CN109307825B - Method and system for acquiring fault measure quantity of direct-current single-pole line of flexible direct-current power grid - Google Patents

Abstract

The invention discloses a method and a system for acquiring fault measure quantity of a direct-current single-pole line of a flexible direct-current power grid, and belongs to the technical field of safety and stability control of a power system. The method comprises the following steps: determining a flexible direct current power grid security control system topological structure; acquiring calculation data of fault measure quantity of the safety control system of the flexible direct current power grid according to the topological structure; defining a fault measure quantity calculation variable of a safety control system of the flexible direct current power grid according to the converter blocking fault; and acquiring the fault measure quantity according to the calculation data and the calculation variable. The method ensures that the safety control system of the flexible direct current power grid can calculate the correct fault measure amount when the converter locking fault occurs, and can effectively ensure the safe and stable operation of the flexible direct current power grid.

Description

Method and system for acquiring fault measure quantity of direct-current single-pole line of flexible direct-current power grid

Technical Field

The invention relates to the technical field of safety and stability control of an electric power system, in particular to a method and a system for acquiring fault measure quantity of a direct-current unipolar line of a flexible direct-current power grid.

Background

The grid-connected transmission and consumption of large-scale new energy power generation have important significance. The flexible direct current transmission is an advanced direct current transmission technology, a flexible direct current power grid is formed based on the flexible direct current transmission technology, new energy sources in different regions and different types can be combined in a grid, and functions of stabilizing output fluctuation of the new energy sources and the like are achieved. Therefore, the flexible direct-current power grid has remarkable advantages in the aspect of new energy power generation grid connection consumption, and is one of important directions of future power grid development.

The safety control device of the power system is an auxiliary technology which is developed along with the continuous development of a power grid and is used for improving the safety and stability of the power grid. The safety control device of the power system mainly aims at improving the safety and stability level of a power grid and is mainly used for transient stability control of a plurality of plants or a single plant in a wide area. The safety control device consists of a main station, a plurality of substations and an execution station, and the function realization process comprises the following steps: collecting real-time operation information and fault information of a power grid, judging faults, calculating fault measure quantity, issuing instructions and executing the instructions. Wherein, the calculation of the fault measure amount is the core function of the safety control device.

The safety control system of the flexible direct current power grid has the functions of carrying out fault judgment by collecting real-time operation information and fault information of the flexible direct current power grid, carrying out fault measure calculation according to fault types, realizing fault ride-through of the flexible direct current power grid through measures such as a generator tripping and load shedding and ensuring safe and stable operation of the flexible direct current power grid system.

At present, for flexible direct current power grid engineering, a design method of a safety control device of the flexible direct current power grid engineering is lacked, particularly a method for calculating fault measure quantity of a safety control system under the fault condition is lacked, and the lacked method seriously threatens the safe and stable operation level of the flexible direct current power grid engineering.

Disclosure of Invention

The invention aims to solve the problem that the current method for calculating the fault measure quantity of a safety control system under the condition of lack of converter locking faults for flexible direct-current power grid engineering ensures the safe and stable operation of the flexible direct-current power grid engineering, and provides a method for acquiring the fault measure quantity of a direct-current unipolar line of the flexible direct-current power grid, which comprises the following steps:

determining a flexible direct current power grid security control system topological structure;

acquiring calculation data of the fault measure quantity of the direct-current single-pole line of the security control system of the flexible direct-current power grid according to the topological structure;

defining a fault measure quantity calculation variable of a direct-current single-pole line of a safety control system of the flexible direct-current power grid according to a converter blocking fault;

and acquiring the fault measure quantity of the direct-current unipolar line according to the calculation data and the calculation variable.

Optionally, the flexible direct current power grid safety control system topological structure includes: the flexible direct-current power grid security control system is of a true bipolar topological structure and the flexible direct-current power grid security control system is of a true unipolar topological structure.

