A design method for active over-provisioning of PCS for power storage

Abstract

The present invention provides a design method for active over-provisioning of a PCS for power energy storage, the method comprising the following steps: step S1, reactive matching calculation, defining a first input package, and outputting various powers of an energy storage station; step S2, judging whether a PCS active over-provisioning ratio value after reactive matching calculation as an output result of step S1 satisfies a minimum setting value of the PCS active over-provisioning ratio; step S3, system matching calculation, defining a second input package, and outputting a parameter of a battery in an energy storage power station; step S4, judging whether an actual calculated value of the battery active over-provisioning ratio as an output result of step S3 satisfies a minimum setting value of the battery active over-provisioning ratio and a maximum setting value of the battery active over-provisioning ratio; step S5, optimizing matching calculation, and defining a third input package; the present invention can perform reactive matching calculation, system matching calculation and optimized matching calculation respectively by setting input parameters, and obtain a value suitable for as many PCS devices as possible.

Description

Technical Field

[0001] The present invention relates to the technical field of power energy storage equipment, and in particular to an active over-allocation design method for power energy storage PCS. Background Art

[0002] The construction of a new power system with new energy as the main body will bring about major changes in the power supply characteristics and safe operation characteristics of the new power system, and energy storage will play a vital role. At present, electrochemical energy storage represented by LFP has been commercially applied, and energy storage power stations are gradually developing towards the GW level or even the TW level. At present, large-capacity centralized energy storage power stations mostly adopt AC topology solutions, and the reactive power compensation device of the energy storage power station is configured according to the principle of local balance of reactive power compensation of the power system, facilitating voltage adjustment and meeting positioning requirements.

[0003] The power system generally requires that the leading or lagging power factor of the energy storage power station at the grid connection point should not be less than 0.95 when the power system provides reactive power to the energy storage power station in the grid-connected operation mode and does not participate in the reactive power regulation of the system. The energy storage converter can be dynamically adjustable between 0.95 lagging phase and 0.95 leading phase when operating at full power, and can be used as a reactive power source for the energy storage power station. In the design of energy storage power stations, there are generally the following routes:

[0004] Only SVG is considered as a reactive power regulation device, and the linkage PCS device is not considered. In this respect, SVG has a large capacity design, high investment cost, and simple control and management;

[0005] PCS is given priority as a reactive power regulation device. When its reactive power regulation capability is limited, dynamic reactive power compensation device SVG is considered. The required target value is calculated based on the collected analog quantity and the controlled reactive power for compensation. The control strategy is relatively complex and the operation is not ideal in actual projects. This is reflected in the fact that the proportion and priority order of reactive power distribution between PCS and SVG cannot be unified, and even system mismatch occurs, or neither responds to instructions.

[0006] In addition to ensuring the PCS active power, a part of the PCS capacity is actively over-allocated to take on the role of reactive power regulation, and no separate SVG device is configured.

[0007] Route 3 has been adopted by some energy storage stations, but as of now, there is no unified calculation method and standard for active over-allocation. It is also easy to ignore the matching requirements with the equipment itself and system design during existing engineering design, resulting in poor engineering integration standardization capabilities. Summary of the invention

[0008] In view of this, an object of the present invention is to provide a method that can perform reactive matching calculation, system matching calculation and optimized matching calculation respectively by setting input parameters, so as to obtain a method that is suitable for as many PCS devices as possible.

[0009] The present invention is implemented by the following method: a method for active over-allocation design of power energy storage PCS, the method comprising the following steps:

[0010] Step S1, reactive matching calculation, defining the first input package, and the output result is various powers of the energy storage station;

[0011] Step S2, judging whether the PCS active over-provision ratio value after reactive matching calculation of the output result of step S1 satisfies or is greater than or equal to the minimum setting value of the PCS active over-provision ratio, if yes, proceeding to the next step, if no, verifying and resetting the first input report parameter;

[0012] Step S3: system matching calculation, defining the second input package, and outputting the parameters of the energy storage power station battery;

[0013] Step S4, judging whether the actual calculated value of the battery active over-provision ratio as the output result of step S3 satisfies the requirement that the actual calculated value of the battery active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio, and whether the actual calculated value of the PCS active over-provision ratio satisfies the requirement that the actual calculated value of the PCS active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio. If yes, then transfer to the optimization matching calculation; if no, then verify and reset the parameters of the second input package.

