JP2004015943A - Speed command setting method for electric motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed command setting method suitable for a motor variably driven by a motor drive such as an inverter. <P>SOLUTION: A circuit is constituted of an operation device 1, an input circuit 2, a multiplier 6, an adder 7, a limiter 8, an upper-limit setter 9, a lower-limit setter 10, an X<SB>1</SB>setter 21, a Y<SB>1</SB>setter 22, a X<SB>2</SB>setter 23, a Y<SB>2</SB>setter 24, and an operator 25. Two coordinates positions on a relational characteristic line between an input command-a speed command are taken as [X<SB>1</SB>, Y<SB>1</SB>] and [X<SB>2</SB>, Y<SB>2</SB>], and they are set to the circuit, thus embodying a relationship between a given input command value and speed command value. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a speed command setting method for a motor driven at a variable speed by a motor driving device such as an inverter.
[0002]
[Prior art]
FIG. 3 is a circuit configuration diagram showing a conventional example of a method for setting a speed command of a motor in this type of motor driving device.
[0003]
In FIG. 3, reference numeral 1 denotes an operating device for generating an external input command value, 2 denotes an input circuit for converting an input command value from the operating device 1 into an internal input command value [V], and 3 denotes a preset gain. setpoint gain setting unit for generating a [K _1], bias setting value set in advance 4 bias setting unit for generating a [K _2], the 5 later than the K ₁ and K ₂ [gain] and [offset 6 is a multiplier for obtaining a multiplied value of the [V] and the [gain], and 7 is a multiplied value from the multiplier 6 and an added value of the [offset] to an electric motor (not shown). The adder 8 derives the speed command value [N ^* ] of the speed command value [N ^* ] from the upper limit value [N _H ] preset by the upper limit setting device 9 and the lower limit setting device 10. limiting the range of that the lower limit value [N _L], this The limited value is a limiter to the new speed command value to the electric motor [N ^**].
[0004]
In the circuit configuration shown in FIG. 3, the speed command value [N ^* ], which is the output of the adder 7, is expressed by the following equation 1 based on the aforementioned [V], [K ₁ ] and [K ₂ ]. You.
[0005]
(Equation 1)
^{_{N * = K 1 · (1}} -K 2) · V + K 2
Here, the coefficient [K ₁ · (1−K ₂ )] of [V] in the first term on the right side indicates the [gain] output from the computing unit 5, and [K ₂ ] in the second term on the right side is the computing unit 5 shows the [offset] output from FIG.
[0006]
Further, an arbitrary voltage is given to the input circuit 2 as an input command value from the operating device 1, and the range of [V] output from the input circuit 2 is 10 V when the output voltage is 0 to 10 volts. The bolt has a value standardized to 1.0 (= 100%).
[0007]
Furthermore, the initial value of [N _H ] set in the upper limit setting device 9 is set to 100%, and the initial value of [N _L ] set in the lower limit setting device 10 is set to 0%.
[0008]
FIG. 4 shows an example of the relationship between the input command value [V] and the speed command value [N ^* ]. In the circuit configuration shown in FIG. 3, [K ₁ ] is set to 1.0 and [K ₂ ] Is a characteristic diagram when 0.2 is set to 0.2.
[0009]
Therefore, in the circuit configuration shown in FIG. 3 at the time of the characteristic diagram shown in FIG. 4, the speed command value [N ^** ] output from the limiter 8 is changed to the speed command value [N ^** ] output from the adder 7. ^* ].
[0010]
Further, FIG. 5, the input command value that is different from the FIG. 4 [V] and the speed command value shows an example of the relationship between [N ^*], in the circuit configuration shown in FIG. 3, 0 [K _1]. FIG. 7 is a characteristic diagram when 75 is set and [K ₂ ] is set to 0.2.
[0011]
Therefore, in the circuit configuration shown in FIG. 3 at the time of the characteristic diagram shown in FIG. 5, the speed command value [N ^** ] output from the limiter 8 is changed to the speed command value [N ^** ] output from the adder 7. ^* ].