Optionally, calculating data includes:

a converter station Si, where i is the ith converter station, and i is 1, 2, 3, 4.. n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_i_P} Operating power before failure P _{S0_i_P} Maximum band-rotating power quantity delta P _{S_i_P} And a valid bit V _{S_i_P} ；

A converter station Si cathode layer converter Si _ N variable: maximum power P _{Smax_i_N} Operating power before failure P _{S0_i_N} Maximum band-rotating power quantity delta P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is the ith direct current transmission line, and i is 1, 2, 3, 4.. n;

variable of transmission line Li _ P of Li positive electrode layer of line: maximum power P _Lmax Initial operating power P _{L0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative pole layer of line: maximum power P _Lmax Initial operating power P _{L0_i_N} And a valid bit V _{L_i_N} ；

And the operation of the converter station Si variable is set to be 1, and the exit is set to be 0.

Optionally, the defined calculation variables include:

the unbalanced power of the system is delta P, and the maximum transfer power of the non-fault pole layer current converter isΔP’ _{S_i_max} Wherein is Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} ) The maximum strip power of the non-fault electrode layer is delta P' _∑maxM Wherein is Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} ) The maximum strip power of the non-fault electrode layer line is delta P' _∑maxL Wherein is Δ P' _∑maxL ＝V _{L_1_x′} ×(P _Lmax -P _{L0_1_x′} )+V _{L_2_x′} ×(P _Lmax -P _{L0_2_x′} ) The system can transfer the band power to delta P _trans Wherein Δ P _trans ＝min{ΔP’ _{S_i_max} ，ΔP’ _∑maxM ，ΔP’ _∑maxL And the quantity of faulty action is Ptrip.

Optionally, calculating the failure measure amount according to the calculation data and the calculation variable specifically includes:

if the line L is _i Failure, then its V _{L_i_x} From 1 to 0;

recording the line-in-operation number K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +V _{L_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _Lmax Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _Lmax -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +V _{S_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans Amount of faulty measure

When V is _{L_1_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_4_} x＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_3_x} 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

The invention also provides a system for acquiring the fault measure quantity of the direct-current single-pole line of the flexible direct-current power grid, which comprises the following steps:

determining a topological structure module, and determining a topological structure of the safety control system of the flexible direct current power grid;

the data acquisition module is used for acquiring the calculation data of the fault measure quantity of the direct-current single-pole line of the safety control system of the flexible direct-current power grid according to the topological structure;

the method comprises the steps that a variable module is obtained, and a variable is calculated according to the current converter blocking fault definition direct-current single-pole line fault measure quantity of the safety control system of the flexible direct-current power grid;

and the fault measure quantity obtaining module is used for obtaining the fault measure quantity of the direct current unipolar line according to the calculation data and the calculation variable.

Optionally, the flexible direct current power grid security control system topology includes: the flexible direct-current power grid security control system is of a true bipolar topological structure and the flexible direct-current power grid security control system is of a true unipolar topological structure.

Optionally, calculating data includes:

a converter station Si, where i is the ith converter station, and i is 1, 2, 3, 4.. n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_i_P} Pre-fault operating power PS _{0_i_P} Maximum tape transfer power amount Δ P _{S_i_P} And a valid bit V _{S_i_P} ；

Variable of a converter station Si cathode layer converter Si _ N: maximum power P _{Smax_i_N} Operating power before failure P _{S0_i_N} Maximum tape transfer power amount Δ P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is the ith direct current transmission line, and i is 1, 2, 3, 4.. n;

variable of transmission line Li _ P of Li positive layer of line: maximum power P _Lmax Initial operating power PL _{0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative pole layer of line: maximum power P _Lmax Initial operating power PL _{0_i_N} And a valid bit V _{L_i_N} ；

And the variable operation of the converter station Si and the variable operation of the line Li are set to be 1, and the exit is set to be 0.

Optionally, the defined calculation variables include:

the unbalanced power of the system is delta P, the maximum converter band-turning power of the non-fault pole layer converter is delta P' _{S_i_max} Wherein is Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} ) The maximum strip power of the non-faulty electrode layer is delta P' _∑maxM Wherein is Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} ) Delta P 'is the maximum rotating power of the line of the non-failure electrode layer' _∑maxL Wherein is Δ P' _∑maxL ＝V _{L_1_x′} ×(P _Lmax -P _{L0_1_x′} )+V _{L_2_x′} ×(P _Lmax -P _{L0_2_x} ') system, system transferable band power is DeltaP _trans In which Δ P _trans ＝min{ΔP’ _{S_i_max} ，ΔP’ _∑maxM ，ΔP’ _∑maxL And the quantity of faulty action is Ptrip.

