Modularization-based power distribution system reliability evaluation method and system

Abstract

The invention discloses a modularization-based power distribution system reliability assessment method and system, and relates to the technical field of power distribution systems, and the method comprises the specific steps: obtaining a to-be-assessed power distribution system, and dividing the to-be-assessed power distribution system into a plurality of subsystems according to a preset rule; constructing a plurality of evaluation sub-models based on the power supply structures of the plurality of subsystems; based on the to-be-evaluated power distribution system, constructing a reliability evaluation model by using the plurality of evaluation sub-models; and obtaining reliability related parameters according to the to-be-evaluated power distribution system, and inputting the reliability related parameters into the reliability evaluation model to obtain the reliability of the to-be-evaluated power distribution system. Main equipment on a power supply link of the power distribution system is divided into different subsystems according to the close degree of coupling of the main equipment, a model is established in each subsystem according to the transfer relation of the power supply state, the complexity of the whole model is effectively reduced, the accuracy of state analysis is reserved, and the reliability of the whole model is improved. And the problem of excessive simplification possibly occurring when a series-parallel model is purely used is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution systems, and more particularly to a method and system for evaluating the reliability of a power distribution system based on modularization. Background Art

[0002] With the rapid development of information technology, data centers have become one of the indispensable infrastructures in modern society. Data centers not only store a large amount of data information, but also provide a variety of online services. Their stable operation is of great significance to the protection of social and economic activities. Therefore, the power supply reliability of data centers has become one of the key indicators to measure their service quality.

[0003] As a core component of a data center, the power distribution system is responsible for providing a continuous and stable power supply to key facilities such as servers and network equipment. However, due to the complex structure of the data center power distribution system and the large number of electronic components involved, how to accurately evaluate its power supply reliability has become a challenge. Traditional reliability assessment methods, such as the combination method (series-parallel method) and the state method (reliability diagram method, etc.), although they can provide certain guidance in theory, have obvious limitations in practical applications. For example, when the system is large in scale, the state method often leads to an analysis model that is too large and difficult to handle; and the simple series-parallel model cannot accurately reflect the complex operating state and conversion mechanism within the system.

[0004] In addition, in order to improve power supply reliability, modern data center power distribution systems usually adopt multi-level redundant designs, including but not limited to hot standby and cold standby solutions. Although this design improves the fault tolerance of the system, it also makes the reliability assessment of the system more complicated. Traditional reliability analysis methods are difficult to effectively cope with these new challenges, especially when multiple operating mode conversions and redundant configurations need to be considered. Therefore, how to provide an efficient and accurate data center power distribution system reliability assessment solution is an urgent problem that technicians in this field need to solve. Summary of the invention

[0005] In view of this, the present invention provides a modular-based distribution system reliability assessment method and system to overcome the above-mentioned defects.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A distribution system reliability assessment method based on modularization, the specific steps are:

[0008] Acquire a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules;

[0009] Building a plurality of evaluation sub-models based on the power supply structures of the plurality of sub-systems;

[0010] Based on the power distribution system to be evaluated, a reliability evaluation model is constructed using a plurality of evaluation sub-models;

[0011] Reliability-related parameters are obtained according to the power distribution system to be evaluated, and the reliability-related parameters are input into the reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

[0012] Optionally, the preset rule is set based on the degree of coupling between various devices in the power distribution system to be evaluated.

[0013] Optionally, the subsystem includes a high and low voltage power supply subsystem, an uninterruptible power supply subsystem and a load power supply subsystem.

[0014] Optionally, the steps of constructing the evaluation sub-model are:

[0015] Acquire historical data of each subsystem, and extract operation status change channels and fault data based on the historical data; the fault data includes operation status, fault occurrence probability and fault recovery probability;

[0016] The evaluation sub-model of each sub-system is constructed based on the operation status change channel and the fault data of each sub-system.

[0017] Optionally, the steps of constructing the reliability assessment model are:

[0018] Based on the power distribution system to be evaluated, a routing sequence and a combination relationship of each subsystem are obtained, wherein the combination relationship includes a series relationship and a parallel relationship;

[0019] Determine the combination mode of each evaluation sub-model according to the combination relationship of each sub-system;

[0020] The plurality of evaluation sub-models are combined and connected in the combination mode based on the routing sequence to obtain the reliability evaluation model.

[0021] Optionally, when the combination relationship of each subsystem is a series relationship, the expression of the combination mode of each evaluation submodel is:

[0022] R 系统 =R1×…×R n ;

[0023] In the formula, R n is the reliability of n subsystems.

