Method and device for determining boundary parameters of SVG (static var generator) steady-state operation

Abstract

The invention provides an SVG steady-state operation boundary parameter determination method and device, and relates to the technical field of data processing. The method comprises the following steps: determining a first target voltage per unit value sent by the SVG under a power frequency; according to the type of the current emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, determining the system short-circuit ratio of the SVG electromagnetic transient simulation scene capable of enabling the SVG to normally emit the rated current; and obtaining a second target voltage per unit value according to an expression of the impedance ratio of the SVG under low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determining the system short-circuit ratio of the SVG electromagnetic transient simulation scene and the second target voltage per unit value as boundary parameters of SVG steady-state operation. The device executes the method. According to the method and the device provided by the embodiment of the invention, the steady-state operation of the SVG can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of data processing, and in particular to a method and device for determining boundary parameters of SVG steady-state operation. Background Art

[0002] SVG, or reactive power compensator, is a new type of equipment suitable for low-frequency power generation and transmission systems represented by 50 / 3Hz and 20Hz. To ensure the steady-state operation of SVG, the existing technology needs to set the boundary parameters of SVG steady-state operation based on the reactive current output capacity of SVG at low frequency, which is the same as that at industrial frequency.

[0003] However, the above-mentioned prior art does not take into account the important influence of certain parameters in low-frequency scenarios, so that the boundary parameter determination method of SVG steady-state operation relies on manual experience setting, and the set values ​​are not reasonable, thereby affecting the steady-state operation of SVG. Summary of the invention

[0004] In view of the problems in the prior art, the embodiments of the present invention provide a method and device for determining boundary parameters of SVG steady-state operation, which can at least partially solve the problems in the prior art.

[0005] In one aspect, the present invention provides a method for determining boundary parameters of SVG steady-state operation, comprising:

[0006] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0007] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0008] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0009] The step of determining a first target voltage per unit value emitted by the SVG at the power frequency includes:

[0010] According to the voltage value ranges corresponding to the current types, first target voltage per unit values ​​corresponding to the current types are determined.

[0011] Wherein, the current type includes inductive current; accordingly, determining the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value includes:

[0012] If it is determined that the current type is the inductive current, calculating the difference between the external equivalent voltage and the first target voltage per unit value to obtain a first voltage difference;

[0013] The ratio of the first voltage difference to the first per-unit value of the inductive reactance of the SVG at the power frequency is calculated to obtain a first current ratio, and the reciprocal of the first current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

[0014] Wherein, the current type includes capacitive current; accordingly, determining the system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value includes:

[0015] If it is determined that the current type is the capacitive current, calculating the difference between the first target voltage per unit value and the external equivalent voltage to obtain a second voltage difference;

[0016] The ratio of the second voltage difference to the first per-unit value of the capacitive reactance of the SVG at the power frequency is calculated to obtain a second current ratio, and the reciprocal of the second current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

[0017] The step of obtaining the second target voltage per unit value based on the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value comprises:

[0018] Substituting the first target voltage per unit value, the power frequency value and the low frequency value into the following expression, a first expression to be solved is obtained:

[0019]

[0020] Wherein, K is the impedance ratio, is the first target voltage per unit value, is the second target voltage per unit value, ω1 is the power frequency value, ω2 is the low frequency value, and sqrt represents square root;

[0021] Taking the denominator of the first expression to be solved being greater than zero as a first constraint condition, a target voltage numerical value range of the second target voltage per unit value is obtained.

[0022] The method for determining boundary parameters of SVG steady-state operation further includes:

[0023] Obtain an impedance ratio value, substitute the impedance ratio value, the first target voltage per unit value, the power frequency value and the low frequency value into the expression to obtain a second expression to be solved;

[0024] The equality of the second expression to be solved is established as a second constraint condition to obtain a target voltage value of the second target voltage per unit value.

[0025] Wherein, the low frequency value is 20 Hz or 50 / 3 Hz.

[0026] In one aspect, the present invention provides a device for determining boundary parameters of SVG steady-state operation, comprising:

[0027] A first determining unit, used to determine a first target voltage per unit value emitted by the SVG at an industrial frequency;

[0028] A second determination unit is used to determine a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value;

[0029] The third determination unit is used to obtain the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determine the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value as boundary parameters of the steady-state operation of SVG.

