KR20090071909A - Method and apparatus for multi motor control, system for multi motor control - Google Patents

Abstract

A method, an apparatus, and a system for controlling a multi motor are provided to minimize a pressure change of a pipe by controlling a driving stop of a main motor or a sub motor when an interlock signal is generated. A PID(Proportional Integral Derivative) controller(111) compares a feedback signal with a reference signal about a pressure value of a pipe, and controls an operation frequency of a main motor according to the compared result. A control part(112) increases a sub motor one by one in case the feedback signal is less than the reference signal. The control part stops the sub motor one by one in case the feedback signal is more than the reference signal. A driving control signal setting part(113) sets a change time and a change frequency of at least one sub motor and the main motor according to a control signal of the control part and a control signal of the PID controller.

Description

Multiple motor control method and apparatus, multiple motor control system {METHOD AND APPARATUS FOR MULTI MOTOR CONTROL, SYSTEM FOR MULTI MOTOR CONTROL}

The present invention relates to a method and apparatus for controlling a plurality of motors and a control system for a plurality of motors, and more particularly, to control a main motor and an auxiliary motor so that a change in pressure in a pipeline is minimized when an abnormality occurs in the main motor or an auxiliary motor. A plurality of motor control method and apparatus and a plurality of motor control system.

In general, in the field of mainly controlling the flow and hydraulic pressure such as a fan or a pump, a single controller adjusts several electric motors to minimize the energy used and reduce the total cost of ownership of the entire system. Many motor control devices (Multi Motor Control Device) that can simultaneously achieve the effect of lowering the cost is used.

An inverter may be used as the control device, and the inverter includes a PID (Proportional Integral Derivative) controller to receive feedback of the control amount of the process and control a PID of one main motor through the PID controller. A control signal is generated to be operated by the commercial power source so that the control amount fed back is kept constant.

In more detail, the inverter operates at least one auxiliary motor when the flow rate or hydraulic pressure is insufficient or cannot be controlled by the main motor alone. When is generated, by controlling the operation sequence of starting or stopping the motor to control to minimize the pressure change in the pipe.

If there are four auxiliary motors, if any one of the auxiliary motors fails and an interlock signal is generated, all auxiliary motors are stopped in the reverse order of operation, that is, FILO (First Input Last Out). Set the operation sequence of the auxiliary motor again and start it. Such a method causes a change in pressure in the pipeline because the auxiliary motors must be stopped and then restarted, and the operation time of the specific auxiliary motor becomes long, causing a problem of frequent replacement. Another method is a method of controlling the flow rate or the hydraulic pressure by temporarily stopping the operation of all the auxiliary motors for a quick return and by pulsing the main motor (maximum operating frequency). Such a method can be quickly returned to the steady state, but since the auxiliary motor is stopped at a moment, the pressure change is so great that it cannot be applied to a large flow rate and hydraulic pressure used in the pipeline.

If an abnormality occurs in the main motor and an interlock signal is generated, the inverter cannot perform PID control. In this case, all motors should be shut down as much as possible, and a flexible auxiliary motor should be replaced by the main motor. When the main motor and the auxiliary motors are all shut down at the same time, the entire system may be severely damaged and damaged. In order not to overload the main and auxiliary motors, the starting and stopping sequence should be set.

Therefore, in order to solve the above problem, the present invention controls the operation stop and start sequence of the main motor and the auxiliary motor so that the pressure change of the pipeline is minimized when the interlock signal is generated by the main motor or the auxiliary motor. A multi-motor control method and apparatus, and a multi-motor control system are provided.

Accordingly, the method for controlling a plurality of motors according to the present invention includes the steps of: operating a main motor, receiving a pressure value of a pipe line, and comparing the feedback signal with a reference signal; Increasing and starting the auxiliary motors one by one in a preset order when the feedback signal is less than the reference signal; And when the interlock signal is generated by any one of the at least one auxiliary motor operated, stop the operation of the auxiliary motor causing the interlock signal, and maximize the operating frequency of the main motor. Adjusting to; made.

