JP2010020451A - Method for starting inductive load device or resistive load device and device for starting software for single phase - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a new inductive load device or a method for starting a resistive load device and a device for starting software for a single phase for performing various start operations corresponding to the characteristics of a negative load. <P>SOLUTION: This start method is characterized by performing phase control to adjust the voltage effective value of an output by controlling the timing of a trigger pulse to be supplied to a semiconductor switch 11, setting arbitrarily a start voltage, setting arbitrarily the time from the start voltage to a full voltage, and conducting a step-up operation to simultaneously shift the start voltage to the full voltage at the point of time when a phase angle in the phase control becomes a prescribed value in a stage during the shift of the start voltage to the full voltage. Since the optimal rising time can be arbitrarily set, it is possible to smoothly increase output or currents, and to sharply improve the lifetime of the load device itself and equipment connected to the load device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a starting method and device for suppressing an inrush current when an inductive load device or a resistive load device is started, and in particular, the output and current of the load device can be increased smoothly, and the load device The present invention relates to a starting method and apparatus capable of performing various starting operations according to the characteristics of the above.

Inductive load devices such as single-phase motors, or resistive load devices such as heaters and lighting, when full voltage is applied during startup, an inrush current much larger than the steady current flows, fuse blown, circuit breaker Disconnection, welding of power switch contacts, etc. may occur.
These phenomena can be avoided by using an element according to the magnitude of the inrush current, but this leads to an increase in cost, and the fuse and breaker function against abnormalities during normal use. There will also be negative effects such as failure to do so.
In addition, in the inductive load device, noise is generated at the stage from the start-up current to the steady current, which adversely affects the devices connected to the load device.

  For this reason, the voltage applied to the load device during startup is kept low and gradually increased so that the current during startup does not flow excessively and is increased to the full voltage before the steady current is reached. (For example, refer to Patent Document 1).

JP 2006-288907 A

The device disclosed in the above patent application captures the waveform of the current flowing in the power supply line with CT, finds the maximum value of the current with a current detection circuit from the rectified current, and outputs all to the thyristor when the current peak is detected. Feedback control such as sending a signal is performed, and control such that the voltage is rapidly increased when a current peak is detected can be reliably performed.
However, a resistance load device such as a lamp heater has a resistance value that changes linearly with temperature. The resistance value is the lowest at start-up, and then increases as the temperature rises, gradually increasing the voltage. In such a case, the peak of the current is not detected, so that it could not be applied to such a resistance load device.

  The present invention has been made in view of such a background, and can increase the output and current of the load device smoothly, and can be applied not only to an inductive load device but also to a resistive load device. The technical problem is to develop a novel inductive load device or resistance load device starting method capable of performing various starting operations in accordance with the characteristics of the load device and a single-phase soft starter.

That is, the method for starting the inductive load device or the resistive load device according to claim 1 is a method for reducing inrush current at startup by adjusting the power supplied to the single-phase inductive load device or the resistive load device. This method controls the timing of the trigger pulse supplied to the semiconductor switch and performs phase control to adjust the effective voltage value of the output. From the starting voltage to the full voltage, the starting voltage is arbitrarily set. In addition, when the phase angle in the phase control reaches a predetermined value in the midway from the starting voltage to the full voltage, a step-up operation for shifting to the full voltage at once is performed. It is characterized by being.
According to the present invention, since the optimal rise time can be arbitrarily set, an optimal starting torque can be obtained in the case of an inductive load device, and the output and current can be increased smoothly, The life of the inductive load device itself and the equipment connected to the inductive load device can be dramatically improved. Further, even a resistive load device in which the value of the current flowing through the power supply line does not have a peak when the voltage is gradually increased can be applied.
For this reason, a load apparatus can be operated efficiently in the situation where power supply capacity was limited, such as a ship.
Further, by suppressing the current at the time of startup, it is possible to avoid a power flicker phenomenon and a voltage drop.

In addition to the above requirements, the step-up operation of the inductive load device or the resistive load device according to claim 2 is characterized in that the phase control of the semiconductor switch is set to full voltage. .
According to the present invention, the step-up operation can be performed with the minimum necessary circuit configuration.

Furthermore, the starting method of the inductive load device or the resistive load device according to claim 3 is characterized in that, in addition to the requirement of claim 1, the step-up operation directly connects the power source and the load device. It consists of.
According to the present invention, since no semiconductor switch is used during steady operation, excessive heat generation can be eliminated and power saving operation can be performed.

