CN109038594B - A kind of analysis method and system for load shedding fixed value of stability control device - Google Patents

Abstract

The invention discloses a method and a system for analyzing the load shedding fixed value of a stability control device. The method includes the steps of: selecting a key site for load shedding error prevention criteria, and determining the operation mode and fault type that need to be studied for the key site; determining the load Calculate the number of sections, and give the upper and lower limits of each load section, calculate the minimum load shedding required to maintain stability after the selected fault with different downfeed powers; The setting scheme is comprehensively considered, and the base value and the cut-off coefficient are optimized and adjusted to obtain the final setting scheme; when the power grid fails, the system can operate correctly and cut off the load as little as possible. After the state changes, it can be easily given to meet the needs new value.

Description

A kind of analysis method and system for load shedding fixed value of stability control device

technical field

The invention relates to the field of power system relay protection, in particular to an analysis method and system for load-shedding fixed value of a stability control device.

Background technique

With the interconnection of the power grid, the scale of the power system is increasing, and the possible stability problems are also increasing. In the actual operation of the power system, N-2 faults may be encountered, and some of them will lead to serious consequences. Stability control technology needs to be used to ensure the stability of the system. The core of the stability control technology is the stability control device.

The stability control device can act to cut off the load or unit under abnormal conditions to ensure the stability of the system, and has the advantages of strong pertinence and high reliability. However, its role depends to a large extent on reasonable set value tuning, and there is no systematic load shedding set value tuning method at present. A lot of work is done again to get the new setting.

SUMMARY OF THE INVENTION

The technical problem to be solved by the embodiments of the present invention is to provide a method and system for analyzing the load shedding value of a stability control device. When a fault occurs, the system applying the method can operate correctly and cut off the load as little as possible. After the change, the new setting that meets the needs can be easily given.

The technical problem to be solved by the present invention is realized by the following technical solutions:

A method for analyzing the load-shedding fixed value of a stability control device, comprising the following steps:

Select the typical operation mode of the power grid, simulate the expected faults, analyze the prominent sites with low voltage problems, select the key sites for load shedding error prevention criteria, and determine the operation mode and fault type that need to be studied for the key sites, and then determine the selected key points. The upper and lower limit power of its load section;

On the basis of the operation mode to be studied, gradually reduce the power delivered by key stations until the system is stabilized after the selected fault. Based on this, the number of load sections is determined, and the upper and lower power limits of each load section are given, and the simulation software is used. , calculate the minimum load shedding required to maintain stability after the selected fault occurs under each delivery power;

According to the load shedding value required for failure when the down-transmission power is at the upper and lower limit power of each load section, the base value and the cut-off coefficient are solved, and the preliminary tuning scheme is given. Optimize the adjustment to get the final tuning scheme.

Preferably, the voltage at the time of the selected fault in the key site check is lower than 0.75p.u. for no more than 1s during the transient process, and the recovery voltage should be above 0.90p.u., where p.u.=actual voltage value/reference voltage value . Dimensionless, in which the reference value can be selected from the nominal voltage of the grid or the average voltage of the grid. For example: when the nominal voltage is used as the reference value, if p.u.=1, it means that the actual voltage value is equal to the nominal voltage of the grid, that is, the actual value=reference value×p.u. value.

表示向下取整。Preliminarily, the removal coefficient k0 is initially calculated, k0=(Lmax-Lmin)/(Pmax-Pmin), where Pmax is the upper limit of the power in the load section of the key site, Lmax is the minimum load shedding amount corresponding to Pmax, and Pmin is the lower limit of the power in the load section. , Lmin is the minimum load shedding amount corresponding to Pmin; optimize the removal coefficient k, k=min(max(k0, 0.8), 1.2); calculate the base value Pbase,

Indicates rounded down.

否则

First, the optimized cut-off coefficient adjustment, kp=sum(ki)/n, where kp is the average cut-off coefficient, ki is the optimized cut-off coefficient of each load section, n is the number of load sections, and kp is adjusted from 0.8 to 0.8 according to the closest principle. One of 1.2, the interval is 0.1; base value adjustment, if k0>kp, then

otherwise

An analysis system for load-shedding fixed value of a stability control device, comprising:

The selection module is used to analyze the prominent sites with low voltage problems, select the key sites for load shedding and misjudgment prevention, and determine the operation modes and fault types that need to be studied for the key sites. lower limit power;

The load processing module is used to determine the number of load sections, and to give the upper and lower power limits of each load section, and to calculate the minimum load shedding required to maintain stability even after the selected fault occurs with different down-delivery powers;

The analysis and calculation module is used to solve the base value and cut-off coefficient according to the relationship between the upper and lower limit power of the load section and the corresponding minimum required load cut amount, and to give a preliminary setting scheme. Considering the whole setting scheme, the base value and The cutting coefficient is optimized and adjusted to obtain the final tuning scheme.