And after the operation of the auxiliary motor that causes the interlock signal is stopped, determining whether there is an auxiliary motor corresponding to the next sequence of the stopped auxiliary motor; Determining whether the next auxiliary motor is movable when there is a next auxiliary motor corresponding to a next step as a result of the determination; And operating the next auxiliary motor when the next auxiliary motor is movable, as a result of the determination.

And determining whether there is an auxiliary motor corresponding to the next order when an interlock signal is generated by the auxiliary motor to be operated currently while the auxiliary motors are being operated one by one according to the preset order. Determining whether the next auxiliary motor is movable when there is a next auxiliary motor corresponding to a next step as a result of the determination; And operating the next auxiliary motor when the next auxiliary motor is movable, as a result of the determination.

The method may further include: stopping at least one of the at least one auxiliary motor operated one by one when an abnormality occurs in the operating main motor and generating an interlock signal, and stopping the operation of the main motor; And stopping operation of the at least one auxiliary motor and the main motor, changing and setting any one of the at least one auxiliary motor operable to the main motor after a predetermined time, and starting the changed set main motor. It is characterized by.

In addition, the operation stop of the at least one auxiliary motor that is operated is characterized in that the operation stops sequentially from the auxiliary motor first started.

In addition, when the auxiliary motor is increased and operated one by one according to the preset order, the pressure value of the pipe is fed back and the feedback signal received from the feedback is compared with the reference signal, and if the feedback signal exceeds the reference signal as a result of the comparison. First, the operation of the auxiliary motor is characterized in that the operation is stopped.

In addition, the multiple motor control apparatus according to the present invention, the PID controller for receiving a feedback of the pressure value of the pipe line and compare the feedback signal and the reference signal received from the feedback and outputs a control signal for controlling the operating frequency of the main motor according to the determination result ; When the feedback signal is less than the reference signal as a result of the determination of the PID controller, the auxiliary motors are increased one by one, and when the feedback signal is equal to or greater than the reference signal, a control signal for outputting one or more auxiliary motors is stopped. Control unit for stopping the operation of the auxiliary motor causing the interlock signal when the interlock signal is generated by any one of the auxiliary motors, and outputs a control signal for adjusting the operating frequency of the main motor to the maximum ; And a driving control signal setting unit configured to set a change time and a change frequency of the main motor and at least one auxiliary motor according to a control signal generated by the PID controller and a control signal generated by the controller.

In addition, a plurality of motor control system according to the present invention, a plurality of electric motors that operate as a main motor or an auxiliary motor; A state detection unit detecting each state of the plurality of electric motors; And the main motor is operated and the feedback value of the pipeline is fed back and the feedback signal and the reference signal are compared and the auxiliary motor is increased by one when the feedback signal is less than the reference signal, and operated when the feedback signal is higher than the reference signal. Stops the auxiliary motors that cause the interlock signal when an abnormality of any one of the auxiliary motors is detected by the state detector and an interlock signal is generated. It comprises a; a plurality of motor control device for adjusting the operating frequency of the motor to the maximum.

According to the method and apparatus for controlling a plurality of motors according to the present invention, when an interlock signal is generated by the main motor in operation, the first operation of the auxiliary motors in operation starts and stops, and finally, the main motor is stopped. The pressure change in the pipeline can be minimized.

When the interlock signal is generated by the auxiliary motor, the auxiliary motor is stopped and judged whether the next auxiliary motor is available. It can be kept constant.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

However, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, a detailed description thereof will be omitted.

Figure 1a is a configuration of a plurality of motor control system to which a plurality of motor control apparatus according to the present invention is applied, Figure 1b is a view showing the detailed configuration of the drive control signal setting unit and the relay unit in the plurality of motor control apparatus of Figure 1a.

Referring to FIG. 1A, each of the four motors 130 is connected to the output terminal of the plurality of motor control apparatus 110 through the relay 120 or directly connected to the three-phase commercial power supply unit 100 through the relay 120. It is configured to be. Here, when the output terminal of the plurality of motor control apparatus 110 and any one motor is connected, the electric motor is a main motor, other motors are auxiliary motors, the main motor can be changed and set. That is, the main motor means an electric motor controlled by the plurality of motor control apparatus 110, the auxiliary motor means an electric motor driven by a commercial power source.