In addition, the single-phase soft starter according to claim 4 is a device for reducing inrush current at start-up by adjusting power supplied to a single-phase inductive load device or a resistive load device. Phase control to control the trigger pulse timing supplied to the semiconductor switch to adjust the effective voltage value of the output, and means for arbitrarily setting the starting voltage, and from the starting voltage to the full voltage Means for arbitrarily setting the period of time, and in the middle from the starting voltage to the full voltage, when the phase angle in the phase control reaches a predetermined value, the full voltage is The present invention is characterized by comprising means for performing a step-up operation for shifting to (1).
According to the present invention, since the optimal rise time can be arbitrarily set, an optimal starting torque can be obtained in the case of an inductive load device, and the output and current can be increased smoothly, The life of the inductive load device itself and the equipment connected to the inductive load device can be dramatically improved. Further, even a resistive load device in which the value of the current flowing through the power supply line does not have a peak when the voltage is gradually increased can be applied.
For this reason, a load apparatus can be operated efficiently in the situation where power supply capacity was limited, such as a ship.
Further, by suppressing the current at the time of startup, it is possible to avoid a power flicker phenomenon and a voltage drop.

Furthermore, in the soft starter for single phase according to claim 5, in addition to the requirement according to claim 4, the means for performing the step-up operation is to make the phase control of the semiconductor switch full voltage. It is characterized by this.
According to the present invention, the step-up operation can be performed with the minimum necessary circuit configuration.

Furthermore, in the single-phase soft starter according to claim 6, in addition to the requirement of claim 4, the means for performing the step-up operation is a bypass circuit directly connecting a power source and a load device. Is a feature.
According to the present invention, it is possible to perform an operation without using a semiconductor switch during a steady operation, so that excessive heat generation can be eliminated, power saving operation can be performed, and the life of the single-phase starter is extended. be able to.
The above problems can be solved by using the configuration of the invention described in each of the claims as a means.

  According to the present invention, not only an inductive load device but also a resistive load device can smoothly increase the output and current of the load device and can perform various starting operations according to the characteristics of the load device. This can extend the product life of the load device and its peripheral devices.

One of the best modes for carrying out the present invention is as described in the following embodiments. First, the configuration of the single-phase soft starter will be described, and then the operation mode of this device will be described. A method for starting the inductive load device or the resistive load device of the present invention will be described.
It should be noted that the following embodiments can be appropriately modified within the scope of the technical idea of the present invention.

As shown in FIG. 1, the single-phase soft starter 1 of the present invention is connected to a circuit formed by a single-phase AC power source 2 (hereinafter simply referred to as a power source 2) and a load device 3. By adjusting the effective power supplied to the load device 3, the load device 3 and peripheral devices are protected by reducing the inrush current when the load device 3 is started.
This single-phase soft starter 1 includes a phase control device 10, a semiconductor switch 11, a zero-cross signal output device 12, and a start switch 13 as main components, which will be described below.

First, the phase control device 10 is a device for sending a trigger pulse to the semiconductor switch 11 at an appropriate timing. As an example, a general-purpose microcomputer is applied.
The semiconductor switch 11 is applied with a bi-directional thyristor (triac) as an example, which is configured such that two thyristors are connected in antiparallel to allow a current to flow in both directions. As the semiconductor switch 11, a GTO thyristor, a THY thyristor, an IGBT, or the like can be applied.
The zero-cross signal output unit 12 is configured to include a high-precision comparator, and is a device for monitoring the output waveform of the power supply 2 and sending a zero-cross signal through the zero-cross signal line 120.

  Then, the phase control device 10 determines the trigger pulse transmission timing to be output to the semiconductor switch 11 through the trigger pulse line 110 based on the zero cross signal, and adjusts the effective voltage value of the output of the semiconductor switch 11. Is to execute. That is, as shown in FIG. 2A, when the trigger pulse is output at the timing of 2 / π and 3 / 4π, the effective voltage value of the output of the semiconductor switch 11 is 50%, and FIG. As shown, when the trigger pulse is output at the timing of 0 and π, the effective voltage value of the output of the semiconductor switch 11 is 100% (total voltage).

