Unit control method and device, computer equipment, computer readable storage medium and computer program product

Abstract

The invention relates to a unit control method and device, computer equipment, a computer readable storage medium and a computer program product, and relates to the technical field of electric power. The method comprises the steps of obtaining a control instruction for a unit in a power plant, and determining a target working condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target working condition; based on the at least one working condition constraint of the target working condition, performing validity verification on the control instruction; under the condition that the validity verification of the control instruction under each working condition constraint is passed, performing security verification on the control instruction based on at least one security constraint of the power plant; and under the condition that the safety verification of the control instruction under each safety constraint is passed, the control instruction is issued to the unit, so that the unit enters a target working condition, and the output value of the unit under the target working condition reaches a target output value. The method can ensure the output stability of the power plant.

Description

Technical Field

[0001] The present application relates to the field of electric power technology, and in particular to a unit control method, device, computer equipment, computer-readable storage medium, and computer program product. Background Art

[0002] The unit is the core component of a power plant. Usually, the stable output of the power plant is ensured by controlling the unit to enter different operating conditions.

[0003] In the related art, control instructions for the units are usually determined and issued by technical personnel; however, it is difficult for technical personnel to grasp the current operating status of the power plant in real time, which results in the power plant's output stability decreasing after the units perform corresponding actions according to the control instructions, and the power plant's output stability cannot be guaranteed. Summary of the invention

[0004] Based on this, it is necessary to provide a unit control method, device, computer equipment, computer-readable storage medium and computer program product that can ensure the output stability of a power plant in response to the above-mentioned technical problem of being unable to ensure the output stability of a power plant.

[0005] In a first aspect, the present application provides a unit control method, comprising:

[0006] Obtaining a control instruction for a unit in a power plant, and determining a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition;

[0007] Based on at least one operating condition constraint of the target operating condition, performing validity verification on the control instruction;

[0008] When the validity check of the control instruction under each operating condition constraint is passed, the control instruction is subjected to safety check based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely;

[0009] When the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0010] In one of the embodiments, the operating condition constraint includes at least a head constraint;

[0011] The performing validity verification on the control instruction based on at least one operating condition constraint of the target operating condition includes:

[0012] Obtaining the rated water head of the unit;

[0013] Based on a pre-constructed mapping relationship between water head and output value, determining an output value interval corresponding to the target output value of the rated water head;

[0014] Based on the output value interval, performing validity verification on the target output value;

[0015] When the target output value falls within the output value interval, it is determined that the validity check of the control instruction under the water head constraint has passed.

[0016] In one embodiment, the operating condition constraint includes at least a power constraint, and the power constraint includes at least one of an active power constraint and a reactive power constraint;

[0017] The performing validity verification on the control instruction based on at least one operating condition constraint of the target operating condition includes:

[0018] Based on the target output value, determining the power information of the unit under the control instruction; the power information includes at least one of active information and reactive information;

[0019] Based on the power constraint, performing validity verification on the power information;

[0020] In a case where the power information satisfies the power constraint, it is determined that the validity check of the control instruction under the power constraint passes.

[0021] In one of the embodiments, the safety constraints include at least procedural constraints under the target operating conditions;

[0022] The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes:

[0023] Based on the target output value, determining the demand information of the unit corresponding to the regulation constraint under the control instruction;

[0024] Based on the regulation constraints, performing security verification on the demand information;

[0025] In a case where the requirement information satisfies the regulation constraint, it is determined that the safety check of the control instruction under the regulation constraint passes.

[0026] In one of the embodiments, the safety constraint includes at least a unit number constraint under the target operating condition, and the unit number constraint includes at least one of an accessible unit number constraint and an on-grid unit number constraint corresponding to the target operating condition;

[0027] The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes:

[0028] Based on the target output value, determine the number of units of the unit under the control instruction; the number of units information includes at least one of the number of units that can be entered and the number of units that have been connected to the network;

[0029] Based on the unit number constraint, performing safety verification on the unit number information;

[0030] In a case where the unit number information satisfies the unit number constraint, it is determined that the safety check of the control instruction under the unit number constraint has passed.

[0031] In one of the embodiments, the safety constraint includes at least a power change constraint under the target operating condition, and the power change constraint includes an active power change constraint and a reactive power change constraint;

[0032] The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes:

[0033] Based on the target output value, determining the power change information of the unit under the control instruction; the power change information includes at least one of the active power change rate and the reactive power change rate of the unit;

[0034] Based on the power change constraint, performing a security check on the power change information;

[0035] In a case where the power change information satisfies the power change constraint, it is determined that the safety check of the control instruction under the power change constraint has passed.