Optionally, the calculating the fault measure quantity according to the calculation data and the calculation variable specifically includes:

if the line L is _i Failure, then its V _{L_i_x} From 1 to 0;

recording the number of the circuits in operation K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +VL _{_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _Lmax Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _Lmax -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +VS _{_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_} x+P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans Amount of faulty measure

When V is _{L_1_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_4_x} ＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the average value is equal to 0, the alloy,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_3_x} is equal to 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and Δ P _trans If delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

The method ensures that the safety control system of the flexible direct-current power grid can calculate the correct fault measure amount when the converter locking fault occurs, and can effectively ensure the safe and stable operation of the flexible direct-current power grid.

Drawings

FIG. 1 is a diagram of a true bipolar topology structure of a security control system of a flexible direct current power grid according to a method for obtaining a fault measure quantity of a direct current unipolar line of the flexible direct current power grid;

FIG. 2 is a wiring diagram of a flexible direct current power grid security control system true bipolar topological structure engineering for a method for obtaining a flexible direct current power grid DC single-pole line fault measure quantity of the invention;

FIG. 3 is a flowchart of a method for obtaining a fault measure quantity of a DC single-pole line of a flexible DC power grid according to the present invention;

fig. 4 is a system configuration diagram for acquiring the fault measure quantity of the dc unipolar line of the flexible dc power grid according to the present invention.

Detailed Description

The invention provides a method for acquiring fault measure quantity of a direct-current single-pole line of a flexible direct-current power grid, which comprises the following steps of:

determining a flexible direct current power grid security control system topological structure, wherein the flexible direct current power grid security control system topological structure comprises: the flexible direct-current power grid security control system is of a true bipolar topological structure and a flexible direct-current power grid security control system is of a true monopolar topological structure;

the flexible direct current ring-shaped power grid adopts a true bipolar structure, the number of the converter stations is more than 3, the invention takes four-end true bipolar flexible direct current ring network engineering as an example for introduction, the topological structure is shown in figure 1, four flexible direct current converter stations S1, S2, S3 and S4 are connected through direct current transmission lines L1, L2, L3 and L4 to form the flexible direct current ring-shaped power grid, the flexible direct current ring-shaped power grid adopts a true bipolar structure, each converter station comprises a positive pole layer converter and a negative pole layer converter, and the alternating current sides of the two converters are connected with each other; the direct current transmission line comprises a positive pole layer direct current transmission line and a negative pole layer direct current transmission line, and two ends of each direct current transmission line are provided with direct current circuit breakers. Each pole layer has 4 converter stations, 4 lines and 8 direct current breakers.

Taking a single pole layer as an example, the specific connection mode is shown in fig. 2, wherein the direct current transmission lines on the same pole layer form a ring network, both ends of each direct current line are provided with direct current circuit breakers, and when a ground fault or maintenance occurs to the direct current lines, the direct current circuit breakers at both ends of the direct current lines can be disconnected for isolation; the current converter is connected to a ring network formed by direct current lines through the mechanical quick switch, and when the current converter is locked due to faults or maintenance, the current converter can be cut off from the direct current ring network by disconnecting the mechanical quick switch without influencing the node on the ring network.

Because the AC sides of the positive pole layer converter and the negative pole layer converter of the same converter station are connected and the power distribution between the two converters is controllable, when the capacity which can be transmitted by one pole layer converter is reduced due to faults and the like, redundant power can be transmitted by the other pole layer converter, the process is called power transfer band, and the power transfer band between the pole layers can be realized through the power transfer band between the converters.

