JPH01321893A - Controller of enclosed type compressor - Google Patents

Abstract

PURPOSE:To control vibration and to reduce the price of a device by generating a voltage reference signal or a current reference signal in accordance with a pattern set in advance under the information of a rotary angle. CONSTITUTION:A controller of an enclosed type compressor is constituted of a transistor inverter 2, a current power circuit 3, a voltage detector 4, a current detector 5, a rotary angle operation circuit 6, a speed reference generation circuit 8 and a current controlling circuit 10, and driving control of a brushless motor 1 is made. A current reference generation circuit 11 is provided thereto. The circuit 11 is constituted of an average speed operation circuit, a current pattern generation circuit and the like, variation between a speed reference value and an average speed estimate is obtained, and a current reference mean value is obtained through an amplification and the like. At that time, a value obtained through the addition of the current reference mean value to a current reference correction value by the current pattern generation circuit and the like is a current reference value. Accordingly, vibration of the compressor is controlled by inputting only the information of rotary angle and changing the generation torque according to the pulsating load torque.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a control device for a hermetic compressor, and in particular to a hermetic compressor control device that reduces vibrations of the compressor caused by pulsating load torque generated by compression operation by controlling the voltage or current supplied to the hermetic compressor. This invention relates to a control device for a compressor.

[Conventional technology]

