Ideal no-load direct-current voltage control method and device of inverter and control equipment

Abstract

The invention relates to an ideal no-load direct-current voltage control method and device of an inverter and control equipment. The method comprises the following steps: acquiring a current ideal no-load direct-current voltage of the inverter station, and acquiring an ideal no-load direct-current voltage upper limit and an ideal no-load direct-current voltage lower limit; acquiring a current extinction angle of the inverter station; under the condition that the current ideal no-load direct-current voltage is not greater than the ideal no-load direct-current voltage upper limit and not less than the ideal no-load direct-current voltage lower limit, if the current direct-current voltage of the rectifier station is less than the reference direct-current voltage of the rectifier station and the current extinction angle is less than the reference extinction angle; and if the current gear of the converter transformer tap of the inverter station is not the lowest gear of the converter transformer tap, reducing the current gear of the converter transformer tap so as to adjust the current ideal no-load DC voltage of the inverter station. The method can improve the stability of the power system.

Description

Technical Field

[0001] The present application relates to the technical field of converter transformer tap control in a direct current transmission project, and in particular to a method, device and control equipment for controlling an ideal no-load direct current voltage of an inverter. Background Art

[0002] In traditional technology, the converter tap changer adopts automatic angle control. The converter tap changer monitors the trigger angle of the rectifier station or the arc extinction angle of the inverter station. When the arc extinction angle exceeds the limit, the gear of the converter tap changer is adjusted to control the angle within a fixed range.

[0003] As spot electricity trading continues to advance, the DC power regulation time interval has been reduced from 15 minutes to 5 minutes, and the DC power regulation frequency has increased significantly, resulting in a significant increase in the number of DC engineering converter transformer tap operations, which has reduced the operating life of the converter transformer tap and increased the difficulty of DC operation and maintenance. In order to reduce the number of converter transformer tap operations, the automatic angle control is switched to automatic Udi0 control. Udi0 refers to the ideal no-load DC voltage of the inverter. When Udi0 exceeds the limit, the gear of the converter transformer tap is adjusted to control Udi0 near the rated value.

[0004] However, for DC projects with constant voltage control at the inverter station, there is a situation where the control mode is changed from constant voltage control to fixed arc extinction angle control. Under high power conditions, there is a risk of the DC voltage deviating from the rated value, resulting in the risk of DC current overload operation, affecting the reliability of DC operation. Summary of the invention

[0005] Based on this, it is necessary to provide an ideal no-load DC voltage control method, device, control equipment, computer-readable storage medium and computer program product for the inverter that can improve the reliability of DC operation in order to solve the above technical problems.

[0006] On the one hand, the present application provides an ideal no-load DC voltage control method for an inverter, comprising:

[0007] Obtain the current ideal no-load DC voltage of the inverter station, and obtain the ideal no-load DC voltage upper limit and the ideal no-load DC voltage lower limit;

[0008] Obtaining a current arc extinction angle of the inverter station;

[0009] When the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear position of the converter tap changer of the inverter station is not the lowest gear position of the converter tap changer, the current gear position of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station.

[0010] On the other hand, the present application also provides an ideal no-load DC voltage control device for an inverter, comprising:

[0011] The voltage acquisition module is used to obtain the current ideal no-load DC voltage of the inverter station, and obtain the upper limit and lower limit of the ideal no-load DC voltage;

[0012] An arc extinction angle acquisition module, used to acquire the current arc extinction angle of the inverter station;

[0013] The gear adjustment module is used to reduce the current gear of the converter tap changer to adjust the current ideal no-load DC voltage of the inverter station when the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage; if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear of the converter tap changer of the inverter station is not the lowest gear of the converter tap changer.

[0014] In some embodiments, the gear adjustment module is further used to increase the current gear of the converter tap changer when the current ideal no-load DC voltage is greater than the upper limit of the ideal no-load DC voltage and if the current gear of the converter tap changer is not the highest gear of the converter tap changer.

[0015] In some embodiments, the gear adjustment module is further used to reduce the current gear of the commutation tap changer when the current ideal no-load DC voltage is less than the lower limit of the ideal no-load DC voltage and if the current gear of the commutation tap changer is not the lowest gear of the commutation tap changer.