Acquiring calculation data of the fault measure quantity of the direct-current single-pole line of the safety control system of the flexible direct-current power grid according to the topological structure;

wherein calculating the data comprises:

a converter station Si, where i is the ith converter station, and i is 1, 2, 3, 4.. n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_i_P} Pre-fault operating power PS _{0_i_P} Maximum band-rotating power quantity delta P _{S_i_P} And a valid bit V _{S_i_P} ；

A converter station Si cathode layer converter Si _ N variable: maximum power P _{Smax_i_N} Pre-fault operating power PS _{0_i_N} Maximum tape transfer power amount Δ P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is an ith dc transmission line, and i is 1, 2, 3, 4.. n;

variable of transmission line Li _ P of Li positive electrode layer of line: maximum power P _Lmax Initial operating power PL _{0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative pole layer of line: maximum power P _Lmax Initial operating power PL _{0_i_N} And a valid bit V _{L_i_N} ；

And the variable operation of the converter station Si and the variable operation of the line Li are set to be 1, and the exit is set to be 0.

Defining a fault measure quantity calculation variable of a direct-current unipolar line of a safety control system of the flexible direct-current power grid according to a converter blocking fault;

the defined computational variables include:

the system unbalanced power is delta P, and the maximum strip-rotating power of the non-fault pole layer converter is delta P' _{S_i_max} Wherein is Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} ) The maximum strip power of the non-fault electrode layer is delta P' _∑maxM Wherein Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} ) The maximum strip power of the non-fault electrode layer line is delta P' _∑maxL Wherein is Δ P' _∑maxL ＝V _{L_1_x′} ×(P _Lmax -P _{L0_1_x′} )+V _{L_2_x′} ×(P _Lmax -P _{L0_2_x′} ) The system can transfer the band power to delta P _trans In which Δ P _trans ＝min{ΔP’ _{S_i_max} ，ΔP’ _∑maxM ，ΔP’ _∑maxL And the quantity of faulty action is Ptrip.

Wherein, the unbalanced power of the system is Δ P: the unbalanced power caused by the fault needs to be transferred; if the power of the rotatable belt is insufficient, a fan at the cutting and feeding end is needed;

maximum strip power of inverter of non-fault electrode layer is delta P' _{S_i_max} : the residual capacity margin of the converter with a non-fault pole layer of the converter with a fault, namely the maximum converter power quantity delta P of the converter _{S_i_x} ；

The maximum strip power of the non-fault electrode layer is delta P' _∑maxM : the sum of the residual capacity margins of all converters on the non-fault pole layer is referred to, namely the maximum transferable power between the pole layers considering the capacity limit of the converters;

the maximum strip power of a non-fault electrode layer line is delta P' _∑maxL : after the switching is considered, the minimum value of the capacity margins of each direct current line of the non-fault pole layer is considered, namely the maximum switchable power between the pole layers which is limited by the capacity of the direct current line is considered;

system transferable band power is delta P _trans : the transferable power is delta P' _{S_i_max} 、ΔP’ _∑maxM 、ΔP’ _∑maxL The minimum of the three;

the failure measure quantity is Ptrip: the power of the fan which needs to be cut at the sending end is the difference between the unbalanced power of the system and the power of the rotatable belt, and if the unbalanced power of the system is smaller than the difference between the power of the rotatable belt, the machine cutting amount is 0.

Obtaining the fault measure quantity of the direct current unipolar line according to the calculation data and the calculation variable, specifically comprising:

if the line L is _i Failure, then its V _{L_i_x} From 1 to 0;

recording the line-in-operation number K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +V _{L_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _Lmax Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _Lmax -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +V _{S_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans Amount of faulty measure

When V is _{L_1_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_4_x} ＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans If delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the average value is equal to 0, the alloy,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_3_x} is equal to 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and P _trans If delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

The invention also provides a system 200 for obtaining the fault measure quantity of the direct-current unipolar line of the flexible direct-current power grid, as shown in fig. 4, the system comprises:

determining a topological structure module 201, determining a topological structure of a flexible direct current power grid security control system, wherein the topological structure of the flexible direct current power grid security control system comprises: the flexible direct-current power grid security control system is of a true bipolar topology structure and the flexible direct-current power grid security control system is of a true monopolar topology structure.

