Df unit oat variable pitch blade interlock control system and method

Abstract

The application discloses a kind of double-fed unit OAT variable pitch blade interlock control system and method, system includes central control interlock switching module, three-axis interlock execution module, signal feedback module and PMM logic control module, central control interlock switching module is located in pitch central control box, three three-axis interlock execution modules are respectively arranged in the interlock relay in corresponding pitch shaft box, relay control contact point is connected with corresponding shaft PMC enable control loop;Signal feedback module is connected with interlock terminal row, interlock change-over switch respectively, and access the DI end of unit PLC through slip ring standby channel;PMM logic control module programmable DO output end is connected with interlock relay coil.The application relies on hardware loop and logic determination double protection, can be locked during operation and maintenance emergency feathering action, realize single-shaft blade angle overrun independent locking, and real-time upload working state, avoid blade accidental rotation, effectively improve the operation safety and operation reliability of double-fed unit OAT operation condition.

Description

Technical Field

[0001] This invention belongs to the field of wind turbine pitch control safety protection technology, specifically relating to a doubly fed wind turbine OAT pitch blade interlock control system and method. Background Technology

[0002] Currently, under OAT (Out of Attention) operation conditions, the pitch system of doubly-fed wind turbine generators lacks a dedicated blade interlock protection architecture. Existing pitch control loops lack independent hardware interlocking mechanisms, and the unit's conventional control logic cannot provide angle-linked constraints for the three-axis blades. During maintenance, the EFC (Emergency Feathering Control) signal loop and the PMC (Programmable Controller) enable control loops for each axis lack hardware isolation and interlocking switching mechanisms, making single-axis blade malfunctions and uncontrolled angle deflection prone to occur, posing significant safety hazards. Traditional solutions rely solely on the unit's software logic for limit judgments, lacking dedicated central control switching components, distributed execution components, and status feedback links. The software logic is susceptible to program disturbances and signal interference, easily leading to misjudgments or failures. Furthermore, existing pitch cabinets and pitch shaft boxes lack corresponding electrical interlocking wiring layouts, and lack a unified design for the utilization of independent terminal blocks, interlocking relays, and slip ring backup channels. This prevents the achievement of closed-loop protection for real-time blade angle monitoring, hard circuit disconnection, and real-time status transmission, failing to meet the safety, reliability, and stable operation requirements of OAT operations. Summary of the Invention

[0003] The purpose of this invention is to provide a doubly fed turbine OAT pitch blade interlock control system and method to solve the technical defects of existing doubly fed turbine OAT operating conditions pitch systems, such as lack of independent hardware interlock, reliance on software limits which are prone to failure, and lack of closed-loop protection.

[0004] To achieve the above objectives, this application provides the following technical solution: A first aspect of this application provides an OAT (Out-of-Atmosphere Loading) blade interlock control system for a doubly-fed generator unit, comprising: The central control interlock switching module is installed inside the pitch control box and includes an interlock changeover switch and an interlock terminal block. The normally closed contact of the interlock changeover switch is connected in series to the EFC emergency feathering signal circuit, and the signal terminal of the interlock changeover switch is electrically connected to the interlock terminal block. The three-axis interlocking actuator module is electrically connected to the interlocking terminal block. The three-axis interlocking actuator module includes three interlocking relays, which are respectively installed in the corresponding strain gauge propeller shaft box. The control contacts of the interlocking relays are connected in series to the PMC enable control circuit of the corresponding axis. The signal feedback module is also electrically connected to the interlock terminal block. One end of the signal feedback module is electrically connected to the interlock changeover switch, and the other end is electrically connected to the DI terminal of the unit PLC via the slip ring spare channel. The PMM logic control module has a programmable DO output terminal that is electrically connected to the coil of the interlock relay. It outputs control signals according to the blade angle range to drive the interlock relay to achieve triaxial blade interlock protection.