[0014] Step S5, optimize the matching calculation, define the third input package, and output the optimal conditions that meet various energy storage power stations. Determine whether the output result of the minimum price of the energy storage system equipment is the optimal solution. If yes, end the process. If not, go to step S1 to verify and reset the parameters of the first input package.

[0015] Furthermore, the step S1 is further specified as follows: reactive matching calculation, defining a first input package, wherein the elements of the first input package include parameters such as the rated active power of the energy storage power station, the leading or lagging power factor at the grid connection point, the reactive power source, the reactive power consumption, the reactive balance shortfall, and the minimum setting value of the PCS active over-allocation ratio; the output result is the rated apparent power of the energy storage power station, the reactive exchange power of the access point, the reactive balance shortfall, the PCS active over-allocation ratio value after reactive matching calculation, and the reactive matching calculation of the active power of the energy storage power station.

[0016] Furthermore, the step S3 is further specified as follows: system matching calculation, defining a second input package, wherein the elements of the second input package include the DC system voltage of the energy storage power station, the charge and discharge ratio of the energy storage system, the rated power of a single PCS, the number of PCSs corresponding to a single transformer, the capacity of the connected transformer, the installed capacity of the connected battery compartment, the active power of the energy storage power station after matching with the battery, the minimum setting value of the battery active over-provisioning ratio, the maximum setting value of the battery active over-provisioning ratio, the minimum setting value of the PCS active over-provisioning ratio, and the maximum setting value of the PCS active over-provisioning ratio; the output result is the minimum installed capacity value of the battery active over-provisioning ratio, the active power of the energy storage power station after matching with the battery, the active power of the energy storage power station after matching with the reactive power and the battery, the calculated number of PCS installations, the calculated number of PCS and converter integrated cabin installations, the actual number of PCS and converter integrated cabin installations, the actual installed capacity value of the battery after matching with the PCS, the active power of the energy storage power station after matching with the reactive power, the battery, and the equipment, the actual calculated value of the battery active over-provisioning ratio, and the actual calculated value of the PCS active over-provisioning ratio.

[0017] Furthermore, the step S5 is further specified as follows: optimizing the matching calculation, defining a third input package, wherein the elements of the third input package include the actual calculated value of the battery active over-matching ratio after satisfying the system matching judgment, the actual calculated value of the PCS active over-matching ratio after satisfying the system matching judgment, the battery system unit price, and the PCS system unit price; the output result is the actual installed capacity value of the battery after satisfying the system matching judgment, the active power of the energy storage power station after satisfying the system matching judgment, and the price of the energy storage system equipment.

[0018] The beneficial effects of the present invention are as follows: the present invention sets input parameters, performs reactive matching calculation, system matching calculation and optimized matching calculation respectively, and obtains the optimal active over-matching design scheme suitable for as many PCS devices as possible, so as to form a product with modularization capability; by actively over-matching the energy storage PCS, the setting of SVG devices is avoided, and most of the reactive power sources come from the PCS; the AVC module in the EMS system only needs to decompose the reactive instructions of the PCS device, and the PCS responds to the instructions through the PQ control mode to ensure that within 30ms, the reactive power regulation requirements of the system and the energy storage station itself can be met, while avoiding system mismatch, which brings favorable conditions for ensuring the safe and reliable operation of the energy storage power station; after the energy storage PCS is over-matched, the additional land occupation index is not increased, and the operation and maintenance equipment is reduced, thereby reducing the operation and maintenance workload; the energy storage PCS equipment is generally installed indoors or in the cabin, and the operating conditions are good. Compared with the outdoor SVG device, the reliability of the equipment and the energy storage power station is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the method flow of the present invention.

