Device, System and Method for Reactive Voltage Control in Multiple Substations

Abstract

A device, system and method for reactive voltage control of multiple substations are provided. The system includes: a master station device configured to receive a dispatching instruction from the power grid, generate a control instruction for a slave station device at a predetermined instruction control period based on the dispatching instruction, and send the generated control instruction to the slave station device; and a slave station device configured to receive the control instruction from the master station device and collect electrical quantity information at the grid connection point of the slave station, convert the received control instruction into a reactive power control target value based on the collected electrical quantity information at the grid connection point of the slave station, determine a reactive power control instruction for each controlled reactive power source according to the reactive power control target value, and send the determined reactive power control instruction to each controlled reactive power source.

Description

Technical Field

[0001] The present invention relates to the field of power control, and more particularly, to a device, a system and a method for reactive voltage control of multiple power stations. Background Art

[0002] New energy power generation often has the characteristics of being far from the load center, long-distance transmission, and centralized grid connection. With the continuous increase in the proportion of new energy and the continuous increase in the single-unit capacity, the installed capacity of power stations has also reached new highs. In recent years, the construction of large bases has gradually spread, and the planning and construction of new energy power stations have become more forward-looking. Especially with the investment in UHV DC transmission, large-scale centralized grid-connected new energy power generation is no longer a problem at the transmission level, and it has paved the way for the centralized grid-connected power generation of large base projects.

[0003] However, due to the characteristics of new energy power generation itself, large scale and concentrated power stations, this has brought great challenges to the overall grid connection friendliness. The coordinated control of multi-station centralized grid connection has become extremely important, and has also become the focus and difficulty, especially the reactive voltage control is more prominent. The traditional main station algorithm of new energy reactive voltage AVC (Automatic Voltage Control) based on power flow control often has limitations in use in centralized grid connection projects that require fast response and unified coordinated control due to the long operation control cycle. Therefore, how to effectively carry out unified coordinated control of the reactive voltage control of a multi-station centralized access system and ensure the control accuracy and speed has become an important research topic.

[0004] On the other hand, the automatic voltage control system can be basically divided into two major categories in terms of control mode: the control mode based on "optimal power flow" and the control mode based on hierarchical partitioning. The basic method of the control mode based on hierarchical partitioning is to divide voltage control into three levels: primary voltage control (PVC), secondary voltage control (SVC), and tertiary voltage control (TVC). However, whether it is the control mode based on hierarchical partitioning or the control mode of optimal power flow, in a multi-station centralized access system such as a large wind power base ( Figure 1An example topology diagram of such a centralized multi-station access system is shown. The centralized multi-station access system (also referred to as a multi-station centralized access system in the present invention) may include a collection station (the grid-connected station of the multi-station centralized access system) and one or more stations accessing the collection station. There are limitations in the reactive power voltage control of the multi-stations on the access point side of the station. The control method using optimal power flow has better economy when used in a larger system. However, for such a multi-station centralized access system, especially a new energy access system, more consideration is given to the operational safety and stability and the operational stability of the power generation units. Due to the distributed zoning of the new energy power generation units, for the optimal power flow control method that mainly considers economy, the power generation units often shut down due to reactive power output problems during the control process, causing economic losses to the stations. The hierarchical and zonal control mode is often divided into three layers of control: network dispatching, provincial dispatching, and station control. The collection station at the first-level control (i.e., the grid-connected station of the multi-station access system) is already in the first layer of the above three-layer zoning. However, there are still multiple stations downstream of the collection station that need to perform reactive power voltage control. Obviously, if the dispatching still directly controls each new energy station one by one at this time, the control effect cannot be achieved. Therefore, there is an urgent need for an effective control method for unified coordinated control of the multi-station access system, which not only meets the dispatching voltage control requirements of the collection station as the first-level voltage control but also ensures the stable operation of the power generation units of each station, thereby achieving the dual goals of safety and economy. Summary of the Invention

[0005] In order to at least solve the above problems in the prior art, the present application provides a device, a system, and a method for reactive power voltage control of multi-stations.

[0006] According to an aspect of the present invention, a master station device for reactive power voltage control of multi-stations is provided. The master station device includes: a master station receiving unit configured to receive a dispatching instruction from the power grid; a master station processing unit configured to generate a control instruction for a slave station device based on the dispatching instruction at a predetermined instruction control period; and a master station sending unit configured to send the generated control instruction to the slave station device. The master station processing unit can generate a control instruction in each predetermined instruction control period through the following operations: collect electrical quantity information at the grid connection point of the master station, where the electrical quantity information includes at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; determine a reactive power control target value based on the received dispatching instruction and at least one of the collected electrical quantity information; determine a control adjustment amount based on the reactive power control target value; and determine a control instruction for each slave station device based on the control adjustment amount.

