Method and device for comprehensively evaluating effect of energy storage converter participating in reactive power regulation of power grid, electronic equipment and storage medium

Abstract

The invention discloses a comprehensive evaluation method and device for the effect of an energy storage converter participating in reactive power regulation of a power grid, electronic equipment and a storage medium, and belongs to the technical field of operation control of a power system, and the method comprises the steps: determining a typical operation scene in which the energy storage converter participates in reactive power regulation; determining reactive power regulation variables of the energy storage converter in different scenes; quantizing the voltage regulation effect and the power factor increasing effect of the energy storage converter participating in reactive power regulation in different scenes; and evaluating the comprehensive effect of the energy storage converter participating in reactive power regulation. According to the method, the reactive power regulation capability of the energy storage converter in different scenes and the influence of the power grid voltage, the power factor and the line loss change are comprehensively considered. According to the method, through multi-dimensional quantitative index evaluation, the comprehensive effect of the energy storage converter in the aspect of improving the operation efficiency of the power grid can be accurately reflected, so that the accuracy and comprehensiveness of reactive power regulation effect evaluation are further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system operation control, and specifically relates to a method, device, electronic equipment and storage medium for comprehensively evaluating the effect of an energy storage converter participating in reactive power regulation of a power grid. Background Art

[0002] At present, new energy sources have been connected to the power grid on a large scale. The reactive power regulation capabilities of wind power and photovoltaic power generation units are significantly weaker than those of conventional thermal power and hydropower. The reactive power regulation capabilities of the entire power grid are insufficient, and problems such as voltage over-limit, surge in line loss, and decreased power factor have occurred. It is urgent to increase reactive power sources to improve the reactive power regulation capabilities of the power grid. With the rapid development of energy storage technology, energy storage converters have reactive power regulation capabilities while charging and discharging active power, and can be used as a reactive power source. However, the reactive power regulation effect of energy storage converters is affected by multiple factors such as the operating status of the power grid and load fluctuations, making it difficult to accurately evaluate the reactive power regulation effect. Summary of the invention

[0003] In view of the above-mentioned problems existing in the prior art, the present invention proposes a comprehensive evaluation method, device, electronic equipment and storage medium for the effect of energy storage converter participating in reactive power regulation of the power grid. The method, device, electronic equipment and storage medium are reasonably designed to solve the problem that the reactive power regulation effect of energy storage converter is difficult to be quantified accurately in the prior art, and the method has good results.

[0004] A comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid comprises the following sub-steps:

[0005] Determine the typical operating scenarios of energy storage converters participating in reactive power regulation;

[0006] Determine the reactive power regulation of the energy storage converter under different typical operating scenarios;

[0007] Based on the reactive power regulation of energy storage converters in different typical operating scenarios, the loss reduction effect, voltage regulation effect and power factor improvement effect of energy storage converters participating in reactive power regulation in different typical operating scenarios are quantified;

[0008] Based on the quantified loss reduction effect, voltage regulation effect and power factor improvement effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios, the comprehensive effect of the energy storage converter participating in reactive power regulation is evaluated.

[0009] Furthermore, determining a typical operation scenario in which the energy storage converter participates in reactive power regulation includes the following sub-steps:

[0010] Step 1.1: Collect typical daily power generation data of renewable energy in the region to be evaluated, with a step length of T minutes, to form a power generation data set {P W1 ,P W2 ,…,P Wt ,…,,P W(1440 / T)}, where P Wt is the t-th power generation; at the same time, the typical daily data of load power consumption in the area to be evaluated is collected, with a step length of T minutes, to form a load power consumption data set {P L1 ,P L2 ,…,P Lt ,,P L(1440 / T)}, where P Lt is the power consumption of the tth load;

[0011] Step 1.2: Calculate the difference between the power generated by renewable energy and the power consumed by the load, and take max{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 1, when the photovoltaic power generation is large and the load is small; take min{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 2, when the photovoltaic power generation is not performed and the load is large.

[0012] Furthermore, determining the reactive power regulation amount of the energy storage converter under different typical operation scenarios includes the following sub-steps:

[0013] Step 2.1: Based on the actual power grid data of the area to be evaluated, build a power grid containing new energy in the power system simulation analysis software, with the number of nodes N, and calculate the voltage value u of each node under each typical operation scenario i ij , where i is the typical operation scenario number and j is the node number; and calculate the voltage average value u in the i-th typical operation scenario vi ,in

[0014] Step 2.2: The calculated average voltage value u vi With rated voltage U N Compare and calculate the voltage deviation: Δu vi =u vi -U N ; When Δu vi >0, the voltage of the i-th typical operation scenario is too high, and the energy storage converter should gradually absorb reactive power; when Δu vi When <0, the grid voltage of the i-th typical operation scenario is low, and the energy storage converter should gradually generate reactive power;

[0015] Step 2.3: Count the number of energy storage converters K and the reactive power regulation range of the kth converter {Q min,k ,Q max,k}, when Δuvi>0, select the adjustment step From 0 to Q min,k Increase the reactive absorption in sequence; when Δu vi <0, select adjustment step From 0 to Qmax,k Increase the reactive power output in sequence; α and β are the grading coefficients, which are positive integers.

