The three-phase asynchronous motor is a widely used type of electric motor, known for its reliability and efficiency. It can be classified based on various factors such as rotor structure, protection type, cooling method, installation style, insulation grade, and working conditions. 1. **Classification by Rotor Structure** - **Squirrel Cage Motor**: The most common type, with a simple and robust design. The rotor consists of aluminum or copper bars connected by end rings, resembling a squirrel cage. - **Wound Rotor Motor**: More complex, with windings on the rotor that can be connected to external resistors for better control of starting and speed. 2. **Classification by Protection Type** - **Open Type (IP11)**: Suitable for clean, dry environments only. - **Protective Type (IP22/IP23)**: Offers some protection against dust and water droplets. - **Closed Type (IP44)**: Ideal for damp or dusty environments. - **Explosion-Proof**: Designed for hazardous areas where flammable gases may be present. 3. **Classification by Cooling Method** - **Self-cooled**: Uses natural convection for heat dissipation. - **Fan-cooled**: Equipped with a fan for enhanced cooling. - **Pipeline Ventilated**: Uses external air flow for cooling, often used in industrial settings. 4. **Classification by Installation Style** - **Horizontal or Vertical**: Depending on how it is mounted. - **Foot-mounted or Flange-mounted**: Based on the mounting method. 5. **Classification by Insulation Grade** - E, B, F, H classes indicate the temperature resistance of the motor's insulation system. 6. **Classification by Duty Cycle** - Continuous, intermittent, or short-time operation based on usage patterns. **Structure of a Three-Phase Asynchronous Motor** **(a) Stator (Stationary Part)** - **Stator Core**: Made of laminated silicon steel sheets, designed to reduce eddy current losses. Slots are cut into the core to house the stator windings. - **Semi-closed Slot**: Used in small motors, offers good efficiency but harder to insulate. - **Semi-open Slot**: Common in medium-sized motors, allows for molded windings. - **Open Slot**: Used in high-voltage motors, easier to insulate. - **Stator Winding**: Consists of three identical windings spaced 120° apart. These windings generate a rotating magnetic field when connected to AC power. - **Base**: Supports the stator and provides structural integrity. Often made of cast iron or steel, with ventilation holes for cooling. **(b) Rotor (Rotating Part)** - **Rotor Core**: Similar to the stator core, made of silicon steel laminations. Slots are punched for the rotor windings. - **Rotor Winding**: - **Squirrel Cage Rotor**: Simple and durable, commonly used in most applications. - **Wound Rotor**: Allows for variable speed control via external resistors. **(c) Other Components** - **End Caps**: Support the rotor and provide structural stability. - **Bearings**: Allow the rotor to rotate smoothly. - **Bearing End Covers**: Protect the bearings from dust and moisture. - **Fan**: Helps cool the motor during operation. **Motor Nameplate Information** - **Model**: Indicates the motor’s size, frame, and pole count (e.g., Y-112M-4). - **Rated Power (PN)**: The mechanical power output at rated conditions. - **Rated Voltage (UN1)**: The voltage applied to the stator windings. - **Rated Current (IN1)**: The current drawn under normal load. - **Rated Speed (nN)**: The speed of the rotor at rated load. - **Rated Frequency (fN)**: Typically 50 Hz or 60 Hz. - **Power Factor (cosφN)**: Measures the efficiency of power usage. - **Connection Method**: Star or Delta connection for the stator windings. - **Protection Class**: Indicates the level of protection against environmental elements (e.g., IP44). Understanding these components and classifications helps in selecting the right motor for specific applications, ensuring optimal performance and longevity.
Oil-immersed Distribution Transformer, its HV level is 15kV, LV is 400V, its capacity is 2500kVA and below. Generally installed on the pole or in the distribution room, for lighting or power supply, three-phase power supply, fully sealed tank structure, to ensure the transformer safe and reliable operation.
Generator Transformer,15Kv Distribution Transformer,15Kv Oil Immersed Transformer,High Quality 1000Kva Transformer
Hangzhou Qiantang River Electric Group Co., Ltd.(QRE) , https://www.qretransformer.com