CN105787812A - MMC flexible ring network control device state analysis method - Google Patents

Abstract

The invention discloses an MMC flexible ring network control device state analysis method. The MMC flexible ring network control device state analysis method comprises the following steps: carrying out classification on states of an MMC flexible ring network control device, wherein one state is a normal working state; determining corresponding probability of the MMC flexible ring network control device in each state; determining probability of the MMC flexible ring network control device in normal working state according to the corresponding probability of the MMC flexible ring network control device in each state; and determining whether the MMC flexible ring network control device meets use requirements according to the probability of the MMC flexible ring network control device in the normal working state. The MMC flexible ring network control device state analysis method can solve the problem that a method capable of carrying out quantitative research on reliability of the flexible ring network control device in the prior art.

Description

The state analysis method of MMC flexibility loop network control device

Technical field

The present invention relates to power distribution system technology field, in particular to the state analysis method of a kind of MMC flexibility loop network control device.

Background technology

Feeder line interconnection switch in tradition 10kV power distribution network is all cold standby state, once distribution system breaks down, the preload putting into stand-by power supply in interconnection switch Guan Bi is in power down mode.Along with the tolerance degree of power-off event is constantly reduced by urban subscriber, it is necessary to improve the speed of power distribution network in-put of spare power supply as far as possible.A kind of new solution is to exchange at tradition 10kV to add modular multilevel (ModularMulti-levelConverter in distribution, MMC) flexible direct current looped network device, utilizes flexible direct current the feature of quick control can put into stand-by power supply within the shortest time.But flexible direct current looped network device itself is more complicated, operationally yet suffer from certain risk, it is thus desirable to a kind of method that this device reliability can be carried out quantitative study, thus the properly functioning probability of device, probability of malfunction are analyzed, and then using analyzing result as the reference selecting flexible direct current looped network device, select suitable flexible direct current looped network device.

Summary of the invention

The purpose of the present invention is to propose to the state analysis method of a kind of MMC flexibility loop network control device, with the problem solving to need a kind of method that the reliability of this flexibility loop network control device can carry out quantitative study in prior art.

According to an aspect of the invention, it is provided the state analysis method of a kind of MMC flexibility loop network control device, including:

The state of MMC flexibility loop network control device is classified, and one of which state is normal operating conditions；

Determine that MMC flexibility loop network control device is in the corresponding probability of each state；

The corresponding probability being in each state according to MMC flexibility loop network control device determines that MMC flexibility loop network control device is in the probability of normal operating conditions；

Whether the probability judgment MMC flexibility loop network control device being in normal operating conditions according to MMC flexibility loop network control device meets instructions for use.

Preferably, the state of MMC flexibility loop network control device also include following at least one:

Main circuit fault, main circuit reparation, main circuit installation, control circuit fault, maintenance.

Preferably, the step of the corresponding probability that the described MMC of determination flexibility loop network control device is in each state is undertaken by equation below:

$\left\{\begin{array}{c}{p}_1=1-\underset{i\∈\[2,6\]}{\mathrm{\Σ}}{p}_i\\ p_2=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_S\\ p_3=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_R\\ p_4=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_S{\mathrm{\μ}}_M{\mathrm{\μ}}_R\\ p_5=A^{-1}{\mathrm{\λ}}_M{\mathrm{\μ}}_C{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\\ p_6=A^{-1}{\mathrm{\λ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\end{array}\right.$

Wherein A=λ_Fμ_Cμ_M(μ_Rμ_S+μ_Nμ_R+μ_Nμ_S)+μ_Nμ_Rμ_S(λ_Cμ_M+λ_Mμ_C+μ_Cμ_M)；

p₁The probability of normal operating conditions it is in for device；p₂The probability of main circuit malfunction it is in for device；p₃The probability of normal operating conditions it is in for device；p₄The probability of main circuit malfunction it is in for device；p₅The probability of normal operating conditions it is in for device；p₆The probability of main circuit malfunction it is in for device；λ_MFor the maintenance number of times that device carries out every year；λ_FFault rate for device main circuit fault；λ_CFault rate for device control circuit fault；μ_RFor finding main circuit fault and starting the efficiency repaired；μ_SFor carrying out the efficiency of main circuit reparation；μ_NEfficiency for erecting device；μ_CNormal efficiency is recovered for control circuit；μ_MThe efficiency overhauled is carried out for device.