[0007] When the control mode for multi-substation reactive power and voltage control is the reactive power control mode, the dispatching instruction may be a reactive power control instruction; when the control mode for multi-substation reactive power and voltage control is the power factor control mode, the dispatching instruction may be a power factor control instruction; and when the control mode for multi-substation reactive power and voltage control is the voltage control mode, the dispatching instruction may be a voltage control instruction.

[0008] The master station processing unit may be configured to determine the control adjustment amount through the following operations: calculating the deviation between the determined reactive power control target value and the reactive power measurement value at the grid connection point of the master station to obtain a reactive power deviation value; converting the reactive power deviation value into a voltage deviation value, and performing PI control on the voltage deviation value to obtain the control adjustment amount.

[0009] The master station processing unit may be configured to determine the control instruction for each substation device based on the voltage feedforward value and the control adjustment amount. Wherein, when the control mode for multi-substation reactive power and voltage control is the voltage control mode, the voltage feedforward value is indicated by the voltage control instruction; when the control mode for multi-substation reactive power and voltage control is the reactive power control mode or the power factor control mode, the voltage feedforward value is a fixed voltage value.

[0010] According to another aspect of the present invention, a substation device for multi-substation reactive power and voltage control is provided. The substation device includes: a substation receiving unit configured to receive a control instruction from the master station device; a substation processing unit configured to collect electrical quantity information at the grid connection point of the substation, convert the received control instruction into a reactive power control target value based on the collected electrical quantity information, and determine the reactive power control instruction for each controlled reactive power source according to the reactive power control target value. The electrical quantity information includes at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; and a substation sending unit configured to send the determined reactive power control instruction to each controlled reactive power source.

[0011] The substation processing unit may be configured to determine the reactive power control instruction for each controlled reactive power source through the following operations: obtaining a reactive power distribution coefficient based on the reactive power control target value; obtaining the reactive power control instruction for each controlled reactive power source based on the reactive power distribution coefficient.

[0012] According to another aspect of the present invention, a system for multi-substation reactive power and voltage control is provided. The system includes the master station device and the substation device as described above.

[0013] According to another aspect of the present invention, there is provided a method for multi-station reactive voltage control executed by a master station device, the method comprising: receiving a scheduling instruction from the power grid; generating a control instruction for a slave station device at a predetermined instruction control period based on the scheduling instruction; and sending the generated control instruction to the slave station device, wherein the control instruction for the slave station device is generated in each predetermined instruction control period by the following operations: collecting electrical quantity information at the grid connection point of the master station, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; determining a reactive power control target value based on at least one of the received scheduling instruction and the collected electrical quantity information; determining a control adjustment amount based on the reactive power control target value; and determining a control instruction for each slave station device based on the control adjustment amount.

[0014] When the control mode for multi-station reactive voltage control is a reactive power control mode, the scheduling instruction may be a reactive power control instruction; when the control mode for multi-station reactive voltage control is a power factor control mode, the scheduling instruction may be a power factor control instruction; and when the control mode for multi-station reactive voltage control is a voltage control mode, the scheduling instruction may be a voltage control instruction.

[0015] The step of determining the control adjustment amount may include: calculating a deviation between the determined reactive power control target value and the reactive power measurement value at the grid connection point of the master station to obtain a reactive power deviation value; converting the reactive power deviation value into a voltage deviation value, and performing PI control on the voltage deviation value to obtain the control adjustment amount.

[0016] The step of determining a control instruction for each slave station device based on the control adjustment amount may include: determining a control instruction for each slave station device based on a voltage feedforward value and the control adjustment amount, wherein when the control mode for multi-station reactive voltage control is a voltage control mode, the voltage feedforward value is indicated by the voltage control instruction, and when the control mode for multi-station reactive voltage control is a reactive power control mode or a power factor control mode, the voltage feedforward value is a fixed voltage value.

[0017] According to another aspect of the present invention, there is provided a method for multi-station reactive voltage control executed by a slave station device, the method comprising: receiving a control instruction from the master station device; collecting electrical quantity information at the grid connection point of the slave station, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; converting the received control instruction into a reactive power control target value based on the collected electrical quantity information, and determining a reactive power control instruction for each controlled reactive power source according to the reactive power control target value; and sending the determined reactive power control instruction to each controlled reactive power source.

