CN213879372U - Pitch system - Google Patents

Abstract

The application relates to a pitch system, which comprises a power supply module, a power supply assembly, a driver, a backup power supply and a pitch motor. The alternating current input end of the power supply assembly is connected with the alternating current power supply end of the power supply module, and the direct current output end of the power supply assembly is connected with the backup power supply and the driver; the driver is connected with a variable pitch motor. The power supply assembly is used for rectifying the alternating current output by the power supply module to obtain direct current to charge a standby power supply and supplying power to the variable pitch motor through the driver; the backup power supply is used for supplying power to the variable pitch motor through the driver when the required variable pitch power of the variable pitch motor is larger than a preset power threshold. According to the pitch control system, when the load borne by the pitch control motor is large and the corresponding pitch control required power is larger than the preset power threshold value, the backup power supply supplies power. Therefore, the influence of the sudden change of the side load of the variable pitch motor on the power supply module is equivalently isolated, so that the power requirement of the variable pitch motor on the power supply module is reduced, and the circuit cost is favorably reduced.

Description

Pitch system

Technical Field

The application relates to the technical field of wind power generation, in particular to a variable pitch system.

Background

The variable pitch system is one of core parts of a control system of the wind generating set, and plays an important role in safe, stable and efficient operation of the set. The stable pitch control becomes one of the hot spots and difficulties of the current large-scale wind generating set control technology research.

The traditional pitch control system comprises a power supply module, a driver, a backup power supply and a charger. When the power supply module is in a normal power supply state, the charger charges the backup power supply, and the driver is connected to the power supply module and provides electric energy for the variable-pitch motor; when the power supply module breaks down, the standby power supply supplies power to the variable pitch motor through the driver in an emergency mode, and the blades are driven to complete emergency safe blade retracting actions. The load borne by the variable pitch motor changes along with the change of the external wind speed, and the required power of the variable pitch motor changes along with the change of the load, so that the variable pitch motor is applicable to the wind power generation. The traditional pitch control system needs the power of the power supply module to be matched with the load of the corresponding pitch control motor, and the full-power requirement of the action of the pitch control motor is met. Therefore, the traditional pitch system has the defect of high circuit cost.

SUMMERY OF THE UTILITY MODEL

Based on this, there is a need for a low cost pitch system.

A variable pitch system comprises a power supply module, a power supply assembly, a driver, a backup power supply and a variable pitch motor;

the alternating current input end of the power supply assembly is connected with the alternating current power supply end of the power supply module, and the direct current output end of the power supply assembly is connected with the backup power supply and the driver; the driver is connected with the variable pitch motor;

the power supply assembly is used for rectifying alternating current output by the power supply module to obtain direct current to charge the backup power supply and supplying power to the variable pitch motor through the driver; the backup power supply is used for supplying power to the variable pitch motor through the driver when the required variable pitch power of the variable pitch motor is larger than a preset power threshold.

In one embodiment, the driver is a bidirectional AC/DC conversion circuit.

In one embodiment, the power supply assembly comprises a rectifying unit and an energy storage unit; the input end of the rectifying unit is connected with the alternating current power supply end of the power supply module; the output end of the rectifying unit is connected with the energy storage unit, the driver and the backup power supply.

In one embodiment, the power supply assembly further comprises a current-limiting and voltage-limiting unit, and the rectifying unit is connected with the backup power supply and the driver through the current-limiting and voltage-limiting unit.

In one embodiment, the driver comprises an energy storage component and an inverter component; one end of the energy storage assembly is connected with the direct current output end of the power supply assembly; the other end of the energy storage assembly is connected with the direct current end of the inversion assembly, and the alternating current end of the inversion assembly is connected with the variable pitch motor.

In one embodiment, the dc output of the power supply assembly is connected to the backup power supply via the energy storage unit of the driver.

In one embodiment, the backup power source is a super capacitor.