[0005] In one optional embodiment, the interlocking changeover switch is located at the original lighting switch mounting position of the pitch control box; The other set of normally closed contacts of the interlock changeover switch is electrically connected at one end to the interlock terminal block and at the other end to the signal feedback module to form an interlock status feedback loop.

[0006] In one optional embodiment, the interlock terminal block is an independent wiring terminal block, and the wiring terminals of the interlock terminal block are electrically connected one-to-one with the signal output terminal of the interlock changeover switch, the control terminals of the three interlock relays, and the input terminal of the signal feedback module, forming a multi-channel interlock wiring connection.

[0007] In one optional embodiment, a mounting hole is provided on the side plate of the pitch shaft box, and a cable locking head for cable sealing and insertion is fixedly provided at the mounting hole. The connection line of the interlock relay is electrically connected to the interlock terminal block via the cable locking head.

[0008] In one alternative embodiment, the interlocking relay is a DC 24V powered relay.

[0009] In one optional embodiment, the PMM logic control module has a built-in configurable angle threshold parameter group, and the PMM logic control module outputs a corresponding control signal to the interlock relay based on the angle threshold parameter group.

[0010] In one optional embodiment, the angle threshold parameter set includes a lower limit value for the blade angle, an upper limit value for the blade angle, and interlock signal output mode configuration parameters.

[0011] In one optional embodiment, the input terminal of the signal feedback module is electrically connected to the feedback contact of the interlock changeover switch, and the output terminal of the signal feedback module is electrically connected to the digital input terminal of the engine room PLC through the slip ring spare channel, for transmitting the status signal of the interlock changeover switch to the unit PLC.

[0012] In one optional embodiment, when the angle of any one shaft blade exceeds the set angle range, the PMM logic control module controls the interlock relay of the corresponding shaft to de-energize and disconnect, thereby cutting off the PMC enable signal of that shaft and thus locking the position of the corresponding blade.

[0013] A second aspect of this application provides a doubly-fed turbine OAT (Out-of-Atmosphere) pitch blade interlock control method, wherein the method employs the doubly-fed turbine OAT pitch blade interlock control system as described above, comprising: Switch the interlock switch of the central control interlock switching module to maintenance mode so that the EFC emergency feathering signal circuit remains disconnected; The PMM logic control module collects and monitors the angle information of the triaxial propeller blades in real time based on a preset angle threshold parameter group. If any blade angle is within the safe range set by the angle threshold parameter group, the PMM logic control module outputs a control signal to energize the interlock relay of the corresponding shaft, thereby activating the PMC enable control loop of that shaft and allowing the blade to perform angle adjustment. If any blade angle exceeds the safe range, the PMM logic control module stops outputting control signals, causing the interlock relay of the corresponding shaft to de-energize and disconnect, thereby cutting off the PMC enable signal of that shaft and locking the blade position. The signal feedback module uploads the status signal of the interlock changeover switch to the unit PLC through the slip ring backup channel to achieve full-process interlock protection control.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting up a central control interlock switching module, a three-axis interlock execution module, a signal feedback module, and a PMM logic control module, a complete blade interlock control architecture is constructed to achieve safe control of blade angles during maintenance. The interlock changeover switch is connected in series with the EFC emergency feathering circuit, which can prohibit emergency feathering during maintenance. The interlock relay is connected in series with the PMC enable circuit to achieve independent locking of a single axis when it exceeds the limit. The signal feedback module uploads the status in real time, and the PMM module drives the execution according to the angle range, achieving dual protection from both hardware and logic levels. This effectively avoids accidental blade rotation during maintenance and significantly improves the safety of the unit.

[0015] 2. Install the interlock changeover switch in the original lighting switch location without additional drilling or cabinet modifications, simplifying construction and reducing modification costs; through another set of normally closed contacts, an independent feedback loop is formed, enabling stable transmission of the interlock status, synchronizing switch action and status feedback, ensuring that maintenance personnel and the control system can monitor the interlock mode status in real time, improving system reliability and maintainability, and avoiding signal interference and wiring confusion.