[0036] In a second aspect, the present application also provides a unit control device, comprising:

[0037] An instruction acquisition module is used to acquire a control instruction for a unit in a power plant and determine a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition;

[0038] A validity verification module, used to verify the validity of the control instruction based on at least one operating condition constraint of the target operating condition; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition;

[0039] A safety verification module, configured to, when the validity verification of the control instruction under each operating condition constraint is passed, perform safety verification on the control instruction based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely;

[0040] The instruction issuing module is used to issue the control instruction to the unit when the safety check of the control instruction under various safety constraints is passed, so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0041] In a third aspect, the present application further provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0042] Obtaining a control instruction for a unit in a power plant, and determining a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition;

[0043] Based on at least one operating condition constraint of the target operating condition, the control instruction is verified for validity; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition;

[0044] When the validity check of the control instruction under each operating condition constraint is passed, the control instruction is subjected to safety check based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely;

[0045] When the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0046] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0047] Obtaining a control instruction for a unit in a power plant, and determining a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition;

[0048] Based on at least one operating condition constraint of the target operating condition, the control instruction is verified for validity; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition;

[0049] When the validity check of the control instruction under each operating condition constraint is passed, the control instruction is subjected to safety check based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely;

[0050] When the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0051] In a fifth aspect, the present application further provides a computer program product, including a computer program, which implements the following steps when executed by a processor:

[0052] Obtaining a control instruction for a unit in a power plant, and determining a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition;

[0053] Based on at least one operating condition constraint of the target operating condition, the control instruction is verified for validity; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition;

[0054] When the validity check of the control instruction under each operating condition constraint is passed, the control instruction is subjected to safety check based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely;

[0055] When the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0056] The above-mentioned unit control method, device, computer equipment, computer-readable storage medium and computer program product first obtain a control instruction for the unit in the power plant and determine the target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition; then, based on at least one operating condition constraint of the target operating condition, the control instruction is verified for validity; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition; then, when the control instruction passes the validity check under each operating condition constraint, the control instruction is verified for safety based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met for the safe operation of the power plant; finally, when the control instruction passes the safety check under each safety constraint, the control instruction is issued to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value. In this way, based on at least one operating condition constraint of the target operating condition, the validity of the control instructions can be checked, and based on at least one safety constraint of the power plant, the safety of the control instructions can be checked. By issuing control instructions that have passed the validity check and the safety check to the unit, the unit can be controlled while ensuring effectiveness and safety, thereby ensuring the output stability of the power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments of the present application or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0058] Figure 1 A schematic flow chart of a unit control method in one embodiment;

[0059] Figure 2 is a flow chart of a step of performing validity verification on a control instruction based on at least one operating condition constraint of a target operating condition in one embodiment;

[0060] Figure 3 is a flow chart of a step of performing validity verification on a control instruction based on at least one operating condition constraint of a target operating condition in another embodiment;

[0061] Figure 4 A flowchart of a step of performing safety verification on a control instruction based on at least one safety constraint of a power plant in one embodiment;

[0062] Figure 5 is a flow chart of a step of performing safety verification on a control instruction based on at least one safety constraint of a power plant in another embodiment;

[0063] Figure 6 A flowchart of a step of performing safety verification on a control instruction based on at least one safety constraint of a power plant in yet another embodiment;

[0064] Figure 7 A schematic flow chart of a unit control method in another embodiment;

[0065] Figure 8 A schematic flow chart of a pumped storage unit control method in one embodiment;

[0066] Fig. 9 1 is a flow chart of the steps of performing validity verification on a set value under a target working condition corresponding to a control instruction in one embodiment;

[0067] Fig.10 1 is a flow chart of the steps of performing safety verification on a set value under a target working condition corresponding to a control instruction in one embodiment;

[0068] Fig.11 is a structural block diagram of a unit control device in one embodiment;

[0069] Fig.12 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0070] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0071] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0072] In one embodiment, Figure 1As shown, a unit control method is provided. This embodiment uses the method applied to a server as an example for illustration. It can be understood that the method can also be applied to a terminal, and can also be applied to a system including a server and a terminal, and is implemented through the interaction between the server and the terminal; wherein the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services; the terminal can be, but is not limited to, various personal computers, laptops, smart phones, tablet computers, etc. In this embodiment, the method includes the following steps S102 to S108:

[0073] Step S102, obtaining control instructions for the units in the power plant, and determining the target operating conditions corresponding to the control instructions.

[0074] There are multiple units in the power plant, and each unit is composed of multiple devices. In a specific application, the power plant is a pumped storage hydropower plant.

[0075] Among them, the control instruction is used to control the unit to enter the target operating condition from the current operating condition; further, the control instruction has a corresponding target output value under the target operating condition, and the control instruction is used to control the unit to enter the target operating condition and control the output value of the unit under the target operating condition to reach the target output value.

[0076] Among them, the operating conditions are used to characterize the status and function of the unit during operation. The operating conditions in this application include but are not limited to power generation conditions, pumping conditions, pump conditions, etc.

[0077] Among them, different operating conditions correspond to different output items, and the output value is the output value of the unit under the output item; for example, the output item of the power generation condition is the power generation power of the unit, and the output item of the pumping condition is the pumping power of the unit.

[0078] Specifically, when the technician needs to control the unit from the current operating condition to the target operating condition, and has expectations for the unit's output value under the target operating condition, a control instruction will be sent to the server; the server receives the control instruction sent by the technician and determines the target operating condition that the unit is expected to enter as expected by the control instruction.

[0079] Step S104: verifying the validity of the control instruction based on at least one operating condition constraint of the target operating condition.

