Current limiting control method of network construction type equipment, electronic equipment and storage medium

Abstract

The invention provides a current-limiting control method of network-forming equipment, electronic equipment and a storage medium, and the method comprises the steps: increasing the compensation amount to the output side of a voltage loop when the network-forming equipment is in a current-limiting mode, so as to enable the lower bound of a current-limiting exit interval to be equal to an initial power angle and the upper bound of the current-limiting exit interval to be smaller than or equal to a current-limiting power angle; the compensation amount is used for correcting the current reference value calculated by the voltage loop. According to the invention, the problem of repeated switching of latching and mode switching in current-limiting control of network-forming equipment can be effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power electronics, and particularly relates to a current limiting control method of grid-forming equipment, an electronic device and a storage medium. BACKGROUND

[0002] When the power system is subjected to short-circuit fault, the power electronic equipment with current limiting measures may overcurrent. Since the overcurrent capacity of the power electronic equipment is far lower than that of the synchronous machine, overcurrent may cause damage to the equipment, so it is necessary to add current limiting measures to the control of the power electronic equipment. The current limiting judgment condition of the existing current limiting control strategy cannot ensure that the grid-forming equipment reasonably exits the current limiting, and may face the problems of latching and repeated switching of mode switching. The latching problem refers to that the grid-forming equipment cannot exit the current limiting mode after the fault ends; the repeated switching of mode switching problem refers to that the operating mode of the grid-forming equipment is repeatedly switched between current limiting and non-current limiting after the fault ends. Both of the two problems threaten the normal operation of the grid-forming equipment. SUMMARY

[0003] The present application provides a current limiting control method of grid-forming equipment, an electronic device and a storage medium, which can effectively solve the problems of latching and repeated switching of mode switching in the current limiting control of the grid-forming equipment.

[0004] The present application provides a current limiting control method of grid-forming equipment, comprising: when the grid-forming equipment is in a current limiting mode, adding a compensation amount to the output side of a voltage loop to make the lower limit of a current limiting exit interval equal to an initial power angle, and the upper limit of the current limiting exit interval less than or equal to a current limiting power angle; the compensation amount is used to correct a current reference value calculated by the voltage loop.

[0005] The current limiting control method of grid-forming equipment provided by the present application further comprises: when the grid-forming equipment is in a normal mode, there is no compensation amount on the output side of the voltage loop.

[0006] The current limiting control method of grid-forming equipment provided by the present application, when the grid-forming equipment is in a normal mode, comprises: when a normal operating condition is met, the grid-forming equipment is in the normal mode, the input of a voltage loop integrator is the deviation of a grid-connected point voltage, and the current reference value input into a current loop is equal to the current reference value calculated by the voltage loop; the normal operating condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than a current saturation value.

[0007] The application provides a current limiting control method of a network construction device, wherein the network construction device is in a current limiting mode, and the method comprises the following steps: when a current limiting operation condition is met, the network construction device is in the current limiting mode, the input of a voltage loop integrator is zero, and the current reference value input into the current loop is equal to a preset current limiting value; the current limiting operation condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than a current saturation value.

[0008] The application further provides the current limiting control method of the network construction device, and the method further comprises the following steps: when a current limiting exit condition is met, the network construction device exits the current limiting mode according to the result of the detected current; the current limiting exit condition is that after the network construction device is limited for a preset current limiting duration, it is detected that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

[0009] The application further provides the current limiting control method of the network construction device, and the network construction device exits the current limiting mode according to the result of the detected current when the current limiting exit condition is met, which comprises the following steps: when the current limiting exit condition is met, the output side of the voltage loop has no compensation; when the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value, the network construction device exits the current limiting mode; when the amplitude of the current reference value calculated by the voltage loop is greater than the current saturation value, the input of the voltage loop integrator is the negative feedback of the current reference value calculated by the voltage loop, and the current is continuously detected until the detected current value is not greater than the current saturation value, and then the network construction device is controlled to exit the current limiting mode.