In one embodiment, the system further comprises a bidirectional charger, wherein one end of the bidirectional charger is connected with the driver, and the other end of the bidirectional charger is connected with the backup power supply.

In one embodiment, the number of the pitch motors is more than two, and the number of the power supply assembly, the driver and the backup power supply is the same as that of the pitch motors; the power supply assembly, the backup power supply and the variable pitch motor are respectively and correspondingly connected with the driver.

In one embodiment, the number of the pitch motors is more than two, the number of the power supply assemblies is one, and the number of the drivers and the backup power supplies is the same as that of the pitch motors; the power supply assembly is connected with each driver, and the backup power supply and the variable pitch motor are respectively and correspondingly connected with the drivers.

According to the pitch system, the power supply assembly is arranged between the power supply module and the driver, the power supply assembly is connected to the alternating current power supply end of the power supply module, alternating current output by the power supply module is rectified and then is charged to the backup power supply, and the driver is used for supplying power to the pitch motor; and when the required variable-pitch power of the variable-pitch motor is greater than a preset power threshold value, the backup power supply supplies power to the variable-pitch motor through the driver. Namely, when the load borne by the variable pitch motor is large and the corresponding variable pitch required power is larger than the preset power threshold, the backup power supply supplies power. Therefore, the influence of the sudden change of the side load of the variable pitch motor on the power supply module is equivalently isolated, so that the power requirement of the variable pitch motor on the power supply module is reduced, and the circuit cost is favorably reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of the components of a pitch system of an embodiment;

FIG. 2 is a block diagram of the components of another embodiment of a pitch system;

FIG. 3 is a block diagram of a three-blade pitch system;

FIG. 4 is a block diagram of another three-blade pitch system.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Embodiments of the present application are set forth in the accompanying drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

It will be understood that, as used herein, the terms "first," "second," and the like may be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish one element from another. For example, a first resistance may be referred to as a second resistance, and similarly, a second resistance may be referred to as a first resistance, without departing from the scope of the present application. The first resistance and the second resistance are both resistances, but they are not the same resistance.

It is to be understood that "connection" in the following embodiments is to be understood as "electrical connection", "communication connection", and the like if the connected circuits, modules, units, and the like have communication of electrical signals or data with each other.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises/comprising," "includes" or "including," etc., specify the presence of stated features, integers, steps, operations, components, parts, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

In one embodiment, referring to fig. 1, a pitch system is provided, assembled in a hub of a wind turbine generator system, cooperating with a main controller and a fan main system. The main controller and the variable pitch system are connected with the fan main system through the slip ring, and the main controller is connected with the variable pitch system. The pitch system comprises a power supply module 100, a power supply assembly 200, a driver 300, a backup power supply 400 and a pitch motor 500. The alternating current input end of the power supply module 200 is connected with the alternating current power supply end of the power supply module 100, and the direct current output end of the power supply module 200 is connected with the backup power supply 400 and the driver 300; the drive 300 is connected to a pitch motor 500. The power supply assembly 200 is configured to rectify the ac power output by the power supply module 100 to obtain dc power to charge the backup power supply 400, and to supply power to the pitch motor 500 through the driver 300; the backup power supply 400 is used for supplying power to the pitch motor 500 through the driver 300 when the pitch required power of the pitch motor 500 is larger than a preset power threshold.

The power supply module 100 refers to a front-end power supply system of the power supply module 200 in the pitch system, and the power supply module 100 is used for connecting an external power supply to the power supply module 200. The power module 200 includes a rectifying unit for converting ac power input by the power module 100 into dc power and inputting the dc power to the driver 300, and the driver 300 includes an inverter module for converting dc power into ac power and outputting the ac power to the pitch motor 500, so as to supply power to the pitch motor 500. The backup power source 400 includes an energy storage element, which may be an energy storage capacitor, an energy storage battery, or other types of electronic elements that can perform an energy storage function. Further, when the backup power source 400 protects the energy storage battery, the energy storage battery may be a lead-acid battery or a lithium battery. Further, the driver 300 may be connected to the power supply module 200 through a dc bus, and the standby power supply 400 may be connected to the dc bus of the driver 300.