The data obtaining module 202 obtains calculation data of the fault measure quantity of the direct-current unipolar line of the safety control system of the flexible direct-current power grid according to the topological structure, wherein the calculation data includes:

a converter station Si, where i is the ith converter station, and i is 1, 2, 3, 4.. n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_} i _{_P} Operating power before failure P _{S0_i_P} Maximum band-rotating power quantity delta P _{S_i_P} And a valid bit V _{S_i_P} ；

Variable of a converter station Si cathode layer converter Si _ N: maximum power P _{Smax_i_N} Operating power before failure P _{S0_i_N} Maximum band-rotating power quantity delta P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is an ith dc transmission line, and i is 1, 2, 3, 4.. n;

variable of transmission line Li _ P of Li positive layer of line: maximum power P _Lmax Initial operating power P _{L0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative layer of line: maximum power P _Lmax Initial operating power P _{L0_i_N} And a valid bit V _{L_i_N} ；

And the operation of the converter station Si variable is set to be 1, and the exit is set to be 0.

The variable obtaining module 203 defines a calculation variable of the fault measure quantity of the direct-current unipolar line of the safety control system of the flexible direct-current power grid according to the blocking fault of the converter, wherein the defined calculation variable includes: the system unbalanced power is delta P, and the maximum strip-rotating power of the non-fault pole layer converter is delta P' _{S_i_max} Wherein is Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} ) The maximum strip power of the non-faulty electrode layer is delta P' _∑maxM Wherein Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} ) The maximum strip power of the non-fault electrode layer line is delta P' _∑maxL Wherein is Δ P' _∑maxL ＝V _{L_1_x′} ×(P _Lmax -P _{L0_1_x′} )+V _{L_2_x′} ×(P _Lmax -P _{L0_2_x′} ) The system can transfer the band power to delta P _trans In which Δ P _trans ＝min{ΔP’ _{S_i_max，} ΔP’ _∑maxM ，ΔP’ _∑maxL And the quantity of faulty action is Ptrip.

The system unbalanced power is Δ P: the unbalanced power caused by the fault needs to be transferred; if the power of the rotatable belt is insufficient, a fan at the cutting and feeding end is needed;

maximum strip power of inverter of non-fault electrode layer is delta P' _{S_i_max} : the residual capacity margin of the converter with a non-fault pole layer of the converter with a fault, namely the maximum converter power quantity delta P of the converter _{S_i_x} ；

The maximum strip power of the non-fault electrode layer is delta P' _∑maxM : the sum of the residual capacity margins of all converters on the non-fault pole layer is referred to, namely the maximum transferable power between the pole layers considering the capacity limit of the converters;

the maximum strip power of a non-fault electrode layer line is delta P' _∑maxL : after the switching is considered, the minimum value of the capacity margin of each direct current line of the non-fault pole layer is considered, namely the maximum switchable power between the pole layers which is limited by the capacity of the direct current line is considered;

system transferable band power is delta P _trans : the transferable power is delta P' _{S_i_max} 、ΔP’ _∑maxM 、ΔP’ _∑maxL The minimum of the three;

the number of faulty measures is Ptrip: the power of the fan which needs to be cut at the sending end is the difference between the unbalanced power of the system and the power of the rotatable belt, and if the unbalanced power of the system is smaller than the difference between the power of the rotatable belt, the machine cutting amount is 0.

And a fault measure quantity obtaining module 204 for obtaining the fault measure quantity of the direct current unipolar line according to the calculation data and the calculation variable. The method specifically comprises the following steps:

if the line L is _i At fault, then V _{L_i_x} From 1 to 0;

recording the line-in-operation number K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +V _{L_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _Lmax Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _Lmax -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +V _{S_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans Amount of faulty measure

When V is _{L_1_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_4_x} ＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the average value is equal to 0, the alloy,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans Then the fault measuresApplication amount P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_3_x} is equal to 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

The method ensures that the safety control system of the flexible direct-current power grid can calculate the correct fault measure amount when the converter locking fault occurs, and can effectively ensure the safe and stable operation of the flexible direct-current power grid.