[0024] Optionally, when the combination relationship of each subsystem is a parallel relationship, the expression of the combination mode of each evaluation submodel is:

[0025] R系统 ={1-[1-R] 2} n(n+1) / 2 ;

[0026] Where n is the number of subsystems.

[0027] A modular distribution system reliability assessment system, comprising:

[0028] A subsystem division module, used to obtain a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules;

[0029] A first model building module, used to build a plurality of evaluation sub-models based on the power supply structures of the plurality of sub-systems;

[0030] A second model building module is used to build a reliability evaluation model based on the power distribution system to be evaluated by using a plurality of evaluation sub-models;

[0031] An evaluation module is used to obtain reliability-related parameters according to the power distribution system to be evaluated, and input the reliability-related parameters into the reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

[0032] It can be seen from the above technical solutions that the present invention discloses a modular distribution system reliability assessment method and system, which has the following beneficial effects compared with the prior art:

[0033] 1. Simplify model complexity: By dividing the main equipment on the power supply link of the distribution system into different subsystems according to the degree of their coupling, a model is established within each subsystem based on the transfer relationship of the power supply state, which effectively reduces the complexity of the overall model. This not only retains the accuracy of the state analysis, but also avoids the problem of over-simplification that may occur when using only the series-parallel model;

[0034] 2. Improve flexibility and adaptability: Different subsystems are connected into a system overall model through series and parallel relationships. This design makes the model highly flexible. When the system structure changes, there is no need to rebuild the entire model like fault tree analysis. It is only necessary to adjust the affected subsystems and their connections. This not only greatly reduces the extra workload caused by system structure adjustments, but also improves the model's ability to handle complex fault conditions.

[0035] 3. Easy to code and automate: In the subsequent application promotion process, users only need to select the type of different subsystems, select the coupling method between different subsystems, and enter the necessary parameters, and the system can automatically calculate the reliability data of the distribution system. This feature not only improves the evaluation efficiency, but also enables non-professionals to easily use the tool to evaluate the reliability of the distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0037] Figure 1 A schematic diagram of the method provided by the present invention;

[0038] Figure 2 A schematic diagram of a state transition process model of a high and low voltage power supply system of a 2n oil-carrying machine provided by the present invention;

[0039] Figure 3 A schematic diagram of a state transition process model in a stand-alone operation mode of a UPS power supply provided by the present invention;

[0040] Figure 4 A schematic diagram of a state transition process model of a load power supply subsystem provided by the present invention;

[0041] Figure 5 A schematic diagram of power supply for a two-way power supply cabinet provided by the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] On the one hand, this embodiment discloses a method for evaluating the reliability of a power distribution system based on modularization. Figure 1 As shown, the specific steps are:

[0044] Step 1: Obtain a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules;

[0045] Step 2: construct multiple evaluation sub-models based on the power supply structure of multiple subsystems;

[0046] Step 3: Based on the power distribution system to be evaluated, a reliability evaluation model is constructed using multiple evaluation sub-models;

[0047] Step 4: Obtain reliability-related parameters based on the power distribution system to be evaluated, and input the reliability-related parameters into a reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

[0048] In one embodiment, the preset rule is set based on the degree of coupling between various devices in the power distribution system to be evaluated.

[0049] In one embodiment, the subsystem includes a high and low voltage power supply subsystem, an uninterruptible power supply subsystem and a load power supply subsystem.

[0050] Furthermore, taking the common power distribution system of current Class A data centers as an example, the power distribution system is divided into three subsystems: high and low voltage power supply subsystem (backup power supply), uninterruptible power supply subsystem, and load power supply subsystem according to the close degree of coupling of equipment connection relationship. In the process of model establishment, the reliability data of cables and busbars are not considered for the time being. It is assumed that the connection structures such as cables and busbars are reliable, and only the reliability of each node of the primary power supply line is considered to affect the overall reliability of the system. Among them, the reliability data of the mains input mainly depends on the power supply quality, so it is planned to be directly introduced as a parameter in the model without separate modeling.

[0051] In one embodiment, the steps of constructing the evaluation sub-model are:

[0052] Step 21: Obtain historical data of each subsystem, and extract operation status change channels and fault data based on the historical data; the fault data includes operation status, fault occurrence probability and fault recovery probability;

[0053] Step 22: construct an evaluation sub-model for each sub-system based on the operation status change channel and fault data of each sub-system.