[0030] In another aspect, an embodiment of the present invention provides an electronic device, including: a processor, a memory, and a bus, wherein:

[0031] The processor and the memory communicate with each other via the bus;

[0032] The memory stores program instructions that can be executed by the processor, and the processor calls the program instructions to execute the following method:

[0033] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0034] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0035] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0036] An embodiment of the present invention provides a non-transitory computer-readable storage medium, including:

[0037] The non-transitory computer-readable storage medium stores computer instructions, which cause the computer to execute the following method:

[0038] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0039] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0040] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0041] The method and device for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention determine a first target voltage per unit value emitted by SVG at power frequency; determine the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that can enable SVG to normally emit rated current according to the current type emitted by SVG, the external equivalent voltage of SVG and the first target voltage per unit value; obtain the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determine the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value as boundary parameters of SVG steady-state operation. By taking the impedance ratio of SVG at low frequency as the main influencing factor affecting the steady-state operation of SVG and automatically determining quantifiable boundary parameters, the steady-state operation of SVG can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0043] Figure 1 It is a flowchart of a method for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention.

[0044] Figure 2 It is a schematic diagram illustrating the phase relationship provided by an embodiment of the present invention.

[0045] Figure 3 It is a structural schematic diagram of a device for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention.

[0046] Figure 4 A schematic diagram of the physical structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention. It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other arbitrarily.

[0048] Reactive power compensator is a compensation device. Its role in the electronic power supply system is to improve the power factor of the power grid, reduce the loss of power supply transformers and transmission lines, improve power supply efficiency, and improve the power supply environment. Therefore, reactive power compensation devices are in an indispensable and very important position in the power supply system. Reasonable selection of compensation devices can minimize network losses and improve the quality of the power grid. On the contrary, improper selection or use may cause many factors such as power supply system, voltage fluctuations, and increased harmonics.

[0049] There are three sampling modes for reactive power compensation controllers: power factor type, reactive power type, and reactive current type. Choosing a physical control mode is actually choosing a reactive power compensation controller. The controller is the command system of the reactive power compensation device. Sampling, calculation, sending switching signals, parameter setting, measurement, component protection and other functions are all completed by the compensation controller.

[0050] Figure 1 FIG. 1 is a flow chart of a method for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention. Figure 1 As shown, the method for determining boundary parameters of SVG steady-state operation provided by the embodiment of the present invention includes:

[0051] Step S1: determining a first target voltage per unit value emitted by SVG at a power frequency.

[0052] Step S2: determining the system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit the rated current according to the type of current emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value.

[0053] Step S3: According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, obtain the second target voltage per unit value, and determine the SVG electromagnetic transient simulation scenario system short-circuit ratio and the second target voltage per unit value as boundary parameters for the steady-state operation of SVG.

[0054] In the above step S1, the device determines the first target voltage per unit value emitted by the SVG at the power frequency. The device may be a computer device that executes the method, for example, a server. It should be noted that the acquisition and analysis of data involved in the embodiment of the present invention are authorized by the user. The power frequency value is 50Hz.

[0055] The determining of a first target voltage per unit value emitted by the SVG at the power frequency comprises:

[0056] According to the voltage value ranges corresponding to the current types, the first target voltage per unit values ​​corresponding to the current types are determined. The current types include inductive currents, and the voltage value range corresponding to them is [0.9, 1.0], and the unit is a multiple, which indicates the multiple of the standard per unit value. A value can be arbitrarily selected from the above range as the first target voltage per unit value when the SVG emits an inductive current.

[0057] The current type includes capacitive current, and the corresponding voltage value range is [1.0, 1.1], and the unit is multiple, indicating the multiple of the standard per unit value. A value can be arbitrarily selected from the above range as the first target voltage per unit value when the SVG emits capacitive current.

[0058] In the above step S2, the device determines the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value. The current type includes inductive current; accordingly, the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value includes:

[0059] If it is determined that the current type is the inductive current, calculating the difference between the external equivalent voltage and the first target voltage per unit value to obtain a first voltage difference;

[0060] The ratio of the first voltage difference to the first per-unit value of the inductive reactance of the SVG at the power frequency is calculated to obtain a first current ratio, and the reciprocal of the first current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

[0061] The current type includes capacitive current; accordingly, determining the system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value, includes:

[0062] If it is determined that the current type is the capacitive current, calculating the difference between the first target voltage per unit value and the external equivalent voltage to obtain a second voltage difference;