Claims (8)

1. A method of obtaining a flexible direct current grid dc single pole line fault measure quantity, the method comprising:

determining a flexible direct current power grid security control system topological structure;

acquiring calculation data of the fault measure quantity of the direct-current single-pole line of the safety control system of the flexible direct-current power grid according to the topological structure;

the calculation data comprises:

a converter station Si, where i is the ith converter station, i is 1, 2, 3, 4 … n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_i_P} Failure ofFront running power P _{S0_i_P} Maximum band-rotating power quantity delta P _{S_i_P} And a valid bit V _{S_i_P} ；

Variable of a converter station Si cathode layer converter Si _ N: maximum power P _{Smax_i_N} Operating power before failure P _{S0_i_N} Maximum band-rotating power quantity delta P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is the ith dc transmission line, and i is 1, 2, 3, 4 … n;

variable of transmission line Li _ P of Li positive electrode layer of line: maximum power P _{Lmax_i_P} Initial operating power P _{L0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative pole layer of line: maximum power P _{Lmax_i_N} Initial operating power P _{L0_i_N} And a valid bit V _{L_i_N} ；

The variable commissioning of the converter station Si and the line Li is set to be 1, and the quitting is set to be 0;

defining a fault measure quantity calculation variable of a direct-current unipolar line of a safety control system of the flexible direct-current power grid according to a converter blocking fault;

and acquiring the fault measure quantity of the direct-current unipolar line according to the calculation data and the calculation variable.

2. The method of claim 1, wherein the flexible direct current power grid safety control system topology comprises: the flexible direct-current power grid security control system is of a true bipolar topological structure and the flexible direct-current power grid security control system is of a true unipolar topological structure.

3. The method of claim 1, the defined computational variables comprising:

the unbalanced power of the system is delta P;

maximum converter strip-rotating power of non-fault pole layer converter is delta P' _{S_i_max} Wherein Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} )；

The maximum strip power of the non-fault electrode layer is delta P' _∑maxM Wherein is Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} )；

The maximum rotating band power of the line of the non-fault electrode layer is delta P' _∑maxL Wherein Δ P' _∑maxL ＝V _{L_1_x′} ×(P _{Lmax_i_P} -P _{L0_1_x′} )+V _{L_2_x′} ×(P _{Lmax_i_P} -P _{L0_2_x′} )；

System transferable band power is delta P _trans Wherein Δ P _trans ＝min{ΔP’ _{S_i_max} ，ΔP’ _∑maxM ，ΔP’ _∑maxL }；

Amount of faulty measure P _trip ＝ΔP-ΔP _trans 。

4. The method according to claim 3, wherein said calculating the fault measure quantity based on the calculation data and the calculation variables comprises:

if the line L is _i Failure, then its V _{L_i_x} From 1 to 0;

recording the line-in-operation number K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +V _{L_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _{Lmax_i_P} Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _{Lmax_i_P} -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +V _{S_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_1_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_4_x} ＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the amount of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_3_x} 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

，

Converter station S ₂ Amount of faulty measures

。

5. A system for obtaining a soft dc grid dc single pole line fault measure quantity, the system comprising:

determining a topological structure module, and determining a topological structure of the safety control system of the flexible direct current power grid;

the data acquisition module is used for acquiring the calculation data of the fault measure quantity of the direct-current single-pole line of the safety control system of the flexible direct-current power grid according to the topological structure;

the calculation data comprises:

a converter station Si, where i is the ith converter station, i is 1, 2, 3, 4 … n;

variable of a converter Si _ P of the converter station Si positive electrode layer: maximum power P _{Smax_i_P} Operating power before failure P _{S0_i_P} Maximum band-rotating power quantity delta P _{S_i_P} And a valid bit V _{S_i_P} ；

Variable of a converter station Si cathode layer converter Si _ N: maximum power P _{Smax_i_N} Operating power before failure P _{S0_i_N} Maximum band-rotating power quantity delta P _{S_i_N} And V _{S_i_N} A valid bit;

a line Li, where i is the ith dc transmission line, and i is 1, 2, 3, 4 … n;

variable of transmission line Li _ P of Li positive electrode layer of line: maximum power P _{Lmax_i_P} Initial operating power P _{L0_i_P} And a valid bit V _{L_i_P} ；

Variable of transmission line Li _ N on Li negative pole layer of line: maximum power P _{Lmax_i_N} Initial operating power P _{L0_i_N} And a valid bit V _{L_i_N} ；

The variable operation of the converter station Si is set to be 1, and the exit is set to be 0;

the method comprises the steps that a variable module is obtained, and a variable is calculated according to the current converter blocking fault definition direct-current single-pole line fault measure quantity of the safety control system of the flexible direct-current power grid;

and the fault measure quantity obtaining module is used for obtaining the fault measure quantity of the direct current unipolar line according to the calculation data and the calculation variable.

