KR100217861B1 - Spontaneous low voltage high speed detecting apparatus - Google Patents

Abstract

The present invention relates to an instantaneous low voltage detection device used for an instantaneous low voltage compensator and the like, and more particularly, to an instantaneous low voltage high speed detection device capable of detecting an instantaneous low voltage at which voltage drops momentarily on a voltage line at high speed.

In the present invention, unlike the conventional detection device that can detect only 1/4 cycle, instantaneous low voltage detection is performed even if there is only one reference voltage for detecting the instantaneous low voltage even when the reset cycle is 1/8 cycle or 1/16 cycle of the use frequency. As a result, the response speed of the low voltage detector is faster than 1/8 cycle.

Description

Instantaneous low voltage high speed detection device

The present invention relates to an instantaneous low voltage detection device used for an instantaneous low voltage compensator and the like, and more particularly, to an instantaneous low voltage high speed detection device capable of detecting an instantaneous low voltage at which voltage drops momentarily on a voltage line at high speed.

In general, a device such as a device or a system receives a power supply voltage from a power supply in an operation state, and an instantaneous low voltage at which the provided voltage drops momentarily may cause a fatal damage to the device or a system. The instantaneous low voltage at which the power supply voltage drops momentarily must be detected and appropriate measures must be taken.

As described above, the conventional apparatus for detecting the instantaneous low voltage is shown in FIG. 1, and referring to FIG. 1, the conventional instantaneous low voltage detecting device is a square wave voltage Vp synchronized with the input power supply voltage Vs. And a standard sine wave generator 20 for generating a standard sine wave voltage Vsin based on the square wave voltage Vp from the synchronous signal generator 10, and the standard sine wave. Subtraction which outputs the voltage difference between the full-wave rectifier 32 and 34 for full-wave rectification of the voltage Vsin and the input power supply voltage Vs, and the two voltages Vsin (*) and Vs (*) respectively. Group 36 and an integrator 50 for integrating the difference voltage from the subtractor 36 according to a 1/4 reset period of the use frequency.

FIG. 2 is an output waveform diagram of FIG. 1, wherein the upper waveform of FIG. 2 is for the standard sine wave voltage Vsin and the input power supply voltage Vs, and the middle waveform is for the difference voltage between the two voltages. The waveform of is integrated.

The waveform at the bottom of FIG. 2 is an output waveform of the integrator 50, which is non-linearly changing, for one quarter periods from the reference voltage set for detecting the instantaneous low voltage in the rear comparator of the integrator 50. Since all of the output maximum values of the integrator 50 are large, instantaneous low voltage detection is possible in the comparator. However, as shown in FIG. 3, when the reset period is set to 1/8 of the commercial frequency, the 1/8 period is used. Since the output waveform maximum value of the integrator 50 may be lower than the reference voltage set by the comparator, instantaneous low voltage detection is impossible in the comparator.

As described above, in order to detect the instantaneous low voltage in the case of resetting in the 1/8 period, one additional reference voltage Vref2 lower than the reference voltage Vref1 set in the case of resetting in the 1/4 period must be set.

Therefore, the conventional instantaneous low voltage detection device is capable of detecting the instantaneous low voltage only at a low speed with one reference voltage, is impossible at high speed, and has two different reference values to detect the instantaneous low voltage at high speed. Since the voltage must be set, this is a problem, such as the difficulty of the circuit configuration.

The present invention has been made to solve the above problems.

Accordingly, an object of the present invention is to provide an instantaneous low voltage high speed detection device capable of quickly detecting an instantaneous low voltage at which a voltage drops instantaneously below a set voltage on a voltage line even with one reference voltage setting in a rear comparator of an integrator. .

1 is a block diagram of a conventional instantaneous low voltage detection device.

2 is an output waveform diagram of FIG.

3 is an integrated output waveform diagram of FIG. 1 according to a 1/8 reset period.

4 is a block diagram of an instantaneous low voltage high speed detection apparatus according to the present invention.

5 is a detailed view of the division circuit part of FIG.

6 is an output waveform diagram of FIG.

7 is a waveform showing the instant of occurrence of the instantaneous low voltage.

8 is a histogram comparing the conventional low voltage detection speed with the detection speed according to the present invention.

* Explanation of symbols for main parts of the drawings

10: synchronization signal generator 20: standard sine wave generator

32,34: first and second full-wave rectifier 40: division circuit

50: Integrator Vs: Input Power Voltage

Vsin: Sine wave voltage Vs (*): Rectified power supply voltage

Vsin (*): Rectified sine wave voltage Vd: Integral output voltage

As a technical means for achieving the above object of the present invention, the device of the present invention outputs a square wave voltage in synchronization with the phase of the input power supply voltage and at the same time set by the zero-crossing detection method for the input power supply voltage. A synchronous signal generator for outputting a reset signal, a standard sine wave generator for generating a standard sine wave voltage based on a square wave voltage from the synchronous signal generator, a first full-wave rectifier for full-wave rectifying the standard sine wave voltage, and An instantaneous low voltage detection device comprising a second full-wave rectifier for full-wave rectifying an input power supply voltage, the instantaneous low voltage detection device comprising: providing an integrator with a result value obtained by dividing a standard sine wave voltage from the first full-wave rectifier by a power supply voltage from the second full-wave rectifier; A division circuit unit; An integrator for integrating a value provided from the division circuit unit according to a set reset period and providing the result to a comparator; And a comparator for comparing the integral value provided from the integrator with a preset reference value and outputting an instantaneous low voltage detection signal when the integral value is larger than the reference value.

