JP4599702B2 - Inverter operation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for operating an inverter such as a general-purpose inverter.
[0002]
[Prior art]
FIG. 3 is a circuit configuration diagram of a general-purpose inverter showing a conventional example of an operation method of this type of inverter, wherein 1 is an AC power source such as a commercial power source, 2 is a conventional general-purpose inverter, and 3 is a general-purpose inverter 2 and is driven at a variable speed. It is an electric motor.
[0003]
The general-purpose inverter 2 includes a diode rectifier 11 that rectifies the voltage of the AC power source 1, a capacitor 12 that smoothes the rectified voltage of the diode rectifier 11, and a voltage across the capacitor 12 as a DC input voltage. , An inverter circuit 13 that converts the voltage into alternating current and supplies power to the motor 3, a frequency setting unit 14 that sets a frequency command value (ω ^* ) of the frequency output from the inverter circuit 13, and the frequency command value (ω ^* ) When is changed, the frequency setting value (ω ^** ) output at a predetermined gradient (frequency change rate per unit time) is increased or decreased, and finally calculated so that ω ^** = ω ^* a deceleration calculator 15, corresponding to the frequency setting value (omega ^**), a voltage calculator 16 which outputs a voltage set value of the voltage inverter circuit 13 outputs a (V ^*), the frequency setting value omega ^**) and performs a PWM (Pulse Width Modulation) operation based voltage setting value (V ^*), the on to the self-turn-off elements constituting the inverter circuit 13 by the calculation result, PWM outputs an OFF signal The state of the arithmetic unit 17 and the external circuit 4 as the operation command circuit of the general-purpose inverter 2 is input from N command input terminals A _K (K = 1, 2, 3,..., N). Depending on the state of the circuit 4, the frequency setting device 14, the acceleration / deceleration computing device 15, the voltage computing device 16, and the PWM computing device 17 are configured with an interface circuit 18 that controls the operation of each.
[0004]
The external circuit 4 includes, for example, a contact circuit as shown, and considered to this contact is the command input terminal A _K when viewed while closing the command input terminal is in the closed state and, the command input terminal a _K when viewed state contacts of the contact circuit is opened from the command input terminal is regarded to be in an open circuit state.
[0005]
Conventionally, in general, when a command input terminal A _K is in the closed state, as a command from the command input terminal is inputted, the frequency setter 14 via the interface circuit 18, acceleration and deceleration calculator 15, A predetermined operation is performed on at least one of the voltage calculator 16 and the PWM calculator 17.
[0006]
[Problems to be solved by the invention]
For example, in a general-purpose inverter 2 that drives a motor 3 as a power source of various industrial machines at a variable speed, an external circuit 4 serving as an operation command circuit for the general-purpose inverter 2 is manufactured and commanded by the manufacturer of the industrial machine. It is in charge of the work of connecting to the a _K.
[0007]
However, as described above, when the command input terminal A _K is in the closed state, when so as to a predetermined operation to the general-purpose inverter 2 as a command from the command input terminal is input, in the external circuit 4 In order to achieve the matching, an additional circuit such as a logic inverting circuit may be required. As a result, the circuit configuration of the external circuit 4 is complicated and the cost is increased.
[0008]
An object of the present invention is to provide an inverter operating method that solves the above problems.
[0009]
[Means for Solving the Problems]
This first invention is an operation method of an inverter having a command input terminal,
When a predetermined operation is performed on the inverter by a command input to the command input terminal from an external circuit connected to the command input terminal, either the closed state or the open state of the contact of the external circuit The state can be selected programmable,
The command is input to the command input terminal when the external circuit is in the selected state.
[0010]
According to a second aspect of the present invention, in the inverter operating method of the first aspect of the invention,
The operation of selecting the state of the external circuit in a programmable manner is performed by the inverter.
[0011]
Furthermore, a third invention is an operation method of an inverter according to the second invention,
The operation of selecting the state of the external circuit in a programmable manner is performed by setting from an operation panel provided inside the inverter.
[0012]
According to this invention, it is possible to select programmably by the inverter that the command is input as either the closed state or the open state of the contact of the external circuit connected to the command input terminal. The circuit configuration of the external circuit can be simplified.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit configuration diagram of a general-purpose inverter showing an embodiment of an inverter operating method according to the present invention. Components having the same functions as those of the conventional configuration shown in FIG. A duplicate description is omitted.
[0014]
That is, the general-purpose inverter 5 shown in FIG. 1 differs from the general-purpose inverter 2 shown in FIG. 3 in that it includes an interface circuit 51 and a state setter 52 instead of the interface circuit 18, and is replaced with the external circuit 4 and will be described later. The external circuit 4a.
[0015]
The state of the external circuit 4a as an operation command circuit such as the forward rotation command and free run command of the general-purpose inverter 5 is input from N command input terminals A _K (K = 1, 2, 3,..., N). Depending on the state of the external circuit 4a, an operation predetermined for at least one of the frequency setter 14, the acceleration / deceleration calculator 15, the voltage calculator 16, and the PWM calculator 17 is performed via the interface circuit 51. The interface circuit 51 and the state setting unit 52 can programmatically select the state of the external circuit 4a, that is, the state of the contact shown in FIG. It is assumed that the command is input to the command input terminal when the state is reached.
