JPH01222677A - Torque control type rotary motor-driven machine - Google Patents

Abstract

PURPOSE:To eliminate a shaking torque and to effectively and rapidly reduce a vibration by calculating a control amount on the basis of rotary speed information at respective rotating angles during one revolution of a rotary main shaft, and correcting to lead the phase of obtained control amount before 90 degrees from the same rotary angle after one revolution CONSTITUTION:A detection signal 24 obtained from a gap sensor 23 is converted by a waveform shaping circuit 29 to a rotary pulse signal 25, and supplied through an interface 30 to a microcomputer 31. The microcomputer 31 obtains the pulse interval of the signal 25, thereby calculating a rotating speed. Then it supplies a current command responsive to a deviation between the rotating speed and a command speed to an inverter 36. On the other hand, a current command obtained at this time is output as that at the time of (360-90) degrees phase-corrected at 90 degrees from the same angle after one revolution delayed at 360 degrees.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to rotating machines in general in which load elements are driven by electric elements, and in particular to rotary machines in which a load element is driven by an electric element, and in particular, when the load (absorbed) torque fluctuates with a certain period, The present invention relates to a silk type rotating machine suitable for reducing vibrations of a rotating machine by suppressing rotational speed fluctuations.

[Conventional technology]

``Electric element [Thus, a hermetic compressor will be explained as an example of a rotating machine that is driven once. 10 and 11 show the conventional structure of a rotary compressor. In these figures, reference numeral 1 is a container that houses an electric element and a compression element therein. Reference numeral 2 denotes a stator fixed to the container 1, and is fixed to the inner circumference of the container 1. A rotor 3 that is fitted onto the main shaft 4 and rotates together with the main shaft 4 is disposed inside the stator 2 . The main shaft 4 is supported by a main bearing 5 and a partial bearing 6. And these bearings 5,
6 is fastened to the cylinder block 7. The cylinder block 7 is fixed to the container, and a compression chamber 12 is formed within the cylinder block 7. Inside this compression chamber 12 is a roller 8 which is eccentrically integrated with the main shaft 4.
A vane 9 is provided which is urged against the surface of the roller 8 by a spring 10. With this configuration, when the main shaft 4 rotates, refrigerant gas is sucked in from the suction accumulator 11 provided outside the container 1, is pressurized to a predetermined pressure by the compression chamber 12, and is released into the case along the direction of the arrow. It is discharged outside.

A compressor having the above-mentioned structure is disclosed, for example, in Japanese Patent Application Laid-Open No. 58-18
It is disclosed in Japanese Patent No. 7635.

[Problem to be solved by the invention]

By the way, the gas absorption torque within the compression element fluctuates greatly during one rotation of the main shaft 4, and due to the difference in electromagnetic l-lux between this and the electric element, that is, the residual torque, the rotating system including the main shaft 4 has a rotational speed. A problem arises in that rotational direction vibration is induced on the fixed side consisting of the container 1 and the vibration-proof support member 13.

FIG. 12 schematically shows, as an example, the causes of vibration in a rotary compressor. For the rotating system (rotor 14.15 and main shaft 16) and the fixed system (stator 17.18 and container 19) of each of the compression element and electric element, the gas compression torque Tc and the electromagnetic torque TM are as shown in the figure, respectively. It works as shown below. In addition, in the figure, clockwise direction is shown as positive, and counterclockwise direction is shown as negative.

The equations of motion of the rotating system and fixed system at this time are and the inertia torque of the rotating system and fixed system, respectively, and Ta
-Ts corresponds to the residual torque (excitation torque) ΔTrk,
K is the spring constant of the compressor support spring, φRL, times dφ
R is the rotation angle, and there is a relationship of rotational angular velocity ωR=t of the rotating system.