The single-phase soft starter 1 includes means for arbitrarily setting the start voltage of the load device 3 and means for arbitrarily setting the time from the start voltage to the full voltage. And a means for carrying out a step-up operation for shifting to the full voltage at once when the phase angle in the phase control reaches a predetermined value in the middle of the process from the starting voltage to the full voltage. .
Specifically, referring to FIG. 3, when the voltage at start-up is to be 50% of the total voltage as shown by point A in FIG. 3 (a), as shown in FIG. 2 (a). In addition, a trigger pulse is transmitted at a timing such that the effective voltage value of the output of the semiconductor switch 11 is 50%. As a means for this, it is connected to an internal circuit of the phase control device 10 as an example. The variable resistor VR1 is provided, and by adjusting the value of the variable resistor VR1, the trigger pulse transmission timing is determined, and the value of the point A can be selected.
In this embodiment, as an example, the starting voltage can be set between 0 to 50% of the total voltage.

As a means for arbitrarily setting the time from the starting voltage to the full voltage (hereinafter referred to as the rise time), a variable resistor VR2 connected to the internal circuit of the phase control device 10 is provided as an example. By adjusting the value of the variable resistor VR2, the value of t ₁ (point B) shown in FIG. 3B, that is, the rise time can be selected. Specifically, the voltage applied to the load device 3 starts at a value indicated by point A (50%) and reaches the total voltage (100%) at point B after time t _{1 has} elapsed. 2 is sent from the state shown in FIG. 2 (a) to the state shown in FIG. 2 (c) through the state shown in FIG. 2 (b).
In this embodiment, as an example, the rise time can be set between 2 and 33 seconds.

Furthermore, in the present invention, a step-up operation for shifting to the full voltage at once is performed when the phase angle in the phase control reaches a predetermined value in the middle of the process from the starting voltage to the full voltage. As a means for setting the angle, for example, a variable resistor VR3 connected to an internal circuit of the phase control device 10 is provided. Then, by adjusting the value of the variable resistor VR3, the position of the point C (step-up voltage value) shown in FIG. 3C can be selected by the phase angle.
In this embodiment, the step-up voltage value can be set between 60% and 90% of the total voltage.

  The single-phase soft starter 1 of the present invention is configured as described above as an example, and subsequently, the start method of the inductive load device or the resistive load device of the present invention will be described together with the operation mode of this device. .

(1) Starting of an inductive load device When starting a single-phase induction motor as the load device 3, the variable resistor VR1 is first adjusted as a preparation stage, and the voltage at the time of start-up is taken as an example in FIG. , Set to 50% of the total voltage as shown by point A.
Next, the position of B point (rise time) shown in FIG. 3B is set by adjusting the variable resistance VR2, and in this embodiment, 30 seconds is set as an example.
Further, the position of the point C (step-up voltage value) shown in FIG. 3C is set by adjusting the variable resistor VR3. In this embodiment, 80% of the total voltage is set as an example.

Each set value as described above is selected according to the characteristics of the single-phase induction motor that is the load device 3, and the relationship among the voltage value, current value, and torque value with respect to the time axis is shown in FIG. The state shown in (a) is set. That is, since the output voltage of the semiconductor switch 11 gradually increases from a state where the output voltage is suppressed to 50% of the total voltage, a current value gradually increases and a rush current is suppressed. Further, a curve is also drawn for the torque that gradually increases from the start.
When the phase control device 10 detects from the phase angle value that the output voltage of the semiconductor switch 11 has reached 80% of the total voltage, the current tends to decrease. The step-up operation is performed, and the trigger pulse transmission timing is set to the state shown in FIG.
As a result, the output and current of the inductive load device can be increased smoothly, and noise can be avoided in the process of reaching a steady state.

  Incidentally, the relationship among the voltage value, current value and torque value with respect to the time axis when the single-phase induction motor which is the load device 3 is started at all voltages is as shown in FIG. Inrush current that is several times the normal value will flow.

(2) Starting of the resistive load device When starting up the resistive load device as the load device 3, by adjusting the variable resistor VR1 as a preparatory step, the voltage at the time of startup is set to 50% of the total voltage as an example. Set.
Next, the rise time is set by adjusting the variable resistor VR2. In this embodiment, 10 seconds is set as an example.
Further, the step-up voltage value is set by adjusting the variable resistor VR3, and in this embodiment, 90% of the total voltage is set as an example.