[0054] In one embodiment, the steps for constructing the evaluation sub-model corresponding to the high and low voltage power supply sub-system (including oil-powered machine) are as follows:

[0055] In the normal state of the high and low voltage power supply system with oil generator, the oil generator is in cold standby and the connection is disconnected, and each mains supply its rear-end load, and the rear-end operates normally; when one mains is interrupted, the other mains carries all the rear-end loads through the connection, and the rear-end loads are still supplied with mains; when the two mains are interrupted at the same time, the oil generator starts and carries all the rear-end loads through the connection, and the rear-end loads are still supplied with power; when the oil generator backup time reaches the limit and the mains has not been restored, the output of the high and low voltage power supply subsystem will be interrupted; regardless of whether the mains supply status is normal, when an abnormal fault occurs in the power supply and distribution cabinet downstream of the connection cabinet, such as circuit breaker tripping, circuit breaker failure, etc., resulting in power interruption, the rear-end power supply output will be interrupted, and the load cannot be powered by the oil generator or other means.

[0056] exist Figure 2Among them, state 1 indicates that the high and low voltage power supply subsystem is in normal operation; state 2 indicates that one mains supply is interrupted and the other mains supply carries all loads; state 3 indicates that both mains supplies are interrupted and the oil generator output carries all loads; state 4 indicates that the oil generator power supply carries all loads; state 4 represents that the power supply output of the high and low voltage power supply subsystem is interrupted.

[0057] λ1 represents the probability of an external mains power interruption; μ1 represents the probability of restoration of the interrupted external mains power supply; λ2 represents the probability of an interruption in another mains power supply; μ2 represents the probability of restoration of another mains power supply; λ3 represents the probability of an output interruption of the oil generator; λ4 represents the probability of a failure in the downstream distribution cabinet.

[0058] It can be seen that the output of the high and low voltage power supply subsystem of the 2n oil-carrying machine is interrupted, that is, when entering the state, it can be entered by state or by state. Channel 1: The system directly enters state 4 from state 1, and the conversion relationship is related to the fault level of the equipment downstream of the connection. Channel 2: The system first enters state 2, then enters state 3, and finally enters state 4.

[0059] The probability of channel 1 is: P 1→4 =λ4P1;

[0060] The probability of channel 2 is: The probability of a single UPS entering state 4 from state 1 is P 1→2→3→4 =λ1λ2λ3P1;

[0061] When the system is running, the probability of system output interruption is:

[0062] Q = λ4P1 + λ1λ2λ3P1;

[0063] The reliability is:

[0064] R 高低压 =1-Q;

[0065] Substituting the probability of system output interruption into the equation, we can obtain:

[0066] R 高低压 =1-λ4P1+λ1λ2λ3P1.

[0067] In one embodiment, the steps of constructing the evaluation sub-model corresponding to the uninterruptible power supply sub-system are:

[0068] The UPS power supply equipment is in the rectification-inversion state under normal conditions. When the mains power is suddenly interrupted, the UPS power supply switches to the battery-inversion output mode. In the battery-inversion output mode, the UPS backup battery can support the IT equipment to continue to operate for a considerable period of time; when in the battery-inversion output state, after the front-end mains input is restored, the UPS power supply will return to the rectification-inversion output state; when the internal rectifier or inverter of the UPS power supply fails in the rectification-inversion output mode, it can be switched to the bypass output mode. In the bypass output state, the rear-end load is not protected, that is, a short-term interruption of the front-end mains power will cause the rear-end equipment to lose power and shut down.

[0069] Figure 3 This is a schematic diagram of the state transition process model in the UPS power supply stand-alone operation mode. Figure 3 In the figure, state 0 indicates that the UPS power supply is in the normal operation state of rectification-inversion, and the rear-end load is protected; state 1 indicates that the UPS power supply is in the battery-inversion operation state, and the rear-end load is protected; state 2 indicates that the UPS power supply is in the bypass operation state, and the rear-end load is not protected. λ5 indicates the probability of interruption of the front-end power supply of the UPS power supply, which is equivalent to the failure rate of the front-end distribution network; μ2 indicates the probability of restoration of the front-end power supply of the UPS power supply within the battery backup time, which is equivalent to the probability that the front-end distribution network is repaired within the battery backup time; λ6 indicates the probability that the front-end power supply of the UPS power supply cannot be restored within the battery backup time, which is equivalent to the probability that the front-end distribution network cannot be repaired within the battery backup time; λ7 indicates the probability of failure of the internal rectifier or inverter of the UPS power supply; μ3 indicates the probability of successful restart of the UPS power supply after manual repair.