Therefore, by detecting the rotational speed ωR of the rotating system and making it zero in time, TH-Tc=O, and the motor torque TM and load torque Tc being balanced, (2) Shikishikoo (Suru-4
= Excitation torque is eliminated, and vibration in the chamber rotation direction, which is the cause of vibration and noise in rotating machinery, can be suppressed.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 62-83530, the load torque Tc of the compressor fluctuates greatly during one rotation, but it is a periodic pulsating load that is repeated over one rotation, so we focused on a certain rotation angle. However, the load torque value does not change much. Therefore, reliable torque control with high control stability is possible by outputting the rotation speed detected at each rotation angle at the same angle after one rotation.

However, the rotational speed variation curve and the load torque T6 variation curve generally have different phases. FIG. 13 shows both a load torque curve and a rotor rotational speed fluctuation curve in a rotary compressor. As shown in the figure, the rotational speed variation is in a delayed phase with respect to the torque variation.

Therefore, in a torque control machine that detects the rotational speed of the rotor and increases the motor output when the detected speed is smaller than the commanded speed, and decreases the motor output when the detected speed is greater than the commanded speed, this phase lag is Therefore, there is a problem in that it is not possible to completely synchronize one herk of motor output with the load torque, and some kind of phase correction means is required.

Here, as shown in Fig. 14, the torque component of the rotary compressor includes, in addition to the rotation-fire component corresponding to the operating frequency of the compressor, second-order, third-order, etc. harmonic components. have a certain phase difference with each other. Referring to equation (1), the rotational speed ωR has an integral relationship with respect to the excitation i to the torque ΔTr.

Here, it is assumed that the excitation torque ΔTr is composed of periodic fluctuation components up to the nth-order rotational component as follows. However, ω. is the average speed, γR is the phase difference of the R-order component, △TrR
is the amplitude of the R-order component.

Substituting equation (3) into equation (1) and integrating, =□ Σ
−5in(Rω.1−−+γR)+ω.

JR・ω. R=I R2R (4) is obtained. As can be seen from equation (4), the speed fluctuation component of the rotation R-order component is -
The phase is delayed. In reality, the rotor rotational speed of R is a combination of up to the n-th order components, and the ratio of these components also varies depending on the operating conditions, and the phase delay angle also varies each time.

However, as shown in FIG. 15, the fluctuation amplitude is largest in the one-rotation component, and the magnitude of the higher-order components rapidly attenuates. Furthermore, for the rotational first-order and n-order components, even if the torque amplitude is the same, the speed amplitude will be i/R.

Therefore, in a system where the number of speed detection pulses per revolution is relatively small and there is no need to consider the influence of harmonic components,
By focusing only on the ignition component and correcting its phase delay by 90 degrees during one rotation, it is possible to make the rotational speed fluctuation phase almost coincide with the torque fluctuation phase.

The present invention was made in view of the nature of the above-mentioned problems, and its purpose is to detect the rotational speed at each rotational angle of the rotor caused by load torque fluctuation, and to make the rotational speed at each rotational angle equal to the commanded speed. By calculating the necessary electromagnetic torque control amount of the electric element so that The object of the present invention is to provide a torque-controlled rotary electric machine that can reliably and quickly reduce vibration.

[Means to solve the problem]

To achieve the above object, the present invention provides a torque-controlled rotary electric machine including an electric element, a load element connected to the electric element via a rotating main shaft and driven by the electric element, and a load element that is driven by the electric element. A torque control type rotary electric machine comprising: a torque control device that controls the electromagnetic torque of the electric element so that the difference (residual torque) between the electromagnetic torque and the load (absorption) torque generated by the load element is zero. The torque control device controls the electromagnetic torque of the electric element based on rotation speed information at each rotation angle during one rotation of the rotating main shaft, and adjusts the output position by 90 degrees from the same rotation angle after one rotation.
This is a configuration in which the phase lead is corrected toward the front.

In addition, the present invention divides one rotation of the rotating main shaft into n equal parts.
Generate a position detection pulse for each division angle, detect the rotation speed in each division section from the pulse interval, feed it back, find each deviation speed between this and the command rotation speed, and calculate the speed required to minimize this deviation. Calculate the electromagnetic torque output amount,
The torque control device outputs the obtained control amount a number of detected pulses corresponding to 90' from each of the same divided angle sections of the next revolution of the rotating main shaft, It is preferable that the 90° phase correction is not performed when the 90° phase correction occurs.