[0080] Each operating condition has at least one corresponding operating condition constraint; the operating condition constraint of each operating condition is used to characterize the conditions that need to be met to enter the operating condition.

[0081] Specifically, the server obtains each operating condition constraint of the target operating condition, and performs validity verification on the control instruction based on each operating condition constraint. If the control instruction passes the validity verification under all operating condition constraints, it means that the control instruction can meet all conditions required to enter the target operating condition, and therefore the control instruction is valid. If the control instruction fails the validity verification under any operating condition constraint, it means that the control instruction cannot meet all conditions required to enter the target operating condition, and therefore the control instruction is invalid.

[0082] In actual applications, the server can traverse each operating condition constraint in turn, and verify the validity of the control instruction under the traversed operating condition constraint; if the verification result of the control instruction under the traversed operating condition constraint is failed, the validity verification of the subsequent operating condition constraint will no longer be performed, the control instruction is judged to be invalid, and the unit control process is exited.

[0083] In actual applications, the server can also verify the validity of the control instructions under various operating conditions at the same time; after the validity verification of all operating conditions is completed, the verification results under each operating condition are counted. If any one fails, the control instruction is judged to be invalid and the unit control process is exited.

[0084] Step S106: When the validity check of the control instruction under each operating condition constraint is passed, a safety check is performed on the control instruction based on at least one safety constraint of the power plant.

[0085] Among them, the safety constraints of the power plant are used to characterize the conditions that need to be met for the safe operation of the power plant.

[0086] Furthermore, the safety constraints of a power plant are different under different operating conditions.

[0087] Specifically, when the control instruction passes the validity check under all operating condition constraints, the server obtains the various safety constraints of the power plant and performs validity check on the control instruction based on the various safety constraints. If the control instruction passes the validity check under all safety constraints, it means that the control instruction can meet all conditions that need to be met for the safe operation of the power plant, and therefore the control instruction is safe. If the control instruction fails the safety check under any safety constraint, it means that the control instruction cannot meet all conditions that need to be met for the safe operation of the power plant, and therefore the control instruction is unsafe.

[0088] In actual applications, the server can traverse each safety constraint in turn, and perform a safety check on the control instruction under the traversed safety constraint; if the control instruction fails the check under the traversed safety constraint, the safety check of subsequent safety constraints will no longer be performed, the control instruction is judged to be unsafe, and the unit control process is exited.

[0089] In actual applications, the server can also perform safety checks on control instructions under various safety constraints at the same time; after the safety checks of all safety constraints are completed, the verification results under each safety constraint are counted. If any one fails, the control instruction is judged to be unsafe and the unit control process is exited.

[0090] Step S108, when the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit to make the unit enter the target operating condition and make the output value of the unit under the target operating condition reach the target output value.

[0091] Specifically, the server sends the control instruction to the unit when the safety check of the control instruction under all safety constraints has passed; the unit responds to the received control instruction and performs corresponding actions to enter the target working condition, and at the same time makes the output value of the unit under the target output item reach the target output value. The target output item is the output item corresponding to the target working condition, and also the output item to which the target output value belongs.

[0092] In the above-mentioned unit control method, first, the server obtains the control instruction for the unit in the power plant and determines the target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition; then, the server verifies the validity of the control instruction based on at least one operating condition constraint of the target operating condition; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition; then, when the control instruction passes the validity check under each operating condition constraint, the server verifies the safety of the control instruction based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met for the safe operation of the power plant; finally, when the control instruction passes the safety check under each safety constraint, the server sends the control instruction to the unit, so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value. In this way, the server can verify the validity of the control instructions based on at least one operating condition constraint of the target operating condition, and can verify the safety of the control instructions based on at least one safety constraint of the power plant. By issuing control instructions that have passed the validity check and the safety check to the unit, the unit can be controlled while ensuring effectiveness and safety, thereby ensuring the output stability of the power plant.

[0093] In an exemplary embodiment, the operating condition constraints include at least a water head constraint.

[0094] Among them, each unit has a corresponding rated head, which is determined when the unit is produced; the rated head determines the output capacity of the unit; in specific applications, the same rated head represents different output capacities under different output items (that is, the same rated head represents different output capacities under different operating conditions).

[0095] Among them, the head constraint is used to characterize the output capacity of the rated head under the target output item corresponding to the target operating condition when the unit enters the corresponding target operating condition, and whether it can make the output value of the unit under the target output item reach the target output value.

[0096] like Figure 2 As shown, the above step S104, based on at least one operating condition constraint of the target operating condition, performs validity verification on the control instruction, specifically including the following steps:

[0097] Step S202, obtaining the rated water head of the unit.

[0098] Step S204: determining an output value interval corresponding to a target output value for a rated water head based on a pre-constructed mapping relationship between water head and output value.

[0099] Step S206: Based on the output value interval, the target output value is verified for validity.

[0100] Step S208: When the target output value falls within the output value interval, it is determined that the validity check of the control instruction under the water head constraint has passed.

[0101] The server pre-builds a mapping relationship between different rated water heads and output values ​​under different output items, which may be a mapping function or a mapping relationship table.