Each set value as described above is selected according to the characteristics of the resistive load device as the load device 3, and the relationship between the voltage value and the current value with respect to the time axis is shown in FIG. Set to be in the indicated state. That is, since the output voltage of the semiconductor switch 11 gradually increases from a state where the output voltage is suppressed to 50% of the total voltage, a current value gradually increases and a rush current is suppressed.
When the phase control device 10 detects from the phase angle value that the output voltage of the semiconductor switch 11 has reached 90% of the total voltage, the current is approaching the steady current, and at this point, the current shifts to the full voltage all at once. The step-up operation is performed, and the trigger pulse transmission timing is set to the state shown in FIG.
In this way, by applying the present invention to a resistive load that has the lowest resistance value at the time of start-up and whose resistance value increases thereafter as the temperature rises, it is possible to perform an operation with reduced inrush current. For this reason, damage to the resistance load device can be avoided.

[Other Examples]
The present invention is based on the above-described embodiment, but the following embodiment can be adopted based on the technical idea of the present invention.
In other words, in the basic embodiment described above, the step-up operation is performed by setting the phase control of the semiconductor switch 11 to the full voltage, but the power source 2 and the load device 3 may be directly connected.
Specifically, as shown in FIG. 6 as an example, this is realized by a configuration in which a bypass switch 4 and a bypass circuit 5 are added to the circuit of FIG. 1, and pulse transmission to the triac 11A is stopped. By sending a pulse to the triac 11B, the bypass switch 4 is turned on to obtain a state where the power source 2 and the load device 3 are directly connected. Note that once the bypass switch 4 is turned on (off state), the bypass switch 4 is maintained in the on state (off state) even if pulse transmission is stopped.
And when such a method is taken, since the semiconductor switch 11 is not used at the time of the steady operation after the step-up operation is performed, excessive heat generation can be eliminated and power saving operation can be performed.

It is a circuit diagram which shows the load apparatus drive circuit to which the soft starter for single phases of this invention was connected. It is a graph which shows the trigger pulse and output in phase control. It is a graph which shows the load apparatus voltage at the time of starting by this invention in steps. It is a graph which shows the voltage at the time of starting of the inductive load apparatus by this invention, an electric current, and a torque, and the graph which shows the voltage at the time of starting of the inductive load apparatus when it puts in directly, an electric current, and torque. It is a graph which shows the voltage and electric current at the time of starting of the resistive load apparatus by this invention, and the voltage and electric current at the time of starting of the inductive load apparatus when it puts in directly. It is a circuit diagram which shows an Example as a step-up operation | movement as what connects a power supply and a load apparatus directly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soft start apparatus for single phases 2 (Single phase alternating current) Power supply 3 Load apparatus 4 Bypass switch 5 Bypass circuit 10 Phase control apparatus 11 Semiconductor switch 11A Triac 11B Triac 110 Trigger pulse line 12 Zero cross signal output device 120 Zero cross signal line 13 Start switch VR1 Variable resistance VR2 Variable resistance VR3 Variable resistance

Claims (6)

  In a method to reduce the inrush current at startup by adjusting the power supplied to the single-phase inductive load device or resistive load device, this method controls the output of the trigger pulse supplied to the semiconductor switch. Phase control is performed to adjust the effective voltage value. The starting voltage is arbitrarily set, the time from the starting voltage to all voltages is arbitrarily set, and further, from the starting voltage to all voltages. A starting method for an inductive load device or a resistive load device, wherein a step-up operation of shifting to a full voltage at once is performed at a point in time when the phase angle in phase control reaches a predetermined value.   2. The method for starting an inductive load device or a resistive load device according to claim 1, wherein the step-up operation is to set the phase control of the semiconductor switch to full voltage.   2. The method for starting an inductive load device or a resistive load device according to claim 1, wherein the step-up operation directly connects a power source and a load device.   In the device to reduce the inrush current at the start-up by adjusting the power supplied to the single-phase inductive load device and the resistive load device, this device controls the timing of the trigger pulse supplied to the semiconductor switch and outputs it Is a phase control for adjusting the effective voltage value, and includes means for arbitrarily setting the starting voltage and means for arbitrarily setting the time from the starting voltage to the entire voltage. In addition, there is provided means for carrying out a step-up operation for shifting to the full voltage at once when the phase angle in the phase control reaches a predetermined value in the stage from the starting voltage to the full voltage. A soft starter for single phase.   5. The single-phase soft starter according to claim 4, wherein the means for performing the step-up operation sets the phase control of the triac to full voltage.   The single-phase soft starter according to claim 4, wherein the means for performing the step-up operation is a bypass circuit that directly connects a power source and a load device.

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