FIG. 14 is a block diagram showing a control device for a conventional hermetic compressor, as shown, for example, in Proceedings of the National Conference of the Institute of Electrical Engineers of Japan in 1988 Nα676. In the figure, 1 is a hermetic compressor R (not shown). ), 2 is a transistor inverter circuit as a variable frequency power converter for driving the brushless morph 1 at a variable frequency, 3 is a DC power supply circuit, and 4 is a terminal voltage applied to the brushless motor 1. 5 is a current detector for detecting the current supplied to the brushless motor 1; 6 is a voltage detector for detecting the current supplied to the brushless motor 1 by inputting the terminal voltage outputted from the voltage detector 4, and detecting the current supplied to the brushless motor 1 by the method described below. 7 is a rotation angle calculation circuit 6 for calculating the rotation angle of
Based on the rotation angle signal output from the brushless motor
8 is a speed reference generation circuit, 9 is a speed control circuit, and 10 is a current control circuit. Next, the operation will be explained. First, a method of calculating the rotation angle of the brushless motor l using terminal voltage and a frequency control method using the transistor inverter circuit 2 will be explained. This method is reported, for example, in the literature (1982 Institute of Electrical Engineers of Japan National Conference Lecture Proceedings Nα542). FIG. 15 shows a specific configuration of the transistor inverter circuit 2. First, assuming that the brushless motor 1 is rotating at a certain constant speed, the terminal voltage Vu6 with respect to the reference potential of each stator winding in the u, v, and w phases. vv,. vw. The approximate waveform is as shown in FIG. 16(a). Note that Vdc is a DC input voltage value. These terminal voltages VuO~v,. When inputting these into the integrator, triangular wave signals Vuf+Vvf+vwf whose phases are delayed by 90' with respect to the terminal voltage are obtained, and when these Vuf"-"Vwf are inputted into the polarity discrimination circuit, 2 is obtained. Value code S. ISVHS
1/ is obtained. By the way, in order to rotate the brushless motor 1, the ON/OFF switch shown in FIG.
According to the signal, the six transistors U + , V shown in FIG. 15 configuring the transistor inverter circuit 2
+. w'', u-, v-, and w- must be turned on and ClFF, but for example, during the ON period of the transistor u1, the level of the binary signal Sv is “L′, and the level of the binary signal Sw
As in the section where the level of is "H", the binarization signal S,...
ON/OFF signals can be obtained by logical operations using S,,S,. Therefore, the terminal voltage vuf''' V
Turn on the transistor inverter circuit 2 using wf.
By determining the OFF operation, the brushless motor 1
It can be seen that frequency control is possible. Also, the 15th
As shown in the figure, there are six modes depending on the ON/OFF signals of the six transistors. Therefore, by determining in which mode the brushless motor 1 is currently operating, it is possible to detect the rotational electrical angle of the brushless motor 1 with a resolution of 90° (=360°/6) in terms of electrical angle. As is well known, the following equation holds between the rotational mechanical angle θr1 and the rotational electrical angle θ. θ, = P, θ, ......(1
) (P,; Number of pole pairs of brushless motor) Therefore, by converting to rotational mechanical angle, 60'/P
The rotor position of the brushless motor 1 can be detected with a resolution of . Therefore, the rotation angle calculation circuit 6 shown in FIG. 14 calculates the rotation angle of the brushless motor 1 according to the above method, and also calculates the rotation angle of the
Generates ON/OFF signals to be supplied to. In addition, brushless morph 1. A device in which a transistor inverter circuit 22 and a rotation angle calculation circuit 6 are combined is usually called a brushless DC motor, and it is well known that variable speed control of the brushless motor 1 can be performed by changing the DC input voltage Vdc. Home air conditioners and refrigerators usually use hermetic compressors, but the compression of refrigerant gas causes a pressure change inside the compressor, and this pressure change causes the brushless motor 1 to
is known to act as a load torque. Further, this load torque becomes a periodic pulsating torque that is synchronized with the rotation of the brushless motor 1, and the rotational speed of the brushless motor 1 fluctuates periodically due to the influence of this pulsating load torque. As a result, it is well known that vibrations occur in the compressor itself. In order to reduce speed fluctuations of the brushless motor 1 due to this pulsating load torque, the conventional device shown in FIG. 14 employs a repetitive control method as a control method for the speed control circuit 9. Next, the principle of repetitive control will be explained using the flowchart shown in FIG. First, in step Sl, 1 is set to ■, and R is set to J. Next, in step S2, the deviation Δω between the speed reference value ω- outputted from the speed reference generation circuit 8 and the estimated speed value Ω of the brushless motor 1 outputted from the speed calculation circuit 7 is determined. Next, in step S3, the array D(m) (m=
The value obtained by adding this Δω to the value of the first data D(1) of 1°2, . . . , n) is changed as the new value of D(I). Next, in step S4, the value obtained by multiplying the gain by 0 to the value of the third data D (T) is set as the current reference value i4c''.Next, in steps 85 to SIO
By performing the above processing, when the values of I and J each reach a value n corresponding to one revolution, it is set to -1, otherwise, 1 is added, and the above calculation is repeated. For example, when the brushless motor 1 has a brushing number P1 of 1, as shown in FIG.
As shown in j), when the mode changes from 1 to 6,
Since the brushless motor 1 rotates once, the value of n is 6. Further, the repeated calculations in the flowchart shown in FIG. 17 are performed every time the mode changes. As a result, the speed deviation Δω synchronized with the rotation of the brushless motor 1 is integrated and written in the array D (m). On the other hand, the current reference value i is Δω. An arbitrary phase relationship (however, resolution of 60°/P.) can be given to the integral waveform. Therefore, the value of J should be determined so that the speed fluctuation is minimized. In the conventional device shown in FIG. 14, this repetitive control n is realized by controlling the microcontroller. Next, in the apparatus shown in FIG. 14, it is known that the current 1 dc detected by the current detector 5 is approximately proportional to the torque generated by the brushless motor 1. Therefore, the torque generated by the brushless motor 1 can be controlled by controlling the current tae to follow the current reference value id in the current control circuit 10. By the way, since the estimated speed value Ω is theoretically obtained as the amount of change in the rotational electrical angle θ with a resolution of 60° obtained by the rotation angle calculation circuit 6, in order to improve the estimation accuracy of the estimated speed value Ω, A big problem is how accurately the rotational electrical angle θ1 can be detected. However, since the calculation of the rotational electrical angle θ is performed using the terminal voltage VuO + vV (1 + vWO) as described above, the voltage drop due to the resistance and inductance of the stator winding of the brushless motor 1 is calculated as θ1. In addition, in order to reduce speed fluctuations, it is necessary to change the generated torque of the brushless motor 1 according to the pulsating load torque, and as a result, the current ID needs to be changed according to the pulsating load torque. Therefore, as the speed fluctuation decreases, the change in current i increases, and as a result, the stator winding voltage drop also changes greatly, increasing the calculation error of θ.In order to solve this problem, , the speed calculation circuit 7 inputs the current reference value 1 de'' output from the speed control circuit 9, estimates the amount of rotation angle change due to the voltage drop of the stator winding, and outputs it from the rotation angle calculation circuit 6. The error in speed estimation was reduced by correcting the rotation angle.