[0016] In some embodiments, the calculation formula of the current ideal no-load DC voltage is:

[0017]

[0018] in, is the current ideal no-load DC voltage of the inverter station, is the effective value of the AC bus line voltage, is the rated transformation ratio of the converter transformer, is the current position of the converter transformer tap, is the voltage moment of the converter transformer tap, is the ratio of pi. The AC bus refers to the AC bus of the converter transformer.

[0019] In some embodiments, the calculation formula of the ideal no-load DC voltage upper limit includes:

[0020]

[0021] in, is the ideal no-load DC voltage upper limit, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

[0022] In some embodiments, the calculation formula of the lower limit of the ideal no-load DC voltage includes:

[0023]

[0024] in, is the lower limit of the ideal no-load DC voltage, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

[0025] In some embodiments, the calculation formula of the reference DC voltage of the rectifier station includes:

[0026]

[0027] in, is the reference DC voltage of the rectifier station, is the rated value of the DC voltage of the rectifier station, is the reliability coefficient.

[0028] On the other hand, the present application also provides a control device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in the above-mentioned ideal no-load DC voltage control method of the inverter when executing the computer program.

[0029] On the other hand, the present application also provides a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the ideal no-load DC voltage control method of the inverter are implemented.

[0030] On the other hand, the present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the steps in the above-mentioned ideal no-load DC voltage control method of the inverter.

[0031] The ideal no-load DC voltage control method, device, control equipment, computer-readable storage medium and computer program product of the above-mentioned inverter obtain the current ideal no-load DC voltage of the inverter station, and obtain the ideal no-load DC voltage upper limit and the ideal no-load DC voltage lower limit, and obtain the current arc extinction angle of the inverter station. When the current ideal no-load DC voltage is not greater than the ideal no-load DC voltage upper limit and not less than the ideal no-load DC voltage lower limit, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station, the current arc extinction angle is less than the reference arc extinction angle, and the current gear of the converter tap changer of the inverter station is not the lowest gear of the converter tap changer, then the current gear of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station. Since the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station, it indicates that it may have entered the fixed arc extinction angle control mode. When the current arc extinction angle is less than the reference arc extinction angle, it indicates that the current arc extinction angle is small, which also indicates that it may have entered the fixed arc extinction angle control mode. Therefore, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, the current gear of the converter tap changer is reduced, thereby reducing or avoiding the risk of DC current overload operation caused by the DC entering the fixed arc extinction angle control mode, improving the stability of the inverter station, and improving the reliability of DC operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 is an application environment diagram of an ideal no-load DC voltage control method for an inverter in one embodiment;

[0034] Figure 2 1 is a flow chart of an ideal no-load DC voltage control method of an inverter in one embodiment;

[0035] Figure 3 is a flow chart of an ideal no-load DC voltage control method of an inverter in another embodiment;

[0036] Figure 4 is a structural block diagram of an ideal no-load DC voltage control device for an inverter in one embodiment;

[0037] Figure 5 is an internal structure diagram of a control device in one embodiment;

[0038] Figure 6FIG. 4 is a diagram showing the internal structure of a control device in another embodiment. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0040] The ideal no-load DC voltage control method of the inverter provided in the embodiment of the present application can be applied to Figure 1 In the application environment shown. The application environment includes a power system, the power system includes an inverter station and a rectifier station, the inverter station includes a control device and a converter transformer, and the converter transformer includes a converter tap changer. Specifically, the control device can obtain the current ideal no-load DC voltage of the inverter station, and obtain the upper limit of the ideal no-load DC voltage of the inverter station and the lower limit of the ideal no-load DC voltage of the inverter station. The control device obtains the current arc extinction angle of the inverter station. When the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage, and the current ideal no-load DC voltage is not less than the lower limit of the ideal no-load DC voltage, if the DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear of the converter tap changer of the inverter station is not the lowest gear of the converter tap changer, then the current gear of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station.

[0041] The control device may be a terminal or a server. The terminal may be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, IoT devices, and portable wearable devices. IoT devices may be smart speakers, smart TVs, smart air conditioners, smart car devices, projection devices, etc. Portable wearable devices may be smart watches, smart bracelets, head-mounted devices, etc. Head-mounted devices may be virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, etc. The server may be an independent physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides cloud computing services.

