Variable pitch drive system, variable pitch drive and master-slave motor driving method

Abstract

The present invention discloses a variable pitch drive system, a variable pitch drive and a master-slave motor drive method, wherein the master-slave motor drive method comprises: a master speed control unit and a slave speed control unit respectively output a master given current instruction and a slave given current instruction to a frequency compensation unit; the frequency compensation unit generates a frequency compensation instruction according to the received master given current instruction and the slave given current instruction, and outputs the frequency compensation instruction to the slave speed control unit; the slave speed control unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, and outputs the slave given current instruction according to the compensated slave frequency deviation instruction. The technical solution of the present invention can improve the transient response and steady-state response of the dual-motor variable pitch drive.

Description

Technical Field

[0001] The present invention relates to the field of pitch control technology, and in particular to a pitch drive system, a pitch drive and a master-slave motor driving method. Background Art

[0002] At present, wind turbines usually use dual motors to output torque to the gear system to drive the blades to execute pitch commands. However, the current dual-motor drive control scheme does not take into account the characteristics of the gear system. When encountering sudden working conditions, it will cause severe impact on the pitch drive system, thereby affecting the overall service life of the wind turbine. Summary of the invention

[0003] The main purpose of the present invention is to provide a master-slave motor driving method, aiming to solve the problem of poor transient response and steady-state response of a dual-motor variable pitch drive.

[0004] To achieve the above-mentioned object, the master-slave motor driving method proposed in the present invention is applied to a pitch drive, wherein the pitch drive comprises a master motor controller, a slave motor controller and a frequency compensation unit, wherein the master motor controller comprises a master speed control unit for outputting a master given current instruction, the slave motor controller comprises a slave speed control unit for outputting a slave given current instruction, the frequency compensation unit is connected to the master speed control unit and the slave speed control unit respectively, and the master-slave motor driving method comprises:

[0005] The main speed control unit and the slave speed control unit respectively output a main given current command and a slave given current command to the frequency compensation unit;

[0006] The frequency compensation unit generates a frequency compensation instruction according to the received master given current instruction and slave given current instruction, and outputs the frequency compensation instruction to the slave speed control unit;

[0007] The slave speed control unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, and outputs a slave given current instruction according to the compensated slave frequency deviation instruction.

[0008] Optionally, the frequency compensation unit generates a frequency compensation instruction according to the received main given current instruction and the slave given current instruction, specifically:

[0009] The frequency compensation unit performs a subtraction operation on the main given current instruction and the slave given current instruction, and generates a frequency compensation instruction according to the subtraction result.

[0010] Optionally, the slave position speed unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, specifically:

[0011] The slave position control unit performs addition calculation on the received frequency compensation instruction and the generated slave frequency deviation instruction, and uses the addition result as the compensated slave frequency deviation instruction.

[0012] Optionally, the master-slave motor driving method further includes:

[0013] The frequency compensation unit also outputs a frequency compensation instruction to the main speed control unit;

[0014] The main speed control unit performs frequency compensation on the generated main frequency deviation command according to the received frequency compensation command, and outputs the main given current command to the main current control unit according to the compensated main frequency deviation command;

[0015] The main current control unit controls the operation of the main motor according to the received main given current command and main feedback current command.

[0016] Optionally, the main speed control unit performs frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, specifically:

[0017] The main speed control unit performs subtraction calculation on the received frequency compensation instruction and the generated main frequency deviation instruction, and uses the subtraction result as the compensated main frequency deviation instruction.

[0018] Optionally, the master-slave motor driving method further includes:

[0019] The main position control unit generates a main given frequency command according to the given position command and the feedback position command and outputs it to the main speed control unit.

[0020] Optionally, the master-slave motor driving method further includes:

[0021] The master position control unit also outputs the generated master given frequency command as a slave given frequency command to the slave speed control unit.

[0022] The present invention further proposes a variable pitch drive for implementing the master-slave motor driving method as described above, the variable pitch drive comprising:

[0023] The main motor controller comprises: a main speed control unit, the main speed control unit is used to output a main given current instruction;

[0024] The slave motor controller includes: a slave speed control unit, the slave speed control unit is used to output a slave given current instruction; and

[0025] A frequency compensation unit, the frequency compensation unit is connected to the master speed control unit and the slave speed control unit respectively to access the master given current command and the slave given current command; the frequency compensation unit is used to generate a frequency compensation command according to the received master given current command and the slave given current command, and output the frequency compensation command to the slave speed control unit, so that the slave speed control unit performs frequency compensation on the generated slave frequency deviation command according to the received frequency compensation command;

[0026] The slave speed control unit is further configured to output a slave given current command to the slave current control unit according to the compensated slave frequency deviation command.