[0016] Furthermore, quantifying the loss reduction effect of energy storage converters participating in reactive power regulation under different typical operating scenarios includes the following sub-steps:

[0017] Step 3.1: Based on the power grid built in step 2.1, perform power flow calculations under different typical operating scenarios to obtain the line loss baseline value when the energy storage converter is not connected to reactive power regulation, denoted as P loss,i,before ;

[0018] Step 3.2: According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k As interval, the reactive absorption of each energy storage converter is increased in sequence, and simulation calculations are performed for α times. The calculated line loss is recorded as When Δu vi When ΔQ k As interval, the reactive power output of each energy storage converter is increased in sequence, and β simulation calculations are performed. The calculated line loss is recorded as

[0019] Step 3.3: In any simulation calculation of step 3.2, the line loss reduction effect of the energy storage converter on the line loss is quantified by the line loss baseline value and the line loss reduction rate. The specific formula is:

[0020]

[0021] Among them, m=1,...,α, n=1,...,β; represents the line loss value of the mth simulation in the αth simulation of the i-th typical operation scenario, η m loss,i represents the loss reduction rate of the mth simulation; represents the line loss value of the nth simulation in the βth simulation of the i-th typical operation scenario, η n loss,i Represents the loss reduction rate of the nth simulation.

[0022] Furthermore, quantifying the voltage regulation effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios includes the following sub-steps:

[0023] Step 4.1: Based on the power grid built in step 2.1, according to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive absorption of each energy storage converter is increased in turn and the power flow simulation calculation is performed for α times. The voltage of each node is recorded as When Δuvi When ΔQ k The reactive power output of each energy storage converter is increased at intervals, and the β-time power flow simulation calculation is performed. The voltage of each node is recorded as

[0024] The voltage deviation of each node voltage after the reactive output adjustment of the energy storage converter is obtained. The specific formula is:

[0025]

[0026] Among them, u i,j α,m represents the voltage of each node in the mth simulation, Δu i,j m Indicates u i,j α,m Voltage deviation, u i,j β,n represents the voltage of each node in the nth simulation, Δu i,j n Indicates u i,j β,n Voltage deviation;

[0027] Step 4.2: For each reactive power regulation, the voltage regulation effect of the energy storage converter is quantified by calculating the average voltage deviation. The specific formula is:

[0028]

[0029] in, represents the average voltage deviation of the mth simulation in α, It represents the average voltage deviation of the nth time in the β simulation.

[0030] Furthermore, the power factor improvement effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios is quantified, including the following sub-steps:

[0031] Step 5.1: Based on the power grid built in step 2.1, perform power flow calculation and record the power factor reference value cosθ of monitoring point A before the energy storage converter is connected i,before The grid is connected to the energy storage converter. According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive power absorption of each converter is increased at intervals, and simulation calculations are performed for α times. The power factors are recorded as When Δu vi When ΔQ k The reactive power output of each converter is increased at intervals, and β simulation calculations are performed. The power factors are recorded as

[0032] Step 5.2: For each reactive power regulation, the effect of the energy storage converter on the power factor improvement is quantified by the power factor baseline value and the relative power factor improvement calculated by the power factor. The specific formula is:

[0033]

[0034] Among them, cosθ i,after α,m represents the mth power factor in the α simulation, Δcosθ i m represents cosθ i,after α,m The amount of improvement; cosθ i,after β,n represents the nth power factor in the β simulation, Δcosθ i n represents cosθ i,after β,n The amount of improvement.

[0035] Furthermore, the comprehensive effect of the energy storage converter participating in reactive power regulation is evaluated, including the following sub-steps:

[0036] Step 6.1: Use the maximum and minimum standardization method to normalize the indicators of the loss reduction effect, voltage regulation effect and power factor improvement effect of the quantified energy storage converter participating in reactive power regulation to the same scale, and the standardized value range is 0 to 1;

[0037] The standardized processing formula for each reactive regulation quantity in the i-th typical operation scenario is as follows:

[0038] Standardization of loss reduction effects:

[0039]

[0040] The normalized result of the voltage regulation effect is negated:

[0041]

[0042] Standardization of power factor improvement effect:

[0043]

[0044] Step 6.2: Assign weights, and then obtain the comprehensive score for each reactive power regulation quantity by weighted summation. The calculation formula for the comprehensive score is:

[0045]

[0046] Among them, z η 、zΔu 、z Δcosθ They are the weights of loss reduction effect, voltage regulation effect and power factor improvement effect, which are set according to actual needs; S i m is the comprehensive score of the mth reactive regulation quantity under the ith typical operation scenario; S i n It is the comprehensive score of the nth reactive power regulation quantity in the ith typical operation scenario.

[0047] A comprehensive evaluation device for the effect of energy storage converter participating in reactive power regulation of power grid, the device comprising:

[0048] A scenario determination module, used to determine a typical operation scenario in which the energy storage converter participates in reactive power regulation;

[0049] A quantification module is used to quantify the effect of the energy storage converter participating in reactive power regulation under different typical operation scenarios based on the reactive power regulation amount of the energy storage converter under different typical operation scenarios;

[0050] The evaluation module is used to evaluate the comprehensive effect of the energy storage converter participating in reactive power regulation based on the quantified effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios.