[0042] In some embodiments, Figure 2 As shown, a method for controlling an ideal no-load DC voltage of an inverter is provided. Figure 1 The control device in the embodiment is taken as an example to illustrate, and the method includes the following steps 202 to 206. Among them:

[0043] Step 202, obtaining the current ideal no-load DC voltage of the inverter station, and obtaining the upper limit of the ideal no-load DC voltage of the inverter station and the lower limit of the ideal no-load DC voltage of the inverter station.

[0044] Among them, the inverter station is an important power engineering facility in the power system, and its main function is to convert direct current (DC) into alternating current (AC). The current ideal no-load DC voltage of the inverter station refers to the current ideal no-load DC voltage of the inverter station. The upper limit of the ideal no-load DC voltage of the inverter station is greater than the rated value of the ideal no-load DC voltage of the inverter station, and the lower limit of the ideal no-load DC voltage of the inverter station is less than the rated value of the ideal no-load DC voltage of the inverter station. Among them, the default control mode of the inverter station is a constant voltage control mode. When the inverter station is in a special working condition, the inverter station may enter the fixed arc extinction angle control mode from the constant voltage control mode. Since the risk of DC current overload operation is prone to occur in the fixed arc extinction angle control mode, in order to avoid or reduce the entry into the fixed arc extinction angle control mode, the ideal no-load DC voltage control method of the inverter of the present application is proposed.

[0045] The upper limit of the ideal no-load DC voltage is greater than the rated value of the ideal no-load DC voltage of the inverter station, and the lower limit of the ideal no-load DC voltage is less than the rated value of the ideal no-load DC voltage of the inverter station. The current ideal no-load DC voltage of the inverter station can be expressed as It means that the ideal no-load DC voltage upper limit of the inverter station can be expressed as The ideal no-load DC voltage lower limit of the inverter station can be expressed as The rated value of the ideal no-load DC voltage of the inverter station can be expressed as express. It can be set according to actual needs, for example, it can be determined during the DC engineering design stage. , .

[0046] Step 204, obtaining the current arc extinction angle of the inverter station.

[0047] The current arc extinction angle of the inverter station refers to the current arc extinction angle of the inverter station.

[0048] Step 206, when the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear position of the converter tap changer of the inverter station is not the lowest gear position of the converter tap changer, then the current gear position of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station.

[0049] Among them, the change of the gear position of the commutation transformer tap change will cause the change of the ideal no-load DC voltage of the inverter. When the ideal no-load DC voltage of the inverter is unreasonable or unstable, the gear position of the commutation transformer tap can be adjusted.

[0050] The current DC voltage of the rectifier station can be Indicates that the reference DC voltage of the rectifier station can be Indicates that the current gear of the commutation transformer tap changer can be Indicates that the lowest gear of the converter tap changer can be used Indicates that the highest gear of the converter tap changer can be used express, and It can be set according to actual needs, for example, it can be determined in the DC engineering design stage. Not greater than means less than or equal to, and not less than means greater than or equal to. The converter tap changer has multiple optional gears, the highest gear among the multiple gears is , the lowest gear is , current gear It is any one of the multiple gears.

[0051] The reference DC voltage of the rectifier station is less than the rated DC voltage of the rectifier station. The rated DC voltage of the rectifier station can be Indicates that Less than .

[0052] The current arc extinction angle can be used The reference arc extinction angle can be expressed as It means that when the current arc extinction angle is less than the reference arc extinction angle, it indicates that the mode switching probability reaches the probability threshold. The probability threshold can be set as needed, for example, it can be 90% or 95%. The mode switching probability refers to the probability that the inverter changes from a constant voltage control mode to a fixed arc extinction angle control mode. The reference arc extinction angle can be set according to actual needs. For example, the reference arc extinction angle can range from [17.5°, 19°]. For example, the reference arc extinction angle can be 16.7°.

[0053] Specifically, in and In the case of as well as ,and , the control device may issue a first gear reduction instruction to reduce the current gear of the commutation tap changer. The first gear reduction instruction may be an instruction to reduce a gear or an instruction to reduce to a specified gear. , then return to step 202 to repeat steps 202-206.