[0016] 3. Independent interlocking terminal blocks are used to achieve orderly connection of multiple signals, which are respectively connected to the transfer switch, interlocking relay and feedback module to form an independent wiring channel, avoiding mixed wiring, short circuit and signal crosstalk.

[0017] 4. Mounting holes and cable locking heads are provided on the side plate of the shaft box to achieve sealed cable insertion and fixation, preventing dust and moisture from entering the box and ensuring the safe operation of electrical components; the connecting wires are orderly connected to the interlocking terminal block through the locking heads, so that the wiring specifications and protection level meet the standards, improving the durability and reliability of the system in the complex environment of the wind turbine hub, and reducing the risk of failure caused by line wear and loosening.

[0018] 5. The interlock relay is limited to DC 24V power supply type, which matches the standard power supply voltage of the wind turbine pitch system. No additional power supply module is required, which has strong compatibility and simple wiring.

[0019] 6. A configurable angle threshold parameter group is set in the PMM logic control module, which enables the system to flexibly set the protection range according to different units and different operating conditions, making it more applicable.

[0020] 7. The angle threshold parameter group includes the lower angle limit, the upper angle limit, and the output mode parameters, which enables the PMM logic control module to have complete judgment criteria, accurately identify whether the blade is in the safe range, and output interlock signals according to the set mode.

[0021] 8. The status of the changeover switch is transmitted to the PLC digital input terminal via the slip ring backup channel through the signal feedback module, realizing reliable transmission of status signals between the nacelle and the hub. Real-time feedback enables the upper system to identify the interlock mode in a timely manner, and works with the wind turbine main control logic to realize linkage protection, which facilitates remote monitoring, fault recording and safety interlock, and improves the overall intelligent level of wind turbine operation and maintenance.

[0022] 9. When any axis exceeds the safe range, the PMM module immediately cuts off the corresponding relay, disconnects the PMC enable signal, and locks the blade position to prevent the angle from continuing to deviate. The independent control of a single axis does not affect the normal operation of other axes, which not only ensures maintenance safety but also improves the fault tolerance of the system and avoids overall failure caused by a single axis abnormality. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of an OAT (Output Adjustment and Automated Transmission) blade interlock control system for a doubly fed turbine generator set provided by this invention; In the diagram: 1. Central control interlock switching module; 101. Interlock changeover switch; 102. Interlock terminal block; 2. Three-axis interlock execution module; 201. Interlock relay; 3. Signal feedback module; 4. PMM logic control module; 5. EFC emergency feathering signal circuit; 6. PMC enable control circuit; 7. Unit PLC. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] To address the technical deficiencies mentioned in the background section, this embodiment provides an OAT (Output Adjustment and Activation) control system and method for doubly fed turbines.

[0029] The present invention will now be described in further detail with reference to the accompanying drawings: like Figure 1As shown, in a first aspect of the present invention, an OAT (Out-of-Air) pitch interlock control system for a doubly-fed generator (DFG) turbine is provided, comprising: a central control interlock switching module 1, installed inside the pitch control box, including an interlock changeover switch 101 and an interlock terminal block 102, wherein the normally closed contact of the interlock changeover switch 101 is connected in series to the EFC (Emergency Feathering) signal circuit 5, and the signal terminal of the interlock changeover switch 101 is electrically connected to the interlock terminal block 102; and a three-axis interlock execution module 2, electrically connected to the interlock terminal block 102, the three-axis interlock execution module 2 including three interlock relays 201, which are respectively installed in... Inside the corresponding propeller shaft box, the control contacts of the interlock relay 201 are connected in series to the PMC enable control circuit 6 of the corresponding shaft; the signal feedback module 3 is also electrically connected to the interlock terminal block 102, one end of the signal feedback module 3 is electrically connected to the interlock changeover switch 101, and the other end is electrically connected to the DI terminal of the unit PLC7 via the slip ring spare channel; the PMM logic control module 4, the programmable DO output terminal of the PMM logic control module 4 is electrically connected to the coil of the interlock relay 201, and outputs control signals according to the blade angle range to drive the interlock relay 201 to achieve three-axis blade interlock protection.

