Emergency yaw protection method and system for wind turbine generator under extreme condition

Abstract

The embodiment of the invention provides an emergency yaw protection method and system for a wind turbine generator under an extreme condition. The system comprises a signal loop and a control loop which are electrically connected with each other. The signal loop is used for receiving a PLC abnormal signal and a unit overspeed signal and sending a yaw signal to the control loop; and the control loop is used for controlling the wind turbine generator to perform emergency yaw when receiving the yaw signal of the signal loop. According to the emergency yaw protection system for the wind turbine generator set under the extreme condition, emergency yaw protection can be provided for the wind turbine generator set under the abnormal conditions that a PLC of the wind turbine generator set crashes, restarts and the like, a variable pitch system of the wind turbine generator set fails and cannot execute a pitch returning action, and the rotating speed exceeds the limit, so that the safety of the wind turbine generator set under the extreme condition is ensured, and the service life of the wind turbine generator set is prolonged. The added electrical equipment is low in cost, and the loop transformation is simple and easy to realize.

Description

Technical Field

[0001] The embodiments disclosed herein belong to the field of emergency yaw protection technology for wind turbines, specifically relating to an emergency yaw protection method and system for wind turbines under extreme conditions. Background Technology

[0002] As a crucial component of wind turbine control systems, the reliability and stability of power supply (PLC) systems are constantly improving. However, in practical applications, various abnormal situations can occur, such as PLC crashes and restarts, caused by PLC programming issues leading to task timeouts, excessive CPU usage, and other PLC hardware and software problems. Therefore, wind turbine design standards require that the wind turbine control system incorporate hardware and software protection measures independent of the computer system. This involves using reverse logic design to connect potentially damaging fault nodes in series into a single loop – the wind turbine's safety chain system. The safety chain protection system is the highest level of protection to ensure wind turbine safety.

[0003] The safety chain of a wind turbine is ultimately connected to the pitch system. In other words, the purpose of disconnecting the safety chain is to allow the pitch system to receive a signal and automatically return to its original position. However, the pitch system can also experience abnormal situations. For example, if the pitch system itself experiences overload conditions such as overcurrent, overvoltage, or overtemperature, it will stop working and wait for the overload to reset. In this case, even if the safety chain is disconnected, the blades will not return to their original position, and the generator speed will not decrease, which may lead to the risk of overspeeding.

[0004] When the unit is in danger of overspeed, if the pitch system is abnormal, the normal method is to force the unit to yaw and adjust the nacelle to a crosswind position to reduce the speed. However, due to the abnormality of the PLC, the PLC cannot control the nacelle to yaw, so the yaw wind measurement and speed reduction cannot be achieved. Summary of the Invention

[0005] The embodiments disclosed herein aim to at least solve one of the technical problems existing in the prior art, and provide an emergency yaw protection method and system for wind turbines under extreme conditions.

[0006] In a first aspect, embodiments of this disclosure provide an emergency yaw protection system for wind turbines under extreme conditions, the system comprising a signal circuit and a control circuit electrically connected to each other;

[0007] The signal circuit is used to receive PLC abnormal signals and unit overspeed signals, and to send yaw signals to the control circuit.

[0008] The control loop is used to control the wind turbine to perform emergency yaw when it receives the yaw signal from the signal loop.

[0009] Furthermore, the signal circuit includes a yaw signal relay; the control circuit includes a normally open contact of the yaw signal relay and a yaw control relay connected in series.

[0010] The normally open contact of the yaw signal relay is used to close when the yaw signal relay is activated.

[0011] The yaw control relay is used for electrical connection with the yaw motor of the wind turbine.

[0012] Furthermore, the main contacts of the yaw control relay are located in the power supply circuit of the yaw motor.

[0013] Furthermore, the signal circuit also includes a PLC fault relay and a normally open contact of the PLC fault relay;

[0014] The PLC fault relay is used to electrically connect to the wind turbine PLC and to activate when the PLC malfunctions.

[0015] The normally open contact of the PLC fault relay and the yaw signal relay are connected in series; the normally open contact of the PLC fault relay is used to close when the PLC fault relay is activated.

[0016] Optionally, the PLC fault relay is a pulse relay.

[0017] Furthermore, the signal circuit also includes an overspeed signal relay and an overspeed signal relay normally open contact;

[0018] The overspeed signal relay is used to be electrically connected to the wind turbine and to activate when the wind turbine exceeds the speed limit.

