Customized High Power Low Speed Permanent Magnet Synchronous Motor

There are many ways to start a permanent magnet synchronous motor, including direct start, self-coupling decompression start, Y-Δ decompression start, soft start, inverter start, etc. So what's the difference between them?

1. When the grid capacity and load allow full voltage direct start, full voltage direct start can be considered. The advantages are convenient operation and control, simple maintenance, and high economy. It is mainly used to start small power motors.

2. The automatic transmission starts using the multi-touch of the automatic transmission to reduce the pressure, which can not only meet the needs of different loads but also the starting torque will be larger. It is a decompression starting method and is often used to start high-capacity motors.

3. Y-Δ starts to run normally. The squirrel cage asynchronous motor is wound and connected to the delta stator. If the stator is wound into a star when starting, and then connected to the delta after starting, the starting current can be reduced and the impact on the power grid can be alleviated. This start-up mode is referred to as a star-delta decompression start, or star-delta start (Y-delta start). It is suitable for no-load or light-load starting. Compared to any other decompression starter, it has the simplest structure and is also less expensive. In addition, the star-delta starting mode has another advantage, that is, the permanent magnet synchronous motor can be operated in star-connected mode when the load is light. At this time, the rated torque and load can be matched, thereby improving the efficiency of the motor and saving power consumption.

4. The soft starter adopts the phase-shift voltage regulation principle of the silicon-controlled rectifier to realize the voltage regulation start of the motor. It is mainly used for starting control of permanent magnet synchronous motors, with a good starting effect and high cost.

5. The frequency converter is a motor control device with the highest technical content, the most complete control functions, and the best control effect in the field of modern motor control. It adjusts the speed and torque of the permanent magnet synchronous motor by changing the frequency of the power grid, and it is mainly used in fields that require high requirements for speed regulation and high-speed control.

Decompression start, a common star-delta start, the disadvantage is that the starting torque is small, only suitable for a no-load or light-load start. The advantage is that it is cheap. Soft start, you can set the start time and the initial torque of the starting equipment, realize a soft start and soft stop, and limit the starting current, the price is moderate. Frequency conversion start, starts smoothly according to the set time and lets the equipment run at the set frequency, the price is high.

The characteristics and advantages of permanent magnet motors

Motor From the source of excitation can be divided into two categories: permanent magnet motor, and electric excitation motor. A permanent magnet motor is an electric motor that produces an excitation magnetic field from a permanent magnet. The most widely used three-phase asynchronous motors in industry and civil use, such as Y-Series, Y2-Series, YE2-Series, YX3 Series, Series YB, series YB2 series, etc. all belong to electric excitation motors. ENNENG Motor products are ultra-efficient permanent magnet synchronous motors.

Compared with traditional electric excitation motors, permanent magnet motors, especially rare earth permanent magnet motors, have the advantages of simple structure, reliable operation, small size, lightweight, small loss and high efficiency, and flexible and diverse shape and size of the motor. The application is extremely wide, covering almost all areas of aerospace, national defense, industrial and agricultural production, and daily life.

The permanent magnet synchronous motor has the following characteristics:

• Rated efficiency is 2% to 5% higher than normal asynchronous motors;
• The efficiency rises rapidly with the increase of the load. When the load changes within the range of 25% to 120%, it maintains high efficiency. The high-efficiency operating range is much higher than that of ordinary asynchronous motors. Light-load, variable-load, and full-load all have significant energy-saving effects;
• Power factors up to 0.95 and above, no reactive compensation required;
• The power factor is greatly improved. Compared with asynchronous motors, the running current is reduced by more than 10%. Due to the decrease in operating current and system losses, energy-saving effects of about 1% can be achieved.
• Low-temperature rise, high power density: 20K lower than three-phase asynchronous motor temperature rise, design temperature rise is the same and can be made into a smaller volume, saving more effective materials;
• High starting torque and high overload capacity: according to requirements, it can be designed with high starting torque (3-5 times) and high overload capacity;
• The variable frequency speed control system is used, which is better in dynamic response and better than that of asynchronous motors.
• The installation dimensions are the same as the asynchronous motors currently widely used, and the design and selection are very convenient.
• Due to the increase in power factor, the visual power of the power supply system transformer is greatly reduced, which improves the power supply capacity of the transformer, and can also greatly reduce the cost of the system cable (new project);
• When the new project is built, all the drive systems use permanent magnet synchronous motors, the project investment is basically the same as the use of asynchronous motors, and the project can continue to obtain energy-saving benefits after the project is put into operation;

In the general industrial sector, the replacement of low-voltage(380/660/1140V) high-efficiency asynchronous motors, system saves 5% to 30% energy, and the high-voltage(6kV/10kV) high-efficiency asynchronous motors, the system saves 2% to 10%.

Attention:

1. TYP series high-efficiency permanent magnet variable frequency synchronous motor must be used together with the permanent magnet motor frequency converter. It is forbidden to connect to the three-phase current directly without the converter;

2. TYP series high-efficiency permanent magnet variable frequency synchronous motor frequency converter must adopt the maximum torque/current ratio control mode, otherwise, it cannot reach the optimal working state, which will cause the decline of the motor power factor and torque reduction;

3. TYP series high-efficiency permanent magnet variable frequency synchronous motor adopts Y connection, and Y/△ connection is not allowed.