An emergency yaw control system for a wind turbine generator set under power failure

Abstract

The present invention relates to the technical field of wind turbine units. Specifically, it relates to an emergency yaw control system in the case of power loss of a wind power generating unit. The original circuit of the fan is respectively connected to one end of switch Q1, one end of switch Q2, one end of switch Q3, and one end of switch Q4. The other ends of switch Q1, switch Q2, switch Q3, and switch Q4 are respectively connected to the tower base, the 1st interface of the step-down to DC transformer, and the input end of relay K1. The 3rd interface of the step-down to DC transformer is connected to the positive pole of diode Z1. The 2nd interface of the step-down to DC transformer, the output end of relay K1, the negative pole of diode Z1, and the 4th interface of the step-down to DC transformer are respectively connected to the original circuit of the fan. The emergency power supply is connected to the tower base through a quick plug, and the tower base is connected to the second wind turbine unit.

Description

Technical Field

[0001] The present invention relates to the technical field of wind turbine units, and more particularly, to an emergency yaw control system for a wind power generating unit in the event of power loss. Background Art

[0002] With the increasing number of wind power generating units, the requirements for safety by each power generation unit are also getting higher and higher, and preventing the occurrence of runaway accidents of wind turbine units has become a key task in recent years. In order to avoid runaway accidents as much as possible, the emergency yaw system of wind turbine units has emerged. At present, the common emergency yaw system is mainly a passive control system based on software and hardware. When it detects situations such as overspeed of the unit or blade pitch jamming, it automatically starts the emergency yaw circuit through software and hardware control to reduce the unit speed. However, when the power supply of the unit is lost due to faults in the power grid, lines, transformer substations, etc., the function of automatically starting the emergency yaw circuit through software and hardware control will fail, resulting in the occurrence of runaway accidents. Based on this, in view of the above problems, we have designed an emergency yaw control system for a wind power generating unit in the event of power loss. Summary of the Invention

[0003] The purpose of the present invention is to provide an emergency yaw control system for a wind power generating unit in the event of power loss, which is used to solve the above technical problems.

[0004] The embodiments of the present invention are implemented through the following technical solutions:

[0005] An emergency yaw control system for a wind power generating unit in the event of power loss, comprising: the original circuit of the fan, switch Q1, switch Q2, switch Q3, switch Q4, step-down AC-DC transformer, diode Z1, relay K1, tower base, emergency power supply, and second wind turbine unit; the original circuit of the fan is respectively connected to one end of switch Q1, one end of switch Q2, one end of switch Q3, and one end of switch Q4, and the other ends of switch Q1, switch Q2, switch Q3, and switch Q4 are respectively connected to the tower base, the 1st interface of the step-down AC-DC transformer, and the input end of relay K1. The 3rd interface of the step-down AC-DC transformer is connected to the positive pole of diode Z1, and the 2nd interface of the step-down AC-DC transformer, the output end of relay K1, the negative pole of diode Z1, and the 4th interface of the step-down AC-DC transformer are respectively connected to the original circuit of the fan. The emergency power supply is connected to the tower base through a quick plug, and the tower base is connected to the second wind turbine unit.

[0006] Optionally, the original circuit of the fan includes: a first power input terminal, a second power input terminal, a third power input terminal, a fourth power input terminal, a fifth power input terminal, switch A1, switch A2, switch A3, switch A4, switch A5, a yaw motor, an electromagnetic brake, diode Z2, a hydraulic brake, a first power negative terminal, a second power negative terminal; the first power input terminal is connected to one end of switch A1, and the other end of switch A1 is respectively connected to the yaw motor and one end of switch Q1; the second power input terminal is connected to one end of switch A2, and the other end of switch A2 is respectively connected to the yaw motor and one end of switch Q2; the third power input terminal is connected to one end of switch A3, and the other end of switch A3 is respectively connected to the yaw motor and one end of switch Q3; the fourth power input terminal is connected to one end of switch A4, and the other end of switch A4 is respectively connected to one end of the electromagnetic brake and one end of switch Q4; the other end of the electromagnetic brake, the 2nd interface of the step-down to DC transformer, and the output terminal of relay K1 are respectively connected to the first power negative terminal; the fifth power input terminal is connected to one end of switch A5, and the other end of switch A5 is connected to the positive electrode of diode Z2; the negative electrode of diode Z2 is respectively connected to the negative electrode of diode Z1 and one end of the hydraulic brake; the other end of the hydraulic brake and the 4th interface of the step-down to DC transformer are respectively connected to the second power negative terminal.

