A dynamic reactive power compensation device and a dynamic compensation method

Abstract

The present invention discloses a dynamic reactive power compensation device and a dynamic compensation method, the device includes: an initialization module, which initializes and sets a unit monitoring time period, a safe voltage interval, and a safe reactive power interval; a dynamic reactive power compensation module, which is connected to the power grid and is used to change the reactive power connected to the power grid; a power grid state monitoring module, which is connected to the power grid and is used to measure the voltage of the low-voltage bus and the reactive power exchanged between power grids according to the unit monitoring time period interval and send them to an AVC control module; and an AVC control module, which is used to obtain the voltage of the low-voltage bus and the reactive power exchanged between power grids obtained by the power grid state monitoring module and automatically control the dynamic reactive power compensation module according to its own control strategy. The present invention monitors the power grid state in real time, so that the dynamic reactive power compensation operates stably, reduces the uncertainty of power grid operation, maintains the voltage stability of the power system, and improves the safety of power grid operation.

Description

Technical Field

[0001] The present invention relates to the technical field of dynamic reactive power compensation, and more particularly to a dynamic reactive power compensation device and a dynamic compensation method. Background Art

[0002] With the rapid development of the national economy and the rapid increase in electricity load, voltage stability in load-intensive areas of the power grid is receiving increasing attention. Rapid and effective reactive power compensation is a key means of improving voltage stability. Compared to traditional reactive power compensation devices, dynamic reactive power compensation devices, based on power electronics technology, offer superior control speed and continuous adjustment, significantly improving system voltage stability. Consequently, dynamic reactive power compensation devices, such as static VAR compensators (SVCs) or static VAR generators (SVGs), are gaining increasing application in power grid operations.

[0003] An SVC (Static VAR Compensator) is a thyristor valve-controlled dynamic reactive power compensation device. By controlling the conduction angles of the thyristors, it modulates the value of the equivalent inductance connected in parallel to the system, thereby varying the reactive power input. With a millisecond-level response speed, dynamic reactive power compensation devices can quickly smooth voltage fluctuations and provide dynamic reactive power support in the event of major disturbances such as short circuits.

[0004] SVG (Static Var Generator), a static var generator, uses a power module for reactive power compensation. The power factor after compensation is generally above 0.98.

[0005] Dynamic reactive power compensation is applied in the power grid system. Due to speed regulation and phase change, the voltage of the power grid system will rise or fall instantaneously, which will affect the operation of the dynamic reactive power compensation device and cause overcurrent in the dynamic reactive power compensation device. In severe cases, the dynamic reactive power compensation device will be damaged, thereby affecting the reliability of the dynamic reactive power compensation device and further affecting the reactive power compensation function of the power grid system. Summary of the Invention

[0006] The purpose of the present invention is to provide a dynamic reactive power compensation device and a dynamic compensation method, which can realize stable operation of dynamic reactive power compensation by real-time monitoring of the power grid status, reduce the uncertainty of power grid operation, maintain the voltage stability of the power system, and improve the safety of power grid operation.

[0007] In order to achieve the above object, a dynamic reactive power compensation device is provided, comprising:

[0008] Initialization module, initialization setting unit monitoring time period, safe voltage range, safe reactive power range;

[0009] Dynamic reactive power compensation module, connected to the grid, used to change the reactive power connected to the grid;

[0010] The grid status monitoring module is connected to the grid and is used to measure the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and send them to the AVC control module;

[0011] The AVC control module is used to obtain the unit monitoring time period obtained by the grid status monitoring module to measure the voltage of the low-voltage bus and the reactive power exchanged between the grids and automatically control the dynamic reactive compensation module according to its own control strategy; the control strategy is to control the grid status monitoring module according to the dynamic reactive compensation determination method;

[0012] The AVC control module is connected to the initialization module, the dynamic reactive power compensation module and the power grid status monitoring module respectively.

[0013] Particularly, the dynamic reactive power compensation module adopts SVC or SVG.

[0014] In particular, the dynamic reactive power compensation determination method is to obtain a control instruction based on the voltage difference, reactive power difference and instruction determination method and send it to the dynamic reactive power compensation module so that the dynamic reactive power compensation module performs corresponding actions according to the control instruction; the control instruction includes a constant reactive power control instruction, an upper voltage control instruction, and a lower voltage control instruction;

[0015] In particular, the reactive power control instruction is used to put the dynamic reactive power compensation module in a constant reactive power state; the upper voltage control instruction is used to reduce the reactive power output of the dynamic reactive power compensation device, so that the dynamic reactive power compensation device absorbs reactive power as much as possible; the lower voltage control instruction increases the reactive power output of the dynamic reactive power compensation device, so that the dynamic reactive power compensation device emits reactive power as much as possible.

