Pitch control system and device

Abstract

The invention relates to a variable pitch control system and device. The system comprises a power grid, a blade lock, a driver and an interlocking module. A first interface of the driver is connected with the power grid, a second interface of the driver is connected with a first end of the interlocking module, a second end of the interlocking module is connected with the power grid, and a third end of the interlocking module is connected with the blade lock; the driver is used for receiving a locking instruction or an unlocking instruction and controlling the interlocking module to transmit currents of different phase sequences to the blade lock, and the blade lock is used for locking or unlocking the variable-pitch motor according to the received currents of different phase sequences, so that the safety of the wind turbine generator is improved.

Description

Technical Field

[0001] This disclosure relates to the field of wind turbine control technology, and more specifically, to a pitch control system and apparatus. Background Technology

[0002] The pitch control system is a device in wind turbines that controls the blades. It is mainly used to control the pitch angle of the wind turbine blades, thereby capturing wind energy and achieving air braking. Offshore wind turbines are affected by extreme weather, and the reliable locking of the pitch control system is the core guarantee for safe shutdown and operation and maintenance.

[0003] In existing technical solutions, the pitch control system typically controls the power supply and de-energization of the blade locks directly based on control commands issued by the wind turbine master controller. That is, after the wind turbine master controller issues a locking command, it supplies power to the blade lock, and the blade lock enters the locking hole. When the wind turbine master controller issues an unlocking command, it controls the blade lock to exit the locking hole. The control logic of this solution depends on the communication quality between the wind turbine master controller and the pitch control system, and is easily affected by electromagnetic interference, which may cause the locking or unlocking commands to be triggered erroneously. This results in the blade locks becoming stuck and unable to cope with the complex operating conditions of the wind turbine in harsh environments, seriously affecting the reliability and safety of the wind turbine. Summary of the Invention

[0004] The purpose of this disclosure is to provide a pitch control system and apparatus to improve the safety of wind turbine generators.

[0005] To achieve the above objectives, this disclosure provides a pitch control system, including: a power grid, a blade lock, a driver, and an interlock module; The first interface of the driver is connected to the power grid, the second interface of the driver is connected to the first end of the interlock module, the second end of the interlock module is connected to the power grid, and the third end of the interlock module is connected to the leaf lock. The driver is used to receive locking or unlocking commands and control the interlock module to transmit currents of different phase sequences to the blade lock. The blade lock is used to lock or unlock the pitch motor according to the received currents of different phase sequences.

[0006] Optionally, the interlock module includes a first power supply, a first input terminal of which is connected to the neutral line interface of the power grid, and a second input terminal of which is connected to at least one phase of the three-phase power supply interface of the power grid.

[0007] Optionally, the interlock module includes a first relay, a second relay, a first contactor, and a second contactor. The driver further includes a third interface. The second interface of the driver includes a first pin and a second pin. The first pin is used to output current when the locking command is received, and the second pin is used to output current when the unlocking command is received. The first pin of the driver is connected to the first end of the coil of the first relay, the second pin of the driver is connected to the first end of the coil of the second relay, and the second end of the coil of the first relay and the second end of the coil of the second relay are connected together to the third interface of the driver. The first input terminal of the first power supply is connected to the neutral line interface of the power grid, the second input terminal of the first power supply is connected to at least one phase of the three-phase power supply interface of the power grid, and the first terminal of the normally open contact switch of the first relay and the first terminal of the normally open contact switch of the second relay are connected together to the positive output terminal of the first power supply. The second terminal of the normally open contact switch of the first relay is connected to the first terminal of the normally closed contact switch of the second contactor, and the second terminal of the normally closed contact switch of the second contactor is connected to the first terminal of the coil of the first contactor. The second terminal of the normally open contact switch of the second relay is connected to the first terminal of the normally closed contact switch of the first contactor, and the second terminal of the normally closed contact switch of the first contactor is connected to the first terminal of the coil of the second contactor. The second end of the coil of the first contactor and the second end of the coil of the second contactor are connected together and then connected to the negative output terminal of the first power supply; The first terminal of the normally open contact switch of the first contactor is connected to the three-phase power interface of the power grid, and the first terminal of the normally open contact switch of the second contactor is connected to the three-phase power interface of the power grid. The second terminal of the normally open contact switch of the first contactor and the second terminal of the normally open contact switch of the second contactor are respectively connected to the input terminal of the leaf lock.

[0008] Optionally, the three-phase power supply interface of the power grid includes a first-phase interface, a second-phase interface, and a third-phase interface; The first interface of the normally open contact switch of the first contactor is connected to the first phase interface, the second interface of the normally open contact switch of the first contactor is connected to the second phase interface, and the third interface of the normally open contact switch of the first contactor is connected to the third phase interface. The first interface of the normally open contact switch of the second contactor is connected to the first phase interface, the second interface of the normally open contact switch of the second contactor is connected to the third phase interface, and the third interface of the normally open contact switch of the second contactor is connected to the second phase interface. The normally open contact switch of the first contactor is used to convert the three-phase AC power output from the power grid into the phase sequence corresponding to the locking command, and the normally open contact switch of the second contactor is used to convert the three-phase AC power output from the power grid into the phase sequence corresponding to the unlocking command.

[0009] Optionally, the interlock module further includes a third relay and a fourth relay, the input terminal of the leaf lock includes a first input interface and a second input interface, the output terminal of the leaf lock includes a first output interface and a second output interface, and the driver further includes a fourth interface; The second terminals of the normally open contact switches of the first contactor and the second contactor are connected together and then connected to the first input interface of the leaf lock. The second input interface of the leaf lock is connected to the positive output terminal of the first power supply. The first output terminal of the leaf lock is connected to the first terminal of the coil of the third relay, the second output terminal of the leaf lock is connected to the first terminal of the coil of the fourth relay, and the second terminals of the coils of the third relay and the fourth relay are connected together and then connected to the negative output terminal of the first power supply. The first terminal of the normally open contact switch of the third relay is connected to the first pin of the fourth interface, and the first terminal of the normally open contact switch of the fourth relay is connected to the second pin of the fourth interface. The second terminals of the normally open outgoing contact switches of the third relay and the fourth relay are connected together and then connected to the third pin of the second interface of the driver. The third pin of the second interface is the power supply pin. The fourth interface of the driver is used to determine the locking state of the pitch motor based on the electrical signal output by the blade lock.