[0027] Optionally, the frequency compensation unit includes:

[0028] A subtraction module, used for respectively accessing the main given current instruction and the slave given current instruction, and for performing a subtraction calculation on the main given current instruction and the slave given current instruction, and outputting a calculation result;

[0029] The frequency compensation generating module is used to access the calculation result of the subtraction module, and generate a corresponding frequency compensation instruction according to the calculation result of the subtraction module and then output it to the slave speed control unit.

[0030] Optionally, the frequency compensation unit is further used to output a frequency compensation instruction to the main speed control unit;

[0031] The main speed control unit is also used to perform frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, and output a main given current instruction according to the compensated main frequency deviation instruction.

[0032] Optionally, the main motor controller further includes:

[0033] The main current control unit is used to control the operation of the main motor according to the main given current command output by the main speed control unit and the main feedback current command received.

[0034] Optionally, the slave motor controller further includes:

[0035] The slave current control unit is used to control the operation of the slave motor according to the slave given current command output by the slave speed control unit and the slave feedback current command received.

[0036] Optionally, the main motor controller further includes:

[0037] The main speed control unit is used to generate a main given frequency command according to the received given position command and feedback position command and output the command to the main speed control unit.

[0038] Optionally, the master speed control unit is further configured to output the generated master given frequency instruction as a slave given frequency instruction to the slave speed control unit.

[0039] The present invention further provides a variable pitch drive system, wherein the variable pitch drive comprises:

[0040] Main motor;

[0041] from the motor; and,

[0042] As in the above-mentioned variable pitch drive, the variable pitch drive is connected to the main motor and the slave motor respectively, and the variable pitch drive is used to control the operation of the main motor and the slave motor respectively.

[0043] The technical solution of the present invention enables the main speed control unit and the slave speed control unit to output the main given current instruction and the slave given current instruction to the frequency compensation unit respectively; the frequency compensation unit generates a frequency compensation instruction according to the received main given current instruction and the slave given current instruction, and outputs the frequency compensation instruction to the slave speed control unit; and the slave speed control unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, and outputs the slave given current instruction according to the compensated slave frequency deviation instruction. The master-slave motor driving method of the present invention can make the torque and speed of the slave motor always consistent with the main motor, so that when encountering sudden working conditions, the dual-motor variable pitch drive system can run smoothly without impact in transient response and steady-state response, thereby avoiding the impact and shock caused by sudden working conditions, thereby solving the problem of poor transient response and steady-state response of the dual-motor variable pitch drive, and can also effectively improve the service life and reliability of the wind turbine. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0045] Figure 1 A schematic diagram of a flow chart of an embodiment of a master-slave motor driving method of the present invention;

[0046] Figure 2 It is a structural schematic diagram of an embodiment of a pitch drive of the present invention;

[0047] Figure 3 It is a structural schematic diagram of another embodiment of the pitch drive of the present invention;

[0048] Figure 4It is a schematic structural diagram of an embodiment of a variable pitch drive system of the present invention.

[0049] Description of Figure Numbers:

[0050] Label name Label name 10 Main motor controller 22 From the current control unit 11 Main speed control unit 30 Frequency compensation unit 12 Main current control unit 31 Subtraction module 13 Main position control unit 32 Frequency compensation generation module 20 From the motor controller 40 Main motor 21 From the speed control unit 50 From the motor

[0051] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] The invention provides a master-slave motor driving method.

[0055] Due to the large clearance between the gears in the gear system, when encountering sudden operating conditions such as starting, reversing, sudden acceleration and deceleration, and sudden load changes, the working conditions corresponding to the two gears are not the same. For example, one gear may be unloaded and the other gear may be overloaded. At this time, the speed characteristics of the dual motors under the same torque are inconsistent, which will cause severe impact and vibration to the variable pitch drive system. During the actual operation of the wind turbine, especially when operating at sea, the load is wind resistance, so the working conditions encountered are relatively complex and sudden. However, due to the poor transient response and steady-state response of the existing dual-motor variable pitch drive, it is unable to cope with the impact and vibration caused by complex and sudden working conditions, which will also affect the safety and service life of the wind turbine.