[0020] Figure 2It is a schematic diagram of the process of the present invention.

[0021] Figure 3 This is a schematic diagram showing an example of reactive power matching calculation.

[0022] Figure 4 This is a diagram showing an example calculation of system matching.

[0023] Figure 5 Schematic diagram of an example calculation for optimizing matching calculation. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] See also Figure 1 and Figure 2 As shown, the present invention provides a method for active over-allocation design of power energy storage PCS, the method comprising the following steps:

[0026] Step S1, reactive matching calculation, defining the first input package, and the output result is various powers of the energy storage station;

[0027] Step S2, judging whether the PCS active over-provision ratio value after reactive matching calculation of the output result of step S1 satisfies or is greater than or equal to the minimum setting value of the PCS active over-provision ratio, if yes, proceeding to the next step, if no, verifying and resetting the first input report parameter;

[0028] Step S3: system matching calculation, defining the second input package, and outputting the parameters of the energy storage power station battery;

[0029] Step S4, judging whether the actual calculated value of the battery active over-provision ratio as the output result of step S3 satisfies the requirement that the actual calculated value of the battery active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio, and whether the actual calculated value of the PCS active over-provision ratio satisfies the requirement that the actual calculated value of the PCS active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio. If yes, then transfer to the optimization matching calculation; if no, then verify and reset the parameters of the second input package.

[0030] Step S5, optimize the matching calculation, define the third input package, and output the optimal conditions that meet various energy storage power stations. Determine whether the output result of the minimum price of the energy storage system equipment is the optimal solution. If yes, end the process. If not, go to step S1 to verify and reset the parameters of the first input package.

[0031] The present invention will be further described below by a specific embodiment:

[0032] The following PCS is an energy storage converter.

[0033] See also Figure 3As shown, in one embodiment of the present invention, reactive matching calculation defines a first input package, the elements of which include the rated active power of the energy storage power station, the leading or lagging power factor at the grid connection point, the reactive power source, the reactive power consumption, the reactive balance shortfall, the minimum setting value of the PCS active over-provisioning ratio of the energy storage converter, and other parameters. The output result is the rated apparent power of the energy storage power station, the reactive exchange power of the access point, the reactive balance shortfall, the PCS active over-provisioning ratio value after reactive matching calculation, and the active power of the energy storage power station calculated by reactive matching. Determine whether the PCS active over-provisioning ratio value after the reactive matching calculation of the output result satisfies or is greater than or equal to the minimum setting value of the PCS active over-provisioning ratio. If so, transfer to the system matching calculation. If not, check and reset the parameters of the first input package, and repeat the above operation.

[0034] Step S2 is illustrated by way of example: In the first input packet, the rated active power P of a certain energy storage power station is 0 The leading or lagging power factor Cosα at the grid connection point is 0.95, and the reactive power source Q 1 is 5.23 MVar, reactive power loss Q 2 is 69.17 MVar, setting the minimum value of PCS active over-provisioning ratio η p0 is 7%; the output result is the rated apparent power S of the energy storage station 0 =P 0 / Cosα is 315.79 MVar, and the access point reactive exchange power Q 0 =S0*Sin(Acos(Cosα)) is 98.61Mvar, reactive power balance shortfall Q 3 =Q0+Q2-Q1 is 162.55Mvar, and the PCS active over-provision ratio value η after reactive matching calculation p1 =SQRT(P ^ 2+Q3 ^ (P 0 2 +Q 3 2 ) / S 0 is 8.05%, reactive matching calculation of energy storage power station active power P 1 =(1+η p1 )*P 0 is 324.14MW. Through step S2, the output result η can be determined p1 8.05% is greater than or equal to the minimum setting value η of the PCS active over-provisioning ratio p0 7%, proceed to step S3;