Specifically, when the pitch system is powered on, the power supply module 200 rectifies the ac power output by the power supply module 100, and then inputs the rectified dc power to the backup power supply 400 to charge the backup power supply 400. After the backup power supply 400 is charged, the common terminal between the backup power supply 400 and the power supply module 200 maintains a certain electrical parameter value determined by the circuit configuration of the backup power supply 400. At this time, both the drive 300 and the pitch motor 500 are in a standby state.

When the main controller sends a pitch instruction to the pitch system, the pitch motor 500 needs to perform pitch control according to the pitch instruction, at this time, the direct current obtained by rectification of the power supply assembly 200 is input into the driver 300, and the direct current is converted into alternating current through the driver 300 to supply power to the pitch motor 500. When the variable pitch motor 500 executes actions, the borne load is related to the external wind speed, and the energy taking size is correspondingly different. When the power supply module 200 supplies power to the pitch motor 500, the variation of the electrical parameter of the dc output terminal of the power supply module 200 is directly related to the energy extraction of the pitch motor 500. Then, when the loads borne by the pitch control motor 500 are different, the pitch control system will have different working modes according to the magnitude relationship between the electrical parameter value of the dc output end of the power supply module 200 and the electrical parameter value of the backup power supply 400. When the load borne by pitch motor 500 is small and the corresponding pitch required power is less than or equal to the preset power threshold, power supply assembly 200 supplies power to pitch motor 500, and simultaneously, the dc output end of power supply assembly 200 can maintain the same electrical parameter value as that of backup power supply 400, and at this time, power supply assembly 200 alone supplies power to pitch motor 500.

When the load borne by the pitch motor 500 is large and the corresponding pitch required power is greater than the preset power threshold, the power supply assembly 200 cannot maintain the same electrical parameter value as the backup power supply 400 while supplying power to the pitch motor 500, and at this time, the backup power supply 400 supplies power to the pitch motor 500 through the driver 300 to meet the power requirement of the pitch motor 500 until the pitch action is completed or the electrical parameter value of the dc output end of the power supply assembly 200 is equal to that of the backup power supply 400. After the pitch variation operation is completed, the power supply module 200 inputs the rectified dc power to the backup power supply 400, and charges the backup power supply 400. It will be appreciated that the predetermined power threshold described above is not a definite value, and is related to the real-time loading state of the pitch system and the specific circuit configuration of power supply assembly 200 and backup power supply 400.

For ease of understanding, the following description will be given taking a case where the electrical parameter is a voltage as an example. As described above, when power module 200 supplies power to pitch motor 500, the voltage drop at the DC output of power module 200 is directly related to the amount of energy extracted by pitch motor 500. That is to say, when the loads borne by pitch motor 500 are different, the pitch system will have different operating modes according to the magnitude relationship between the voltage value of the dc output terminal of power supply module 200 and the voltage value of backup power supply 400.

Specifically, when the load borne by pitch motor 500 is small, power supply assembly 200 can supply power to pitch motor 500, and the voltage value of the dc output terminal of power supply assembly 200 can be kept larger than the voltage value of backup power supply 400. At this time, while power supply assembly 200 supplies power to pitch motor 500, power supply assembly continues to charge backup power supply 400 until backup power supply 400 is fully charged, or the voltage value of the dc output terminal of power supply assembly 200 is equal to that of backup power supply 400. When the load borne by the pitch-variable motor 500 is large and the voltage value of the direct-current output end of the power supply assembly 200 is smaller than the voltage value of the backup power supply 400, the backup power supply 400 supplies power to the pitch-variable motor 500 through the driver 300 until the pitch-variable action is completed, or the voltage value of the direct-current output end of the power supply assembly 200 is equal to that of the backup power supply 400, and after the pitch-variable action is completed, the direct current obtained after rectification is input into the backup power supply 400 through the power supply assembly 200 to charge the backup power supply 400.