[0019] The normally open contact of the overspeed signal relay is connected in series with the normally open contact of the PLC abnormal relay and the yaw signal relay, and is used to close when the overspeed signal relay is activated.

[0020] Furthermore, the signal circuit also includes a cable twisting protection relay and a normally closed contact of the cable twisting protection relay;

[0021] The cable twisting protection relay is electrically connected to the yaw cam counter of the wind turbine and is used to activate when the nacelle is in the cable twisting position.

[0022] The normally closed contact of the cable twisting protection relay is connected in series with the normally open contact of the PLC abnormal relay, the normally open contact of the overspeed signal relay, and the yaw signal relay, and is used to disconnect when the cable twisting protection relay is activated.

[0023] Optionally, the yaw signal relay is a time relay.

[0024] Optionally, the signal circuit is powered by a 24V DC UPS from the wind turbine.

[0025] Optionally, the control loop is powered by a 230V AC power supply.

[0026] Secondly, embodiments of this disclosure provide an emergency yaw protection method for wind turbines under extreme conditions, employing the system described above, the method comprising:

[0027] The signal circuit receives PLC abnormal signals and unit overspeed signals, and sends yaw signals to the control circuit;

[0028] When the control loop receives the yaw signal from the signal loop, it controls the wind turbine to perform an emergency yaw.

[0029] This disclosure discloses an emergency yaw protection method and system for wind turbines under extreme conditions. It can provide emergency yaw protection for wind turbines when the PLC of the wind turbine malfunctions, restarts, or when the pitch system of the turbine fails and cannot perform the return pitch action and the speed exceeds the limit. This ensures the safety of the turbine under extreme conditions. The added electrical equipment is inexpensive and the circuit modification is simple and easy to implement. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of an emergency yaw protection system for a wind turbine under extreme conditions according to an embodiment of the present disclosure;

[0031] Figure 2 This is a schematic diagram of the power supply circuit for the yaw motor according to another embodiment of the present disclosure;

[0032] Figure 3 This is a schematic diagram of the control logic flow of another embodiment of the present disclosure. Detailed Implementation

[0033] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. Based on the embodiments of this disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this disclosure.

[0034] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0035] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0036] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various components, these components should not be limited by these terms. These terms are used to distinguish one component from another. Therefore, the first component discussed below may be referred to as the second component without departing from the teachings of this disclosure. As used in this disclosure, the term "and / or" includes all combinations of any and more of the associated listed items.

[0037] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of exemplary embodiments, and the modules or processes in the drawings are not necessarily necessary for implementing this disclosure, and therefore cannot be used to limit the scope of protection of this disclosure.

[0038] like Figure 1 As shown, embodiments of this disclosure provide an emergency yaw protection system for wind turbines under extreme conditions, including a signal circuit 100 and a control circuit 200 electrically connected to each other. The signal circuit 100 is used to receive PLC abnormal signals and turbine overspeed signals, and to send a yaw signal to the control circuit 200. The control circuit 200 is used to control the wind turbine to perform emergency yaw when it receives the yaw signal from the signal circuit 100.

[0039] Specifically, a PLC abnormality signal indicates that the wind turbine's PLC has malfunctioned, making it unable to control yaw properly, while an overspeed signal indicates that the wind turbine has exceeded its speed limit. When signal loop 100 receives both signals simultaneously, it sends a yaw signal to control loop 200. Control loop 200 is electrically connected to the wind turbine's yaw motor. Upon receiving the yaw signal, it controls the yaw motor to start, enabling the wind turbine to perform emergency yaw in the event of PLC failure. Signal loop 100 can be powered by the wind turbine's UPS with 24V DC to improve stability. Control loop 200 can be powered by the wind turbine's 230V AC power supply.

[0040] For example, such as Figure 1 As shown, the signal circuit 100 includes a yaw signal relay KT; the control circuit 200 includes a normally open contact KT-1 of the yaw signal relay and a yaw control relay KM connected in series. The normally open contact KT-1 of the yaw signal relay is closed when the yaw signal relay KT is activated. The yaw control relay KM is used for electrical connection with the yaw motor of the wind turbine.