[Effect]

With this configuration, the control amount required to bring the excitation torque to O can be calculated by detecting each rotational angle position during one rotation of the rotating main shaft and using the rotational speed corrected by advancing 90' from that position. However, since the electromagnetic torque of the electric element can be outputted in synchronization with the fluctuation of one herk of the load at each rotation angle, the residual torque can be reliably and quickly reduced.

Furthermore, regarding phase correction, if the 90° phase correction is not performed when the deviation speed approaches O, there is no risk of disturbing the control stability after the system starts torque control and is sufficiently stabilized.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an example in which the present invention is applied to a case where a rotary compressor, which is a type of rotating machine driven by an electric element (DC motor), is driven by an inverter. Here, since the compressor according to this embodiment has almost the same configuration as the conventional compressor shown in FIGS. 11 and 12, only the different parts will be explained, and the same parts will have the same reference numerals. By adding , the explanation will be omitted.

In FIG. 1, the rotor 3 of the electric element 20 and the compression element 2
One end of the rotating main shaft 4, which is directly connected to the rotor 8 of 1, is extended, and a gear 22, which is a rotation detection member, is fixed, so that the gear 22 and the main shaft 4 rotate together. A gap sensor 23 is fixed to the container 1, and a gear 2
2 is detected and a pulse signal corresponding to the rotational speed of the main shaft 4 is output.

FIG. 2 shows a series of processes for determining the rotation speed fluctuation of the rotating main shaft 4 from the pulse signal detected by the gap sensor 23.

Now, when the gear 22 rotates as shown in FIG. 2(a), a sinusoidal detection waveform 24 as shown in FIG. 2(b) appears on the gap sensor 23. This is converted into a pulse train by waveform shaping based on threshold 1-voltage 27, as shown in FIG. 3(c). Measure each pulse width T□, T2...Tn of this pulse time series data, and calculate the rotation speed variable N at each time (28) from its reciprocal N, = 1/T. The same figure (d
).

FIG. 3 shows the overall configuration of the torque control device. That is, the detection signal 24 obtained by the gap sensor 23 is converted into a rotation pulse signal 25 by the waveform shaping circuit 29 and sent to the microcomputer CPU 31 via the interface 30. The microcomputer 38 is activated by the rotation pulse signal 25 and executes a series of detection-calculation-command operations. That is, the rotation pulse interval is clocked by a microcomputer built-in timer to obtain time T1, and the rotation speed Ni is calculated from this.

Then, the electric element 2 of the compressor necessary to make the rotation speed N'' equal to the command speed Nc at each rotation angle during one rotation.
0 is calculated, the above Nj is advanced by 90° phase angle, and is output at the next rotation. This control signal is then sent to the control section, and by the current control operation of the pace driver 35, the inverter 36 continuously controls the compressor rotational speed so that the fluctuation is always within a certain tolerance value. These series of control loops are then written into the ROM 33.

The control flow of this control circuit will be explained in detail with reference to the block diagram shown in FIG. Note that S shown in the figure is a Laplace operator, and - indicates an integral element. Load torque 'r of the compressor with respect to the electromagnetic torque TM of the electric element 20
G acts as a disturbance, and its residual torque T1. l −
T c =△Tr becomes the excitation torque, which varies according to the rotational speed ωR=□·△T”r.

, JR-8 The rotation angle 19R due to this rotation speed ω is sampled by the gear 22, etc., and the time of the pulse is ・1
Measure.

(k) The microcomputer 38 calculates the pulse time tF and (k-1) (
k-], ) (k) Ot-
+,) Interval of pulse time t' ΔTr=tF −
Find tF. Then, the pulse (k) rotational speed NF28 is determined by the method explained in FIG.

