Frequency Inverter (Open Loop Vector Control AC Drive)

KE 300 frequency inverter provides a great way of adjusting motor speed and torque by changing the motor frequency. Frequency is directly related to the motor speed. Simply put, the faster the motor frequency, the faster the motor goes.

Traditional scalar drives lack accuracy in control due to the fact that they only control the ratio of voltage to frequency, or the V/F ratio for short. On top of that, these drives only tell the motor what to do but they have no way of knowing whether the motor does it or how well it does it.

KE300 frequency inverter is essentially a vector control AC drive or VFD that uses advanced vector control to dynamically determine the values of motor frequency and voltage. A sensor-less method used to send motor-related feedback information to the PID controller of the VFD for monitoring and analyzing the motor performance. That is why this series of VFD is sometimes called the sensor-less vector control variable frequency drive or open loop vector control AC drive.

Typical uses of our frequency inverter are in fans, water pumps or any other applications that require high energy efficiency, accurate speed regulation, quick response to sudden changes in load torque, and generating large torque at low frequency.

Features of KE300 Frequency Inverter
1. Sensorless Vector Control
Sensorless vector control allows the frequency inverter to put out 150% of the rated torque at 0.5Hz frequency. This control technique improves the flexibility of VFD in coping with changing motor loads. Our motor speed controller can be used for accurate tension control in the winding process, and overcomes the problem of uneven load distribution among multiple motors used to pull the same load.

2. Overload Protection
When the motor reaches a certain limit, the variable frequency drive only allows the motor to change its frequency without further increasing the torque when dealing with heavy duty tasks. This overload protection feature protects mechanical equipment and keep the entire operation up and running.

3. Fast, Dynamic Response to Changes in Load Torques
Dynamic response time is less than 20ms under vector control without using pulse generator.

4. Quick Current-Restriction
This feature can quickly limit the current within the allowable range, thereby avoiding alarm of over current caused by sudden addition of loads or disturbances. Our variable frequency drive reduces the possibility of frequent alarm of over current to ensure safety of our adjustable frequency drive.

5. Accurate Parameters Identification
Automatic fine-tuning of motor parameters according to the changing load conditions.

6. High Precision Torque Control
Torque control can be achieved under sensorless vector control mode. The control accuracy reaches ±10%, making it easy to complete tension control of a winch by using the frequency inverter.

7. AVR Function
When the voltage of the power grid changes, our variable speed drive can keep its output voltage constant, efficiently resolving issues of low frequency oscillation of high-power motors.

8. Dual PID Switching Function
The vector control variable frequency drive comes with two sets of PID parameters, which make it convenient to achieve close loop process control.

9. KE300 has many other powerful functions.
Please check KE300 Catalogue and KE300 User Manual for more details.

Control Functions
1. Common DC Bus: Multiple open loop vector control AC drives can share a common DC bus and their capacities are automatically balanced.
2. Torque Control: Torque control without PG is adopted.
3. Overload Protection: During operation, torque is automatically limited to prevent frequent tripping caused by over current.
4. Fault Protection: Our adjustable-frequency drive provides protection in times of fault such as overcurrent, overvoltage, undervoltage, phase loss, overload, short circuit, etc. Detailed information of operation status of the inverter is recorded. The product also has automatic recovery function.

Human Machine Interface
1. LED Display: It can show reference frequency, output frequency, output voltage, output current, etc.
2. Multifunction Key: QUICK/JOG key can also be used as multifunction key.
3. Powerful Upper Computer Software: Micno upper computer software supports uploading and downloading between frequency inverter and PC as well as real-time display.

Environmental Restrictions
1. Temperature: -10°C ~40°C . Derating of the frequency inverter is necessary if working temperature is higher than 40°C and the working temperature can not exceed 50°C . The AC drive should be derated by 4% with an increase of 1°C in temperature.
2. Humidity: ≤90%RH, no moisture condensation
3. Altitude: ≤1000m: rated power output; >1000m: derated power output
4. Storage Temperature: -20°C~60°C
5. Storage Circumstance: indoor, no direct sunlight, dust, corrosive gas, combustible gas, oil mist, steam, drip, salt, etc

KE300 Frequency Inverter Overall Dimensions and Installation Hole Dimensions

Note: Standard variable speed drives with power ranging from 90kW to 200 kW have no base.

With high performance, KE300 variable frequency drive is widely used in a variety of occasions.