6. The system of claim 5, wherein the grid-based flexible safety control system topology comprises: the flexible direct-current power grid security control system is of a true bipolar topological structure and the flexible direct-current power grid security control system is of a true unipolar topological structure.

7. The system of claim 5, said defined computational variables comprising:

the unbalanced power of the system is delta P;

maximum strip power of inverter of non-fault electrode layer is delta P' _{S_i_max} Wherein is Δ P' _{S_i_max} ＝ΔP _{S_i_x′} ＝V _{S_i_x′} ×(P _{Smax_i_x′} -P _{S0_i_x′} )；

The maximum strip power of the non-fault electrode layer is delta P' _∑maxM Wherein is Δ P' _∑maxM ＝V _{S_3_x′} ×(P _{Smax_3_x′} -P _{S0_3_x′} )+V _{S_4_x′} ×(P _{Smax_4_x′} -P _{S0_4_x′} )；

The maximum strip power of a non-fault electrode layer line is delta P' _∑maxL Wherein is Δ P' _∑maxL ＝V _{L_1_x′} ×(P _{Lmax_i_P} -P _{L0_1_x′} )+V _{L_2_x′} ×(P _{Lmax_i_P} -P _{L0_2_x′} )；

System transferable band power is delta P _trans In which Δ P _trans ＝min{ΔP’ _{S_i_max} ，ΔP’ _∑maxM ，ΔP’ _∑maxL }；

Amount of faulty measure P _trip ＝ΔP-ΔP _trans 。

8. The system of claim 7, wherein said calculating the quantity of the faulty measure based on the calculated data and the calculated variables comprises:

if the line L is _i Failure, then its V _{L_i_x} From 1 to 0;

recording the line-in-operation number K ═ V _{L_1_x} +V _{L_2_x} +V _{L_3_x} +V _{L_4_x} ；

When K is 3;

when V is _{L_1_x} +V _{L_2_x} 1 and P _{L0_1_P} +P _{L0_2_P} ＞P _{Lmax_i_P} Then the amount of faulty measure P _trip ＝P _{L0_1_P} +P _{L0_2_P} -P _{Lmax_i_P} -ΔP _trans ；

When K is 2;

when V is _{L_1_x} +V _{L_2_x} When equal to 0, V _{S_1_x} +V _{S_2_x} 2 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

When V is _{L_3_x} +V _{L_4_x} When the average value is equal to 0, the alloy,

V _{S_1_x} +V _{S_3_x} ＝1、V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ，

V _{S_2_x} +V _{S_4_x} ＝1、V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The amount of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_1_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_4_x} ＝0、P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans the amount of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans ；

V _{S_4_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_4_x} Δ P > 0 and Δ P _trans If delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

When V is _{L_1_x} +V _{L_3_x} When the average value is equal to 0, the alloy,

V _{S_1_x} 1 and P _{S0_1_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_3_x} When the content is equal to 0, the content,

V _{S_2_x} 1 and P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_2_x} -ΔP _trans ；

When V is _{L_2_x} +V _{L_4_x} When the content is equal to 0, the content,

V _{S_3_x} 0 and P _{S0_1_x} +P _{S0_2_x} ＞ΔP _trans The quantity of faulty measure P _trip ＝P _{S0_1_x} +P _{S0_2_x} -ΔP _trans

V _{S_3_x} ＝1、ΔP＝P _{S0_1_x} +P _{S0_2_x} -P _{Smax_3_x} Δ P > 0 and Δ P _trans Delta P is less than or equal to converter station S ₁ Amount of faulty measures

Converter station S ₂ Amount of faulty measures

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