[0030] In this embodiment, the central control interlock switching module 1 is installed inside the pitch control box. The pitch control box is the original standard cabinet of the unit, which integrates the original circuits such as 24VDC overvoltage protection, 24VDC distribution control, lubrication pump control, and shaft box signal interface. During the modification process, all original components and wiring are retained, and only the interlock changeover switch 101 and interlock terminal block 102 are added at the designated locations.

[0031] The interlocking changeover switch 101 adopts a multi-layer rotary structure and is installed in the original lighting switch mounting position of the pitch control box. During installation, the original lighting switch contacts are removed and fixed to the emergency stop switch bracket to ensure that the original lighting circuit function is not affected. At the same time, a special protective cover is added to the interlocking changeover switch 101 to prevent accidental contact during operation and maintenance.

[0032] Interlocking terminal block 102 is an independently added terminal block. The model is consistent with the original terminal block in the cabinet. The installation position is determined according to the internal space of the central control box. It can be slightly adjusted for different wind fields. After installation, a special yellow label with black text is affixed. The label content is X7. Two identical labels are affixed for each set of modification to facilitate wiring and identification during later maintenance.

[0033] The three-axis interlocking execution module 2 includes three interlocking relays 201, which correspond to the No. 1, No. 2, and No. 3 propeller blades of the unit, respectively. They are independently installed inside the three pitch shaft boxes, which are the original shaft control cabinets of the unit. The pitch shaft boxes integrate components such as power supply modules, PMC drive modules, PMM control modules, motor temperature detection, encoder interfaces, and EFC emergency feathering interfaces.

[0034] Remove the side plate end cap from the pitch shaft box side plate, and make mounting holes according to the cable specifications on site. Fix cable locking heads at the mounting holes. Common cable locking head specifications include M16, M22, and M25. The specific one should be selected according to the actual situation of the wind farm. This will achieve the sealed passage of the interlock relay 201 connection wire, prevent dust and moisture from entering the shaft box, and improve the protection level of electrical components.

[0035] The interlock relay 201 is a DC 24V powered relay, model LY2N-D2 DC24V. It is installed in the reserved mounting position inside the axle box and the fixing method is consistent with the original relay in the axle box to ensure that it does not loosen or fall off during operation. Each interlock relay 201 is affixed with a special identification label, which is marked 1K3, 2K3 and 3K3 respectively, so that the three axes can be independently distinguished.

[0036] The signal feedback module 3 is a signal relay and transmission circuit. One end is connected to the feedback contact of the interlocking changeover switch 101, and the other end is electrically connected to the DI terminal of the unit PLC7 through the slip ring spare channel. The number of slip ring spare channels is determined according to the actual configuration of the unit. In this embodiment, the idle spare channels of the unit are used, which do not occupy the original signal channels.

[0037] PMM logic control module 4 is the original pitch control module of the unit, which has programmable logic and DO output functions. No hardware replacement is required during the retrofit. Only the idle DO port is enabled. The programmable DO output terminal is electrically connected to the coils of the three interlocking relays 201 one by one. Angle monitoring and relay drive control are realized through software parameter configuration.

[0038] In this embodiment, the interlocking changeover switch 101 includes multiple sets of contacts, one of which is a normally closed contact connected in series to the EFC emergency feathering signal circuit 5. When the interlocking changeover switch 101 is switched to maintenance mode, this set of normally closed contacts is opened, keeping the EFC emergency feathering signal circuit 5 in an open state, preventing the emergency feathering action from being triggered during operation and maintenance, and ensuring the safety of maintenance personnel in the hub. The signal terminal of the interlocking changeover switch 101 is directly electrically connected to the interlocking terminal block 102, serving as a relay node for multiple signals.

[0039] Another set of normally closed contacts of the interlock changeover switch 101 constitutes a feedback contact. One end of the feedback contact is electrically connected to the interlock terminal block 102, and the other end is electrically connected to the input terminal of the signal feedback module 3, forming an independent interlock status feedback loop, which transmits the remote / maintenance mode signal of the interlock changeover switch 101 to the outside in real time.