[0063] The ratio of the second voltage difference to the first per-unit value of the capacitive reactance of the SVG at the power frequency is calculated to obtain a second current ratio, and the reciprocal of the second current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

[0064] Take inductive current as an example and select The instructions are as follows:

[0065] If the external equivalent voltage of SVG Then the first voltage difference = 0.1, and the first per unit inductive reactance value of SVG at power frequency can be calculated according to the following formula:

[0066]

[0067] in, is the first inductive reactance per unit value, P N For the same rated capacity of SVG, U N is the same rated voltage of SVG, that is, the rated capacity and rated voltage are the same at power frequency and low frequency. ω1 is the power frequency value, L is the equivalent inductance of the SVG electromagnetic transient simulation scenario system at power frequency and low frequency, which are the same equivalent inductance values. For example, the above formula can be used to calculate The first current ratio = 0.1, and then the SVG electromagnetic transient simulation scenario system short-circuit ratio = 10. It can be determined that when SCR ≥ 10, the SVG can normally output the rated current.

[0068] The capacitive current will not be described in detail.

[0069] In the above step S3, the device obtains the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determines the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value as boundary parameters for the steady-state operation of SVG.

[0070] The step of obtaining the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value comprises:

[0071] Substituting the first target voltage per unit value, the power frequency value and the low frequency value into the following expression, a first expression to be solved is obtained:

[0072]

[0073] Wherein, K is the impedance ratio, is the first target voltage per unit value, is the second target voltage per unit value, ω1 is the power frequency value, ω2 is the low frequency value, and sqrt represents square root;

[0074] Taking the denominator of the first expression to be solved as greater than zero as the first constraint condition, the target voltage value range of the second target voltage per unit value is obtained. Taking the first target voltage per unit value of 0.9 as an example, substituting it into the above formula, the following can be obtained:

[0075]

[0076] Taking the low frequency value of 20Hz as an example,

[0077] Substituting into the above formula, we can get the first expression to be solved as follows:

[0078]

[0079] Since the content of the square root should be greater than or equal to zero, and the denominator of the square root in the first expression to be solved should not be equal to zero, the problem to be solved is transformed into:

[0080]

[0081] Keep positive numbers is the target voltage value range, when The closer it is to 0.9448, the larger K is.

[0082] The method for determining boundary parameters of SVG steady-state operation also includes:

[0083] Obtain an impedance ratio value, substitute the impedance ratio value, the first target voltage per unit value, the power frequency value and the low frequency value into the expression to obtain a second expression to be solved;

[0084] The second constraint condition is that the second expression to be solved is satisfied, and the target voltage value of the second target voltage per unit value is obtained. Referring to the above description, the difference between the second expression to be solved and the first expression to be solved is that K is a known value. At this time, the problem to be solved is transformed into solving the following equation to be satisfied, and A positive target voltage value:

[0085]

[0086] Therefore, in the current low-frequency scenario where K is uncertain, by analogy with the normal operation of SVG in the power frequency scenario where SCR ≥ 10, it can be obtained that in a 20Hz low-frequency system, if SVG emits inductive current, the low-frequency steady-state operating voltage is the inductive operating boundary of 0.9448. When the K value is clear, it is also necessary to combine the K value and the expression to Boundary constraints.

[0087] Taking the low frequency value of 50 / 3Hz as an example,

[0088] Substituting the corresponding formulas above, we can get the first expression to be solved as follows:

[0089]

[0090] Since the content of the square root should be greater than or equal to zero, and the denominator of the square root in the first expression to be solved should not be equal to zero, the problem to be solved is transformed into:

[0091]

[0092] Keep positive numbers is the target voltage value range, when The closer it is to 0.9667, the larger K is.

[0093] Referring to the above description, the difference between the second expression to be solved and the first expression to be solved is that K is a known value. At this time, the problem to be solved is transformed into solving the following equation, and A positive target voltage value:

[0094]

[0095] Therefore, in the current low-frequency scenario where K is uncertain, by analogy with the normal operation of SVG in the power frequency scenario where SCR ≥ 10, it can be obtained that in a 50 / 3Hz low-frequency system, if SVG emits inductive current, the low-frequency steady-state operating voltage is the inductive operating boundary of 0.9667. When the K value is clear, it is also necessary to combine the K value and the expression to Boundary constraints.

