Wind power generation variable pitch control system based on super capacitor module

Abstract

The invention relates to the technical field of electrical control, in particular to a wind power generation variable pitch control system based on a super capacitor module, which comprises a variable pitch control unit, a variable pitch motor, a back-up power supply unit, an external sensor and a motor unit, the back-up power supply unit is connected with the variable pitch control unit, and the variable pitch control unit is connected with the variable pitch motor. The external sensor is connected with the variable pitch control unit which is connected with the motor unit. The direct-current bus supplies power to the variable-pitch control unit, the variable-pitch control unit receives an instruction sent by the master controller and controls the variable-pitch motor to drive the blades to move, the external sensor feeds back the movement condition of the blades to the variable-pitch control system, and the variable-pitch control unit feeds back blade information to the master controller. According to the invention, the problem that the paddle can be continuously retracted when the DC bus is powered down is solved, and the influence of environmental factors on the backup power supply is effectively avoided.

Description

Technical Field

[0001] The present invention relates to the field of electrical control technology, and in particular to a wind power generation pitch control system based on a supercapacitor module, which is a pitch control system for an offshore high-power wind turbine generator set. Background Art

[0002] In recent years, with the vigorous development of clean energy, the new energy industry has also ushered in a new wave of development, and wind power generation occupies a large proportion in the current new energy field. At present, the development of land wind resources has become more mature and saturated, and more and more attention has been paid to marine wind resources.

[0003] The variable pitch system is very important for wind turbines. In the variable pitch system of ordinary wind power generation, the data collected by the anemometer is mainly transmitted to the main control. The variable pitch control unit controls the movement of the variable pitch motor according to the received main control instructions, and adjusts the blade angle at any time according to the changes in wind speed data to ensure that the blade always remains in a safe angle range.

[0004] The current variable pitch system is powered by a DC bus and a backup power supply. When the DC bus loses power, the backup power supply can be used to power the variable pitch system to ensure that the blades can be retracted under any circumstances to avoid the danger of the wind turbine when the power grid fails. Offshore wind resources are more abundant than on land, with higher and more stable wind speeds and larger single-unit capacity of wind turbines, which puts higher requirements on the variable pitch system. In addition, the offshore environment is more severe, with a wide range of temperature changes and high humidity, which has great disadvantages for the traditional use of batteries as backup power supplies. Summary of the invention

[0005] The present invention provides a wind power generation variable pitch control system based on a supercapacitor module, which is used to solve the problem that the blades can continue to be retracted when the DC bus loses power, and effectively avoids the influence of environmental factors on the backup power supply.

[0006] In order to achieve the purpose of the present invention, the technical solution adopted is: a wind power generation pitch control system based on a supercapacitor module, including a pitch control unit, a pitch motor, a backup power supply unit, an external sensor and a motor unit;

[0007] Pitch control unit: used to receive main control instructions to control the movement of the pitch motor;

[0008] Pitch motor: used to receive instructions from the pitch control unit and drive the blades to move;

[0009] Backup power supply unit: used to provide power to the pitch control unit when the DC bus is powered off;

[0010] External sensor: used to detect the movement position of the blade;

[0011] A motor unit, used as an actuator for the blades;

[0012] The backup power supply unit is connected to the pitch control unit, the pitch control unit is connected to the pitch motor, the external sensor is connected to the pitch control unit, and the pitch control unit is connected to the motor unit; the DC bus provides power for the pitch control unit, the pitch control unit receives instructions from the main control, controls the pitch motor to drive the blades to move, the external sensor feeds back the movement of the blades to the pitch control system, and the pitch control unit feeds back the blade information to the main control.

[0013] As an optimization solution of the present invention, each axis uses 6 supercapacitors to form a supercapacitor module as a backup power supply unit, and the 6 supercapacitors are divided into two groups, each group of 3 supercapacitors is connected in series and the two groups are connected in parallel.

[0014] As an optimization scheme of the present invention, the external sensor includes a 5° / 85° photoelectric proximity switch and a 91° / 95° limit switch, and the pitch control unit implements safety chain control. By collecting the signals fed back by the external sensors, it is determined whether each blade is in a safe state, and whether the blade exceeds the limit position is determined by the trigger state of the 91° / 95° limit switch. Whether the blade position is accurate is determined by the trigger state of the 5° / 85° photoelectric proximity switch, and a feedback signal is given to the pitch control unit. If the position of the blade movement is inconsistent with the 5° / 85° photoelectric proximity switch, it indicates a fault and the safety chain must be disconnected.