[0018] The steps for determining the reactive power control instruction for the controlled reactive power sources may include: obtaining a reactive power distribution coefficient based on the reactive power control target value; and obtaining the reactive power control instruction for each controlled reactive power source based on the reactive power distribution coefficient.

[0019] According to another aspect of the present invention, there is provided a computer-readable storage medium, characterized in that computer program instructions are stored on the computer-readable storage medium, and when the computer program instructions are executed by a processor, the foregoing various methods are implemented.

[0020] According to another aspect of the present invention, there is provided a computer device, including a readable medium storing computer program instructions, characterized in that the computer program instructions include instructions for executing the various methods as described above.

[0021] Beneficial effects

[0022] By applying the multi-station reactive power and voltage control method according to the exemplary embodiments of the present invention, it is possible to perform unified coordinated control on the master station (i.e., the aggregation station) and the slave stations (i.e., the stations) of the multi-station centralized access system, achieve secondary voltage control of the multi-station centralized access system, enable the slave stations to accept unified synchronous control by the master station, and make the slave stations coordinated with each other. Thus, the reactive power control problem of the multi-station centralized access system can be solved. It can not only meet the dispatching voltage control requirements of the aggregation station as the first-level voltage control, but also quickly and accurately control each station and ensure the stable operation of the power generation units of each station, achieving the dual goals of safety and economy. Description of the drawings

[0023] From the following detailed description of the embodiments of the present invention in conjunction with the drawings, these and / or other aspects and advantages of the present invention will become clearer and easier to understand, where:

[0024] Figure 1 is an exemplary topology diagram showing a centralized multi-station access system;

[0025] Figure 2 is a block diagram showing a system for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention;

[0026] Figure 3 is a block diagram showing a master station device for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention;

[0027] Figure 4 is an exemplary control logic diagram showing the master station device according to an exemplary embodiment of the present invention;

[0028] Figure 5 is a flowchart showing a method at the master station device for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention;

[0029] Figure 6 is a block diagram showing a substation device for multi-station reactive voltage control according to an exemplary embodiment of the present invention;

[0030] Figure 7 is an example control logic diagram showing a substation device according to an exemplary embodiment of the present invention;

[0031] Figure 8 is a flowchart showing a method at a substation device for multi-station reactive voltage control according to an exemplary embodiment of the present invention.

[0032] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, and throughout the drawings, the same or similar elements will be denoted by the same or similar reference numerals. Detailed Description of the Invention

[0033] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the exemplary embodiments of the present invention defined by the claims and their equivalents. The description includes various specific details to facilitate understanding, but these details are considered to be merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, descriptions of known functions and configurations may be omitted for clarity and conciseness.

[0034] Figure 2 is a block diagram showing a system 200 for multi-station reactive voltage control according to an exemplary embodiment of the present invention.

[0035] Referring to Figure 2 , the system 200 for multi-station reactive voltage control according to an exemplary embodiment of the present invention may be composed of a master station device 210 and a substation device 220. The master station device 210 may be located in a collecting station serving as the master station (hereinafter, also simply referred to as the master station), and the substation device 220 may be located in each station serving as a substation (hereinafter, also simply referred to as the substation). Communication may be performed between the master station and the substation via Ethernet. Although Figure 2 shows one substation device 220, it should be understood that this is merely an example. When the master station is connected to multiple substations, each substation may have its own substation device 220 to receive control instructions from the master station device 210 located at the master station.

[0036] The master station device 210 may receive a dispatching instruction from the power grid, generate a control instruction for the substation device at a predetermined instruction control period based on the dispatching instruction, and send the generated control instruction to the substation device 220.

[0037] After receiving the control instruction from the master station device 210, the slave station device 220 can determine the reactive power control target value based on the received control instruction, determine the reactive power control instructions for each controlled reactive power source of the slave station according to the reactive power control target value, and send the determined reactive power control instructions to each controlled reactive power source. In an exemplary embodiment of the present invention, the controlled reactive power sources may include a power generation unit and a centralized reactive power compensation device. For example, as shown in Figure 1 the power generation unit and the centralized reactive power compensation device shown therein.