[0012]
[Problems to be solved by the invention]
In the conventional circuit configuration shown in FIG. 3, the operation of setting the gain set value [K ₁ ] and the bias set value [K ₂ ] is relatively easy to implement the characteristic diagram shown in FIG. 4 or FIG. Is an example of the relationship between the input command value [V] and the speed command value [N ^* ] as shown in FIG. 6, for example, the gain setting value [K ₁ ] and the bias setting value [K ₂ ] It is necessary to derive from the simultaneous equations obtained from the characteristic diagram of FIG.
[0013]
(Equation 2)
1.0 = K ₁ · (1-K ₂ ) · 0.5 + K _{2
0.0 = K 1 · (1-} K 2) · 0.1 + K 2
That is, K ₁ = 2.0 and K ₂ = −0.25 are obtained. However, this setting operation requires a great deal of labor, and has a disadvantage that workability is poor.
[0014]
An object of the present invention is to provide a method for setting a speed command of an electric motor that solves the above problems.
[0015]
[Means for Solving the Problems]
In the first invention, a first input command value and a first speed command value corresponding to the input command value are set in advance, and a second input command value and a second speed command value corresponding to the input command value are set. A speed command value is set in advance, and based on the first input command value and the speed command value, and based on the second input command value and the speed command value, an electric motor corresponding to an input command value externally supplied to the motor. The speed command value of the motor is calculated, and the speed of the motor is controlled based on the calculated speed command value.
[0016]
According to a second aspect of the present invention, there is provided the motor speed command setting method according to the first aspect,
The calculated speed command value is limited to a range between a preset upper limit value and a lower limit value, and the limited speed command value is set as a new speed command value for the electric motor.
[0017]
According to the present invention, by reading and setting two sets of coordinate values on the characteristic diagram from the predetermined characteristic diagram of the input command and the speed command, the required input command value and the speed command value can be determined. The relationship can be easily realized.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a circuit diagram showing an embodiment of a method for setting a speed command of a motor according to the present invention. Components having the same functions as those of the conventional circuit shown in FIG. Description is omitted.
[0019]
That is, the circuit configuration is different from the gain setting device 3 shown in FIG. 3 is the circuit structure shown in FIG. 1, the bias setter 4, instead of the calculator 5, and X ₁ setter 21, Y ₁ setter 22 is that it is provided with _{X 2} setter 23, _{Y 2} setter 24, a computing unit 25.
[0020]
Figure in the circuit configuration shown in 1, the speed instruction value which is the output of the adder 7 and the ^{[N *]} of the foregoing is [V], the set value of _{X 1} setter 21 is preset _[X 1], _{Y 1} the set value of setter 22 _{[Y 1],} the set value of _{X 2} setter 23 is preset _[X 2], based on a _{Y 2} setter 24 setting _{[Y 2],} in equation (3) below expressed.
[0021]
[Equation 3]
^{_{N * = {(Y 2 -Y}} 1) / (X 2 -X 1)} · V
+ (Y ₁ · X ₂ -X ₁ · Y ₂ ) / (X ₂ -X ₁ )
Here, the coefficient of [V] of the first term on the right side indicates [gain] output from the arithmetic unit 25, and the second term on the right side indicates [offset] output from the arithmetic unit 25.
[0022]
That is, in the case of the example of the relationship between the input command value [V] and the speed command value [N ^* ] as shown in the characteristic diagram of FIG. 2 in the circuit configuration shown in FIG. 1, the coordinates [X ₁ , Y ₁ ] and the coordinates [X ₂ , Y ₂ ] of the point B, and by substituting them into the above equation (3), a speed command value [N ^* ] is obtained. Further, H _H = 100 %, And [Y ₁ · 100]% in _HL , a speed command value [N ^** ] to the motor (not shown) can be obtained.
[0023]
For example, when the relationship between the input command value [V] and the speed command value [N ^* ] is as shown in FIG. 4 described above, X ₁ = 0.0, Y in the circuit configuration shown in FIG. _What is necessary is to set ₁ = 0.2, X ₂ = 1.0, and Y ₂ = 1.0, and substitute them for the above equation (3).