[0096] right The reasoning process is as follows: 1. Derivation of the steady-state voltage operating boundary under the same current output capacity in the low-frequency scenario:

[0097] According to the operating characteristics of SVG, SVG should achieve the same current output capacity in power frequency and low frequency scenarios, so the following vector relationship is obtained:

[0098]

[0099] in, is the external equivalent voltage of SVG, is the voltage vector value emitted by the power frequency SVG, is the voltage vector value emitted by the low-frequency SVG, is the current vector value emitted by the industrial frequency SVG, is the current vector value emitted by the low-frequency SVG, L is the equivalent inductance of the SVG electromagnetic transient simulation scenario system at power frequency and low frequency, which are the same equivalent inductance value, and R is the equivalent resistance of the SVG electromagnetic transient simulation scenario system at power frequency and low frequency, which are the same equivalent resistance value.

[0100] Because SVG is actually running, and and The phase relationship is maintained at ±90°. Taking the phase relationship maintained at 90° as an example, the phase relationship diagram can be obtained, such as Figure 2 shown.

[0101] According to the vector relationship expression and Figure 2 , using the standard processing, we can get the following relationship:

[0102]

[0103] in, Substitute 1 for the value of is the first per unit inductive reactance of SVG at power frequency, is the second inductive reactance per unit value of SVG at low frequency, and θ is the impedance angle.

[0104] We can further get the following expression:

[0105]

[0106] 2. Derivation of the relationship between impedance ratio and operating voltage:

[0107] The impedance ratio of the low-frequency system is defined as get

[0108] Assuming that the system short-circuit ratio in the SVG electromagnetic transient simulation scenario is SCR=m, the following can be deduced based on the definition of short-circuit ratio:

[0109]

[0110] Since SVG equipment is a current source control device, SVG equipment with the same rated capacity and rated voltage should achieve the same reactive current support capability at power frequency and low frequency. Therefore, we can get:

[0111]

[0112] In the existing power frequency transmission system, the reactance-to-resistance ratio (X / R) of the external equivalent system of the SVG grid-connected power grid often ignores the effect of the system equivalent resistance. However, in the low-frequency transmission system, the equivalent reactance will decrease as the frequency decreases. In the power frequency scenario, the impedance ratio will greatly affect the SVG's steady-state operating current output capacity. Therefore, the existing method for setting boundary parameters is not reasonable and accurate enough.

[0113] The method for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention analyzes and compares the operating principles of SVG under industrial frequency and low frequency, compares the inductance parameters and reactive current output capacity under industrial frequency scenario, and combines the short-circuit ratio of the SVG steady-state operation boundary under industrial frequency scenario, thereby calculating the low SVG steady-state operation boundary when the low-frequency SVG has the same reactive current output capacity as the industrial frequency scenario, thereby providing a steady-state operation basis for the low-frequency SVG.

[0114] The method for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention determines a first target voltage per unit value emitted by SVG at power frequency; determines the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that can enable SVG to normally emit rated current according to the current type emitted by SVG, the external equivalent voltage of SVG and the first target voltage per unit value; obtains the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determines the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value as boundary parameters of SVG steady-state operation. By taking the impedance ratio of SVG at low frequency as the main influencing factor affecting the steady-state operation of SVG and automatically determining quantifiable boundary parameters, the steady-state operation of SVG can be ensured.

[0115] Further, the determining of the first target voltage per unit value emitted by the SVG at the power frequency includes:

[0116] According to the voltage value intervals corresponding to the current types, the first target voltage per unit values ​​corresponding to the current types are determined. The above description can be referred to and will not be repeated.

[0117] Further, the current type includes inductive current; accordingly, determining the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that enables the SVG to normally emit a rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value includes:

[0118] If it is determined that the current type is the inductive current, the difference between the external equivalent voltage and the first target voltage per unit value is calculated to obtain a first voltage difference; the above embodiment can be referred to for description and will not be repeated here.

[0119] The ratio between the first voltage difference and the first per-unit value of the inductive reactance of the SVG at the power frequency is calculated to obtain a first current ratio, and the inverse of the first current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system. The above embodiments can be referred to for explanation and will not be repeated here.

[0120] Further, the current type includes capacitive current; accordingly, determining the system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value includes:

[0121] If it is determined that the current type is the capacitive current, the difference between the first target voltage per unit value and the external equivalent voltage is calculated to obtain a second voltage difference; the above embodiment can be referred to for description and will not be repeated here.