[0041] Specifically, the yaw signal relay KT can be a time relay. When it is energized, it is considered to be sending a yaw signal. The normally open contact KT-1 of the yaw signal relay receives the yaw signal and closes, thereby energizing the yaw control relay KM. For example... Figure 2 As shown, the main contact KM-1 of the yaw control relay KM is located in the power supply circuit of the yaw motor M. A three-phase 400V power supply passes sequentially through the yaw inverter or soft starter and the main contact KM-1 of the yaw control relay to the yaw motor M. When the yaw control relay KM is energized, its main contact KM-1 closes, starting the yaw motor M for emergency yaw. After a preset yaw time, the yaw signal relay KT automatically de-energizes, causing its normally open contact KT-1 to open. This de-energizes the yaw control relay KM, opening its main contact KM-1 and de-energizing the yaw motor M. This allows the wind turbine to automatically stop yawing after the yaw time has elapsed or after the overspeed signal is reset. The subsequent emergency yaw protection control system will again assess PLC malfunctions and wind turbine overspeed, automatically controlling the wind turbine to perform emergency yaw again as needed.

[0042] For example, such as Figure 1 As shown, the signal circuit 100 also includes a PLC fault relay K1 and a normally open contact K1-1 of the PLC fault relay. The PLC fault relay K1 is used for electrical connection with the wind turbine PLC and is activated when the PLC malfunctions. The normally open contact K1-1 of the PLC fault relay and the yaw signal relay KT are connected in series. The normally open contact K1-1 of the PLC fault relay is used to close when the PLC fault relay K1 is activated.

[0043] Specifically, the PLC abnormality relay K1 can be a pulse relay. When the PLC is running normally, it sends pulse signals to the PLC abnormality relay K1 at a fixed frequency. When the PLC experiences an abnormality such as a crash or restart, the pulse signal is lost. At this time, the PLC abnormality relay K1 activates, generating a PLC abnormality signal, which closes its normally open contact K1-1. This allows the PLC abnormality relay K1 to determine whether the PLC is malfunctioning. If an overspeed signal from the unit is also received simultaneously, the yaw signal relay KT will be energized, sending a yaw signal to the control circuit 200.

[0044] For example, such as Figure 1 As shown, the signal circuit 100 also includes an overspeed signal relay (not shown) and an overspeed signal relay normally open contact K2-1. The overspeed signal relay is used for electrical connection with the wind turbine and to activate when the wind turbine exceeds its speed. The overspeed signal relay normally open contact K2-1 is connected in series with the PLC abnormal relay normally open contact K1-1 and the yaw signal relay KT, and is used to close when the overspeed signal relay is activated.

[0045] Specifically, when the wind turbine overspeeds, the overspeed signal relay activates, generating an overspeed signal that closes its normally open contact K2-1. If the PLC is in an abnormal state at this time, the normally open contact K1-1 of the PLC abnormal relay also closes, energizing the yaw signal relay KT. Thus, signal circuit 100 simultaneously receives both the PLC abnormal signal and the turbine overspeed signal, sending a yaw signal to control circuit 200. Conversely, if the wind turbine is no longer overspeeding, the normally open contact K2-1 of the overspeed signal relay opens. Even if signal circuit 100 receives the PLC abnormal signal, the normally open contact K1-1 of the PLC abnormal relay remains closed, and the yaw signal relay KT will not be energized, preventing the system from triggering emergency yaw.

[0046] For example, such as Figure 1 As shown, the signal circuit 100 also includes a cable twisting protection relay (not shown in the figure) and a normally closed contact K3-1 of the cable twisting protection relay. The cable twisting protection relay is electrically connected to the yaw cam counter of the wind turbine and is used to activate when the nacelle is in the cable twisting position. The normally closed contact K3-1 of the cable twisting protection relay is connected in series with the normally open contact K1-1 of the PLC abnormal relay, the normally open contact K2-1 of the overspeed signal relay, and the yaw signal relay KT, and is used to disconnect when the cable twisting protection relay is activated.

[0047] Specifically, the cable twisting protection relay and the wind turbine yaw cam counter will activate the cable twisting protection relay if the current nacelle position is in the cable twisting position. This will cause the normally closed contact K3-1 of the cable twisting protection relay to open, preventing the yaw signal relay KT from being energized. As a result, the signal circuit 100 will be unable to send a yaw signal to the control circuit 200, and the system will immediately stop or fail to trigger emergency yaw. This adds cable twisting protection to the emergency yaw protection system for wind turbines under extreme conditions in this embodiment of the present disclosure.