Such a configuration corresponds to a plurality of motor control systems configured in a main motor change mode in which the main motor is changed. For reference, the plural motor control system may be configured in an auxiliary motor change mode in which only the auxiliary motor is changed, which is connected to the plural motor control device and the predetermined main motor, and at least one auxiliary motor is connected to the three-phase commercial power supply. It is configured to be. Hereinafter, a plurality of motor control system operating in the main motor change mode will be described by applying to the present invention as an example.

The plurality of motor control apparatus 110 controls a plurality of electric motors, and includes a PID controller 111 to receive a feedback of the pressure value of the conduit to maintain a constant pressure in the conduit. Control the operating frequency of the band (PID control) and, if necessary, to operate at least one auxiliary motor through a commercial power source to maintain a constant pressure in the pipeline.

To this end, the plurality of motor control apparatus 110 includes a drive control signal setting unit 113 for setting the change time and the change frequency of the motor and a control unit 112 for controlling the entire system.

The relay unit 120 includes at least one relay 121, 123, 125, and 127 connected to each of the electric motors, and each relay 121, 123, 125, and 127 includes a first switch contact 121-1, 123-1, 125-1, and 127-1 and second switch contacts 121-2, 123-2, 125-2, and 127-2, wherein the first switch contacts 121-1 and 123- are included. 1, 125-1, and 127-1 and the second switch contacts 121-2, 123-2, 125-2, and 127-2 operate exclusively with each other. That is, when the first switch contact comes in contact with the signal input through the line corresponding to each phase from the plurality of motor control apparatus 110, the second switch contact falls.

In the main motor change mode, the driving control signal setting unit 113 and the relay unit 120 of the plurality of motor control apparatus 110 are configured to be connected as shown in FIG. 1B, and the plurality of motor control apparatus 110 is driven. The control signal setting unit 113 sets the main motor and the auxiliary motor, and controls the change time and the change frequency of each motor. That is, when one of the electric motors becomes the main motor, the remaining motors become auxiliary motors, and the main motors can be changed.

The control unit 112 operates the main motor after setting the main motor, and receives the pressure value of the pipe line and compares the feedback signal received from the feedback signal with the reference signal. When the feedback signal is less than the reference signal, the auxiliary motors are arranged one by one in a preset order. Increase and operate.

When the feedback signal exceeds the reference signal as a result of comparing the feedback signal with the reference signal, the control unit 112 stops the auxiliary motor operated by the driving control signal setting unit 113 one by one. In the present invention, the motor is started first, and then the operation is stopped. For example, when the auxiliary motor is operated in the order of M1, M2, M4, the auxiliary motor is stopped in the order of M1, M2, M4 in the order of first operation. Such a method is called a FIFO (First Input First Out) method.

In addition, the control unit 112 receives a state signal for each of the motors from the state detection unit 140 that detects a state (for example, a current value) of each of the motors (the main motor and the auxiliary motor). Judgment is made, and an interlock signal is generated when there is an error in a specific motor (main motor or auxiliary motor). Accordingly, the generated interlock signal controls the stopping and starting sequence of the motors, stops the operation of the faulty motor, and starts the normal motor. That is, the interlock signal is a signal generated when an abnormality occurs in the main motor or the auxiliary motor, and the control unit 112 generates an interlock signal when the abnormality of the motor is determined by the state signal of each motor input. On the other hand, when the controller 112 determines the abnormality by the status signal of each of the input motors, the controller 112 may be notified to the user and receive an interlock signal corresponding to the control command from the user. The interlock signal may be classified into a signal generated when an abnormality of the main motor and a signal generated by an abnormality of the auxiliary motor.

2 to 4, a method of controlling the plurality of motors by the plurality of motor controllers when the interlock signal occurs due to the auxiliary motor and the interlock signal occurs due to the main motor will be described with reference to FIGS. 2 to 4.

2 is a flowchart illustrating a method of controlling a plurality of electric motors according to the present invention.

