Abstract: This article mainly introduces the application technology of frequency converters in the main drive system of winches. Practice shows that Delta B-series frequency converters can fully meet customer needs, laying a solid foundation for the hoisting industry market. Keywords: lifting, braking, holding brake 1 Introduction A winch, also known as a hoisting machine, is a lifting device that uses a power-driven drum to lift and move heavy objects through flexible parts (wire rope, chain). It has a simple structure, is easy to use, and is widely used in traction and lifting operations in construction, installation, transportation and other departments. Winches can be divided into two main categories according to the drive method: manual drive and electromechanical drive. This article discusses the frequency conversion speed regulation drive technology of electrically driven winches. Electric winches can be divided into fast and slow types according to the traction speed. Fast winches generally have a traction speed of 30-50m/min and are mostly used on construction sites. Slow winches have a traction speed of 7-15m/min and are mainly used for equipment installation operations. 2 Overview of Electric Winches The winch consists of a main unit such as a motor, reducer, drum, and wire rope mounted on a chassis base, as well as auxiliary components such as an electro-hydraulic actuator, clutch, rope guide for orderly winding of the wire rope, stopper to prevent the drum from reversing, electromagnetic brake for deceleration and stopping, and electrical control box. The appearance of the winch is shown in Figure 1. [align=center] Figure 1 Winch Appearance[/align] 3 Variable Frequency Speed ​​Regulation Design of Winches 3.1 Variable Frequency Speed ​​Regulation of Winches In the traction and lifting operations of construction, installation, transportation and other departments, speed regulation of winches is an important functional design. Compared with the usual fixed speed winches, variable speed winches have a wider range of operational adaptability and better operating efficiency and operational safety and stability. Compared with the past variable speed winches such as wound-rotor asynchronous motors, the technological superiority of today's variable frequency speed regulation is self-evident. 3.2 Variable Frequency Speed ​​Regulation Design Requirements (1) Rated load: 12 tons; Overweight load: 13 tons. (2) The starting torque is large, and the lifting is done when the brake is released. There should be no slippage of the hook. (3) When the load is lowered, the inverter provides sufficient braking torque to overcome the acceleration of the load. (4) During operation, there is a high-low speed switching and two acceleration times. (5) The travel speed of the load is 14 m/min. (6) Due to the presence of the mechanical brake, the output torque of the inverter and the braking torque of the mechanical brake must be switched smoothly to avoid slippage of the hook. 4 Delta B-series inverter application design 4.1 Electromechanical system configuration (1) Delta B-series inverter model: VFD045B43A; braking unit: VFDB4045; braking resistor: 10000W/13.33 ohms. (2) Motor parameters: Model: YZB250M1-6M; Power: 37KW; Rated speed: 982r/min; Voltage: 380V; Current: 72.6A; 5-50HZ constant torque; 50-100 constant power. (3) Cylindrical gear reducer: Model: ZQ650-31.5-4; Transmission ratio: 31.5; Center distance: 650mm. 4.2 Electrical schematic design The electrical schematic design of the winch speed control system based on Delta B-series frequency converter is shown in Figure 2. The system control uses frequency converter terminal control, including forward and reverse control, multi-function selection control (MI terminal), multi-function indication selection contact (signal output), and energy consumption braking is achieved by the braking unit matched with the B-series frequency converter. [align=center] Figure 2 Electrical schematic design[/align] The multi-function relay output RA, RC is connected to the mechanical brake coil to control the opening of the mechanical brake. Most frequency converters are set to indicate operation, but the external load is inconsistent during startup and shutdown, causing hook slippage. Therefore, Delta developed a mechanical brake control for this application, separating the startup and shutdown frequencies, greatly simplifying commissioning time and achieving ideal results. If applied to a high-speed winch, due to the motor's small reduction ratio, the frequency converter must output 180% of its rated torque at the moment of brake release to ensure the load does not slip. Therefore, the values ​​of 01-05 and 01-06 should be adjusted appropriately to allow the frequency converter to withstand current surges. The faster the winch's travel speed and the smaller the motor's reduction ratio, the greater the instantaneous current experienced by the frequency converter. The motor's overload capacity reaches 6 times its rated current, but the frequency converter can only reach 2 times its rated current. Therefore, the frequency converter's power must be increased to avoid overload damage (see Table 1). Table 1 shows the current output values ​​during operation. During the descent, regardless of changes in the load, the current displayed by the frequency converter remains essentially constant (60A), which may result in a consistent braking torque output from the frequency converter. In high-speed winches, increasing the braking torque may require using two 4030 braking units with 10-ohm braking resistors. This reduces the hook travel when the descent stops. 4.3 Debugging Parameters 01-00=50 Maximum Operating Frequency 01-01=50 Motor Rated Frequency Setting 01-02=380 Motor Rated Voltage Setting 01-03=3 Intermediate Frequency Setting 01-04=30 Intermediate Voltage Setting 01-05=0.1 Minimum Output Frequency Setting 01-06=10 Minimum Output Voltage Setting 01-09=10 First Acceleration Time Setting 01-10=10 First Deceleration Time Setting 01-11=5 Second Acceleration Time Setting 02-01=1 External Terminal Operation Keyboard STOP Key Effective 03-00=29 Mechanical Brake Control 03-13=3 Mechanical Brake Release Frequency 03-14=5 Mechanical Brake Action Frequency 04-04=01 Multi-Speed ​​Operation 04-05=07 First and Second Acceleration Time Switching 05-00=50 First Speed ​​Frequency Setting 06-00=0 Overvoltage stall prevention function ineffective 07-04=6 Motor pole number 08-16=1 No automatic voltage regulation function 08-17=740 Soft braking level F=20.00HZ 5. Conclusion: Delta B-series frequency converters feature sensorless vector control technology. With a 0.5Hz output, they provide over 150% high starting torque, ensuring motor torque during suspended starts and low-speed operation. They can operate continuously at 100% torque within a 1:10 speed range (6-60Hz/5-50Hz). Speed ​​regulation deviation is less than ±1%. A high-speed microprocessor and DSP are used to improve response speed, effectively preventing "slippage" in lifting equipment. Torque response time is approximately 0.1 seconds to achieve 100% torque. During descent, the frequency converter experiences a high potential energy release process. To prevent overvoltage tripping and damage, an energy-dissipating braking unit is added to ensure normal operation of the frequency converter. During braking, the discharge resistor combines with the active power loss portion inside the motor to form the braking torque. Reference [1] VFD-B Inverter Manual. Delta Electronics Co., Ltd.