[0056] For the above problems, refer to Figures 1 to 4 In one embodiment, the master-slave motor driving method includes:

[0057] Step S100, the main speed control unit and the slave speed control unit respectively output a main given current command and a slave given current command to the frequency compensation unit;

[0058] The executor of the master-slave motor driving method of the present invention may be a pitch drive, which is used to control the operation of two motors in a pitch drive system. Two motor controllers may be integrated in the pitch drive corresponding to the two motors, respectively, and the two motor controllers may be connected to each other through CAN communication or the like. The two motor controllers may be configured as a master motor controller and a slave motor controller under the configuration of the main control unit in the pitch drive. The main motor controller may include a master speed control unit for outputting a master given current instruction, and the slave motor controller may include a slave speed control unit for outputting a slave given current instruction. Correspondingly, the motor controlled by the main motor controller is the master motor, and the motor controlled by the slave motor controller is the slave motor. In this embodiment, a frequency compensation unit may also be provided in the pitch drive, and the frequency compensation unit may be connected to the master speed control unit and the slave speed control unit, respectively.

[0059] The host controller may include at least a master speed control unit, which may perform a subtraction operation on the connected master given frequency command and the feedback frequency command of the master motor through a subtraction module to obtain the frequency deviation of the master motor, i.e., the master frequency deviation command, and may output the master frequency deviation command to the speed loop module, so as to output the torque command (current command) after the speed loop module performs speed closed-loop processing such as proportional and integral control, i.e., the master given current command to the frequency compensation unit and the master current control unit. The slave controller may include at least a slave speed control unit, which may perform a subtraction operation on the connected slave given frequency command and the feedback frequency command of the slave motor through a subtraction module to obtain the frequency deviation of the slave motor, i.e., the slave frequency deviation command, and may output the slave frequency deviation command to the speed loop module, so as to output the torque command (current command) after the speed loop module performs speed closed-loop processing such as proportional and integral control, i.e., the slave given current command to the frequency compensation unit and the slave current control unit.

[0060] Step S200: The frequency compensation unit generates a frequency compensation instruction according to the received master given current instruction and slave given current instruction, and outputs the frequency compensation instruction to the slave speed control unit;

[0061] When the pitch drive system encounters a sudden change in working conditions, which makes the working conditions corresponding to the two gears different, the speed characteristics of the master and slave motors will be reflected in their respective feedback frequencies. For example, the motor feedback frequency command corresponding to the unloaded gear will be much higher than the motor feedback frequency command corresponding to the normal working condition gear; the motor feedback speed corresponding to the overloaded gear will be much lower than the motor feedback speed under the normal working condition of the gear. Therefore, the inconsistent master and slave given current commands generated according to the abnormal master and slave feedback current commands during the sudden change in working conditions, and then the master and slave motors are controlled separately, which is the main reason for the poor transient response and steady-state response of the dual-motor pitch drive.

[0062] The present application scheme sets a frequency compensation unit to respectively access the main given current command and the slave given current command. The frequency compensation unit can calculate the connected main given current command and the slave given current command accordingly, determine the torque difference between the slave motor torque and the master motor torque according to the calculation result, and can further convert the torque difference into a corresponding frequency command, that is, a frequency compensation command, and then output it to the slave speed control unit to perform speed compensation on the slave speed control unit.

[0063] Step S300: The slave speed control unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, and outputs a slave given current instruction according to the compensated slave frequency deviation instruction.

