Hitachi AN072302-1 User's Guide

Application Note for Vector Control with the SJ300 Inverter

Contents

[1]Overview

[2]How to Tune Each Parameter

(2-1) Tuning target of each parameter (2-2) SLV Control block diagram (2-3) V2 Control block diagram

(2-4) Standard motor parameter settings for SJ300 (400V class EU version) series inverter (2-5) Example of tuning effects (SLV mode)

[3] Positioning Under ASR mode (Orientation Function)

(3-1) Orientation Function

(3-2) Example of positioning under speed control mode (ASR) on SJ300 with SJ-FB (3-2-1) Example of wiring

(3-2-2) Example of parameter settings (3-2-3) Timing chart

[4] APR Control

(4-1) Example of parameter settings

(4-2) How to adjust control parameters for APR control

[5] Master Slave Control

(5-1) Example of parameter settings for Master-Slave control

(5-2) How many slaves can be connected?

(5-2-1) Parallel connection (5-2-2) Series connection

(5-3) Explanation of each P parameter

(5-4) Explanation of each output related to V2 control

Appendix A Calculation of total inertia (reflected to the motor shaft)

(A-1) Ventilation Fan (A-2) Truck

(A-3) Conveyer

Appendix B Calculation of load inertia

(B-1) A column (B-2) A cylinder

(B-3) A rectangular solid (B-4) A Cone

(B-5) Wind up (vertical linear motion) (B-6) Horizontal linear motion

This document is a guideline for optimizing motor/inverter performance in vector mode through parameter adjustments. Please note that actual performance of the motor depends on a combination of many parameters, and is difficult to describe concisely. Trial & error is the customary means to achieve good motor performance. Therefore please regard this information as just a guide only.

This document only shows technical issues related to vector control. Please refer to the SJ300 Inverter and SJ-FB manuals for detailed information for installation and operation.

[1] Overview

This engineering note applies when using SLV, 0-SLV and V2 (closed loop) control. It is often difficult to get optimized motor performance because many parameters interact. Please refer to this document for

getting a rough idea how to achieve good motor performance with above control modes. Please also note that the performance WILL NOT BE like a servo drive even in the case of V2 mode.

There are 3 basic modes with which you can get high torque performance with the SJ300 inverter:

(1) SLV control (No SJ-FB is used)

High motor torque performance with open loop can be obtained in the low frequency range (~0.5Hz). Please refer to a standard SLV block diagram in Fig 1 (section 2-2).

[H***] parameters are mainly adjusted for the control.

(2) 0-SLV control (No SJ-FB is used)

High torque performance can be obtained at around 0Hz. This does NOT mean the motor shaft will be at a standstill. The motor rotates slightly to generate motor torque, since this is not a servo drive. Depending on the application and tuning, you may be able to get full torque with the motor at standstill. This control algorithm is different from SLV control.

[H***] parameters are mainly adjusted for the control.

Œ Frequency control block portion

Frequency

reference

I *

ωs

Output frequency

ωr*

ASR

ω1

Slip reference

1/s

Output phase

(PI)

ωs*

q axis current

Slip reference

reference

at 0Hz

Stability

control

ωr^

Speed

estimation

Change over

of control

• Voltage control block portion

Estimation of

Magnetizing current

q-axis flux

Motor torque

Flux

id**

d-axis

id*

d-axis current

reference

ACR

calculation of

Vd*

Output

Torque current

ω1

Voltage Vector

voltage

q-axis

Vq*

iq*

ACR

Feedback current

(3) V2 control (SJ-FB is used)

High torque and stable, accurate motor performance can be achieved with the SJ300 in vector mode. A motor encoder and a feedback option card for SJ300 (SJ-FB) are needed to use this control mode. There are two regulation modes within the V2 control mode: ASR mode and APR mode .

Œ ASR mode : Inverter is controlled by speed command input (digitally set, analog input, or RS485)

• APR mode : Inverter is controlled by pulse train input signal

[H***] and [P***] parameters are adjusted for achieving good motor control.