The implementation of this scheme has the following beneficial effects: the present invention analyzes the sites with prominent low voltage problems and selects key sites, determines the operation mode and fault type that need to be studied for the key sites, and then determines the upper and lower limit power of the load section for the selected key sites. The number of load sections and the required minimum load shedding amount corresponding to different powers; finally, according to the relationship between the upper and lower limit power of the load section and the corresponding minimum required load shedding amount, the shedding coefficient and base value are initially calculated, and then the entire tuning scheme is synthesized. Consider, optimize and adjust the base value and cut-off coefficient to obtain the final tuning scheme. When a fault occurs, the system applying this method can operate correctly and remove the load as little as possible, and can conveniently give a new set value that meets the needs after the system state changes.

Description of drawings

FIG. 1 is a schematic flowchart of an embodiment of an analysis method for a load-shedding fixed value of a stability control device according to the present invention;

Fig. 2 is the system voltage response curve under no load shedding strategy when the power delivered by the key site is 3300MW in the embodiment;

Fig. 3 is the system voltage response curve under no load shedding strategy when the power delivered by the key site is 3100MW in the embodiment;

Fig. 4 is the system voltage response curve under no load shedding strategy when the power delivered by the key site is 2900MW in the embodiment;

Fig. 5 is the system voltage response curve under no load shedding strategy when the power delivered by the key site is 2700MW in the embodiment;

Fig. 6 is the system voltage response curve under the load shedding strategy when the key site delivers 3300MW of power in the embodiment;

Fig. 7 is the system voltage response curve under the load shedding strategy when the key site delivers 3100 MW of power in the embodiment;

Fig. 8 is the system voltage response curve under the load shedding strategy when the key site delivers 2900 MW of power in the embodiment;

FIG. 9 is a schematic diagram of a tuning result according to an embodiment provided by the analysis method of the load shedding setting of the stability control device according to the present invention.

Detailed ways

The specific implementation in this embodiment will be further described in detail below with reference to the accompanying drawings.

In the following description, firstly, the embodiment of the analysis method for the constant value of the load shedding of the stability control device will be described, and then the embodiment of the analysis system of the constant value of the load shedding of the stability control device will be described.

Referring to FIG. 1 , it is a schematic flow chart of an embodiment of the method for analyzing the load-shedding constant value of the stability control device according to the present invention.

As shown in Figure 1, the method for analyzing the load-shedding value of the stability control device in this embodiment includes the following steps:

Step S100: Select a typical operation mode of the power grid, simulate the expected fault, analyze the prominent sites with low voltage problems, select key sites for load shedding and error prevention criteria, and determine the operation mode and fault type that need to be studied for the key sites. The specific implementation is as follows.

Step S101: Analyze the main AC and DC transmission lines of the system according to each typical operation mode and power flow diagram of the power grid;

Step S102: Set up faults of different types and different regions for the above-mentioned lines, and perform N-2 time domain simulation on them, observe the voltage disturbance response curves of each substation, and select near the main AC and DC transmission sections of the power grid to truly reflect the transient stability of the system For important substations with special characteristics, the voltage of the substation is used as the load shedding anti-misjudgment criterion;

Step S103: Compare the load shedding amount when different operation modes face different faults, and determine the operation mode and fault type to be studied.

After inspection, under the operation modes of Guangdong North Dafa and Xia Dafa of China Southern Power Grid, there is a transient low voltage failure when the fault of Cong Bo N-2, Hua Cong N-2, Cong Mu N-2, and Mu Qi N-2 fault occur. The low voltage problem of a key site of 220kV is prominent, and its transmission power is closely related to the load shedding amount. Therefore, this key site is selected as the load shedding prevention misjudgment site. After comparison, the fault of slave N-2 in northern Guangdong requires the largest amount of load shedding. Therefore, the operation mode and fault type to be studied are northern Guangdong and slave N-2 faults respectively.