[0122] The ratio between the second voltage difference and the first per-unit capacitive reactance value of SVG at the power frequency is calculated to obtain a second current ratio, and the inverse of the second current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system. The above-mentioned embodiments can be referred to for explanation and will not be described in detail.

[0123] Further, the step of obtaining the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value comprises:

[0124] Substituting the first target voltage per unit value, the power frequency value and the low frequency value into the following expression, a first expression to be solved is obtained:

[0125]

[0126] Wherein, K is the impedance ratio, is the first target voltage per unit value, is the second target voltage per unit value, ω1 is the power frequency value, ω2 is the low frequency value, and sqrt represents the square root; the above embodiment can be referred to for description and will not be repeated here.

[0127] The denominator of the first expression to be solved is greater than zero as the first constraint condition, and the target voltage value range of the second target voltage per unit value is obtained. The above description can be referred to and will not be repeated here.

[0128] Furthermore, the method for determining boundary parameters of SVG steady-state operation also includes:

[0129] Obtain an impedance ratio value, substitute the impedance ratio value, the first target voltage per unit value, the power frequency value and the low-frequency frequency value into the expression to obtain a second expression to be solved; refer to the above embodiment for description and no further details will be given.

[0130] The second constraint condition is that the equation of the second expression to be solved is satisfied, and the target voltage value of the second target voltage per unit value is obtained. The above description can be referred to, and no further details are given.

[0131] Further, the low frequency value is 20 Hz or 50 / 3 Hz. Please refer to the above embodiment for description, which will not be repeated here.

[0132] Figure 3 FIG. 1 is a schematic diagram of a structure of a device for determining boundary parameters of SVG steady-state operation provided by an embodiment of the present invention. Figure 3 As shown, the boundary parameter determination device for SVG steady-state operation provided by the embodiment of the present invention includes a first determination unit 301, a second determination unit 302 and a third determination unit 303, wherein:

[0133] The first determination unit 301 is used to determine the first target voltage per unit value emitted by the SVG at the power frequency; the second determination unit 302 is used to determine the SVG electromagnetic transient simulation scenario system short-circuit ratio that can enable the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value; the third determination unit 303 is used to obtain the second target voltage per unit value according to the expression of the impedance ratio of the SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determine the SVG electromagnetic transient simulation scenario system short-circuit ratio and the second target voltage per unit value as boundary parameters for the steady-state operation of the SVG.

[0134] Specifically, the first determination unit 301 in the device is used to determine the first target voltage per unit value emitted by the SVG at the industrial frequency; the second determination unit 302 is used to determine the SVG electromagnetic transient simulation scenario system short-circuit ratio that can enable the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value; the third determination unit 303 is used to obtain the second target voltage per unit value according to the expression of the impedance ratio of the SVG at low frequency, the first target voltage per unit value, the industrial frequency value and the low frequency value, and determine the SVG electromagnetic transient simulation scenario system short-circuit ratio and the second target voltage per unit value as boundary parameters for the steady-state operation of the SVG.

[0135] The boundary parameter determination device for SVG steady-state operation provided by an embodiment of the present invention determines a first target voltage per unit value emitted by SVG at power frequency; determines a system short-circuit ratio of an SVG electromagnetic transient simulation scenario that enables SVG to normally emit a rated current according to the type of current emitted by SVG, the external equivalent voltage of SVG and the first target voltage per unit value; obtains a second target voltage per unit value according to an expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determines the system short-circuit ratio of the SVG electromagnetic transient simulation scenario and the second target voltage per unit value as boundary parameters for SVG steady-state operation. By taking the impedance ratio of SVG at low frequency as the main influencing factor affecting the steady-state operation of SVG and automatically determining quantifiable boundary parameters, the steady-state operation of SVG can be ensured.

[0136] The embodiment of the present invention provides an embodiment of a boundary parameter determination device for SVG steady-state operation, which can be specifically used to execute the processing flow of the above-mentioned method embodiments. Its functions are not repeated here, and reference can be made to the detailed description of the above-mentioned method embodiments.