[0102] Specifically, the server first obtains the rated water head of the unit, and based on the pre-constructed mapping relationship between the water head and the output value, converts the rated water head into a numerical range under the target output item corresponding to the target output value, and obtains the output value range, which represents the output capacity of the rated water head under the target output item corresponding to the target output value. Then, the server determines whether the target output value falls within the output value interval, so as to perform a validity check on the target output value based on the output value interval; if the target output value falls within the output value interval, it means that the output capacity of the rated head under the target output item corresponding to the target operating condition can make the output value of the unit under the target output item reach the target output value, so the server determines that the validity check of the control instruction under the head constraint has passed; if the target output value does not fall within the output value interval, it means that the output capacity of the rated head under the target output item corresponding to the target operating condition cannot make the output value of the unit under the target output item reach the target output value, that is, the target output value exceeds the output capacity of the rated head under the target output item, so the server determines that the validity check of the control instruction under the head constraint has failed, and the server exits the unit control process.

[0103] In this embodiment, the server can verify the output capacity of the rated head under the target output item corresponding to the control instruction through head constraints, and whether the output value of the unit under the target output item can reach the target output value required by the control instruction, thereby realizing the effectiveness verification of the control instruction under the head constraint, and ensuring that the target output value required by the issued control instruction does not exceed the output capacity corresponding to the head.

[0104] In an exemplary embodiment, the operating condition constraint includes at least a power constraint, and the power constraint includes at least one of an active power constraint and a reactive power constraint.

[0105] The power constraint of each operating condition is an active output constraint of an output item corresponding to the operating condition, specifically including at least one of an active output upper limit value and an active output lower limit value.

[0106] The reactive power constraint of each working condition is the reactive power absorption constraint and reactive power output constraint of the output item corresponding to the working condition, and specifically includes at least one of a reactive power absorption upper limit value and a reactive power output upper limit value.

[0107] like Figure 3 As shown, the above step S104, based on at least one operating condition constraint of the target operating condition, performs validity verification on the control instruction, specifically including the following steps:

[0108] Step S302: determining the power information of the unit under the control instruction based on the target output value.

[0109] Step S304: verify the validity of the power information based on the power constraint.

[0110] Step S306: When the power information satisfies the power constraint, it is determined that the validity check of the control instruction under the power constraint has passed.

[0111] The power information includes at least one of active information and reactive information; further, the active information specifically includes an active output value, and the reactive information specifically includes a reactive absorption value and a reactive output value.

[0112] Specifically, based on the target output value, the server calculates the power information of the computer group under the target output item corresponding to the control instruction (specifically at least one of the active output value, reactive absorption value and reactive output value); then, based on the type corresponding to the power information, the server selects the corresponding power constraint from the active output upper limit value, the active output lower limit value, the reactive absorption upper limit value and the reactive output upper limit value. Next, the server determines whether the power information meets the corresponding power constraint; if it does, it means that the power information of the unit is within the range required for the unit to enter the target operating condition, so the server determines that the validity check of the control instruction under the power constraint has passed; if it does not, it means that the power information of the unit is not within the range required for the unit to enter the target operating condition, so the server determines that the validity check of the control instruction under the power constraint has not passed, and the server exits the unit control process.

[0113] For example, based on the target output value, the server calculates the active output value, reactive absorption value and reactive output value of the computer group under the target output item corresponding to the control instruction; for the active output value, the server determines whether the active output value falls within the active output range composed of the active output upper limit value and the active output lower limit value of the unit under the target operating condition; for the reactive absorption value, the server determines whether the reactive absorption value is less than or equal to the reactive absorption upper limit value of the unit under the target operating condition; for the reactive output value, the server determines whether the reactive output value is less than or equal to the reactive output upper limit value of the unit under the target operating condition; if the active output value falls within the active output range, and the reactive absorption value is less than or equal to the reactive absorption upper limit value, and the reactive output value is less than or equal to the reactive output upper limit value, then the server determines that the validity check of the control instruction under the power constraint has passed; if any of the above three judgments is not met, then the server determines that the validity check of the control instruction under the corresponding power constraint has not passed, and the server exits the unit control process.

[0114] In this embodiment, the server can verify through power constraints whether the power of the target output value corresponding to the control instruction can meet the power constraint of the unit under the corresponding target output item, thereby realizing the effectiveness verification of the control instruction under the power constraint, and ensuring that the target output value required by the issued control instruction can meet the power constraint of the unit under the corresponding target output item.

[0115] In an exemplary embodiment, the safety constraints include at least regulatory constraints under target operating conditions.

[0116] Among them, regulatory constraints are used to characterize hydropower regulations that ensure safe operation of the power plant, for example, guide vane opening limits.

[0117] In specific applications, the procedural constraints of a power plant under different operating conditions may be different.

[0118] like Figure 4As shown, in the above step S106, based on at least one safety constraint of the power plant, the control instruction is checked for safety, which specifically includes the following steps:

[0119] Step S402: Based on the target output value, determine the demand information of the unit corresponding to the regulation constraint under the control instruction.

[0120] Step S404: Perform security verification on the demand information based on regulatory constraints.

[0121] Step S406: When the requirement information satisfies the regulation constraint, it is determined that the safety check of the control instruction under the regulation constraint has passed.