[0064] The slave speed control unit can adjust the slave frequency deviation instruction generated by itself according to the received frequency compensation instruction, so that the adjusted slave frequency deviation instruction can be increased or decreased accordingly, and the adjusted frequency deviation instruction can be output to the speed loop module as the compensated slave frequency deviation instruction, so as to be converted into a new slave given current instruction by the speed loop module and then output to the frequency compensation unit and the slave current control unit. The slave current control unit can perform subtraction calculation on the received slave given current instruction and the slave feedback current instruction output from the motor feedback to obtain the slave current deviation instruction, and can convert the slave current deviation instruction into a corresponding PMW signal through the current loop module and then output it to the slave motor drive circuit, so that the slave motor drive circuit can output the corresponding alternating current to the slave motor, thereby realizing the control of the slave motor operation. At this time, the frequency compensation unit still determines that there is a torque difference between the slave motor torque and the master motor torque according to the calculation results of the new slave given current instruction and the master given current instruction, and repeats the above steps until it is determined that there is no torque difference between the slave motor torque and the master motor torque, that is, the slave motor torque is the same as the master motor torque, that is, the new slave given current instruction is equal to the master given current instruction.

[0065] In this way, the torque and speed of the slave motor can always be kept consistent with those of the main motor, so that when encountering sudden working conditions, the dual-motor variable pitch drive system can operate smoothly and without impact in transient response and steady-state response, thus avoiding the impact and vibration caused by sudden working conditions, thereby solving the problem of poor transient response and steady-state response of the dual-motor variable pitch drive, and can also effectively improve the service life and reliability of the wind turbine.

[0066] Reference Figures 1 to 4 In one embodiment, in step S200, the frequency compensation unit generates a frequency compensation instruction according to the received main given current instruction and the slave given current instruction, specifically:

[0067] The frequency compensation unit performs a subtraction operation on the main given current instruction and the slave given current instruction, and generates a frequency compensation instruction according to the subtraction result.

[0068] In this embodiment, the frequency compensation unit may include a subtraction module and a frequency compensation generation module. The subtraction module may be connected to the main given current instruction and the slave given current instruction respectively, and is used to output the subtraction calculation result representing the difference between the main motor torque and the slave motor torque obtained by subtracting the two to the frequency compensation generation module; the frequency compensation generation module may be pre-stored with a corresponding PI algorithm to generate and output the corresponding frequency compensation instruction to the slave speed control unit according to the subtraction calculation result, so as to realize frequency compensation for the slave frequency deviation instruction.

[0069] Reference Figures 1 to 4 In one embodiment, in step S300, the slave position speed unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, specifically:

[0070] The slave speed control unit performs addition calculation on the received frequency compensation instruction and the generated slave frequency deviation instruction, and uses the addition result as the compensated slave frequency deviation instruction.

[0071] In this embodiment, the slave speed control unit may include a subtraction module, an addition module and a speed loop module connected in sequence. Among them, the subtraction module can be used to generate a slave frequency deviation instruction and output it to the addition module; the addition module is used to add the connected slave frequency deviation instruction and the frequency compensation instruction, and the addition result can be output to the speed loop module as the compensated slave frequency deviation instruction. It should be noted that when the main given current instruction is greater than the slave given current instruction, the frequency compensation instruction can be regarded as a positive frequency instruction, so that the compensated slave frequency offset instruction can be greater than the slave frequency offset instruction before compensation; when the main given current instruction is less than the slave given current instruction, the frequency compensation instruction can be regarded as a negative frequency instruction, so that the compensated slave frequency offset instruction can be less than the slave frequency offset instruction before compensation; when the main given current instruction is equal to the slave given current instruction, the frequency compensation instruction can be regarded as a zero frequency instruction for adjustment, so that the compensated slave frequency offset instruction can be equal to the slave frequency offset instruction before compensation.

[0072] Reference Figures 1 to 4 In one embodiment, the master-slave motor driving method further includes:

[0073] Step 400, the frequency compensation unit further outputs a frequency compensation instruction to the main speed control unit;

[0074] In actual tests, it was found that it takes a certain amount of time to make the slave motor controller achieve the consistency of the torque of the master and slave motors through frequency compensation, which is not suitable for wind power generation scenarios where the wind resistance changes very quickly, such as at sea. In response to this problem, the master-slave motor driving method of the present application also enables the frequency compensation unit to send the generated frequency compensation instruction to the main speed control unit, so that the main motor controller can use the frequency compensation instruction to perform corresponding frequency compensation on the main motor at the same time.