[0007] Optionally, a switch A6 and a switch A7 are further provided at the first power negative terminal; the other end of the electromagnetic brake, the 2nd interface of the step-down to DC transformer, and the output terminal of relay K1 are respectively connected to one end of switch A6; the other end of switch A6 is connected to one end of switch A7; and the other end of switch A7 is connected to the first power negative terminal.

[0008] Optionally, the tower base includes: switch QS1, switch QS2, switch QS3, switch QS4, tower base power supply, switch S1, switch S2, switch S3, switch S4, relay K2, switch F1; the other end of switch Q1 is connected to one end of switch QS1, the other end of switch Q2 is connected to one end of switch QS2, the other end of switch Q3 is connected to one end of switch QS3, the other end of switch Q4, the No. 1 interface of the step-down AC-DC transformer, and the input end of relay K1 are respectively connected to one end of switch QS4, the first input end of the tower base power supply is connected to one end of switch S1, the second input end of the tower base power supply is connected to one end of switch S2, the third input end of the tower base power supply is connected to one end of switch S3, the fourth input end of the tower base power supply is connected to one end of switch S4, the power negative pole of the tower base power supply is connected to the input end of relay K2, the output end of relay K2 is connected to one end of switch F1, and the other end of switch F1 is connected to the second wind turbine generator.

[0009] Optionally, the normally open point 11 of relay K2 is connected to the set power supply terminal, and the normally open point 14 of relay K2 is connected to the DI interface of the tower base for alarming when the emergency yaw cable is disconnected.

[0010] Optionally, the emergency power supply includes switch VS1, switch VS2, switch VS3, switch VS4, and a diesel generator; the diesel generator is respectively connected to one end of switch VS1, one end of switch VS2, one end of switch VS3, and one end of switch VS4, the other end of switch VS1 is respectively connected to the other end of switch S1, the other end of switch QS1, and the second wind turbine generator, the other end of switch VS2 is respectively connected to the other end of switch S2, the other end of switch QS2, and the second wind turbine generator, the other end of switch VS3 is respectively connected to the other end of switch S3, the other end of switch QS3, and the second wind turbine generator, and the other end of switch VS4 is respectively connected to the other end of switch S4, the other end of switch QS4, and the second wind turbine generator.

[0011] The technical solution of the embodiment of the present invention has at least the following advantages and beneficial effects:

[0012] The present invention provides an emergency yaw control system for a wind turbine generator set under power failure. When the wind turbine generator set loses power, gets out of control, the rotational speed continuously rises, and the unit runs away, the emergency yaw control system is started by power supply from a backup power source, and the yaw system is forced to drive the nacelle to yaw by 90°, so that the impeller side faces the wind, thereby achieving the effect of reducing the rotational speed of the unit. The present invention is clear, easy to implement, effective, and has a high input-output ratio, simplifies complex problems, and has no negative impact on the fan; there is no software or program modification, only the circuit topology is modified. The emergency system is independent of the software and the safety chain, and electrical isolation is added between the original circuit. When the unit operates normally, there is no energy consumption loss in this circuit. The input control strategy of the emergency power supply and the motor starting method have general applicability, and the starting sequence meets the five-prevention requirements, and can ensure accurate input in extreme cases.

[0013] The present invention can effectively reduce the occurrence of secondary disasters when the unit runs away, and has strong operability. When the unit runs away, there is always a risk of blade breakage and collapse at any time, and personnel cannot approach. The present invention adopts the method of extending the backup power cable and interconnecting the cables of two units to supply power to ensure the safe operation distance; adopts the dual-backup power source configuration of the tower base power source of the opposite-side unit and the diesel generator to ensure that the emergency system can be reliably started in extreme cases, without potential hazards of expanding equipment failures and personal injuries and other secondary disasters.

