Variable-pitch driver with boosting function

Abstract

The invention discloses a variable-pitch driver with a boosting function. The variable-pitch driver comprises a driver, a direct-current bus, a backup power supply, a charging management unit and an intermediate relay, the driver is connected with the backup power supply through the charging management unit; a booster circuit is arranged in the driver, the direct current bus is connected with the charging management unit through the booster circuit, the direct current bus is connected with the charging management unit through the intermediate relay, and the booster circuit is connected with the intermediate relay in parallel. According to the scheme, manual switching is not needed in the using process through the driver, the intermediate relay and the booster circuit, software controls switching-in and switching-out of the booster circuit through the intermediate relay, the backup power source can be utilized to 50 V, the overall energy efficiency is improved by about 13%, the size and scale of the backup power source are reduced, the replacement pressure of operation and maintenance personnel is relieved, and the maintenance cost is reduced. And on a large megawatt fan, the cost of the super capacitor is obviously reduced.

Description

Technical Field

[0001] The invention relates to the technical field of variable pitch drives, and in particular to a variable pitch drive with a boosting function. Background Art

[0002] A wind turbine pitch control system generally consists of a pitch drive, a motor, and a backup power supply (supercapacitor). The pitch drive drives the motor to change the windward angle of the blades. The backup power supply (supercapacitor) is used to provide energy to drag the blades back to a safe position when the mains power is off or unstable. According to relevant standards of the pitch industry, the energy requirements of the backup power supply must be sufficient to meet at least one full-angle pitch adjustment, that is, to meet the safety requirements for returning the blades from 0° to 90°.

[0003] In the current variable pitch system, when the bus voltage of the driver is lower than 150V, the motor can no longer be driven. When the backup power supply is fully charged, it is generally 400-450V. In order to meet the requirements of full pitch and 10-year service life, the designer needs to design the energy discharged from the capacitor from full charge to 150V to be greater than the energy consumed by pitch, but in fact 150V of energy is wasted. With the increasing trend of wind turbine capacity and the service life of 10 years of capacity reduction, the backup power supply capacity is getting larger and larger. According to E=1 / 2UC2, the energy waste caused is getting more and more serious, and the operation and maintenance work such as replacement and maintenance is becoming more and more difficult. Summary of the invention

[0004] In order to solve the above technical problem, the technical problem to be solved by the present invention is to provide a variable pitch drive with a boost function.

[0005] To achieve the above-mentioned purpose, the present invention provides a variable pitch drive with a boost function, comprising: a drive, a DC bus, a backup power supply, a charging management unit and an intermediate relay; the drive is connected to the backup power supply through the charging management unit; a boost circuit is arranged inside the drive, the DC bus is connected to the charging management unit through the boost circuit, the DC bus is connected to the charging management unit through the intermediate relay, and the boost circuit and the intermediate relay are connected in parallel.

[0006] Furthermore, the charging management unit is provided with a BT+ interface and a BT- interface.

[0007] Further, the BT+ interface is connected to an intermediate relay, the intermediate relay is connected to the positive electrode of a diode D1, the negative electrode of the diode D1 is connected to the positive electrode of the DC bus, and the negative electrode of the DC bus is connected to the BT- interface.

[0008] Furthermore, the boost circuit is a BOOST boost circuit, which includes a MOS tube, a filter capacitor C1, a filter capacitor C2, a diode D2 and an inductor L. The BT+ interface is connected to the intermediate relay, and the intermediate relay is respectively connected to the filter capacitor C1 and the inductor L; the inductor L is respectively connected to the positive electrode of the diode D2 and the drain of the MOS tube, and the negative electrode of the diode D2 is respectively connected to the positive electrode of the DC bus and the filter capacitor C2; the source of the MOS tube, the filter capacitor C1 and the filter capacitor C2 are respectively connected to the BT-interface; the gate of the MOS tube is grounded.

[0009] Compared with the prior art, the present invention produces the following beneficial effects: a variable pitch drive with a boost function according to the present invention uses a drive, an intermediate relay and a boost circuit so that manual switching is not required during use. The software controls the switching in and out of the boost circuit through an intermediate relay, and can utilize the backup power supply to 50V. The overall energy efficiency is improved by about 13%, the size of the backup power supply is reduced, and the replacement pressure on operation and maintenance personnel is reduced. In large-megawatt wind turbines, supercapacitors can significantly reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the circuit principle diagram of the present invention;

[0011] Figure 2 It is a topological structure diagram of the present invention;

[0012] Explanation of reference numerals: 1-MOS tube; 2-intermediate relay. DETAILED DESCRIPTION

[0013] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0014] See also Figure 1-2The preferred embodiment of the present invention provides a variable pitch drive with a boost function, including: a drive, a DC bus, a backup power supply, a charging management unit and an intermediate relay; the drive is connected to the backup power supply through the charging management unit; a boost circuit is provided inside the drive, the DC bus is connected to the charging management unit through the boost circuit, the DC bus is connected to the charging management unit through the intermediate relay, and the boost circuit and the intermediate relay are connected in parallel; the charging management unit is provided with a BT+ interface and a BT- interface; the boost circuit is a BOOST boost circuit. This device provides a variable pitch drive with a boost function to overcome the waste of backup power supply energy, which can drive the motor normally when the backup power supply is lower than 150V, until 50V. This solution uses a driver, an intermediate relay and a boost circuit to eliminate the need for manual switching during use. The software controls the switching in and out of the boost circuit through an intermediate relay, which can utilize the backup power supply up to 50V. The overall energy efficiency is improved by about 13%, which reduces the size of the backup power supply and reduces the replacement pressure on operation and maintenance personnel. Supercapacitors can significantly reduce costs on large-megawatt wind turbines.