[0054] In the ideal no-load DC voltage control method of the above-mentioned inverter, the current ideal no-load DC voltage of the inverter station is obtained, and the ideal no-load DC voltage upper limit and the ideal no-load DC voltage lower limit are obtained, and the current arc extinction angle of the inverter station is obtained. When the current ideal no-load DC voltage is not greater than the ideal no-load DC voltage upper limit and not less than the ideal no-load DC voltage lower limit, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station, the current arc extinction angle is less than the reference arc extinction angle, and the current gear position of the converter tap changer of the inverter station is not the lowest gear position of the converter tap changer, the current gear position of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station. Since the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station, it indicates that it may have entered the fixed arc extinction angle control mode. When the current arc extinction angle is less than the reference arc extinction angle, it indicates that the current arc extinction angle is small, which also indicates that it may have entered the fixed arc extinction angle control mode. Therefore, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, the current gear of the converter tap changer is reduced, thereby reducing or avoiding the risk of DC current overload operation caused by the DC entering the fixed arc extinction angle control mode, improving the stability of the inverter station, and improving the reliability of DC operation.

[0055] In some embodiments, the method further includes: when the current ideal no-load DC voltage is greater than the upper limit of the ideal no-load DC voltage, if the current gear of the commutation tap changer is not the highest gear of the commutation tap changer, then increasing the current gear of the commutation tap changer.

[0056] Among them, if , then it means abnormal.

[0057] Specifically, in In the case of , the control device can issue a gear-up command to increase the current gear of the commutation transformer. The gear-up command can be a command to increase a gear or a command to increase to a specified gear. , then return to step 202 to repeat steps 202-206.

[0058] In this embodiment, and In this case, the current gear of the converter tap changer is increased, thereby reducing the risk of DC current overload operation caused by the DC entering the fixed arc extinction angle control mode, improving the stability of the inverter station and the reliability of DC operation.

[0059] In some embodiments, the method further includes: when the current ideal no-load DC voltage is less than the lower limit of the ideal no-load DC voltage, if the current gear position of the converter tap changer of the inverter station is not the lowest gear position of the converter tap changer, then reducing the current gear position of the converter tap changer.

[0060] Among them, if , then it means abnormal.

[0061] Specifically, in In the case of , the control device may issue a second gear reduction instruction to reduce the current gear of the commutation tap changer. The second gear increase instruction may be an instruction to reduce a gear or an instruction to reduce to a specific gear. , then return to step 202 to repeat steps 202-206.

[0062] In this embodiment, and In this case, the current gear of the converter tap changer is reduced, thereby reducing the risk of DC current overload operation caused by the DC entering the fixed arc extinction angle control mode, improving the stability of the inverter station and the reliability of DC operation.

[0063] In some embodiments, the calculation formula of the current ideal no-load DC voltage of the inverter station includes:

[0064]

[0065] in, is the current ideal no-load DC voltage of the inverter station, It is the effective value of the AC bus line voltage. The unit of the effective value of the AC bus line voltage can be but is not limited to KV (kilovolt). is the rated transformation ratio of the converter transformer, is the current gear position of the commutation transformer tap changer, is the voltage moment of the commutation transformer tap, is the ratio of pi. The converter tap is the converter transformer tap.

[0066] In an inverter station, the AC bus refers to the bus connected to the output end of the inverter, which is used to transmit the AC power output by the inverter to the power grid or other loads. The rated transformation ratio of a transformer refers to the ratio of the main tap voltage of the high and medium voltage windings of the transformer to the rated voltage of the low voltage winding. For example, a 220V (volt) / 110V transformer has a rated transformation ratio of 2:1. The voltage moment (%) of the converter transformer tap refers to the voltage difference between adjacent gears of the converter transformer tap.

[0067] In this embodiment, the current ideal no-load DC voltage of the inverter station is accurately calculated based on the effective value of the AC bus line voltage, the rated transformation ratio of the converter transformer, the current gear position of the converter transformer tap changer, and the voltage gear moment of the converter transformer tap changer.

[0068] In some embodiments, the calculation formula of the ideal no-load DC voltage upper limit includes:

[0069]

[0070] in, is the ideal no-load DC voltage upper limit of the inverter station, It is the rated value of the ideal no-load DC voltage of the inverter station. It can be set according to actual needs, for example, it can be determined during the DC engineering design stage. is a decimal between 0 and 1, and Close to 0, for example, It can be 0.01.