[0040] Interlock terminal block 102 is a wiring transfer unit. The wiring terminals are electrically connected to the signal output terminal of interlock changeover switch 101, the control terminals of the three interlock relays 201, and the input terminal of signal feedback module 3, forming multiple independent interlock wiring channels. All wiring uses 0.75mm² wires, and the wire colors follow the project specifications. The wires inside the control box are mainly orange and brown. The two ends of the wires use 1.0-8 tubular single-crimped lugs for a firm crimp. The wire length is determined according to the actual path. The length of the wires inside the control box is controlled within 1500mm. When wiring, the wires are fixed along the original wiring harness of the cabinet and do not cross with the power cables to avoid signal interference.

[0041] The new wiring harness inside the central control box was installed according to the wire installation process card. Port 1a of terminal block X7 was connected to port 11 of interlock switch 101 via an orange wire. Port 4a of terminal block X7 was connected to port 31 of interlock switch 101 via an orange wire. Ports 34 and 32, 24 and 22, and 14 and 12 of interlock switch 101 were connected via short wires, each only 100mm long, to ensure internal contact connectivity. Port 52 of interlock switch 101 was connected to port 1B of X24V terminal block X2 via a brown wire to obtain 24V power. Port 51 was connected to port 3 of X1.4 terminal block X1.4 via a brown wire to ensure a power circuit connection. After all wiring was completed, the wire numbers and continuity were checked to ensure there were no short circuits or open circuits.

[0042] The internal wiring of the three pitch shaft boxes is completely identical. Taking the No. 1 shaft box as an example, the control contact of the interlock relay 201 is connected in series to the PMC enable control circuit 6 of the corresponding shaft, specifically to the X4:5 (Enable) port of the PMC module. When the interlock relay 201 is energized and engaged, the contact closes to conduct the PMC enable signal, allowing blade angle adjustment; when the interlock relay 201 is de-energized and disengaged, the contact opens to cut off the PMC enable signal and lock the blade position.

[0043] One end of the coil of the interlock relay 201 is connected to the programmable DO output terminal of the PMM logic control module 4 via a brown wire, specifically to the X13:1 port of the PMM module. The other end is connected to the 0V common terminal inside the shaft box via a dark blue wire. The wiring length is controlled at 1200mm, the wire specification is 0.75mm², and a standard tubular lug is crimped.

[0044] The connection wire of the interlock relay 201 passes through the cable locking head on the axle box side plate, is laid along the fixed wire harness inside the wheel hub, and finally connects to the interlock terminal block 102 in the central control box. The 3, 5, 4, and 6 ports of the interlock relay 201 in the first axle box are connected to the 2C, 3C, 4C, and 5C ports of the interlock terminal block 102 respectively through black, yellow, green, and red wires. The second and third axle boxes are connected to the 3a, 5a, 6C, 1b, 2a, 4b, and 6a ports of the interlock terminal block 102 according to the same specifications. All axle box wiring follows the principle of one-to-one independent connection, without sharing circuits or cross wiring.

[0045] Remove the existing redundant wires inside the axle box, and bundle the new wires separately from the original wires. The wire laying path should avoid rotating parts, high-temperature areas and sharp edges to prevent wear and aging that could lead to failure. After the wiring is completed, use a multimeter to test the contact continuity and coil resistance to ensure that the interlock relay 201 operates normally.

[0046] In this embodiment, the input end of the signal feedback module 3 is directly connected to the feedback contact of the interlocking changeover switch 101 to obtain the mode switching signal. The output end wire passes through the spare channel of the slip ring into the nacelle and is connected to the digital input terminal of the unit PLC 7. In this embodiment, it is specifically connected to the 321DI5 port of the nacelle PLC. The wire specification is 0.75mm², the color is orange, the length is 1500mm, and the wire lug crimping standard is uniform.