[0010] Optionally, the system further includes a current transformer; The current acquisition unit of the current transformer is connected in series with at least one phase of the connection line between the first input interface of the leaf lock and the first contactor and the second contactor; The first end of the current transformer is connected to the positive output terminal of the first power supply, the second end of the current transformer is grounded, and the third end of the current transformer is connected to the fourth pin of the second interface of the driver. The fourth pin of the second interface of the driver is used to determine the fault condition of the pitch motor based on the received electrical signal.

[0011] Optionally, the system also includes a motor protector; The first contactor and the second contactor are connected to the three-phase power interface of the power grid through the motor protector, which is used to provide overcurrent protection for the first contactor, the second contactor, and the leaf lock.

[0012] Optionally, the system further includes a first surge protector, a second surge protector, a third surge protector, a fourth surge protector, a first air switch, a second air switch, and a load switch; The input terminal of the load switch is connected to the power grid, and the output terminal of the load switch is connected to the input terminal of the first air switch. The output terminal of the first air switch is connected to the input terminal of the motor protector, the input terminal of the first power supply, and the first interface of the driver, respectively. The second input terminal of the first power supply is connected to the output terminal of at least one corresponding first air switch in the three-phase power interface of the power grid through the second air switch. The first surge protector is connected between the power grid and the load switch, and the first surge protector is used for; The third terminal of the current transformer is connected to the fourth pin of the second interface of the driver through the second surge protector; The coils of the first relay and the second relay are connected to the third interface of the driver through the third surge protector; The first power supply is connected to the leaf lock, the normally open contact switch of the first relay, and the normally open contact switch of the second relay through the fourth surge protector; The first surge protector, the second surge protector, the third surge protector, and the fourth surge protector are all used for overcurrent protection. The load switch is used to control the power supply to the pitch control system. The first air switch is used to provide short-circuit protection for the blade lock, and the second air switch is used to provide short-circuit protection for the first power supply.

[0013] Optionally, the driver further includes a fifth interface and a sixth interface, and the first interface of the driver includes an input pin and an output pin; The input pin of the first interface of the driver is connected to the power grid, the output pin of the first interface of the driver is connected to the motor, and the output pin of the first interface of the driver is used to supply power to the pitch motor. The fifth interface of the driver is connected to the pitch motor, and the fifth interface is used to control the speed of the pitch motor; The sixth interface of the driver is connected to the pitch motor. The sixth interface is used to collect the current and blade angle of the pitch motor. The driver is also used to generate the locking command and the unlocking command based on the current and blade angle collected by the sixth interface.

[0014] This disclosure also provides a pitch control device, which includes the pitch control system provided in this disclosure.

[0015] Through the above technical solution, the driver controls the interlock module to output only the phase sequence current corresponding to the command, avoiding circuit faults caused by command conflicts. The blade lock is connected to the power grid through the interlock module, enabling the blade lock to perform unlocking or locking actions according to the phase sequence difference, avoiding motor blade jamming, improving the reliability of pitch motor locking and unlocking, and thus improving the safety and stability of the wind turbine.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a pitch control system according to an exemplary embodiment.

[0018] Figure 2 This is a schematic diagram of a leaf lock according to an exemplary embodiment.

[0019] Figure 3 This is a schematic diagram of a pitch control system according to an exemplary embodiment.

[0020] Figure 4 This is a flowchart illustrating a pitch control method according to an exemplary embodiment. Detailed Implementation

[0021] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0022] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0023] It should be noted that all actions involving the acquisition of signals, information, or data in this disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the location is situated, and with authorization from the owner of the relevant device.

[0024] In the following description, the words "first" and "second" are used only to distinguish the purpose of the description and should not be interpreted as indicating or implying relative importance or order.

[0025] Figure 1This is a schematic diagram of a pitch control system according to an exemplary embodiment. See also: Figure 1 As shown, the system includes: power grid M, blade lock BL, driver P6, and interlock module LK.

[0026] The first interface X1 of the driver P6 is connected to the power grid M, the second interface X10 of the driver P6 is connected to the first end of the interlock module LK, the second end of the interlock module LK is connected to the power grid M, and the third end of the interlock module LK is connected to the blade lock BL. The driver P6 is used to receive locking or unlocking commands and control the interlock module LK to transmit currents of different phase sequences to the blade lock. The blade lock BL is used to lock or unlock the pitch motor according to the received currents of different phase sequences.

[0027] It is worth noting that the locking or unlocking commands received by the drive P6 may be issued by the wind turbine main control, manually input, or automatically generated by the drive P6 based on the operating status of the pitch motor. A schematic diagram of the blade lock is shown below. Figure 2 As shown, when the blade lock enters the lock hole, the pitch motor is locked; when the blade lock exits the lock hole, the pitch motor is unlocked.

[0028] In one embodiment, the interlock module LK includes a first circuit and a second circuit. When the first circuit is active, the power grid M transmits an electrical signal of the first phase sequence to the blade lock through the first circuit, causing the blade lock BL to lock the pitch motor and the second circuit to be locked, thus preventing the unlocking action from being performed during the locking of the pitch motor. When the second circuit is active, the power grid M transmits an electrical signal of the second phase sequence to the blade lock through the second circuit, causing the blade lock BL to unlock the pitch motor and the first circuit to be locked, thus preventing the locking action from being performed during the unlocking of the pitch motor, thereby avoiding circuit conflicts caused by accidental triggering of locking and unlocking commands due to electromagnetic interference or other reasons.

[0029] Through the above technical solution, the driver controls the interlock module to output only the phase sequence current corresponding to the command, avoiding circuit faults caused by command conflicts. The blade lock is connected to the power grid through the interlock module, enabling the blade lock to perform unlocking or locking actions according to the phase sequence difference, avoiding motor blade jamming, improving the reliability of pitch motor locking and unlocking, and thus improving the safety and stability of the wind turbine.