[0014] The present invention has the function of monitoring the state of the emergency circuit and has strong reliability. Since the external cable of the unit is not energized when the emergency yaw is not started, if the cable is disconnected due to the influence of construction along the way, it cannot be detected in time, reducing the reliability of the emergency circuit. On the basis of regularly testing the function of the emergency system, the present invention adds an alarm signal for the disconnection of the yaw cable, which can monitor the state of the external cable of the emergency system of the unit in real time to ensure that the emergency system is available at any time. Description of the Drawings

[0015] Figure 1 It is the circuit schematic diagram of the direct control of the main control PLC and the soft start of the yaw provided by the present invention;

[0016] Figure 2 It is the circuit schematic diagram of the yaw frequency converter provided by the present invention. Detailed Embodiments

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, rather than all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Such as Figure 1 、 Figure 2As shown in the figure, the present invention provides one of the embodiments: an emergency yaw control system for a wind turbine generator set. When the wind turbine generator set loses power and gets out of control, and its rotational speed keeps rising, considering that the unit may have risks of overspeed and collapse at any time and personnel cannot approach, the method of extending the backup power cable is adopted to ensure a safe operating distance. At the same time, considering the great difficulty in maintaining the power operation box set outdoors and the configuration of dual backup power supplies, the method of interconnecting the cables of two units is adopted for power supply. The composition of this system includes the following steps:

[0019] Step 1. Interconnection cable setting: Lay 5-core 400VAC cables between two units in an overhead or buried manner. Among them, 1 core of 230VAC is used as the brake control power supply (electromagnetic brake 230VAC and hydraulic brake 230VAV / 24VDC), 3 cores of 400VAC are used as the yaw motor power supply (when the yaw motor power supply is 690VAC, it can be achieved by changing the voltage level of the backup power supply or the motor wiring method), and 1 core of 230VAC is used as the cable disconnection detection line. The cable layout path avoids the box transformer and areas prone to fire.

[0020] Step 2. Emergency yaw system power circuit setting: Considering the failure of electrical components in extreme cases, this circuit tries to reduce the configuration of components such as contactors and relays as much as possible. Connect in parallel at the power supply terminal blocks of the yaw motor and the electromagnetic brake of the yaw motor in the nacelle respectively, and lead out 4-core cables to the tower base. At the same time, install a 230VAC / 24VDC switching power supply in parallel at the external 230VAC electromagnetic brake power supply to supply power to the hydraulic brake solenoid valve (in the original circuit, if there are relay and air switch nodes in the return-to-zero line, the nodes need to be short-circuited). Considering the non-interference of power supplies and safe use, positive and negative isolation needs to be added. Positive isolation (the power of the original circuit is not supplied to the emergency circuit), negative isolation (the power of the emergency circuit is not supplied to the original circuit). For 24VDC, diodes can be added, and for 230VAC and 400VAC, contactors, relays or shunt trip releases, etc. need to be added. For the yaw system directly controlled by the common main control PLC or controlled by a yaw soft starter, if there are normally open contacts of contactors in the yaw motor and electromagnetic brake release circuit, there is no need to add negative isolation (there is no contactor in the yaw frequency converter control, and a circuit breaker Q2 with a shunt trip release needs to be added in series in the 4-wire between the yaw frequency converter and the yaw motor and is controlled by the externally introduced single-phase power supply for opening the brake). The positive and negative isolation of the hydraulic brake release 24VDC is achieved by connecting two opposite diodes in series. Set a positive isolation contactor K1 (the contactor is controlled by single-phase 230VAC) between the 4-core cables from the nacelle to the tower base to ensure normal operation during the main control automatic yaw.

[0021] Isolate switches QS1, QS2, QS3, and QS4 are installed at the tower base (used to isolate this unit during mutual operation). Two sets of wiring are paralleled at the tower base and connected to the 400VAC of the tower base or the diesel generator through two sets of isolate switches S1, S2, S3, S4 and VS1, VS2, VS3, VS4 (a quick plug is set at the reserved interface with the diesel generator). When the unit is operating normally, isolate switches QS1, QS2, QS3, and QS4 are in the closed state, and isolate switches S1, S2, S3, S4 and VS1, VS2, VS3, VS4 are in the open state. Mechanical five-prevention locks are set for the isolate switches according to the operation sequence.

[0022] Step 3: Emergency yaw system startup principle and operation steps: When an emergency situation such as power loss or speed runaway occurs in a certain unit, personnel go to the opposite side unit for operation.

[0023] ① At the tower base, open the isolate switches QS1, QS2, QS3, and QS4 connecting the emergency power supply of the nacelle yaw system of itself (to prevent affecting the yaw of this unit when operating on the opposite side unit).