[0024]
Therefore, in the circuit configuration shown in FIG. 1 at the time of the characteristic diagram shown in FIG. 4, the electric motor which is the output of the limiter 8 in which [N _H ] is set to 100% and [N _L ] is set to 0% speed command value to the [N ^**] is the same value as the speed command value [N ^*] is the output of the adder 7.
[0025]
When the relationship between the input command value [V] and the speed command value [N ^* ] is as shown in FIG. 5, in the circuit configuration shown in FIG. 1, for example, X ₁ = 0.0, Y _What is necessary is to set ₁ = 0.2, X ₂ = 1.0, and Y ₂ = 0.8, and substitute them for the above equation (3).
[0026]
Therefore, in the circuit configuration shown in FIG. 1 at the time of the characteristic diagram shown in FIG. 5, the electric motor which is the output of the limiter 8 in which [N _H ] is set to 100% and [N _L ] is set to 0% speed command value to the [N ^**] is the same value as the speed command value [N ^*] is the output of the adder 7.
[0027]
Further, when the relationship between the input command value [V] and the speed command value [N ^* ] is as shown in FIG. 6 described above, for example, X ₁ = 0.1 in the circuit configuration shown in FIG. , Y ₁ = 0.0, X ₂ = 0.5, and Y ₂ = 1.0, and these may be substituted into the above equation (3).
[0028]
Therefore, in the circuit configuration shown in FIG. 1 at the time of the characteristic diagram shown in FIG. 6, the electric motor which is the output of the limiter 8 in which [N _H ] is set to 100% and [N _L ] is set to 0% speed command value to the ^{[N **]} is the speed command value ^{[N *]} is the _{[N H]} and in the range of _{[N L],} the speed instruction value which is the output of the adder 7 ^{[N *]} and Have the same value.
[0029]
In the circuit configuration shown in FIG. 1, X ₁ = 0.0, Y ₁ = 0.0, X ₂ = 1.0, and Y ₂ = 1.0 are set as initial values, respectively. By setting N _H = 100% and N _L = 0% as initial values, the relationship between the input command value [V] and the speed command value [N ^** ] as initial settings is gain = 1.0, offset = 0.0, that is, a linear characteristic with a gradient of 1.0 from the origin.
[0030]
【The invention's effect】
According to the present invention, two sets of coordinate values are read from the characteristic diagram showing the relationship between the input command and the speed command, and these are set, thereby facilitating the relationship between the requested input command value and the speed command value. Can be embodied.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram showing an embodiment of a method for setting a speed command of a motor according to the present invention; FIG. 2 is an input command-speed command characteristic diagram for explaining the operation of FIG. 1; FIG. 4 is a circuit diagram showing a conventional example. FIG. 4 is an input command-speed command characteristic diagram for explaining the operation of FIGS. 1 and 3. FIG. 5 is an input command-speed command characteristic diagram for explaining the operation of FIGS. FIG. 6 is an input command-speed command characteristic diagram for explaining the operation of FIGS. 1 and 3;
DESCRIPTION OF SYMBOLS 1 ... Operation device, 2 ... Input circuit, 3 ... Gain setting device, 4 ... Bias setting device, 5 ... Calculator, 6 ... Multiplier, 7 ... Adder, 8 ... Limiter, 9 ... Upper limit setting device, 10 ... lower limit setting unit, 21 ... _{X 1} setter 22 ... _{Y 1} setter 23 ... _{X 2} setter, 24 ... _{Y 2} setter, 25 ... calculator.

Claims (2)

Setting a first input command value and a first speed command value corresponding to the input command value in advance;
Setting a second input command value and a second speed command value corresponding to the input command value in advance;
Based on the first input command value and the speed command value, based on the second input command value and the speed command value, calculate a speed command value to the motor corresponding to the input command value commanded from the outside,
A speed command setting method for a motor, wherein the speed of the motor is controlled based on the calculated speed command value. The speed command setting method for an electric motor according to claim 1,
The calculated speed command value is limited to a range between a preset upper limit value and a lower limit value, and the limited speed command value is set as a new speed command value to the motor. Command setting method.

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