Further, backup power supply 400 is also used to provide power to pitch motor 500 through driver 300 when power module 100 is powered down or power assembly 200 fails without output.

In the pitch system, the power supply module 200 is arranged between the power supply module 100 and the driver 300, the power supply module 200 is connected to an alternating current power supply end of the power supply module 100, rectifies alternating current output by the power supply module 100 and then charges a backup power supply 400, and supplies power to the pitch motor 500 through the driver 300; when the required variable-pitch power of the variable-pitch motor 500 is larger than the preset power threshold, the backup power supply 400 supplies power to the variable-pitch motor 500 through the driver. That is, when the load borne by the pitch motor 500 is large and the corresponding pitch required power is greater than the preset power threshold, the backup power supply 400 supplies power. Therefore, the influence of the sudden load change at the side of the variable pitch motor 500 on the power supply module 100 and the front-end equipment such as the slip ring is equivalently isolated, so that the power requirement of the variable pitch motor 500 on the power supply module 100 is reduced, the power requirement of the front-end equipment such as the slip ring is also reduced, and the circuit cost is favorably reduced. In addition, due to the fact that the backup power source 400 is arranged, when the load is large, the backup power source 400 supplies power to the variable pitch motor 500, an independent energy storage loop does not need to be designed, the hybrid function is achieved, the high-power output requirement of the load side on the power supply assembly 200 is isolated, and the reduction of the circuit cost of the variable pitch system is facilitated.

Further, in one embodiment, the driver 300 is a bidirectional AC/DC conversion circuit, and when the input terminal is a DC terminal, the input DC power can be converted into AC power and output from the AC terminal; when the input end is an alternating current end, the input alternating current can be converted into direct current to be output from a direct current end.

It can be understood that when the power demand of the pitch motor 500 is large, the backup power supply 400 supplies power to the pitch motor 500, which results in the reduction of the stored energy of the backup power supply 400. When an external circuit fails, the backup power supply 400 meets the instantaneous power requirement of the pitch motor 500, which also results in a reduction in the stored energy of the backup power supply 400. Then, when the pitch motor 500 is in a power generation state and the backup power supply 400 is in an incompletely charged state, the alternating current fed back by the pitch motor 500 is converted into direct current through the driver 300 and then reaches the backup power supply 400 to charge the backup power supply 400, so that the electric quantity of the backup power supply 400 is kept sufficient, and on one hand, the charging efficiency of the backup power supply 400 is improved, the loss of a pitch system is reduced, and energy is saved; on the other hand, the risk resistance of the pitch system is improved.

In one embodiment, referring to fig. 2, the power module 200 includes a rectifying unit 210 and an energy storage unit 220. Wherein, the input end of the rectifying unit 210 is connected to the ac power supply end of the power supply module 100; the output end of the rectifying unit 210 is connected to the energy storage unit 220, the driver 300 and the backup power supply 400.

The rectifying unit 210 is composed of rectifying diodes, and the voltage passing through the rectifying circuit is not an alternating voltage but a unidirectional pulsating direct current voltage. Specifically, the rectifying unit 210 may be a half-wave rectifying circuit, a full-wave rectifying circuit, a bridge rectifying circuit, a voltage-doubler rectifying circuit, or the like. In summary, the present embodiment does not limit the type and specific device configuration of the rectifying unit 210. The energy storage unit 220 may be an energy storage capacitor, an energy storage battery, or other electronic components with an energy storage function, and in short, the specific component configuration of the energy storage unit 220 is not limited in this embodiment.

