Variable pitch system back-up power supply charging and discharging circuit

Abstract

The utility model relates to a variable pitch system back-up power supply charge and discharge circuit, charge and discharge are controlled by a variable pitch system back-up power supply charge and discharge control loop, a variable pitch system matched with the variable pitch system back-up power supply charge and discharge circuit is provided with a variable pitch driver and a back-up power supply electrically connected with the variable pitch driver, and the variable pitch driver is provided with a direct current bus. The variable pitch system back-up power supply charging and discharging circuit is arranged between the direct current bus and the back-up power supply; the variable pitch system backup power supply charging and discharging circuit further comprises a charging and discharging loop arranged between the positive electrode of the direct current bus and the positive electrode of the backup power supply and a charging and discharging switch for controlling the charging and discharging loop to be connected or disconnected. The charging and discharging loop further comprises a charging loop and a discharging loop connected in parallel to the charging loop; the charging loop at least further comprises a solid-state relay and a charging diode which are connected in sequence.

Description

Technical Field

[0001] The utility model relates to the technical field of wind turbine generator set backup power supply charging, in particular to a variable pitch system backup power supply charging and discharging circuit. Background Art

[0002] The pitch system is a control device installed in the hub of a wind turbine to adjust the pitch angle of the blades. It is one of the core systems in the control system of a wind turbine. The failure of the pitch system usually causes the wind turbine to be damaged, or even collapse in severe cases, causing huge economic losses and adverse social impacts. The performance of the pitch system plays a vital role in the safety, stability and power generation performance of wind turbines. With the continuous breakthroughs in wind power generation technology, the scale of wind turbines has gradually expanded, and the requirements for pitch systems in wind power generation have become increasingly higher. A safe, reliable and economical pitch system is one of the difficulties in the current technical research of large wind turbines. Due to its importance, the pitch system usually uses two power supply systems: in normal state, the power grid provides power; in abnormal state, such as power outage of the power grid, high / low voltage ride-through timeout of the power grid, the pitch backup power supply system will provide power to the pitch system to complete emergency pitching. The traditional method of charging the backup power supply of the pitch system is to use a dedicated charger to charge the backup power supply. The disadvantage of this method is that the charger is very expensive and often easily damaged.

[0003] Based on the above purpose, the utility model proposes a backup power supply charging and discharging circuit for a pitch control system. Utility Model Content

[0004] The purpose of the utility model is to provide a backup power supply charging and discharging circuit for a variable pitch system in view of the defects existing in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, one of the utility models is a pitch system backup power supply charging and discharging circuit, which is controlled by a pitch system backup power supply charging and discharging control circuit. The pitch system matched with the pitch system backup power supply charging and discharging circuit has a pitch drive and a backup power supply electrically connected to the pitch drive. The pitch drive has a DC bus, and the pitch system backup power supply charging and discharging circuit is arranged between the DC bus and the backup power supply; and the pitch system backup power supply charging and discharging circuit further includes a charging and discharging circuit arranged between the positive pole of the DC bus and the positive pole of the backup power supply and a charging and discharging switch that controls the charging and discharging circuit to be turned on or off, and the charging and discharging circuit is A step includes a charging circuit and a discharging circuit connected in parallel with the charging circuit; the charging circuit at least further includes a solid-state relay and a charging diode connected in sequence, and the solid-state relay is electrically connected to the positive pole of the DC bus, and the negative pole of the charging diode is electrically connected to the positive pole of the backup power supply; the discharging circuit is a discharging diode connected between the positive pole of the backup power supply and the positive pole of the DC bus, and the positive pole of the discharging diode is electrically connected to the positive pole of the backup power supply, and the negative pole of the discharging diode is electrically connected to the positive pole of the DC bus; the negative pole of the backup power supply is electrically connected to the negative pole of the DC bus.

[0006] The charge and discharge switch is a controllable discharge switch arranged in the discharge circuit.

[0007] The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the DC bus, and the cathodes of the solid-state relay and the discharge diode are electrically connected to the DC bus through the controllable charge and discharge switch.

[0008] The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the backup power supply. The cathode of the charging diode and the anode of the discharging diode are electrically connected to the anode of the backup power supply through the controllable charge and discharge switch.

[0009] The charging circuit further includes a current limiting resistor and a fuse which are sequentially arranged between the solid-state relay and the DC bus.

[0010] The charge and discharge switch is a contactor.

[0011] The on-off of the contactor is triggered by a first intermediate relay arranged in the backup power supply charge and discharge control circuit; the on-off of the solid-state relay is triggered by a second intermediate relay arranged in the backup power supply charge and discharge control circuit.