Preferably, λ_FObtained by equation below:

λ_F=12 (λ₁+λ₂)+2λ₃

Wherein λ₁It is by the wall scroll brachium pontis fault rate of SM module composition；λ₂It is the fault rate of current-limiting reactor on wall scroll brachium pontis, is the intrinsic parameter of element；λ₃It is the fault rate of DC side electric capacity of voltage regulation, is the intrinsic parameter of element.

Preferably, λ₁Obtained by equation below:

$\left\{\begin{array}{c}P=e^{-{\mathrm{N\λ}}_{SM}}\\ R=P^n+\underset{i=\mathrm{1..}m,}{\mathrm{\Σ}}{C}_n^i{(1-P)}^i{P}^{n-i}\\ {\mathrm{\λ}}_1=-\ln R\end{array}\right.$

Wherein λ_SMFor the fault rate of single SM module, it it is the intrinsic parameter of element；P is the single SM module trouble-proof probability of continuous operation N；N is determined by the SM module real work time limit；R is the wall scroll brachium pontis reliability with m spare module.

The state analysis method of the MMC flexibility loop network control device of the present invention, each shape probability of state can be according to MMC flexibility loop network control device and determine that MMC flexibility loop network control device is in the probability of normal operating conditions, the probability that then MMC flexibility loop network control device is in normal operating conditions compares with goal-selling probability, determine whether MMC flexibility loop network control device meets dependability requirement, thus the reliability of flexible loop network control device is carried out quantitative study, the selection for MMC flexibility loop network control device provides reliable basis.

Accompanying drawing explanation

Accompanying drawing described herein is used for providing a further understanding of the present invention, constitutes the part of the application, and the schematic description and description of the present invention is used for explaining the present invention, is not intended that inappropriate limitation of the present invention.In the accompanying drawings:

Fig. 1 is the first state transition diagram of the MMC flexibility loop network control device of the embodiment of the present invention；

Fig. 2 is the second state transition diagram of the MMC flexibility loop network control device of the embodiment of the present invention；

Fig. 3 is the state analysis method flow chart of the MMC flexibility loop network control device of the embodiment of the present invention.

Detailed description of the invention

In the following detailed description, it is proposed to a large amount of specific detail, in order to thorough understanding of the present invention is provided.However it will be understood by those of ordinary skill in the art that, the present invention also can be implemented even without these specific detail.In other cases, it does not have well-known method, process, assembly and circuit are described in detail, in order to avoid affecting the understanding of the present invention.

In conjunction with referring to shown in Fig. 1 to Fig. 3, according to embodiments of the invention, the state analysis method of MMC flexibility loop network control device includes: the state of MMC flexibility loop network control device is classified, and one of which state is normal operating conditions；Determine that MMC flexibility loop network control device is in the corresponding probability of each state；The corresponding probability being in each state according to MMC flexibility loop network control device determines that MMC flexibility loop network control device is in the probability of normal operating conditions；Whether the probability judgment MMC flexibility loop network control device being in normal operating conditions according to MMC flexibility loop network control device meets instructions for use.

By adopting this state analysis method, can determine that (such as 1 year) MMC flexibility loop network control device is in the probability of normal operating conditions within some period quickly and easily, thus be in the probability of normal operating conditions according to this MMC flexibility loop network control device, judge whether this MMC flexibility loop network control device disclosure satisfy that the access demand of distribution system, selection for MMC flexibility loop network control device provides effective reference, improve the selection efficiency of MMC flexibility loop network control device, reduce the probability broken down after MMC flexibility loop network control device is selected, improve the overall serviceability of distribution system.

In conjunction with shown in Figure 1, the state of MMC flexibility loop network control device also include following at least one: main circuit fault, main circuit reparation, main circuit installation, control circuit fault, maintenance.In the present embodiment, the state of MMC flexibility loop network control device includes normal operation, main circuit fault, main circuit reparation, main circuit installation, control circuit fault, overhauls these six kinds, the state of MC flexibility loop network control device mainly shifts between these six kinds of states, it is determined by MMC flexibility loop network control device at these six kinds of shape probability of states, it is possible to the status of MMC flexibility loop network control device is carried out accurate analysis.

