A rapid cable release control method and system for an electric winch

Abstract

The present invention discloses a method and system for quickly paying out cable of an electric winch, belonging to the field of electric winches. When the winch system enters the cable payout mode, the measured bus voltage is compared with the set bus voltage threshold in real time. When the bus voltage value is less than the bus voltage threshold by a Δ, the duty ratio of the braking resistor switch tube is set to 0 at this time, that is, the braking resistor does not work at all. When the bus voltage value is greater than the bus voltage threshold by a Δ, the duty ratio of the braking resistor switch tube is set to 1 at this time, that is, the braking resistor is always in the working mode. When the bus voltage is within the range of the bus voltage threshold ±Δ, the duty ratio of the braking resistor switch tube is given according to a preset rule. Through the control of the braking resistor and the anti-backflow of the diode, the supply voltage of the motor during cable payout of the winch can be stably controlled to a preset interval higher than the voltage at the power supply input end, and a shorter cable payout time than the prior art can be achieved under the same power supply.

Description

Technical Field

[0001] The present invention relates to the field of electric winches, and more specifically, to a method and system for controlling rapid cable payout of an electric winch. Background Art

[0002] Winches are widely used in deep - sea exploration, mine operations, helicopter rescue and other scenarios. Their main function is to achieve cable payout and cable retraction, and they can be composed of a controller, a transmission device, a cable storage reel, a brake, etc.

[0003] With the development of motor control technology, electric winches have received wide attention due to their high control flexibility, low environmental pollution, high work efficiency and other advantages. As the core component of an electric winch, how to give full play to the performance of the motor will directly affect the work efficiency of the entire winch. In some fields, such as aircraft rescue, due to factors such as the voltage of the on - board power supply and the volume of the motor, the motor speed is also limited within a certain range, resulting in the cable payout time not being able to be further accelerated and the performance of the motor not being fully utilized. Therefore, in some application fields that require high - speed winches, a control system and method are needed to accelerate the cable payout time and improve the overall efficiency of the winch. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a control circuit and a control method for rapid cable payout of an electric winch, aiming to significantly increase the motor speed and reduce the cable payout time without increasing the power of the system power supply to meet the need for rapid cable payout in some special application scenarios.

[0005] To achieve the above - mentioned purpose, the present invention provides a method for controlling rapid cable payout of an electric winch. The circuit includes a power module, a DC bus capacitor module, a braking resistor module, and a diode anti - reverse - flow module.

[0006] The power module includes the first to sixth switching tubes, which are connected to the DC bus; the DC bus capacitor module includes a DC bus capacitor, which is connected in parallel to the positive and negative poles of the DC bus; the braking resistor module includes a seventh switching tube and a resistor device, and after the seventh switching tube and the resistor device are connected in series, they are connected in parallel to both ends of the DC bus; the diode anti - reverse - flow module is connected in series to the positive pole of the DC bus, and the diode is at the front end of the DC bus and the anode of the diode is close to the power input terminal.

[0007] The power module is used to drive the motor; the DC bus capacitor module is used for filtering and limited energy storage of the bus; the braking resistor module includes a braking resistor and a braking resistor switching tube, which are connected in series and then incorporated into the DC bus, and are used to consume the energy generated by the motor braking on the bus to stabilize the bus voltage; the diode anti - reverse - flow module is used to prevent the current on the bus from flowing back and affecting the power supply when the bus voltage rises.

[0008] When the winch system enters the cable-laying mode, the cable storage motor immediately enters the speed loop control; the brake of the cable storage motor is opened, and the cable is dragged by the action of gravity to drive the reel to rotate; the cable storage motor is controlled to gradually increase to the set maximum speed according to the motor rotation direction in the cable-laying state. In this working condition, the control method includes the following steps:

[0009] S1. Measure the value of the inverter bus voltage in real time;