A suitable mode should be selected depending on the application.

[Difference between each control]

ØControl performance

Item	SLV mode	V2 mode
Speed linearity	<1 %	<0.01 %
Speed fluctuation	<1 %	<0.01 %
Control range	1 : 50	1 : 100
Speed response	15 rad/s	60 rad/s
Torque control range	1 : 50	1 : 100
Torque response	50 rad/s	500 rad/s

sNote: These are representative values only.

sPercentages are relative to base speed

ØTorque performance at low speed

Item	SLV control	0-SLV control	V2 control
Down sized motor	150% or more	150% or more	150% or more
Same kW motor	100% or more	100% or more	100% or more

sThese are guaranteed minimum values with a Hitachi standard induction motor. Actual capability is greater.

ØTorque performance at 0Hz

Item	0-SLV control	V2 control
Down-sized motor	150% or more	150% or more
	with a small slip	with standstill
Same kW motor	100% or more	100% or more
	with a small slip	with standstill

sThis has been confirmed using Hitachi standard induction motor and J2 motor (for V2 control).

[2] How to tune each parameter

(2-1) Tuning target of each parameter

There are many parameters, which influence the motor performance in SLV, 0-SLV & V2 control modes. In some cases auto tuning is not fully sufficient to get the best motor performance because there are various kinds of motors in the world. It is sometimes necessary to adjust by hand after the auto tuning.

Generally the performance of the motor can be determined from two criteria:

ØTorque performance at low speed

ØSpeed response against target speed

Table 1 shows main parameters that influence the motor performance inSLV mode. The concept is the same in 0-SLV and V2 modes as well.

Table 1. Explanation of parameters related to motor performance in SLV mode

Code			Function				Remarks
H001	Auto tuning mode					This determines the method of auto tuning.
		R1		L		00 (NOR) : Auto tuning invalid
		R1		L	R2	01 (NRT) : Auto tuning with motor at standstill
						02 (AUT) : Auto tuning with motor rotation
						02 (AUT) : Auto tuning with motor rotation
					LM	Auto tuning determines the following motor constants


						automatically. (See left figure as well.)
						automatically. (See left figure as well.)
	Equivalent circuit of one leg of					Ÿ	R1 (primary resistance)
	the motor winding					Ÿ	R2 (secondary resistance)

ŸL (leakage inductance)

ŸIo (magnetizing current at base frequency)

ŸJ (total load inertia)

					Normally better motor performance can be obtained by auto tuning
					with motor rotation with an actual load on the motor. But if the
					system does not allow rotating the motor, like a lift application for
					example, auto tuning with motor at standstill can be used.
H002	Motor constant selection				This determines which set of motor parameters is used by the drive.
						00 : Motor parameters for a Hitachi standard motor
						(Uses [H020] ~ [H024] )
						01 : Use auto tuning data
						(Uses [H030] ~ [H034] )
						02 : Use auto tuning data with On-line auto tuning
					On-line auto tuning occurs every time the inverter stops. It
					measures R1 and R2, the main values that may change
					due to a motor temperature change. The tuning period is roughly
					5 seconds maximum, and if the RUN command is given during
					the tuning routine, the inverter will start and tuning is aborted.
H003	Motor kW				This sets the motor kW, not a kW of an inverter.
H004	Motor poles
H005	Speed response factor K				Controls the speed response
					Ÿ	Large K à Quick response (Too high a value can cause instability.)
					Ÿ Small K à Slow but stable response
					Value is also dependent on Proportional gain (P-gain : [H050])
					and Integration gain (I-gain : [H051]). ( K = f(Kp, Ki) ).
H006	Motor stability control factor				This should be adjusted in case of motor instability.
					Increase / decrease depends on the situation.
H020 / H030	Primary resistance of the				Influences mainly the torque at low speed.
	motor R1 [Ω]				Ÿ	Large R1 à Higher torque (Too high R1 à Over magnetizing)
					Ÿ	Small R1 à Smaller torque
H021 / H031	Secondary resistance of the				Influence mainly on the speed change ratio (= slip compensation)
	motor R2 [Ω]		ideal		Ÿ	Large R2 à Increase speed change ratio
	Torque					(= Actual speed becomes faster than a target speed.)
						(= Actual speed becomes faster than a target speed.)
		Small		Big R2	Ÿ	Small R2 à Decrease speed change ratio
				Big R2	Ÿ	Small R2 à Decrease speed change ratio
						(= Actual speed becomes slower than a target speed.)
		R2				(= Actual speed becomes slower than a target speed.)
		R2