[0038] Hereinafter, the operations of the above-mentioned master station device 210 and slave station device 220 will be described in detail. Before starting the following description, for ease of understanding, first, the meanings of the various parameters involved in Figures 3 to 8 will be explained: Figure 4 and Figure 7 are explained:

[0039] S: Laplace transform operator.

[0040] T p : The first-order inertia time constant of the active power measurement value, which is used for the delay link in the present disclosure and plays a delay role.

[0041] T v : The first-order inertia time constant of the voltage measurement value, which is used for the delay link in the present disclosure and plays a delay role.

[0042] T Q : The first-order inertia time constant of the reactive power measurement value, which is used for the delay link in the present disclosure and plays a delay role.

[0043] T wt : The first-order inertia time constant of the voltage command value, which is used for the delay link in the present disclosure and plays a delay role.

[0044] T Qcmd : The first-order inertia time constant of reactive power source command distribution, which is used for the delay link in the present disclosure and plays a delay role.

[0045] K droop1 / K droop2 : Kdroop1 is the voltage-to-reactive power conversion droop control coefficient, and Kdroop2 is the reactive power-to-voltage conversion droop control coefficient. In the example of the present disclosure, the values of the two can be reciprocals of each other, but they can also be set in other ways.

[0046] (Q min,neg , Q max,pos ): Parameters for clipping. When the input value is greater than Q max,pos , the input value is set to Q max,pos and output. When the input value is less than Q min,neg , the input value is set to Q min,negAnd output, and in other cases, the input value is output as it is.

[0047] (V cmdmin , V cmdmax ): Parameters for clipping. When the input value is greater than V cmdmax , the input value is set to V cmdmax and output. When the input value is less than V cmdmin , the input value is set to V cmdmin and output, and in other cases, the input value is output as it is.

[0048] (Q min , Q max ): Parameters for clipping. When the input value is greater than Q max , the input value is set to Q max and output. When the input value is less than Q min , the input value is set to Q min and output, and in other cases, the input value is output as it is.

[0049] In addition, the parameters of Figure 4 and Figure 7 that are not explained above will be described in conjunction with specific embodiments hereinafter.

[0050] Figure 3 is a block diagram showing a master station device 210 for multi-station reactive voltage control according to an exemplary embodiment of the present invention. Figure 4 is an example control logic diagram showing the master station device 210 according to an exemplary embodiment of the present invention.

[0051] Referring to Figure 3 , a master station device 210 for multi-station reactive voltage control according to an exemplary embodiment of the present invention (hereinafter, simply referred to as the master station device 210) may include: a master station receiving unit 310, a master station processing unit 320, and a master station transmitting unit 330.

[0052] The master station receiving unit 310 may be configured to receive a scheduling instruction from the power grid (for example, from the provincial dispatching center). The scheduling instruction may vary according to the control mode for multi-station reactive voltage control. For example, when the control mode for multi-station reactive voltage control is the reactive power control mode, the scheduling instruction may be a reactive power control instruction (for example, Figure 4 the Q shown in ref ); when the control mode for multi-station reactive voltage control is the power factor control mode, the scheduling instruction may be a power factor control instruction (for example, Figure 4 the Pf shown in ref); when the control mode for multi-substation reactive voltage control is the voltage control mode, the dispatching instruction may be a voltage control instruction (for example, Figure 4 V shown in ref ).

[0053] After receiving the dispatching instruction, the master station processing unit 320 may generate a control instruction for the slave station device 220 based on the dispatching instruction at a predetermined instruction control period.

[0054] Specifically, in each predetermined instruction control period, the master station processing unit 320 may first collect the current electrical quantity information at the grid connection point of the master station (for example, Figure 1 the grid connection point of the collection station shown in Figure 4 ), such as the active power measurement value P shown in meas , the voltage measurement value V meas , and the reactive power measurement value Q meas at least one of them.

[0055] After that, the master station processing unit 320 may determine the reactive power control target value based on at least one of the received dispatching instruction and the collected electrical quantity information, determine the control adjustment amount based on the reactive power control target value, and determine the control instruction for each slave station device based on the control adjustment amount.

[0056] Specifically, when the control mode is the reactive power control mode, the master station processing unit 320 may directly determine the reactive power control target value according to the dispatching instruction. Only as an example, as shown in Figure 4 , the master station processing unit 320 may directly determine the reactive power control target value Q ref from the dispatching instruction Q target . In other control modes, the master station processing unit 320 may obtain the reactive power control target value according to the calculation between the dispatching instruction and the electrical quantity information value at the current grid connection point. Only as an example, as shown in Figure 4 , when the control mode is the power factor control mode, the master station processing unit 320 may calculate and obtain the reactive power control target value Q ref according to the mathematical relationship between the dispatching instruction Pf meas and the active power measurement value P target . When the control mode is the voltage control mode, the master station processing unit 320 may calculate the reactive power control target value Q ref according to the deviation V meas between the dispatching instruction V error and the voltage measurement value V target .

