JPS60257790A - Controller of ac elevator - Google Patents

Abstract

PURPOSE:To remarkably reduce the noise of a motor by controlling the pattern of a magnetic flux and a slip constantly or variably in response to a load. CONSTITUTION:A magnetic flux command phi2* is outputted from a magnetic flux pattern generator 8, a torque current command i* is outputted from a torque current pattern generator 9, and a slip frequency command omegaS* is outputted from a slip frequency pattern generaotr 10 in response to a torque command T* by the control of a speed regulator 7 to control a motor 4. The generator 8 sets a magnetic flux to the prescribed value lower than at rated time when a load is the prescribed value or lower and variably to the load when the load is the prescribed value or higher, the generator 8 sets the slip variably in response to the load when the load is the prescribed value or lower and to the constant value when the prescribed value or higher. Thus, the noise of the motor can be reduce without losing the adaptability of a control system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a control device for an AC elevator operated by an inverter or a cycloconverter.

[Conventional technology]

Methods of speed control by supplying variable voltage, variable frequency AC power to an induction motor (hereinafter referred to as a motor) include a method of operating with a constant secondary magnetic flux linkage (hereinafter referred to as a magnetic flux) and a method of operating with a constant secondary flux linkage (hereinafter referred to as a magnetic flux). There are methods to operate with constant magnetic flux and variable, or methods to operate at maximum efficiency slip frequency.

[Intermediate point that the invention attempts to solve]

The generation of magnetic flux requires a motor secondary time constant (0,005S to 0.
Since there is a delay time determined by +s), there is a delay time in the generation of torque due to this, and therefore, in fields where coordination is required, the magnetic flux is operated at a constant value. In elevator speed control as well, it is desirable to operate with constant magnetic flux from the viewpoint of coordination. In this case, it is necessary to generate a corresponding torque for all loads, so it is necessary to set the magnetic flux to a large value, and usually the rated magnetic flux of the motor (the rated load of the motor, the rated voltage of Magnetic flux when operating at rated current).

On the other hand, since elevators are required to operate extremely quietly, it is necessary to minimize motor electromagnetic noise, which is one of the loudest sounds when an elevator is running. This motor electromagnetic noise has a strong relationship with the magnetic flux of the motor, and increases significantly as the motor magnetic flux increases.

Therefore, if the magnetic flux is set to the rated magnetic flux and operated at a constant value, a large electromagnetic noise will be generated across all loads, and this is not practical as a driving method for an electric heater.

In order to avoid this problem, is there a way to control the torque by keeping the shear constant with respect to the load and varying the motor magnetic flux? In this case, there is no slippage when moving from the drive region to the braking region G or vice versa. You need to reverse the polarity of
At this time, the elevator generates significantly large car vibrations.

This is because while the slip frequency suddenly changes from a constant value of positive polarity to a constant value of negative polarity, the change in magnetic flux is always delayed, and this delay amount is ``2'' in the vicinity where the polarity of the edge frequency changes. This is because the amount of change in the magnetic flux command is large, so it becomes larger.

Therefore, an operation method that maintains a constant slip is problematic from the viewpoint of elevator ride comfort.

Additionally, as a method of operating with variable magnetic flux and variable slip frequency, there is also a method of operating at the maximum efficiency slip frequency for all loads, but the pattern settings for the slip frequency and magnetic flux are extremely complicated, and these pattern settings are also difficult. This has the problem of having to be changed every time the motor specifications (motor capacity, voltage specifications, etc.) change, which makes it impractical for elevators.

[Means for solving the problem and Oζ action] In order to solve the above problems, the present invention aims to reduce the load to a constant value lower than the rated value when the load is below a predetermined value, and to reduce the load to a constant value lower than the rated value when the load is equal to or higher than the predetermined value. Means for setting the magnetic flux so that it is variable according to ) and a means for setting the magnetic flux.
The pattern is set so that the linearity of the control system is maintained. As a result, when the load is light, the magnetic flux is kept at a constant value lower than the rated value, and the flux is proportional to the torque command, and when the load is heavy, the flux is constant and the flux is proportional to the torque command. Since the motor is operated in a variable manner, it is possible to reduce motor noise without impairing the coordination of the control system.