[Problem to be solved by the invention] The conventional hermetic compressor control device is configured as described above, and the rotation angle calculated using the terminal voltage of the brushless motor is calculated using the voltage drop in the stator winding estimated using the current i dc. The rotation speed was estimated with high accuracy by correcting the amount of rotation angle fluctuation due to the rotation angle, and the vibration of the compressor caused by the pulsating load torque was suppressed by applying repeated control. There was a problem that the estimation calculation was complicated. For this reason, there have been drawbacks such as difficulty in configuring the control device using a low-cost microcomputer with slow calculation speed. This invention was made to solve the above-mentioned problems, and its purpose is to provide a control device for a hermetic compressor that can suppress vibrations of the compressor without performing complicated rotational speed calculations. . ′ [Means to solve the problem]

A control device for a hermetic compressor according to the present invention includes a voltage or current reference generation circuit that generates a voltage or current reference signal according to a preset pattern to change the generated torque of the compressor in accordance with a pulsating load torque. This is a means for reducing vibrations in the compressor.

[Effect]

The control device for a hermetic compressor according to the present invention is such that the voltage or current reference generating circuit inputs only the rotation angle information of the compressor and changes the generated torque of the compressor in accordance with the pulsating load torque. Since the reference signal is generated, the vibration of the compressor is suppressed accordingly.

[Embodiments of the invention]