[0016]
Here, FIG. 2 is a circuit configuration diagram showing an example of an external circuit, (a) shows a circuit configuration diagram of a conventional example, (b) shows a circuit configuration diagram of an embodiment of the present invention, and FWD is The forward rotation command input terminal, BX is a free run command input terminal, and CM is a common terminal.
[0017]
In FIG. 2A, the forward rotation command input terminal FWD starts the forward rotation operation when the contact is closed and the forward rotation command is input, and decelerates and stops when the contact is open. In addition, the free run command input terminal BX can be operated with the contact point in the closed state and the motor M being free run, assuming that the free run command has been input. However, the free-run command is given priority over the normal operation command.
[0018]
In such a conventional example, when it is desired to make the free run stop when stopping the motor M, the contact of the normal rotation command input terminal FWD is opened and the contact of the free run command input terminal BX is closed. When the operation of the motor M is to be resumed, the contact of the free run command input terminal BX must be opened and the contact of the normal rotation command input terminal FWD must be closed. As a result, there is a difficulty in complicating the circuit configuration.
[0019]
On the other hand, in the present invention, when it is desired to stop the motor M when the motor M is stopped, as shown in FIG. 2B, the contact points of the forward rotation command input terminal FWD and the free run command input terminal BX are made common. .
[0020]
At this time, the state setter 52 sets the forward rotation command input terminal FWD so that the forward rotation command is input when the contact is closed and the operation starts, and when the contact is open, the operation is decelerated and stopped. The terminal BX is set so that the contact is open and a free-run command is input, the motor M is free-run, and the contact is operable when the contact is closed.
[0021]
If the setting is made as described above, when the motor M is to be stopped, if it is desired to make a free-run stop, the stop command is input to the forward rotation command input terminal FWD only by opening the contact, and free A free run command is input to the run command input terminal BX. When the operation of the motor M is resumed, the normal rotation command is input to the normal rotation command input terminal FWD and the operation command is input to the free run command input terminal BX simply by closing the contact. Will be entered.
[0022]
As a result, the external circuit 4a has the same function as the conventional external circuit 4, but does not require an additional contact circuit or logic circuit for matching the external circuit 4a and the general-purpose inverter 5. .
[0023]
The functions of the interface circuit 51 and the state setting device 52 can be easily set by a microcomputer program provided in a recent general-purpose inverter and setting from an operation panel for setting the operation value of the general-purpose inverter and displaying the operation state. The cost increase of the general-purpose inverter for realizing this can be ignored.
[0024]
In FIG. 1, a contact circuit is shown as an example of the configuration of the external circuit 4a. However, the contact circuit is composed of a semiconductor switch such as a transistor, and the on / off state of the semiconductor switch is selected by the interface circuit 51 and the state setting device 52. May be.
[0025]
【The invention's effect】
According to the present invention, for example, the contact of the external circuit connected to the command input terminal provided in the inverter allows the inverter to select either the closed circuit state or the open circuit state by the inverter, and the selected state. By causing the inverter to perform a predetermined operation when the external circuit is formed, the circuit configuration of the external circuit can be simplified and the cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of a general-purpose inverter showing an embodiment of an inverter operating method according to the present invention. FIG. 2 is a circuit configuration diagram showing an example of an external circuit, (a) is a circuit configuration diagram of a conventional example, b) is a circuit configuration diagram of an embodiment of the present invention. FIG. 3 is a circuit diagram of a general-purpose inverter showing a conventional example of an inverter operation method.
DESCRIPTION OF SYMBOLS 1 ... AC power source, 2 ... General-purpose inverter, 3 ... Electric motor, 4, 4a ... External circuit, 5 ... General-purpose inverter, 11 ... Diode rectifier, 12 ... Capacitor, 13 ... Inverter circuit, 14 ... Frequency setting device, 15 ... Acceleration / deceleration An arithmetic unit, 16 ... a voltage arithmetic unit, 17 ... a PWM arithmetic unit, 18, 51 ... an interface circuit, 52 ... a state setter.

Claims (3)

An operation method of an inverter having a command input terminal,
When a predetermined operation is performed on the inverter by a command input to the command input terminal from an external circuit connected to the command input terminal, either the closed state or the open state of the contact of the external circuit The state can be selected programmable,
An inverter operating method, wherein the command is input to the command input terminal when the external circuit is in the selected state. In the operation method of the inverter according to claim 1,
An operation method of an inverter, wherein an operation for selecting a state of the external circuit in a programmable manner is performed by the inverter. In the operating method of the inverter according to claim 2,
An operation method for an inverter, wherein an operation for selecting a state of the external circuit in a programmable manner is performed by setting from an operation panel provided in the inverter.

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