[0122] Among them, the demand information of the unit corresponding to the regulation constraint is used to characterize the demand information of the unit under the constraint object of the regulation constraint when the corresponding output value needs to reach the target output value; taking the regulation constraint as the guide vane opening limit as an example, the guide vane opening required by the unit when the corresponding output value needs to reach the target output value.

[0123] Specifically, based on the target output value, the server calculates the demand information of the constraint object corresponding to the regulation constraint when the output value of the computer group under the target output item corresponding to the control instruction needs to reach the corresponding target output value. Then, the server determines whether the demand information meets the corresponding regulation constraint; if it does, it means that the demand information of the unit is within the scope of the regulation constraint, so the server determines that the safety check of the control instruction under the regulation constraint has passed; if it does not meet, it means that the demand information of the unit is not within the scope of the regulation constraint, so the server determines that the safety check of the control instruction under the regulation constraint has not passed, and the server exits the unit control process.

[0124] For example, the server is based on the target output value, and when the output value of the computer group under the target output item corresponding to the control instruction reaches the corresponding target output value, the guide vane opening required is calculated, and the guide vane opening is compared with the guide vane opening limit required by the hydropower regulations; if the guide vane opening does not exceed the guide vane opening limit, the server determines that the safety check of the control instruction under the guide vane opening limit has passed; if the guide vane opening exceeds the guide vane opening limit, the server determines that the safety check of the control instruction under the guide vane opening limit has not passed, and the server exits the unit control process.

[0125] In this embodiment, the server can verify whether the control instructions meet the requirements of the hydropower regulations for ensuring the safe operation of the power plant through regulatory constraints, thereby realizing safety verification of the control instructions under regulatory constraints, and ensuring that the issued control instructions meet the requirements of the hydropower regulations for ensuring the safe operation of the power plant.

[0126] In an exemplary embodiment, the safety constraint includes at least a unit number constraint under a target operating condition, and the unit number constraint includes at least one of an accessible unit number constraint corresponding to the target operating condition and a networked unit number constraint.

[0127] In specific applications, the constraints on the number of units in a power plant under different operating conditions may be different.

[0128] The number of units that can enter each operating condition is constrained to be the maximum number of units that can enter the operating condition, which may be an upper limit or a lower limit.

[0129] The number of online units corresponding to each operating condition is constrained to the minimum number limit of units that have currently entered the operating condition, which may be an upper limit or a lower limit.

[0130] like Figure 5 As shown, in the above step S106, based on at least one safety constraint of the power plant, the control instruction is checked for safety, which specifically includes the following steps:

[0131] Step S502, based on the target output value, determine the number of units under the control instruction; the number of units information includes at least one of the number of accessible units and the number of units already on the network.

[0132] Step S504: Based on the unit number constraint, perform safety verification on the unit number information.

[0133] Step S506: When the unit number information satisfies the unit number constraint, it is determined whether the safety check of the control instruction under the unit number constraint has passed.

[0134] Among them, the unit number information includes at least one of the number of accessible units and the number of online units; further, the number of accessible units is the maximum number of accessible units, which is used to characterize the maximum number of units that can enter the target operating condition corresponding to the control instruction; the number of online units is the minimum number of online units, which is used to characterize the minimum number of units that have currently entered the target operating condition corresponding to the control instruction.

[0135] Specifically, based on the target output value, the server calculates at least one of the maximum number of units that can enter the target operating condition corresponding to the control instruction and the minimum number of units that have currently entered the target operating condition corresponding to the control instruction, and obtains the unit number information of the unit under the control instruction; then, based on the type of unit number information, the server selects the corresponding unit number constraint from the available unit number constraint and the networked unit number constraint. Next, the server determines whether the value of the unit number information meets the limit value corresponding to the unit number constraint; if it does, it means that the unit number information is within the range of the unit number constraint, so the server determines that the safety check of the control instruction under the unit number constraint has passed; if it does not, it means that the unit number information is not within the range of the unit number constraint, so the server determines that the safety check of the control instruction under the unit number constraint has not passed, and the server exits the unit control process.

[0136] For example, based on the target output value, the server calculates the maximum number of units that can enter the target operating condition corresponding to the control instruction and the minimum number of units that have currently entered the target operating condition corresponding to the control instruction, and obtains the maximum number of units that can enter and the minimum number of units already online; then, for the maximum number of units that can enter, the server determines whether the maximum number of units that can enter meets the maximum number limit of units that can enter the target operating condition, and for the minimum number of units already online, the server determines whether the minimum number of units already online meets the minimum number limit of units that have currently entered the operating condition; if both are satisfied, the server determines that the safety check of the control instruction under the constraint of the number of units has passed; if any of the above two judgments is not satisfied, the server determines that the safety check of the control instruction under the corresponding constraint of the number of units has not passed, and the server exits the unit control process.

[0137] In this embodiment, the server can verify whether the maximum number of accessible units and the minimum number of online units corresponding to the control instruction can meet the number of units required to ensure the safe operation of the power plant through the unit number constraint, thereby realizing the safety verification of the control instruction under the unit number constraint, and ensuring that the issued control instruction meets the unit number requirement to ensure the safe operation of the power plant.

