JPH07190463A - Compressor rotation speed control method of air conditioner - Google Patents

Abstract

PURPOSE:To control the rotation speed of a variable speed type compressor to continuous rotation speeds while the rotation speeds are designated stepwise, and reduce offensive noise and vibrations. CONSTITUTION:To obtain an intermediate rotation speed between a stepwise rotation speeds (a) and (b), a compressor is rotated (na) revolutions at a rotation speed (a), and then (nb) revolutions at a rotation speed (b), that is, it is rotated N=(na+nb) revolutions in total, and controls are carried out so that the mean rotation speed between the two rotation speeds becomes the desired rotation speed. In addition, controls are carried out while the value N is not kept constant but changed with the value of (na)/(na+nb)kept constant, so that offensive noise and vibrations are prevented from being produced periodically.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor rotation speed control method for an air conditioner.

[0002]

2. Description of the Related Art In recent years, air conditioners have been widely used in homes, but in order to create a comfortable environment, it is necessary to control the rotation speed of the compressor in fine steps.

A conventional method for controlling the compression rotation speed of an air conditioner will be described below with reference to the drawings. FIG. 1 is a block diagram showing a compressor and its control device. In the figure, 1 is a compressor, and 2 is a compressor controller for controlling the operation of the compressor. In the figure, the compressor control device 2 judges the load required for the air conditioner 1 by a microcomputer or the like, and selects the optimum compressor rotation speed for that load in 60 Hz, 61 Hz, ... To do. Next, a signal for driving the compressor at the rotation speed, for example, a signal such as a pulse width modulation signal (hereinafter referred to as a PWM signal) is generated by calculation, and power is supplied to the compressor 1 by the waveform of this drive signal. The compressor is operated at the selected rotation speed by supplying. With this compressor rotation speed control method, the compressor rotation speed for obtaining a predetermined capacity was controlled in steps of 1 Hz.

[0004]

In such a conventional compressor rotation speed control method, in the compressor control device 2,
The microcomputer is 61Hz up one step of 60Hz,
In addition, the rotation speed is 1
It is not possible to say that the optimum rotation speed for the load can always be selected because it is possible to give instructions only in steps in Hz units and continuous fine adjustment is not possible. To solve this problem, 6
If the rotational speed can be controlled to a fractional part such as 1.25 Hz, the calculation for generating the drive signal becomes complicated, and the number of significant digits of data increases to increase the number of data in the microcomputer. The problem arises that the number and the amount of programming increase significantly.

The present invention solves the above problems, and an object of the present invention is to provide a compressor rotation speed control method capable of finely controlling the rotation speed of a compressor to an optimum speed without increasing the data amount and the program amount. .

[0006]

In order to achieve the above-mentioned object, the present invention provides a compressor of variable rotation speed, and a compressor control device for instructing and controlling the rotation speed of the compressor in a stepwise manner. In the air conditioner equipped with, when the compressor control device indicates a rotation speed c between the stepwise rotation speed a and the stepwise rotation speed b, the compressor control device rotates during N rotations. After rotating the compressor na at the speed a, the rotation speed b
The compressor is rotated by nb at n, and the average rotation speed in N rotations is set to the specified rotation speed c at the rotation speed na and the rotation speed nb such that N = (na + nb), and na / (na + nb) (4) is a constant value, the rotational speed N is changed to control the rotational speed, thereby controlling the rotational speed of the compressor of the air conditioner.

[0007]

According to the present invention, in the above structure, when the compressor control device designates an intermediate rotation speed between the stepwise rotation speeds a and b, the rotation of the rotation speed a and the rotation of the rotation speed b are respectively performed. It is specified that the driving is performed by alternately switching for every predetermined number of rotations na and nb, so that the average rotation speed becomes the specified rotation speed, and at the same time, na / (na + n
Control is performed by changing the rotation speed N = (na + nb) while maintaining the value of b).