An embodiment of the first invention will be described below with reference to the drawings. In FIG. 1, 1, 2, 3, 4, 5, 6°8.10 are the same as in the conventional device. 11 is a current reference generation circuit. Hereinafter, each component will be further explained while showing specific examples thereof. First, the current control circuit 10 will be explained. FIG. 2 shows an equivalent circuit of the brushless motor 1 in mode 1 shown in FIG. 16. In the figure, R,...
L. are the resistance and self-inductance of the stator winding, respectively. Also, eu8. eVs is an induced voltage, and is expressed by the following formula. However, k8; Induced voltage constant per − phase In mode 1, transistors U゛ and V− are energized as shown in the figure, so the terminal voltages vuo+vvo become Vdc and O, respectively, and the stator windings of U phase and ■ phase A current tus flows in the direction shown in the figure. At this time, the following equation can be obtained from the figure. Vac=2CRs+PLs)! us + e
us e vs ”' (3) However, P = d/dt
;Substituting equation (2) into differential operator (3)2 yields the following equation. vdc=2(R-+PL-) i us /J
k, ωrcos(θ7−60°) (4) Next, the torque τ generated by the brushless motor 1 in this mode is expressed by the following equation. ” a+ =KT! us (Sln θ, -5in
(θ, -120' ) = fJ K y i us
cos (θ-60@) scolding...(5) However, K
7 ;-Torque constant per phase Also, the equation of motion of the brushless motor 1 is a known torque, τ3 ;Since it is greater than the load torque, the brushless motor 1 in mode 1
The block diagram of is shown in Figure 3. By the way, from Fig. 16, mode 1 is 30'' ≦θ, ≦
Since it is an interval of 90”, 0.87≦cos (θ,
-60')≦1, and in Figure 3 /J Kt
cos(θ, −60′). If I'Jk, cos(θr-60°) is regarded as a constant on average, it becomes equivalent to a block diagram of a normal DC motor. Furthermore, as is clear from FIG. 2, in mode 1, the current lde detected by the current detector 5 is tus
matches. Therefore, it can be seen that Fc is approximately proportional to the generated torque τ. A block diagram similar to that shown in FIG. 3 can be obtained in other modes as well. In addition, in FIG. 2, when only the transistor U' is turned on and off at high frequency, Vdc is applied only during the ON time, so by changing the ratio of the ON time to the OFF time, the U-phase terminal voltage V can be adjusted. It can be seen that it is possible to vary the value of 0 within the range of O"'-v dc. Based on the above, an example of the current control circuit 10 shown in FIG. 4 can be considered. , 101 is a subtracter, 102 is an amplifier, 103 is a signal conversion circuit, and 10
31 is a ROM, 1032 is a comparator, 1033 is a sawtooth wave generation circuit, and 1034 to 1036 are AND circuits. Next, the operation will be explained. First, current reference signal 1
dc” and the actual current 1 (I
A subtracter 101 obtains the deviation i d - tac from c, and this deviation is further amplified by an amplifier 102 to obtain a voltage reference signal V, d. The signal conversion circuit 103 supplies ON/OFF signals su", s," to the six transistors of the transistor inverter circuit 2 so that the terminal voltage of the brushless motor 1 becomes equal to V, on average.
,sw'',s,-.This is a circuit that generates Sv-,S,-, and its operation is as follows.First, the ROM 1031 is a circuit that generates Sv-, S,-.
With S as the address, S+, St, S3+34
, Ss, and S6 are output, and their contents are as shown in FIG. For example, S,,Sv,Sw=L,L,H
When,s,,S,,S,,S,. S5. S, -H,L,L,L,H,L, and accordingly, transistors u4 and v- are turned on. In FIG. 16, Su, Sv, S, = L, L
, H, the mode is 1, and the transistors u+ and v- are accordingly turned on. This is the same in other modes, such as Su, Sv, S,
For address inputs, output signals S+, S2 . S3
．． S4. SS and S6 also change, and the ON/OFF state as shown in Figure 16 changes.
It can be seen that an OFF signal is obtained. Next, when the amplitude of the voltage reference signal v4 and the amplitude f5 of the sawtooth wave signal outputted from the sawtooth wave generation circuit 1033 are inputted to the comparator 1032, 2 as shown in FIG.
An output signal S1 of value level is obtained. From this figure f a
It can be seen that as the value increases, the H level sections of the three output signals increase. Therefore, this output signal S, and the ROM
AND circuit 103 with the signal SI output from 1031
4, a signal Su'' is output that turns on the transistor U* only when Sl is H (mode 1 or 2) and S is H. Also, the transistor U'''
The ON time of increases in proportion to the amplitude of v, c''. As a result, in mode 1 or 2, the U-phase terminal voltage v8
It can be seen that ゜ becomes equal to v de'' on average if the frequency of the sawtooth signal is made high enough.In other modes as well, the ON time of transistors u'' and w'' is determined by AND circuits 1035 and 1036. Therefore, in modes 3 and 4, the average value is ■9°, and in mode 5.6, it is Vyu. The average value of each becomes equal to Vdc''. Through the above operation, the current control circuit 10 sets i and C to 1 ac
7 shows a specific example of the current reference signal generation circuit 11 in the first embodiment shown in FIG. 1. In the figure, 110 is an average speed calculation circuit, and 111 is a subtraction circuit. 112 is an amplifier,
113 is a current pattern generation circuit, 114 is a multiplier, 11
5 is a coefficient unit, and 116 is an adder. First, FIG. 8 shows an example of the configuration of the average speed calculation circuit 110. 1111 to 1113 are differentiators, 1114 is an OR circuit, 1115 is a period measurement circuit, 1116 is an addition circuit, 11
17 is a reciprocal calculation circuit. Next, the operation will be explained. The binarized signals Su, Sv, and S obtained by the rotation angle calculation circuit 6 are each differentiated by a differentiator 1111.