Step S200: On the basis of the operation mode to be studied, gradually reduce the power delivered by key sites until the system is stabilized after the selected fault. Based on this, the number of load sections is determined, and the upper and lower limits of each load section are given. The simulation software calculates the minimum load shedding required to maintain stability after the selected fault occurs under each transmission power. The specific implementation is as follows.

Step S201: Based on the operation mode to be studied, determine the maximum delivery power of the key sites in the current system, take the maximum delivery power or the maximum delivery power plus a certain margin as the upper limit of the power of the load section, and check the occurrence selection. Minimum required load shedding in case of failure;

Step S202: Gradually reduce the delivery power of key sites until the system can maintain stability without load shedding under the selected fault, and use the delivered power when no load shedding is required or the power is reduced by a certain amount as the lower power limit of the load segment;

Step S203: selecting an appropriate number of load stages based on the determined upper and lower limits of the load stage;

Step S204: Using the simulation software, calculate the minimum required load shedding amount required to maintain stability after the selected fault occurs under each delivery power.

The maximum downlink power of the Kapok station in Dafa mode in northern Guangdong is 3300MW, so the downlink power is gradually decreased from 3300MW until the system can be stabilized when there is a fault from Bo N-2 without load shedding strategy, and the downlink power at this time is as the lower limit of the load segment. Figure 2, Figure 3, Figure 4 and Figure 5 show the simulation of the key site after the failure of the slave N-2 when the power of the above key sites is 3300MW, 3100MW, 2900MW and 2700MW when there is no load shedding strategy, respectively. voltage curve. In Figure 2, after the fault is cleared for 1.0s, the voltage is 0.62p.u., lower than 0.75p.u., the system is unstable; in Figure 3, after the fault is cleared for 1.0s, the voltage is 0.68p.u., lower than 0.75p.u., the system is unstable; in Figure 4, the fault is cleared 1.0 After s, the voltage is 0.73p.u., lower than 0.75p.u., the system is unstable; in Figure 5, after the fault is cleared for 1.0s, the voltage is 0.84p.u., higher than 0.75p.u., and the recovery voltage is higher than 0.90p.u., the system is stable. Comparing it with the stability criterion, it can be seen that the system is unstable when the N-2 fault occurs when the transmission power of the above-mentioned key sites is 3300MW, 3100MW, and 2900MW, while the system is stable after the N-2 fault occurs when the transmission power is 2700MW. Therefore, the lower limit of the load section should be set to 2700MW, and the current maximum downlink power of the system is 3300MW. Considering the possibility of future growth, the upper limit is set to 3500MW, and the difference between the upper and lower limits of each section is 200MW.

The simulation software is used to calculate the load shedding amount of the slave N-2 fault when the power is different. The results are shown in Table 1. Figure 6, Figure 7 and Figure 8 show the system effect diagrams after load removal.

Table 1. The load shedding amount required to simulate the occurrence of slave N-2 faults with different downlink powers at key sites:

Downlink power stable situation load cut 3500MW Transient low voltage problem Need to cut load 900MW 3300MW Transient low voltage problem Need to cut load 770MW 3100MW Transient low voltage problem Need to cut load 510MW 2900MW Transient low voltage problem Need to cut load 230MW 2700MW Transient low voltage problem No load shedding required

In Figure 6, after the fault is cleared for 1.0s, the voltage is 0.83p.u., higher than 0.75p.u., and the recovery voltage is higher than 0.90p.u., indicating that the system is stable; Figure 7 shows that after the fault is cleared for 1.0s, the voltage is 0.83p.u., higher than 0.75p.u., and The recovery voltage is higher than 0.90p.u., indicating that the system is stable; Figure 8 shows that after the fault is cleared for 1.0s, the voltage is 0.81p.u., higher than 0.75p.u., and the recovery voltage is higher than 0.90p.u., indicating that the system is stable.

Step S300: According to the load shedding value required for failure when the down transmission power is at the upper and lower limits of each load section, and solve the base value and the cutoff coefficient, a preliminary tuning scheme is given, and then the entire tuning scheme is comprehensively considered, and the base value and cutoff The coefficients are optimized and adjusted to obtain the final tuning scheme, as follows.