[0075] Step 500: The main speed control unit performs frequency compensation on the generated main frequency deviation command according to the received frequency compensation command, and outputs a compensated main given current command to the main current control unit according to the compensated main frequency deviation command;

[0076] The main speed control unit can adjust the main frequency deviation command generated by itself according to the received frequency compensation command, so that the adjusted main frequency deviation command can be increased or decreased accordingly, and the adjusted frequency deviation command can be output to the speed loop module as the compensated main frequency deviation command, so as to be converted into a new main given current command by the speed loop module and then output to the frequency compensation unit and the main current control unit. At this time, the frequency compensation unit still determines that there is a torque difference between the main motor torque and the slave motor torque according to the calculation results of the new main given current command and the new slave given current command, and then repeats the above steps until it is determined that the new main given current command is equal to the new main given current command.

[0077] Step 600: The main current control unit controls the operation of the main motor according to the received main given current command and main feedback current command.

[0078] In this embodiment, the main current control unit can subtract the received main given current command and the main feedback current command output by the main motor feedback to obtain a main current deviation command, and can convert the main current deviation command into a corresponding PMW signal through the current loop module and then output it to the main motor drive circuit, so that the main motor drive circuit can output the corresponding AC power to the main motor, thereby controlling the operation of the main motor.

[0079] The master-slave motor driving method of the present invention performs frequency compensation on the master speed control unit and the slave speed control unit at the same time, so that when encountering sudden working conditions, the torque and speed of the master motor and the slave motor can quickly reach consistency, which is beneficial to improving the adaptability of the technical solution of the present invention to wind power generation scenarios with extremely fast wind resistance changes such as at sea.

[0080] Optionally, in step 500, the main speed control unit performs frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, specifically:

[0081] The main speed control unit performs subtraction calculation on the received frequency compensation instruction and the generated main frequency deviation instruction, and uses the subtraction result as the compensated main frequency deviation instruction.

[0082] In this embodiment, the main speed control unit may include two subtraction modules (hereinafter respectively represented by the first subtraction module and the second subtraction module) and a speed loop module connected in sequence. Among them, the first subtraction module can be used to generate a main frequency deviation instruction and output it to the second subtraction module; the second subtraction module is used to subtract the connected main frequency deviation instruction and the frequency compensation instruction, and the subtraction result can be output to the speed loop module as the compensated main frequency deviation instruction, thereby realizing frequency compensation of the main speed control unit. It should be noted that when the main given current instruction is greater than the main given current instruction, the compensated main frequency offset instruction may be greater than the main frequency offset instruction before compensation; when the main given current instruction is less than the main given current instruction, the compensated main frequency offset instruction may be less than the main frequency offset instruction before compensation; when the main given current instruction is equal to the main given current instruction, the compensated main frequency offset instruction may be equal to the main frequency offset instruction before compensation.

[0083] Reference Figures 1 to 4 In one embodiment, the master-slave motor driving method further includes:

[0084] Step S700: The main position control unit generates a main given frequency command according to the given position command and the feedback position command and outputs it to the main speed control unit.

[0085] In this embodiment, the main position control unit can obtain a given position instruction from the upper control device or upper control module, and can obtain a feedback position instruction from a position sensor such as an encoder in the main motor. The main position control unit can perform subtraction calculation on the given position instruction and the feedback position instruction through the subtraction module, output the subtraction result to the position loop module to multiply the position gain, and output the multiplication result as the main given frequency instruction to the main speed control unit, thereby realizing the position closed-loop control of the main motor.

[0086] Optionally, the master-slave motor driving method further includes:

[0087] Step S800: The master position control unit further outputs the generated master given frequency instruction as a slave given frequency instruction to the slave speed control unit.

[0088] In this embodiment, the slave motor controller adopts a position loop-free design. The slave motor controller is used to access the master given frequency instruction from the master motor controller to output it as a slave given frequency instruction to the slave speed control unit, thereby realizing the speed closed-loop control of the slave motor. Such a setting is conducive to improving the consistency of the master motor and the slave motor.

[0089] The present invention also proposes a variable pitch drive, which includes: a master motor controller 10, a slave motor controller 20 and a frequency compensation unit 30. The variable pitch drive is used to implement the above-mentioned master-slave motor driving method. The specific steps of the master-slave motor driving method refer to the above-mentioned embodiments. Since the variable pitch drive adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be repeated here one by one.