[0035] See also Figure 4As shown, in one embodiment of the present invention, the system matching calculation defines a second input package, and the elements include the DC system voltage of the energy storage power station, the charge and discharge ratio of the energy storage system, the rated power of a single PCS, the number of PCSs corresponding to a single transformer, the capacity of the connected transformer, the installed capacity of the connected battery compartment, the active power of the energy storage power station after matching with the battery, the minimum setting value of the battery active over-provisioning ratio, the maximum setting value of the battery active over-provisioning ratio, the minimum setting value of the PCS active over-provisioning ratio, and the maximum setting value of the PCS active over-provisioning ratio. The output result is the minimum installed capacity value of the battery active over-provisioning ratio, the active power of the energy storage power station after matching with the battery, the active power of the energy storage power station after matching with the reactive power and the battery, the calculated value of the number of PCS installations, the calculated number of PCS and converter integrated cabin installations, the actual number of PCS and converter integrated cabin installations, the actual installed capacity value of the battery after matching with the PCS, the active power of the energy storage power station after matching with the reactive power, the battery, and the equipment, the actual calculated value of the battery active over-provisioning ratio, and the actual calculated value of the PCS active over-provisioning ratio. Determine whether the actual calculated value of the battery active over-provision ratio satisfies the output result that it is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio, and whether the actual calculated value of the PCS active over-provision ratio satisfies the value that it is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio. If both are satisfied, switch to the optimization matching calculation. If not satisfied, check and reset the parameters of the second input package and repeat the above operation.

[0036] Step S3 is illustrated by way of example: the DC system voltage U of the energy storage power station xt , energy storage system charge and discharge rate C, single PCS rated power P i 、The number of PCSs corresponding to a single transformer is M 1 , the connected transformer capacity S tbi 、The installed capacity of the connected battery compartment S bati , after matching with the battery, the active power of the energy storage station P 2 , the minimum setting value of the battery active over-provisioning ratio η b0 , Maximum setting value of battery active over-provision ratio η b0' 、PCS active over-provisioning ratio minimum setting value η p0 、PCS active over-provisioning ratio maximum setting value η p0' , a total of 6 schemes are listed in the example. Taking the 5th scheme as an example, the second input package is set to 1500V, 0.5, 1.5MW, 2, 3.15MVA, 6.71MVA, 15%, 20%, 7%, 20%; the output result is the minimum installed capacity value S of the battery active over-provisioning ratio bat1 =P 0 / C*(1+η b0 ) is 642MWh, the battery active over-provisioning ratio is the lowest. The number of battery compartment installation calculation sets M2 =ROUNDUP(S bat1 / S bati ,0) is 96 sets, the battery active over-provision ratio is the lowest, the number of battery compartment installation selection sets M 3 =IF(INT(M 2 / 2)=M 2 / 2,M 2 ,M 2 +1) is 96 sets, and after matching with the battery, the active power of the energy storage station is P 2 =M 3 *P i *M 1 *C*(ROUND(S bati / S tbi ,0))=288MW, after matching with reactive power and battery, the active power of energy storage station P 3 =MAX(P 1 , P 2 ) is 324.14MW, and the number of PCS installation calculations after matching with reactive power and batteries is M 4 =ROUNDUP(P 3 / P i ,0) is 217 sets, and the number of PCS and booster integrated cabin installation calculation sets after matching with reactive power and battery is M 5 =ROUNDUP(M 4 / M 1 ,0) is 109 sets, and after matching with reactive power and battery, PCS and booster integrated cabin installation selection number M 6 =IF(INT(M 5 / 2)=M 5 / 2,M 5 ,M 5 +1) is 110 sets, and the actual installed capacity of the battery after matching with PCS is S bat2 =M 6 *ROUND(S bati / S tbi / C,0)*S bati It is 738.02MWh. After matching with reactive power, batteries and equipment, the active power of the energy storage station is P 4 =M 6 *M 1* P i The actual calculated value of the battery active over-provision ratio is η, which is 330MW. b2 =(S bat2 / P 0 / C-1)*100% is 23.00%, the actual calculated value of PCS active over-allocation ratio η p2 =(P 4 / P 0-1)*100% is 10.00%. Through step S3, the output result η can be determined. b2 23.00% satisfies the minimum setting value η of the battery active over-provisioning ratio b0 And less than or equal to the maximum setting value η of the battery active over-provision ratio b0' , η p2 Whether it meets or exceeds the minimum setting value η of the battery active over-provisioning ratio p0 15%, but not less than or equal to the maximum setting value η of the battery active over-provisioning ratio p0 20%, the system matching battery active over-matching calculation judgment result is mismatch, the judgment output result η p2 10.00% satisfies the minimum setting value η of the PCS active over-provisioning ratio p0 7% and less than or equal to the maximum setting value η of the PCS active over-provisioning ratio p0' 20%, the system matching PCS active over-allocation calculation result is a match. Since one or two of the system matching battery and PCS active over-allocation calculation results are mismatched, the total system matching calculation result is a mismatch. The second input package parameters are checked and reset. Repeat the above operation until the total system matching calculation result is a match, and then enter the optimization matching calculation;

