reliability of the subfunctions and the minimum reliability variance of a series subsystem are built, and a multi-objective optimization evolutionary algorithm is used for solving; and the reliability of the product subcomponents selects the reliability mean value of all the subfunction operation, the subcomponents with the similar reliabilities are clustered into a module, so the product reliability allocation and module planning scheme is obtained. By aiming at the problem that the whole reliability of the product is lowered due to unbalanced reliabilities of the subcomponents during the product design, a model is built on the basis of an energy reliability block diagram, a method for realizing component reliability balance and optimized product reliability allocation is proposed, so the whole reliability allocation scheme of the product is obtained.

The invention discloses a ship alternative-current zone power distribution network system and a reliability analysis method thereof. The system is characterized in that an entire ship is divided into multiple zones, wherein the power supply of loads in one or more zones is guaranteed by one power generator unit, each power generator unit consists of a power generator, a power distribution panel, a circuit breaker and a load, an electric power bus passes through a watertight cabin from two sides of a cabin so as to join four power generators on the head and the end of the ship, and finally a circular power supply network is formed. The method comprises steps of drawing a corresponding reliability diagram according to a structure of the power distribution network; performing equivalence for local relatively-independent structures in serial connection or in parallel connection, and simplifying the reliability diagram; establishing different connection matrixes between one load point j and different power supplies; obtaining a minimal route according to the connection matrix so as to obtain a minimal cut set; eliminating the influence of a shared device on the calculation result by utilizing a session description protocol (SDP) method; and calculating a reliability parameter of the load point and a systematic reliability parameter.

An SCD-based relay protection online reliability evaluation system in the field of electrical power systems comprises a net communication module, a man-machine interface module, a model analyzing module, a data processing module and a reliability evaluation module; an SCD file is analyzed to acquire a construction scheme of a protection system and primary elements, and the construction scheme is converted into an RBD (Reliability Block Diagram); SV, GOOSE and MMS messages reflecting the running state of the protection system are processed into intermediate data needed by reliability calculation, and static and online reliability evaluation analysis on the protection system is finished based on a reliability analysis theory, the RBD and a reliability algorithm. Static and online reliability evaluation on the protection system of an intelligent substation is realized, hidden danger of the relay protection system can be effectively found, a foundation is laid for reliability analysis-based state evaluation, the availability ratio of the relay protection system is improved, and reliable guarantee is provided for safe operation of a power grid.

The invention discloses a reliability assessment scheme for a secondary system of an intelligent substation. A reliability evaluation model for the secondary system of the intelligent substation is established by utilizing reliability block diagram, connection matrix and minimal path set technologies; overall system reliability is calculated based on the development of device reliability evaluation, component importance analysis is introduced into the secondary system, and component importance evaluation is performed on the secondary system of the intelligent substation by utilizing probability importance and key importance; and according to reliability assessment results, weak links influencing the reliability of the system are analyzed, the reliability of the system is improved by adopting system structure optimization and equipment redundancy measures, and the new needs of the intelligent substation are fully satisfied. The scheme provided by the invention is applied to the reliability assessment of the secondary system of the intelligent substation and a power system.

The invention discloses a ship power station reliability real-time online evaluating system and evaluating method. The system comprises a ship power station system reliability model database storage subsystem, an information collection subsystem and an evaluating subsystem. The ship power station reliability real-time online evaluating system is used for storing a basic principle of a ship power station system reliability model, the information collection subsystem is used for collecting and monitoring ship power station working condition parameter information under the current ship power station running condition in real time, and the evaluating subsystem is used for calling a corresponding reliability model in the system reliability model database subsystem to evaluate the reliability of a current ship power station in real time according to the ship power station working condition parameters which are monitored in real time. According to the system and method, reliability block diagrams and corresponding reliability mathematical models can be built under different working conditions of a ship power station, the corresponding reliability models can be called by monitoring the working condition situations of the ship power station in real time according to the current working condition situation of the ship power station, and the reliability of the ship power station under the current working condition situation is online evaluated in real time.