[0024] ② When there is power at the tower base, give priority to using the tower base power supply. First, close the isolate switch S4. At this time, the K1 contactor is energized and the emergency line from the tower base to the yaw system is connected. The electromagnetic brake relay is energized and the brake is released. The 230VAC / 24VDC switching power supply works, and the solenoid valve is energized and the hydraulic pressure is released (if the unit is equipped with a yaw frequency converter, the shunt trip of the Q2 circuit breaker connected in series between the yaw motor and the yaw frequency converter, as Figure 2 ). After 2S, then close the isolate switches S1, S2, and S3. The yaw motor is energized and the clockwise yaw command is executed. Keep an eye on the fan speed and yaw angle at all times. When the speed drops to the safe speed or reaches 90° for side-facing the wind, execute the stop command. First, open the isolate switches S1, S2, and S3. After 2S, open the S4 isolate switch. At this time, the fan stops yawing. Then close the isolate switches QS1, QS2, QS3, and QS4 to restore the original state.

[0025] ③ When the tower base loses power, quickly connect the diesel generator through the quick plug, start the emergency power supply, and the operation principle of the isolate switches VS1, VS2, VS3, and VS4 is the same as the principle of operating S1, S2, S3, and S4 in ②.

[0026] Step 4, Emergency Yaw Cable Disconnection Alarm: When the emergency yaw is not started, the external cables of the unit are not energized. If the cables are disconnected due to construction along the way, it cannot be detected in time, reducing the reliability of the emergency circuit. To detect cable disconnection faults in time, an alarm signal for yaw cable disconnection is added. One more core is added to the same strand as the power cable, and a 230VAC power supply is connected from the tower base of the opposite unit and led to the A1 terminal of the K2 relay at the tower base of this unit. A2 returns to zero locally. A set of normally open contacts of the K2 relay is used. One end introduces 24VDC, and the other end is connected to the spare DI interface at the tower base and named "Emergency Yaw Cable Disconnection Alarm". The high-level signal is normal, and an alarm is given when the cable is disconnected or the secondary wiring becomes loose and turns into a low level.

[0027] In this embodiment, when a single unit loses power, an adjacent unit or a diesel generator is used as a backup power source to manually start the emergency yaw control circuit and force the unit to yaw, so that the impeller side faces the wind, thereby reducing the unit speed.

[0028] To sum up, in this embodiment, when the wind turbine loses power, gets out of control, the speed continues to rise, and the unit runs away, the emergency yaw control system is started by supplying power from the backup power source, and the yaw system is forced to drive the nacelle to yaw 90°, so that the impeller side faces the wind, thereby reducing the unit speed. The present invention is clear, easy to implement, effective, and has a high input-output ratio. It simplifies complex problems and has no negative impact on the fan; there is no software or program modification, only the circuit topology is modified. The emergency system is independent of software and independent of the safety chain, and electrical isolation is added between the original circuit. When the unit is operating normally, there is no energy consumption loss in this circuit. The input control strategy of the emergency power supply and the motor starting method have universal applicability, and the starting sequence meets the five-prevention requirements, and can ensure accurate input in extreme cases.

[0029] This embodiment can effectively reduce the occurrence of secondary disasters when the unit runs away and has strong operability. When the unit runs away, there is always a risk of blade breakage and collapse at any time, and personnel cannot approach. The present invention adopts the method of extending the backup power cable and interchanging the cables of two units to supply power to ensure the safe operation distance; adopts the dual-backup power supply configuration of the tower base power supply of the opposite unit and the diesel generator to ensure that the emergency system can be reliably started in extreme cases, without potential hazards of expanding equipment failures and personal injuries and other secondary disasters.

[0030] This embodiment has the function of monitoring the status of the emergency circuit and has strong reliability. When the emergency yaw is not started, the external cables of the unit are not energized. If the cables are disconnected due to construction along the way, it cannot be detected in time, reducing the reliability of the emergency circuit. Based on the regular test of the emergency system function, the present invention adds an alarm signal for yaw cable disconnection, which can monitor the status of the external cables of the emergency system unit in real time to ensure that the emergency system is available at any time.