(k) On the other hand, the detected speed NF28 is fed back to find the command rotation speed N and which deviation speed △IJ'' (41), and the PI
The current command value (k) is determined by (proportional integral) control so that the deviation Δ(k) becomes zero. Here, as shown in the figure, if the number of detected pulses during one rotation is n, then n integrators are prepared and each integrator (42) is operated by switching for each pulse input. As a result, an integral operation is performed independently for each pulse detection angle.

Then, the phase of the obtained control amount was corrected to 90' from the same angle after one rotation delayed by 360° (360'-90
″) output as a current command value when the time changes.

As shown in FIG. 5, this means includes n deviation speed input switches (47) (corresponding to n pulses per rotation), and when the switching position is R, the integral container output cass inch (48) This can be done by setting the switching position to 90 degrees to the front, 360'', that is, - narrow front (-) = 4.

(Digital scene is D/A converted (D/A conversion constant kn8) multiplied by torque constant kT) The electric element is electromagnetic The torque control system related to the present invention is configured as described above, and according to this control loop Continues to operate at all times.This phase difference 9
0' correction is effective when torque control is not sufficient, but after the system has sufficiently stabilized to start torque control, in other words, when the deviation ΔN=O, conversely, it is necessary to correct the harmonics without a 90a phase lag. By detecting wave fluctuations, there is a risk that incorrect phase correction will be made and control stability will be disturbed.

In such a case, one method is not to perform the 90° phase correction when the deviation speed approaches 0.

FIG. 6 is a diagram showing the effect of phase correction. The vertical axis shows the magnitude of rotational speed fluctuation, and the horizontal axis shows torque control time. As shown in the figure, there is a large difference in convergence between when 90° phase correction is performed and when no phase correction is performed.

FIG. 7 shows the time course of the motor torque output during this torque control. In addition, ■, ■, ■ in Figure 7.

■ indicates the states at times ■, ■, ■, and ■ in FIG. 6, respectively.

As is clear from the figure, it can be seen that the 90° phase correction causes the torque output to grow while always matching the fluctuations in the load torque. On the other hand, it can be seen that when phase correction is not performed, the motor torque output is generated concentrated at the wrong position, and it is difficult to match the phase of the load torque.

The method for controlling torque when operating a hermetic rotary compressor by driving an electric element with an inverter has been described above, but due to the nature of the present invention, the method is not limited to this. This can be an effective means for all rotating machines in which the negative absorption torque periodically fluctuates.

Furthermore, if the concept of the present invention is developed, it can also be used for auxiliary machines (AcG) used in internal combustion engines for automobiles.

That is, as shown in FIG. 8, in an internal combustion engine, gas torque fluctuates due to changes in cylinder pressure due to suction and compression of air-fuel mixture, expansion of combustion gas, etc., and changes in the angle of the connecting rod with respect to the crankshaft. The reaction of this torque fluctuation is then transmitted from the cylinder block to the member supporting the internal combustion engine, causing that member to vibrate. Therefore, in order to reduce this vibration, the load torque can be increased or decreased by increasing or decreasing the power generation amount of the ACG in accordance with fluctuations in the driving torque of the internal combustion engine. Figure 9 is based on this idea.
An example is shown. That is, the microcomputer 56 calculates the rotational speed fluctuation of the crankshaft based on the output of the crank angle sensor 58 built into the distributor 53, and the load control unit 57 adjusts the ACG 55 to keep it constant.
control the amount of power generated. Even in such load torque control, rotation speed feedback at each rotation angle can be used to eliminate the residual torque between the drive torque and the load torque, and it is appropriate to apply the 90° phase correction method of the present invention. It is.

〔Effect of the invention〕

As is clear from the above explanation, the present invention has the following effects.