Specifically, when the pitch system is powered on, the rectifying unit 210 rectifies the alternating current output by the power supply module 100, and then inputs the rectified direct current into the energy storage unit 220 and the backup power supply 400 to charge the energy storage unit 220 and the backup power supply 400. When the main controller sends a pitch instruction to the pitch system, the pitch motor 500 needs to perform pitch control according to the pitch instruction, at this time, the rectification unit 210 supplies power to the pitch motor 500, and the voltage drop of the direct current side of the rectification unit 210 is directly related to the energy taking size of the pitch motor 500. Then, when the loads borne by the pitch motor 500 are different, the pitch system will have different working modes according to the magnitude relationship between the voltage value of the rectifying unit 210 and the voltage value of the backup power supply 400.

When the load borne by the pitch motor 500 is small and the corresponding pitch required power is less than or equal to the preset power threshold, and the rectification unit 210 supplies power to the pitch motor 500, the power supply module 100 continuously supplies power to the rectification unit 210, so that the direct current side of the rectification unit 210 maintains the same voltage value as the backup power supply 400, and at the moment, the rectification unit 210 independently supplies power to the pitch motor 500.

When the load borne by the pitch motor 500 is large and the corresponding pitch required power is greater than the preset power threshold, and the rectifying unit 210 supplies power to the pitch motor 500, the power supply module 100 continuously supplies power to the rectifying unit 210, so that the direct current side of the rectifying unit 210 cannot maintain the same voltage value as that of the backup power supply 400, at this time, the backup power supply 400 supplies power to the pitch motor 500 through the driver 300 to meet the power requirement of the pitch motor 500 until the pitch action is completed, or the voltage value of the direct current side of the rectifying unit 210 is equal to that of the backup power supply 400. Similarly, the preset power threshold is not a definite value, and the preset power threshold is related to the real-time load state of the pitch system and the specific circuit configuration of the rectifying unit 210, the energy storage unit 220 and the backup power supply 400. Further, when the power supply module 100 fails and cannot continuously output alternating current to the rectifying unit, the energy storage unit 220 cooperates with the backup power supply 400 to emergently supply power to the pitch control motor 500, so that safety accidents caused by the failure of the power supply module 100 can be avoided, and the risk resistance of the pitch control system can be improved.

In one embodiment, referring to fig. 2, the power module 200 further includes a current limiting unit 230, and the rectifying unit 210 is connected to the backup power source and the driver through the current limiting unit 230.

After passing through the current-limiting voltage-limiting unit 230 of the power supply module 200, the electrical signal is output from the dc output terminal of the power supply module 200, at this time, the current of the dc output terminal is always smaller than or equal to the preset current value, and the voltage is always smaller than or equal to the preset voltage value. Specifically, the current-limiting and voltage-limiting unit 230 may include a voltage feedback circuit and a current feedback circuit, and the switching frequency and the conduction time of the switching tube are adjusted in real time through the voltage feedback circuit and the current feedback circuit, so as to achieve the current-limiting and voltage-limiting effect. The current-limiting voltage-limiting unit 230 may also include a current detection unit, a voltage detection unit, and a control chip, and performs overcurrent and overvoltage protection by detecting the output current and the output voltage, and sending the detection result to the control chip, and then outputting a corresponding instruction by the control chip according to the detection result. In short, in this embodiment, the specific circuit structure adopted by the current-limiting and voltage-limiting unit 230 in the power module 200 is not limited.

In the above embodiment, the current-limiting and voltage-limiting unit 230 is disposed in the power supply assembly 200, so that the dc output of the power supply assembly 200 is the current-limiting and voltage-limiting output, which is equivalent to that the power supply assembly 200 keeps operating at a low power, and the influence of sudden load change at the side of the pitch motor 500 on the power supply module 100 and the front-end devices such as the slip ring is effectively isolated, so that the power requirement of the pitch motor 500 on the power supply module 100 and the front-end devices such as the slip ring is reduced, and the circuit cost of the pitch system is reduced.

In one embodiment, with continued reference to fig. 2, the driver 300 includes an energy storage component 310 and an inverter component 320. One end of the energy storage component 310 is connected to the dc output end of the power supply component 200; the other end of the energy storage assembly 310 is connected to the dc end of the inverter assembly 320, and the ac end of the inverter assembly 320 is connected to the pitch motor 500.