[0031] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An emergency yaw control system for a wind turbine generator under power failure conditions, characterized in that, Including: The original circuit of the fan, switch Q1, switch Q2, switch Q3, switch Q4, step-down AC-DC transformer, diode Z1, relay K1, tower base, emergency power supply, and second wind turbine generator; the original circuit of the fan is respectively connected to one end of switch Q1, one end of switch Q2, one end of switch Q3, and one end of switch Q4. The other ends of switch Q1, switch Q2, switch Q3, and switch Q4 are respectively connected to the tower base, the 1st interface of the step-down AC-DC transformer, and the input end of relay K1. The 3rd interface of the step-down AC-DC transformer is connected to the positive pole of diode Z1. The 2nd interface of the step-down AC-DC transformer, the output end of relay K1, the negative pole of diode Z1, and the 4th interface of the step-down AC-DC transformer are respectively connected to the original circuit of the fan. The emergency power supply is connected to the tower base through a quick plug, and the tower base is connected to the second wind turbine generator; The original circuit of the fan includes: the first power input terminal, the second power input terminal, the third power input terminal, the fourth power input terminal, the fifth power input terminal, switch A1, switch A2, switch A3, switch A4, switch A5, yaw motor, electromagnetic brake, diode Z2, hydraulic brake, the first power negative pole, and the second power negative pole; the first power input terminal is connected to one end of switch A1, and the other end of switch A1 is respectively connected to the yaw motor and one end of switch Q1. The second power input terminal is connected to one end of switch A2, and the other end of switch A2 is respectively connected to the yaw motor and one end of switch Q2. The third power input terminal is connected to one end of switch A3, and the other end of switch A3 is respectively connected to the yaw motor and one end of switch Q3. The fourth power input terminal is connected to one end of switch A4, and the other end of switch A4 is respectively connected to one end of the electromagnetic brake and one end of switch Q4. The other end of the electromagnetic brake, the 2nd interface of the step-down AC-DC transformer, and the output end of relay K1 are respectively connected to the first power negative pole. The fifth power input terminal is connected to one end of switch A5, and the other end of switch A5 is connected to the positive pole of diode Z2. The negative pole of diode Z2 is respectively connected to the negative pole of diode Z1 and one end of the hydraulic brake. The other end of the hydraulic brake and the 4th interface of the step-down AC-DC transformer are respectively connected to the second power negative pole; A switch A6 and a switch A7 are also arranged at the first power negative pole. The other end of the electromagnetic brake, the 2nd interface of the step-down AC-DC transformer, and the output end of relay K1 are respectively connected to one end of switch A6. The other end of switch A6 is connected to one end of switch A7, and the other end of switch A7 is connected to the first power negative pole.

2. The emergency yaw control system in the case of power loss of the wind turbine generator set according to claim 1, characterized in that, The tower base includes: switch QS1, switch QS2, switch QS3, switch QS4, tower base power supply, switch S1, switch S2, switch S3, switch S4, relay K2, switch F1; the other end of switch Q1 is connected to one end of switch QS1, the other end of switch Q2 is connected to one end of switch QS2, the other end of switch Q3 is connected to one end of switch QS3, the other end of switch Q4, the No. 1 interface of the step-down AC-DC transformer, and the input end of relay K1 are respectively connected to one end of switch QS4, the first input end of the tower base power supply is connected to one end of switch S1, the second input end of the tower base power supply is connected to one end of switch S2, the third input end of the tower base power supply is connected to one end of switch S3, the fourth input end of the tower base power supply is connected to one end of switch S4, the negative power supply of the tower base power supply is connected to the input end of relay K2, the output end of relay K2 is connected to one end of switch F1, and the other end of switch F1 is connected to the second wind turbine generator.

3. The emergency yaw control system for a wind turbine generator under power loss according to claim 2, characterized in that The normally open point 11 of relay K2 is connected to the set power supply end, and the normally open point 14 of relay K2 is connected to the DI interface of the tower base for alarming when the emergency yaw cable is disconnected.

4. The emergency yaw control system under power failure condition of the wind turbine generator set according to claim 3, characterized in that, The emergency power supply includes switch VS1, switch VS2, switch VS3, switch VS4, and a diesel generator; the diesel generator is respectively connected to one end of switch VS1, one end of switch VS2, one end of switch VS3, and one end of switch VS4, the other end of switch VS1 is respectively connected to the other end of switch S1, the other end of switch QS1, and the second wind turbine generator, the other end of switch VS2 is respectively connected to the other end of switch S2, the other end of switch QS2, and the second wind turbine generator, the other end of switch VS3 is respectively connected to the other end of switch S3, the other end of switch QS3, and the second wind turbine generator, and the other end of switch VS4 is respectively connected to the other end of switch S4, the other end of switch QS4, and the second wind turbine generator.

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