, 1112, 1113, a pulse-like signal is output in synchronization with the rising and falling edges of the input signal. When these pulsed signals are input to the OR circuit 1114,
6P pulse signals SP are output per one rotation of the brushless morph 1. The period measuring circuit 1115 determines the period of this pulsed signal S9, and then the adding circuit 1
At 116, the rotation period T r m of the brushless morph 1 is obtained by adding the periods of 6P. Furthermore, the reciprocal calculation circuit 1117 calculates the following equation to calculate the average value Ω of the electrical rotation speed of the brushless morph 1 per rotation. is obtained. Oh,. =2πP, / Trm...
・・・・・・・・・・・・(7) Furthermore, the binarization numbers Su, S
v, S is equivalent to the output signal of a three-phase encoder that outputs a rectangular wave signal of 2P per phase and pulses/rotation, and there is a known method for calculating the average rotational speed from the rectangular wave signal of the encoder. Therefore, the period measurement circuit 1115. Addition circuit 1116. A detailed description of the configuration of the reciprocal calculation circuit 1117 will be omitted. Now, in FIG. 7, the speed reference value ωt and the average speed estimated value Ω output from the average speed calculation circuit 110. The subtracter 111 calculates the deviation from the current reference average value! This deviation is input to the amplifier 112 and amplified. When the current control circuit 10 controls the current idc of the brushless morph 1 to follow this current reference average value 1 dco'', I2 is steadily maintained regardless of the magnitude of the load torque.
,. corresponds to ω−. However, as is clear from the calculation of equation (7), the average speed calculation circuit. does not include speed fluctuations due to pulsating load torque, so speed fluctuations due to pulsating load torque cannot be reduced. On the other hand, when a hermetic compressor is used in an air conditioner or a refrigerator to compress refrigerant gas, a pulsating load torque τ acts on the brushless motor 1. The steady rough waveform of is fixed,
Rotating mechanical angle θ1 of brushless motor 1. It is known that, for example, the waveform as shown by the broken line in FIG. Now, considering the case where the number of pole pairs PII of the brushless motor 1 is 1, from equation (1), the rotational electrical angle θ1 and the rotational mechanical angle θ
, , are consistent. Furthermore, as mentioned above, the rotational angle calculation circuit 6 calculates the rotational electrical angle θ with a resolution of 60°, so the generated torque τ of the brushless motor 1 is expressed as the waveform shown by the solid line in FIG. If controlled so that they match, speed fluctuations due to the pulsating load torque τ8 will be minimized. In this figure, τ1 is τ. It is equal to the average value for each section of 60''.Furthermore, the maximum value τ of the pulsating load torque τ.3.lX and the average value τ.1. are almost proportional to each other. (=τ
When the deviation Δτm=τ1−τ, 1v from IIIIVII) is calculated, the result is as shown in FIG. 3(b). Also, the same figure (b)
Also shown is the mode obtained from the binary code 5urSv,S. (See FIG. 16) FIG. 10 shows an example of the configuration of the current pattern generation circuit 113. In the figure, 1131 is ROM, 1132 is D/A
It is a converter. Next, the operation will be explained. ROM1131 has 2
A pattern corresponding to a mode uniquely determined from the value codes S, , Sv, S is stored. This pattern is Δτ obtained from FIG. 9(b). The value of the ratio of Δτ, □ to Δτ, , /Δτ1, − (dimensionless ■). Therefore, when (S,, Sv, S,) is input to the ROM 1131 as an address, the digital amount Δτ1/Δτ1□ corresponding to each mode shown in FIG. 9(b) is obtained as an output. When this digital amount is input to the D/A converter 1132, Δτ u/Δτ, 61 analog S, will be obtained. Next, in FIG. 7, when the above St output from the current pattern generation circuit 113 and the current reference average value 1 deo'' output from the amplifier 112 are multiplied by the multiplier 114, and further input to the coefficient multiplier 115, A current reference correction value Δ14c'' is obtained as an output. This Δi4 is expressed by the following formula. However, K: is the constant of the coefficient multiplier 115. Here, the brushless motor 1 is controlled by the current control circuit 10.
Considering that the current 10 is controlled to follow the current reference value id, and that the current idc is approximately proportional to the generated torque τ, Δid obtained by equation (8) is expressed as shown in FIG. It can be seen that the current reference is proportional to Δτ1 in b). In addition, since 1 dco'' is a current reference proportional to the average value τ, 1v of the load torque τ8, Fig. 9C
From b), it can be seen that the constant of the coefficient multiplier 115 should be selected so as to satisfy the following equation. Therefore, the adder 116 calculates the current reference average value 1 de
If the sum of the current reference correction value Δidc and the current reference correction value Δidc is the current reference value id, a torque τmave equal to the average value τ, 1v of the load torque τ is generated by the brushless motor l due to l deo. It can also be seen that Δtae generates a torque Δτ equal to the pulsation of τ8−τ.□0.Next, an embodiment of the second invention will be explained with reference to the drawings. , 2, 3.4, and 6°8 are the same as those in the conventional device, and 103 is the same as the signal conversion circuit 103 included in the current control circuit 10 in the embodiment of FIG. 1. 12 is a voltage reference generation circuit. Next, an example of the configuration of the voltage reference generation circuit 12 is shown in FIG. 12. In the figure, 110 is the same as the average speed calculation circuit 110 included in the current reference generation circuit 11 in the embodiment of FIG. 121 and 127 are coefficient multipliers, 122 is a subtracter, and 123 is an amplifier. 124 and 128 are adders, 125 is a voltage pattern generation circuit, and 126 is a multiplier. Next, the operation will be explained. First, the speed standard When the value ωI is input to the coefficient multiplier 121, the first voltage reference value ■.' corresponding to the no-load induced voltage v0 is output.From FIG. 3, the constant 2 of the coefficient multiplier 121 satisfies the following equation You can choose K2≦/JK, ・・・・・・・・・