[0051] Furthermore, in the quantification module, the effects of the energy storage converter participating in reactive power regulation under different typical operating scenarios are quantified, including loss reduction effect, voltage regulation effect and power factor improvement effect.

[0052] An electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the above-mentioned comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid.

[0053] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid.

[0054] Beneficial technical effects brought by the present invention:

[0055] The present invention proposes a comprehensive evaluation method for the effect of energy storage converters participating in reactive power regulation of power grids, which comprehensively considers the reactive power regulation capability of energy storage converters in different scenarios, as well as the influence of changes in grid voltage, power factor and line loss. This method can accurately reflect the comprehensive effect of energy storage converters in improving grid operation efficiency through multi-dimensional quantitative index evaluation, thereby further improving the accuracy and comprehensiveness of reactive power regulation effect evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1A flow chart of a method for comprehensively evaluating the effect of an energy storage converter participating in reactive power regulation of a power grid in the present invention;

[0057] Figure 2 It is a curve diagram of photovoltaic power generation and load power consumption in the present invention;

[0058] Figure 3 This is a schematic diagram of an active power grid to which a typical energy storage converter is connected in the present invention. DETAILED DESCRIPTION

[0059] The specific implementation of the present invention is further described below in conjunction with specific embodiments:

[0060] A comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid, such as Figure 1 As shown, it includes the following sub-steps:

[0061] Step 1: Determine the typical operating scenario of the energy storage converter participating in reactive power regulation, including the following sub-steps:

[0062] Step 1.1: Construct a data set of renewable energy generation and load electricity consumption; specifically:

[0063] Collect typical daily power generation data of renewable energy in the area to be evaluated, with a step length of T minutes, to form a power generation data set {P W1 ,P W2 ,…,P Wt ,,P W(1440 / T) At the same time, the typical daily data of load power consumption in the area to be evaluated is collected, with a step length of T minutes, to form a power load data set {P L1 ,P L2 ,…,P Lt ,,P L(1440 / T)}, where P Lt is the power consumption of the tth load;

[0064] Step 1.2: Divide typical scenarios based on renewable energy power generation and load power consumption data; specifically:

[0065] Calculate the difference between the power generated by renewable energy and the power consumed by the load, and take max{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 1, when the photovoltaic power generation is large and the load is small; take min{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 2, when the photovoltaic power generation is not performed and the load is large.

[0066] Step 2: Determine the reactive power regulation of the energy storage converter under different typical operating scenarios, including the following sub-steps:

[0067] Step 2.1: Simulate the average voltage under different operating scenarios; specifically:

[0068] Based on the actual power grid data of the area to be evaluated, a power grid containing new energy is built in the power system simulation analysis software. The number of nodes is N. The voltage value u of each node is calculated under each typical operation scenario i. ij , where i is the typical operation scenario number and j is the node number; and calculate the voltage average value u in the i-th typical operation scenario vi ,in

[0069] Step 2.2: Based on the voltage deviation between the average voltage and the rated voltage, determine the reactive power regulation direction of the converter under different typical operating scenarios; specifically:

[0070] The calculated average voltage value u vi With rated voltage U N Compare and calculate the voltage deviation: Δu vi =u vi -U N ; When Δu vi >0, the voltage of the i-th typical operation scenario is too high, and the energy storage converter should gradually absorb reactive power; when Δu vi When <0, the grid voltage of the i-th typical operation scenario is low, and the energy storage converter should gradually generate reactive power;

[0071] Step 2.3: Determine the reactive power regulation amount of the converter under different typical operation scenarios based on the reactive power regulation direction; specifically:

[0072] Count the number of energy storage converters K and the reactive power regulation range of the kth converter {Q min,k ,Q max,k}, when Δuvi>0, select the adjustment step From 0 to Q min,k Increase the reactive absorption in sequence; when Δu vi <0, select adjustment step From 0 to Q max,k Increase the reactive power output in sequence; α and β are the grading coefficients, which are positive integers.

[0073] Step 3: Based on the reactive power regulation of the energy storage converter under different typical operating scenarios, quantify the loss reduction effect, voltage regulation effect and power factor improvement effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios, including the following sub-steps:

[0074] Step 3.1: Based on the power grid built in step 2.1, perform power flow calculations under different typical operating scenarios to obtain the line loss baseline value when the energy storage converter is not connected to reactive power regulation, denoted as P loss,i,before ;

[0075] Step 3.2: According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k As interval, the reactive absorption of each energy storage converter is increased in sequence, and simulation calculations are performed for α times. The calculated line loss is recorded as When Δu vi When ΔQ k As interval, the reactive power output of each energy storage converter is increased in sequence, and β simulation calculations are performed. The calculated line loss is recorded as

[0076] Step 3.3: In any simulation calculation of step 3.2, the line loss reduction effect of the energy storage converter on the line loss is quantified by the line loss baseline value and the line loss reduction rate. The specific formula is:

[0077]

[0078] Among them, m=1,...,α, n=1,...,β; represents the line loss value of the mth simulation in the αth simulation of the i-th typical operation scenario, η m loss,i represents the loss reduction rate of the mth simulation; represents the line loss value of the nth simulation in the βth simulation of the i-th typical operation scenario, η n loss,i Represents the loss reduction rate of the nth simulation.