The plurality of motor control apparatus 110 operates the main motor (S200), receives a feedback of the pressure signal of the pipe line, compares the feedback signal with the reference signal (S202), and determines whether the feedback signal exceeds the reference signal ( S204).

As a result of the determination, when the feedback signal is less than the reference signal, the plurality of motor control apparatus 110 operates the auxiliary motor in a predetermined order (S206), receives the pressure signal of the pipe line, and compares the feedback signal with the reference signal to feedback. Run by increasing the number of auxiliary motors one by one until the signal exceeds the reference signal.

For example, if M1 is a main motor, M2, M3, and M4 are auxiliary motors, and an operation sequence is set in the order of M2, M3, M4, the multi-motor control apparatus 110 cannot control only the main motor. The auxiliary motor of M2 is operated to compare the feedback signal and the reference signal to which the flow rate of the pipe is fed back. When the feedback signal is less than the reference signal, the auxiliary motor of M3 is operated. When the feed vaccine signal is less than the reference signal, the auxiliary motor of M4 is operated by comparing the feedback signal with the feedback signal.

On the other hand, when the feedback signal exceeds the reference signal as a result of the determination in step S204, the plurality of motor control apparatus 110 stops the operation of the auxiliary motor in the order in which it was first started (S208). This is the case when at least one auxiliary motor is in operation. If the feedback signal exceeds the reference signal when only the main motor is in operation, it is preferable to control the pressure in the conduit by controlling the main motor.

For example, when M1 is a main motor, M2, M3, and M4 are auxiliary motors, and auxiliary motors are operating in the order of M2, M3, M4, the plural motor controller 110 stops the operation of the M2 auxiliary motor. Let's do it. When the feedback signal exceeds the reference signal by comparing the feedback signal with the reference signal, the operation of the M3 auxiliary motor is stopped. When the feedback signal exceeds the reference signal by comparing the feedback signal with the reference signal, the M4 auxiliary motor Stop operation This method is called FIFO (First Input First Out) method, which allows the auxiliary motor to run for an even time. This makes it possible to equally change the replacement cycle of the auxiliary motor in relation to the life time of the motor.

3 is a flowchart illustrating a method of controlling a plurality of motors according to the present invention when an interlock signal is generated by a main motor. Herein, it will be assumed that the main motor and at least one auxiliary motor are in operation.

When the interlock signal is generated by the main motor (S300), the plurality of motor control apparatus 110 stops the operation sequentially from the auxiliary motors that are first operated among the auxiliary motors in operation (S302).

When the operation of at least one auxiliary motor in operation is stopped, the plurality of motor control apparatus 110 stops the operation of the main motor (S304), and sets one of the movable auxiliary motors as the main motor after a predetermined time ( S306).

Then, the modified main motor is operated to control the pressure in the pipeline (S308).

4 is a flowchart illustrating a method of controlling a plurality of motors according to the present invention when an interlock is generated by an auxiliary motor. Similarly, it will be assumed that the main motor and at least one auxiliary motor are in operation.

When the interlock signal is generated by the auxiliary motor in operation (S400), the plurality of motor control apparatus 110 stops the operation of the auxiliary motor which is the cause of the interlock signal (S402) and maximizes the operating frequency of the main motor. Operation by adjusting to the frequency (S404).

Then, when the operation of the auxiliary motor is stopped, the plurality of motor control apparatus 110 determines whether there is a movable auxiliary motor corresponding to the next order of the stopped auxiliary motor (S406). That is, when the auxiliary motor according to the interlock signal generation is stopped, the plurality of motor control apparatus 110 determines whether there is an auxiliary motor corresponding to the next order of the stopped auxiliary motor, and determines the auxiliary motor corresponding to the next order. If there is, it is determined whether the auxiliary motor is movable.

As a result of the determination, if there is a next auxiliary motor, the next auxiliary motor is started (S408), and if there is no next auxiliary motor, it is displayed on the screen so that the manager can see it (S410). In other words, if there is no next auxiliary motor, the pressure of the pipeline is controlled by the motor which is currently operating until the troubled auxiliary motor is replaced, or by the manager being operated until the control command from the administrator To control the pressure.