[0090] Among them, the main motor controller 10 includes: a main speed control unit 11, the main speed control unit 11 is used to output a main given current instruction; the slave motor controller 20 includes: a slave speed control unit 21, the slave speed control unit 21 is used to output a slave given current instruction; and a frequency compensation unit 30, the frequency compensation unit 30 is respectively connected to the main speed control unit 11 and the slave speed control unit 21 to access the main given current instruction and the slave given current instruction; the frequency compensation unit 30 is used to generate a frequency compensation instruction according to the received main given current instruction and the slave given current instruction, and output the frequency compensation instruction to the slave speed control unit 21, so that the slave speed control unit 21 performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction; the slave speed control unit 21 is also used to output a slave given current instruction to the slave current control unit 22 according to the compensated slave frequency deviation instruction. In one embodiment, the main motor controller 10 may further include a main speed control unit 11 and a main current control unit 12, and the slave motor controller 20 may further include a slave current control unit 22. The functions of the main speed control unit 11, the main current control unit and the slave current control unit 22 may also refer to the above embodiments and will not be elaborated here.

[0091] Optionally, the frequency compensation unit 30 includes:

[0092] A subtraction module 31, used for respectively accessing the main given current instruction and the slave given current instruction, and for performing subtraction calculation on the main given current instruction and the slave given current instruction, and outputting the subtraction calculation result;

[0093] The frequency compensation generating module 32 is used to receive the subtraction calculation result, and generate a corresponding frequency compensation instruction according to the subtraction calculation result and then output it to the slave speed control unit 21 .

[0094] Among them, the subtraction module 31 can be connected to the main given current instruction and the slave given current instruction respectively, and is used to output the subtraction calculation result of the difference between the torque of the main motor 40 and the torque of the slave motor 50 obtained by subtracting the two to the frequency compensation generation module 32; the frequency compensation generation module 32 can be pre-stored with a corresponding PI algorithm to generate and output the corresponding frequency compensation instruction to the slave speed control unit according to the subtraction calculation result, so as to achieve frequency compensation for the slave frequency deviation instruction. In another optional embodiment, the frequency compensation generation module 32 can also output the frequency compensation instruction to the main speed control unit 11 at the same time, so as to perform frequency compensation on the main speed control unit 11 and the slave speed control unit 21 at the same time.

[0095] Optionally, the frequency compensation unit 30 is further used to output a frequency compensation instruction to the main speed control unit 11;

[0096] The main speed control unit 11 is further used to perform frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, and output a main given current instruction according to the compensated main frequency deviation instruction.

[0097] The main speed control unit 11 can adjust the main frequency deviation command generated by itself according to the received frequency compensation command, so that the adjusted main frequency deviation command can be increased or decreased accordingly, and the adjusted frequency deviation command can be output to the speed loop module as the compensated main frequency deviation command, so as to be converted into a new main given current command by the speed loop module and then output to the frequency compensation unit 30 and the main current control unit 12. At this time, the frequency compensation unit 30 still determines that there is a torque difference between the torque of the main motor 40 and the torque of the slave motor 50 according to the calculation results of the new main given current command and the new slave given current command, and then repeats the above steps until it is determined that the new main given current command is equal to the new main given current command.

[0098] Optionally, the main motor controller 10 further includes:

[0099] The main current control unit 12 is used to control the operation of the main motor 40 according to the main given current command output by the main speed control unit 11 and the received main feedback current command.

[0100] The main current control unit 12 can subtract the received main given current instruction and the main feedback current instruction output by the main motor 40 to obtain a main current deviation instruction, and can convert the main current deviation instruction into a corresponding PMW signal through the current loop module and output it to the main motor drive circuit, so that the main motor drive circuit can output the corresponding alternating current to the main motor 40, thereby controlling the operation of the main motor 40.

[0101] Optionally, the slave motor controller 20 further includes:

[0102] The slave current control unit 22 is used to control the operation of the slave motor 50 according to the slave given current command output by the slave speed control unit 21 and the received slave feedback current command.

[0103] The slave current control unit 22 can subtract the received slave given current command and the slave feedback current command output from the motor 50 to obtain a slave current deviation command, and can convert the slave current deviation command into a corresponding PMW signal through the current loop module and output it to the slave electric drive circuit, so that the slave electric drive circuit can output the corresponding alternating current to the slave motor 50, thereby controlling the operation of the slave motor 50.