[0079] Quantifying the voltage regulation effect of energy storage converters participating in reactive power regulation under different typical operating scenarios includes the following sub-steps:

[0080] Step 4.1: Based on the power grid built in step 2.1, perform power flow calculations in different typical operation scenarios to obtain node voltages; specifically:

[0081] According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive absorption of each energy storage converter is increased in turn and the power flow simulation calculation is performed for α times. The voltage of each node is recorded as When Δu vi When ΔQ k The reactive power output of each energy storage converter is increased at intervals, and the β-time power flow simulation calculation is performed. The voltage of each node is recorded as

[0082] The voltage deviation of each node voltage after the reactive output adjustment of the energy storage converter is obtained. The specific formula is:

[0083]

[0084] Among them, u i,j α,m represents the voltage of each node in the mth simulation, Δu i,j α,m Indicates u i,j α,m Voltage deviation, u i,j β,n represents the voltage of each node in the nth simulation, Δu i,j β,n Indicates u i,j β,n Voltage deviation;

[0085] Step 4.2: For each reactive power regulation, the voltage regulation effect of the energy storage converter is quantified by calculating the average voltage deviation. The specific formula is:

[0086]

[0087] in, represents the average voltage deviation of the mth simulation in α, It represents the average voltage deviation of the nth time in the β simulation.

[0088] Quantify the power factor improvement effect of energy storage converters participating in reactive power regulation under different typical operating scenarios, including the following sub-steps:

[0089] Step 5.1: Based on the power grid built in step 2.1, perform power flow calculation and record the power factor reference value cosθ of monitoring point A before the energy storage converter is connected i,before The grid is connected to the energy storage converter, and the power flow calculation is performed under different typical operation scenarios; specifically:

[0090] According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive power absorption of each converter is increased at intervals, and simulation calculations are performed for α times. The power factors are recorded as When Δu vi When ΔQ k The reactive power output of each converter is increased at intervals, and β simulation calculations are performed. The power factors are recorded as

[0091] Step 5.2: For each reactive power regulation, the effect of the energy storage converter on the power factor improvement is quantified by the power factor baseline value and the relative power factor improvement calculated by the power factor. The specific formula is:

[0092]

[0093] Among them, cosθ i,after α,m represents the mth power factor in the α simulation, Δcosθ i m represents cosθ i,after α,m The amount of improvement; cosθ i,after β,n represents the nth power factor in the β simulation, Δcosθ i n represents cosθ i,after β,n The amount of improvement.

[0094] Step 6: Based on the quantified loss reduction effect, voltage regulation effect and power factor improvement effect of the energy storage converter in reactive power regulation under different typical operating scenarios, the comprehensive effect of the energy storage converter in reactive power regulation is evaluated, including the following sub-steps:

[0095] Step 6.1: Use the maximum and minimum standardization method to normalize the indicators in step 3 to the same scale. The standardized value range is 0 to 1. The larger the value, the better the effect.

[0096] The standardized processing formula for each reactive regulation quantity in the i-th typical operation scenario is as follows:

[0097] Standardization of loss reduction effects:

[0098]

[0099] The standardized result of the voltage regulation effect is reversed, because the smaller the voltage deviation value, the better the effect:

[0100]

[0101] Standardization of power factor improvement effect:

[0102]

[0103] Step 6.2: Assign weights, and then obtain the comprehensive score for each reactive power regulation quantity by weighted summation. The calculation formula for the comprehensive score is:

[0104]

[0105] Among them, z η 、z Δu 、z Δcosθ They are the weights of loss reduction effect, voltage regulation effect and power factor improvement effect, which are set according to actual needs; S i mis the comprehensive score of the mth reactive regulation quantity under the ith typical operation scenario; S i n It is the comprehensive score of the nth reactive power regulation quantity under the ith typical operation scenario. The mth reactive power regulation quantity corresponds to the mth simulation, and the nth reactive power regulation quantity corresponds to the nth simulation.

[0106] A comprehensive evaluation device for the effect of energy storage converter participating in reactive power regulation of power grid, the device comprising:

[0107] A scenario determination module, used to determine a typical operation scenario in which the energy storage converter participates in reactive power regulation;

[0108] A quantification module is used to quantify the effect of the energy storage converter participating in reactive power regulation under different typical operation scenarios based on the reactive power regulation amount of the energy storage converter under different typical operation scenarios;

[0109] The evaluation module is used to evaluate the comprehensive effect of the energy storage converter participating in reactive power regulation based on the quantified loss reduction effect, voltage regulation effect and power factor improvement effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios.

[0110] An electronic device includes a memory and a processor. The memory stores a computer program. The processor executes the computer program to implement the above-mentioned comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid.

[0111] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid.

