Vf Control Method

V/F is abbreviated from voltage/frequency. V/F control is an induction motor control method which ensures the output voltage proportional with the frequency, so it maintains a constant motor flux, preventing weak magnetic and magnetic saturation phenomenon from happening. Vector control, also called field-oriented control (FOC), is a variable-frequency drive (VFD) control method in which the stator currents of a three-phase AC electric motor are identified as two orthogonal components that can be visualized with a vector. One component defines the magnetic flux of the motor, the other the torque. Although the method of vector control or field-oriented control has been introduced by Blaschke, there is intensive research still taking place in that area. In this model, simulation of speed control of induction motor is done using V/f method with the implementation of sinusoidal pulse width modulated signals fed to the inverter.

Vf Control Method

© 2009 Intel Corporation

  • Yu Zhao <yu.zhao@intel.com>
  • Donald Dutile <ddutile@redhat.com>

3.1. Overview¶

3.1.1. What is SR-IOV¶

Single Root I/O Virtualization (SR-IOV) is a PCI Express Extendedcapability which makes one physical device appear as multiple virtualdevices. The physical device is referred to as Physical Function (PF)while the virtual devices are referred to as Virtual Functions (VF).Allocation of the VF can be dynamically controlled by the PF viaregisters encapsulated in the capability. By default, this feature isnot enabled and the PF behaves as traditional PCIe device. Once it’sturned on, each VF’s PCI configuration space can be accessed by its ownBus, Device and Function Number (Routing ID). And each VF also has PCIMemory Space, which is used to map its register set. VF device driveroperates on the register set so it can be functional and appear as areal existing PCI device.

3.2. User Guide¶

3.2.1. How can I enable SR-IOV capability¶

Multiple methods are available for SR-IOV enablement.In the first method, the device driver (PF driver) will control theenabling and disabling of the capability via API provided by SR-IOV core.If the hardware has SR-IOV capability, loading its PF driver wouldenable it and all VFs associated with the PF. Some PF drivers requirea module parameter to be set to determine the number of VFs to enable.In the second method, a write to the sysfs file sriov_numvfs willenable and disable the VFs associated with a PCIe PF. This methodenables per-PF, VF enable/disable values versus the first method,which applies to all PFs of the same device. Additionally, thePCI SRIOV core support ensures that enable/disable operations arevalid to reduce duplication in multiple drivers for the samechecks, e.g., check numvfs 0 if enabling VFs, ensurenumvfs <= totalvfs.The second method is the recommended method for new/future VF devices.

3.2.2. How can I use the Virtual Functions¶

The VF is treated as hot-plugged PCI devices in the kernel, so theyshould be able to work in the same way as real PCI devices. The VFrequires device driver that is same as a normal PCI device’s.

3.3. Developer Guide¶

3.3.1. SR-IOV API¶

To enable SR-IOV capability:

V/f control method of ac drive
  1. Board kings free rolls. For the first method, in the driver:

V/f Speed Control Method

‘nr_virtfn’ is number of VFs to be enabled.

  1. For the second method, from sysfs:

Vf Control Methods

To disable SR-IOV capability:

V/f Control Method Of Ac Drive

  1. For the first method, in the driver:

  2. For the second method, from sysfs:

To enable auto probing VFs by a compatible driver on the host, runcommand below before enabling SR-IOV capabilities. This is thedefault behavior.

V/f Control Method Of Induction Motor

To disable auto probing VFs by a compatible driver on the host, runcommand below before enabling SR-IOV capabilities. Updating thisentry will not affect VFs which are already probed.

3.3.2. Usage example¶

Following piece of code illustrates the usage of the SR-IOV API.

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II.Introduction (PDF;0.1 M byte)
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9.Measures to satisfy the standards (PDF;0.9 M byte)
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Function manualApplied for
ATEX guideVF-AS1, VF-PS1
CC-LINK functionVF-AS1, VF-PS1, CCL001Z
CC-LINK functionVF-AS1, VF-PS1, CCL001Z1
Commercial/Inverter switchingVF-AS1, VF-PS1
Current and speed control gain adjustment methodVF-AS1, VF-PS1
DeviceNet functionVF-AS1, VF-PS1, DEV002Z
EtherNet/IP communication function manualVF-AS1, VF-PS1, IPE001Z
Explanation of functions for lift application (Adjustment method for braking functions)VF-AS1
Explanation of functions for lift application (Basic chapter)VF-AS1
Explanation of functions for lift application (Function of high-speed operation at low-load)VF-AS1
Modbus TCP option unit Function ManualVF-AS1, VF-PS1, MBE001Z
My functionVF-AS1, VF-PS1
PID control fucntionVF-AS1, VF-PS1
RS485 Communicating manualVF-AS1
Torque control functionVF-AS1
Traverse functionVF-AS1
VF-AS1 with V3 motor (PG feedback option: VEC007Z)VF-AS1

Option manualApplied for
Braking unitVF-AS1, VF-PS1
CC-LINK OptionVF-AS1, VF-PS1, CCL001Z1
DC choke kit installation sheetVF-AS1, VF-PS1
DeviceNet OptionVF-AS1, VF-PS1, DEV002Z
EMC plateVF-AS1, VF-PS1
EtherNet/IP communication option manualVF-AS1, VF-PS1, IPE001Z
Expansion IO Card Option 1VF-AS1, VF-PS1, ETB003Z
Expansion IO Card Option 2VF-AS1, VF-PS1, ETB004Z
Heatsink Outside Mounting KitVF-AS1, VF-PS1
Heatsink Outside Mounting KitVF-AS1, VF-PS1
Heatsink Outside Mounting KitVF-AS1, VF-PS1
LCD Remote KeypadVF-AS1, VF-PS1, RKP004Z
manual of dV/dt filterVF-AS1. VF-PS1
ModbusTCP option unit Instruction ManualVF-AS1, VF-PS1, MBE001Z
Optional Control Power Supply BackupVF-S15, VF-AS1, VF-PS1, CPS002Z
PG feedback board optionVF-AS1, VF-PS1
Remote KeypadVF-S15, VF-AS1, VF-PS1, VF-FS1, VF-S11, VF-nC3, RKP002Z
RFI filter (EMC filter)VF-AS1, VF-PS1
RFI filter (Foot mount type EMC filter)VF-AS1, VF-PS1
Sinusoidal filterVF-AS1, VF-PS1
USB-to-Serial Conversion UnitVF-AS1, VF-PS1, VF-FS1, VF-S11, VF-nC3, USB001Z

Parameter list
Parameter list (V154)
Parameter list for V150
Parameter list for VF-AS1
Parameter list for VF-AS1 (V130~V136: WP1,WN1 model)
Parameter list for VF-AS1 (V130~V136: WP1,WN1 model)

Compliance with UL Standard
Precautions of using 4-20mA input signal

Appication manual
Check and maintenance
Energy-saving effect with inverter driving for the control of Fans and pumps
Inverter Noise Countermeasures
Inverter's calorific value
Leakage Current
Motor-end Surge Voltage by Inverter Drive
Selecting capacity of inverter