Step S301: Preliminarily calculate the excision coefficient k0, k0=(Lmax-Lmin)/(Pmax-Pmin),

Among them, is the upper limit of the power of the load section of the key site, Lmax is the minimum load shedding amount corresponding to Pmax, Pmin is the lower limit of the load section power, and Lmin is the minimum load shedding amount corresponding to Pmin;

Optimized excision coefficient k, k=min(max(k0, 0.8), 1.2);

Calculate the base value Pbase,

Step S302: Adjust the optimized cut-off coefficient, determine whether the cut-off coefficient k is consistent, if different, calculate kp=sum(ki)/n, where kp is the average cut-off coefficient, ki is the optimized cut-off coefficient of each load segment, and n is The number of load segments, kp is adjusted to one of 0.8 to 1.2 according to the closest principle, and the interval is 0.1;

否则

Base value adjustment, if k0>kp, then

otherwise

According to the load shedding value required for the failure of the upper and lower limits of each load section of the above-mentioned key sites, the specific process of initially solving the base value and the shedding coefficient is as follows, and the results are shown in Table 2.

2700-2900: k0=(Lmax-Lmin)/(Pmax-Pmin)=(230-0)/200=1.15

k=min(max(k0, 0.8), 1.2)=1.15

2900-3100: k0=(Lmax-Lmin)/(Pmax-Pmin)=(510-230)/200=1.4

k=min(max(k0, 0.8), 1.2)=1.2

3100-3300: k0=(Lmax-Lmin)/(Pmax-Pmin)=(770-510)/200=1.3

k=min(max(k0, 0.8), 1.2)=1.2

3300-3500: k0=(Lmax-Lmin)/(Pmax-Pmin)=(900-770)/200=0.65

k=min(max(k0, 0.8), 1.2)=0.8

Table 2 Preliminary calculation of the base value and cut-off coefficient of each load segment at key sites:

load section Pbase k0 2700-2900 2700 1.15 2900-3100 2708 1.2 3100-3300 2675 1.2 3300-3500 2337 0.8

It can be seen from Table 2 that the initially calculated cut-off coefficients for each load section of the key station are different. The entire tuning scheme is considered as a whole, and the following optimization adjustments are made. The specific steps are as follows, and the results are shown in Table 2.

Average excision coefficient: kp=(1.15+1.2+1.2+0.8)/4=1.1 (after rounding)

2700-2900:

2900-3100:

3100-3300:

3300-3500:

Table 3. Base value and cut-off coefficient for optimization calculation of each load segment at key sites:

load section Pbase k 2700-2900 2690 1.1 2900-3100 2636 1.1 3100-3300 2600 1.1 3300-3500 2600 1.1

The base value and cut-off coefficient initially calculated for each load section of the key station, the base value after optimization calculation and the corresponding curve of cut-off coefficient scheme are drawn into the final overall effect diagram, see Figure 9. The black dots in the figure correspond to the minimum load to be cut under a given load, the blue dotted line is the preliminary setting result, and the red solid line is the final setting result after optimization. The blue dotted line can ensure that the load shedding amount meets the requirements when the given power is delivered, but when the actual delivered power value is not the given power, the following power is slightly reduced from 3300MW to 3299MW, and the system operation mode is basically unchanged at this time. , the load shedding amount will not be significantly reduced, but the load shedding amount of the blue demand line will be greatly reduced at this time, which may not meet the system stability requirements, but the final tuning scheme indicated by the red solid line is a better solution. solved this problem. In addition, different from the multiple k0 values in the preliminary tuning scheme, the k values of each segment of the final tuning scheme are basically the same, which effectively reduces the possibility of the setting personnel and the personnel performing the setting mistake filling in the k value of each segment.

The analysis system for the load shedding value of the stability control device in this embodiment includes the following steps:

Step S400: selecting a module for selecting key sites for load shedding error prevention criteria, and determining the operation modes and fault types that need to be studied for the key sites, as follows:

Step S401: an analysis unit, configured to analyze the main AC and DC transmission lines of the system according to various typical operation modes and power flow diagrams of the power grid;

Step S402: The first simulation unit is used to set faults of different types and different regions for the selected line, and perform N-2 time domain simulation on it, observe the voltage disturbance response curve of each substation, and observe the main AC and DC transmission sections of the power grid. Select an important substation nearby that truly reflects the transient stability characteristics of the system, and use the voltage of the substation as the load shedding error prevention criterion;

Step S403 : the comparison unit compares the amount of load shedding when different operating modes face different faults, and determines the operating mode and fault type to be studied.

