JPH0823693A - Load allocation control circuit - Google Patents

Abstract

PURPOSE:To equally control torque current command value by achieving a drooping function for an electric motor drive device at each slave side and at the same time adding and subtracting the torque current command signal at a master side at the input stage of a speed operation part as the compensation of the speed command. CONSTITUTION:At each slave side, a drooping signal generator 10 and an adder/ subtractor 11S are laid out at a speed operation part and the speed characteristics of an electric motor 2S at each slave side are subjected to torque drooping or current drooping and follow the speed of a master at an equal speed. Further, the torque current command value of the speed operation result at the master side is given to adder/subtractor 91S and 92S at each slave side from a torque signal command equipment 8 and the output of the torque current command equipment 8 is added to or subtracted from the output of a speed setting equipment 4 at each slave side and then the result is given to the speed operation part, thus driving the electric motor with a drooping function and hence performing stable and proper load allocation control with a constantly uniform load rate. As a result, the torque current command value of each slave can be uniformly subjected to load allocation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor drive device for driving a single load of a connecting material or a connecting material driven by a plurality of electric motors, and more particularly to a load for distributing the load of the plural electric motors. The present invention relates to a distribution control circuit.

[0002]

2. Description of the Related Art In a device in which a load connected by a machine or material or a load of a communicating material (hereinafter referred to as a single load) is driven by a plurality of electric motors, one is positioned as a master and the other is positioned as a slave. It is common practice to have a slave follow a master.

It is also known that the load distribution control is generally performed using the following method. (1) A torque (current) command value on the master side is distributed to each slave side, and this value is used as a torque current command to each slave. (2) A torque (current) command value on the master side is controlled as a torque current limiter value for each slave. (3) Obtain the sum of the torque (current) command value on the master side and the torque (current) command value on each slave side, and then find the ratio to the rated torque (current), and use this value to command the speed to each slave. The correction value of.

[0004]

However, in the prior art of this kind, in the above-mentioned (1), since only the torque current command value is distributed to each slave side, a single load is used. If the load cannot be shared due to the breakage of the load material, etc., the constant velocity relationship between the master and slave will collapse. Further, in the above item (2), variations occur in the respective characteristics in a light load state until the limiter is applied. Furthermore, the above item (3) has a point that it cannot be adopted in terms of compatibility or application because it is an advanced type such as high-speed arithmetic processing because it is redistributed after obtaining the sum and the ratio with the rating. .

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned points, in which each slave-side electric motor driving device has a drooping function and an input stage of its speed calculation section. The torque current command signal on the master side is added and subtracted as a correction of the speed command.

[0006]

With this solution, it is possible to increase / decrease the speed command of each slave side as the master side torque current command value increases / decreases. As a result, the torque current command value of each slave side can be increased / decreased directly. . In this way, the torque current command value between the master and each slave can be controlled to be controlled equally. Therefore, it is clear that the above-mentioned problems (1) and (2) of the conventional technique can be solved and a more complicated calculation method can be eliminated. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a main structure of an embodiment of the present invention. 1M and 1S are actuators for driving electric motors 2M and 2S, and 3M and 3S are speeds that give speed detection signals of the electric motors 2M and 2S. Detector 4 is a speed setter which gives a common speed command, 5M, 5S, 91S, 92S and 11S are adders / subtractors,
6M and 6S are speed controllers, 7M and 7S are torque current controllers, 8 is a torque current command device, and 10S is a drooping signal generator. Here, M represents the master side and S represents the slave side.

That is, in FIG. 1, the common speed command of the speed setter 1 is given to the master and each slave, the outputs of the speed detectors 3M and 3S are fed back to the adder / subtractors 5M and 5S, and the speed controllers 6M and 6S. Along with this, speed calculation is performed. The output of the speed controller 6M, 6S is transmitted via the torque current controller 7M, 7S to the actuator 1M,
1S, and the speed control of the electric motors 2M and 2S is performed by the actuators 1M and 1S, respectively.

Here, on each slave side, a drooping signal generator 10S and an adder / subtractor 11S are arranged in the speed calculator as shown in the figure, and therefore, the speed characteristic of the electric motor 2S on each slave side is torque drooping or torque drooping. The current droop can be achieved and the uniform speed can be followed to the master. Further, the torque current command value of the speed calculation result on the master side is given to the adder / subtractors 91S, 92S on each slave side by the torque current command device 8. As a result, on the slave side, the output of the speed setter 4 and the output of the torque current commander 8 are added / subtracted by the adder / subtractor 91S, 92S, and the result is given to the speed calculator to drive the motor having the drooping function. Will be things. Therefore, such a master side,
When driving a plurality of motors on each slave side, load distribution is controlled stably and satisfactorily with a uniform load factor.

[0010]

As described above, according to the present invention, it is possible to provide a device having a simple configuration in which the torque current command values of the slaves that follow the speed of the master are uniformly distributed.

[Brief description of drawings]

FIG. 1 is a system diagram showing a main part configuration of an embodiment of the present invention.

[Explanation of symbols]

 1M actuator 1S actuator 2M electric motor 2S electric motor 3M speed detector 3S speed detector 4 speed setter 5M adder-subtractor 5S adder-subtractor 6M speed controller 6S speed controller 7M torque current controller 7S torque current controller 8 torque current commander 91S Adder / subtractor 92S Adder / subtractor 10S Drooping signal generator 11S Adder / subtractor

Claims (1)

[Claims] 1. In a system in which a single load is driven by a plurality of electric motors that cause one master to follow another slave, the speed calculator of each slave has a drooping function and the speed of each slave. A load distribution control circuit characterized in that a calculation unit is configured to add and subtract a master torque current command signal as a correction of a speed command.