[0070] The random transition probability matrix of UPS power supply single machine operation is:

[0071]

[0072] If the steady state probabilities of the three operating states are P0, P1, and P2 respectively, then:

[0073]

[0074] At the same time, P0+P1+P2=1;

[0075] The solution is that when t→∞, the probabilities of the three operating states under the limit state are:

[0076]

[0077]

[0078]

[0079] The UPS power supply equipment determines whether the system is available based on whether the back-end equipment is protected. The steady-state availability A and unavailability U of the system are:

[0080] A=P0+P1,U=P2;

[0081] Assume that the UPS power supply is running in the rectification-inversion state, i.e., state 0 in the initial state. Whether the parallel system is running reliably is evaluated by whether the UPS power supply backend equipment is powered off and down. Then the probability of reliable operation of the system includes [the probability of the system running in state 0] + [the probability of the system running in state 1] + [the probability of no mains interruption after directly transferring from state 0 to state 2 due to equipment failure]. Among them, [the probability of no mains interruption after directly transferring from state 0 to state 2 due to equipment failure] indicates that when the bypass operation state is in the case of equipment failure, the mains power is no longer adjusted and optimized by the UPS power supply and is directly supplied to the backend equipment. When the front end is running reliably with the mains power, the backend equipment is powered normally and still running, so it should be included in the reliability range. There are two channels for the UPS power supply equipment to enter state 2, namely channel 1: from state 0 to state 2, at which the probability of normal power supply of the backend equipment is the reliability of the front end reusing the power supply line; channel 2: from state 1 to state 2, at which time it means that the backup battery is exhausted, and the backend equipment enters state 2 and loses power and shuts down.

[0082] The probability of channel 1 occurring is P 0→2 =λ7P0;

[0083] The probability of channel 2 occurring is P 1→2 =λ6P1;

[0084] The failure rate of the front-end power supply line is λ5, and the probability of UPS power output interruption is:

[0085] Q 单机 =λ5λ7P0+λ6P1;

[0086] Further we can get:

[0087]

[0088] The reliability of normal power supply to back-end equipment when UPS is running alone is:

[0089]

[0090] In one embodiment, the steps of constructing the evaluation sub-model corresponding to the load power supply sub-system are:

[0091] Most of the load power supply subsystem equipment are dual power supply equipment. Under normal circumstances, the interruption of a single power supply of the load power supply subsystem will not affect the back-end load. The back-end load will only be interrupted when the dual power supplies are interrupted at the same time. Under normal circumstances, both power supplies from the UPS output downstream to the load are normal, and both power supplies of the back-end load have output; when a link in any of the links fails, resulting in an interruption of the power supply of the line, the other link is responsible for the output to ensure that the power supply of the back-end load is not interrupted; when both load supplies are interrupted, the back-end load power supply is interrupted. The two power inputs of the load power supply subsystem can be from the same source or different sources, and the supply form can be AC ​​power or U power, which is determined according to the cabinet (row head cabinet) level.

[0092] Figure 4 is the state transition process model of the load power supply subsystem. Assume that the inputs at the top of the cabinet are a and b respectively, and the failure probabilities of the front inputs are λ a , b ; State 1: Both ab and ab are powered normally. State 2: One ab is powered normally and the other is abnormal; State 3: Both ab and ab are powered abnormally. When the system enters state 3, the power supply to the back-end load is interrupted. λ8 represents the probability of a failure in one of the lines; μ4 represents the probability of power restoration after repair by personnel; λ9 represents the probability of another line failing; λ 10 Indicates the probability of failures occurring on both paths simultaneously.

[0093] When the system is running, the probability of system output interruption is:

[0094] Q=λ 10 P1+λ8λ9P1;

[0095] The probability of normal power supply R 负载供电 =1-Q=1-λ 10 P1-λ8λ9P1;

[0096] Where P1 is the probability that the load power supply subsystem operates normally.

[0097] In one embodiment, the steps of constructing the reliability assessment model are:

[0098] Based on the power distribution system to be evaluated, the routing sequence and combination relationship of each subsystem are obtained, and the combination relationship includes a series relationship and a parallel relationship;

[0099] Determine the combination mode of each evaluation sub-model according to the combination relationship of each sub-system;

[0100] Based on the routing sequence, multiple evaluation sub-models are combined and connected in a combination manner to obtain a reliability evaluation model.

[0101] In one embodiment, if there are n subsystems connected in series in the system, the reliability of the nth subsystem is R n The expression is:

[0102] R 系统 =R1×…×R n ;

[0103] In the formula, R n is the reliability of n subsystems.

[0104] In one embodiment, if there are n subsystems in parallel in the system, the reliability of the nth subsystem is R n , then the overall reliability of the parallel system is

[0105] R 系统 ={1-[1-R] 2} n(n+1) / 2 ;

[0106] Where n is the number of subsystems.