Step S500: The load processing module is used to determine the number of load sections, and to give the upper and lower limits of each load section, and to calculate the minimum required load shedding amount required to maintain stability even after the selected fault occurs with different down power, the details are as follows:

Step S501: an upper limit power determination unit, configured to determine the upper limit of the maximum delivered power of key sites;

Step S502: The lower limit power determination unit is used to determine to gradually reduce the power delivered to key sites until the system can maintain stability without load shedding under the selected fault, so that the delivered power when no load shedding is not required or the power is reduced by a certain amount. The amount is used as the lower limit of the load section power;

Step S503: a unit for determining the number of load sections, for determining an appropriate number of load sections according to the upper and lower limits of the selected load sections;

Step S504: The second simulation unit is used to simulate and calculate the minimum required load shedding amount required to maintain stability after the selected fault occurs under different transmission powers.

Step S600: The analysis and calculation module is used to solve the base value and the cut-off coefficient, give a preliminary setting scheme, and consider the entire set-up scheme, optimize and adjust the base value and cut-off coefficient to obtain the final setting scheme, as follows:

Step S601: a preliminary scheme determination unit, used for preliminary determination of the excision coefficient and the base value;

Step S602: an optimization scheme determination unit for optimizing the excision coefficient and the base value.

The analysis system of the load shedding constant value of the stability control device of the present invention corresponds to the analysis method of the load shedding constant value of the stability control device of the present invention. The effects are all applicable to the embodiment of the analysis system of the load-shedding constant value of the stability control device, which is hereby declared.

The implementation of this scheme has the following beneficial effects: the present invention analyzes the sites with prominent low voltage problems and selects key sites, determines the operation mode and fault type that need to be studied for the key sites, and then determines the upper and lower limit power of the load section for the selected key sites. The number of load sections and the required minimum load shedding amount corresponding to different powers; finally, according to the relationship between the upper and lower limit power of the load section and the corresponding minimum required load shedding amount, the shedding coefficient and base value are initially calculated, and then the entire tuning scheme is synthesized. Consider, optimize and adjust the base value and cut-off coefficient to obtain the final tuning scheme. When a fault occurs, the system applying this method can operate correctly and remove the load as little as possible, and can conveniently give a new set value that meets the needs after the system state changes.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of implementation of the present invention. Any person of ordinary skill in the art can make some improvements without departing from the scope of the present invention, that is, all equivalent improvements made according to the present invention should be covered by the scope of the present invention.

Claims (10)

1. A method for analyzing a load shedding fixed value of a stability control device is characterized by comprising the following steps:

selecting a typical operation mode of a power grid, simulating an expected fault, analyzing a low-voltage problem highlighted site, selecting a key site of a load shedding anti-error criterion, determining an operation mode and a fault type of the key site to be researched, and then determining upper and lower limit powers of a load section of the selected key site;

on the basis of an operation mode to be researched, the descending power of the key station is gradually reduced until the system is stable after a selected fault, the number of load sections is determined on the basis of the descending power of the key station, the upper limit power and the lower limit power of each load section are given, and the minimum load cut required for keeping the stability after the selected fault occurs under each descending power is calculated by using simulation software;

according to the load shedding quantity value required by the fault when the lower power is at the upper limit power and the lower limit power of each load section, the base value and the shedding coefficient are solved, a primary setting scheme is given, then the whole setting scheme is comprehensively considered, and the base value and the shedding coefficient are optimized and adjusted to obtain a final setting scheme.

2. The method for analyzing the load shedding fixed value of the stability control device according to claim 1, wherein the step of selecting the key station of the load shedding anti-error criterion and determining the operation mode and the fault type of the key station to be researched comprises the following steps:

analyzing main alternating current and direct current transmission lines of the system according to each typical operation mode and a tidal current diagram of the power grid;

setting faults of different types and different regions aiming at the line, carrying out N-2 time domain simulation on the faults, observing voltage disturbance response curves of all substations, selecting an important substation which truly reflects the transient stability characteristic of the system near the main alternating current and direct current transmission section of the power grid, and taking the important substation as a load shedding error-preventing criterion;

and comparing the load shedding amount of different operation modes facing different faults, and determining the operation mode and the fault type to be researched.

3. The method for analyzing the load shedding fixed value of the stability control device according to claim 1, wherein the determining the number of the load segments and providing the upper and lower limit powers of each load segment comprises the following steps:

determining the maximum sending power of the key station of the current system based on the operation mode to be researched, taking the maximum sending power or the maximum sending power plus a certain margin as the upper limit of the power of a load section, and checking the minimum load to be cut when a selected fault occurs;

gradually reducing the sending power of the key station until the system can keep stable without load shedding under the selected fault, and taking the sending power when the load shedding is not needed or reducing the sending power by a certain amount as the lower limit of the power of the load section;

and selecting the proper number of the load sections based on the determined upper and lower limit powers of the load sections.