[0138] In an exemplary embodiment, the safety constraint includes at least a power variation constraint under a target operating condition, and the power variation constraint includes an active power variation constraint and a reactive power variation constraint.

[0139] In specific applications, the power variation constraints of a power plant under different operating conditions may be different.

[0140] The power change constraint of each operating condition is the power change rate limit of the output item corresponding to the operating condition.

[0141] The active power change constraint is an active power change rate limit, which may specifically be an upper limit and / or a lower limit.

[0142] The reactive power change constraint is a reactive power change rate limit, which may specifically be an upper limit and / or a lower limit.

[0143] like Figure 6 As shown, in the above step S106, based on at least one safety constraint of the power plant, the control instruction is checked for safety, which specifically includes the following steps:

[0144] Step S602: determining the power change information of the unit under the control instruction based on the target output value.

[0145] Step S604: Perform security verification on the power change information based on the power change constraint.

[0146] Step S606: When the power change information satisfies the power change constraint, determine whether the safety check of the control instruction under the power change constraint has passed.

[0147] The power change information includes at least one of the active power change rate and the reactive power change rate of the unit.

[0148] Based on the target output value, the server calculates the power change information (specifically at least one of the active power change rate and the reactive power change rate) of the computer group under the target output item corresponding to the control instruction; then, based on the type corresponding to the power change information, the server selects the corresponding power change constraint from the active power change rate limit and the reactive power change rate limit. Next, the server determines whether the power change information satisfies the corresponding power change constraint; if it does, it means that the power change information of the unit is within the range of the power change constraint, so the server determines that the safety check of the control instruction under the power change constraint has passed; if it does not, it means that the power change information is not within the range of the power change constraint, so the server determines that the safety check of the control instruction under the power change constraint has not passed, and the server exits the unit control process.

[0149] For example, the server calculates the active power change rate and reactive power change rate of the computer group under the control instruction based on the target output value; then, for the active power change rate, the server determines whether the active power change rate meets the active power change rate limit, and for the reactive power change rate, the server determines whether the reactive power change rate meets the reactive power change rate limit; if both are satisfied, the server determines that the safety check of the control instruction under the power change constraint has passed; if any of the above two judgments is not satisfied, the server determines that the safety check of the control instruction under the corresponding power change constraint has not passed, and the server exits the unit control process.

[0150] In this embodiment, the server can verify whether the active power change rate and reactive power change rate of the control instruction can meet the power change rate for ensuring the safe operation of the power plant through power change constraints, thereby realizing the safety verification of the control instruction under the power change constraint, and ensuring that the issued control instruction meets the power change rate for ensuring the safe operation of the power plant.

[0151] In an exemplary embodiment, the safety constraints include at least a unit start interval constraint under a target operating condition.

[0152] In the above step S106, based on at least one safety constraint of the power plant, the control instruction is safety checked, specifically including the following contents: based on the target output value, determining the start interval time of the unit under the control instruction. Based on the unit start interval constraint, the start interval time is safety checked. When the start interval time satisfies the unit start interval constraint, it is determined that the safety check of the control instruction under the unit start interval constraint has passed.

[0153] In an exemplary embodiment, if Figure 7 As shown, another unit control method is provided, which is described by taking the method applied to a server as an example, and includes the following steps:

[0154] Step S702: obtaining control instructions for the units in the power plant and determining the target operating conditions corresponding to the control instructions.

[0155] Step S704: Based on the water head constraint of the target working condition, the control instruction is verified for effectiveness under the water head constraint.

[0156] Step S706: Based on the power constraint of the target operating condition, the control instruction is verified for validity under the power constraint.

[0157] Step S708, based on the regulatory constraints of the power plant under the target operating conditions, the control instructions are subjected to safety verification under regulatory constraints.

[0158] Step S710, based on the unit number constraint of the power plant under the target operating condition, the control instruction is subjected to a safety check under the unit number constraint.

[0159] Step S712: Based on the power variation constraint of the power plant under the target operating condition, the control instruction is subjected to a safety check under the power variation constraint.

[0160] Step S714, sending the control instruction to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value corresponding to the control instruction under the target operating condition.

[0161] In this embodiment, the control instructions can be verified for validity based on at least one operating condition constraint of the target operating condition, and the control instructions can be verified for safety based on at least one safety constraint of the power plant. By issuing control instructions that have passed the validity check and the safety check to the unit, the unit can be controlled while ensuring effectiveness and safety, thereby ensuring the output stability of the power plant.

[0162] In order to more clearly illustrate the unit control method provided in the embodiment of the present application, the unit control method is specifically described below with a specific embodiment, but it should be understood that the embodiment of the present application is not limited thereto. Figure 8 As shown, in one exemplary embodiment, the present application also provides a pumped storage unit control method, which specifically includes the following steps:

[0163] 1. Get the set value corresponding to the control instruction.

[0164] 2. Under the target working conditions corresponding to the control instructions, verify the validity of the set values.

[0165] Specifically, see Fig. 9 , the validity verification process is as follows:

[0166] (1) The server obtains the set value and determines the current operating condition and target operating condition of the unit based on the set value.