[0015] As an optimization scheme of the present invention, the pitch control unit is composed of a pitch control cabinet A, a pitch control cabinet B and a pitch control cabinet C. The pitch control cabinet A, the pitch control cabinet B and the pitch control cabinet C are connected by a network topology structure. The pitch control cabinet A, the pitch control cabinet B and the pitch control cabinet C receive instructions from the main control PLC. Data transmission and feedback are performed between each pitch control cabinet and the pitch motor through an encoder. Each pitch control cabinet also provides power supply and brake control signals for the pitch motor. Each pitch motor is connected to the blade through a reducer, and then connected to the integrated control unit of the pitch control cabinet through an encoder, thereby realizing connection with the main control PLC. The integrated control unit receives control commands from the main control PLC, drives the pitch motor to perform pitch operations on the blades, and controls the pitch motor to perform retracting operations on the blades when a fault is detected.

[0016] As an optimization solution of the present invention, the pitch control unit is driven by a pitch servo driver, each pitch servo driver independently controls a blade, each pitch control unit requires an independent backup power supply, and each supercapacitor module does not affect each other.

[0017] As an optimization solution of the present invention, the variable pitch control unit adjusts the blade angle at any time according to the change of wind speed data to ensure that the blade always remains within a safe angle range.

[0018] The present invention has positive effects: 1) The present invention adopts the design of supercapacitor module as the backup power supply of the variable pitch system of the offshore high-power unit, which is used to solve the problem that the blades can continue to be retracted when the DC bus loses power, and effectively avoids the influence of environmental factors on the backup power supply;

[0019] 2) The present invention uses a supercapacitor module as a backup power supply, which is less affected by changes in environmental factors such as on-site temperature and humidity, has a long service life, and can provide energy for the pitch control system at any time in an emergency, so that the blades can return to a safe position;

[0020] 3) The present invention effectively saves system costs, reduces dependence on foreign supercapacitors and drivers, and has high cost performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0022] Figure 1 It is a schematic diagram of the structure of the backup power supply unit of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the hub layout of the present invention;

[0024] Among them, 1. backup power supply unit, 2. external sensor, 3. reducer. DETAILED DESCRIPTION

[0025] like Figure 1 As shown, the present invention discloses a wind power generation pitch control system based on a supercapacitor module, including a pitch control unit, a pitch motor, a backup power supply unit, an external sensor and a motor unit;

[0026] Pitch control unit: used to receive the main control command to control the movement of the pitch motor. The core of this unit is the pitch servo driver. The pitch servo driver uses Zhongcheng Excellence PD-C620A driver with a rated output current of 55A, which meets the requirements for the use of pitch motors in large offshore aircraft projects.

[0027] Pitch motor: used to receive instructions from the pitch control unit to drive the blades to move; the pitch motor uses the E01220A103 motor, which has a rated torque of 150Nm and an S6 torque of 400Nm. The high torque can meet the requirements of large blade rotation and propeller return in case of failure of large-power offshore wind turbines; the anti-corrosion grade complies with ISO 12944-C4 grade, meeting the high anti-corrosion requirements of the offshore operating environment.

[0028] Backup power supply unit: used to provide power to the pitch control unit when the DC bus is powered off; each axis uses 6 supercapacitors (6 10F TIG-1W160P010R0L supercapacitors) to form a supercapacitor module as a backup power supply unit. The 6 supercapacitors are divided into two groups, each with 3 supercapacitors connected in series and the last two groups in parallel. The backup power supply unit can be fully charged within 20 minutes. When the power grid fails and causes a power outage, it can quickly discharge to provide energy for the pitch control unit to control the blades to retract to a safe position.

[0029] Advantages of using TIG-1W160P010R0L supercapacitor:

[0030] 1. Long service life: At 25°C, the expected working time at rated voltage is up to 10 years, and it can complete 500,000 charge and discharge cycles. The installation of the variable pitch system of offshore wind turbines is very labor-intensive and resource-intensive, and the service life of the backup power supply is an important factor to consider;

[0031] 2. High power density: The charging and discharging process is a pure physical reaction, which is convenient, fast and rapid. The discharge capacity of supercapacitors per unit volume is more than 20 times that of rechargeable batteries. Offshore wind turbines have high power and large blades, resulting in a greater load than onshore wind turbines. The energy requirements for backup power storage are higher, but the hub space is limited, so there are strict requirements for power density. A single TIG-1W160P010R0L supercapacitor stores 35.56Wh of energy (Estored), which meets the load requirements.

[0032] 3. Faster charging and discharging speed: The internal resistance of the supercapacitor is small (only 150mΩ), so the time constant RC of the capacitor is very small and the charging time is very short;

[0033] 4. Good high and low temperature performance: Since the charging and discharging process of supercapacitors is a purely physical process, the change in temperature has little effect on the capacitance;

[0034] 5. Environmental protection: The electrolyte is non-toxic and harmless, the charging and discharging process has no components and is noise-free, with a high safety factor.