[0010] S2. Compare the bus voltage with the set bus voltage value in real time to control the state of the braking resistor switch tube; when the bus voltage value is less than the set bus voltage value by a Δ (this Δ is an adjustable parameter), it means that the bus voltage has not reached the set voltage value range. At this time, the duty ratio of the braking resistor switch tube is given as 0, that is, the braking resistor does not work at all. When the bus voltage value is greater than the set bus voltage value by a Δ, at this time, the duty ratio of the braking resistor switch tube is given as 1, that is, the braking resistor is always in the working mode. When the bus voltage is within the range of the set bus voltage value ±Δ, the duty ratio control of the braking resistor switch tube is given according to a certain rule. The duty ratio control rate of the braking resistor switch tube is:

[0011]

[0012] where x is the measured value of the inverter bus voltage, U is the set bus voltage threshold, and Δ is the duty ratio ramp range.

[0013] The present invention mainly includes two parts of control: speed control in the motor power generation state and bus voltage control of the power module. Among them, the speed control in the motor power generation state can adopt the traditional vector control of the permanent magnet synchronous motor, and the bus voltage control is mainly controlled by controlling the conduction of the braking resistor switch tube.

[0014] Further, the speed control in the motor power generation state is to control the cable-laying of the cable storage reel according to the specified speed, and the speed setting is calculated according to the cable-laying time required by the specific working condition; when the winch is in the cable-laying mode, the torque direction of the motor is opposite to the speed direction, and the motor is in the power generation state. During the cable-laying operation, the energy generated by the motor will be rectified and fed back to the DC bus through the power module, and the DC bus voltage will be lifted;

[0015] Further, as the bus voltage is gradually lifted, a voltage difference will be formed across the diode anti-backflow module, and the bus voltage on the power module side will be higher than the power supply voltage; due to the function of the diode anti-backflow module, the higher voltage on the power module side will not affect the voltage on the power supply side.

[0016] The control of the cable storage motor and the control of the inverter bus voltage belong to coordinated control. The control objective of the inverter bus voltage control is to control the inverter bus voltage at the voltage corresponding to the highest speed at which the cable storage motor can operate, and a certain voltage margin can be reserved according to the actual situation.

[0017] According to this control method, when the winch system enters the cable-laying mode, the cable storage motor is in the generator state. The bus voltage can be maintained at a certain operating point above the rated working voltage by controlling the braking resistor. At this time, the DC bus voltage is no longer limited by the power supply voltage. Since the motor speed is basically proportional to the voltage under the same conditions, the motor speed can also be increased synchronously.

[0018] On the other hand, the present invention provides a fast cable-laying control system for an electric winch, including: a computer-readable storage medium and a processor;

[0019] The computer-readable storage medium is used to store executable instructions;

[0020] The processor is used to read the executable instructions stored in the computer-readable storage medium and execute the above-mentioned fast cable-laying control method for the electric winch.

[0021] Through the above technical solutions conceived by the present invention, compared with the prior art, through the control of the braking resistor and the function of the diode anti-backflow module, the power supply voltage of the motor during cable-laying of the winch can be stably controlled to a preset interval higher than the voltage at the power supply input end, and a shorter cable-laying time than the prior art can be achieved under the same power supply. Description of the Drawings

[0022] Figure 1 It is a main circuit schematic diagram of the present invention;

[0023] Figure 2 It is a flowchart of the fast cable-laying control method for the electric winch provided by the present invention;

[0024] Figure 3 It is a curve of the duty cycle of the braking resistor unit changing with the inverter bus voltage of the present invention. Detailed Embodiments

[0025] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit 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.

[0026] As Figure 1 shown is a main circuit schematic diagram of a winch, Q1 -Q 6 Six switching tubes form the cable storage motor control power module, Q 7 is the braking resistor switch tube, R 1 is the braking resistor, C 1 is the DC bus support capacitor, D 1 is the DC bus anti-backflow diode, Motor is a permanent magnet synchronous motor, including a motor brake, used to drive the cable storage reel and stop braking, u dc1 is the voltage on the DC power supply side, u dc2 is the inverter bus voltage after passing through the anti-backflow diode D 1 as shown below.

[0027] As Figure 2 shown, the control method of the present invention is executed according to the following steps:

[0028] S1. The winch system enters the cable-laying mode, and the cable storage motor Motor immediately enters the speed loop control.