[0112] Example 1

[0113] A comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid, comprising:

[0114] Step 1: Determine the typical operating scenario of the energy storage converter participating in reactive power regulation, including the following sub-steps:

[0115] Step 1.1: Collect typical daily power generation data of renewable energy in the region to be evaluated. The renewable energy generation in the region is mainly photovoltaic power generation. With a step length of 15 minutes, 96 data are obtained to form a data set {P W1 ,P W2 ,P W3 …P W96 At the same time, the typical daily data of load power consumption in the area to be evaluated is collected, with a step length of 15 minutes, and 96 data are obtained to form a load data set {P L1 ,P L2 ,P L3 …P L96}; Draw the photovoltaic power generation and load power curves as follows Figure 2 shown.

[0116] Step 1.2: Divide typical scenarios based on renewable energy power generation and load power consumption data; Analyze the data collected above. Within 24 hours, the changes in photovoltaic power generation and grid load show obvious time patterns, and there is a certain mismatch between the changes in the two, especially in the high-load period and the high-production period of photovoltaic power generation. Calculate the difference between renewable energy power generation and load power consumption based on the obtained data. When t = 14:30 is taken as the typical operation scenario 1, the difference is the largest at this time, max{P Wt -P Lt}=6000-1050=4950(kW). When t=20:30, it is the typical operation scenario 2, and the difference is the smallest, min{P Wt -P Lt}=0-2940=-2940(kW).

[0117] Typical operation scenario 1: PV power generation + light load scenario, which usually occurs during the noon period during the day, when PV power generation reaches its maximum value and grid load is relatively low. This may lead to problems such as excess power, reverse power flow, increased node voltage, and decreased power factor.

[0118] Typical operation scenario 2: No PV + heavy load scenario, this scenario usually occurs in the evening to night, when the grid load reaches its maximum value, while PV power generation is almost zero. Since PV power generation is low or even zero, the grid needs to rely on remote power generation to meet load demand, resulting in increased line losses in long-distance transmission, and the voltage and power factor are also prone to decline.

[0119] These two scenarios represent two extreme conditions of the power grid in terms of photovoltaic power generation and load changes. Choosing them as typical scenarios for research will help to fully cover the main operating states of the power grid in different time periods and comprehensively examine the performance of energy storage inverters in dealing with challenges in power grid operation.

[0120] Step 2: Determine the reactive power regulation of the energy storage converter under different typical operating scenarios, including:

[0121] Step 2.1: Based on the actual power grid data of a certain region collected in step 1, an IEEE 33-node power grid containing new energy is constructed in the power system simulation analysis software, with the number of nodes being N = 33. Figure 3 As shown, the load is distributed on each node except node 1. The distribution of light / heavy load on each node is shown in Table 1;

[0122] Table 1: Light and heavy load access situation

[0123]

[0124] The distributed photovoltaic unit model is decentralized and connected to the 4th, 5th, 8th, 9th, 10th, 12th, 20th, 21st, 22nd, 24th, 25th, 26th, 28th, 30th, 32nd, and 33rd nodes of the power grid, as shown in Table 2.

[0125] Table 2: Distributed photovoltaic access situation

[0126]

[0127] Step 2.2: Determine the reactive power regulation direction of the converter in different scenarios. Calculate the voltage value of each node in the power grid in different scenarios And find the average voltage u vi The calculated average voltage u vi With rated voltage U N Compare and calculate the voltage deviation: Δu vi =u vi -U N ;

[0128] According to the calculation, the average voltage u in the two scenarios vi As follows: v1 =1.05198,u v2 =0.89893. Voltage deviation Δu in two scenarios vi As follows: Δu v1 =u v1 -U N =0.05198>0,Δu v2 =u v2 -U N =-0.10107<0.

[0129] Step 2.3: Determine the reactive power regulation of the converter under different scenarios;

[0130] First, the number of energy storage converters K = 14, distributed access to the grid nodes 2, 5, 9, 12, 15, 17, 21, 22, 24, 25, 28, 29, 32, 33, each with a reactive power regulation range {Q min,k ,Q max,k See Table 3. In scenario 1, α=5, and in scenario 2, β=5. The corresponding adjustment step sizes are shown in Table 3.

[0131] Table 3: Energy storage converter access and adjustment status

[0132]

[0133] Step 3: Quantify the loss reduction effect of energy storage converters participating in reactive power regulation under different typical operating scenarios, including:

[0134] Step 3.1: Based on the power grid built in step 2.1, use the line loss calculation function module to form an active power grid line loss calculation model. According to the formula The power flow calculation is performed in two scenarios to obtain the line loss reference value P when the energy storage converter is not connected to the reactive power output regulation. loss,i,before The calculation results are shown in Table 4.

[0135] Table 4: Initial line loss values ​​in various scenarios

[0136] Initial line loss values ​​in different scenarios Power / kW <![CDATA[P loss,1,before ]]> 138.8 <![CDATA[P loss,2,before ]]> 504.8

[0137] Step 3.2: In scenario 1, Δu v1 >0, with ΔQ k =40 (kvar) as the interval, and increase the reactive absorption of each energy storage converter in turn, and perform simulation calculations for α=5 times. The calculated line loss is recorded as In scenario 2, Δu v2 <0, with ΔQ k =100 (kvar) as an interval, and increase the reactive power output of each converter in turn, and perform simulation calculations for β = 5 times. The calculated line loss is recorded as The calculation results are shown in Tables 5 and 6.