[0010] The application further provides the current limiting control method of the network construction device, and the method further comprises the following steps: when the current reference value under the power angle difference is not greater than the current saturation value, a first compensation is added to the output side of the voltage loop; the first compensation is calculated according to a first formula and a second formula; when the current reference value under the power angle difference is greater than the current saturation value, a second compensation is added to the output side of the voltage loop; the second compensation is calculated according to the second formula and a third formula; wherein the first formula is: , the second formula is: , the third formula is: , wherein, k p1 Kp is a proportional coefficient in the voltage loop PI controller, U g Us is a grid voltage, is the initial power angle, is the current saturation value, is the current saturation value, is the voltage reference value of the grid-connected device, Z 1 is the line impedance, R 1 is the resistance of the line impedance, is the angle of the current lagging behind the voltage in the current limiting, d is the angle of the current lagging behind the voltage in the current limiting, X 1 is the reactance of the line impedance.

[0011] The application further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and running on the processor, and the processor implements the current limiting control method of the grid-connected device according to any one of the above when executing the computer program.

[0012] The application further provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program implements the current limiting control method of the grid-connected device according to any one of the above when executed by a processor.

[0013] The application further provides a computer program product, which includes a computer program, and the computer program implements the current limiting control method of the grid-connected device according to any one of the above when executed by a processor.

[0014] The application provides a current limiting control method of a grid-connected device, an electronic device, and a storage medium, and the method includes: when the grid-connected device is in a current limiting mode, adding a compensation amount to an output side of a voltage loop, so that a lower limit of a current limiting exit interval is equal to an initial power angle, and an upper limit of the current limiting exit interval is less than or equal to a current limiting power angle; and the compensation amount is used for correcting a current reference value calculated by the voltage loop. The application can effectively solve the problem of latch-up and repeated switching of mode switching in the current limiting control of the grid-connected device. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0016] Figure 1 is a schematic diagram of the principle of the current limiting control method of the grid-connected device provided by the application.

[0017] Figure 2 is a flowchart of the current limiting control method of the grid-connected device provided by the application.

[0018] Figure 3is the first case provided by the application, the schematic diagram of the power angle and the current reference value curve of the current limiting after adding the compensation amount to the voltage ring output.

[0019] Figure 4 is the second case provided by the application, the schematic diagram of the power angle and the current reference value curve of the current limiting after adding the compensation amount to the voltage ring output.

[0020] Figure 5 is the schematic diagram of the structure of the electronic device provided by the application. DETAILED DESCRIPTION

[0021] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described below in connection with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0022] The double high current system may cause the overcurrent of the power electronic device of the current limiting measure when suffering from the short circuit fault. Since the overcurrent capacity of the power electronic device is far lower than that of the synchronous machine, the overcurrent may cause the damage of the device, and therefore it is necessary to add the current limiting measure in the control of the power electronic device. The current limiting discrimination condition of the existing current limiting control strategy cannot ensure that the grid forming device reasonably exits the current limiting, and may face the problems of latching and repeated switching of mode switching. The latching problem refers to that the grid forming device cannot exit the current limiting mode after the fault ends; the problem of repeated switching of mode switching refers to that the operation mode of the grid forming device is repeatedly switched between the current limiting and the non-current limiting after the fault ends. Both the two problems threaten the normal operation of the grid forming device.

[0023] The present application provides a current limiting control method of a grid forming device, and the purpose is to ensure that the grid forming device adopting the priority control current limiter can quickly exit the current limiting mode and restore the normal grid forming operation mode after the fault recovery. The main principle of the present application is to add a compensation amount to the output of the voltage ring to correct the current reference value when the grid forming device is in the current limiting mode, so that the operation mode in which the grid forming device should be in can be correctly reflected, and the problems of latching and repeated switching of mode can be avoided. When the current reference value is less than or equal to the saturation value, the grid forming device can quickly exit the current limiting mode through the additional current reference value feedback control strategy. The present application firstly proposes the scheme of adding a compensation amount to the output of the voltage ring to correct the current reference value when the current limiting, then gives the calculation method of the compensation amount under two conditions, and then gives the current reference value negative feedback control strategy for making the grid forming device quickly exit the current limiting mode when the current limiting exit condition is met, and finally gives the overall control flow of the control of the current limiting and the state switching.

[0024] The application provides a current limiting control method of grid-forming equipment, comprising: adding a compensation amount to the output side of a voltage loop when the grid-forming equipment is in a current limiting mode, so that the lower limit of a current limiting exit interval is equal to an initial power angle, and the upper limit of the current limiting exit interval is less than or equal to a current limiting power angle; the compensation amount is used to correct a current reference value calculated by the voltage loop.