[0107] Furthermore, taking the case that the two power supplies of the cabinet come from the same UPS, assuming that its power supply structure is simple Figure 5 As shown, although the high and low voltage power supply subsystem and the UPS stand-alone are in an upstream and downstream relationship, when the output of the high and low voltage power supply subsystem is interrupted, as long as the UPS stand-alone system still maintains output, the back-end load power supply subsystem still has input; only when the output of the high and low voltage power supply subsystem is interrupted and the output of the UPS stand-alone is also interrupted, the input of the back-end load power supply subsystem fails. Therefore, the high and low voltage power supply subsystem and the UPS stand-alone are essentially in a parallel relationship, and the reliability of this part is:

[0108] R1=1-(1-R 高低压 )(1-P UPS单机 );

[0109] Only when the load power supply subsystem works normally, the upstream power can be supplied to the downstream. Therefore, the load power supply subsystem and the above parts are essentially in series. Therefore, the total reliability of the system is:

[0110] R 总 =R1R 负载供电 .

[0111] On the other hand, this embodiment also discloses a modular distribution system reliability assessment system, including:

[0112] A subsystem division module, used to obtain a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules;

[0113] A first model building module, used to build a plurality of evaluation sub-models based on the power supply structures of the plurality of sub-systems;

[0114] A second model building module is used to build a reliability evaluation model based on the power distribution system to be evaluated by using a plurality of evaluation sub-models;

[0115] An evaluation module is used to obtain reliability-related parameters according to the power distribution system to be evaluated, and input the reliability-related parameters into the reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

[0116] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0117] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A modular distribution system reliability assessment method, characterized in that: The specific steps are: Acquire a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules; Building a plurality of evaluation sub-models based on the power supply structures of the plurality of sub-systems; Based on the power distribution system to be evaluated, a reliability evaluation model is constructed using a plurality of evaluation sub-models; Reliability-related parameters are obtained according to the power distribution system to be evaluated, and the reliability-related parameters are input into the reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

2. The method for evaluating the reliability of a power distribution system based on modularization according to claim 1, characterized in that: The preset rule is set based on the degree of coupling between the various devices in the power distribution system to be evaluated.

3. The method for evaluating the reliability of a power distribution system based on modularization according to claim 1, characterized in that: The subsystems include a high and low voltage power supply subsystem, an uninterruptible power supply subsystem and a load power supply subsystem.

4. The method for evaluating the reliability of a power distribution system based on modularization according to claim 1, characterized in that: The construction steps of the evaluation sub-model are: Acquire historical data of each subsystem, and extract operation status change channels and fault data based on the historical data; the fault data includes operation status, fault occurrence probability and fault recovery probability; The evaluation sub-model of each sub-system is constructed based on the operation status change channel and the fault data of each sub-system.

5. The method for evaluating the reliability of a power distribution system based on modularization according to claim 1, characterized in that: The steps for constructing the reliability assessment model are: Based on the power distribution system to be evaluated, a routing sequence and a combination relationship of each subsystem are obtained, wherein the combination relationship includes a series relationship and a parallel relationship; Determine the combination mode of each evaluation sub-model according to the combination relationship of each sub-system; The plurality of evaluation sub-models are combined and connected in the combination mode based on the routing sequence to obtain the reliability evaluation model.

6. A modular-based distribution system reliability assessment method according to claim 5, characterized in that: When the combination relationship of each subsystem is a series relationship, the expression of the combination mode of each evaluation submodel is: R 系统 =R1×…×R n ; In the formula, R n is the reliability of n subsystems.

7. The modular-based distribution system reliability assessment method according to claim 5, characterized in that: When the combination relationship of each subsystem is a parallel relationship, the expression of the combination mode of each evaluation submodel is: R 系统 ={1-[1-R] 2 } n(n+1) / 2 ; Where n is the number of subsystems.

8. A modular distribution system reliability assessment system, characterized in that: include: A subsystem division module, used to obtain a power distribution system to be evaluated, and divide the power distribution system to be evaluated into multiple subsystems according to preset rules; A first model building module, used to build a plurality of evaluation sub-models based on the power supply structures of the plurality of sub-systems; A second model building module is used to build a reliability evaluation model based on the power distribution system to be evaluated by using a plurality of evaluation sub-models; An evaluation module is used to obtain reliability-related parameters according to the power distribution system to be evaluated, and input the reliability-related parameters into the reliability evaluation model to obtain the reliability of the power distribution system to be evaluated.

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