[0012] To sum up, the utility model provides a charging and discharging circuit for a backup power supply of a variable pitch system, which overcomes the problem of high cost and frequent damage of a dedicated charger solution, and has the characteristics of a simple circuit structure. It can ensure that the backup power supply of the variable pitch system is urgently discharged to the variable pitch drive and variable pitch motor in an emergency and complete emergency propeller alignment and normal charging under normal conditions, and other functions corresponding to the dedicated charger. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The present invention is a schematic diagram of an embodiment of a backup power supply charging and discharging circuit of a pitch control system according to the present invention.

[0014] Figure 2 This is a schematic diagram of another embodiment of a backup power supply charging and discharging circuit of a pitch control system according to the utility model.

[0015] Figure 3 The present invention is a schematic diagram of another embodiment of a backup power supply charging and discharging circuit of a pitch control system. DETAILED DESCRIPTION

[0016] In order to explain the technical content, structural features, objectives and effects of the present invention in detail, embodiments are given below with reference to the accompanying drawings for detailed description.

[0017] Unless otherwise stated, all technical and scientific terms used in the embodiments of the present application have the same meaning as those generally understood by those skilled in the art of the present application. The terms used in this application are only for the purpose of describing specific embodiments and are not intended to limit the scope of this application. The term "and / or" used in this application includes any and all combinations of one or more related listed items.

[0018] See also Figures 1 to 3, one of the utility models is a pitch system backup power supply charging and discharging circuit, which is controlled by a pitch system backup power supply charging and discharging control circuit. The pitch system matched with the pitch system backup power supply charging and discharging circuit has a pitch drive and a backup power supply electrically connected to the pitch drive. The pitch drive has a DC bus. The pitch system backup power supply charging and discharging circuit is arranged between the DC bus and the backup power supply; and the pitch system backup power supply charging and discharging circuit further includes a charging and discharging circuit arranged between the positive pole of the DC bus and the positive pole of the backup power supply and a charging and discharging switch that controls the charging and discharging circuit to be turned on or off. The charging and discharging circuit further includes The invention comprises a charging circuit and a discharging circuit connected in parallel with the charging circuit; the charging circuit at least further comprises a solid-state relay and a charging diode connected in sequence, and the solid-state relay is electrically connected to the positive electrode of the DC bus, and the negative electrode of the charging diode is electrically connected to the positive electrode of the backup power supply; the discharging circuit is a discharging diode connected between the positive electrode of the backup power supply and the positive electrode of the DC bus, and the positive electrode of the discharging diode is electrically connected to the positive electrode of the backup power supply, and the negative electrode of the discharging diode is electrically connected to the positive electrode of the DC bus; the negative electrode of the backup power supply is electrically connected to the negative electrode of the DC bus.

[0019] The charge and discharge switch is a controllable discharge switch arranged in the discharge circuit.

[0020] The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the DC bus, and the cathodes of the solid-state relay and the discharge diode are electrically connected to the DC bus through the controllable charge and discharge switch.

[0021] The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the backup power supply. The cathode of the charging diode and the anode of the discharging diode are electrically connected to the anode of the backup power supply through the controllable charge and discharge switch.

[0022] The charging circuit further includes a current limiting resistor and a fuse which are sequentially arranged between the solid-state relay and the DC bus.

[0023] The charge and discharge switch is a contactor.

[0024] The on-off of the contactor is triggered by a first intermediate relay arranged in the backup power supply charge and discharge control circuit; the on-off of the solid-state relay is triggered by a second intermediate relay arranged in the backup power supply charge and discharge control circuit.

[0025] The utility model also discloses a method for charging and discharging a backup power supply of a variable pitch system. The method for charging and discharging a backup power supply of a variable pitch system adopts a charging and discharging circuit of a backup power supply of a variable pitch system as described in one of the utility models. The method for charging and discharging a backup power supply of a variable pitch system comprises:

[0026] According to a charging trigger event or a discharging trigger event, respectively controlling the corresponding charging circuit or the corresponding discharging circuit to enter a backup power supply charging control mode or a backup power supply discharging control mode;

[0027] The charging trigger event is a charging control instruction generated when the real-time acquired backup power supply voltage value is less than a preset backup power supply voltage threshold; the discharging trigger event is a discharging control instruction issued by the main control system or pitch control system of the wind turbine generator set, and the discharging control instruction is triggered by the power failure of the DC bus;

[0028] In the backup power supply charging control mode, the charging circuit is controlled to switch from a disconnected state to a conductive state, and based on the relationship between the voltage value of the backup power supply collected in real time and the voltage threshold of the preset backup power supply, the charging circuit is maintained in the conductive state or is cut off.