[0047] The programmable DO output of the PMM logic control module 4 uses a one-to-one wiring method, connecting to the coils of three interlocking relays 201 respectively. In this embodiment, the PMM module X13:1 port is used first. If this port is occupied, it can be switched to the X13:2 port, while the wiring method and signal transmission logic remain unchanged. The PMM module is powered by the unit's existing 24VDC power supply, without adding a new independent power supply module, ensuring power supply stability. After wiring, check the output voltage of the DO port to ensure that the 24V output is normal and can reliably drive the interlocking relays 201 to operate.

[0048] Furthermore, the PMM logic control module 4 has a built-in configurable angle threshold parameter group, which includes the lower limit value of the blade angle, the upper limit value of the blade angle, and the interlock signal output mode configuration parameters. All parameters are configured through the windbench software. The windbench software is installed on the PC, and a CAN communication cable is used with a CAN-TO-USB converter card to achieve communication connection with the PMM module. After connection, the parameter configuration interface is entered, the original parameter file of the unit is modified, and interlock control related parameters are added.

[0049] In this embodiment, the core parameters are configured as follows: parameter 3220.0 is set to 3, representing the interlock function being enabled; parameter 3220.1 is set to 88.00, which is the lower limit of the blade angle; parameter 3220.2 is set to 100.00, which is the upper limit of the blade angle; parameter 3220.3 is set to 100, corresponding to the DO output port X13:1. If switching to the X13:2 port, parameter 3220.3 is modified to 200. All parameters are retained to two decimal places to ensure the accuracy of angle monitoring.

[0050] After parameter configuration, the parameter file and equipment firmware are updated synchronously. The PMM module firmware version needs to be updated to V3.12 to ensure firmware and parameter matching. The original control program of the unit is not interrupted during the update process; only the newly added interlock logic is enabled. The PMM logic control module 4 collects the three-axis blade angle signal in real time based on the angle threshold parameter group, continuously monitors the angle data and makes logical judgments. When the blade angle is within the range of 88.00°-100.00°, it is determined to be in a safe state, and a high-level signal is output to energize the interlock relay 201. When the blade angle exceeds this range, the output control signal is immediately stopped, and the interlock relay 201 is de-energized and disconnected, realizing automatic locking when the angle exceeds the limit.

[0051] After the parameters are configured, save the file and back it up. Each unit should save an independent copy of the parameters to facilitate later maintenance and troubleshooting. Different wind farm units can make minor adjustments to the lower and upper limits of the angle according to actual operation and maintenance needs. The output mode parameters should be modified according to the DO port used to ensure system compatibility.

[0052] A second aspect of the present invention provides a doubly-fed generator (DFG) OAT (Out-of-Attack) pitch blade interlock control method, wherein the method employs the doubly-fed generator (DFG) OAT pitch blade interlock control system as described above, and includes: Step 1: Switch the interlock switch of the central control interlock switching module to maintenance mode to keep the EFC emergency feathering signal circuit disconnected; For example, the interlock switch 101 of the central control interlock switching module 1 is switched from remote mode to maintenance mode. After the switch, the normally closed contact of the interlock switch 101 connected in series with the EFC emergency feathering signal circuit 5 is opened, keeping the EFC emergency feathering signal circuit 5 continuously open and preventing the emergency feathering action from being triggered during operation and maintenance, thus ensuring operation and maintenance safety from the hardware level. At the same time, the action of the feedback contact of the interlock switch 101 transmits the maintenance mode signal to the unit PLC7 through the slip ring backup channel via the signal feedback module 3, and the nacelle host computer displays the blade interlock maintenance mode activation status in real time.

[0053] Step 2: The PMM logic control module collects and monitors the angle information of the triaxial propeller blades in real time based on a preset angle threshold parameter group; For example, after the interlock mode is activated, the PMM logic control module 4 automatically starts the angle monitoring function. Based on the preset angle threshold parameter group, it collects the angle data of blades 1, 2, and 3 in real time. The collection frequency is consistent with the original angle collection frequency of the unit. After data collection, it performs filtering processing to remove interference signals and ensure the accuracy of angle determination. The PMM module continuously compares the real-time angle with the safe range of 88.00°-100.00° and performs logic determination without interruption.