[0057] In an exemplary embodiment of the present invention, the master station processing unit 320 may compare the determined reactive power control target value with the reactive power measurement value at the grid connection point of the master station (for example, Figure 4Q shown in meas ) perform deviation calculation to obtain the reactive power deviation value. Only as an example, for instance, referring to Figure 4 , the master station processing unit 320 may first limit the determined reactive power control target value Q min,neg , Q max,pos ) and calculate the deviation between the limited reactive power control target value and the reactive power measurement value Q target . The result of the deviation calculation can be determined as the reactive power deviation value after being limited again through the parameters (Q meas , Q min,neg , Q max,pos ).

[0058] Then, the master station processing unit 320 may convert the reactive power deviation value into a voltage deviation value and perform PI (Proportional Integral Controller) control on the voltage deviation value to obtain a control adjustment amount. In an exemplary embodiment of the present invention, the master station processing unit 320 may inverse-transform the reactive power deviation value into a voltage deviation value by droop control as shown in Figure 4 , where the droop control system coefficient K droop2 of the droop control operation is calculated as shown in the following formula (1):

[0059] K droop2 = 1 / K droop1 = K factor / Q max (Formula 1)

[0060] Wherein, K factor is a voltage and reactive power transformation coefficient that can be preset in advance. Q max is the maximum reactive power capacity, with the unit of MVar. However, it should be understood that the method of converting the reactive power deviation value into a voltage deviation value is not limited to this, and various methods known to those skilled in the art can also be used to achieve this conversion.

[0061] In an exemplary embodiment of the present invention, the master station processing unit 320 may consider the voltage feedforward value, and thus determine the control instructions for each sub-station device based on the voltage feedforward value and the control adjustment amount (i.e., Figure 4 V shown in set,1 , ……, V set,N ). Only as an example, as shown in Figure 4 , the voltage feedforward value may be the input at the V ref terminal, and when the control mode for multi-station reactive power voltage control is the voltage control mode, this voltage feedforward value may be indicated by the received voltage control instruction V ref , while when the control mode is the reactive power control mode or the power factor control mode, this voltage feedforward value may be a fixed voltage value (i.e., setting V refThe input at the end is set to a fixed voltage). Here, as Figure 4 shown, the control instruction (e.g., Figure 4 shown in set,1 V set,N , ……, V cmdmin , V cmdmax ) can be a control instruction limited by parameters (V

[0062] In an exemplary embodiment of the present invention, the control instruction between the master station and the slave station can be a voltage control instruction. However, it should be understood that the present application is not limited thereto, and other forms of control instructions (e.g., reactive power control instruction, power factor control instruction, etc.) can also be used between the master station and the slave station, as long as the control instruction can reflect the required reactive power control target.

[0063] The master station sending unit 330 can send the above control instruction to the slave station device in each slave station.

[0064] It should be understood that although Figure 4 shows a control logic diagram of the master station device 210, this is only an example shown for ease of understanding, and the present application is not limited thereto. The control logic of the master station device 210 can include more or fewer components or operations, as long as the control objective of the present disclosure can be achieved.

[0065] Figure 5 is a flowchart showing a method at the master station device 210 for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention.

[0066] Referring to Figure 5 , in step S510, a dispatching instruction can be received from the power grid (e.g., provincial dispatching power grid) through the master station receiving unit 310 of the master station device 210. In an exemplary embodiment of the present invention, when the control mode for multi-station reactive power and voltage control is a reactive power control mode, the dispatching instruction can be a reactive power control instruction; when the control mode for multi-station reactive power and voltage control can be a power factor control mode, the dispatching instruction can be a power factor control instruction; and when the control mode for multi-station reactive power and voltage control is a voltage control mode, the dispatching instruction can be a voltage control instruction.

[0067] After that, in step S520, the master station processing unit 320 of the master station device 210 can generate a control instruction for the slave station device based on the dispatching instruction at a predetermined instruction control period.