4. The method for analyzing the load shedding fixed value of the stability control device according to claim 3, wherein the judgment basis for the system to keep stable is as follows: the critical site checks that the voltage at the time of the selected fault is below 0.75p.u. for no more than 1s during the transient, and the recovery voltage should be above 0.90p.u., where p.u. = actual voltage value/reference voltage value.

5. The method for analyzing the fixed value of the cutting load of the stability and control device according to claim 1 or 3, wherein the step of solving the basic value and the cutting coefficient comprises the following steps:

preliminary calculation of the ablation coefficients k0, k0= (Lmax-Lmin)/(Pmax-Pmin),

wherein Pmax is the upper limit of the power of the load section of the key station, Lmax is the minimum load shedding amount corresponding to Pmax, Pmin is the lower limit of the power of the load section, and Lmin is the minimum load shedding amount corresponding to Pmin;

optimizing the ablation coefficient k, k = min (max (k0,0.8), 1.2);

the base value Pbase was calculated, Pbase = ⌊ Pmin-Lmin/k ⌋, ⌊ ⌋ indicating rounding down.

6. The method for analyzing the fixed value of the cutting load of the stability control device according to claim 5, wherein the optimization adjustment comprises the optimized adjustment of the cutting coefficient and the adjustment of the basic value, and the method comprises the following steps:

adjusting the optimized ablation coefficient, wherein kp = sum (ki)/n, wherein kp is the average ablation coefficient, ki is the optimized ablation coefficient of each load section, n is the number of load sections, kp is adjusted to be one of 0.8 to 1.2 according to the closest principle, and the interval is 0.1;

adjusting the basic value, if k0> kp, Pbase = ⌊ Pmax-Lmax/kp ⌋, otherwise Pbase = ⌊ Pmin-Lmin/kp ⌋.

7. A system for analyzing a load shedding fixed value of a stability control device is characterized by comprising:

the selection module is used for analyzing the low-voltage problem highlighted sites, selecting key sites of load shedding anti-error criteria, determining the operation mode and the fault type of the key sites to be researched, and then determining the upper limit power and the lower limit power of the load section of the selected key sites;

the load processing module is used for determining the number of the load sections, giving the upper and lower limit power of each load section, and calculating the minimum load to be cut for keeping stable after the selected faults occur to different downlink powers;

and the analysis and calculation module is used for solving the base value and the cutting coefficient according to the relation between the upper limit power and the lower limit power of the load section and the corresponding minimum load needing to be cut, giving a primary setting scheme, and optimizing and adjusting the base value and the cutting coefficient according to the whole setting scheme to obtain a final setting scheme.

8. The system for analyzing the load shedding fixed value of the stability control device according to claim 7, wherein the selecting module comprises:

the analysis unit is used for analyzing main alternating current and direct current transmission lines of the system according to each typical operation mode and tidal current diagram of the power grid;

the first simulation unit is used for setting faults of different types and different regions aiming at a selected line, carrying out N-2 time domain simulation on the faults, observing voltage disturbance response curves of all substations, selecting an important substation which truly reflects the transient stability characteristic of the system near main alternating current and direct current transmission sections of a power grid, and taking the important substation as a load shedding error prevention criterion;

and the comparison unit is used for comparing the load shedding amount of different operation modes facing different faults and determining the operation mode and the fault type to be researched.

9. The system for analyzing the load shedding constant value of the stability control device according to claim 7, wherein the load processing module comprises:

the upper limit power determining unit is used for determining the maximum lower power upper limit of the key station;

the lower limit power determining unit is used for determining to gradually reduce the downlink power of the key station until the system can keep stable without load shedding under the selected fault, and the downlink power when the load shedding is not needed or the downlink power is reduced by a certain amount to be used as the lower limit of the power of the load section;

the load segment number determining unit is used for determining the appropriate number of load segments according to the upper and lower limit power of the selected load segments;

and the second simulation unit is used for simulating and calculating the minimum load required to be cut for keeping stability after the selected fault occurs under different sending powers.

10. The system for analyzing the load shedding fixed value of the stability control device according to claim 7, wherein the analyzing and calculating module comprises:

a preliminary scheme determination unit for preliminarily determining the resection coefficient and the base value;

and the optimization scheme determination unit is used for optimizing the excision coefficient and the base value.

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