E6581315

6.1. Proportional control of speed

Proportional control of frequency can be performed in two ways: control by selecting frequency points and control by adjusting the ratio to the maximum frequency. This section explains propor- tional control of inverters by means of a master inverter (inter-drive communication), although the AS1 series inverters are ready for proportional control by means of the “S” command even when they are operated under the control of a computer (computer-linked communication) (in the latter cases, read the master inverter as the computer).

Proportional control can also be performed in units of Hz using ordinary write commands (W and P commands) (frequency point selection only). For proportional control in units of %, however, the S command should be used.

*For proportional control by selecting frequency points, the gradient can be set variously according to the way each inverter is used. For proportional control by controlling the ratio to the maximum frequency, settings can be made easily without consideration of the rate at which the frequency is increased or decreased to the target frequency.

•Data sent by the master inverter to slave inverters in inter-drive communication mode (frequency command value)

fc(%)＝

Master side fc×10000

(1=0.01%)

Master side FH

 

 

*Fractions under 1 (0.01%) are omitted. Therefore, an error of 0.01% is introduced at the maxi- mum.

•Conversion of the frequency command received by a slave inverter (when the “frequency point selection” option is not selected)

The value obtained by the following conversion calculation is written in RAM as a frequency com- mand value.

fc( Hz ) =

Slave receive data(%)⋅ Slave side FH

(1=0.01Hz)

10000

 

 

*Fractions under 1 (0.01Hz) are omitted. Therefore, an error of 0.01Hz is introduced at the maxi- mum.

[Diagram of speed proportional control]

<Outside> ← →<Inverter's internal computation>

Operation performed

by the

Operation performed by the slave

master (or use of S command)

 

 

 

 

 

 

 

 

 

 

 

 

 

Master send data＝

Master fc

 

⋅ 10000

 

%

Data ( Hz )＝

Slave receive data

⋅ Slave FH

Master FH

 

10000

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

%

* fc=frequency reference, FH=maximum frequency

 

 

Point selection ()

Fc (Hz)

Hz

Points not selected

 

Point conversion

 

 

 

 

 

 

 

 

 

 

 

Points selected

 

(Hz)

 

 

 

 

 

 

Setting 2 fc ()

 

 

 

 

 

 

Slave command

 

 

 

 

 

 

Setting 1 fc ()

 

 

 

 

 

 

Point1

Point2

(%)

 

 

()

()

 

 

 

 

 

 

Master command

 

 

 

Point 2fc − Point1fc

⋅( Mastercommand－Point1）＋Point1fc

Hz

 

Slave command＝ Point2− Point1

 

 

Hz

fc

 

 

 

 

 

Data＝SlaveFH⋅10000

 

%

 

 

 

 

 

 

 

 

37

 

 

 

 

 

 

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Toshiba RS485, VF-AS1 Series instruction manual Proportional control of speed, =0.01%
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RS485, VF-AS1 Series specifications

The Toshiba VF-AS1 Series represents a significant advancement in the realm of variable frequency drives (VFDs), designed for various industrial applications that demand precision, efficiency, and reliability. With support for RS485 communication, the VF-AS1 Series fosters seamless integration into complex automation systems, making it the perfect choice for modern manufacturing environments.

One of the standout features of the Toshiba VF-AS1 Series is its versatile communication capabilities. The built-in RS485 port allows for easy connectivity with a range of devices, including PLCs (Programmable Logic Controllers) and HMIs (Human-Machine Interfaces). This ensures real-time monitoring and control of motor functions, enhancing operational efficiency and data analysis.

The VF-AS1 Series is engineered with advanced control technologies that provide exceptional motor performance. It incorporates vector control algorithms that optimize torque and speed regulation for both standard and permanent magnet motors. This results in precise motor control across a wide range of speeds and load conditions, ensuring optimum performance and energy savings.

Another noteworthy characteristic is its user-friendly interface. The VF-AS1 features a clear LCD display that allows for easy navigation and configuration. This intuitive design minimizes the learning curve for operators and technicians, facilitating quick setup and adjustments. Additionally, the series supports various programming options, catering to both novice users and experienced professionals.

Energy efficiency is a key priority in the design of the VF-AS1 Series. The drives are equipped with energy-saving features that help reduce overall power consumption and operational costs. With built-in sleep modes and dynamic energy feedback, these drives optimize energy usage based on demand, making them suitable for both constant and variable load applications.

In terms of safety and protection, the VF-AS1 Series incorporates various built-in safeguards, including overvoltage, undervoltage, and overcurrent protection. This comprehensive approach to safety not only protects the drive itself but also ensures the longevity of connected equipment.

Overall, the Toshiba VF-AS1 Series, with its robust feature set, advanced technologies, and focus on energy efficiency, proves to be a reliable choice for a wide range of industrial applications. Its integration of RS485 communication allows for enhanced connectivity and control, making it an excellent solution for modern automation needs.
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