[0016] Particularly, the voltage difference is the difference between the front and rear voltages of the low-voltage bus within a unit monitoring time period.

[0017] Particularly, the reactive power difference is the absolute value of the reactive power exchanged between the power grids before and after a unit monitoring time period.

[0018] In particular, the instruction determination method includes the following steps:

[0019] S1 determines the voltage difference: If the voltage difference is in a safe voltage range, the control command is temporarily set to a constant reactive power control command; if the voltage difference exceeds the safe voltage range, the control command is temporarily set to an upper voltage control command; if the voltage difference is lower than the safe voltage range, the control command is temporarily set to determine the lower voltage control command;

[0020] S2 reactive power difference: If the control instruction is the voltage control instruction, execute step S201; if the control instruction is the voltage control instruction, execute step S202;

[0021] Step S201: If the reactive power difference is within or exceeds the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is less than the safe reactive power range, the control instruction is set to a constant reactive power control instruction;

[0022] Step S202: If the reactive power difference is lower than the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is in or exceeds the safe reactive power range, the control instruction is set to a constant reactive power control instruction.

[0023] A dynamic compensation method based on the above dynamic compensation device comprises the following steps:

[0024] Step 1: Initialize and set the unit monitoring time period, safe voltage range, and safe reactive power range through the initialization module;

[0025] Step 2: The grid status monitoring module measures the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and sends them to the AVC control module;

[0026] Step 3: The AVC control module obtains the unit monitoring time period obtained by the grid status monitoring module, measures the voltage of the low-voltage bus and the reactive power exchanged between the grids, and automatically controls the dynamic reactive compensation module according to its own control strategy; the control strategy is to control the grid status monitoring module according to the dynamic reactive compensation determination method;

[0027] Step 4: Start the loop from step 2.

[0028] Beneficial effects of the present invention:

[0029] The present invention, when the voltage of the power grid system may rise or fall instantaneously due to speed regulation and phase change, measures the voltage of the low-voltage bus and the reactive power exchanged between the power grids at intervals of a unit monitoring time period through a power grid state monitoring module and sends the measurements to an AVC control module; the AVC control module obtains the voltage of the low-voltage bus and the reactive power exchanged between the power grids obtained by the power grid state monitoring module and automatically controls the dynamic reactive compensation module according to its own control strategy; the control strategy is to control the power grid state monitoring module according to a dynamic reactive compensation determination method; the dynamic reactive compensation module is controlled by a constant reactive control instruction, an upper voltage control instruction, and a lower voltage control instruction; the reactive control instruction puts the dynamic reactive compensation module in a constant reactive state; the upper voltage control instruction reduces the reactive output of the dynamic reactive compensation device so that the dynamic reactive compensation device absorbs reactive power as much as possible; the lower voltage control instruction increases the reactive output of the dynamic reactive compensation device so that the dynamic reactive compensation device emits reactive power as much as possible. Therefore, the present invention can take into account the coordination of voltage and reactive power, so that both voltage and reactive power can operate stably, adapt to the occurrence of various emergencies in the power grid, maintain the voltage stability of the power system, and improve the safety of power grid operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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 description of the prior art. 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 paying any creative work.

[0031] Figure 1 is a structural block diagram of a dynamic reactive power compensation device according to an embodiment of the present invention;

[0032] Figure 2 Flowchart of a compensation method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] It should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Furthermore, terms such as "horizontal," "vertical," and "overhanging" do not necessarily imply that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0037] A dynamic reactive power compensation device and a dynamic compensation method, a dynamic reactive power compensation device such as Figure 1 shown.

[0038] Initialization module, initialization setting unit monitoring time period, safe voltage range, safe reactive power range;

[0039] The dynamic reactive power compensation module is connected to the power grid and is used to change the reactive power connected to the power grid; the dynamic reactive power compensation module adopts SVC or SVG.

[0040] The grid status monitoring module is connected to the grid and is used to measure the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and send them to the AVC control module;

[0041] The AVC control module is used to obtain the low-voltage bus voltage and inter-grid reactive power measured during each monitoring period by the grid status monitoring module and automatically control the dynamic reactive compensation module based on its own control strategy. The control strategy controls the grid status monitoring module based on a dynamic reactive compensation determination method. The dynamic reactive compensation determination method determines control instructions based on the voltage difference, reactive power difference, and an instruction determination method, and sends them to the dynamic reactive compensation module, causing it to perform corresponding actions based on the control instructions. Control instructions include a constant reactive power control instruction, an upper voltage control instruction, and a lower voltage control instruction. The reactive power control instruction maintains the dynamic reactive compensation module in a constant reactive power state. The upper voltage control instruction reduces the reactive output of the dynamic reactive compensation device, maximizing reactive power absorption; the lower voltage control instruction increases the reactive output of the dynamic reactive compensation device, maximizing reactive power generation. The voltage difference is the difference between the voltages of the low-voltage bus before and after each monitoring period. The reactive power difference is the absolute value of the inter-grid reactive power exchanged before and after each monitoring period.