The energy storage component 310 may be an energy storage capacitor, an energy storage battery, or other electronic components with an energy storage function, and further, when the energy storage battery is protected by the backup power supply 400, the energy storage battery may be a lead-acid battery or a lithium battery. In summary, the present embodiment does not limit the specific device configuration of the energy storage assembly 310. The inverter component 320 may be a fully-controlled inverter circuit composed of fully-controlled devices with self-turn-off capability, or may be a semi-controlled inverter circuit composed of semi-controlled devices (such as ordinary thyristors) without turn-off capability. In short, the present embodiment does not limit the specific device structure of the inverter module 320.

Specifically, the dc power output by the power module 200 may be stored in the energy storage module 310 of the driver 300. When the pitch control motor 500 needs to perform pitch control according to the pitch control command, the energy storage assembly 310 outputs direct current to the direct current end of the inverter assembly 320, the inverter assembly 320 converts the direct current into alternating current, and the alternating current output by the inverter assembly 320 outputs the alternating current to the pitch control motor 500 to supply power to the pitch control motor 500.

Further, in one embodiment, the inverter component 320 is a bidirectional AC/DC conversion circuit, and when the input terminal is a DC terminal, it can convert the input DC power into AC power and output the AC power from the AC terminal; when the input end is an alternating current end, the input alternating current can be converted into direct current to be output from a direct current end. Specifically, when the pitch motor 500 performs a pitch operation, the direct current input by the power supply assembly 200 is converted into an alternating current by the inverter assembly 320, and then is output to the pitch motor 500, so as to provide electric energy for the pitch motor 500; when the paddle motor 500 is in a power generation state, the fed-back ac power is converted into dc power by the rectifying unit of the inverter assembly 320, and then reaches the backup power supply 400 to charge the backup power supply 400.

In the above embodiment, the driver 300 includes the energy storage component 310 and the inverter component 320, which can realize energy storage and inverter functions, when the power supply module 100 fails, and ac cannot be continuously output to the driver 300 through the power supply component 200, or when the power supply component 200 fails and has no output, the energy storage component 310 cooperates with the backup power supply 400 to provide emergency power to the pitch motor 500, so that safety accidents caused by the failure of the power supply module 100 can be avoided, and the risk resistance of the pitch system can be improved.

In one embodiment, the dc output of the power supply assembly is connected to a backup power supply via the energy storage assembly of the driver.

Specifically, the direct current output by the power supply assembly can be stored in an energy storage assembly of the driver, and then the energy storage assembly charges the backup power supply. When the load born by the variable pitch motor is large and a backup power supply is needed to supplement energy supply, the backup power supply provides direct current to the inversion assembly through the energy storage assembly, and the inversion assembly converts the direct current into alternating current to supply energy to the variable pitch motor.

In one embodiment, the backup power source is a super capacitor. The super capacitor is an electrochemical capacitor for storing energy through a polarized electrolyte. The energy storage device is different from a traditional chemical power source, is a power source which is arranged between a traditional capacitor and a battery and has special performance, and the energy storage process does not generate chemical reaction. The super capacitor comprises a positive electrode and a negative electrode, a diaphragm is arranged between the two electrodes, and a pore separated by the two electrodes and the diaphragm is filled by electrolyte. The super capacitor includes an electric double layer capacitor and a faraday quasi-capacitor according to the energy storage mechanism. Further, the backup power supply may be a super capacitor, or may be formed by connecting a plurality of super capacitors in parallel, and in short, the present embodiment does not limit the type, number, and specific connection manner of the super capacitors in the backup power supply.

In the above embodiment, the super capacitor is used as the backup power supply, and the super capacitor has the advantages of high charging speed, long cycle service life, strong heavy current discharging capability, high safety factor and the like, so that the performance of the pitch system is favorably improved.