[0025] Please refer to Figure 1 , Figure 1 The principle schematic diagram of the current limiting control method of the grid-forming equipment provided by the application.

[0026] Please refer to Figure 2 , Figure 2 The flowchart of the current limiting control method of the grid-forming equipment provided by the application.

[0027] In order to solve the problems of latching and repeated switching faced by the grid-forming equipment and ensure that the grid-forming equipment normally exits the current limiting after a fault, the current limiting control method of the grid-forming equipment provided by the application corrects the current reference value by adding a compensation amount to the output of the voltage loop in the current limiting, so that the current reference value is used as a reasonable judgment quantity to determine the exit time of the current limiting and issue an accurate current limiting exit instruction to guide the exit of the current limiting; of course, after the current limiting exit instruction is issued, the feedback control strategy provided by the application is used to make the grid-forming equipment quickly and smoothly exit the current limiting and restore the control strategy of the grid-forming equipment based on the priority control limiter. The advantage of the application is that the problems of latching and repeated switching are solved without constraining other control parameters of the grid-forming equipment, so that the normal operation characteristics of the grid-forming equipment are not affected, the current phase in the current limiting can be adjusted for the improvement of transient stability and voltage response characteristics, and the influence on the problems of latching and repeated switching does not need to be considered.

[0028] If the lower limit of the current limiting exit interval is greater than the initial power angle , the grid-forming equipment may have a latching problem; if the upper limit of the current limiting exit interval is greater than the entering current limiting power angle , the problem of repeated switching may occur. In order to avoid the occurrence of the above two problems, the compensation amount is added to the output side of the voltage loop to adjust the current limiting exit interval, so that the lower limit is equal to , and the upper limit is less than or equal to , thereby solving the problems of latching and repeated switching. The current reference value after adding the compensation term is: , Among them, respectively represent the dq axis current reference value and its amplitude calculated by the voltage loop and the actual current, and respectively represent the dq axis voltage reference value and the actual value of the grid-forming equipment grid connection point,k p1 , k i1 respectively represent the proportional coefficient and the integral coefficient in the voltage loop PI controller, represents the output of the integrator in the voltage loop, represents the filter capacitor, is the rated angular frequency. When , the grid-forming device operates in the normal mode; when , the grid-forming device operates in the current-limiting mode.

[0029] In addition, it needs to be explained that the priority control of current limiting is a common current-limiting strategy for grid-forming devices, which can quickly limit the current and flexibly adjust the phase of the current.

[0030] As a preferred embodiment, it further comprises: when the grid-forming device is in the normal mode, no compensation is added to the output side of the voltage loop.

[0031] In order not to affect the current output of the grid-forming device operating in the normal mode and the judgment of entering the current-limiting mode, when the grid-forming device operates normally, and are 0; when the grid-forming device operates in the current-limiting mode, , adj d and adj q The selection of the two compensation amounts is crucial to solving the problem of latching and repeated switching. The following gives two calculation methods of the two compensation amounts.

[0032] As a preferred embodiment, a compensation amount is added to the output side of the voltage loop, comprising: when the current reference value under the power angle difference is not greater than the current saturation value, a first compensation amount is added to the output side of the voltage loop; the first compensation amount is calculated according to a first formula and a second formula; when the current reference value under the power angle difference is greater than the current saturation value, a second compensation amount is added to the output side of the voltage loop; the second compensation amount is calculated according to the second formula and a third formula; wherein the first formula is: , the second formula is: , the third formula is: , wherein, k p1 is the proportional coefficient in the voltage loop PI controller, U g is the grid voltage, is the initial power angle, is the current-limiting power angle, is the current saturation value, is the voltage reference value of the grid-connected point of the grid-forming device, Z 1 is the line impedance, R 1 is the resistance of the line impedance, is the angle of the current lagging behind the voltage in the current limiting mode, d is the angle of the axis, X 1 is the reactance of the line impedance.

[0033] The interval of under the normal state is denoted as , which corresponds to the interval corresponding to the intersection between the yellow solid line in and the horizontal axis. I The interval of under the current limiting mode is denoted as Figure 3 , which corresponds to the interval corresponding to the intersection between the red solid line in and the horizontal axis. Figure 4 If there is an overlapping area between and O , the converter will repeatedly switch in the overlapping area. I If O does not contain the initial power angle, the converter may not be able to enter O after the fault is removed, resulting in a latching problem. Therefore, by calculating adj d and adj q , there is no overlapping area between O and I , and O contains O . According to the above principle, the values of adj d and adj q have multiple choices, and one calculation method is given below.

