Off-grid control method and system for backup power supply of wind turbine generator

Abstract

The invention provides a wind turbine generator backup power supply off-grid control method and system, and the method comprises the steps: S1, obtaining the first state information of a wind turbine generator in real time through an SCADA system, generating a first control instruction according to the first state information, and then transmitting the first control instruction to a satellite system; s2, after the satellite system receives the first control instruction, second state information of the wind turbine generator is obtained, and then the second state information and the first control instruction are sent to the SCADA system and a power controller of the wind turbine generator; s3, the SCADA system generates a second control instruction according to the second state information and sends the second control instruction to a power supply controller of the wind turbine generator; and S4, the power supply controller starts a backup power supply to supply power to the wind turbine generator according to the first control instruction and the second control instruction. The problem that in the prior art, a wind turbine generator is in an off-grid power failure state and cannot be remotely controlled and monitored is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of wind power generation, and in particular to a method and system for controlling off-grid backup power supply of a wind turbine generator set. Background Art

[0002] In order to cope with extreme wind conditions, offshore wind power development projects have a large workload. In order to reduce the design cost of the unit, it is necessary to design a backup power supply for the unit in response to extreme offshore working conditions such as power outages (grid system disconnection or power outage due to faults) to provide operating power for the unit and reduce the unit load design requirements. However, in the prior art, when the wind turbine unit is off-grid and power-off, the unit is shut down and the ring network cannot operate normally, the unit communication is interrupted, and remote control and monitoring cannot be achieved. The backup power supply can only rely on a pre-set self-starting program to automatically start / shut down the backup power supply to supply power to the wind turbine by judging whether there is current passing through the connection points between the backup power supply and the unit. However, this type of automatic starting program is easily affected by power fluctuations, resulting in abnormal startup of the self-starting program and causing current disorder inside the wind turbine unit. Summary of the invention

[0003] In view of the deficiencies in the prior art, the present invention provides a method and system for controlling an off-grid backup power supply of a wind turbine generator set, which solves the problem in the prior art that the wind turbine generator set cannot be remotely controlled or monitored when it is off-grid and power-off.

[0004] According to an embodiment of the present invention, a method for controlling off-grid backup power supply of a wind turbine generator system includes:

[0005] S1: The SCADA system acquires first status information of the wind turbine in real time, generates a first control instruction according to the first status information, and then sends the first control instruction to the satellite system;

[0006] S2: After receiving the first control instruction, the satellite system obtains second state information of the wind turbine generator set, and then sends the second state information and the first control instruction to the SCADA system and the power controller of the wind turbine generator set respectively;

[0007] S3: The SCADA system generates a second control instruction according to the second state information, and sends the second control instruction to the power supply controller of the wind turbine generator set;

[0008] S4: The power controller starts the backup power supply to supply power to the wind turbine according to the first control instruction and the second control instruction.

[0009] Preferably, after acquiring the first status information, the SCADA system sends the first status information to the satellite system. After acquiring the second status information, the satellite system compares the first status information with the second status information. If the first status information and the second status information are exactly the same, the first control instruction is sent to the wind turbine set.

[0010] Preferably, if the first status information and the second status information are not completely the same, the satellite system sends a resend instruction to the SCADA system, and after receiving the resend instruction, the SCADA system repeats step S1.

[0011] Preferably, the first status information and the second status information both include an average wind speed, a grid status and an operating mode of the wind turbine.

[0012] Preferably, the first control instruction includes a first switching instruction and a first holding instruction, and the second control instruction includes a second switching instruction and a second holding instruction;

[0013] If the average wind speed of the wind turbine is greater than the preset value, the grid state is in an off-grid state and the working mode is in a grid-connected operation mode, the SCADA system will generate a first switching instruction or a second switching instruction. If the average wind speed of the wind turbine is less than the preset value or the grid state is in a grid-connected state, the SCADA system will generate a first holding instruction or a second holding instruction.

[0014] Preferably, in S4, if the first control instruction and the second control instruction are respectively the first switching instruction or the second switching instruction, the backup power supply is started to supply power to the wind turbine set.