[0071] In this embodiment, the calculation formula of the ideal no-load DC voltage upper limit can ensure It is close to and greater than the rated value of the ideal no-load DC voltage of the inverter station, thereby improving the accuracy of the upper limit of the ideal no-load DC voltage.

[0072] In some embodiments, the calculation formula of the ideal no-load DC voltage lower limit includes:

[0073]

[0074] in, is the lower limit of the ideal no-load DC voltage, is the rated value of the ideal no-load DC voltage of the inverter station, It can be set according to actual needs, for example, it can be determined in the DC engineering design stage. is a decimal between 0 and 1, and Close to 0, for example, It can be 0.01.

[0075] In this embodiment, the calculation formula of the ideal no-load DC voltage lower limit can ensure It is close to and smaller than the rated value of the ideal no-load DC voltage of the inverter station, thereby improving the accuracy of the lower limit of the ideal no-load DC voltage.

[0076] In some embodiments, the calculation formula of the reference DC voltage of the rectifier station includes:

[0077]

[0078] in, is the reference DC voltage of the rectifier station, is the rated DC voltage of the rectifier station, is the reliability coefficient. is a decimal between 0 and 1, and is close to 1. For example, has a value range of [0.99, 0.999]. For example, can be 0.995.

[0079] In this embodiment, the calculation formula of the reference DC voltage of the rectifier station can ensure that is less than and close to the rated DC voltage of the rectifier station, improving the accuracy of the reference DC voltage of the rectifier station.

[0080] In some embodiments, as Figure 3 shown, a schematic flowchart of an ideal no-load DC voltage control method for an inverter is provided, including:

[0081] Step 1: Calculate the current ideal no-load DC voltage Udi0 of the inverter station.

[0082] Step 2: Calculate the current extinction angle γ of the inverter station.

[0083] Step 3: Determine whether Udi0 > Udi0_max is satisfied. If satisfied, go to Step 6; if not, go to Step 5.

[0084] Step 4: Determine whether Udi0 < Udi0_min is satisfied. If satisfied, go to Step 7; if not, go to Step 5.

[0085] Step 5: Determine whether the current DC voltage UDL_rec of the rectifier station < k * UDL_n and the extinction angle γ < γ_set are satisfied. If satisfied, go to Step 7; if not, go to Step 1.

[0086] Step 6: Determine whether the current gear TCP = TCP_max is satisfied. If satisfied, go to Step 1; if not, go to Step 8.

[0087] Step 7: Determine whether the current gear TCP = TCP_min is satisfied. If satisfied, go to Step 1; if not, go to Step 9.

[0088] Step 8: Increase the tap position of the converter transformer, that is, increase the current tap position of the converter transformer.

[0089] Step 9: Decrease the tap position of the converter transformer, that is, decrease the current tap position of the converter transformer.

[0090] In this embodiment, by adjusting the tap position of the converter transformer, the risk of overloading of DC current caused by the DC entering the fixed extinction angle control mode can be reduced, which is used for the tap control of the converter transformer in the inverter station, and the DC operation reliability can be improved. Moreover, the principle of the ideal no-load DC voltage control method for the inverter provided by this application is simple, with small calculation amount and small program modification amount, and has strong engineering practical value.

[0091] For example, taking Tian-Guang DC as an example, under a certain operating condition, the DC operates monopolarly with an operating power of 900 MW. The current DC voltage UDL_rec of the rectifier is 495.2 kV, the firing angle is 16.7°, the DC voltage of the inverter is 466.1 kV, the extinction angle γ is 16.7°, the current tap position TCP of the converter transformer is at tap 2, Uac = 230 kV, k t = 1.16, DK1 = DK2 = DK = 1%, Udi0_n = 268 kV, Udi0_max = 270.68 kV, Udi0_min = 265.32 kV, k = 0.995, UDL_n = 500 kV, γ_set = 18°, TCP_max = 12, TCP_min = 1.

[0092] Accordingly, the ideal no-load DC voltage control method for the corresponding inverter includes the following steps:

[0093] Step 1: Calculate the ideal no-load DC voltage Udi0 of the inverter station, which is 268.07 kV.