[0048] The control logic flowchart of the emergency yaw protection system for the above-mentioned wind turbine under extreme conditions can be shown as follows: Figure 3 As shown.

[0049] An emergency yaw protection system for wind turbines under extreme conditions, as disclosed in this embodiment, can provide emergency yaw protection for wind turbines when the PLC of the wind turbine malfunctions, restarts, or when the pitch system of the turbine fails and cannot perform the return pitch action and the speed exceeds the limit. This ensures the safety of the turbine under extreme conditions. The added electrical equipment is inexpensive and the circuit modification is simple and easy to implement.

[0050] This disclosure also provides an emergency yaw protection method for wind turbines under extreme conditions, employing the system described above, the method comprising:

[0051] The signal circuit receives PLC abnormal signals and unit overspeed signals, and sends yaw signals to the control circuit;

[0052] When the control loop receives the yaw signal from the signal loop, it controls the wind turbine to perform an emergency yaw.

[0053] An emergency yaw protection method for wind turbines under extreme conditions, as disclosed in this embodiment, can provide emergency yaw protection for wind turbines when the PLC of the wind turbine malfunctions, restarts, or when the pitch system of the turbine fails and cannot perform the return pitch action and the speed exceeds the limit, thus ensuring the safety of the turbine under extreme conditions. The added electrical equipment is inexpensive and the circuit modification is simple and easy to implement.

[0054] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. An emergency yaw protection system for wind turbines under extreme conditions, characterized in that, The system includes signal circuits and control circuits that are electrically connected to each other; The signal circuit is used to receive PLC abnormal signals and unit overspeed signals, and to send yaw signals to the control circuit. The control loop is used to control the wind turbine to perform emergency yaw when it receives the yaw signal from the signal loop.

2. The system according to claim 1, characterized in that, The signal circuit includes a yaw signal relay; the control circuit includes a normally open contact of the yaw signal relay and a yaw control relay connected in series. The normally open contact of the yaw signal relay is used to close when the yaw signal relay is activated. The yaw control relay is used for electrical connection with the yaw motor of the wind turbine.

3. The system according to claim 2, characterized in that, The main contacts of the yaw control relay are located in the power supply circuit of the yaw motor.

4. The system according to claim 2, characterized in that, The signal circuit also includes a PLC fault relay and a normally open contact of the PLC fault relay; The PLC fault relay is used to electrically connect to the wind turbine PLC and to activate when the PLC malfunctions. The normally open contact of the PLC fault relay and the yaw signal relay are connected in series; the normally open contact of the PLC fault relay is used to close when the PLC fault relay is activated.

5. The system according to claim 4, characterized in that, The PLC fault relay is a pulse relay.

6. The system according to claim 5, characterized in that, The signal circuit also includes an overspeed signal relay and an overspeed signal relay normally open contact; The overspeed signal relay is used to be electrically connected to the wind turbine and to activate when the wind turbine exceeds the speed limit. The normally open contact of the overspeed signal relay is connected in series with the normally open contact of the PLC abnormal relay and the yaw signal relay, and is used to close when the overspeed signal relay is activated.

7. The system according to claim 6, characterized in that, The signal circuit also includes a cable twisting protection relay and a normally closed contact of the cable twisting protection relay. The cable twisting protection relay is electrically connected to the yaw cam counter of the wind turbine and is used to activate when the nacelle is in the cable twisting position. The normally closed contact of the cable twisting protection relay is connected in series with the normally open contact of the PLC abnormal relay, the normally open contact of the overspeed signal relay, and the yaw signal relay, and is used to disconnect when the cable twisting protection relay is activated.

8. The system according to claim 2, characterized in that, The yaw signal relay is a time relay.

9. The system according to any one of claims 1 to 8, characterized in that, The signal circuit is powered by a 24V DC power supply from the wind turbine UPS; the control circuit is powered by a 230V AC power supply.

10. A method for emergency yaw protection of wind turbine units under extreme conditions, characterized in that, The method using the system according to any one of claims 1 to 9 comprises: The signal circuit receives PLC abnormal signals and unit overspeed signals, and sends yaw signals to the control circuit; When the control loop receives the yaw signal from the signal loop, it controls the wind turbine to perform an emergency yaw.

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