[0015] On the other hand, according to an embodiment of the present invention, a wind turbine generator backup power supply off-grid control system is also provided. The system adopts the above-mentioned wind turbine generator backup power supply off-grid control method, including:

[0016] A wind turbine generator set, wherein the wind turbine generator set comprises a backup energy source, a main control system, a converter system and a power controller, wherein the backup energy source and the converter system are both connected to the main control system, and the power controller is connected to the backup energy source;

[0017] A satellite system, comprising a satellite terminal and a communication server;

[0018] A centralized control center, the centralized control center comprising a SCADA system and a management server connected to each other;

[0019] The power supply controller, the communication server and the SCADA system are connected to communicate with each other in pairs.

[0020] Preferably, the communication server is connected to the power controller or the SCADA system via an RS485 summary interface, and the power controller and the SCADA system are connected via TCP.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The SCADA system obtains the first status information of the wind turbine set in real time, and determines in real time whether the wind turbine set is in an off-grid state and whether it needs to be switched to an off-grid operation mode. If it needs to be switched to an off-grid operation mode, a first control instruction is generated and forwarded to the wind turbine set by the satellite system. After that, the satellite system also obtains the second status information of the wind turbine set and sends the second status information to the SCADA system and generates a second control instruction, which is then sent to the wind turbine set. The wind turbine set determines whether it needs to start the backup power supply to power the wind turbine set based on the first control instruction and the second control instruction. In this way, by adopting satellite communication and network dual communication methods, satellite system, backup power supply and SCADA system remote control technology, a dual communication, three control and multi-redundancy design is formed to achieve stable intelligent off-grid operation control of the wind turbine set, and the accuracy of remote control is ensured by comparing and judging the two control instructions. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an off-grid control flow chart of an embodiment of the present invention.

[0024] Figure 2 2 is an architecture diagram of an off-grid control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0025] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0026] like Figure 1 As shown, an embodiment of the present invention proposes a method for controlling off-grid backup power supply of a wind turbine generator set, comprising:

[0027] S1: The SCADA system acquires first status information of the wind turbine in real time, generates a first control instruction according to the first status information, and then sends the first control instruction to the satellite system;

[0028] The first status information includes the average wind speed, grid status and working mode of the wind turbine set. The grid status includes the grid-connected status and the off-grid status. The working mode includes the grid-connected operation mode and the off-grid operation mode. When a grid failure occurs, the grid is cut off and the grid status of the wind turbine set will automatically change to the off-grid status, but the working mode will not change and will remain in the grid-connected operation mode.

[0029] In the operation of a wind farm, the SCADA system, as the core system of wind farm operation management, mainly collects operation data of various parts of the wind farm in real time, monitors and controls the wind turbine generator set, and ensures the safe, stable and efficient operation of the wind farm. In the present invention, the SCADA system obtains the first state information of the wind turbine generator set in real time and completes the judgment according to the first state information, generates the first control instruction and sends the first control instruction to the satellite system, and then the satellite system forwards the first control instruction to the wind turbine generator set to operate the backup power supply, thereby realizing the information interaction and operation control of the unit, and after the unit is normally off-grid, the ring network communication of the wind turbine generator set can be established, and the SCADA system can realize the all-round safety monitoring of the unit.

[0030] Among them, the first control instruction includes a first switching instruction and a first holding instruction. If the average wind speed of the wind turbine is greater than a preset value, the grid state is in an off-grid state and the working mode is an off-grid operation mode, the SCADA system will generate a first switching instruction. If the average wind speed of the wind turbine is less than a preset value or the grid state is in a grid-connected state, the SCADA system will generate a first holding instruction.