[0054] Step 3: If any blade angle is within the safe range set by the angle threshold parameter group, the PMM logic control module outputs a control signal to energize the interlock relay of the corresponding shaft, thereby activating the PMC enable control loop of that shaft and allowing the blade to perform angle adjustment. For example, when the blade angle of any axis is within the safe range set by the angle threshold parameter group, the PMM logic control module 4 maintains the output of the programmable DO port, outputting a 24V high-level signal to energize and engage the interlock relay 201 of the corresponding axis. The control contact of the interlock relay 201 closes, thereby activating the PMC enable control circuit 6 of that axis. The PMC module receives the enable signal, allowing the blade to perform angle adjustment operations. Maintenance personnel can adjust the blade angle normally through modal switches. Modal switch 1 corresponds to a blade angle decreasing from large to small, and modal switch 2 corresponds to a blade angle increasing from small to large. During the adjustment process, the PMM module continuously monitors the angle to ensure that it is always within the safe range.

[0055] Step 4: If any blade angle exceeds the safe range, the PMM logic control module stops outputting control signals, causing the interlock relay of the corresponding shaft to de-energize and disconnect, thereby cutting off the PMC enable signal of that shaft and locking the blade position. The signal feedback module uploads the status signal of the interlock changeover switch to the unit PLC through the slip ring backup channel to achieve full-process interlock protection control.

[0056] For example, if the angle of any propeller blade exceeds the safe range during operation and maintenance, the PMM logic control module 4 immediately executes protection logic, stops the output of the programmable DO port, the interlock relay 201 of the corresponding axis de-energizes and disconnects, and the control contacts of the interlock relay 201 disconnect accordingly, thereby cutting off the PMC enable signal for that axis. After the PMC module loses the enable signal, it immediately stops the drive output, realizing the position locking of the corresponding propeller blade and preventing the propeller blade of that axis from continuing to rotate. This process is a hardware hard cutoff, which is not affected by software crashes or signal interference, and its reliability is higher than that of pure software limit switches. If the other two propeller blades are still within the safe range, they can be adjusted normally without interfering with each other.

[0057] Throughout the interlock protection process, the signal feedback module 3 continuously uploads the status signal of the interlock changeover switch 101 to the unit PLC7, enabling full-process status monitoring and recording. Maintenance personnel can view information such as the interlock mode, the status of each axis relay, and the real-time blade angle through the nacelle's host computer. After the maintenance work is completed, the maintenance personnel exit the hub and switch the interlock changeover switch 101 from maintenance mode back to remote mode. The EFC emergency feathering signal circuit 5 is restored to conduction, the interlock relay 201 returns to its initial state, and the PMC enable control circuit 6 restores its original control logic. The unit can then be put into normal operation. Upon exiting, it is confirmed that all three axis blades are at safe angles to avoid abnormal actions during mode switching.

[0058] This system is adaptable to MY1.5MW doubly-fed turbine units in different wind farms. Minor adjustments can be made based on site conditions without altering the core principles and structure. If port X13.1 of the PMM module is occupied, port X13.2 should be used instead, and parameter 3220.3 should be changed to 200 simultaneously. The cable locking head specification should be M16, M22, or M25 based on the shaft box opening and cable outer diameter, confirmed in advance through site survey. The installation position of the interlock terminal block 102 can be flexibly adjusted according to the space in the central control box. When the interlock changeover switch 101 interferes with other switches, its position can be interchanged with the emergency stop switch, and the panel label should be replaced simultaneously to ensure clear operation markings. The above are merely preferred embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A doubly-fed generator unit OAT (Output Adjustment and Activation) blade interlock control system, characterized in that, include: The central control interlock switching module is installed inside the pitch control box and includes an interlock changeover switch and an interlock terminal block. The normally closed contact of the interlock changeover switch is connected in series to the EFC emergency feathering signal circuit, and the signal terminal of the interlock changeover switch is electrically connected to the interlock terminal block. The three-axis interlocking actuator module is electrically connected to the interlocking terminal block. The three-axis interlocking actuator module includes three interlocking relays, which are respectively installed in the corresponding strain gauge propeller shaft box. The control contacts of the interlocking relays are connected in series to the PMC enable control circuit of the corresponding axis. The signal feedback module is also electrically connected to the interlock terminal block. One end of the signal feedback module is electrically connected to the interlock changeover switch, and the other end is electrically connected to the DI terminal of the unit PLC via the slip ring spare channel. The PMM logic control module has a programmable DO output terminal that is electrically connected to the coil of the interlock relay. It outputs control signals according to the blade angle range to drive the interlock relay to achieve triaxial blade interlock protection.

2. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, The interlocking changeover switch is located at the original lighting switch mounting position of the pitch control box; The other set of normally closed contacts of the interlock changeover switch is electrically connected at one end to the interlock terminal block and at the other end to the signal feedback module to form an interlock status feedback loop.

3. The doubly-fed generator OAT (Output Adjustment and Automated Guided Vehicle) blade interlock control system according to claim 1, characterized in that, The interlock terminal block is an independent wiring terminal block. The wiring terminals of the interlock terminal block are electrically connected one-to-one with the signal output terminal of the interlock changeover switch, the control terminals of the three interlock relays, and the input terminal of the signal feedback module, forming a multi-channel interlock wiring connection.

4. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, The side plate of the pitch shaft box has a mounting hole, and a cable locking head for sealing the cable insertion is fixedly installed at the mounting hole. The connection wire of the interlock relay is electrically connected to the interlock terminal via the cable locking head.

5. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, The interlocking relay is a DC 24V powered relay.

6. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, The PMM logic control module has a built-in configurable angle threshold parameter group, and the PMM logic control module outputs a corresponding control signal to the interlock relay based on the angle threshold parameter group.

7. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 6, characterized in that, The angle threshold parameter group includes the lower limit value of the blade angle, the upper limit value of the blade angle, and the interlock signal output mode configuration parameters.

8. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, The input terminal of the signal feedback module is electrically connected to the feedback contact of the interlock changeover switch, and the output terminal of the signal feedback module is electrically connected to the digital input terminal of the engine room PLC through the slip ring spare channel, which is used to transmit the status signal of the interlock changeover switch to the unit PLC.

9. The doubly-fed generator OAT (Out-of-Atmosphere) pitch blade interlock control system according to claim 1, characterized in that, When the angle of any propeller blade exceeds the set angle range, the PMM logic control module controls the interlock relay of the corresponding shaft to de-energize and disconnect, thereby cutting off the PMC enable signal of that shaft and thus locking the position of the corresponding propeller blade.

10. A doubly-fed generator unit OAT (Out-of-Atmosphere) pitch blade interlock control method, characterized in that, The method employs the doubly fed turbine OAT (Output Adjustment and Automated Guided Vehicle) blade interlock control system as described in any one of claims 1-9, and includes: Switch the interlock switch of the central control interlock switching module to maintenance mode so that the EFC emergency feathering signal circuit remains disconnected; The PMM logic control module collects and monitors the angle information of the triaxial propeller blades in real time based on a preset angle threshold parameter group. If any blade angle is within the safe range set by the angle threshold parameter group, the PMM logic control module outputs a control signal to energize the interlock relay of the corresponding shaft, thereby activating the PMC enable control loop of that shaft and allowing the blade to perform angle adjustment. If any blade angle exceeds the safe range, the PMM logic control module stops outputting control signals, causing the interlock relay of the corresponding shaft to de-energize and disconnect, thereby cutting off the PMC enable signal of that shaft and locking the blade position. The signal feedback module uploads the status signal of the interlock changeover switch to the unit PLC through the slip ring backup channel to achieve full-process interlock protection control.

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