[0104] Optionally, the main motor controller 10 further includes:

[0105] The main position control unit 13 is used to generate a main given frequency command according to the received given position command and feedback position command, and output the command to the main speed control unit 11 .

[0106] The main position control unit 13 can obtain a given position instruction from a host control device or a host control module, and can obtain a feedback position instruction from a position sensor such as an encoder in the main motor 40. The main position control unit 13 can perform a subtraction calculation on the given position instruction and the feedback position instruction through a subtraction module, output the subtraction calculation result to the position loop module to multiply the position gain, and can output the multiplication calculation result as a main given frequency instruction to the main speed control unit 11, thereby realizing the position closed-loop control of the main motor 40.

[0107] Optionally, the master speed control unit 11 is further configured to output the generated master given frequency instruction as a slave given frequency instruction to the slave speed control unit 21 .

[0108] In this embodiment, the slave motor controller 20 adopts a position loop-free design. The slave motor controller 20 is used to access the master given frequency instruction from the master motor controller 10, so as to output it to the slave speed control unit 21 as a slave given frequency instruction, thereby realizing the speed closed-loop control of the slave motor 50. Such a setting is conducive to improving the consistency of the master motor 40 and the slave motor 50.

[0109] The present invention also proposes a variable pitch drive system, which includes a main motor, a slave motor and a variable pitch drive. The specific structure of the variable pitch drive refers to the above-mentioned embodiment. Since the variable pitch drive system adopts all the technical solutions of all the above-mentioned embodiments, it has at least all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0110] The pitch drive is connected to the main motor and the slave motor respectively, and the pitch drive is used to control the operation of the main motor and the slave motor respectively. Specifically, the pitch drive may also include a main motor drive circuit and a slave motor drive circuit. The main motor drive circuit may output corresponding alternating current to the main motor according to the PWM signal output by the main motor controller, so as to drive the main motor to drive the main reducer to work; the slave motor drive circuit may output corresponding alternating current to the slave motor according to the PWM signal output by the slave motor controller, so as to drive the slave motor to drive the slave reducer to work.

[0111] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A master-slave motor driving method, applied to a variable pitch drive, characterized in that: The pitch drive is connected to a main motor and a slave motor of a pitch drive system, the pitch drive includes a main motor controller, a slave motor controller and a frequency compensation unit, the main motor controller includes a main position control unit and a main speed control unit for outputting a main given current instruction, the slave motor controller includes a slave speed control unit for outputting a slave given current instruction, the frequency compensation unit is connected to the main speed control unit and the slave speed control unit respectively, and the master-slave motor driving method includes: The main speed control unit and the slave speed control unit respectively output a main given current command and a slave given current command to the frequency compensation unit; The frequency compensation unit generates a frequency compensation instruction according to the received master given current instruction and slave given current instruction, and outputs the frequency compensation instruction to the slave speed control unit; The master position control unit outputs a slave given frequency command to the slave speed control unit; The slave speed control unit generates a slave frequency deviation instruction according to the slave given frequency instruction and the feedback frequency instruction of the slave motor; The slave speed control unit performs frequency compensation on the generated slave frequency deviation instruction according to the received frequency compensation instruction, and outputs a slave given current instruction according to the compensated slave frequency deviation instruction; Wherein, outputting a slave given current instruction according to the compensated slave frequency deviation instruction comprises: The slave speed control unit outputs the compensated slave frequency deviation instruction to the speed loop module, so as to be converted into a new slave given current instruction by the speed loop module and then output to the frequency compensation unit and the slave current control unit; The method further comprises: The slave current control unit subtracts the received slave given current command from the slave feedback current command output from the motor feedback to obtain a slave current deviation command, and can convert the slave current deviation command through the current loop module and output a corresponding signal to the slave motor drive circuit, so that the slave motor drive circuit can output corresponding alternating current to the slave motor.

2. The master-slave motor driving method according to claim 1, characterized in that: The frequency compensation unit generates a frequency compensation instruction according to the received main given current instruction and the slave given current instruction, specifically: The frequency compensation unit performs a subtraction operation on the main given current instruction and the slave given current instruction, and generates a frequency compensation instruction according to the subtraction result.