[0034] By analyzing the influence of adj d and adj q on O , the system can be divided into two cases for calculation of compensation amount.

[0035] Please refer to Figure 3 , Figure 3 for the first case provided by the present application, the power angle and current reference value curve after adding compensation amount to the voltage ring output under the current limiting mode are shown in the schematic diagram.

[0036] The first case is when (the current reference value under the power angle difference is not greater than the current saturation value), the current limiting exit interval can be equal to by setting the compensation amount. d adj q takes the real part and the imaginary part of respectively. The calculation formula is: , wherein The calculation formula is the first formula. The value is let , The active power output reference value for the converter is taken as 0 to... Solution between them. These represent the line impedance and impedance angle, respectively. Indicates the angle of attack.

[0037] , The formula for calculation is: , The calculation formula is the second formula.

[0038] Calculate adj according to the first and second formulas. d and adj q And applied to the power angle and current limiting curves of grid-type equipment after current loop, from Figure 3 As can be seen from the diagram, the interval corresponding to the intersection of the red curve and the horizontal axis includes... (The blue dot corresponds to the horizontal axis coordinate), and its interval is exactly adjacent to the intersection of the yellow curve and the horizontal axis. This ensures that latch-up and repeated switching problems will not occur.

[0039] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the power angle and current reference value curves in the current limiting process after adding compensation to the voltage loop output in the second case provided by the present invention.

[0040] The second situation is when When the current reference value under the power angle difference is greater than the current saturation value, the current limiting exit range cannot be made exactly equal to the current saturation value by setting the compensation amount. At this point, take the adj. d and adj q Make the lower bound of the rate limiting exit interval as The upper bound is less than or equal to The maximum value is thus achieved, which still ensures that latch-up and repeated switching problems are avoided. d and adj q They are respectively The real and imaginary parts. The calculation formula is: , in, The calculation formula is the second formula. The calculation formula is the third formula.

[0041] Calculate adj based on the second and third formulas. dand adj q and applied to the power angle and current limiting curve of the grid-connected equipment after the current loop, from Figure 4 It can be seen from the red curve that the intersection point with the horizontal axis corresponds to the interval containing (blue point corresponding to the horizontal axis coordinate), and there is no overlapping area between its interval corresponding to the intersection point of the yellow curve with the horizontal axis, so that the latch and repeated switching problem can be ensured not to occur.

[0042] The above method can make the current reference value obtained by the voltage loop in the current limiting become a reasonable judgment basis for exiting the current limiting, thereby avoiding the latch and repeated switching problem caused by the deviation of the current reference value.

[0043] As a preferred embodiment, the grid-connected equipment in the normal mode includes: when the normal operation condition is met, the grid-connected equipment is in the normal mode, the input of the voltage loop integrator is the deviation of the grid-connected point voltage, and the current reference value input to the current loop is equal to the current reference value calculated by the voltage loop; the normal operation condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

[0044] As a preferred embodiment, the grid-connected equipment in the current limiting mode includes: when the current limiting operation condition is met, the grid-connected equipment is in the current limiting mode, the input of the voltage loop integrator is zero, and the current reference value input to the current loop is equal to the preset current limiting value; the current limiting operation condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

[0045] As a preferred embodiment, it further includes: when the current limiting exit condition is met, controlling the grid-connected equipment to exit the current limiting mode according to the current result detected again; the current limiting exit condition is that after the preset current limiting duration of the grid-connected equipment, it is detected that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

[0046] As a preferred embodiment, when the current limiting exit condition is met, controlling the grid-connected equipment to exit the current limiting mode according to the current result detected again, including: when the current limiting exit condition is met, there is no compensation on the output side of the voltage loop; when the amplitude of the current reference value calculated by the voltage loop again is not greater than the current saturation value, the grid-connected equipment exits the current limiting mode; when the amplitude of the current reference value calculated by the voltage loop again is greater than the current saturation value, the input of the voltage loop integrator is the negative feedback of the current reference value calculated by the voltage loop, and the current is continuously detected until the detected current value is not greater than the current saturation value, the grid-connected equipment is controlled to exit the current limiting mode.