[0042] The instruction determination method includes the following steps:

[0043] S1 determines the voltage difference: If the voltage difference is in a safe voltage range, the control command is temporarily set to a constant reactive power control command; if the voltage difference exceeds the safe voltage range, the control command is temporarily set to an upper voltage control command; if the voltage difference is lower than the safe voltage range, the control command is temporarily set to determine the lower voltage control command;

[0044] S2 reactive power difference: If the control instruction is the voltage control instruction, execute step S201; if the control instruction is the voltage control instruction, execute step S202;

[0045] Step S201: If the reactive power difference is within or exceeds the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is less than the safe reactive power range, the control instruction is set to a constant reactive power control instruction;

[0046] Step S202: If the reactive power difference is lower than the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is in or exceeds the safe reactive power range, the control instruction is set to a constant reactive power control instruction.

[0047] The AVC control module is connected to the initialization module, the dynamic reactive power compensation module and the grid status monitoring module respectively.

[0048] like Figure 2 As shown, a dynamic compensation method based on the above dynamic compensation device includes the following steps:

[0049] Step 1: Initialize and set the unit monitoring time period, safe voltage range, and safe reactive power range through the initialization module;

[0050] Step 2: The grid status monitoring module measures the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and sends them to the AVC control module;

[0051] In step three, the AVC control module obtains the low-voltage bus voltage and inter-grid reactive power measured during the unit monitoring time interval obtained by the grid status monitoring module and automatically controls the dynamic reactive compensation module according to its control strategy. The control strategy controls the grid status monitoring module based on a dynamic reactive compensation determination method. The dynamic reactive compensation determination method determines control instructions based on the voltage difference, reactive power difference, and an instruction determination method, and sends them to the dynamic reactive compensation module, causing it to perform corresponding actions based on the control instructions. The control instructions include a constant reactive power control instruction, an upper voltage control instruction, and a lower voltage control instruction. The reactive power control instruction is used to maintain the dynamic reactive compensation module in a constant reactive power state. The upper voltage control instruction reduces the reactive output of the dynamic reactive compensation device, maximizing reactive power absorption. The lower voltage control instruction increases the reactive output of the dynamic reactive compensation device, maximizing reactive power generation. The voltage difference is the difference between the voltages of the low-voltage bus before and after each monitoring time interval. The reactive power difference is the absolute value of the inter-grid reactive power exchanged before and after each monitoring time interval.

[0052] The instruction determination method includes the following steps:

[0053] S1 determines the voltage difference: If the voltage difference is in a safe voltage range, the control command is temporarily set to a constant reactive power control command; if the voltage difference exceeds the safe voltage range, the control command is temporarily set to an upper voltage control command; if the voltage difference is lower than the safe voltage range, the control command is temporarily set to determine the lower voltage control command;

[0054] S2 reactive power difference: If the control instruction is the voltage control instruction, execute step S201; if the control instruction is the voltage control instruction, execute step S202;

[0055] Step S201: If the reactive power difference is within or exceeds the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is less than the safe reactive power range, the control instruction is set to a constant reactive power control instruction;

[0056] Step S202: If the reactive power difference is lower than the safe reactive power range, the control instruction of step S1 is maintained; if the reactive power is in or exceeds the safe reactive power range, the control instruction is set to a constant reactive power control instruction.

[0057] Step 4: Start the loop from step 2.