[0035] 6. High efficiency: When the variable pitch system retracts the propellers in an emergency, the variable pitch drive requires high torque and high speed, and the backup power supply requires high output current and short action time. The maximum peak current of the TIG-1W160P010R0L supercapacitor is 320A, which meets the requirements of retracting the propellers in an emergency.

[0036] Table 1 Comparison between supercapacitor module and battery

[0037] Basic parameters Supercapacitor Battery <![CDATA[Power density / W·kg -1 > 3710 <500 <![CDATA[Energy density / Wh·kg -1 > 3.09 30-40 Cycle times / times <![CDATA[5X10 5 ]]> <![CDATA[<10 3 ]]> Charging time ＜20m 1-5h Discharge time Less than 5m 0.3-3h Charge and discharge efficiency / % 85-98 70-85

[0038] External sensor 2: used to detect the moving position of the blade; the external sensors include 5° / 85° photoelectric proximity switches and 91° / 95° limit switches. The pitch control unit implements safety chain control by collecting signals fed back by external sensors to determine whether each blade is in a safe state, and determines whether the blade exceeds the limit position by the trigger state of the 91° / 95° limit switch. The blade position is accurate by the trigger state of the 5° / 85° photoelectric proximity switch, and a signal is fed back to the pitch control unit. If the moving position of the blade is inconsistent with the 5° / 85° photoelectric proximity switch, it indicates a fault and the safety chain must be disconnected.

[0039] A motor unit, used as an actuator for the blades;

[0040] The backup power supply unit is connected to the pitch control unit, the pitch control unit is connected to the pitch motor, the external sensor is connected to the pitch control unit, and the pitch control unit is connected to the motor unit; the DC bus provides power for the pitch control unit, the pitch control unit receives instructions from the main control, controls the pitch motor to drive the blades to move, the external sensor feeds back the movement of the blades to the pitch control system, and the pitch control unit feeds back the blade information to the main control.

[0041] The pitch control unit and backup power supply unit are respectively located in the capacitor cabinet and pitch control cabinet of the pitch cabinet. The pitch control cabinet is made of highly anti-corrosion materials and meets the IP54 protection grade as a whole. At the same time, the anti-corrosion grade complies with ISO 12944-C4 grade, meeting the high anti-corrosion requirements of the offshore operation environment. All external wiring harnesses and wiring harness overloads meet the high anti-corrosion requirements of offshore operation.

[0042] The pitch control unit is driven by a pitch servo driver. Each pitch servo driver independently controls a blade. Each pitch control unit requires an independent backup power supply. Each supercapacitor module does not affect each other. The pitch control unit adjusts the blade angle at any time according to the wind speed data to ensure that the blade always remains within the safe angle range.

[0043] The characteristics of wind power generation pitch control system based on supercapacitor module are:

[0044] Each axis uses six 10F TIG-1W160P010R0L supercapacitors in a "three-in-two-parallel" configuration (that is, six capacitors are divided into two groups, each group of three capacitors is connected in series and the last two groups are connected in parallel) to form a supercapacitor module as a backup power supply for the pitch control system. It can be fully charged within 20 minutes, and when a power grid failure causes power outage, it can quickly discharge to provide energy for the pitch control system to control the blades to retract to a safe position.

[0045] The use of supercapacitor modules as backup power sources is less affected by changes in on-site temperature, humidity and other environmental factors, has a longer service life, and can provide energy to the pitch control system at any time in an emergency, allowing the blades to return to a safe position.

[0046] The variable pitch control system uses three PD-C620A drivers. Each driver independently controls a blade. Each control system requires an independent backup power supply, and each supercapacitor module does not affect each other.

[0047] Combined with the specific examples on site, the implementation plan is as follows:

[0048] First, the pitch control unit consists of three independent pitch control cabinets. The slip ring first provides 400V power to pitch control cabinet B, and then the pitch control cabinet B leads out 400V power to pitch control cabinet A and pitch control cabinet A; the pitch control cabinets are connected by a network topology structure, and the three pitch control cabinets use the standard CANOPEN communication protocol. The main control PLC is the master site, and pitch control cabinet A, pitch control cabinet B and pitch control cabinet C are slave sites respectively. They receive control instructions from the master control and feed back the information of each blade to the master control, thereby realizing data transmission between the master control and the pitch control unit. At the same time, the pitch control unit can also implement safety chain control. By collecting signals fed back by external sensors, it can determine whether each blade is in a safe state. (The triggering state of the 91° and 95° limit switches is used to determine whether the blade exceeds the limit position, and the triggering state of the 5° and 82° contact switches is used to determine whether the blade position is accurate. When the blade moves to 5°, the 5° proximity switch must be triggered to give feedback to the pitch control system. If it is triggered at other positions, it means that the system has a fault and the safety chain must be disconnected.