[0037] See also Figure 5 As shown, in one embodiment of the present invention, the matching calculation is optimized, and the third input package is defined. The elements include the actual calculated value of the battery active over-allocation ratio after satisfying the system matching judgment, the actual calculated value of the PCS active over-allocation ratio after satisfying the system matching judgment, the battery system unit price, and the PCS system unit price. The output result is the actual installed capacity value of the battery after satisfying the system matching judgment, the active power of the energy storage power station after satisfying the system matching judgment, and the price of the energy storage system equipment. The minimum value of the energy storage system equipment price of the output result is determined to be the optimal solution. If it is not satisfied, it is transferred to the reactive matching calculation, and the parameters of the first input package are verified and reset, and the above operation is repeated;

[0038] If the output result is unique, the process ends.

[0039] Step S4 is illustrated by example: Battery system unit price A 1 、PCS system unit price A 2 , a total of 6 schemes are listed in the example. In the third input package, the settings are 1.5, 0.22 and 1.6, 0.2 for 1000V air cooling and 1500V liquid cooling respectively. The output results meet the actual calculated value η of the battery active over-matching ratio after system matching judgment. b3 =IF(Step 2 System Matching Battery Active Over-matching Calculation Judgment Result = "Mismatch", "Not Satisfied", η b2 ), corresponding to 6 example solutions n p3They are: not satisfied, 16.01%, 7.35%, 7.35%, not satisfied, not satisfied, and the actual calculated value of the PCS active over-provisioning ratio after satisfying the system matching judgment is η p3 =IF(Step 2 System Matching PCS Active Over-Provisioning Calculation Judgment Result = "Mismatch", "Not Satisfied", η p2 ), corresponding to 6 example solutions n p3 They are: 9.33%, 14.24%, 15.20%, 20.00%, 10.00%, 8.10%, and the actual installed capacity value S of the battery after the system matching judgment is met bat2 =IF(η b3 = "Not satisfied", "Not satisfied", P 0 / C*(1+η b2 ), 706.28, 644.09, 644.09MWh, corresponding to 6 example schemes S bat2 They are: not satisfied, 696.04, 644.09, 644.09, not satisfied, not satisfied, and the active power P of the energy storage power station after the system matching judgment is satisfied 4 =IF(η p3 = "Not satisfied", "Not satisfied", P 0 *(1+η p2 )), corresponding to 6 example solutions P 4 They are: 328.00, 347.72, 345.60, 360.00, 330.00MW, the main equipment price of energy storage system B = IF (OR (S bat2 = "Not satisfied", P 4 = "Not satisfied"),"Not satisfied",S bat2 *A 1 / 100+P 4 *A 1 / 100), the corresponding 6 example solutions B are: not satisfied, 1.119 billion, 1.100 billion, 1.103 billion, not satisfied, not satisfied. The minimum value in the output result B is determined to be the optimal solution. If there are two minimum values, the parameters of the first input package are verified and reset, and the above operation is repeated. If satisfied, the output result is only unique at this time, and the process ends.