[0047] In this embodiment, after the criterion for exiting the current limiting is met, the grid-forming device also needs to quickly exit the current limiting to implement the instruction for exiting the current limiting. In order to realize the quick exit of the current limiting, the application further provides a strategy for quickly exiting the current limiting through feedback control of the current. An example scenario is selected as a three-phase symmetrical short-circuit fault occurring in the power grid, the grid-forming device enters the current limiting mode during the fault, and then the fault is cut off, and the grid-forming device finally exits the current limiting.

[0048] There are three options for the input of the integrator in the grid-forming voltage loop, n =1 is the input selection of the integrator when the grid-forming device is normally operated, that is, the difference between the voltage reference value at the control point and the actual value is taken as the input of the integrator, which is used to control the voltage. n =2 is the input selection of the integrator when the grid-forming device is operated in the current limiting mode and the current limiting exit criterion is not met, at this time, the conditional integration anti-saturation method is adopted, that is, the input of the integrator is set to 0, which is used to avoid the continuous accumulation of the error of the integrator. n =3 is the current limiting quick exit method added by the application, that is, the opposite number of the current reference value of the voltage loop output dq is taken back as the input of the integrator, so that the amplitude of the current reference value obtained by the voltage loop can be quickly reduced to I max and the following, so as to drive the grid-forming device to exit the current limiting.

[0049] In order to reasonably select the input signal of the voltage loop integrator, the overall current limiting control flow is as follows: Suppose that the grid-forming device is initially operated in the normal mode, at this time, the compensation amount of the voltage loop integrator and is set to 0, the input of the voltage loop integrator is selected as the deviation of the grid-connected point voltage ( n =1), the current reference value input into the current loop is equal to the current reference value calculated by the voltage loop, and the grid-forming device is connected to the power grid for operation.

[0050] The size relationship between and is detected. If , the grid-forming device does not enter the current limiting and still works in the normal mode, at this time, and are 0, which is the same as the initial state, and after being calculated by the voltage loop, still holds, then is directly assigned to , the input n of the integral loop remains unchanged, and after being calculated by the voltage loop, the next round of judgment is entered. When a short-circuit fault occurs, will increase in a short time, if Then the network-type equipment will enter the rate-limiting mode. It is determined by the current limiter based on priority control. dq Shaft fixed current Voltage loop integrator input n =2, adjust the compensation amount of the voltage loop output. and They are respectively and .

[0051] After setting the current limiting time for the network-type equipment, the voltage loop is calculated, and the obtained... Continue with Compare. If This indicates that current limiting should be disabled, and the compensation amount output by the voltage loop should be adjusted accordingly. and Set it to 0.

[0052] Perform the voltage loop calculation again and check. and The size relationship. If Then directly Set as Voltage loop integrator input n =1, rate limiting exit; if This will cause the voltage loop integrator input to... n =3, select the integrator input as the negative feedback of the current reference value, so that Rapidly decrease, and continue to compare. and The size relationship, until , and then for , n =1, thus enabling the rate limiting to exit.

[0053] Figure 5 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 5 As shown, the electronic device may include: a processor 501, a communication interface 502, a memory 503, and a communication bus 504. The processor 501, communication interface 502, and memory 503 communicate with each other via the communication bus 504. The processor 501 can call logic instructions in the memory 503 to execute a current-limiting control method for the network-type device. This method includes: when the network-type device is in current-limiting mode, adding a compensation amount to the output side of the voltage loop so that the lower boundary of the current-limiting exit interval is equal to the initial power angle, and the upper boundary of the current-limiting exit interval is less than or equal to the current-limiting power angle; the compensation amount is used to correct the current reference value calculated by the voltage loop.

[0054] Further, the logic instructions in the memory 503 described above can be implemented in the form of software functional units and sold or used as independent products, and can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, and various media that can store program codes.

[0055] In another aspect, the present application also provides a computer program product, which comprises a computer program, the computer program can be stored on a non-transitory computer readable storage medium, and the computer program is executed by a processor, so that the computer can execute the current limiting control method of the network construction type device provided by the above-mentioned method. The method comprises: when the network construction type device is in the current limiting mode, a compensation amount is added to the output side of the voltage loop, so that the lower limit of the current limiting exit interval is equal to the initial power angle, and the upper limit of the current limiting exit interval is less than or equal to the current limiting power angle; the compensation amount is used to modify the current reference value calculated by the voltage loop.