3. The master-slave motor driving method according to claim 1, characterized in that: The slave position and speed unit performs frequency compensation on the generated slave frequency deviation command according to the received frequency compensation command, specifically: The slave position control unit performs addition calculation on the received frequency compensation instruction and the generated slave frequency deviation instruction, and uses the addition result as the compensated slave frequency deviation instruction.

4. The master-slave motor driving method according to claim 1, characterized in that: The master-slave motor driving method further includes: The frequency compensation unit also outputs a frequency compensation instruction to the main speed control unit; The main speed control unit performs frequency compensation on the generated main frequency deviation command according to the received frequency compensation command, and outputs the main given current command to the main current control unit according to the compensated main frequency deviation command; The main current control unit controls the operation of the main motor according to the received main given current command and main feedback current command.

5. The master-slave motor driving method according to claim 4, characterized in that: The main speed control unit performs frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, specifically: The main speed control unit performs subtraction calculation on the received frequency compensation instruction and the generated main frequency deviation instruction, and uses the subtraction result as the compensated main frequency deviation instruction.

6. The master-slave motor driving method according to any one of claims 1 to 5, characterized in that: The master-slave motor driving method further includes: The main position control unit generates a main given frequency command according to the given position command and the feedback position command and outputs it to the main speed control unit.

7. The master-slave motor driving method according to claim 6, characterized in that: The master-slave motor driving method further includes: The master position control unit also outputs the generated master given frequency command as a slave given frequency command to the slave speed control unit.

8. A variable pitch drive, used to implement the master-slave motor driving method according to any one of claims 1 to 7, characterized in that: The pitch drive is connected to the main motor and the slave motor of the pitch drive system, and the pitch drive comprises: The main motor controller includes: a main speed control unit, the main speed control unit is used to output a main given current instruction; a main position control unit, the main position control unit is used to output a slave given frequency instruction; The slave motor controller comprises: a slave speed control unit, the slave speed control unit is used to output a slave given current instruction, and generate a slave frequency deviation instruction according to the slave given frequency instruction output by the master position control unit and the feedback frequency instruction of the slave motor; a slave current control unit, the slave current control unit is used to control the operation of the slave motor according to the slave given current instruction output by the slave speed control unit and the received slave feedback current instruction; and, A frequency compensation unit, the frequency compensation unit is connected to the master speed control unit and the slave speed control unit respectively to access the master given current command and the slave given current command; the frequency compensation unit is used to generate a frequency compensation command according to the received master given current command and the slave given current command, and output the frequency compensation command to the slave speed control unit, so that the slave speed control unit performs frequency compensation on the generated slave frequency deviation command according to the received frequency compensation command; The slave speed control unit is further configured to output a slave given current command to the slave current control unit according to the compensated slave frequency deviation command.

9. The pitch drive according to claim 8, characterized in that: The frequency compensation unit comprises: A subtraction module, used for respectively accessing the main given current instruction and the slave given current instruction, and for performing a subtraction calculation on the main given current instruction and the slave given current instruction, and outputting a calculation result; The frequency compensation generating module is used to access the calculation result of the subtraction module, and generate a corresponding frequency compensation instruction according to the calculation result of the subtraction module and then output it to the slave speed control unit.

10. The pitch drive according to claim 8, characterized in that: The frequency compensation unit is also used to output a frequency compensation instruction to the main speed control unit; The main speed control unit is also used to perform frequency compensation on the generated main frequency deviation instruction according to the received frequency compensation instruction, and output a main given current instruction according to the compensated main frequency deviation instruction.

11. The pitch drive according to claim 8, characterized in that: The main motor controller also includes: The main current control unit is used to control the operation of the main motor according to the main given current command output by the main speed control unit and the main feedback current command received.

12. The pitch drive according to any one of claims 8 to 11, characterized in that: The main motor controller also includes: The main speed control unit is used to generate a main given frequency command according to the received given position command and feedback position command and output the command to the main speed control unit.

13. The pitch drive according to claim 12, characterized in that The master speed control unit is further configured to output the generated master given frequency instruction as a slave given frequency instruction to the slave speed control unit.

14. A variable pitch drive system, characterized in that: The pitch drive system comprises: Main motor; from the motor; and, The pitch drive according to any one of claims 8 to 13, wherein the pitch drive is connected to the main motor and the slave motor, respectively, and the pitch drive is used to control the operation of the main motor and the slave motor, respectively.

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