[0031] S2: After receiving the first control instruction, the satellite system obtains second state information of the wind turbine generator set, and then sends the second state information and the first control instruction to the SCADA system and the power controller of the wind turbine generator set respectively;

[0032] The second status information is the same as the first status information, and both include the average wind speed, grid status and working mode of the wind turbine set. After the satellite system obtains the second status information, the first status information and the second status information are compared. If the first status information and the second status information are exactly the same, the first control instruction will be sent from the satellite system to the wind turbine set. If the first status information and the second status information are not exactly the same, the satellite system sends a retransmission instruction to the SCADA system. After receiving the retransmission instruction, the SCADA system repeats step S1 to re-acquire the first status information of the wind turbine set, so as to compare and verify the status of the wind turbine set to ensure that the acquired status information of the wind turbine set is relatively accurate.

[0033] Afterwards, the satellite system sends the second status information to the power controller of the wind turbine generator set.

[0034] S3: The SCADA system generates a second control instruction according to the second state information, and sends the second control instruction to the power supply controller of the wind turbine generator set;

[0035] The second control instruction also includes a second switching instruction and a second holding instruction. If the average wind speed of the wind turbine is greater than a preset value, the grid state is in an off-grid state and the working mode is an off-grid operation mode, the SCADA system will generate a second switching instruction. If the average wind speed of the wind turbine is less than a preset value or the grid state is in a grid-connected state, the SCADA system will generate a second holding instruction.

[0036] Then the second control instruction or the second holding instruction is sent to the power supply controller of the wind turbine generator set.

[0037] S4: The power controller starts the backup power supply to supply power to the wind turbine according to the first control instruction and the second control instruction.

[0038] After receiving the first control instruction and the second control instruction sent by the satellite system and the SCADA system, the power controller will first determine the time when the two control instructions are received. If the reception time of the two control instructions differs by more than 2 minutes, it means that the two control instructions represent two control instructions that are not issued for the opening and closing of the same function, so the power controller maintains the current state and continues to wait.

[0039] If the reception time of the two control instructions differs within 2 minutes, it indicates that the two control instructions are instructions for opening and closing the same function. At this time, the types of the two control instructions are judged. If the two control instructions are the first switching instruction and the second switching instruction respectively, the controller starts the backup power supply.

[0040] If the two control instructions are respectively the first switching instruction and the second holding instruction or the first holding instruction and the second switching instruction, it means that the first state information or the second state information is lost or tampered with during the sending process. At this time, instructions will be sent to the satellite system and the SCADA system to repeat steps S1-S4.

[0041] On the other hand, Figure 2 As shown, an embodiment of the present invention further provides a wind turbine backup power supply off-grid control system, which adopts the above-mentioned wind turbine backup power supply off-grid control method, including:

[0042] A wind turbine generator set comprises a backup energy source, a main control system, a converter system and a power supply controller. The backup energy source and the converter system are both connected to the main control system, and the power supply controller is connected to the backup energy source.

[0043] The main function of the converter system is to control the torque of the generator and feed the electric energy to the grid to realize the variable speed constant frequency control of the generator. The converter system is mainly composed of the grid-side circuit breaker, grid-side filter, grid-side power unit, Chopper unit, machine-side power unit, du / dt filter, machine-side load switch, etc. It communicates with the main control system of the wind turbine generator set, receives the control instructions of the main control system, and uploads the status information of the converter to the main control system or remote monitoring system. Under this off-grid operation control scheme, the converter system is controlled to work in off-grid mode, which is different from the normal power generation control mode of the wind turbine. That is, relying on the bidirectional power conversion properties of the IGBT on the grid side and the machine side of the converter, the converter machine side works in constant voltage (bus voltage) mode, and the grid side works in voltage source mode (that is, when the converter is working, it is equivalent to a power supply for external equipment). The converter is controlled to start the machine side first to establish the DC bus voltage; then the grid side is started and works in voltage source mode to achieve off-grid power generation, ensuring the output power of the wind turbine changes and the output of electric energy with constant frequency.

[0044] Satellite system, the satellite system adopts the Beidou satellite short message communication system, including satellite terminals and communication servers. In this solution, the satellite system communication realizes the data transmission of the backup power supply and SCADA system through the communication server. The satellite system uses the RS485 bus interface to connect with the power controller and SCADA system of the wind turbine.