[0030] Figure 3 This is a schematic diagram of a pitch control system according to an exemplary embodiment. See also: Figure 3 As shown, the power grid M includes three-phase power interfaces (L1, L2, L3), a center line interface N, and a ground line interface PE.

[0031] In one optional implementation, the interlock module LK includes a first power supply m, the first input terminal N of the first power supply m is connected to the neutral line interface N of the power grid M, and the second input terminal L of the first power supply m is connected to at least one of the three-phase power supply interfaces (L1, L2, L3) of the power grid M.

[0032] Among them, the power grid M is a 400V heavy-duty three-phase main power supply, providing power to high-power actuators such as the pitch motor and blade lock BL, adapting to the high-power drive requirements of wind power systems; at the same time, it provides a single-phase input to the first power supply m of the interlock module LK, ensuring the power supply source for the control circuit. Figure 3 The L terminal of the first power source m shown is connected to the L1 interface of the power grid. It is easy to understand that the L terminal of the first power source m is also connected to L2 and L3 in the same way as the L1 case, and this disclosure will not elaborate on this.

[0033] The first power supply m is a control-level power conversion unit (such as an AC / DC power module). Its function is to convert one phase of the three-phase main power from the power grid into the adaptive control power (such as 24V DC) required by the interlocking module, providing drive power for the contactor coils, relays, and other actuators inside the interlocking module. The first input terminal N (connected to the power grid N) serves as the negative circuit for the power input, sharing a common ground with the power grid neutral line to ensure voltage stability during power conversion. The second input terminal L (connected to any phase of the power grid L1 / L2 / L3) obtains single-phase AC power as the energy input for power conversion, realizing the step-down and rectification conversion of the main power to the control power.

[0034] Through the interface configuration via the power grid M, it provides high-power main power to meet the power requirements of the actuators, and balances the load through the N line and ensures safety through the PE line, laying a stable power supply foundation for the system. The overall architecture, through the design of three-phase main power supply, independent control power conversion, and safety ground wire protection, takes into account the high power requirements of the wind power system, the control stability in complex electromagnetic environments, and the safety requirements of outdoor operations, ensuring that the system can still operate reliably under conditions such as vibration and voltage fluctuations.

[0035] Optionally, see [link to relevant documentation] Figure 3 As shown, driver P6 includes a first interface X1, a second interface X10, a third interface X8, a fourth interface X9, a fifth interface X2, and a sixth interface X3.

[0036] Among them, the pins L1, L2, and L3 of the first interface X1 are connected to the power grid M to supply power to the loads such as the driver P6, blade lock BL, and pitch motor; the pins U, V, and W of the first interface X1 are connected to the pitch motor to output a three-phase frequency converter power supply, which directly drives the pitch motor MT to operate and controls the pitch action of the blades.

[0037] The AI1+ and GND pins of the second interface X10 are connected to the signal of the current transformer T1 transmitted through the second surge protector LP1. This signal is used to collect the operating current of the leaf lock and monitor whether the lock action is stuck or overloaded. The 24V+ pin of the second interface X10 is usually the 24V power output / input terminal of P6, which provides 24V power to external digital components (such as relays and sensors) or serves as a signal reference. The DO1 / DO2 pins of the second interface X10 are digital output interfaces, which are used to output switch signals to control the coils of the first relay K1 and the second relay K2 respectively, thereby triggering the locking or unlocking action of the leaf lock BL (DO1 corresponds to locking, DO2 corresponds to unlocking).

[0038] The COM pin of the third interface X8 is the common reference terminal (i.e., the negative terminal of the signal loop) of the DO1 and DO2 output circuits, which, together with DO1 / DO2, form the control loop of the first relay K1 and the second relay K2.

[0039] Pins DI1 and DI2 of the fourth interface X9 are connected to the contact signals of the third relay K3 and the fourth relay K4, respectively, to provide feedback on the actual status of the leaf lock BL (e.g., locked / unlocked / in progress); pin DI3 of the fourth interface X9 is connected to the contact signal of the motor protector MP1 to provide feedback on the overcurrent status of the 400V power supply circuit (DI3 is high level under normal conditions and low level under overcurrent conditions); pin DI4 of the fourth interface X9 is connected to the contact signal of the first surge protector LP0 to provide feedback on lightning strike faults on the power grid side (DI4 is high level under normal conditions and low level under failure conditions).

[0040] The fifth interface X2 pins B+ / B- are the braking unit interface, which is used to connect an external braking resistor or braking unit to consume the regenerative energy generated when the pitch motor decelerates, and to prevent the internal bus voltage of P6 from being too high (to avoid driver failure).

[0041] Pins T1 / T2 of the sixth interface X3 are connected to a temperature sensor (such as a motor winding temperature sensor) to monitor the temperature of the pitch motor MT or the driver P6, thus achieving overheat protection. Pins PT1+ / PT1- of the sixth interface X3 are connected to the resolver signal built into the pitch motor MT to acquire the position of the motor rotor (i.e., the real-time angle of the blades), providing position feedback for pitch control.

[0042] In one embodiment, the interlock module LK includes a first relay K1, a second relay K2, a first contactor M1, and a second contactor M2. The driver P6 also includes a third interface X8. The second interface X10 of the driver P6 includes a first pin DO1 and a second pin DO2. The first pin DO1 is used to output current when a lock command is received, and the second pin DO2 is used to output current when an unlock command is received.

[0043] The first pin DO1 of the driver P6 is connected to the first end of the coil of the first relay K1, and the second pin DO2 of the driver P6 is connected to the first end of the coil of the second relay K2. The second end of the coil of the first relay K1 and the second end of the coil of the second relay K2 are connected together and then connected to the third interface X8 of the driver P6.

[0044] The first input terminal N of the first power supply m is connected to the neutral line interface of the power grid M. The second input terminal L of the first power supply m is connected to at least one phase of the three-phase power supply interface of the power grid M. The first terminal of the normally open contact switch of the first relay K1 and the first terminal of the normally open contact switch of the second relay K2 are connected together to the positive output terminal of the first power supply m.