[0094] Step 2: Calculate the extinction angle γ of the inverter station, which is 16.7°.

[0095] Step 3: If Udi0 > Udi0_max is not satisfied, go to Step 5.

[0096] Step 4: If Udi0 < Udi0_min is not satisfied, go to Step 5.

[0097] Step 5: If UDL_rec < k * UDL_n and the extinction angle γ < γ_set are satisfied, go to Step 7.

[0098] Step 7: If TCP = TCP_min is not satisfied, go to Step 9.

[0099] Step 9: Lower the tap position of the converter transformer.

[0100] The ideal no-load DC voltage control method of the inverter provided in this application actually realizes a control method for the inverter station commutator tap changer Udi0 suitable for fixed voltage control of the inverter station, which can reduce the risk of DC current overload operation caused by DC entering the fixed arc extinction angle control mode, and improve the stability of the inverter station. It can improve the automation and intelligence level of DC transmission project operation, avoid DC entering the fixed arc extinction angle control mode, and avoid the risk of DC current overload operation caused by DC entering the fixed arc extinction angle control mode.

[0101] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0102] Based on the same inventive concept, the embodiment of the present application also provides an ideal no-load DC voltage control device for an inverter for implementing the ideal no-load DC voltage control method for the inverter involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the ideal no-load DC voltage control device for one or more inverters provided below can refer to the limitations of the ideal no-load DC voltage control method for the inverter above, and will not be repeated here.

[0103] In some embodiments, Figure 4 As shown, an ideal no-load DC voltage control device for an inverter is provided, comprising: a voltage acquisition module 402, an arc extinction angle acquisition module 404 and a gear adjustment module 406, wherein:

[0104] The voltage acquisition module 402 is used to acquire the current ideal no-load DC voltage of the inverter station, and acquire the upper limit of the ideal no-load DC voltage of the inverter station and the lower limit of the ideal no-load DC voltage of the inverter station.

[0105] The arc extinction angle acquisition module 404 is used to acquire the current arc extinction angle of the inverter station.

[0106] The gear adjustment module 406 is used to reduce the current gear of the commutation tap changer to adjust the current ideal no-load DC voltage of the inverter station when the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear of the commutation tap changer of the inverter station is not the lowest gear of the commutation tap changer.

[0107] In some embodiments, the gear adjustment module is further used to increase the current gear of the commutation tap changer when the current ideal no-load DC voltage is greater than the upper limit of the ideal no-load DC voltage and if the current gear of the commutation tap changer is not the highest gear of the commutation tap changer.

[0108] In some embodiments, the gear adjustment module is further used to reduce the current gear of the converter tap changer if the current gear of the converter tap changer of the inverter station is not the lowest gear of the converter tap changer when the current ideal no-load DC voltage is less than the lower limit of the ideal no-load DC voltage.

[0109] In some embodiments, the calculation formula of the current ideal no-load DC voltage is:

[0110]

[0111] in, is the current ideal no-load DC voltage of the inverter station, is the effective value of the AC bus line voltage, is the rated transformation ratio of the converter transformer, is the current position of the converter transformer tap, is the voltage moment of the converter transformer tap, is the ratio of pi.

[0112] In some embodiments, the calculation formula of the ideal no-load DC voltage upper limit includes:

[0113]

[0114] in, is the ideal no-load DC voltage upper limit of the inverter station, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

[0115] In some embodiments, the calculation formula of the ideal no-load DC voltage lower limit includes:

[0116]

[0117] in, is the lower limit of the ideal no-load DC voltage, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

[0118] In some embodiments, the calculation formula of the reference DC voltage of the rectifier station includes:

[0119]

[0120] in, is the reference DC voltage of the rectifier station, is the DC voltage rating of the rectifier station, is the reliability coefficient, A decimal between 0 and 1.

[0121] Each module in the ideal no-load DC voltage control device of the inverter can be implemented in whole or in part by software, hardware and a combination thereof. Each module can be embedded in or independent of a processor in a control device in the form of hardware, or can be stored in a memory in the control device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0122] In some embodiments, a control device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 5 As shown. The control device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the control device is used to provide computing and control capabilities. The memory of the control device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the control device is used to store data related to the ideal no-load DC voltage control method of the inverter. The input / output interface of the control device is used to exchange information between the processor and an external device. The communication interface of the control device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, an ideal no-load DC voltage control method of an inverter is implemented.