[0015] The variable pitch drive is connected to the backup power supply through the BT+ interface and the BT- interface, and the BOOS boost circuit is connected to the DC bus inside the drive, and the switching on and off of the boost circuit is controlled by the intermediate relay. That is, compared with the traditional variable pitch drive, an intermediate relay and a boost circuit are connected in series between the backup power supply and the DC bus, and the two are in a parallel relationship. The interface reserved for customers is consistent with the traditional drive, namely, the BT+ interface and the BT- interface, and the customer does not need to modify the external circuit; in addition, during the use of the present invention, the intermediate relay does not need to be manually switched, and the software automatically controls the intermediate relay to switch the BOOST boost circuit on and off. When and only when the driver detects that the input mains power is disconnected and the bus voltage is lower than 200V, the software output closes the intermediate relay downward and the boost circuit is switched on. According to the detected input voltage (backup power supply voltage), the software adjusts the duty cycle of the diode opening and closing in the BOOST boosting circuit. The BOOST circuit will continuously charge and discharge to make the output voltage greater than the input voltage (backup power supply voltage), and the bus voltage will stabilize at around 200V, efficiently utilizing the backup power supply energy until the backup power supply is exhausted to 50V. When the mains power returns, the bus voltage is detected to be higher than 250V, the software controls the intermediate relay to disconnect, and the boost circuit is switched off.

[0016] Preferably, the BT+ interface is connected to an intermediate relay, the intermediate relay is connected to the anode of a diode D1, the cathode of the diode D1 is connected to the anode of the DC bus, and the cathode of the DC bus is connected to the BT- interface.

[0017] Preferably, the boost circuit includes a MOS tube, a filter capacitor C1, a filter capacitor C2, a diode D2 and an inductor L, the BT+ interface is connected to the intermediate relay, and the intermediate relay is respectively connected to the filter capacitor C1 and the inductor L; the inductor L is respectively connected to the positive electrode of the diode D2 and the drain of the MOS tube, and the negative electrode of the diode D2 is respectively connected to the positive electrode of the DC bus and the filter capacitor C2; the source of the MOS tube, the filter capacitor C1 and the filter capacitor C2 are respectively connected to the BT- interface; the gate of the MOS tube is grounded. When the intermediate relay fails and the boost circuit cannot be disconnected upward, the diode will be cut off to prevent the DC bus from reversely charging the backup power supply, and the software will report a fault, and the fan will return to a safe position.

[0018] From the above description, it can be seen that the above-mentioned embodiments of the present invention achieve the following technical effects: the scheme uses a driver, an intermediate relay and a boost circuit, so that no manual switching is required during use. The software controls the switching in and out of the boost circuit through an intermediate relay, and can utilize the backup power supply to 50V. The overall energy efficiency is improved by about 13%, the size of the backup power supply is reduced, and the replacement pressure on operation and maintenance personnel is reduced. In large-megawatt wind turbines, supercapacitors significantly reduce costs.

[0019] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A variable pitch drive with boost function, characterized in that: include: Driver, DC bus, backup power supply, charge management unit and intermediate relay; The driver is connected to the backup power supply through the charging management unit; a boost circuit is provided inside the driver, the DC bus is connected to the charging management unit through the boost circuit, the DC bus is connected to the charging management unit through the intermediate relay, and the boost circuit and the intermediate relay are connected in parallel.

2. A variable pitch drive with boost function according to claim 1, characterized in that: The charging management unit is provided with a BT+ interface and a BT- interface.

3. A variable pitch drive with boost function according to claim 2, characterized in that: The BT+ interface is connected to an intermediate relay, the intermediate relay is connected to the positive electrode of a diode D1, the negative electrode of the diode D1 is connected to the positive electrode of the DC bus, and the negative electrode of the DC bus is connected to the BT- interface.

4. The variable pitch drive with boost function according to claim 2, characterized in that: The boost circuit is a BOOST boost circuit, which includes a MOS tube, a filter capacitor C1, a filter capacitor C2, a diode D2 and an inductor L. The BT+ interface is connected to the intermediate relay, and the intermediate relay is respectively connected to the filter capacitor C1 and the inductor L; the inductor L is respectively connected to the positive electrode of the diode D2 and the drain of the MOS tube, and the negative electrode of the diode D2 is respectively connected to the positive electrode of the DC bus and the filter capacitor C2; the source of the MOS tube, the filter capacitor C1 and the filter capacitor C2 are respectively connected to the BT-interface; the gate of the MOS tube is grounded.

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