...00) The value of K2 can be determined more accurately by experiment. Next, the subtractor 12 calculates the deviation between the speed reference value ω,° and the estimated average speed value Ω7° output from the average speed calculation circuit 110.
2, and input this deviation to the amplifier 123 and amplify it to obtain the load torque τ. The average value of τ,,V. A second voltage reference value v that generates a torque according to
, 11 are output. Therefore, the voltage reference average value v aco'' obtained by the adder 124 is applied to the signal conversion circuit 10.
3 is the terminal voltage that is applied to the brushless motor 1. If the variable frequency power converter 2 is controlled so that Q ro becomes equal to 0', Q ro constantly matches ωt regardless of the magnitude of the load torque. However, the average velocity estimate Ω,. does not include speed fluctuations due to pulsating load torque, so speed fluctuations due to pulsating load torque cannot be reduced. By the way, if the torque generated by the brushless motor 1 includes, for example, Δτ1 of Φ in FIG. 9, speed fluctuations due to pulsating load torque can be reduced. Also, from Fig. 3, the torque constant KT of the brushless motor 1, the resistance Rs of the stator winding, and the self-inductance,
A voltage reference correction value ΔV dc'' corresponding to Δτ can be obtained by functional calculation using Δτ. FIG. 13 shows an example of the configuration of the voltage pattern generation circuit 125. 1252 is ROM, 1
253 is a D/A converter. Next, the operation will be explained. First, the analog average speed estimate Q re outputted from the average speed calculation circuit 110 is converted into a digital amount by the A/D converter 1251 . ROM
1252 contains binarization signals Su and Sv. S, and A/D:l output Dm of the inverter 1251, D-
+...A pattern corresponding to Do is stored. This voltage pattern corresponds to the maximum value V dell of the voltage component ΔVdc necessary to generate Δτ1 in FIG. 9(b).
The ratio value Δvdc/vdcmmx (
dimensionless quantity). In one embodiment of FIG. 11, the current reference value! ac'
is generated according to the current pattern, but since the current 1dc of the brushless motor 1 is approximately proportional to the generated torque τ1, there is no need to change the current pattern according to the estimated average speed value Dr6. However, when generating the voltage reference value Δvac'' according to the voltage pattern, a problem arises from the phase change due to the impedance R3+PLs of the stator winding in FIG. The phase delay Δθ of
-・” (II) Therefore, it is necessary to consider the phase delay Δθ due to speed change in the above pattern.
M1252 contains the binary signals Su, Sv, S, and the output of the A/D converter 1251, ,D, ,...',
S,,Sv,S,,D,,D,−,using Do. ..., Do is used as an address, and corresponding data is stored. Therefore, S,,,Sv. Even if the value of S8 does not change, the average speed estimate Q r. As the values of , D, . . . , Do change, the output of the ROM 1252 also changes. next,
The output of this ROM1252 is transferred to the D/A converter 1253.
By inputting Δvdc/Δv dcemX, an analog quantity Sv of Δvdc/Δv dcemX is obtained. Now, in FIG. 12, the voltage pattern generation circuit 125
When the above Sv outputted from the amplifier 123 and the second voltage reference value Vbi outputted from the amplifier 123 are multiplied by the multiplier 1 cello and further inputted to the coefficient unit 127, the voltage reference correction value Δv,c'' is outputted. This ΔVac'' is expressed by the following equation. ΔVdc" = ・M ・v," ・・・・・・
Q7) ΔV4 (mix However, K3 is the constant of the coefficient unit 127. Here, vpi is the average value τ of the load torque τ8. Since it is a voltage reference proportional to ava, the value of 3 for the constant of the coefficient unit 127 is expressed by the following formula. All you have to do is choose one that satisfies K.
・03) τ@@VQ Therefore, the voltage reference average value V dc is determined by the adder 128.
If the value obtained by adding o2 and the voltage reference correction value ΔVdc'' is the voltage reference value Vd, then the load torque τ is determined by v dco''. The average value τ. Torque τIII equal to avt+
VII occurs in the brushless motor 1, and Δv ac
”, it can be seen that a torque Δτ equal to the pulsation component τ.−τ.1v of τ is generated. In addition, in FIG. 11, when the DC voltage Vdc output from the DC power supply circuit 3 fluctuates, , the voltage reference value v4 output from the voltage reference generation circuit 12 according to its fluctuation.
It goes without saying that which values must be corrected. Furthermore, if the pulsating load torque waveform differs depending on the operating state, it goes without saying that a different current pattern or voltage pattern must be used for each operating state. Furthermore, the current reference generation circuit 11 of FIG. In the voltage reference generation circuit 12 of FIG. 11, the rotation angle information is obtained from the rotation angle calculation circuit 6, but the rotation angle information may be obtained from the rotation angle directly detected using a rotation detector. Further, in the embodiments shown in FIGS. 1 and 11, a hermetic compressor with a built-in brushless motor is used, but a hermetic compressor with a built-in induction motor may be used.