[0068] Here, in each predetermined instruction control cycle, the master station processing unit 320 may collect the current electrical quantity information at the grid connection point of the master station, determine the reactive power control target value based on at least one of the received dispatching instruction and the collected electrical quantity information, determine the control adjustment amount based on the reactive power control target value, and determine the control instruction for each sub-station device based on the control adjustment amount. Here, the electrical quantity information may include at least one of: active power measurement value, voltage measurement value, and reactive power measurement value. The master station processing unit 320 may perform deviation calculation on the determined reactive power control target value and the reactive power measurement value at the grid connection point of the master station to obtain the reactive power deviation value, convert the reactive power deviation value into a voltage deviation value, and perform PI control on the voltage deviation value to obtain the control adjustment amount.

[0069] In addition, in step S520, the master station processing unit 320 may further consider the voltage feedforward value, and thus determine the control instruction for each sub-station device based on the voltage feedforward value and the control adjustment amount. Here, when the control mode for multi-station reactive power and voltage control is the voltage control mode, the voltage feedforward value may be indicated by the received voltage control instruction, and when the control mode for multi-station reactive power and voltage control is the reactive power control mode or the power factor control mode, the voltage feedforward value may be a fixed voltage value.

[0070] The above has been combined with Figure 3 and Figure 4 to describe in detail the various operations of the master station device 210, and therefore for the sake of brevity, it will not be elaborated here.

[0071] Figure 6 is a block diagram showing a sub-station device 220 for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention. Figure 7 is a control logic diagram showing the sub-station device 220 according to an exemplary embodiment of the present invention.

[0072] Referring to Figure 6 , a sub-station device 220 for multi-station reactive power and voltage control according to an exemplary embodiment of the present invention (hereinafter, simply referred to as the sub-station device 220) may include: a sub-station receiving unit 610, a sub-station processing unit 620, and a sub-station sending unit 630.

[0073] The sub-station receiving unit 610 may receive the control instruction from the master station device 210. Here, referring to Figure 4 as shown, when the control instruction sent by the master station device 210 is a voltage control instruction, the control instruction received from the master station device 210 may be used as the input terminal V of the sub-station device 220 refThe input is provided to the substation device 220. However, it should be understood that this application is not limited thereto. When the control instruction sent by the master station device 210 is a control instruction in other forms, the control instruction can be provided to the substation device 220 as the input of other input terminals of the substation device 220. For example, when the control instruction sent by the master station device 210 is a reactive power control instruction, the control instruction can be used as the input of input terminal Q of the substation device 220 ref The input is provided to the substation device 220.

[0074] After receiving the control instruction, the substation processing unit 620 can collect the electrical quantity information at the grid connection point of the substation. For example, Figure 7 the active power measurement value P shown meas and the voltage measurement value V meas and at least one of the reactive power measurement values (not shown in Figure 7 ).

[0075] Then, the substation processing unit 620 can convert the received control instruction into a reactive power control target value based on the collected electrical quantity information, and determine the reactive power control instruction for each controlled reactive power source according to the reactive power control target value. Here, the controlled reactive power sources can be each generating unit and centralized reactive power compensation equipment of the substation.

[0076] Specifically, similar to the master station device 210, when the control instruction is a reactive power control instruction, the substation processing unit 620 can directly determine the reactive power control target value according to the control instruction. Only as an example, as Figure 7 shown in, the substation processing unit 620 can directly determine the reactive power control target value Q from the control instruction Q ref target . In other cases, the substation processing unit 620 can obtain the reactive power control target value according to the calculation between the control instruction and the current electrical quantity information value. Only as an example, as Figure 7 shown in, when the control instruction is a power factor control instruction, the substation processing unit 620 can calculate the reactive power control target value Q according to the mathematical relationship between the control instruction Pf ref and the active power measurement value P meas . When the control instruction is a voltage control instruction, the reactive power control target value can be calculated according to the deviation V target between the control instruction V ref and the voltage measurement value V meas to calculate the reactive power control target value Q error target .

[0077] ​​In an exemplary embodiment of the present invention, the substation processing unit 620 may obtain a reactive power distribution coefficient based on the obtained reactive power control target value, and obtain a reactive power control instruction for each controlled reactive power source based on the reactive power distribution coefficient. Here, the reactive power distribution coefficient ScaleFactor may be calculated according to the following formula:

[0078] ScaleFactor = Q target / Q max (Equation 2)

[0079] Wherein, Q target is the reactive power control target value, with the unit of MVar. Q max is the maximum reactive power capacity of the substation, with the unit of MVar.