Meanwhile, when the interlock signal is generated by the auxiliary motor to be operated currently (S412), the plurality of motor control apparatus 110 determines whether there is a movable auxiliary motor corresponding to the next step (S406).

As a result of the determination, when the next auxiliary motor is present, instead of the auxiliary motor to be operated currently, the auxiliary motor corresponding to the next step is operated (S408), and if there is no next auxiliary motor, this is displayed on the screen so that the administrator can see it. (S410).

5, for example, when the interlock signal P2 is generated by the auxiliary motor Motor 2 in operation, the operation of the auxiliary motor Motor 2, which is the source of the interlock signal, is stopped. Then, the motor operates at the maximum operating frequency of the motor (Moter 1). When the auxiliary motor (Moter 2) is stopped, the auxiliary motor (Moter 3), which is the next step of the stopped auxiliary motor, is operated to minimize the pressure change in the pipeline.

As described above, the plurality of motor control apparatus receives the pressure value of the detected pipe line and compares the feedback signal with the reference signal so that the pressure of the pipe line can be kept constant (on) or on (off). (Stop operation: off)

In addition, when the interlock signal is generated by the main motor or the auxiliary motor during the operation of the main motor and the at least one auxiliary motor, the plural motor control apparatus may turn on (start) or turn off (start up) the main motor and the at least one auxiliary motor. By controlling the operating sequence) is characterized in that the pressure in the conduit can be kept constant while avoiding the system itself. Referring to FIG. 6, a is a reference signal, b is a feedback signal fed back the pressure value of the pipe, and c is a comparison between the reference signal a and a feedback signal fed back the pressure value of the pipe. The number of auxiliary motors operated accordingly, d is a signal showing the change in operating frequency of the main motor. That is, the plurality of motor control apparatus controls the operating frequency of the main motor when the auxiliary motor is started or stopped, so that the main motor performs a rapid deceleration and acceleration. This minimizes the pressure change in the conduit.

On the other hand, while the invention has been shown and described with respect to specific preferred embodiments, those skilled in the art to which the present invention pertains without departing from the scope of the present invention with respect to the above-described embodiment It can be easily seen that it can be modified and changed. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1A is a view showing the configuration of a multi-motor control system to which a multi-motor control apparatus according to the present invention is applied;

FIG. 1B is a view illustrating a detailed configuration of a drive control signal setting unit and a relay unit in the plurality of motor control apparatus of FIG. 1A;

2 is a flowchart illustrating a method of controlling a plurality of electric motors according to the present invention;

3 is a flowchart illustrating a method of controlling a plurality of motors according to the present invention when an interlock signal is generated by a main motor;

4 is a flowchart illustrating a method of controlling a plurality of motors according to the present invention when an interlock signal is generated by an auxiliary motor;

5 is a view showing the operation of the motor according to the invention when the interlock signal is generated by the auxiliary motor, and

6 is a diagram illustrating a method of controlling a plurality of motors by a plurality of motor control apparatus in accordance with the present invention.

* Description of the main symbols in the drawing

110: plural motor control device 111: PID controller

112: control unit 113: driving control signal setting unit

130: motor unit 140: state detection unit

Claims (14)