[0123] In some embodiments, a control device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 6As shown. The control device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the control device is used to provide computing and control capabilities. The memory of the control device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the control device is used to exchange information between the processor and the external device. The communication interface of the control device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be realized through WIFI, a mobile cellular network, near field communication (Near Field Communication, NFC) or other technologies. When the computer program is executed by the processor, an ideal no-load DC voltage control method of an inverter is realized. The display unit of the control device is used to form a visually visible picture, which can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen, and the input device of the control device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the control device shell, or an external keyboard, touchpad or mouse.

[0124] Those skilled in the art will appreciate that Figure 5 and 6 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the control device to which the scheme of the present application is applied. The specific control device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0125] In some embodiments, a control device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0126] In some embodiments, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above embodiments are implemented.

[0127] In some embodiments, a computer program product is provided, including a computer program, which implements the steps in the above embodiments when executed by a processor.

[0128] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0129] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0130] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. An ideal no-load DC voltage control method for an inverter, characterized in that: The method comprises: Obtaining a current ideal no-load DC voltage of an inverter station, and obtaining an upper limit of the ideal no-load DC voltage of the inverter station and a lower limit of the ideal no-load DC voltage of the inverter station; Obtaining a current arc extinction angle of the inverter station; When the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage, if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear position of the converter tap changer of the inverter station is not the lowest gear position of the converter tap changer, the current gear position of the converter tap changer is reduced to adjust the current ideal no-load DC voltage of the inverter station.

2. The method according to claim 1, characterized in that The method further comprises: When the current ideal no-load DC voltage is greater than the upper limit of the ideal no-load DC voltage, if the current gear position of the converter tap changer is not the highest gear position of the converter tap changer, the current gear position of the converter tap changer is increased.

3. The method according to claim 1, characterized in that The method further comprises: When the current ideal no-load DC voltage is less than the lower limit of the ideal no-load DC voltage, if the current gear position of the commutation tap changer is not the lowest gear position of the commutation tap changer, the current gear position of the commutation tap changer is reduced.

4. The method according to claim 1, characterized in that: The calculation formula of the current ideal no-load DC voltage of the inverter station includes: in, is the current ideal no-load DC voltage of the inverter station, is the effective value of the AC bus line voltage, is the rated transformation ratio of the converter transformer, is the current gear position of the commutation transformer tap changer, is the voltage moment of the commutation transformer tap, is the ratio of pi.

5. The method according to claim 1, characterized in that The calculation formula of the ideal no-load DC voltage upper limit includes: in, is the ideal no-load DC voltage upper limit of the inverter station, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

6. The method according to claim 1, characterized in that The calculation formula of the lower limit of the ideal no-load DC voltage includes: in, is the lower limit of the ideal no-load DC voltage, is the rated value of the ideal no-load DC voltage of the inverter station, A decimal between 0 and 1.

7. The method according to claim 1, characterized in that The calculation formula of the reference DC voltage of the rectifier station includes: in, is the reference DC voltage of the rectifier station, is the DC voltage rating of the rectifier station, is the reliability coefficient, A decimal between 0 and 1.

8. An ideal no-load DC voltage control device for an inverter, characterized in that: The device comprises: A voltage acquisition module is used to acquire the current ideal no-load DC voltage of the inverter station, and acquire the upper limit of the ideal no-load DC voltage of the inverter station and the lower limit of the ideal no-load DC voltage of the inverter station; An arc extinction angle acquisition module, used to acquire the current arc extinction angle of the inverter station; The gear adjustment module is used to reduce the current gear of the converter tap changer to adjust the current ideal no-load DC voltage of the inverter station when the current ideal no-load DC voltage is not greater than the upper limit of the ideal no-load DC voltage and not less than the lower limit of the ideal no-load DC voltage; if the current DC voltage of the rectifier station is less than the reference DC voltage of the rectifier station and the current arc extinction angle is less than the reference arc extinction angle, and the current gear of the converter tap changer of the inverter station is not the lowest gear of the converter tap changer.

9. A control device, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

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 steps of the method according to any one of claims 1 to 7 are implemented.

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