[0167] (2) Under the target operating conditions, determine whether the set value meets the head constraint; if not, an alarm is issued.

[0168] (3) Under the target operating conditions, determine whether the set value meets the minimum power constraint; if not, return the control of the unit to the in-plant control mode.

[0169] (4) Under the target operating conditions, determine whether the set value meets the maximum power constraint; if not, return the control of the unit to the plant control mode.

[0170] (5) Under the target operating conditions, determine whether the set value meets the maximum output reactive power constraint; if not, return the control of the unit to the in-plant control mode.

[0171] (6) Under the target operating conditions, determine whether the set value meets the maximum input and absorption reactive power constraint; if not, the control of the unit is returned to the plant control mode.

[0172] (7) After the validity check is passed, enter the security check.

[0173] 3. Perform safety check on the set value under the target working conditions corresponding to the control instructions.

[0174] Specifically, see Fig.10 , the security verification process is as follows:

[0175] (1) The server obtains the setting value,

[0176] (2) Under the target working condition, perform logic function calculations and exit if the requirements are not met. This part of the calculation is mainly responsible for reviewing whether the set value meets the requirements of the target working condition.

[0177] (3) Under the target working conditions, perform the regulation limit calculation and exit if the requirements are not met. This part of the calculation is mainly responsible for reviewing whether the set value meets the hydropower regulations.

[0178] (4) Under the target operating conditions, the number of units is calculated. If the requirements are not met, the calculation is exited. This part of the calculation is mainly responsible for reviewing whether the maximum number of units that can be entered and the minimum number of units already in the network corresponding to the set value meet the requirements.

[0179] (5) Under the target operating conditions, the unit start interval calculation is performed, and if the requirements are not met, the calculation is exited. This part of the calculation is mainly responsible for reviewing whether the unit start interval time corresponding to the set value meets the requirements.

[0180] (6) Under the target working condition, the power change rate is calculated. If it does not meet the requirements, the system will exit. This part of the calculation is mainly responsible for checking whether the active power change rate and reactive power change rate corresponding to the set value meet the requirements.

[0181] (7) After the security check is passed, the set value is issued.

[0182] 4. Send the set value to the unit.

[0183] In this embodiment, a validity calculation process and a safety calculation process are set up. The two processes can make real-time judgments and corrections on the set values, thereby ensuring the effectiveness and reliability of the control.

[0184] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0185] Based on the same inventive concept, the embodiment of the present application also provides a unit control device for implementing the unit control method involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in one or more unit control device embodiments provided below can refer to the limitations of the unit control method above, and will not be repeated here.

[0186] In an exemplary embodiment, Fig.11 As shown, a unit control device is provided, including: an instruction acquisition module 1102, a validity verification module 1104, a safety verification module 1106 and an instruction issuing module 1108, wherein:

[0187] The instruction acquisition module 1102 is used to acquire control instructions for the units in the power plant and determine the target operating conditions corresponding to the control instructions. The control instructions have corresponding target output values ​​under the target operating conditions.

[0188] The validity verification module 1104 is used to verify the validity of the control instruction based on at least one operating condition constraint of the target operating condition; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition.

[0189] The safety verification module 1106 is used to perform safety verification on the control instructions based on at least one safety constraint of the power plant when the validity verification of the control instructions under various operating conditions is passed; the safety constraints of the power plant are used to characterize the conditions that need to be met for the safe operation of the power plant.

[0190] The instruction issuing module 1108 is used to issue the control instruction to the unit when the safety check of the control instruction under each safety constraint is passed, so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

[0191] In one of the embodiments, the operating condition constraints include at least a head constraint.

[0192] The validity verification module 1104 is also used to obtain the rated water head of the unit; based on the pre-constructed mapping relationship between the water head and the output value, determine the output value interval corresponding to the target output value of the rated water head; based on the output value interval, perform validity verification on the target output value; when the target output value falls within the output value interval, determine that the validity verification of the control instruction under the water head constraint has passed.

[0193] In one of the embodiments, the operating condition constraint includes at least a power constraint, and the power constraint includes at least one of an active power constraint and a reactive power constraint.

[0194] The validity verification module 1104 is also used to determine the power information of the unit under the control instruction based on the target output value; the power information includes at least one of active information and reactive information; based on the power constraint, the power information is verified for validity; when the power information meets the power constraint, it is determined that the validity verification of the control instruction under the power constraint has passed.

[0195] In one of the embodiments, the safety constraints include at least regulatory constraints under target operating conditions.

[0196] The safety verification module 1106 is also used to determine the demand information of the unit corresponding to the procedure constraints under the control instruction based on the target output value; based on the procedure constraints, perform safety verification on the demand information; when the demand information meets the procedure constraints, determine that the safety verification of the control instruction under the procedure constraints has passed.

[0197] In one of the embodiments, the safety constraint includes at least a constraint on the number of units under the target operating condition, and the constraint on the number of units includes at least one of a constraint on the number of accessible units corresponding to the target operating condition and a constraint on the number of units already in the network.