[0008]

【Example】

(Embodiment 1) An embodiment of a method for controlling a compressor rotation speed of an air conditioner of the present invention will be described below with reference to the drawings. The configuration of this embodiment is the same as that of FIG. The present embodiment is different from the conventional example in the rotation speed control method of the compressor control device 2. FIG. 2 is a characteristic diagram showing a change state of the rotation speed of the compressor and a change state of the input power in this embodiment. In FIG. 2 (a), the compressor rotates na at the rotation speed a and then rotates nb at the rotation speed b to make the total N1.
It rotates, and at the next rotation speed a, it rotates na 'and the rotation speed b.
Therefore, nb 'rotations have been made, and a total of N2 rotations have been made. Now, the two rotation speeds a and b are a ≈
b, and when the average rotational speeds c1 and c2 are calculated using this relationship, it is approximately obtained as c1 = b + (ab) na / N1 c2 = b + (ab) na '/ N2 To be However, N1 = na + nb, N2 = na '+
It is nb '. Here, if na / N1 = na '/ N2, then c1 = c2. That is, of the number of rotations N, at the rotation speed a, na
In the operation of rotating and then rotating nb at the rotation speed b,
It can be seen that if the value of na / (na + nb) is maintained at a constant value for obtaining the predetermined average rotation speed c, the average rotation speed does not change even if the value of N is arbitrarily changed. The same applies to the next N3 rotation in the figure.

Further, FIG. 2 (b) shows a change in electric power input to the compressor in this case. In the figure, assuming that the input power at the rotation speed a is W2 and the input power at the rotation speed b is W1, the average power W in the section of the number of rotations N1
Is approximately W = W1 + (W2-W1) na / N, where N = na + nb is obtained, and the input electric power also corresponds so that the value of na / (na + nb) corresponds to the predetermined rotation speed c. I understand.

As described above, the value of na / (na + nb) is set so as to obtain a desired rotation speed, and the stepwise rotation speed is switched to set the value between the stepwise speeds a and b. Any rotation speed can be realized on average.

Further, while keeping the value of na / (na + nb) at a predetermined value, the total number of rotations N is controlled not by being changed but by a constant value, so that annoying noise or unpleasant noise of a specific frequency corresponding to the rotation speed is obtained. Vibrations can be prevented from occurring and continuing with regular repetition.

As described above, according to the rotation speed control method for the air conditioner of this embodiment, the stepwise rotation is controlled by switching the two stepwise rotation speeds for each predetermined number of rotations. It is possible to obtain an arbitrary rotation speed in the middle of the speed, and by controlling the total number of rotations by changing the total value of the number of rotations while keeping the ratio of each number of rotations to a predetermined value, annoying noise of a specific frequency. It is also possible to prevent the generation of unpleasant vibration.

[0013]

As is apparent from the above description, the present invention includes a compressor of variable rotation speed, and a compressor control device for controlling the rotation speed of the compressor stepwise. In the air conditioner, when the compressor control device indicates the rotation speed c between the stepwise rotation speed a and the stepwise rotation speed b, the rotation speed a during N rotations of the compressor.
To rotate the compressor na, and then to rotate the compressor at rotation speed b.
The rotation number is set such that the average rotation speed in N rotations becomes the designated rotation speed c at the rotation number na and the rotation number nb where N = (na + nb).
By using the compressor rotation speed control method of the air conditioner in which the rotation speed is controlled by changing the rotation speed N while keeping the value of a / (na + nb) constant, It is possible to realize a continuous rotation speed while designating, and it is possible to prevent the generation of annoying noise or unpleasant vibration of a specific frequency.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts showing a configuration of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing changes in the rotation speed and input power of the compressor in the air conditioner of one embodiment of the present invention, corresponding to the number of rotations at which the rotation speed is switched.

[Explanation of symbols]

 1 Variable speed compressor 2 Compressor control device

Claims (1)

[Claims] 1. An air conditioner comprising: a variable rotation speed compressor; and a compressor control device for instructing and controlling a rotation speed of the compressor in a stepwise manner. When instructing the rotation speed c between the normal rotation speed a and the stepwise rotation speed b, the compressor is rotated at the rotation speed a while the compressor is rotating N times, and then the rotation speed b is set.
The compressor is rotated by nb at n, and the average rotation speed in N rotations is set to the specified rotation speed c at the rotation speed na and the rotation speed nb such that N = (na + nb), and na / (na + nb) ) The method for controlling the compressor rotation speed of the air conditioner, wherein the rotation speed is controlled by changing the rotation speed N while keeping the value of (4) constant.