Operating the main motor, receiving a feedback pressure value, and comparing the feedback signal with the reference signal; Increasing and starting the auxiliary motors one by one in a preset order when the feedback signal is less than the reference signal; And When an interlock signal is generated by any one of the at least one auxiliary motor operated, the operation of the auxiliary motor causing the interlock signal is stopped, and the operating frequency of the main motor is maximized. And adjusting the plurality of motors. The method of claim 1, After the operation of the auxiliary motor that causes the interlock signal is stopped, Determining whether there is an auxiliary motor corresponding to a next step of the stopped auxiliary auxiliary motor; Determining whether the next auxiliary motor is movable when there is a next auxiliary motor corresponding to a next step as a result of the determination; And And when the next auxiliary motor is movable, operating the next auxiliary motor as a result of the determination. The method of claim 1, While increasing and operating the auxiliary motors one by one according to the preset order, If an interlock signal is generated by the auxiliary motor to be operated at present, determining whether the auxiliary motor corresponds to the next step; Determining whether the next auxiliary motor is movable when there is a next auxiliary motor corresponding to a next step as a result of the determination; And And when the next auxiliary motor is movable, operating the next auxiliary motor as a result of the determination. The method of claim 1, Stopping at least one of the operated auxiliary motors one by one when an interlock signal is generated due to an abnormality in the operating main motor and stopping operation of the main motor; And Stopping the operation of the at least one auxiliary motor and the main motor, changing and setting any one of the at least one auxiliary motor operable to the main motor after a predetermined time, and starting the changed set main motor; A plurality of motor control method characterized in that. The method of claim 4, wherein The stop operation of the at least one auxiliary motor operated A method of controlling a plurality of motors, characterized in that the starting operation of the auxiliary motor first started to stop sequentially The method of claim 1, While increasing and operating the auxiliary motors one by one according to the preset order, Receiving a pressure value of the pipe and comparing the feedback signal received with the reference signal, and when the feedback signal exceeds the reference signal as a result of the comparison, controlling the plurality of motors, starting from the auxiliary motor first started. A PID controller for receiving a pressure value of a pipe and comparing the feedback signal received from the feedback signal with a reference signal and outputting a control signal for controlling an operating frequency of the main motor according to a determination result; When the feedback signal is less than the reference signal as a result of the determination of the PID controller, the auxiliary motors are increased one by one, and when the feedback signal is equal to or greater than the reference signal, a control signal for outputting one or more auxiliary motors is stopped. When an interlock signal is generated by any of the auxiliary motors of the motors, the operation of the auxiliary motors causing the interlock signal is stopped and a control signal for adjusting the operating frequency of the main motor to the maximum is output. Control unit; And And a driving control signal setting unit configured to set a change time and a change frequency of the main motor and at least one auxiliary motor according to a control signal generated by the PID controller and a control signal generated by the controller. The method of claim 7, wherein The interlock signal is And a state signal generated by a state signal output by a state detector for detecting a state of each of the main motor and at least one auxiliary motor. The method of claim 7, wherein The control unit When the interlock signal is generated by the auxiliary motor to be operated at present, it is determined whether there is a flexible auxiliary motor corresponding to the following sequence, and when there is a next auxiliary motor that is movable, a control signal for operating the next auxiliary motor is generated. A plurality of motor control device, characterized in that. The method of claim 7, wherein The control unit When an abnormality occurs in the operating main motor and an interlock signal is generated, the at least one auxiliary motor operated by the driving control signal generator is stopped one by one, and then the operation of the main motor is stopped, and After the time has passed, a plurality of motor control apparatus characterized in that any one of the at least one auxiliary motor can be changed to the main motor to operate. The method according to claim 7 or 10, The control unit When the at least one auxiliary motor is stopped, the plurality of motor control apparatus characterized in that the starting operation of the auxiliary motor first started first. A plurality of electric motors operating as main or auxiliary electric motors; A state detection unit detecting each state of the plurality of electric motors; And When the main motor is operated and the feedback value of the pipeline is fed back, the feedback signal is compared with the reference signal, and the auxiliary motor is increased by one when the feedback signal is less than the reference signal, and operated when the feedback signal is higher than the reference signal. Stop the auxiliary motors one by one, but stop the operation of the auxiliary motor that causes the interlock signal when an interlock signal is generated due to an abnormality in any one of the auxiliary synchronizations detected by the state detector. A plurality of motor control system comprising; a plurality of motor control device for adjusting the operating frequency of the motor to the maximum. The method of claim 12, The plurality of motor control device When an abnormality of the main motor is detected by the state detecting unit and an interlock signal is generated, the at least one auxiliary motor operated by the driving control signal generator is stopped one by one, and then the operation of the main motor is stopped. And changing and setting any one of the at least one auxiliary motors operable to the main electric motor after a predetermined time has elapsed. The method of claim 13, The plurality of motor control device When the at least one auxiliary motor is stopped, the plurality of electric motor control system characterized in that the starting operation of the auxiliary motor first started.

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