[0198] The safety verification module 1106 is also used to determine the unit number information of the unit under the control instruction based on the target output value; the unit number information includes at least one of the number of accessible units and the number of units already online; based on the unit number constraint, the unit number information is safety verified; when the unit number information satisfies the unit number constraint, it is determined that the safety verification of the control instruction under the unit number constraint has passed.

[0199] In one of the embodiments, the safety constraint includes at least a power variation constraint under a target operating condition, and the power variation constraint includes an active power variation constraint and a reactive power variation constraint.

[0200] The safety verification module 1106 is also used to determine the power change information of the unit under the control instruction based on the target output value; the power change information includes at least one of the active power change rate and the reactive power change rate of the unit; based on the power change constraint, the power change information is safety verified; when the power change information satisfies the power change constraint, it is determined that the safety verification of the control instruction under the power change constraint has passed.

[0201] Each module in the above-mentioned unit control device can be implemented in whole or in part by software, hardware or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute the operations corresponding to each module.

[0202] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Fig.12 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. Among them, the processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the operating data of the unit as well as the operating condition constraints and safety constraints. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a unit control method is implemented.

[0203] Those skilled in the art will understand that Fig.12 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0204] In an exemplary embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0205] In an exemplary embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0206] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0207] A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, an artificial intelligence (AI) processor, etc., but are not limited to this.

[0208] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0209] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A unit control method, characterized in that: The method comprises: Obtaining a control instruction for a unit in a power plant, and determining a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition; Based on at least one operating condition constraint of the target operating condition, the control instruction is verified for validity; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition; When the validity check of the control instruction under each operating condition constraint is passed, the control instruction is subjected to safety check based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely; When the control instruction passes the safety check under each safety constraint, the control instruction is sent to the unit so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

2. The method according to claim 1, characterized in that The working condition constraints at least include head constraints; The performing validity verification on the control instruction based on at least one operating condition constraint of the target operating condition includes: Obtaining the rated water head of the unit; Based on a pre-constructed mapping relationship between water head and output value, determining an output value interval corresponding to the target output value of the rated water head; Based on the output value interval, performing validity verification on the target output value; When the target output value falls within the output value interval, it is determined that the validity check of the control instruction under the water head constraint has passed.

3. The method according to claim 1, characterized in that The operating condition constraint includes at least a power constraint, and the power constraint includes at least one of an active power constraint and a reactive power constraint; The performing validity verification on the control instruction based on at least one operating condition constraint of the target operating condition includes: Based on the target output value, determining the power information of the unit under the control instruction; the power information includes at least one of active information and reactive information; Based on the power constraint, performing validity verification on the power information; In a case where the power information satisfies the power constraint, it is determined that the validity check of the control instruction under the power constraint passes.

4. The method according to any one of claims 1 to 3, characterized in that: The safety constraints at least include the procedural constraints under the target working condition; The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes: Based on the target output value, determining the demand information of the unit corresponding to the regulation constraint under the control instruction; Based on the regulation constraints, performing security verification on the demand information; In a case where the requirement information satisfies the regulation constraint, it is determined that the safety check of the control instruction under the regulation constraint passes.

5. The method according to any one of claims 1 to 3, characterized in that: The safety constraint at least includes a unit number constraint under the target operating condition, and the unit number constraint includes at least one of an accessible unit number constraint and an on-grid unit number constraint corresponding to the target operating condition; The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes: Based on the target output value, determine the number of units of the unit under the control instruction; the number of units information includes at least one of the number of units that can be entered and the number of units that have been connected to the network; Based on the unit number constraint, performing safety verification on the unit number information; In a case where the unit number information satisfies the unit number constraint, it is determined that the safety check of the control instruction under the unit number constraint has passed.

6. The method according to any one of claims 1 to 3, characterized in that: The safety constraint at least includes a power variation constraint under the target operating condition, and the power variation constraint includes an active power variation constraint and a reactive power variation constraint; The performing safety verification on the control instruction based on at least one safety constraint of the power plant includes: Based on the target output value, determining the power change information of the unit under the control instruction; the power change information includes at least one of the active power change rate and the reactive power change rate of the unit; Based on the power change constraint, performing a security check on the power change information; In a case where the power change information satisfies the power change constraint, it is determined that the safety check of the control instruction under the power change constraint has passed.

7. A unit control device, characterized in that: The device comprises: An instruction acquisition module is used to acquire a control instruction for a unit in a power plant and determine a target operating condition corresponding to the control instruction; the control instruction has a corresponding target output value under the target operating condition; A validity verification module, used to verify the validity of the control instruction based on at least one operating condition constraint of the target operating condition; the operating condition constraint of the target operating condition is used to characterize the conditions that need to be met to enter the target operating condition; A safety verification module, configured to, when the validity verification of the control instruction under each operating condition constraint is passed, perform safety verification on the control instruction based on at least one safety constraint of the power plant; the safety constraint of the power plant is used to characterize the conditions that need to be met when the power plant is operating safely; The instruction issuing module is used to issue the control instruction to the unit when the safety check of the control instruction under various safety constraints is passed, so that the unit enters the target operating condition and the output value of the unit under the target operating condition reaches the target output value.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. 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 6 are implemented.

10. A computer program product, comprising a computer program, 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 6 are implemented.

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