Vector Frequency Converter

A: Yes, Sample order is available for quality check and market test .But you have to pay for it .

A: It usually takes about 3-5 working days for small order and 10-15 days for big order .

A: We usually accept all kinds of payment terms .Such as T/T,L/C, Western Union.Cash.

A: We offer 24 months warranty time .

A: Depends on your request ,We have standard models in stock. Some special products and big order will be newly produced according to your order .

A: Yes ,Different models can be mixed up in one container ,even one order .

A: Quality is priority ,we always attach the importance to quality control from the beginning to the end of the production .every product will be fully assembled and carefully tested before packing and shipping .

A: If you are using our products .we can sell spare parts to you . But we couldn't sell the half-finished products.

A: Yes .We have the right to export and can sell electrical product all over the world..

A: Yes. We have a lot of experience to design frequency inverter and soft starter cabinet according to your request,and our factory can do soft starter by ourselves.

A: Yes .All inverters have built-in RS485 port .and support Modbus communication protocol.

A: Our company has been audited and approved ISO9001,CE.CCC. Assessment report will could be sent to you by e-mail. and we will take all the responsibility once problem during warranty time.

A: A vector-controlled frequency inverter does not control an AC motor using a voltage/frequency ratio, but by varying the motor input frequency and voltage. An advantage of this method is optimum torque control. Vector-controlled frequency inverters offer other advantages too.

A: Inverters can be roughly divided into two categories: high-voltage frequency converters and low-voltage converters. In terms of use, the applicable objects are different; in terms of speed regulation principle, both are the same; in terms of topology, the difference between the two is It is very large, mainly due to the insufficient withstand voltage of the currently widely used IGBT modules. Due to the high voltage of the high-voltage frequency converter, the interference to the driving circuit is also large, and the optical fiber is usually used for isolation.

A: The torque of the asynchronous motor is generated by the interaction between the magnetic flux of the motor and the current flowing in the rotor. At the rated frequency, if the voltage is constant and only the frequency is reduced, the magnetic flux is too large, the magnetic circuit is saturated, and the motor The current increases, and the motor will be burned in severe cases. Therefore, the frequency and voltage should be changed proportionally, that is, the output voltage of the inverter should be controlled while the frequency is being changed, so that the magnetic flux of the motor is kept constant and the occurrence of magnetic saturation is avoided. The voltage here refers to the rms value of the line voltage or phase voltage of the motor.

A: The inverter is used for operation, and the frequency and voltage are correspondingly increased with the acceleration of the motor, and the starting current is limited to below 150% of the rated current (125% to 200% depending on the model). When using the power frequency power supply to start directly, the starting current is 6 to 7 times, so there will be mechanical and electrical shocks. Using the inverter drive can start smoothly (starting time becomes longer). The starting current is 1.2 to 1.5 times the rated current, and the starting torque is 70% to 120% of the rated torque; for the inverter with automatic torque enhancement function, the starting torque is more than 100%, and it can start with full load.

A: When the frequency drops, the voltage V also drops proportionally. Keeping the V/f ratio constant is the most basic control method for variable frequency speed regulation of asynchronous motors. The ratio V/f is constant, so that the magnetic flux of the motor remains constant. Under the rated operation of the motor, the voltage drop of the stator resistance and leakage reactance of the motor is relatively small, and the terminal voltage of the motor is approximately equal to the induced potential of the motor.
The constant V/f ratio control is often used in general-purpose inverters. This type of inverter is mainly used for the speed regulation function of fans and water pumps, as well as occasions where the speed regulation range is not high. The outstanding advantage of constant V/f ratio control is that it enables open-loop speed control of the motor.

A: When the frequency drops, the voltage is completely proportionally reduced, so the torque generated at low speed tends to decrease because the AC impedance becomes smaller and the resistance remains unchanged. Therefore, given V/f at low frequency, it is necessary to increase the output voltage to obtain a certain starting torque. This compensation is called enhanced starting. It can be realized by various methods, such as automatic method, selection of V/f mode, or adjustment of potentiometer.

A: The speed sensor is installed on the motor used, and the actual speed is fed back to the control device for control, which is called "closed loop", and the operation without the speed sensor is called "open loop". The general-purpose inverters are mostly open loop.

A: Output overload, output overcurrent, grid overvoltage, grid undervoltage, grid loss, DC bus overvoltage, DC bus undervoltage, transformer overheating, phase loss, control power failure, drive failure, power device overheating, cooling fan failure, the external given drop of high-voltage frequency converter, ground fault, optical fiber fault and so on.