Using the rotation speed detected at each rotational angle position during one rotation of the rotating main shaft and corrected by advancing 90 degrees from that position,
The control amount required to bring the excitation torque to O can be calculated, and the electromagnetic torque of the electric element can be output in synchronization with the fluctuation of the load torque at each rotation angle, so the residual torque, that is, the excitation torque, can be Can be made smaller reliably and quickly. Therefore, for all rotating machines that are driven by electric elements and have periodic load torque fluctuations, a significant reduction in chamber excitation torque, in other words, a significant reduction in chamber rotational vibration of the entire container, is achieved. , low-speed operation below the resonance point, or significant simplification of the vibration isolation structure can be realized. Furthermore, since the response of the control system can be made faster, the torque control implementation range can be expanded to a higher speed range, and vibration can be reduced over a wider rotational speed range. As a result, it can contribute to downsizing the entire system, saving power through variable speed operation over a wide range, and improving comfort.

Further, regarding phase correction, if the 90° phase correction is not performed when the deviation speed approaches O, there is no risk of disturbing the control stability after the system starts 1-herk control and is sufficiently stabilized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a compressor according to an embodiment of the present invention, FIGS. 2(a) to 2(d) are diagrams showing a series of processes for determining rotational speed fluctuations from detection signals, and FIG. 3 is a diagram showing torque FIG. 4 is a block diagram showing the control flow; FIG. 5 is a diagram explaining 90° phase advance correction between deviation input and integral output; FIGS. 6 and 7 are diagrams showing the overall configuration of the control device. FIGS. 8 and 9 are diagrams each illustrating the effect of 90° phase correction; FIGS. 8 and 9 are diagrams illustrating an example in which the present invention is applied to an automobile ACG;
Fig. 10 is a longitudinal sectional view of a conventional hermetic compressor, Fig. 11 is a sectional view taken along the xl-x1 arrow in Fig. 10, and Fig. 12 is a partial longitudinal sectional view illustrating the residual torque generation mechanism in a rotating machine. 13 is a diagram for explaining torque fluctuations and speed fluctuations during one rotation, and FIG. 14 is a diagram showing the results of rotation modulus ratio analysis of the torque waveform. 4. Rotating main shaft, 20. Electric element, 21... Compression element,
28... Rotation speed fluctuation, 38... Microcomputer, 41 Speed deviation, 42.n pulse integrator, 45... Current command value,
47. Input selector switch, 48... Output selector switch. Agent Patent Attorney Tatsuyuki Unuma Figure 1 1: Container 7 Terminal Flock 2: Stator +3: l'H exhibition support 3: Rourke 20:%f! initial mass 4
:Ro quantity and soil axis 21. Compression 5° main bearing
22゛Tooth Wheel 6 Yukakuji Temple
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2) Omamoto Book 55: AC
G53°D≧1 Node User Fig. 11 Fig. 12 Fig. 13 Main shaft rotation angle θ (rυd) Fig. 14

Claims (1)

[Scope of Claims] 1. An electric element, a load element connected to the electric element via a rotating main shaft and driven by the electric element, and an electromagnetic torque generated by the electric element and a load (absorbed) generated by the load element. ) a torque control device for controlling electromagnetic torque of an electric element so as to make a torque difference (residual torque) zero; A torque control type characterized in that the electromagnetic torque of the electric element is controlled based on the rotation speed information at each rotation angle during one rotation, and the output position is phase-advanced by 90 degrees before the same rotation angle after one rotation. Rotating electric machine. 2. One revolution of the rotating spindle is divided into n equal parts, and a position detection pulse is generated every n division angles. From the pulse interval, the rotation speed in each division section is detected and fed back, and this is combined with the command rotation speed. Determine each deviation speed, calculate the electromagnetic torque output amount required to minimize this deviation amount, and apply the obtained control amount to the detection pulse corresponding to 90° from the same divided angle section of the next rotation of the rotating main shaft. 2. The torque-controlled rotary electric machine according to claim 1, wherein the torque control type rotary electric machine outputs the output by a number of points in front of each other. 3. The torque-controlled rotary electric machine according to claim 1, wherein the torque control device is capable of not performing the 90° phase correction when the deviation speed approaches zero.