[0049] like Figure 2 As shown, the pitch control cabinet is implemented. When the entire pitch control system receives instructions from the main control PLC without any faults, the pitch control unit drives the pitch motor to adjust the blade position. Data transmission and feedback are carried out between each pitch control cabinet and the pitch motor through an encoder. At the same time, each pitch control cabinet also provides power and brake control signals for the pitch motor. Each pitch motor is connected to the blade through a reducer 3, and then connected to the integrated control unit of the pitch control cabinet through an encoder, thereby realizing the connection with the main control PLC; the integrated control unit receives the control command of the main control PLC, drives the pitch motor to perform pitch operation on the blade, and controls the pitch motor to perform retracting operation on the blade when a fault is detected.

[0050] When the DC bus loses power or other emergency situations make it impossible to power the entire pitch control system, the backup power supply composed of supercapacitor modules can continue to provide energy to the pitch control system so that the pitch control system can complete the above operations.

[0051] The working principle of the present invention is: the servo control unit receives the main control instruction to control the motor unit to adjust the movement of the blades, the backup power supply unit provides energy for safe propeller retraction operation when the power grid fails, the external sensor unit serves as a limiting signal for the blade position and calibrates the position from 5° to 85°, and the motor unit completes the blade actuator.

[0052] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0053] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A wind power generation pitch control system based on supercapacitor module, Features: It includes a pitch control unit, a pitch motor, a backup power supply unit, an external sensor and a motor unit; Pitch control unit: used to receive main control instructions to control the movement of the pitch motor; Pitch motor: used to receive instructions from the pitch control unit and drive the blades to move; Backup power supply unit: used to provide power to the pitch control unit when the DC bus is powered off; External sensor: used to detect the movement position of the blade; A motor unit, used as an actuator for the blades; The backup power supply unit is connected to the pitch control unit, the pitch control unit is connected to the pitch motor, the external sensor is connected to the pitch control unit, and the pitch control unit is connected to the motor unit; the DC bus provides power for the pitch control unit, the pitch control unit receives instructions from the main control, controls the pitch motor to drive the blades to move, the external sensor feeds back the movement of the blades to the pitch control system, and the pitch control unit feeds back the blade information to the main control.

2. According to claim 1, a wind power generation pitch control system based on a supercapacitor module, Features: Each axis uses 6 supercapacitors to form a supercapacitor module as a backup power supply unit. The 6 supercapacitors are divided into two groups, each group of 3 supercapacitors is connected in series and the last two groups are connected in parallel.

3. According to claim 2, a wind power generation pitch control system based on a supercapacitor module, Features: External sensors include 5° / 85° photoelectric proximity switches and 91° / 95° limit switches. The pitch control unit implements safety chain control by collecting signals fed back by external sensors to determine whether each blade is in a safe state. The trigger state of the 91° / 95° limit switch is used to determine whether the blade exceeds the limit position. The trigger state of the 5° / 85° photoelectric proximity switch is used to determine whether the blade position is accurate, and a signal is fed back to the pitch control unit. If the position of the blade movement is inconsistent with the 5° / 85° photoelectric proximity switch, it indicates a fault and the safety chain must be disconnected.

4. According to claim 3, a wind power generation pitch control system based on a supercapacitor module, Features: The pitch control unit consists of pitch control cabinet A, pitch control cabinet B and pitch control cabinet C. The pitch control cabinet A, pitch control cabinet B and pitch control cabinet C are connected by a network topology. The pitch control cabinet A, pitch control cabinet B and pitch control cabinet C receive instructions from the main control PLC. Data transmission and feedback are carried out between each pitch control cabinet and the pitch motor through an encoder. Each pitch control cabinet also provides power supply and brake control signals for the pitch motor. Each pitch motor is connected to the blade through a reducer, and then connected to the integrated control unit of the pitch control cabinet through an encoder, thereby realizing the connection with the main control PLC. The integrated control unit receives the control command of the main control PLC, drives the pitch motor to perform pitch operation on the blade, and controls the pitch motor to perform retracting operation on the blade when a fault is detected.

5. A wind power generation pitch control system based on a supercapacitor module according to claim 4, Features: The pitch control unit is driven by a pitch servo driver. Each pitch servo driver independently controls a blade. Each pitch control unit requires an independent backup power supply. Each supercapacitor module does not affect each other.

6. A wind power generation pitch control system based on a supercapacitor module according to claim 5, Features: The variable pitch control unit adjusts the blade angle at any time according to changes in wind speed data to ensure that the blade always remains within a safe angle range.

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