In one embodiment, with continued reference to fig. 2, the pitch system further includes a bidirectional charger 600, wherein one end of the bidirectional charger 600 is connected to the driver 300, and the other end is connected to the backup power source 400.

The bidirectional charger 600 is a charger that can change the direction of current as required to realize bidirectional energy transfer. Specifically, when the power supply module 100 supplies power normally, the bidirectional charger 600 charges the backup power supply 400; when the power supply module 100 fails and cannot supply power continuously, the bidirectional charger 600 switches the working mode to realize the deep discharge function of the backup power supply 400, and the driver 300 supplies power to the variable pitch motor 600. Further, the bidirectional charger 600 may also monitor the service life of the backup power supply 400 according to the charging and discharging current and time of the backup power supply 400 in different working modes.

In the above embodiment, the bidirectional charger 600 is provided, so that bidirectional transfer of energy can be realized, and the bidirectional charger has the advantages of high efficiency, small size, good dynamic performance, low cost and the like, so that the size of the backup power supply 400 can be effectively reduced, and in addition, the bidirectional charger 600 can be used for improving the voltage, so that the energy of the super capacitor can be fully utilized, and the power supply performance of the pitch control system is enhanced.

In one embodiment, the number of the pitch motors is more than two, and the number of the power supply assembly, the driver and the backup power supply is the same as that of the pitch motors; the power supply assembly, the backup power supply and the variable pitch motor are respectively and correspondingly connected with the driver.

Specifically, the number of the pitch motors can be any number of more than two, and the pitch motors are arranged according to actual needs. Referring to fig. 3, a block diagram of a three-blade pitch system is provided, where the three-blade pitch system includes three pitch motors, and the three pitch motors respectively control corresponding blades and execute pitch control actions. Specifically, the three-blade pitch control system comprises a power supply module, three power supply assemblies, three drivers and three backup power supplies. The ac power output by the power supply module 100 is divided into three paths, and the three paths are connected to the first power supply module 201, the second power supply module 202, and the third power supply module 203, respectively. The first power supply assembly 201 is connected with a first pitch motor 501 through a first driver 301, and the first power supply assembly 201 is further connected with a first backup power supply 401; second power supply assembly 202 is connected to second pitch motor 502 via second driver 302, and second power supply assembly 202 is also connected to second backup power source 402; the third power supply assembly 203 is connected to a third pitch motor 503 via a third driver 303, and the third power supply assembly 203 is further connected to a third backup power supply 403.

When the system is powered on, alternating current output by the power supply module 100 is rectified by the power supply assembly and then respectively supplied to the corresponding backup power supplies. When the pitch control action is executed, according to the difference of the load borne by the corresponding pitch control motors, the backup power supply, the power supply assembly and the driver corresponding to each pitch control motor operate in different working modes, and the limitation of the specific working modes is referred to above and is not repeated herein. When the variable pitch motor is in a power generation state, the fed-back alternating current is converted into direct current through the corresponding driver, and then reaches the corresponding backup power supply to charge the corresponding backup power supply.

In the above embodiment, the independent power supply assembly, the standby power supply, the driver and the pitch control motor are adopted to control different blades respectively, and when one pitch control system fails, the other pitch control systems can work normally, which is beneficial to improving the safety and reliability of the pitch control system.

In one embodiment, the number of the pitch motors is more than two, the number of the power supply components is one, and the number of the drivers and the backup power supplies is the same as that of the pitch motors; the power supply assembly is connected with each driver, and the backup power supply and the variable pitch motor are respectively and correspondingly connected with the drivers.