[0138] Table 5: Reactive power output and line loss power in scenario 1

[0139]

[0140]

[0141] Table 6: Reactive power output and line loss power in scenario 2

[0142]

[0143] Step 3.3: Calculate the loss reduction rate to quantify the effect of the energy storage converter on reducing line losses:

[0144] η (.) loss,i >0: After adding the energy storage converter for reactive power regulation, the line loss is reduced compared to before regulation; η (.) loss,i <0: After adding the energy storage converter for reactive power regulation, the line loss value increases compared to before regulation. The calculation results are shown in Table 7.

[0145] Table 7: Loss reduction rate after reactive power regulation in scenario 1 and scenario 2

[0146]

[0147] Quantifying the voltage regulation effect of energy storage converters participating in reactive power regulation under different typical operating scenarios includes the following sub-steps:

[0148] Step 4.1: Under scenario 1, ΔQ k =40 (kvar) as the interval, and increase the reactive absorption of each energy storage converter in turn, and perform simulation calculations for α=5 times to obtain the voltage of each node, recorded as In scenario 2, ΔQ k =100 (kvar) as an interval, and increase the reactive power output of each converter in turn, and perform simulation calculations for β = 5 times to obtain the voltage of each node, recorded as Then calculate the voltage u of each node after the reactive output of the energy storage converter is regulated i,j (.) Voltage deviation:

[0149]

[0150] Step 4.2: Calculate the average voltage deviation To quantify the voltage regulation effect of the energy storage converter. The calculation results are shown in Table 8 and Table 9.

[0151] Table 8: Reactive power output and average voltage deviation in scenario 1

[0152]

[0153]

[0154] Table 9: Reactive power output and average voltage deviation in scenario 2

[0155]

[0156] Quantify the power factor improvement effect of energy storage converters participating in reactive power regulation under different typical operating scenarios, including the following sub-steps:

[0157] Step 5.1: Based on the power grid built in step 2.1, perform power flow calculation and record the power factor reference value cosθ of monitoring point A (between the headend nodes 1 and 2) before the energy storage converter is connected i,before The calculation results are shown in Table 10.

[0158] Table 10: Initial power factor of monitoring point A in each scenario

[0159] Initial power factor in different scenarios Numeric <![CDATA[cosθ 1,before ]]> 0.9826 <![CDATA[cosθ 2,before ]]> 0.9565

[0160] In scenario 1, Δu v1 >0, with ΔQ k=40 (kvar) as the interval, the reactive power absorption of each energy storage converter is increased in sequence, and the simulation calculation is performed for α=5 times. The calculated power factor is recorded as The calculation results are shown in Table 11. Under scenario 2, Δu v2 <0, with ΔQ k =100 (kvar) as the interval, increase the reactive power output of each converter in turn, perform β = 5 simulation calculations, and record the calculated power factor as The calculation results are shown in Tables 11 and 12.

[0161] Table 11: Reactive power output and power factor in scenario 1

[0162]

[0163] Table 12: Reactive power output and power factor in scenario 2

[0164]

[0165] Step 5.2: Calculate the relative power factor improvement Δcosθ i (.) To quantify the effect of energy storage converter on power factor improvement. The calculation results are shown in Table 13.

[0166] Table 13: Relative power factor improvement after reactive power regulation in scenario 1 and scenario 2

[0167] <![CDATA[Δcosθ1 1 ]]> <![CDATA[Δcosθ1 2 ]]> <![CDATA[Δcosθ1 3 ]]> <![CDATA[Δcosθ1 4 ]]> <![CDATA[Δcosθ1 5 ]]> 0.0151 -0.0321 -0.1224 -0.2277 -0.3295 <![CDATA[Δcosθ2 1 ]]> <![CDATA[Δcosθ2 2 ]]> <![CDATA[Δcosθ2 3 ]]> <![CDATA[Δcosθ2 4 ]]> <![CDATA[Δcosθ2 5 ]]> 0.0400 0.0353 -0.0063 -0.0651 -0.1249

[0168] Step 6: Evaluate the comprehensive effect of the energy storage converter participating in reactive power regulation, including:

[0169] Step 6.1: Use the maximum and minimum standardization method to normalize the indicators of the loss reduction effect, voltage regulation effect and power factor improvement effect of the quantified energy storage converter participating in reactive power regulation to the same scale. The values ​​of the indicators after normalization are shown in Table 14, Table 15 and Table 16;

[0170] Table 14: Loss reduction rate after normalization

[0171] <![CDATA[η 1 ′ loss,1 ]]> <![CDATA[η 2 ′ loss,1 ]]> <![CDATA[η 3 ′ loss,1 ]]> <![CDATA[η 4 ′ loss,1 ]]> <![CDATA[η 5 ′ loss,1 ]]> 1.0000 0.9417 0.7600 0.4488 0.0000 <![CDATA[η 1 ′ loss,2 ]]> <![CDATA[η 2 ′ loss,2 ]]> <![CDATA[η 3 ′ loss,2 ]]> <![CDATA[η 4 ′ loss,2 ]]> <![CDATA[η 5 ′ loss,2 ]]> 1.0000 0.9463 0.7513 0.4319 0.0000