[0080] In an exemplary embodiment of the present invention, for example, referring to Figure 7 as shown, the reactive power control target value Q target obtained from the conversion of the control instruction can be provided for subsequent operations (such as calculating the reactive power distribution coefficient and determining the reactive power control instruction for each controlled reactive power source) after being limited by the parameters (Q min,neg , Q max,pos ).

[0081] In addition, in an exemplary embodiment of the present invention, for example, referring to Figure 7 as shown, the substation processing unit 620 can limit each obtained reactive power control instruction by the parameters (Q ming , Q ma ), and provide the limited reactive power control instruction (for example, Figure 7 QUnit1, ……, QUnitN in

[0082] ) to the substation sending unit 630.

[0083] The substation sending unit 630 can send the obtained reactive power control instruction to each controlled reactive power source. Figure 7 It should be understood that although Figure 7 shows a control logic diagram of the substation device 220, this is only an example shown for ease of understanding, and the present application is not limited thereto. The control logic of the substation device 220 may include more or fewer components or operations, as long as the control objective of the present disclosure can be achieved.

[0084] Figure 8 is a flowchart showing a method at the substation device 220 for multi-substation reactive power and voltage control according to an exemplary embodiment of the present invention.

[0085] Referring to Figure 8 , in step S810, the substation receiving unit 610 of the substation device 220 may receive a control instruction from the master station device 210.

[0086] After receiving the control instruction, at step S820, the substation processing unit 620 of the substation device 220 can collect the electrical quantity information at the grid connection point of the substation. Here, the electrical quantity information may include at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value.

[0087] At step S830, the substation processing unit 620 can convert the received control instruction into a reactive power control target value based on the collected electrical quantity information, and determine the reactive power control instructions for each controlled reactive power source according to the reactive power control target value. In an exemplary embodiment of the present invention, the substation processing unit 620 can obtain a reactive power distribution coefficient based on the reactive power control target value, and obtain the reactive power control instructions for each controlled reactive power source based on the reactive power distribution coefficient.

[0088] After that, at step S840, the substation sending unit 630 can send the determined reactive power control instructions to each controlled reactive power source of the substation.

[0089] The above has been described in detail in combination with Figure 6 and Figure 7 the various operations of the substation device 220, so for the sake of brevity, it will not be elaborated here.

[0090] In an exemplary embodiment of the present invention, as described above, since the master station device adopts PI control, the substation adopts open-loop control, which ensures the fast distribution of substation instructions and response speed.

[0091] In addition, in an exemplary embodiment of the present invention, the instruction control period for the master station device 210 located at the master station to generate control instructions for the substation device is in the millisecond level, and this period is much smaller than the time interval for the master station device 210 to receive scheduling instructions from the power grid. Therefore, after the master station device 210 receives a scheduling instruction from the power grid and before receiving the next scheduling instruction, it can repeatedly obtain various parameters and instructions for reactive power voltage control more quickly and accurately according to the scheduling instruction and real-time electrical quantity information, etc., at the instruction control period, thereby further realizing the fast and high-precision coordinated control of each substation, and achieving control effects such as good accuracy and response speed.

[0092] In addition, by applying the multi-station reactive voltage control method according to the exemplary embodiments of the present invention, unified and coordinated control can be performed on the master station (i.e., the aggregation station) and the slave stations (i.e., the stations) of the multi-station centralized access system, realizing secondary voltage control of the multi-station centralized access system, enabling the slave stations to accept unified synchronous control by the master station, and the slave stations to be coordinated with each other. Thus, the reactive power control problem of the multi-station centralized access system can be solved. It can not only meet the dispatching voltage control requirements of the aggregation station as the first-level voltage control, but also quickly and accurately control each station and ensure the stable operation of the power generation units of each station, achieving the dual goals of safety and economy.

[0093] Although the present invention has been specifically shown and described with reference to its exemplary embodiments, those skilled in the art should understand that various changes in form and details may be made thereto without departing from the spirit and scope of the invention defined by the claims.