In the present embodiment, the step of the corresponding probability that the described MMC of determination flexibility loop network control device is in each state is undertaken by equation below:

$\left\{\begin{array}{c}{p}_1=1-\underset{i\∈\[2,6\]}{\mathrm{\Σ}}{p}_i\\ p_2=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_S\\ p_3=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_R\\ p_4=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_S{\mathrm{\μ}}_M{\mathrm{\μ}}_R\\ p_5=A^{-1}{\mathrm{\λ}}_M{\mathrm{\μ}}_C{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\\ p_6=A^{-1}{\mathrm{\λ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\end{array}\right.$

Wherein A=λ_Fμ_Cμ_M(μ_Rμ_S+μ_Nμ_R+μ_Nμ_S)+μ_Nμ_Rμ_S(λ_Cμ_M+λ_Mμ_C+μ_Cμ_M)；

p₁The probability of normal operating conditions it is in for device；p₂The probability of main circuit malfunction it is in for device；p₃The probability of normal operating conditions it is in for device；p₄The probability of main circuit malfunction it is in for device；p₅The probability of normal operating conditions it is in for device；p₆The probability of main circuit malfunction it is in for device；λ_MFor the maintenance number of times that device carries out every year；λ_FFault rate for device main circuit fault；λ_CFault rate for device control circuit fault；μ_RFor finding main circuit fault and starting the efficiency repaired；μ_SFor carrying out the efficiency of main circuit reparation；μ_NEfficiency for erecting device；μ_CNormal efficiency is recovered for control circuit；μ_MThe efficiency overhauled is carried out for device.Wherein except λ_FOutside parameter all can pass through the method adding up or test and obtain.

Owing to the main circuit of MMC flexibility loop network control device is transformation of electrical energy link, comprising many elements, wherein any one link fault may result in the stoppage in transit of whole device, and the relation therefore can logically connected asks for main circuit dependability parameter λ_F, λ_FBy can equation below obtain:

λ_F=12 (λ₁+λ₂)+2λ₃

Wherein λ₁It is by the wall scroll brachium pontis fault rate of SM module composition；λ₂It is the fault rate of current-limiting reactor on wall scroll brachium pontis, is the intrinsic parameter of element；λ₃It is the fault rate of DC side electric capacity of voltage regulation, is the intrinsic parameter of element.

Owing to the SM module of every brachium pontis is all with Redundancy Design, it is assumed that be furnished with n SM module on single brachium pontis, wherein m SM module is in resting state, then λ₁Can be obtained by equation below:

$\left\{\begin{array}{c}P=e^{-{\mathrm{N\λ}}_{SM}}\\ R=P^n+\underset{i=\mathrm{1..}m,}{\mathrm{\Σ}}{C}_n^i{(1-P)}^i{P}^{n-i}\\ {\mathrm{\λ}}_1=-\ln R\end{array}\right.$

Wherein λ_SMFor the fault rate of single SM module, it it is the intrinsic parameter of element；P is the single SM module trouble-proof probability of continuous operation N；N is determined by the SM module real work time limit；R is the wall scroll brachium pontis reliability with m spare module, it is possible to by λ_SMTry to achieve.

By above-mentioned mode, can progressively determine that MMC flexibility loop network control device is in other the five kinds of shape probability of states except normal operating conditions, then can according to five kinds of calculated probability, determine that MMC flexibility loop network control device is in the probability of normal operating conditions, then it is in whether the current MMC flexibility loop network control device of the probability judgment of normal operating conditions disclosure satisfy that the reliability requirement of distribution system according to MMC flexibility loop network control device, thus choosing offer reliable basis for MMC flexibility loop network control device, the reliability of whole distribution system after raising MMC flexibility loop network control device access distribution system, improve overall performance and the operation stability of distribution system.

On the basis of Fig. 1, owing to state 2,3,4,6 broadly falls into malfunction, therefore a malfunction can be merged into simplified model, thus obtain typical three condition reliability model, as shown in Figure 2.With λ ' in Fig. 2_FRepresent that device has at least the fault rate of place's fault, by λ '_F=λ_C+λ_FCalculate；With μ '_FRepresent the repair rate that device recovers from fault, pass throughCalculate.By simplifying the state model of MMC flexibility loop network control device, it is possible to reduce the state analysis complexity of MMC flexibility loop network control device, improve the state analysis efficiency of MMC flexibility loop network control device.