[0040] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A design method for active over-allocation of PCS for power storage, It is characterized in that The method comprises the following steps: Step S1, reactive matching calculation, defining the first input package, and the output result is various powers of the energy storage station; Step S2, judging whether the PCS active over-provision ratio value after reactive matching calculation of the output result of step S1 satisfies or is greater than or equal to the minimum setting value of the PCS active over-provision ratio, if yes, proceeding to the next step, if no, verifying and resetting the first input report parameter; Step S3: system matching calculation, defining the second input package, and outputting the parameters of the energy storage power station battery; Step S4, judging whether the actual calculated value of the battery active over-provision ratio as the output result of step S3 satisfies the requirement that the actual calculated value of the battery active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio, and whether the actual calculated value of the PCS active over-provision ratio satisfies the requirement that the actual calculated value of the PCS active over-provision ratio is greater than or equal to the minimum set value of the battery active over-provision ratio and less than or equal to the maximum set value of the battery active over-provision ratio. If yes, then transfer to the optimization matching calculation; if no, then verify and reset the parameters of the second input package. Step S5, optimize the matching calculation, define the third input package, and output the optimal conditions that meet various energy storage power stations. Determine whether the output result of the minimum price of the energy storage system equipment is the optimal solution. If yes, end the process. If not, go to step S1 to verify and reset the parameters of the first input package.

2. According to claim 1, a method for active over-allocation design of power energy storage PCS, Features: The step S1 is further specified as follows: reactive matching calculation, defining a first input package, the elements of which include the rated active power of the energy storage power station, the leading or lagging power factor at the grid connection point, the reactive power source, the reactive power consumption, the reactive balance shortfall, and the minimum setting value of the PCS active over-allocation ratio; the output result is the rated apparent power of the energy storage power station, the reactive exchange power of the access point, the reactive balance shortfall, the PCS active over-allocation ratio value after reactive matching calculation, and the reactive matching calculation of the active power of the energy storage power station.

3. According to claim 1, a method for active over-allocation design of power energy storage PCS, Features: The step S3 is further specifically as follows: system matching calculation, defining a second input package, the elements of which include the DC system voltage of the energy storage power station, the charge and discharge ratio of the energy storage system, the rated power of a single PCS, the number of PCSs corresponding to a single transformer, the capacity of the connected transformer, the installed capacity of the connected battery compartment, the active power of the energy storage power station after matching with the battery, the minimum setting value of the battery active over-provisioning ratio, the maximum setting value of the battery active over-provisioning ratio, the minimum setting value of the PCS active over-provisioning ratio, and the maximum setting value of the PCS active over-provisioning ratio; the output result is the minimum installed capacity value of the battery active over-provisioning ratio, the active power of the energy storage power station after matching with the battery, the active power of the energy storage power station after matching with the reactive power and the battery, the calculated number of PCS installations, the calculated number of PCS and converter integrated cabin installations, the actual number of PCS and converter integrated cabin installations, the actual installed capacity value of the battery after matching with the PCS, the active power of the energy storage power station after matching with the reactive power, the battery and the equipment, the actual calculated value of the battery active over-provisioning ratio, and the actual calculated value of the PCS active over-provisioning ratio.

4. According to claim 1, a method for active over-allocation design of power energy storage PCS, Features: The step S5 is further specified as follows: optimizing the matching calculation, defining a third input package, wherein the elements of the third input package include the actual calculated value of the battery active over-matching ratio after satisfying the system matching judgment, the actual calculated value of the PCS active over-matching ratio after satisfying the system matching judgment, the battery system unit price, and the PCS system unit price; the output result is the actual installed capacity value of the battery after satisfying the system matching judgment, the active power of the energy storage power station after satisfying the system matching judgment, and the price of the energy storage system equipment.

Images