[0029] In the backup power supply discharge control mode, the main control system or the pitch control system responds to the discharge trigger event and generates a discharge control instruction to control the discharge circuit to be in a conducting state.

[0030] In the backup power supply charging control mode, the main control system or the variable pitch system controls the controllable charge and discharge switch connected between the charge and discharge circuit and the DC bus or between the charge and discharge circuit and the backup power supply to be turned on, and controls the solid-state relay to be closed through the second intermediate relay, thereby controlling the charging circuit to switch to the on state.

[0031] In the backup power supply discharge control mode, the main control system or the pitch system controls the controllable discharge switch in the charge and discharge circuit, the controllable charge and discharge switch connected between the charge and discharge circuit and the DC bus, or the controllable charge and discharge switch between the charge and discharge circuit and the backup power supply to be closed, thereby controlling the backup power supply to supply power to the pitch drive through the discharge circuit.

[0032] The utility model also discloses a variable pitch system backup power supply charging and discharging device. The variable pitch system backup power supply charging and discharging device is like the variable pitch system backup power supply charging and discharging circuit, and the backup power supply is charged and discharged by the variable pitch system backup power supply charging and discharging method.

[0033] The utility model also discloses a variable pitch system, which adopts the variable pitch system backup power supply charging and discharging device as described above.

[0034] To sum up, the utility model provides a charging and discharging circuit for a backup power supply of a variable pitch system, which overcomes the problems of high cost and frequent damage of a dedicated charger solution, has a simple circuit structure, a convenient and easy control method, etc., and can ensure that the backup power supply of the variable pitch system is urgently discharged to the variable pitch drive and variable pitch motor in an emergency and complete emergency propeller alignment and normal charging under normal conditions, etc., which are functions corresponding to a dedicated charger.

[0035] As described above, it is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A pitch system backup power supply charging and discharging circuit, wherein charging and discharging is controlled by a pitch system backup power supply charging and discharging control circuit, and a pitch system matching the pitch system backup power supply charging and discharging circuit comprises a pitch drive and a backup power supply electrically connected to the pitch drive, wherein the pitch drive has a DC bus, and is characterized in that: The variable pitch system backup power supply charging and discharging circuit is arranged between the DC bus and the backup power supply; and the variable pitch system backup power supply charging and discharging circuit further includes a charging and discharging circuit arranged between the positive pole of the DC bus and the positive pole of the backup power supply and a charging and discharging switch for controlling the charging and discharging circuit to be turned on or off, and the charging and discharging circuit further includes a charging circuit and a discharging circuit connected in parallel to the charging circuit; the charging circuit at least further includes a solid-state relay and a charging diode connected in sequence, and the solid-state relay is electrically connected to the positive pole of the DC bus, and the negative pole of the charging diode is electrically connected to the positive pole of the backup power supply; the discharging circuit is a discharging diode connected between the positive pole of the backup power supply and the positive pole of the DC bus, and the positive pole of the discharging diode is electrically connected to the positive pole of the backup power supply, and the negative pole of the discharging diode is electrically connected to the positive pole of the DC bus; the negative pole of the backup power supply is electrically connected to the negative pole of the DC bus.

2. A pitch system backup power supply charging and discharging circuit according to claim 1, characterized in that: The charge and discharge switch is a controllable discharge switch arranged in the discharge circuit.

3. The backup power supply charging and discharging circuit of a pitch control system according to claim 1, characterized in that: The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the DC bus, and the cathodes of the solid-state relay and the discharge diode are electrically connected to the DC bus through the controllable charge and discharge switch.

4. The backup power supply charging and discharging circuit of a pitch control system according to claim 1, characterized in that: The charge and discharge switch is a controllable charge and discharge switch arranged between the charge and discharge circuit and the backup power supply. The cathode of the charging diode and the anode of the discharging diode are electrically connected to the anode of the backup power supply through the controllable charge and discharge switch.

5. A pitch system backup power supply charging and discharging circuit according to any one of claims 1 to 4, characterized in that: The charging circuit further includes a current limiting resistor and a fuse which are sequentially arranged between the solid-state relay and the DC bus.

6. A pitch system backup power supply charging and discharging circuit according to claim 5, characterized in that: The charge and discharge switch is a contactor.

7. A pitch system backup power supply charging and discharging circuit according to claim 6, characterized in that: The on-off of the contactor is triggered by a first intermediate relay arranged in the backup power supply charge and discharge control circuit; the on-off of the solid-state relay is triggered by a second intermediate relay arranged in the backup power supply charge and discharge control circuit.

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