[0045] The second terminal of the normally open contact switch of the first relay K1 is connected to the first terminal of the normally closed contact switch of the second contactor M2, and the second terminal of the normally closed contact switch of the second contactor M2 is connected to the first terminal of the coil of the first contactor M1.

[0046] The second terminal of the normally open contact switch of the second relay K2 is connected to the first terminal of the normally closed contact switch of the first contactor M1, and the second terminal of the normally closed contact switch of the first contactor M1 is connected to the first terminal of the coil of the second contactor M2.

[0047] The second end of the coil of the first contactor M1 and the second end of the coil of the second contactor M2 are connected together and then connected to the negative output terminal of the first power supply m.

[0048] The first terminal of the normally open contact switch of the first contactor M1 is connected to the three-phase power interface of the power grid M, and the first terminal of the normally open contact switch of the second contactor M2 is connected to the three-phase power interface of the power grid M.

[0049] The second terminal of the normally open contact switch of the first contactor M1 and the second terminal of the normally open contact switch of the second contactor M2 are respectively connected to the input terminal of the leaf lock BL.

[0050] In one implementation, assuming the pitch control system needs to perform a pitch motor MT locking action, and the current system state is: the power grid M is supplying power normally (L1 / L2 / L3 three-phase energized, N line and PE line normally grounded), the first power supply m has completed conversion and outputs 24V DC control power, and when the driver P6 does not receive any command, the K1 and K2 coils are de-energized (normally open contacts open), the M1 and M2 coils are de-energized (normally open contacts open, normally closed contacts remain conducting), and the blade lock BL is in the unlocked state. The specific locking process is as follows: The main controller of the wind turbine sends a locking command to the driver P6. After internal logic verification (e.g., the blade angle is within ±3° of the stopping angle, and there are no conflicting commands), P6 outputs 24V DC current from the first pin DO1 of its second interface X10, forming a drive circuit: pin DO1 of P6's second interface → K1 coil → P6's third interface X8 (common terminal). The K1 coil is energized, generating electromagnetic attraction. After the K1 coil is energized, its normally open contact switch changes from the open state to the closed state, and the 24V control current is transmitted to the subsequent circuit through this contact: positive terminal of the first power supply m → K1 normally open contact → subsequent contactor control circuit. Since the M2 coil is currently de-energized, its normally closed contact switch remains conducting. The 24V control current passes through the M2 normally closed contact switch → M1 coil and the negative terminal of the first power supply m are connected together, forming a complete circuit, and the M1 coil is energized. After the M1 coil is energized, two sets of actions are triggered simultaneously: First, the normally closed contact switch of M1 switches from the conducting state to the open state, cutting off the control circuit between the second relay K2 and the M2 coil (even if DO2 is output incorrectly later, the M2 coil cannot be energized); second, the normally open contact switch of M1 (main circuit side) switches from the open state to the closed state, connecting the power supply circuit between the grid M and the blade lock BL. After the normally open contact of M1 closes, the three-phase current of the grid M is transmitted to the blade lock BL according to the locking phase sequence (such as L1→U phase, L2→V phase, L3→W phase). The internal actuator of the blade lock (such as the electromagnetic lock core and drive motor) moves towards the transmission components of the pitch motor (such as the hub gear ring) and mechanically engages under the drive of the phase sequence current, finally completing the locking action of the pitch motor. After the blade lock BL is locked, its internal position detection element is triggered and fed back to the DI1 / DI2 interface of P6 through signal 1 and signal 2 (both are at low level). After P6 confirms that the locking is successful, it disconnects the DO1 output, the K1 coil is de-energized (normally open contact opens), the M1 coil is de-energized (normally open contact opens, normally closed contact resumes conduction), the locking process ends, and the system maintains the mechanical locking state of the blade lock.

[0051] In another implementation, assuming the pitch control system needs to perform a pitch motor unlocking action, the current system state is: the power grid and the first power source m are supplying power normally, the blade lock BL is in a locked state, coils K1 and K2 are de-energized, and coils M1 and M2 are de-energized (normally closed contact switches are open). The specific unlocking process is as follows: The main controller of the wind turbine sends an unlock command to the driver P6. After logic verification (e.g., no locking command conflict, no system fault alarm), P6 outputs 24V DC current from the second pin DO2 of its second interface X10, forming a drive circuit: P6DO2 → K2 coil A1 → K2 coil A2 → P6 third interface X8. The K2 coil is energized, generating electromagnetic attraction. Relay contact operation: After the K2 coil is energized, its normally open contact switch changes from open to closed. The 24V control current transmission path is: positive terminal of the first power supply m → normally open contact switch of K2 → subsequent contactor control circuit. Since the M1 coil is currently de-energized, its normally closed contact switch remains conducting. The 24V control current passes through the normally closed contact switch of M1 → the M2 coil is connected to the negative terminal of the first power supply m, forming a complete circuit, and the M2 coil is energized. After the coil of M2 is energized, two sets of actions are triggered simultaneously: First, the normally closed contact switch of M2 switches from the conducting state to the open state, cutting off the control circuit between the first relay K1 and the coil of M1 (to prevent DO1 from being erroneously output and causing M1 to be energized); second, the normally open contact switch of M2 (main circuit side) switches from the open state to the closed state, connecting the power supply circuit between the power grid M and the blade lock BL. After the normally open contact switch of M2 closes, the three-phase current of the power grid M is transmitted to the blade lock BL according to the unlocking phase sequence (such as L1→V phase, L2→U phase, L3→W phase, which is the opposite of the locking phase sequence). Under the drive of the reverse phase sequence current, the internal actuator of the blade lock releases the mechanical engagement with the pitch motor drive components, completing the unlocking action of the pitch motor MT. After the blade lock BL is unlocked, the internal position detection element is triggered, and both DI1 / DI2 interfaces are at a high level. After P6 confirms successful unlocking, the DO2 output is disconnected, the K2 coil is de-energized (normally open contact opens), the M2 coil is de-energized (normally open contact opens, normally closed contact resumes conduction), the unlocking process ends, and the pitch motor can drive the blade pitch normally.