[0058] Beneficial effects of the embodiments of the present invention:

[0059] In the embodiment of the present invention, when the voltage of the power grid system increases or decreases instantaneously due to speed regulation and phase change, the power grid state monitoring module measures the voltage of the low-voltage bus and the reactive power exchanged between the power grids according to the unit monitoring time interval and sends them to the AVC control module; the AVC control module obtains the voltage of the low-voltage bus and the reactive power exchanged between the power grids obtained by the power grid state monitoring module and automatically controls the dynamic reactive compensation module according to its own control strategy; the control strategy is to control the power grid state monitoring module according to the dynamic reactive compensation judgment method; the dynamic reactive compensation module is controlled by a constant reactive control instruction, an upper voltage control instruction, and a lower voltage control instruction, the reactive control instruction puts the dynamic reactive compensation module in a constant reactive state; the upper voltage control instruction reduces the reactive output of the dynamic reactive compensation device, and the dynamic reactive compensation device absorbs reactive power as much as possible; the lower voltage control instruction increases the reactive output of the dynamic reactive compensation device, and the dynamic reactive compensation device emits reactive power as much as possible. Therefore, the present invention can take into account the coordination of voltage and reactive power, so that both voltage and reactive power can operate stably, adapt to the occurrence of various emergencies in the power grid, maintain the voltage stability of the power system, and improve the safety of power grid operation.

[0060] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, the patent owner may make various changes or modifications within the scope of the appended claims. As long as they do not exceed the scope of protection described in the claims of the present invention, they should be within the scope of protection of the present invention.

Claims

1. A dynamic reactive power compensation device, characterized in that: include: Initialization module, initialization setting unit monitoring time period, safe voltage range, safe reactive power range; A dynamic reactive power compensation module is connected to the power grid and is used to change the reactive power connected to the power grid; The grid status monitoring module is connected to the grid and is used to measure the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and send them to the AVC control module; The AVC control module is used to obtain the voltage of the low-voltage bus and the reactive power exchanged between the power grids obtained by the power grid status monitoring module in the unit monitoring time interval and automatically control the dynamic reactive power compensation module according to its own control strategy; the control strategy is to control the power grid status monitoring module according to the dynamic reactive power compensation determination method; The AVC control module is respectively connected to the initialization module, the dynamic reactive power compensation module and the power grid status monitoring module; The dynamic reactive power compensation determination method is to obtain a control instruction based on the voltage difference, reactive power difference and instruction determination method and send it to the dynamic reactive power compensation module so that the dynamic reactive power compensation module performs corresponding actions according to the control instruction; the control instruction includes a constant reactive power control instruction, an upper voltage control instruction and a lower voltage control instruction; the reactive power control instruction is used to put the dynamic reactive power compensation module in a constant reactive power state; the upper voltage control instruction is used to reduce the reactive output of the dynamic reactive power compensation device, and the dynamic reactive power compensation device absorbs reactive power as much as possible; the lower voltage control instruction increases the reactive output of the dynamic reactive power compensation device, and the dynamic reactive power compensation device emits reactive power as much as possible; The instruction determination method comprises the following steps: S1. Determine the voltage difference: If the voltage difference is in the safe voltage range, the control command is temporarily set to the constant reactive power control command; if the voltage difference exceeds the safe voltage range, the control command is temporarily set to the upper voltage control command; if the voltage difference is lower than the safe voltage range, the control command is temporarily set to determine the lower voltage control command; S2 reactive power difference: If the control instruction is an upper voltage control instruction, execute step S201; if the control instruction is a lower voltage control instruction, execute step S202; Step S201: If the reactive power difference is in or exceeds the safe reactive power interval, the control instruction of step S1 is maintained; if the reactive power is less than the safe reactive power interval, the control instruction is set to a constant reactive power control instruction; Step S202: If the reactive power difference is lower than the safe reactive power interval, the control instruction of step S1 is maintained; if the reactive power is in or exceeds the safe reactive power interval, the control instruction is set to a constant reactive power control instruction.

2. A dynamic reactive power compensation device according to claim 1, characterized in that: The dynamic reactive power compensation module adopts SVC or SVG.

3. A dynamic reactive power compensation device according to claim 1, characterized in that: The voltage difference is the difference between the front and rear voltages of the low-voltage bus within a unit monitoring time period.

4. A dynamic reactive power compensation device according to claim 1, characterized in that: The reactive power difference is the absolute value of the reactive power exchanged between the power grids before and after the unit monitoring time interval.

5. A dynamic compensation method based on any one of the dynamic reactive power compensation devices according to claims 1 to 4, comprising the following steps: Step 1: Initialize and set the unit monitoring time period, safe voltage interval, and safe reactive power interval through the initialization module; Step 2: The grid status monitoring module measures the voltage of the low-voltage bus and the reactive power exchanged between grids according to the unit monitoring time interval and sends them to the AVC control module; Step 3: The AVC control module obtains the unit monitoring time period obtained by the power grid status monitoring module to measure the voltage of the low-voltage bus and the reactive power exchanged between power grids, and automatically controls the dynamic reactive power compensation module according to its own control strategy; the control strategy is to control the power grid status monitoring module according to the dynamic reactive power compensation determination method; Step 4: Start the cycle from step 2.

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