Claims

1. A master station device for multi-station reactive voltage control, characterized in that, the master station device includes: A master station receiving unit configured to receive a dispatching instruction from the power grid; A master station processing unit configured to generate a control instruction for a slave station device at a predetermined instruction control period based on the dispatching instruction, the control instruction being a target voltage value; and A master station sending unit configured to send the generated control instruction to the slave station device, wherein, the master station processing unit generates a control instruction in each predetermined instruction control period through the following operations: Collect electrical quantity information at the grid connection point of the master station, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; Determine a reactive power control target value based on at least one of the received dispatching instruction and the collected electrical quantity information; Determine a control adjustment amount based on the reactive power control target value; Determine control instructions for each slave station device based on the control adjustment amount, wherein, the master station processing unit is configured to determine control instructions for each slave station device based on a voltage feedforward value and the control adjustment amount, and wherein, when the control mode for multi-station reactive voltage control is a voltage control mode, the voltage feedforward value is indicated by the dispatching instruction, and when the control mode for multi-station reactive voltage control is a reactive power control mode or a power factor control mode, the voltage feedforward value is a fixed voltage value.

2. The master station device according to claim 1, characterized in that, when the control mode for multi-station reactive voltage control is a reactive power control mode, the dispatching instruction is a reactive power control instruction; when the control mode for multi-station reactive voltage control is a power factor control mode, the dispatching instruction is a power factor control instruction; and when the control mode for multi-station reactive voltage control is a voltage control mode, the dispatching instruction is a voltage control instruction.

3. The master station device according to claim 1, characterized in that, the master station processing unit is configured to determine the control adjustment amount through the following operations: Perform a deviation calculation on the determined reactive power control target value and the reactive power measurement value at the grid connection point of the master station to obtain a reactive power deviation value; Convert the reactive power deviation value into a voltage deviation value, and perform PI control on the voltage deviation value to obtain the control adjustment amount.

4. A system for multi-station reactive voltage control, characterized in that, the system includes the master station device according to any one of claims 1-3 and a slave station device for multi-station reactive voltage control, the slave station device includes: A slave station receiving unit configured to receive a control instruction from the master station device; A slave station processing unit configured to collect electrical quantity information at the grid connection point of the slave station, convert the received control instruction into a reactive power control target value based on the collected electrical quantity information, and determine reactive power control instructions for each controlled reactive power source according to the reactive power control target value, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; and A slave station sending unit configured to send the determined reactive power control instructions to each controlled reactive power source.

5. The system for multi-station reactive power and voltage control according to claim 4, characterized in that, the sub-station processing unit is configured to determine reactive power control instructions for each controlled reactive power source through the following operations: obtain reactive power distribution coefficients based on the reactive power control target values; obtain reactive power control instructions for each controlled reactive power source based on the reactive power distribution coefficients.

6. A method for multi-station reactive power and voltage control executed by a master station device, the method comprising: receiving a scheduling instruction from the power grid; generating control instructions for the sub-station device at a predetermined instruction control period based on the scheduling instruction, the control instructions being target voltage values; and sending the generated control instructions to the sub-station device, wherein the control instructions for the sub-station device are generated in each predetermined instruction control period through the following operations: acquiring electrical quantity information at the grid connection point of the master station, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; determining reactive power control target values based on at least one of the received scheduling instruction and the acquired electrical quantity information; determining a control adjustment amount based on the reactive power control target values; determining control instructions for each sub-station device based on the control adjustment amount, wherein the control instructions for each sub-station device are determined based on a voltage feed-forward value and the control adjustment amount, and wherein when the control mode for multi-station reactive power and voltage control is a voltage control mode, the voltage feed-forward value is indicated by the scheduling instruction, and when the control mode for multi-station reactive power and voltage control is a reactive power control mode or a power factor control mode, the voltage feed-forward value is a fixed voltage value.

7. A method for multi-station reactive power and voltage control, characterized in that, the method includes the method for multi-station reactive power and voltage control executed by the master station device according to claim 6 and the method for multi-station reactive power and voltage control executed by the sub-station device, and the method for multi-station reactive power and voltage control executed by the sub-station device includes: receiving control instructions from the master station device; acquiring electrical quantity information at the grid connection point of the sub-station, the electrical quantity information including at least one of an active power measurement value, a voltage measurement value, and a reactive power measurement value; converting the received control instructions into reactive power control target values based on the acquired electrical quantity information, and determining reactive power control instructions for each controlled reactive power source according to the reactive power control target values; sending the determined reactive power control instructions to each controlled reactive power source.

8. A computer-readable storage medium, characterized in that, computer program instructions are stored on the computer-readable storage medium, and when the computer program instructions are executed by a processor, the method according to claim 6 or 7 is implemented.

9. A computer device, including a readable medium storing computer program instructions, characterized in that, the computer program instructions include instructions for executing the method according to claim 6 or 7.

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