[0052] If electromagnetic interference or mis-issued commands cause the driver P6 to simultaneously output DO1 (lock) and DO2 (unlock) signals, the hardware interlock logic of the interlock module LK will quickly take effect: Assuming that coils K1 and K2 are energized simultaneously, their normally open contacts will both close; if coil M1 is energized first, the normally closed contact of M1 will open, cutting off the circuit of coil M2, and M2 will not be energized; if coil M2 is energized first, the normally closed contact of M2 will open, cutting off the circuit of coil M1, and M1 will not be energized; ultimately, only the contactor that conducts first will operate, avoiding simultaneous engagement of M1 and M2 that could lead to phase sequence misconnection, thus physically preventing blade lock jamming, coil burnout, and other faults, adapting to the reliability requirements of complex wind power operating conditions.

[0053] Optionally, the three-phase power supply interface of the power grid M includes a first-phase interface L1, a second-phase interface L2, and a third-phase interface L3.

[0054] The first interface of the normally open contact switch of the first contactor M1 is connected to the first phase interface L1, the second interface of the normally open contact switch of the first contactor M1 is connected to the second phase interface L2, and the third interface of the normally open contact switch of the first contactor M1 is connected to the third phase interface L3.

[0055] The first interface of the normally open contact switch of the second contactor M2 is connected to the first phase interface L1, the second interface of the normally open contact switch of the second contactor M2 is connected to the third phase interface L3, and the third interface of the normally open contact switch of the second contactor M2 is connected to the second phase interface L2.

[0056] The normally open contact switch of the first contactor M1 is used to convert the three-phase AC power output from the power grid M into the phase sequence of the corresponding locking command, and the normally open contact switch of the second contactor M2 is used to convert the three-phase AC power output from the power grid M into the phase sequence of the corresponding unlocking command.

[0057] For example, the first contactor M1 maintains a locked phase sequence outputting the phase sequence "L1→U phase, L2→V phase, L3→W phase" to the leaf lock BL to drive the leaf lock to perform a locking action, while the second contactor M2 maintains an unlocked phase sequence outputting the phase sequence "L1→U phase, L3→V phase, L2→W phase in reverse" to the leaf lock BL to drive the leaf lock to perform an unlocking action.

[0058] The LK interlock module achieves M1 conduction corresponding to the original phase sequence (locking) and M2 conduction corresponding to the reverse phase sequence (unlocking) through the differentiated phase sequence wiring of M1 and M2 and the hardware interlock design of cross normally closed contacts. The hardware interlock ensures that the two cannot conduct at the same time, which not only guarantees the accuracy of the locking / unlocking action, but also avoids the risk of phase sequence conflict under abnormal operating conditions from a physical perspective.

[0059] In one implementation, see Figure 3 As shown, the interlock module LK also includes a third relay K3 and a fourth relay K4. The input terminals of the blade lock BL include a first input interface and a second input interface. The output terminals of the blade lock BL include a first output interface and a second output interface. The driver P6 also includes a fourth interface X9.

[0060] The first input interface of the vane lock BL is a three-phase power input interface, the second input interface of the vane lock BL is a 24V power input interface, and the first output interface of the vane lock BL is as follows: Figure 3 The signal 1 output interface shown is the second output interface of the leaf lock BL. Figure 3 The signal output interface 2 is shown.

[0061] For example, when signal 1 is output (corresponding to K3 coil being energized and DI1 being high), it indicates that the mechanical actuator of the leaf lock is still in operation (not fully locked). At this time, the driver P6 will continue to execute the following steps: First, continuously monitor the lock status and current: The driver monitors the status of signal 1 and signal 2 through DI1 / DI2, and at the same time monitors the leaf lock current collected by the current transformer T1 through the AI ​​interface (to confirm that the lock action is not stuck).

[0062] Then, maintain the lock power supply until completion: keep DO1 output (K1 is engaged, M1 contactor is on), and continuously supply 400V lock phase sequence power to the blade lock until the blade lock is fully locked (signal 1 and signal 2 are both off, DI1 / DI2 are both low level).

[0063] Secondly, the blade lock mechanically locks the blade: After the blade lock is fully locked, its internal mechanical structure will engage with the transmission component (or hub) of the blade to fix the position of the blade.

[0064] Furthermore, the pitch motor is locked along with the blade: the pitch motor MT and the blade are mechanically rigidly connected (the motor shaft directly drives the blade to change pitch), so after the blade is locked by the blade lock, the shaft of the pitch motor cannot rotate, which is equivalent to locking the pitch motor.

[0065] Finally, the driver will disconnect the DO1 output, the M1 contactor will lose power, and the power supply to the blade lock will stop. The blade lock will remain in a mechanically locked state, and the pitch motor will also remain in a locked state.

[0066] In one embodiment, the second terminals of the normally open contact switches of the first contactor M1 and the second contactor M2 are connected together and then connected to the first input interface of the leaf lock BL. The second input interface of the leaf lock BL is connected to the positive output terminal of the first power supply m.

[0067] The first output terminal of the leaf lock BL is connected to the first terminal of the coil of the third relay K3, and the second output terminal of the leaf lock BL is connected to the first terminal of the coil of the fourth relay K4. The second terminals of the coils of the third relay K3 and the fourth relay K4 are connected together and then connected to the negative output terminal of the first power supply m.

[0068] The first terminal of the normally open contact switch of the third relay K3 is connected to the first pin D11 of the fourth interface X9, and the first terminal of the normally open contact switch of the fourth relay K4 is connected to the second pin D12 of the fourth interface X9.

[0069] The second terminals of the normally open outgoing contact switches of the third relay K3 and the fourth relay K4 are connected together and then connected to the third pin (24V) of the second interface X10 of the driver P6. The third pin of the second interface X10 is the power supply pin.

[0070] Among them, the fourth interface X9 of the driver P6 is used to determine the locking state of the pitch motor MT based on the electrical signal output by the blade lock BL.