Specifically, the number of the pitch motors can be any number of more than two, and the pitch motors are arranged according to actual needs. Referring to fig. 3, a block diagram of another three-blade pitch control system is provided, where the three-blade pitch control system includes three pitch control motors, and the three pitch control motors respectively control corresponding blades and execute pitch control actions. Specifically, the three-blade pitch control system comprises a power supply module, a power supply assembly, three drivers and three backup power supplies. The alternating current output by the power supply module 100 is rectified by the power supply module 200 and then divided into three paths, which are respectively connected with the first driver 301, the second driver 302 and the third driver 303, and the power supply module 200 is further connected with the first backup power source 401, the second backup power source 402 and the third backup power source 403. The first driver 301 is connected with a first variable pitch motor 501; second driver 302 is connected to second pitch motor 502; the third driver 303 is connected to a third pitch motor 503.

When the system is powered on, alternating current output by the power supply module 100 is rectified by the power supply module 200 and then respectively supplies power to different backup power supplies. When the pitch control action is executed, according to the difference of the load borne by the corresponding pitch control motors, the backup power supply and the driver corresponding to each pitch control motor operate in different working modes, and the specific working mode is defined by the reference above and is not repeated herein. When the variable pitch motor is in a power generation state, the fed-back alternating current is converted into direct current through the corresponding driver, and then reaches the corresponding backup power supply to charge the corresponding backup power supply.

In the embodiment, the power supply assemblies of the variable pitch systems corresponding to different blades are integrated, so that the size of the variable pitch system is reduced by the colleague which can ensure the reliability of the variable pitch system.

It is understood that the rectifying unit, the energy storage assembly, the inverter assembly, and the like may take other forms, and are not limited to the forms mentioned in the above embodiments, as long as the corresponding functions can be achieved.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A variable pitch system is characterized by comprising a power supply module, a power supply assembly, a driver, a backup power supply and a variable pitch motor;

the alternating current input end of the power supply assembly is connected with the alternating current power supply end of the power supply module, and the direct current output end of the power supply assembly is connected with the backup power supply and the driver; the driver is connected with the variable pitch motor;

the power supply assembly is used for rectifying alternating current output by the power supply module to obtain direct current to charge the backup power supply and supplying power to the variable pitch motor through the driver; the backup power supply is used for supplying power to the variable pitch motor through the driver when the required variable pitch power of the variable pitch motor is larger than a preset power threshold.

2. The pitch system of claim 1 wherein said drive is a bidirectional AC/DC conversion circuit.

3. The pitch system of claim 1, wherein the power supply assembly comprises a rectification unit and an energy storage unit; the input end of the rectifying unit is connected with the alternating current power supply end of the power supply module; the output end of the rectifying unit is connected with the energy storage unit, the driver and the backup power supply.

4. The pitch system of claim 3 wherein said power supply assembly further comprises a current and voltage limiting unit, said rectifier unit connecting said backup power source and said drive through said current and voltage limiting unit.

5. The pitch system of claim 1 wherein said drive comprises an energy storage assembly and an inverter assembly; one end of the energy storage assembly is connected with the direct current output end of the power supply assembly; the other end of the energy storage assembly is connected with the direct current end of the inversion assembly, and the alternating current end of the inversion assembly is connected with the variable pitch motor.

6. The pitch system of claim 5, wherein the DC output of the power supply assembly is connected to the backup power supply via an energy storage unit of the drive.

7. The pitch system of claim 1 wherein said backup power source is a super capacitor.

8. The variable pitch system according to claim 1, further comprising a bidirectional charger, wherein one end of the bidirectional charger is connected with the driver, and the other end of the bidirectional charger is connected with the backup power supply.

9. The pitch system according to any one of claims 1 to 8, wherein the number of the pitch motors is two or more, and the number of the power supply assembly, the driver and the backup power supply is the same as the number of the pitch motors; the power supply assembly, the backup power supply and the variable pitch motor are respectively and correspondingly connected with the driver.

10. The pitch system according to any one of claims 1 to 8, wherein the number of the pitch motors is two or more, the number of the power supply assemblies is one, and the number of the drivers and the backup power supplies is the same as the number of the pitch motors; the power supply assembly is connected with each driver, and the backup power supply and the variable pitch motor are respectively and correspondingly connected with the drivers.

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