【Effect of the invention】

As described above, according to the present invention, a voltage reference signal or a current reference signal that changes the generated torque of the compressor according to the pulsating load torque is generated according to a preset pattern according to rotation angle information. Because it is configured as follows, it is possible to suppress the vibration of the compressor due to pulsating load torque, and
This has the effect of making the device cheaper.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a control device for a hermetic compressor according to an embodiment of the first invention, FIG. 2 is an equivalent circuit diagram of a brushless motor, FIG. 3 is a block diagram of a brushless motor, and FIG.
The figure is a circuit diagram showing an example of the current control circuit included in the embodiment of Figure 1, Figure 5 is a correspondence diagram of input/output data, Figure 6 is a diagram of the principle of signal conversion, and Figure 7 is the same as Figure 1. FIG. 8 is a circuit diagram showing an example of the average speed calculation circuit included in the current reference generation circuit of FIG. 7. FIG. 9 is a torque waveform diagram. FIG. 10 is a circuit diagram showing an example of a current pattern generation circuit included in the current reference generation circuit of FIG. 7, FIG. 11 is a block diagram of a control device for a hermetic compressor according to an embodiment of the second invention, and FIG. is a circuit diagram showing an example of the voltage reference generation circuit included in FIG.
Figure 3 is a circuit diagram showing an example of a voltage pattern generation circuit included in the voltage reference generation circuit of Figure 12, Figure 14 is a block diagram of a conventional hermetic compressor control device, and Figure 15 is a variable frequency power conversion circuit. A circuit diagram showing an example of the circuit, Fig. 16 is a principle diagram of ON/OFF-ON generation using terminal voltage, Fig. 1
FIG. 7 is a flowchart of repetitive control. 1 is a brushless motor, 2 is a transistor inverter (
(variable frequency power converter), 3 is a current power supply circuit, 4 is a voltage detector, 5 is a current detector, 6 is a rotation angle calculation circuit, 8 is a speed reference generation circuit, 10 is a current control circuit, 11 is a current reference generation 12 is a voltage reference generation circuit. Note that the same reference numerals in the figures indicate the same or equivalent parts. Figure 5 Figure 6 Figure 9 Figure 10 Figure 17

Claims (2)

[Claims] (1) A variable frequency power converter for driving the hermetic compressor at a variable frequency, a current detector for detecting the current of the hermetic compressor, and a current that is applied during one rotation of the hermetic compressor. A current reference generation circuit that inputs rotation angle information of the hermetic compressor and generates a current reference signal that changes the generated torque of the hermetic compressor according to a periodic load torque according to a preset pattern. and a current control circuit that receives the current reference signal and the current signal output from the current detector and outputs a control signal to the variable frequency power converter. Machine control device. (2) A variable frequency power converter for driving a hermetic compressor at a variable frequency; a voltage reference generation circuit that inputs rotation angle information of the hermetic compressor and generates a voltage reference signal that varies according to a preset pattern; and a voltage reference generation circuit that inputs the voltage reference signal and outputs the voltage reference signal to the variable frequency power converter. 1. A control device for a hermetic compressor, comprising: a signal conversion circuit that generates a control signal.