[0071] It is worth noting that the operation (locking / unlocking) of the vane lock is controlled by the phase sequence of the three-phase power supply: the pitch system switches the phase sequence of the 400V power supply via contactors M1 and M2 (M1 energizing corresponds to the "locking phase sequence," and M2 energizing corresponds to the "unlocking phase sequence"), driving the internal actuators of the vane lock (such as the electromagnetic lock cylinder and a small drive motor) to complete the mechanical locking / unlocking action; the vane lock integrates position detection elements (such as limit switches and proximity switches) to monitor the actual state of the lock and provides feedback externally through "Signal 1" and "Signal 2." The timing of the output of Signal 1 and Signal 2 is determined by the actual state of the vane lock (corresponding to the on / off state of the internal position detection elements): When the blade lock is in the unlocked state: both internal position detection elements are triggered, and signals 1 and 2 are simultaneously turned on (at this time, coils K3 and K4 are energized, and DI1 and DI2 of pitch driver P6 are both high level); when the blade lock is in the locking process: only one position detection element is triggered (the other is not yet in position), and only one of signals 1 and 2 is turned on (at this time, only one of K3 / K4 is engaged, and DI1 / DI2 is one high and one low); when the blade lock is in the locked state: neither internal position detection element is triggered, and signals 1 and 2 are both turned off (at this time, K3 and K4 are de-energized, and DI1 and DI2 are both low level).

[0072] For example, the locked or unlocked state of the leaf lock BL is fed back to the driver P6 via the third relay K3 and the fourth relay K4. Signal 1 of the leaf lock BL controls the coil of K3, and signal 2 controls the coil of K4. The normally open contact switch of K3 is connected to 24V+ and DI1, and the normally open contact switch of K4 is connected to 24V+ and DI2. If both DI1 and DI2 are low, it means that neither K3 nor K4 is engaged, and the leaf lock is locked. If one of DI1 and DI2 is high and the other is low, it means that one of K3 and K4 is engaged, and the leaf lock is in the locking process. If both DI1 and DI2 are high, it means that both K3 and K4 are engaged, and the leaf lock is in the unlocked state.

[0073] In one implementation, see Figure 3 As shown, the system also includes a current transformer T1.

[0074] The current collector of current transformer T1 is connected in series with at least one phase of the connection line between the first input interface of leaf lock BL and the first contactor M1 and the second contactor M2.

[0075] The first terminal 1 of the current transformer T1 is connected to the positive output terminal of the first power supply m. The second terminal 4 of the current transformer T1 is grounded. The third terminal 2 of the current transformer T1 is connected to the fourth pin AI1+ of the second interface X10 of the driver P6. The fourth pin of the second interface of the driver P6 is used to determine the fault condition of the pitch motor MT based on the received electrical signal.

[0076] For example, the following scenarios exist during the locking process of a pitch motor: Scenario 1 (Normal Locking Scenario): P6 receives the locking command → DO1 outputs → K1 is energized → M1 coil conducts (hardware interlock cuts off M2 circuit) → M1 normally open contact closes, and the original phase sequence of the power grid L1 / L2 / L3 is transmitted to the blade lock; the blade lock is energized and starts, T1 collects the W phase current (from the starting current of 7A to the stable current of 5A), and outputs the corresponding analog signal (e.g., 20mA at startup, 16mA at stability) to AI1+ of P6 through the third terminal 2; P6 analyzes the current signal: confirms that the current is within the threshold range and the trend is normal, determines that the blade lock is operating normally, and after DI1 / DI2 feedback that the lock is in place (both are low level), DO1 is disconnected, and the locking process is completed.

[0077] Scenario 2 (Abnormal Fault Scenario - Leaf Lock Jamming): If the leaf lock is mechanically jammed (the locking tongue cannot extend), the current will remain at 8.5A after startup (exceeding the jamming threshold), and the analog signal output by T1 will always remain at 22mA (exceeding the range). P6 will monitor the current exceeding the standard in real time and the duration will reach 100ms, and immediately trigger the protection logic: First, disconnect the DO1 output, K1 loses power → M1 coil loses power, the main circuit is disconnected, and power supply to the leaf lock will stop; Second, report "Leaf lock jamming fault" and prohibit the execution of subsequent control commands; Third, maintain the hardware interlock state to avoid accidental triggering of unlocking commands.

[0078] Scenario 3 (Abnormal Fault Scenario - Leaf Lock Not Operated): If the M1 contact is stuck or the main circuit is disconnected, the leaf lock is not energized, T1 collects the current as 0, and outputs an analog signal of 4mA (lower limit); P6 detects that the current is 0 and lasts for 500ms (exceeding the normal startup time), determines "locking action not executed fault", disconnects DO1 and alarms, prompting maintenance personnel to check the main circuit or contactor fault.

[0079] In one embodiment, the system also includes a motor protector MP1.

[0080] The first contactor M1 and the second contactor M2 are connected to the three-phase power interface of the power grid M through the motor protector MP1. The motor protector MP1 is used to provide overcurrent protection for the first contactor M1, the second contactor M2 and the leaf lock BL.

[0081] The above methods improve the stability of the pitch control system during locking and unlocking, thereby enhancing the safety of the wind turbine.

[0082] In one embodiment, see Figure 3 As shown, the system also includes a first surge protector LP0, a second surge protector LP1, a third surge protector LP2, a fourth surge protector LP4, a first air switch F1, a second air switch F2, and a load switch Q1.

[0083] The input terminal of the load switch Q1 is connected to the power grid M, and the output terminal of the load switch Q1 is connected to the input terminal of the first air switch F1. The output terminal of the first air switch F1 is connected to the input terminal of the motor protector MP1, the input terminal of the first power supply m, and the first interface of the driver P6. The second input terminal L of the first power supply m is connected to the output terminal of at least one corresponding first air switch F1 in the three-phase power interface of the power grid M through the second air switch F2.

[0084] The first surge protector LP0 is connected between the power grid M and the load switch Q1. The first surge protector MP0 is used for...

[0085] The third terminal 2 of the current transformer T1 is connected to the fourth pin AI1+ of the second interface X10 of the driver P6 through the second surge protector LP1.

[0086] The coils of the first relay K1 and the second relay K2 are connected to the third interface X8 of the driver P6 through the third surge protector LP2.

[0087] The first power supply m is connected to the leaf lock BL, the normally open contact switch of the first relay K1, and the normally open contact switch of the second relay K2 via the fourth surge protector LP3.