[0172] Table 15: Average voltage deviation after normalization

[0173]

[0174] Table 16: Relative power factor improvement after normalization

[0175] <![CDATA[Δcosθ1 1′ ]]> <![CDATA[Δcosθ1 2′ ]]> <![CDATA[Δcosθ1 3′ ]]> <![CDATA[Δcosθ1 4′ ]]> <![CDATA[Δcosθ1 5′ ]]> 1.0000 0.8630 0.6010 0.2954 0.0000 <![CDATA[Δcosθ2 1′ ]]> <![CDATA[Δcosθ2 2′ ]]> <![CDATA[Δcosθ2 3′ ]]> <![CDATA[Δcosθ2 4′ ]]> <![CDATA[Δcosθ2 5′ ]]> 1.0000 0.9715 0.7192 0.3626 0.0000

[0176] Step 6.2: Assign weights. In this example, Then the weighted sum is used to obtain the comprehensive score S of each reactive regulation quantity in different scenarios. i (.) .

[0177] Scenario 1:

[0178]

[0179] Scenario 2:

[0180]

[0181] The value of the comprehensive score is an evaluation of the comprehensive effect of the energy storage converter participating in the reactive power regulation of the power grid. The reactive power output scheme with a high score has a better optimization effect on the operation of the power grid and can better improve the overall performance of the power grid. On the contrary, a low score indicates that the improvement effect of reactive power output in these aspects is weak, and the operation efficiency of the power grid is relatively poor. The higher the comprehensive score, the better the reactive power regulation effect of the energy storage converter and the better the overall performance of the power grid. In the above specific example, under typical scenario 1, ΔQ k =-80 (kvar), the comprehensive score is the highest value, that is, S1 2 =0.6836, the reactive power regulation effect is the best; in typical scenario 2, ΔQ k =200 (kvar), the comprehensive score is the highest value, that is, S2 2 =0.7365, the reactive power regulation effect is the best.

[0182] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A comprehensive evaluation method for the effect of energy storage converters participating in reactive power regulation of power grids, characterized in that: It includes the following sub-steps: Determine the typical operating scenarios of energy storage converters participating in reactive power regulation; Determine the reactive power regulation of the energy storage converter under different typical operating scenarios; Based on the reactive power regulation of energy storage converters in different typical operating scenarios, the loss reduction effect, voltage regulation effect and power factor improvement effect of energy storage converters participating in reactive power regulation in different typical operating scenarios are quantified; Based on the quantified loss reduction effect, voltage regulation effect and power factor improvement effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios, the comprehensive effect of the energy storage converter participating in reactive power regulation is evaluated.

2. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 1 is characterized in that: Determining the typical operating scenario of the energy storage converter participating in reactive power regulation includes the following sub-steps: Step 1.1: Collect typical daily power generation data of renewable energy in the region to be evaluated, with a step length of T minutes, to form a power generation data set {P W1 ,P W2 ,…,P Wt ,…,P W(1440 / T) }, where P Wt is the t-th power generation; at the same time, the typical daily data of load power consumption in the area to be evaluated is collected, with a step length of T minutes, to form a load power consumption data set {P L1 ,P L2 ,…,P Lt ,,P L(1440 / T) }, where P Lt is the power consumption of the tth load; Step 1.2: Calculate the difference between the power generated by renewable energy and the power consumed by the load, and take max{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 1, when the photovoltaic power generation is large and the load is small; take min{P Wt -P Lt The time t corresponding to} is taken as the typical operation scenario 2, when the photovoltaic power generation is not performed and the load is large.

3. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 2 is characterized in that: Determining the reactive power regulation of the energy storage converter under different typical operating scenarios includes the following sub-steps: Step 2.1: Based on the actual power grid data of the area to be evaluated, build a power grid containing new energy in the power system simulation analysis software, with the number of nodes N, and calculate the voltage value u of each node under each typical operation scenario i ij , where i is the typical operation scenario number and j is the node number; and calculate the voltage average value u in the i-th typical operation scenario vi ,in Step 2.2: The calculated average voltage value u vi With rated voltage U N Compare and calculate the voltage deviation: Δu vi =u vi -U N ; When Δu vi >0, the voltage of the i-th typical operation scenario is too high, and the energy storage converter should gradually absorb reactive power; when Δu vi When <0, the grid voltage of the i-th typical operation scenario is low, and the energy storage converter should gradually generate reactive power; Step 2.3: Count the number of energy storage converters K and the reactive power regulation range of the kth converter {Q min,k ,Q max,k }, when Δuvi>0, select the adjustment step From 0 to Q min,k Increase the reactive absorption in sequence; when Δu vi <0, select adjustment step From 0 to Q max,k Increase the reactive power output in sequence; α and β are the grading coefficients, which are positive integers.

4. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 3 is characterized in that: Quantifying the loss reduction effect of energy storage converters participating in reactive power regulation under different typical operating scenarios includes the following sub-steps: Step 3.1: Based on the power grid built in step 2.1, perform power flow calculations under different typical operating scenarios to obtain the line loss baseline value when the energy storage converter is not connected to reactive power regulation, denoted as P loss,i,before ; Step 3.2: According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k As interval, the reactive absorption of each energy storage converter is increased in sequence, and simulation calculations are performed for α times. The calculated line loss is recorded as When Δu vi When ΔQ k As interval, the reactive power output of each energy storage converter is increased in sequence, and β simulation calculations are performed. The calculated line loss is recorded as Step 3.3: In any simulation calculation of step 3.2, the line loss reduction effect of the energy storage converter on the line loss is quantified by the line loss baseline value and the line loss reduction rate. The specific formula is: Among them, m=1,...,α, n=1,...,β; represents the line loss value of the mth simulation in the αth simulation of the i-th typical operation scenario, η m loss,i represents the loss reduction rate of the mth simulation; represents the line loss value of the nth simulation in the βth simulation of the i-th typical operation scenario, η n loss,i Represents the loss reduction rate of the nth simulation.

5. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 4 is characterized in that: Quantifying the voltage regulation effect of energy storage converters participating in reactive power regulation under different typical operating scenarios includes the following sub-steps: Step 4.1: Based on the power grid built in step 2.1, according to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive absorption of each energy storage converter is increased in turn and the power flow simulation calculation is performed for α times. The voltage of each node is recorded as When Δu vi When ΔQ k The reactive power output of each energy storage converter is increased at intervals, and the β-time power flow simulation calculation is performed. The voltage of each node is recorded as The voltage deviation of each node voltage after the reactive output adjustment of the energy storage converter is obtained. The specific formula is: Among them, u i,j α,m represents the voltage of each node in the mth simulation, Δu i,j m Indicates u i,j α,m Voltage deviation, u i,j β,n represents the voltage of each node in the nth simulation, Δu i,j n Indicates u i,j β,n Voltage deviation; Step 4.2: For each reactive power regulation, the voltage regulation effect of the energy storage converter is quantified by calculating the average voltage deviation. The specific formula is: in, represents the average voltage deviation of the mth simulation in α, It represents the average voltage deviation of the nth time in the β simulation.

6. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 5 is characterized in that: Quantify the power factor improvement effect of energy storage converters participating in reactive power regulation under different typical operating scenarios, including the following sub-steps: Step 5.1: Based on the power grid built in step 2.1, perform power flow calculation and record the power factor reference value cosθ of monitoring point A before the energy storage converter is connected i,before ; The grid is connected to the energy storage converter. According to the reactive power regulation determined in step 2.3, when Δu vi >0, with ΔQ k The reactive power absorption of each converter is increased at intervals, and simulation calculations are performed for α times. The power factors are recorded as When Δu vi When ΔQ k The reactive power output of each converter is increased at intervals, and β simulation calculations are performed. The power factors are recorded as Step 5.2: For each reactive power regulation, the effect of the energy storage converter on the power factor improvement is quantified by the power factor baseline value and the relative power factor improvement calculated by the power factor. The specific formula is: Among them, cosθ i,after α,m represents the mth power factor in the α simulation, Δcosθ i m represents cosθ i,after α,m The amount of improvement; cosθ i,after β,n represents the nth power factor in the β simulation, Δcosθ i n represents cosθ i,after β,n The amount of improvement.

7. The comprehensive evaluation method for the effect of energy storage converter participating in reactive power regulation of power grid according to claim 6 is characterized in that: Evaluate the comprehensive effect of energy storage converter participating in reactive power regulation, including the following sub-steps: Step 6.1: Use the maximum and minimum standardization method to quantify the loss reduction effect and regulation effect of the energy storage converter participating in reactive power regulation. The indicators of pressure effect and power factor improvement effect are normalized to the same scale, and the standardized value range is 0 to 1; The standardized processing formula for each reactive regulation quantity in the i-th typical operation scenario is as follows: Standardization of loss reduction effects: The normalized result of the voltage regulation effect is negated: Standardization of power factor improvement effect: Step 6.2: Assign weights, and then obtain the comprehensive score for each reactive power regulation quantity by weighted summation. The calculation formula for the comprehensive score is: Among them, z η 、z Δu 、z Δcosθ They are the weights of loss reduction effect, voltage regulation effect and power factor improvement effect, which are set according to actual needs; S i m is the comprehensive score of the mth reactive regulation quantity under the ith typical operation scenario; S i n It is the comprehensive score of the nth reactive power regulation quantity in the ith typical operation scenario.

8. A device for comprehensively evaluating the effect of energy storage converters participating in reactive power regulation of power grids, characterized in that: The device includes: A scenario determination module, used to determine a typical operation scenario in which the energy storage converter participates in reactive power regulation; A quantification module is used to quantify the effect of the energy storage converter participating in reactive power regulation under different typical operation scenarios based on the reactive power regulation amount of the energy storage converter under different typical operation scenarios; The evaluation module is used to evaluate the comprehensive effect of the energy storage converter participating in reactive power regulation based on the quantified effect of the energy storage converter participating in reactive power regulation under different typical operating scenarios.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement a comprehensive evaluation method for the effect of an energy storage converter participating in reactive power regulation of a power grid as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for comprehensively evaluating the effect of the energy storage converter participating in the reactive power regulation of the power grid as described in any one of claims 1 to 7 is implemented.

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