The invention discloses an overhaul period optimization method for an intelligent substation protection system, and the method comprises the steps: employing a Weibull distribution function and an improvement factor which represents the influence of planned maintenance on an equipment failure rate, and building an equipment failure rate model which considers the aging of equipment and incomplete planned maintenance; establishing a fault rate model of the intelligent substation line protection system by using the reliability block diagram; adopting different planned maintenance periods in the stable operation period and the loss period of the line protection system; constructing an annual average operation cost model of the intelligent substation line protection system, considering the sampling trip-out modes of the direct mining direct tripping mode, the direct mining network tripping mode, the network mining network tripping mode, the single line protection configuration, the double line protection configuration mode and the maintenance cost of different maintenance types, and solving to obtain the optimal planned maintenance period of each of the two stages when the annual average operation cost is minimum. The influence of equipment aging, maintenance type, protection configuration and sampling tripping mode is considered, and the maintenance cost can be effectively reducedwhile the reliability of the protection system is improved.

The invention discloses a method for analyzing the reliability of an electrical control and drive system of a heavy-duty numerical control machine tool. The method comprises the steps: firstly dividing a system into subsystems; secondly finding out a subsystem which frequently has faults, drawing a reliability block diagram of the subsystem, and converting the reliability block diagram into a Bayesian network, thereby calculating the fuzzy probability of the subsystem in different states, and achieving the quantification and processing of the uncertainty of the system.

The invention discloses a method for acquiring the reliability of a direct-current power transmission system based on parameter matrix, comprising the following steps: determining a system reliability block diagram according to the topology and the running status of a direct-current power transmission system; extracting running statistical information of each component and calculating to obtain reliability parameters of the component, and establishing subsystem reliability models according to the mode of component connection; combining the subsystem reliability models by a parameter matrix method and calculating to obtain a direct-current power transmission system reliability model; and selecting reliability indexes, and calculating the reliability indexes on the basis of the system reliability model, so as to achieve the purpose of direct-current power transmission system reliability evaluation.

The invention discloses a risk assessment method of an intelligent transformer substation protecting system. A Markov process is utilized. Data statistics is performed according to reliability of each secondary device, thereby calculating steady-state availability, stable-state false operation probability and stable-state operate-on-command failure probability. A reliability block diagram method is utilized for calculating the stable-state availability, the stable-state false operation probability and the stable-state operate-on-command failure probability of each protecting system. For aiming at a certain false operation or operation-on-command failure, a fault frequency of a corresponding main wiring and a relative value are calculated. A load loss amount is obtained. The product of the protected stable-state false operation probability or the operate-on-command failure probability, the load loss amount and the relative value of the fault frequency of the main wiring are defined as the protecting risk. The risk of each protecting system in abnormity, the risk in operation stoppage failure and the ratios of the two risks in a total-station comprehensive risk are quantitatively obtained. Through sequencing, the influence degree of the risk caused by each protecting failure is obtained. According to the risk assessment method, through calculating the operation risk of the protecting failure, the influence of the operation risk to the intelligent transformer substation protecting system can be quantitatively evaluated.

The invention discloses a reliability fuzzy prediction method based on hierarchical division of a welding robot system. The method comprises the following steps: firstly, the appointed hierarchical division is performed for the welding robot system to determine subsystems of the robot system and modules and parts included in all the subsystems; a reliability block diagram of the robot system is built; a reliability mathematical model of the system is built; the total failure rate of the subsystems is determined and controlled; grading coefficients of all the subsystems are determined; the failure rates of other unknown subsystems are determined according to the failure rates of the known subsystems and the grading coefficients of the subsystems; and the total failure rate, namely the MTBF value of the welding robot system can be obtained according to the reliability mathematical model of the welding robot system. The method has no need to perform the reliability prediction for all parts of the welding robot system, and meanwhile, adopts the fuzzy theory and eliminates the defects in a traditional expert grading method to provide new thoughts for reliability prediction of complex electromechanical systems.

The invention discloses a component failure source-based MMC reliability analysis method. Taking a half-bridge submodule MMC as an example, reliability analysis is carried out from components to a system through electric stress obtained from simulation. The effects of temperature and voltage on the system-level reliability of the MMC under normal operating conditions and extreme conditions are obtained through a reliability block diagram and hot standby redundancy modes according to a component-level reliability failure factor to improve an existing reliability analysis method. The method fromcomponent-level failure rate evaluation to system-level reliability analysis and the analysis process for a failure source can be applied to reliability analysis of the other systems and can be usedas references of balancing the economy and the reliability in practical engineering, and the system reliability design is optimized from the component failure rate.