[0088] Among them, the first surge protector LP0, the second surge protector LP1, the third surge protector LP2 and the fourth surge protector LP4 are all used for overcurrent protection, the load switch Q1 is used to control the power supply of the pitch control system, the first air switch F1 is used to provide short-circuit protection for the blade lock BL, and the second air switch F2 is used to provide short-circuit protection for the first power supply m.

[0089] The above methods improve the stability of the pitch control system during locking and unlocking, thereby enhancing the safety of the wind turbine.

[0090] In one embodiment, see Figure 3 As shown, the driver P6 also includes a fifth interface X2 and a sixth interface X3. The first interface of the driver P6 includes input pins and output pins.

[0091] The input pin of the first interface of the driver P6 is connected to the power grid M, the output pin of the first interface of the driver P6 is connected to the pitch motor MT, and the output pin of the first interface of the driver P6 is used to supply power to the pitch motor MT.

[0092] The fifth interface X2 of the driver P6 is connected to the pitch motor MT, and the fifth interface X2 is used to control the speed of the pitch motor MT.

[0093] The sixth interface X3 of the driver P6 is connected to the pitch motor MT. The sixth interface X3 is used to collect the current and blade angle of the pitch motor MT. The driver P6 is also used to generate lock and unlock commands based on the current and blade angle collected by the sixth interface.

[0094] The above methods improve the stability of the pitch control system during locking and unlocking, thereby enhancing the safety of the wind turbine.

[0095] This disclosure also provides a pitch control device, which includes the pitch control system provided above.

[0096] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0097] Furthermore, this disclosure also provides a pitch control method, wherein a pitch application program is stored in the driver P6 to execute the pitch control method provided in this disclosure. See [link to relevant documentation]. Figure 4 As shown, the method includes the following steps: The first step is to perform fault detection on the contact switch status of the first surge protector LP0 (i.e., the 400V surge protector LP0).

[0098] If the LP0 contact is normal, proceed to the next step. If the LP0 contact switch is abnormal, that is, when the normally open contact switch of the first surge protector LP0 is detected to be open, i.e., at a low level, report a surge protector LP0 fault.

[0099] The second step is to detect the blade angle in real time.

[0100] If the blade angle is within the preset range of the stopping angle (e.g., ±3 degrees), proceed to the next step. If it is outside the preset range, do not execute the blade lock control command, and continue to detect the blade angle range.

[0101] The third step is to wait for and receive the wind turbine main control blade lock control command.

[0102] When both the blade lock control locking command and the unlock command are present, the blade lock control command is not executed, and the system continues to wait for the wind turbine main control blade lock control command; when the locking command and the unlock command are not present at the same time, the system proceeds to the next step of judgment.

[0103] The fourth step is to determine whether the contacts of the motor protector MP1 are normal.

[0104] When the pitch driver detects that the motor protector MP1 contact is normal (i.e., DI3 is high), it proceeds to the next step. When the motor protector MP1 contact is abnormal (i.e., DI3 is low), it reports a motor protector MP1 malfunction.

[0105] The fifth step is to execute the blade lock control command of the current wind turbine master controller.

[0106] When the leaf lock control command is executed, the driver P6 will monitor the current value fed back by the current transformer T1 in real time. When the current value is higher than the set overcurrent value, it will report an overcurrent fault in the current transformer and stop controlling the leaf lock. If the current value is normal, it will proceed to the next step.

[0107] The sixth step is that the pitch control program records the blade lock control status of the previous execution cycle and saves it after power failure, that is, it records whether the previous cycle executed a locking or unlocking command.

[0108] This step is used to avoid blade lock abnormal signals or execution conflicts, due to the unpredictable power outage conditions of the wind turbine.

[0109] Step 7: When the pitch control program is executed in this cycle, it will read the blade lock control status A of the previous cycle and the blade lock control status B of the current cycle.

[0110] If both A and B are locked, or one is locked and the other is unlocked, or if the driver P6 detects that either DI1 or DI2 is high, the pitch program determines that the blade lock is locked or in the process of locking. At this time, the pitch system enters the shutdown state and does not execute the blade pitch action (the key is to read and compare the execution instructions of the previous cycle and the current cycle, and at the same time judge the feedback signals of blade lock DI1 and DI2 for joint judgment).

[0111] If, during the above process, the master controller sends a blade opening command, the pitch system will report a conflict between the blade lock and the opening command, refuse to execute the opening command, and remain in the stopped state.

[0112] This solution incorporates hardware and software interlocking and anti-collision designs on the pitch system side to minimize conflicts between blade lock locking and unlocking commands. Simultaneously, the solution defines the controllable angle range of the blade lock; when the blade lock is locked or in the locking process, it refuses to receive pitch-opening commands, preventing blade lock jamming due to command conflicts. Furthermore, power supply monitoring is implemented for the blade lock to detect damage caused by stalling or abnormal power supply.

[0113] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0114] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0115] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A pitch control system, characterized in that, include: The power grid, blade lock, driver, and interlock module; The first interface of the driver is connected to the power grid, the second interface of the driver is connected to the first end of the interlock module, the second end of the interlock module is connected to the power grid, and the third end of the interlock module is connected to the leaf lock. The driver is used to receive locking or unlocking commands and control the interlock module to transmit currents of different phase sequences to the blade lock. The blade lock is used to lock or unlock the pitch motor according to the received currents of different phase sequences.

2. The pitch control system according to claim 1, characterized in that, The interlock module includes a first power supply, a first input terminal of which is connected to the neutral line interface of the power grid, and a second input terminal of which is connected to at least one phase of the three-phase power supply interface of the power grid.