				Speed

Code	Function				Remarks

H022 / H032	Leakage inductance	of	the	L does not influence control much compared to other
	motor L [mH]			parameters, however a suitable value is recommended to be set.
H023 / H033	Magnetizing current	of	the	Influences mainly the torque at low speed.
	motor Io [A]			Ÿ	Large Io à Bigger torque (Too big Io à Over magnetizing)
				Ÿ	Small Io à Smaller torque
H024 / H034	Total inertia J [kgm2]			Influences mainly speed and torque response performance
				This should be the total inertia (Σ J) on the motor shaft,
				including the inertia of the rotor of the motor and the load. See
				table 2 for information on how to tune in each case.
				à See appendix A for calculation of the total inertia.
H050	Proportional gain under			Fine tuning of proportional portion of speed response factor.
	PI control mode (Kp)			Ÿ	Large Kp àQuick response (Too high Kp can cause instability.)
	(% based on [H005])			Ÿ	Small Kp à Slow but stable response
H051	Integration gain under			Fine tuning of Ki portion of speed response factor.
	PI control mode (Ki)			Ÿ	Large Ki à Quick response (Too high Ki can cause instability.)
	(% based on [H005])			Ÿ	Small Ki à Slow but stable response
H052	Proportional gain under
	P control mode (Kp)
	(% based on [H005])
F002	Acceleration time			Acc and Dec time influence the response. Even if
F003	Deceleration time			optimized tuning parameter values are set, actual motor speed will
				change according to the set ramp time.
				If a quick response is required, the ramps should be set as fast as
				possible. Or, use LAC (LAD cancellation) to make the ramp invalid.
A044	Control mode			Control mode should be set to 03 (SLV), 04 (0-SLV) or 05 (V2).
A045	Output gain (Vgain)			Output gain scales the duty cycle of PWM output, regardless of
				the input voltage of the inverter.
				Decreasing output gain can solve the problem of motor instability,
				however the output torque will also decrease in this case.
A081	AVR function			AVR function attempts to maintain a stable output voltage by
				changing the duty cycle of the PWM output in real-time. If the input
				voltage changes or bus voltage changes due to regeneration, motor
				sees constant voltage. That means the motor efficiency will be better.
				In some cases, disabling the AVR function can resolve motor
				instability problems.
				AVR function attempts to always mainain constant output voltage.
				During operation, DC bus voltage is always changing, which
				means AVR function is always acting to change the duty cycle of
				PWM output voltage. Since it is an active control function it may
				lead sometimes motor instability (unstable energy transmission).
				In such cases, setting AVR OFF can solve the problem.
b022	OL restriction level			Set OL level [b022] as high as possible, or else disable it
				(set [b021] to “00 ”), because a rather high motor current is
				required in low frequency area in the case of vector control.
				High torque cannot be achieved if OL restriction is preformed.
b041~b044	Torque limit level			Set torque limit level as high as possible, or else disable it
				( = assign TL to an intelligent input terminal and leave it OFF),
				because high motor current is required in the low frequency area
				in the case of vector control.
				Maximum torque cannot be achieved if torque limit is triggered.
b083	Carrier frequency			Decreasing carrier frequency can solve the problem of motor
				instability.
				This is because the effect of dead time will be reduced.

*Second and 3rd functions ([H2**] & [H3**]) have the same meaning for 2nd and 3rd motors.

Refer to Table 3 for standard (default) motor parameter settings for SJ300 series inverter.