The invention discloses a conversion system and method for converting an architecture model into a reliability block diagram. The system comprises a user interface module, a model configuration module, a model analysis module, a topological structure module, a block diagram layout module, a model management module and a data management module. The method includes the steps of building the architecture model, configuring the architecture model, analyzing the architecture model, generating a reliability block diagram tree, generating a component model connection relation and drawing the reliability block diagram to smoothly convert the architecture model into the reliability block diagram. The method can be implemented through a computer program, the configured architecture model is automatically converted into the reliability block diagram, and labor is saved. The reliability block diagram obtained after conversion is organically combined with the architecture model, when the architecture model is modified, the reliability block diagram can also be synchronously updated, and the problem that when the architecture model needs to be modified frequently according to needs, the corresponding reliability block diagram also needs to be manually and frequently modified is solved.

The invention relates to a system reliability block diagram computer automatic identification and rapid calculation method. The method comprises the following steps: inserting a parallel relationshipnode between a parallel component and a common import component in a system reliability block diagram, respectively setting a union-union central component and a voting component as a union-union relationship node and a voting relationship node, and setting other components in the system reliability block diagram as component nodes; generating a system reliability network according to the connection relationship between the nodes, and obtaining an output reliability value of the system reliability network according to a preset calculation rule, wherein the output reliability value is a reliability value of the system reliability block diagram. By using the method, the corresponding system reliability network can be generated; the whole process is simple and can be completely and automatically realized by a computer, the defects that the manual calculation efficiency is low and the method is not suitable for a complex system are avoided, and the problem that the Monte Carlo simulation method cannot accurately calculate the reliability value of the system is also solved.

The invention provides a method for efficiently solving a reliability block diagram model based on a structure identification method and a binary decision diagram model. The method aims at improving the modeling capability and the calculation efficiency of the reliability block diagram model of the large-scale complex system. The method comprises the following steps: firstly, identifying basic structures in a reliability block diagram model, such as series connection, parallel connection, voting and sum connection, replacing the basic structures with a complex unit, recursively calling the method, and finally forming a simple reliability block diagram model with a hierarchical structure; secondly, traversing the hierarchical reliability block diagram model from top to bottom until the modules at the bottommost layer, converting the modules into corresponding binary decision diagram models according to the structure types, and performing upward backtracking and layer-by-layer conversion to finally form a hierarchical binary decision diagram model; and finally, evaluating the reliability level of the complex system according to the constructed binary decision diagram model.

The invention discloses a roll-control electronic module storage reliability assessment method integrating a process and a reliability block diagram. The method comprises the steps that firstly, a roll-control electronic module function simulation model is established, a sensitivity analyzing method is utilized to determine bottom-layer key components and devices affecting output characteristics of a roll-control electronic module by combining with investigation results of manufacturers; secondly, initial distribution of output characteristic parameters is analyzed by combining with a failuremode and a failure mechanism, storage of degeneration test measured data is promoted, and storage degeneration data of the bottom-layer key components and devices having distribution characteristics is obtained; finally, by combining with a failure threshold value and the established roll-control electronic module storage reliability block diagram, the roll-control electronic module storage reliability is obtained. The problem is solved that the accuracy of roll-control electronic module storage reliability assessment is low under the small sub-sample problem, and a new thought is provided forroll-control electronic module storage reliability assessment.

The invention discloses a memory, and a safety instrument system SIL verification method, system and device. The method comprises the following steps: setting a safety instrument function SIF loop used for constructing a reliability block diagram into a sensing unit, a logic controller unit and an execution unit; according to the failure data of each element in the SIF loop, respectively calculating a safety failure fraction SFF and a maximum fault margin HFT of each unit, and obtaining a structure constraint level of the SIF loop; and when the three units are respectively subjected to modeling calculation, calculating the common cause failure of the undetectable dangerous failure part of the element according to the regular detection time interval of the element and the corresponding PTC (Positive Temperature Coefficient) of the element. When the common cause failure of the undetectable dangerous failure part is calculated, compared with the prior art in which the influence caused by the change of the test period is not considered, the method can effectively improve the accuracy of the result of calculating the average failure probability by the SIF loop.