[0045] The satellite system is one of the technologies used to remotely control the off-grid operation of wind turbines. In the event of a power outage, it ensures the stability and reliability of data transmission and unit control.

[0046] The centralized control center includes a SCADA system and a management server that are interconnected. During the operation of the wind farm, the SCADA system, as the core system for wind farm operation management, mainly collects real-time operation data from all parts of the wind farm, and monitors and controls wind turbines to ensure safe, stable and efficient operation of the wind farm. In this solution, the SCADA system server and the satellite system communication server are connected through the RS485 interface to realize data interaction between the SCADA system and the Beidou system. The SCADA system automatically completes the judgment based on the status of the wind farm unit, and sends control instructions to the satellite system to control the operation of the backup power supply, thereby realizing unit information interaction and operation control. After the unit is normally off-grid, the ring network communication of the wind turbine can be established, and the SCADA system can realize all-round safety monitoring of the unit. Therefore, the SCADA system is also one of the ways to remotely control the off-grid operation of wind turbines.

[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for controlling off-grid backup power supply of a wind turbine generator set, characterized in that: include: S1: The SCADA system acquires first status information of the wind turbine in real time, generates a first control instruction according to the first status information, and then sends the first control instruction to the satellite system; S2: After receiving the first control instruction, the satellite system obtains second state information of the wind turbine generator set, and then sends the second state information and the first control instruction to the SCADA system and the power controller of the wind turbine generator set respectively; S3: The SCADA system generates a second control instruction according to the second state information, and sends the second control instruction to the power supply controller of the wind turbine generator set; S4: The power controller starts the backup power supply to supply power to the wind turbine according to the first control instruction and the second control instruction.

2. A wind turbine backup power supply off-grid control method as claimed in claim 1, characterized in that: After acquiring the first status information, the SCADA system sends the first status information to the satellite system. After acquiring the second status information, the satellite system compares the first status information with the second status information. If the first status information and the second status information are exactly the same, the first control instruction is sent to the wind turbine.

3. A wind turbine backup power supply off-grid control method as claimed in claim 2, characterized in that: If the first state information and the second state information are not completely the same, the satellite system sends a resend instruction to the SCADA system, and after receiving the resend instruction, the SCADA system repeats step S1.

4. A wind turbine backup power supply off-grid control method as claimed in claim 2, characterized in that: The first status information and the second status information both include the average wind speed, grid status and working mode of the wind turbine.

5. A wind turbine backup power supply off-grid control method as claimed in claim 1, characterized in that: The first control instruction includes a first switching instruction and a first holding instruction, and the second control instruction includes a second switching instruction and a second holding instruction; If the average wind speed of the wind turbine is greater than the preset value, the grid state is in an off-grid state and the working mode is in a grid-connected operation mode, the SCADA system will generate a first switching instruction or a second switching instruction. If the average wind speed of the wind turbine is less than the preset value or the grid state is in a grid-connected state, the SCADA system will generate a first holding instruction or a second holding instruction.

6. A wind turbine backup power supply off-grid control method as claimed in claim 5, characterized in that: In S4, if the first control instruction and the second control instruction are respectively the first switching instruction or the second switching instruction, the backup power supply is started to supply power to the wind turbine set.

7. A wind turbine backup power supply off-grid control system, characterized in that: The system adopts a wind turbine backup power off-grid control method as claimed in any one of claims 1 to 6, comprising: A wind turbine generator set, wherein the wind turbine generator set comprises a backup energy source, a main control system, a converter system and a power controller, wherein the backup energy source and the converter system are both connected to the main control system, and the power controller is connected to the backup energy source; A satellite system, comprising a satellite terminal and a communication server; A centralized control center, the centralized control center comprising a SCADA system and a management server connected to each other; The power supply controller, the communication server and the SCADA system are connected to communicate with each other in pairs.

8. A wind turbine backup power off-grid control system as claimed in claim 7, characterized in that: The communication server is connected to the power controller or the SCADA system via an RS485 summary interface, and the power controller and the SCADA system are connected via TCP.

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