Table 2 shows suggestions for adjusting the SLV and other related parameters to correct various phenomena.

Table 2. Suggestions for tuning

#	Phenomena	Parameter	How to adjust

1	Actual speed is faster than the target speed.	H021	Decrease R2 value
1	(Speed deviation is +)	H021	(Minimum target is 80% of the preset value)
	(Speed deviation is +)		(Minimum target is 80% of the preset value)
2	Actual speed is slower than the target speed.	H021	Increase R2 value
2	(Speed deviation is - )	H021	(Maximum target is 120% of the preset value)
	(Speed deviation is - )		(Maximum target is 120% of the preset value)

	Insufficient torque at low speed (~ few Hz)	H020	Increase R1 value
	Insufficient torque at low speed (~ few Hz)	H020	(Maximum target is 120% of the preset value)
3			(Maximum target is 120% of the preset value)
3		H023	Increase Io value
			Increase Io value
			(Maximum target is 120% of the preset value)
			(Maximum target is 120% of the preset value)

4	Shock at start	H024	Decrease J

5	Unstable motor rotation	H005	Decrease speed response factor

		H024	Decrease J

		H006	Increase / decrease stability control factor
		H006	(Increase or decrease depends on the situation.)
			(Increase or decrease depends on the situation.)
		A045	Decrease output gain

		A081	Set AVR function to OFF

		b083	Decrease carrier frequency

6	Insufficient torque at low speed due to torque	b021,	Set;
	Insufficient torque at low speed due to torque	b041	Set;
	limit action	b041	Torque limit level > Overload restriction level
	limit action	~b044	Torque limit level > Overload restriction level
		~b044
		H005	Increase speed response factor
7	Response is slow
7	Response is slow	H050	Increase P-gain of speed response factor

		H051	Decrease I-gain of speed response factor

		H005	Decrease speed response factor
8	Speed overshoot due to too quick
	Speed overshoot due to too quick	H050	Decrease P-gain of speed response factor
	response	H050	Decrease P-gain of speed response factor
	response

		H051	Increase I-gain of speed response factor

*Refer to Table 3 for a standard (default) motor parameter settings for SJ300 series inverter.

SLV Control block diagram (Fig 1)

Motor

Speed response [H005]

P gain for PI [H050]

I gain for PI [H051]

Motor Constant

P gain for P [H052]

(R1, R2, L, Io)

[H070], [H071], [H072]

ωr*

Motor Constant (R1,L,Io,J)

vU* vV* vW*

Speed

Speed reference

iq*

ωr^

control

vq*

id*

Voltage calculation

Voltage conversion

Magnetizing

(Interference control)

vd*

current reference

(2φà3φ)

φd*

Motor Constant

(R1, R2, L, Io)

Magnetizing

current Io

ω1*

iq*

Torque current

vq0

control

(q-ACR)

Motor Constant

(R1, R2, L, Io)

Compensation

(R1, R2, L, Io)

id*

voltage

Magnetizing

calculation

current control

vd0

(d-ACR)

Stabilization

factor [H006]

id*

d-axis secondary

φd*

iq*

Frequency

ω1*

Integrator

calculation

flux control

Motor Constant

(R1, R2, L, Io)

Current converter

φd*

(3φ à2φ )

ωr^

Speed

ω1*

estimator

Motor Constant

(R1, R2, L, Io)

Vector control technical information

						Inverter main body
LAC				Internal
				Internal
				setting		TH
	APR	LAD	ASR	Torque	ACR	PWM	M
	APR	LAD	ASR	limiter	ACR	PWM	M
				limiter
PCLR
				Speed
POK				detection		SJ-FB	EC
					Position		EC
					Position
ORT	Orientation				detection	EAP,EAN
	control					EBP,EBN
						EBP,EBN
						EZP,EZN
						EP5,EG5
STAT		Speed deviation	Zero speed			AP,AN
		Speed deviation	Zero speed			BP,BN
		excessive signal	detection			BP,BN
		excessive signal	detection
						SAP,SAN
						SBP,SBN
		DSE	ZS

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