[0056] In another aspect, the present application also provides a non-transitory computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the current limiting control method of the network construction type device provided by the above-mentioned method. The method comprises: when the network construction type device is in the current limiting mode, a compensation amount is added to the output side of the voltage loop, so that the lower limit of the current limiting exit interval is equal to the initial power angle, and the upper limit of the current limiting exit interval is less than or equal to the current limiting power angle; the compensation amount is used to modify the current reference value calculated by the voltage loop.

[0057] The device embodiments described above are only schematic, wherein the units described as separate components can or can not be physically separate, and the components displayed as units can or can not be physical units, that is, they can be located in one place, or distributed on multiple network units. Part or all of the modules can be selected according to actual needs to achieve the purpose of the present embodiment. Those skilled in the art can understand and implement without creative labor.

[0058] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0059] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A current limiting control method for a network-type device, characterized in that, include: When the network-type equipment is in current-limiting mode, a compensation amount is added to the output side of the voltage loop so that the lower limit of the current-limiting exit interval is equal to the initial power angle, and the upper limit of the current-limiting exit interval is less than or equal to the current-limiting power angle; the compensation amount is used to correct the current reference value calculated by the voltage loop.

2. The current limiting control method for network-type equipment according to claim 1, characterized in that, Also includes: When the network-type device is in normal mode, there is no compensation on the output side of the voltage loop.

3. The current limiting control method for network-type equipment according to claim 2, characterized in that, The network-type device is in normal mode, including: When the normal operating conditions are met, the grid-type equipment is in the normal mode, the input of the voltage loop integrator is the deviation of the grid connection point voltage, and the current reference value of the input current loop is equal to the current reference value calculated by the voltage loop; the normal operating condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

4. The current limiting control method for network-type equipment according to claim 1, characterized in that, The network-type device is in rate-limiting mode, including: When the current-limiting operation conditions are met, the network-type device is in the current-limiting mode, the input of the voltage loop integrator is zero, and the current reference value input to the current loop is equal to the preset current-limiting value; the current-limiting operation condition is that the amplitude of the current reference value calculated by the voltage loop is not greater than the current saturation value.

5. The current limiting control method for network-type equipment according to claim 1, characterized in that, Also includes: When the current limiting exit condition is met, the network-type device is controlled to exit the current limiting mode based on the current result detected again; the current limiting exit condition is that after the current limiting of the network-type device is preset for a current limiting time, the amplitude of the current reference value calculated by the voltage loop is detected to be no greater than the current saturation value.

6. The current limiting control method for network-type equipment according to claim 5, characterized in that, The step of controlling the network-type device to exit the current-limiting mode based on the result of a second current detection when the current-limiting exit condition is met includes: When the current limiting exit condition is met, there is no compensation on the output side of the voltage loop; When the amplitude of the current reference value calculated by the voltage loop during the retest is not greater than the current saturation value, the network-type device exits the current limiting mode; When the amplitude of the current reference value calculated by the voltage loop is greater than the current saturation value, the input of the voltage loop integrator is the negative feedback of the current reference value calculated by the voltage loop, and the current is continuously detected until the detected current value is not greater than the current saturation value, at which point the grid-type device is controlled to exit the current limiting mode.

7. The current limiting control method for a network-type device according to any one of claims 1 to 6, characterized in that, The addition of compensation to the output side of the voltage loop includes: When the current reference value under the power angle difference is not greater than the current saturation value, a first compensation amount is added to the output side of the voltage loop; the first compensation amount is calculated according to the first formula and the second formula. When the current reference value under the power angle difference is greater than the current saturation value, a second compensation amount is added to the output side of the voltage loop; the second compensation amount is calculated according to the second formula and the third formula. The first formula is: ， The second formula is: ， The third formula is: ， in, k p1 This refers to the proportional gain in the voltage loop PI controller. U g This is the grid voltage. The initial work angle is... The current-limiting power angle is... The current saturation value is... This is the voltage reference value at the grid connection point for grid-connected equipment. Z 1 represents the line impedance. R 1 represents the resistance of the line impedance. For current limiting, the current lags behind d Angle of axis X 1 represents the reactance of the line impedance.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the current limiting control method for the network-type device as described in any one of claims 1 to 7.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the current limiting control method for the network-type device as described in any one of claims 1 to 7.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the current limiting control method for the network-type device as described in any one of claims 1 to 7.

Images