Below in conjunction with example, the state analysis method of MMC flexibility loop network control device is illustrated:

Wherein known quantity represents the parameter that a certain concrete MMC flexibility loop network control device can directly be determined, unknown quantity represents the unknown parameter that needs are determined according to known parameter, by above-mentioned method and formula, it is possible to try to achieve unknown quantity according to known quantity.By determined unknown quantity it is known that the probability that this MMC flexibility loop network control device is in normal operating conditions is p₁=0.9967, it is assumed that meet the MMC flexibility loop network control device of distribution system demand and be in the probability of normal operating conditions and should be not less than 0.99, due to p₁Higher than 0.99, therefore without this MMC flexibility loop network control device is additionally adjusted, can meeting the access requirement of current power distribution systems, this MMC flexibility loop network control device disclosure satisfy that the dependability requirement of current distribution system.

The explanation of above example is only intended to help to understand method and the core concept thereof of the present invention；Simultaneously for one of ordinary skill in the art, according to the thought of the present invention, all will change in specific embodiments and applications, in sum, this specification content should not be construed as limitation of the present invention.

Claims (5)

1. the state analysis method of a MMC flexibility loop network control device, it is characterised in that including:

The state of MMC flexibility loop network control device is classified, and one of which state is normal operating conditions；

Determine that MMC flexibility loop network control device is in the corresponding probability of each state；

The corresponding probability being in each state according to MMC flexibility loop network control device determines that MMC flexibility loop network control device is in the probability of normal operating conditions；

Whether the probability judgment MMC flexibility loop network control device being in normal operating conditions according to MMC flexibility loop network control device meets instructions for use.

2. state analysis method according to claim 1, it is characterised in that the state of MMC flexibility loop network control device also include following at least one:

Main circuit fault, main circuit reparation, main circuit installation, control circuit fault, maintenance.

3. state analysis method according to claim 2, it is characterised in that the step of the corresponding probability that the described MMC of determination flexibility loop network control device is in each state is undertaken by equation below:

$\left\{\begin{array}{c}{p}_1=1-\underset{i\∈\[2,6\]}{\Σ}{p}_i\\ p_2=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_S\\ p_3=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_N{\mathrm{\μ}}_R\\ p_4=A^{-1}{\mathrm{\λ}}_F{\mathrm{\μ}}_C{\mathrm{\μ}}_S{\mathrm{\μ}}_M{\mathrm{\μ}}_R\\ p_5=A^{-1}{\mathrm{\λ}}_M{\mathrm{\μ}}_C{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\\ p_6=A^{-1}{\mathrm{\λ}}_C{\mathrm{\μ}}_M{\mathrm{\μ}}_R{\mathrm{\μ}}_S{\mathrm{\μ}}_N\end{array}\right.$

Wherein A=λ_Fμ_Cμ_M(μ_Rμ_S+μ_Nμ_R+μ_Nμ_S)+μ_Nμ_Rμ_S(λ_Cμ_M+λ_Mμ_C+μ_Cμ_M)；

p₁The probability of normal operating conditions it is in for device；p₂The probability of main circuit malfunction it is in for device；p₃The probability of normal operating conditions it is in for device；p₄The probability of main circuit malfunction it is in for device；p₅The probability of normal operating conditions it is in for device；p₆The probability of main circuit malfunction it is in for device；λ_MFor the maintenance number of times that device carries out every year；λ_FFault rate for device main circuit fault；λ_CFault rate for device control circuit fault；μ_RFor finding main circuit fault and starting the efficiency repaired；μ_SFor carrying out the efficiency of main circuit reparation；μ_NEfficiency for erecting device；μ_CNormal efficiency is recovered for control circuit；μ_MThe efficiency overhauled is carried out for device.

4. state analysis method according to claim 3, it is characterised in that λ_FObtained by equation below:

λ_F=12 (λ₁+λ₂)+2λ₃

Wherein λ₁It is by the wall scroll brachium pontis fault rate of SM module composition；λ₂It is the fault rate of current-limiting reactor on wall scroll brachium pontis, is the intrinsic parameter of element；λ₃It is the fault rate of DC side electric capacity of voltage regulation, is the intrinsic parameter of element.

5. state analysis method according to claim 4, it is characterised in that λ₁Obtained by equation below:

$\left\{\begin{array}{c}P=e^{-{\mathrm{N\λ}}_{SM}}\\ R=P^n+\underset{i=\mathrm{1..}m,}{\mathrm{\Σ}}{C}_n^i{(1-P)}^i{P}^{n-i}\\ {\mathrm{\λ}}_1=-\ln R\end{array}\right.$

Wherein λ_SMFor the fault rate of single SM module, it it is the intrinsic parameter of element；P is the single SM module trouble-proof probability of continuous operation N；N is determined by the SM module real work time limit；R is the wall scroll brachium pontis reliability with m spare module.