Beijer Electronics AN-BEI-P2-050 User Manual

APPLICATION NOTE AN-BEI-P2-050

Date: 15/02/12

AN-BEI-P2-050 Open Loop Permanent Magnet Motor Control

BFI Applications Support Library

Application Note

AN-BEI-P2-050

Title

Open Loop Permanent Magnet Motor Control

Related Products

Beijer Frequency Inverter P2

Level

1 – Fundamental - No previous experience necessary 2 – Basic – Some Basic drives knowledge recommended 3 – Advanced – Some Basic drives knowledge required 4 – Expert – Good experience in topic of subject matter recommended

Overview:

This document provides an overview of the operation of the Beijer Frequency Inverter P2 when used for open-loop permanent magnet (PM) motor control. Beijer Frequency Inverter P2 continues the design philosophy of ‘easy to set-

up’ and ‘high levels of performance’ into PM motor applications through simplification of the parameter set and

intelligent and accurate auto-tuning functions.

Applications:

PM motor control is provided as standard on the Beijer Frequency Inverter P2. In order to simplify the user manual PM motor parameters have been excluded and this application note is provided as the addendum for this function. The objective of using a PM motor in combination with Beijer Frequency Inverter P2 is to realize the high efficiency and savings, in combination with smooth and responsive performance, and smaller motor frame sizes, which can be achieved. Beijer Frequency Inverter P2 provides open loop PM motor control, there is no facility for operation of PM motors in closed loop or for any internal positioning functionality. The Beijer Frequency Inverter P2 PM Control algorithm is suitable for both Surface mounted (SPM) and rotor inbuilt (IPM) permanent magnet motors. Brushless DC motor control is realizable but it is important to first consult technical support for additional data and advice.

APPLICATION NOTE AN-BEI-P2-050

Date: 15/02/12

AN-BEI-P2-050 Open Loop Permanent Magnet Motor Control

Par.

Description

Range

Units

Default

Explanation

P1-14

Extended menu access

Code 0 to 30000

--- 0 Set to ‘201’ for access to PM motor control parameters. PM motor selection setting (in P4-01) and menu 7 are not visible when other value (than 201) is set.

P4-01

Control Mode

0, 1, 2: See Std Guide 3: PM Motor Control

--- 2 Selects the motor control method. Set to ‘3’ for Sensor-less PM motor control

P7-01

Stator Resistance

0.000 – 50.000

ohm

2.8

Motor Stator Resistance (phase –phase). Measure with ‘auto-tune’ or enter manually.

P7-03

Lsd Phase Inductance

0.0000 – 1.0000

Henry

0.13

Inductance Per Phase.

‘d’ component of armature winding inductance from

the d-q linear model. Measure with ‘auto-tune’ or enter manually.

P7-06

Lsq Phase Inductance

0.0000 – 1.0000

Henry

0.13

Inductance Per Phase.

‘q’ component of armature winding inductance from

the d-q linear model. Measure with ‘auto-tune’ or enter manually.

P7-10

Inertia Ratio

0 - 100

System Load Inertia to Motor Inertia Ratio. Entered into P7-10 as:

P7-10 = (J

Tot

/ J

Mot

) . 10

P7-12

Current magnetising time

0 - 2000

Motor magnetising time at start. Time following drive enable to establish magnetising flux in motor windings in order to accurately phase motor shaft.

P7-14

Boost Current Level

0 - 100 % 0

Boost current applied at start-up, as % of motor rated current (P1-08)

P7-15

Boost Frequency

0 – 50 % 0

Frequency range for applied boost current (P7-14) as % of motor rated speed (P1-10)

Firmware Overview – Additional Parameters and Settings:

Additional Parameter information to that provided in the standard Beijer Frequency Inverter P2 manual is as follows:-

APPLICATION NOTE AN-BEI-P2-050

Date: 15/02/12

AN-BEI-P2-050 Open Loop Permanent Magnet Motor Control

Par.

Description

Range

Units

Default

Explanation

P1-03

Acceleration ramp time

0 – 3000.0

Sec

5.0

Acceleration ramp time from 0 to base speed (P1-09) in seconds

P1-04

Deceleration ramp time

0 – 3000.0

Sec

5.0

Deceleration ramp time from base speed (P1-09) to standstill in seconds

P1-07

Nominal back emf

0 – 250 / 500

Volts (rms)

Phase – Phase voltage imposed by magnets while motor rotating at motor rated speed (P1-10)

P1-08

Motor rated current

25 – 100% of drive rated current

Amps

(rms)

0.13

Rated (nominal) phase current of the motor (used for over-current protection)

P1-09

Motor rated frequency

25 – 500

0.13

Rated (nominal) frequency of the motor.

P1-10

Motor rated speed

0 – 60,000

Rpm

Rated (nominal) speed of the motor.

P2-24

Switching frequency

4 - 32

kHz

Model

Based Value

Effective Power Stage switching frequency. Higher frequencies give smoother operation but care must be taken to apply necessary de-rate factors.

P4-02

Motor parameter auto-tune

0: Disable 1: Enable

--- 0 When set to 1 the drive will perform an auto-tune immediately of exiting the parameter. Values will be written automatically to parameters P7-01, P7-03, & P7-06.

P4-03

Speed Controller proportional Gain

0.0 – 400.0

25.0

Sets the proportional gain value for the speed controller. Higher values provide better output frequency regulation and response. Too high a value can cause instability or even over current trips. For applications requiring best possible performance, the value should be adjusted to suit

the connected load.

P4-04

Speed Controller integral time constant

0.000 – 1.000

0.500

Sets the integral time for the speed controller. Smaller values provide a faster response in reaction to motor load changes, at the risk of introducing instability. For best dynamic performance, the value should be adjusted to suit the connected load.

P4-07

Maximum motoring Torque limit

P4-08 – 200

200

When P4-01 is set to 3, sets the maximum torque limit.

P4-09

Maximum generating Torque limit

0.0 - 200

200

Sets the maximum regenerating torque limit permitted by the drive.

Firmware Overview – Standard Parameters for PM motor set-up:

The following parameters are taken from the main Beijer Frequency Inverter P2 user manual but are required for set-up / configuration of a PM motor. Parameters highlighted in ‘Blue’ are essential for successful PM motor control with the Beijer Frequency Inverter P2. They are not configured during the auto-tune function and must be entered manually:-

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