3. The pitch control system according to claim 2, characterized in that, The interlock module includes a first relay, a second relay, a first contactor, and a second contactor. The driver also includes a third interface. The second interface of the driver includes a first pin and a second pin. The first pin is used to output current when the locking command is received, and the second pin is used to output current when the unlocking command is received. The first pin of the driver is connected to the first end of the coil of the first relay, the second pin of the driver is connected to the first end of the coil of the second relay, and the second end of the coil of the first relay and the second end of the coil of the second relay are connected together to the third interface of the driver. The first input terminal of the first power supply is connected to the neutral line interface of the power grid, the second input terminal of the first power supply is connected to at least one phase of the three-phase power supply interface of the power grid, and the first terminal of the normally open contact switch of the first relay and the first terminal of the normally open contact switch of the second relay are connected together to the positive output terminal of the first power supply. The second terminal of the normally open contact switch of the first relay is connected to the first terminal of the normally closed contact switch of the second contactor, and the second terminal of the normally closed contact switch of the second contactor is connected to the first terminal of the coil of the first contactor. The second terminal of the normally open contact switch of the second relay is connected to the first terminal of the normally closed contact switch of the first contactor, and the second terminal of the normally closed contact switch of the first contactor is connected to the first terminal of the coil of the second contactor. The second end of the coil of the first contactor and the second end of the coil of the second contactor are connected together and then connected to the negative output terminal of the first power supply; The first terminal of the normally open contact switch of the first contactor is connected to the three-phase power interface of the power grid, and the first terminal of the normally open contact switch of the second contactor is connected to the three-phase power interface of the power grid. The second terminal of the normally open contact switch of the first contactor and the second terminal of the normally open contact switch of the second contactor are respectively connected to the input terminal of the leaf lock.

4. The pitch control system according to claim 3, characterized in that, The three-phase power supply interface of the power grid includes a first-phase interface, a second-phase interface, and a third-phase interface; The first interface of the normally open contact switch of the first contactor is connected to the first phase interface, the second interface of the normally open contact switch of the first contactor is connected to the second phase interface, and the third interface of the normally open contact switch of the first contactor is connected to the third phase interface. The first interface of the normally open contact switch of the second contactor is connected to the first phase interface, the second interface of the normally open contact switch of the second contactor is connected to the third phase interface, and the third interface of the normally open contact switch of the second contactor is connected to the second phase interface. The normally open contact switch of the first contactor is used to convert the three-phase AC power output from the power grid into the phase sequence corresponding to the locking command, and the normally open contact switch of the second contactor is used to convert the three-phase AC power output from the power grid into the phase sequence corresponding to the unlocking command.

5. The pitch control system according to claim 3, characterized in that, The interlock module further includes a third relay and a fourth relay; the input terminal of the leaf lock includes a first input interface and a second input interface; the output terminal of the leaf lock includes a first output interface and a second output interface; and the driver further includes a fourth interface. The second terminals of the normally open contact switches of the first contactor and the second contactor are connected together and then connected to the first input interface of the leaf lock. The second input interface of the leaf lock is connected to the positive output terminal of the first power supply. The first output terminal of the leaf lock is connected to the first terminal of the coil of the third relay, the second output terminal of the leaf lock is connected to the first terminal of the coil of the fourth relay, and the second terminals of the coils of the third relay and the fourth relay are connected together and then connected to the negative output terminal of the first power supply. The first terminal of the normally open contact switch of the third relay is connected to the first pin of the fourth interface, and the first terminal of the normally open contact switch of the fourth relay is connected to the second pin of the fourth interface. The second terminals of the normally open outgoing contact switches of the third relay and the fourth relay are connected together and then connected to the third pin of the second interface of the driver. The third pin of the second interface is the power supply pin. The fourth interface of the driver is used to determine the locking state of the pitch motor based on the electrical signal output by the blade lock.

6. The pitch control system according to claim 5, characterized in that, The system also includes a current transformer; The current acquisition unit of the current transformer is connected in series with at least one phase of the connection line between the first input interface of the leaf lock and the first contactor and the second contactor; The first end of the current transformer is connected to the positive output terminal of the first power supply, the second end of the current transformer is grounded, and the third end of the current transformer is connected to the fourth pin of the second interface of the driver. The fourth pin of the second interface of the driver is used to determine the fault condition of the pitch motor based on the received electrical signal.

7. The pitch control system according to claim 6, characterized in that, The system also includes a motor protector; The first contactor and the second contactor are connected to the three-phase power interface of the power grid through the motor protector, which is used to provide overcurrent protection for the first contactor, the second contactor, and the leaf lock.

8. The pitch control system according to claim 7, characterized in that, The system also includes a first surge protector, a second surge protector, a third surge protector, a fourth surge protector, a first air switch, a second air switch, and a load switch; The input terminal of the load switch is connected to the power grid, and the output terminal of the load switch is connected to the input terminal of the first air switch. The output terminal of the first air switch is connected to the input terminal of the motor protector, the input terminal of the first power supply, and the first interface of the driver, respectively. The second input terminal of the first power supply is connected to the output terminal of at least one corresponding first air switch in the three-phase power interface of the power grid through the second air switch. The first surge protector is connected between the power grid and the load switch, and the first surge protector is used for; The third terminal of the current transformer is connected to the fourth pin of the second interface of the driver through the second surge protector; The coils of the first relay and the second relay are connected to the third interface of the driver through the third surge protector; The first power supply is connected to the leaf lock, the normally open contact switch of the first relay, and the normally open contact switch of the second relay through the fourth surge protector; The first surge protector, the second surge protector, the third surge protector, and the fourth surge protector are all used for overcurrent protection. The load switch is used to control the power supply to the pitch control system. The first air switch is used to provide short-circuit protection for the blade lock, and the second air switch is used to provide short-circuit protection for the first power supply.

9. The pitch control system according to claim 1, characterized in that, The driver also includes a fifth interface and a sixth interface, and the first interface of the driver includes an input pin and an output pin; The input pin of the first interface of the driver is connected to the power grid, the output pin of the first interface of the driver is connected to the pitch motor, and the output pin of the first interface of the driver is used to supply power to the pitch motor. The fifth interface of the driver is connected to the pitch motor, and the fifth interface is used to control the speed of the pitch motor; The sixth interface of the driver is connected to the pitch motor. The sixth interface is used to collect the current and blade angle of the pitch motor. The driver is also used to generate the locking command and the unlocking command based on the current and blade angle collected by the sixth interface.

10. A pitch control device, characterized in that, The pitch control device includes the pitch control system according to any one of claims 1-9.

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