[0137] Figure 4 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present invention, such as Figure 4 As shown, the electronic device includes: a processor (processor) 401, a memory (memory) 402 and a bus 403;

[0138] The processor 401 and the memory 402 communicate with each other via a bus 403;

[0139] The processor 401 is used to call the program instructions in the memory 402 to execute the methods provided by the above method embodiments, for example, including:

[0140] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0141] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0142] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0143] This embodiment discloses a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions. When the program instructions are executed by a computer, the computer can perform the methods provided by the above method embodiments, for example, including:

[0144] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0145] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0146] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0147] This embodiment provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, wherein the computer program enables the computer to execute the methods provided by the above method embodiments, for example, including:

[0148] Determine the first target voltage per unit value emitted by the SVG at the power frequency;

[0149] Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current;

[0150] According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

[0151] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0152] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0153] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0154] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0155] In the description of this specification, the description with reference to the terms "one embodiment", "a specific embodiment", "some embodiments", "for example", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0156] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for determining boundary parameters of SVG steady-state operation, characterized in that: include: Determine the first target voltage per unit value emitted by the SVG at the power frequency; Determining, according to the current type emitted by the SVG, the external equivalent voltage of the SVG and the first target voltage per unit value, a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current; According to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, the second target voltage per unit value is obtained, and the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value are determined as boundary parameters for the steady-state operation of SVG.

2. The method for determining boundary parameters of SVG steady-state operation according to claim 1, characterized in that: The determining of a first target voltage per unit value emitted by the SVG at the power frequency comprises: According to the voltage value ranges corresponding to the current types, first target voltage per unit values ​​corresponding to the current types are determined.

3. The method for determining boundary parameters of SVG steady-state operation according to claim 2, characterized in that: The current type includes inductive current; accordingly, determining the short-circuit ratio of the SVG electromagnetic transient simulation scenario system that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value, includes: If it is determined that the current type is the inductive current, calculating the difference between the external equivalent voltage and the first target voltage per unit value to obtain a first voltage difference; The ratio of the first voltage difference to the first per-unit value of the inductive reactance of the SVG at the power frequency is calculated to obtain a first current ratio, and the reciprocal of the first current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

4. The method for determining boundary parameters of SVG steady-state operation according to claim 2, characterized in that: The current type includes capacitive current; accordingly, determining the system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit the rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value, includes: If it is determined that the current type is the capacitive current, calculating the difference between the first target voltage per unit value and the external equivalent voltage to obtain a second voltage difference; The ratio of the second voltage difference to the first per-unit value of the capacitive reactance of the SVG at the power frequency is calculated to obtain a second current ratio, and the reciprocal of the second current ratio is determined as the short-circuit ratio of the SVG electromagnetic transient simulation scenario system.

5. The method for determining boundary parameters of SVG steady-state operation according to claim 1, characterized in that: The step of obtaining the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value comprises: Substituting the first target voltage per unit value, the power frequency value and the low frequency value into the following expression, a first expression to be solved is obtained: Wherein, K is the impedance ratio, is the first target voltage per unit value, is the second target voltage per unit value, ω1 is the power frequency value, ω2 is the low frequency value, and sqrt represents square root; Taking the denominator of the first expression to be solved being greater than zero as a first constraint condition, a target voltage numerical value range of the second target voltage per unit value is obtained.

6. The method for determining boundary parameters of SVG steady-state operation according to claim 5, characterized in that: The method for determining boundary parameters of SVG steady-state operation also includes: Obtain an impedance ratio value, substitute the impedance ratio value, the first target voltage per unit value, the power frequency value and the low frequency value into the expression to obtain a second expression to be solved; The equality of the second expression to be solved is established as a second constraint condition to obtain a target voltage value of the second target voltage per unit value.

7. The method for determining boundary parameters of SVG steady-state operation according to claim 5, characterized in that: The low frequency value is 20 Hz or 50 / 3 Hz.

8. A device for determining boundary parameters of SVG steady-state operation, characterized in that: include: A first determining unit, used to determine a first target voltage per unit value emitted by the SVG at an industrial frequency; A second determination unit is used to determine a system short-circuit ratio of the SVG electromagnetic transient simulation scenario that enables the SVG to normally emit a rated current according to the current type emitted by the SVG, the external equivalent voltage of the SVG, and the first target voltage per unit value; The third determination unit is used to obtain the second target voltage per unit value according to the expression of the impedance ratio of SVG at low frequency, the first target voltage per unit value, the power frequency value and the low frequency value, and determine the short-circuit ratio of the SVG electromagnetic transient simulation scenario system and the second target voltage per unit value as boundary parameters of the steady-state operation of SVG.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, 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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