〔Example〕

FIG. 1 is an overall configuration diagram showing one embodiment of an AC electric heater control device according to the present invention. Here, an example in which the present invention is applied to vector control is shown.

In the figure, R, S, and T are positive-phase AC power supplies, 1 is a converter device that converts positive-phase AC power into DC, 2 is a filter that smoothes the output of converter device 1, and 6 is a DC variable variable Ichikawa variable. Inverter device for converting frequency into alternating current, 4-
The motor that moves the elevator, 5 is the rotation speed of motor 4 (
6 is a speed command generator that generates a predetermined speed command N, and 7 amplifies the deviation between the speed command N and the speed feedback signal line 1. The speed regulator 8 outputs a predetermined magnetic flux command φ according to the torque command T*.
Magnetic flux Bakun generator outputs 2, 9 is l-lux command T
10 is a shear frequency pattern generator 111 that outputs a predetermined shear frequency command ωS* in response to the torque command T*. 12 is a phase advance circuit that converts the magnetic flux command φ2* into an excitation current command 1□I, and 12 is an excitation current command unit 1. A vector calculator that calculates the primary current command 11 from A* and the torque current command 9T', 13 is a relationship for calculating the phase difference θ between the primary current hector f1 and the magnetic flux - torque current J and φ2 14 is a differentiator (θ□' is the primary frequency command.

In the configuration described above, since vector control is well known, a detailed explanation will be omitted.Is it the deviation between the speed command N of one electric wave and the speed return signal Nr from the speed generator 5, or the speed adjustment tVl;? It is amplified by r7 and output as a torque command T*. In response to this torque command T*, a predetermined speed command φ2*, torque current command IT*1 and slip frequency command ωS* are output. Based on the relational expressions (1) to (4) below, each command φ2*+ lT*l ωS*
Meanwhile, the primary current command 11* and the primary layer wave number command ω1* are calculated, and the magnetic flux φ2 and the slip angular frequency ωS are controlled to have a predetermined pattern.

φ””' 1+T, SIM ”” fl)□, -F evaluation〒7...(2) dθ θノ1+ωStenωr+□・-・(3) d, t −θ−ωs T 2 ・・・・・・・・・・ (4) Second
The figure shows the pattern of each command in the present invention.
(a) shows the pattern of the magnetic flux command φ2*, (O) shows the pattern of the slip frequency command (++3*, and -(C) shows the pattern of the torque current command -7*.As is clear from Fig. 2, When the magnetic flux command φ2* is less than the absolute value of the torque command T* or a predetermined value (To), that is, when the required torque for elevator is less than the predetermined value, the magnetic flux command φ2* is set to a constant value lower than the rated magnetic flux, and the torque command T If the required torque of the elevator is greater than the specified value,
It is made to be proportional to the square root of the torque command T*. The slip frequency command o)s* is proportional to the torque command T* when the absolute value of the torque command T* is less than or equal to a predetermined value, and becomes a constant value when the absolute value of the torque command T* is greater than or equal to the predetermined value.

Here, the reason why the magnetic flux command φ2* and the slip frequency command ωS* have the characteristics shown in FIG. 2 with respect to the torque command T* is as follows.

That is, the torque Te generated by the motor is Toαφ1. , I, 5100. (5) is given by. Therefore, by setting the pattern of ωS* so that when the magnetic flux φ2 is constant, the relationship between ωS* and T* becomes ωS*αT*, and when (IJ S is constant, the relationship between φ* and T* By adding the pattern of φ so that φ*αr − is below, the generated torque TO of the motor is always TeαT with respect to the torque command ゛]”*
* becomes.

As a result, the linearity of the control system is maintained, ensuring good speed control.