[0029] S2. The cable storage motor brake is opened, and the cable drags the reel to rotate under the action of gravity.

[0030] S3. The controller controls the cable storage motor to gradually increase to the set maximum speed according to the motor rotation direction in the cable-laying state.

[0031] S4. The value of the inverter bus voltage u dc2 measured in real time.

[0032] S5. The value of the bus voltage u dc2 is compared with the set bus voltage value U in real time to control the braking resistor; when u dc2 is less than U - Δ, it means that the bus voltage has not reached the set voltage value range. At this time, the duty ratio of the braking resistor switch tube Q 7 is given as 0, that is, the braking resistor does not work at all. When u dc2 is greater than U + Δ, it means that the bus voltage has exceeded the set voltage value by a large margin. At this time, the duty ratio of the braking resistor switch tube Q 7 is given as 1, that is, the braking resistor is always in the working mode. When u dc2 is between U - Δ and U + Δ, it means that the bus voltage is near the set voltage at this time, and the duty ratio of the braking resistor switch tube is given according to a certain rule.

[0033] Furthermore, the bus voltage set value is obtained according to the actual motor control requirements, and this set value should be greater than the DC power supply voltage u dc1 , and satisfy that the motor can operate at the highest allowable speed.

[0034] Furthermore, the braking resistor switch tube is according to Figure 3It is controlled by the duty ratio setting method. Specifically, the control rate of the braking resistor switch tube is as follows:

[0035]

[0036] Among them, x is the value of the inverter bus voltage measured by the system, U is the above-mentioned bus voltage setting threshold, which needs to be obtained according to the speed-voltage relationship of the actual motor, Δ is the duty ratio ramp range, and needs to be set according to the specific working conditions.

[0037] Furthermore, due to the existence of the DC bus anti-backflow diode D 1 When u dc2 is greater than u dc1 After that, the cathode voltage of the diode is higher than the anode voltage, and the diode is in the reverse cut-off state, and the bus current will not flow back, so the higher voltage of u dc2 will not affect the u dc1 side.

[0038] According to this control method, when the winch system enters the cable-laying mode, the cable storage motor is in the generator state, and the bus voltage can be maintained at a certain working point above the rated working voltage by controlling the braking resistor. At this time, the DC bus voltage is no longer limited by the power supply voltage. Since the motor speed and voltage are basically proportional under the same conditions, the motor speed can also be increased synchronously.

[0039] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control method for rapid cable release of an electric winch, characterized in that, when the winch system enters the cable release mode, it includes the following steps: S1. Measure the value of the inverter bus voltage in real time; S2. Compare the bus voltage with the set bus voltage threshold value in real time to control the state of the braking resistor switch tube; when the bus voltage value is less than the bus voltage threshold value by a Δ, at this time the duty ratio of the braking resistor switch tube is set to 0, that is, the braking resistor does not work at all, when the bus voltage value is greater than the bus voltage threshold value by a Δ, at this time the duty ratio of the braking resistor switch tube is set to 1, that is, the braking resistor is always in the working mode, when the bus voltage is within the range of the bus voltage threshold value ±Δ, the duty ratio control of the braking resistor switch tube is given according to a preset rule; The duty ratio control rate of the braking resistor switch tube is: where x is the measured value of the inverter bus voltage, U is the set bus voltage threshold value, and Δ is the duty ratio ramp range.

2. The control method according to claim 1, characterized in that, when the winch system is in the cable release mode, the cable storage motor enters the speed loop control.

3. The control method according to claim 2, characterized in that, the speed loop control in the power generation state of the cable storage motor is the vector control of a permanent magnet synchronous motor.

4. The control method according to claim 2, characterized in that, the cable storage motor gradually increases to the set maximum speed according to the motor rotation direction in the cable release state.

5. An electric winch rapid cable release control system, characterized in that, it includes: a computer-readable storage medium and a processor; the computer-readable storage medium is used to store executable instructions; the processor is used to read the executable instructions stored in the computer-readable storage medium and execute the electric winch rapid cable release control method according to any one of claims 1 to 4.

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