In addition, the pattern of l·lux current command unit 7,' is shown in Figure 2 (
It becomes as shown in c), which means that Te− has φ2〕 (
Since K is a constant)---[6), in order to maintain the linearity of the control system, it is necessary to determine the pattern of φ2*. That is, as mentioned above, in order for the control system to be linear, TeαT*, and therefore from equation (6), T*α
It is necessary that φ2*IT*. Here, φ2 is IT”l > ITOI φ2*αFTIT l <
Since φ2- is constant at 1Tol, the pattern of T is: +T*l > ITol, IT*, r-* * ITl < 1Tol, -, T αT, as shown in Figure 2(c). become.

FIG. 6 is a diagram showing an embodiment of the configuration of a magnetic flux pattern generator according to the present invention. The magnetic flux pattern generator 8 is composed of an absolute value circuit 8as, a square root calculator 3b, and a lower limit value limiting circuit 8C, and can obtain a pattern of magnetic flux command φ2* (not shown in FIG. 2) from torque commands T and T.

FIG. 4 is a diagram showing an embodiment of the configuration of a torque current pattern generator according to the present invention. The l·lux current pattern generating JE device 9 has an infinite value circuit 9a.

It is composed of a square root calculator 9b, a minimum value selection circuit 9cs, a polarity discrimination circuit 9a', and a polarity switching circuit 9e, thereby making it possible to obtain the pattern of the torque current command IT* (shown in FIG. 2).

Furthermore, the pattern of the slip frequency command ωS* shown in FIG. 2 can be easily obtained by configuring the slip frequency pattern generator with an upper limit value and lower limit value limiting circuit.

4r. In the above explanation, the patterns of each command have been shown with ideal characteristics, or they can be simplified to the extent that they do not interfere with air control.

FIG. 5 shows a simplified example of the pattern of the magnetic flux command φ2*, in which lT*l and -41Tol are linearly raised as φ2*αT*. Even in this case, almost the same responsiveness as described above can be obtained.

Figure 6 shows the simplified magnetic flux command φ2*limiting circuit 8 in Figure 5.
It is possible to have a simple configuration with only c.

〔Effect of the invention〕

According to the present invention, the magnetic flux and slip frequency of the motor are always controlled according to the pattern shown in Fig. 2 with respect to the required torque, and the magnetic flux is sufficiently reduced during operation of one dog section compared to constant rated magnetic flux operation. Motor noise can be significantly reduced, and by linearizing the control system, good speed response can be obtained.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram showing one embodiment of an AC elevator control device according to the present invention, FIG. 2(a) is a diagram showing a pattern of magnetic flux command according to the present invention, and FIG. FIG. 2(C) is a diagram showing the pattern of the shear frequency command, FIG. 2(C) is a diagram showing the pattern of the torque current command of the present invention, and FIG. Fig. 4 shows IK showing one embodiment of the configuration of the l/rk current pattern generator according to the present invention, Fig. 5 shows another embodiment of the magnetic flux command pattern, and Fig. 6 shows magnetic flux pattern generation. It is a figure which shows another Example of a container. 1. Converter device... Inverter device 4... Motor 5... Speed generator 6... Speed command generator 7... Speed regulator 8... Magnetic flux pattern generator 9...・Torque current pattern generator 10, , Slip frequency Bakun generation monitor 1 inch * Speed command T * ... Torque command φ2 * ... Magnetic flux command] T * ... Torque current command IV4 * ... Excitation current Command unit 1*...Primary current command ωS7...Slip frequency command 0/1*...Primary frequency command Special communication/Applicant: Fujichik Co., Ltd. No. 1 Kugyu Z Figure Freezing index ψf No. 3 Figure 4

Claims (1)

[Claims] A converter converts commercial AC power into DC power, an inverter converts it into variable frequency AC power, and the converted AC power drives an induction motor to operate an elevator.1. means for setting the magnetic flux to a constant value lower than the rated value when the required torque is less than a predetermined value; An AC electronic device characterized in that it is provided with a means for setting the torque so that it is variable according to the required torque when it is below a predetermined value, and is not set to a constant value when the required torque is above a predetermined value. Evening control device.