Hereinafter, a preferred embodiment of the instantaneous low voltage high speed detection apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In the drawings referred to in the present invention, components having substantially the same configuration and function will use the same reference numerals.

4 is a block diagram of the instantaneous low voltage high speed detection device according to the present invention. Referring to FIG. 4, the instantaneous low voltage high speed detection device according to the present invention is a square wave voltage Vp in synchronization with the phase of the input power supply voltage Vs. And a square wave voltage from the sync signal generator 10 and a sync signal generator 10 for outputting a preset reset signal by a zero-crossing detection method for the input power voltage Vs. A standard sine wave generation unit 20 for generating a standard sine wave voltage Vsin based on Vp, a first full wave rectifying unit 32 for full-wave rectifying the standard sine wave voltage Vsin, and the input power voltage An offset value is added to the second full wave rectifying unit 34 for full-wave rectifying Vs) and the standard sine wave voltage Vsin (*) from the first full wave rectifying unit 32, and the power supply from the second full wave rectifying unit 34 is added. The offset value is added to the voltage Vs (*), and then the standard yarn to which the offset value is added A division circuit unit 40 which provides a result of dividing the pulsating voltage Vsin (*) + offset value by the power supply voltage Vs (*) + offset value to which the offset value is added to the integrator, and from the division circuit unit 40. Integrator 50 for integrating the provided value according to the set reset period and providing it to the comparator 60 and when the integral value is greater than the reference value by comparing the integral value provided from the integrator 50 with a preset reference value The comparator 60 outputs an instantaneous low voltage detection signal.

The offset value set by the division circuit unit 40 is for preventing the power supply voltage Vs (*) from being zero and dividing the standard sine wave voltage Vsin (*) by zero. 50 is configured to perform an integration after subtracting 1 from the value provided by the division circuit unit 40 so as to determine a more accurate low voltage amount by setting a reference value of zero to zero.

In addition, the comparator 60 is a reset signal set by the synchronization signal generator 10 is set to 1/4 cycle, 1/8 cycle, 1/16 cycle and 1/32 cycle with respect to the cycle of the input power voltage In this case, the instantaneous low voltage can be detected, and the synchronization signal generating unit 10 has a set reset signal cycle of 1/4 cycle, 1/8 cycle, 1/16 cycle, and 1 / of the cycle of the input power voltage. Can be set to one of 32 cycles.

FIG. 5 is a detailed view of the division circuit unit of FIG. 4. Referring to FIG. 5, the division circuit unit 40 includes a variable resistor VR1 configured to set an offset value and an offset value set by the variable resistor VR1. After addition to each input voltage, a division integrated circuit 45 is configured to perform division and output the result.

FIG. 6 is an output waveform diagram of FIG. 4, and FIG. 7 is a waveform showing an instant of occurrence of instantaneous low voltage. FIG. 8 is a histogram comparing the conventional low voltage detection speed with the detection speed according to the present invention.

Operation according to the device of the present invention configured as described above will be described in detail below based on the accompanying drawings.

Referring to FIG. 4 to FIG. 8, the instantaneous low voltage high speed detection device according to the present invention will be described. First, the synchronization signal generator 10 shown in FIG. 4 is configured to adjust the phase of the input power supply voltage Vs. After the detection, a square wave voltage Vp having the detected phase is generated and provided to the standard sine wave generation unit 20, and the zero-crossing of the input power supply voltage Vs is detected. The reset signal is provided to the integrator 50.

The standard sine wave generator 20 outputs a standard sine wave voltage Vsin based on the square wave voltage Vp provided from the synchronization signal generator 10. The input power supply voltage Vs and the standard sine wave voltage The waveform for Vsin is shown at the top of FIG.

The standard sine wave voltage (Vsin) is full-wave rectified in the first full-wave rectifier 32, and then provided to the division circuit unit 50, and the input power supply voltage (Vs) is full-wave rectified in the second full-wave rectifier (34) Next, the division circuit unit 40 is provided.

In the division circuit unit 40, an offset value set by the variable resistor VR1 for setting an offset value is added to the rectified power supply voltage Vs (*) and the rectified standard sine wave voltage Vsin (*), respectively. Divide the standard sine wave voltage (Vsin (*) + offset value) with the offset value divided by the power voltage (Vs (*) + offset value) with the offset value and divide the resultant value as shown in the middle of FIG. 50) to add an offset value before division to prevent the power supply voltage Vs (*) from being zero and dividing the standard sine wave voltage Vsin (*) by zero. The voltage error (Verr) due to the division is as shown in Equation (1).

As described above, the division circuit unit 40 makes the error voltage Verr constant with respect to a constant voltage drop width, and accordingly, the ratio of integration is constant regardless of the time point at which the voltage drop occurs.

The integrator 50 performs the integration while resetting the value provided from the division circuit unit 40 by the reset signal provided from the synchronization signal generator 10. The integrated result has an error of 1 as a reference. Since the error voltage is expressed as Equation 2, subtract 1 and then integrate.

According to Equation 2, the waveform output from the integrator 50 is shown at the bottom of FIG.

It can be seen that the output waveform of the integrator 50 shown in FIG. 6 is changing linearly. Therefore, in the present invention, even if the reset period is 1/8 cycle or 1/16 cycle of the use frequency, The instantaneous low voltage detection is possible even with only one reference voltage, so the response speed of the low voltage detector is faster than 1/8 cycle or less.

7 is a waveform showing the instant of the instantaneous low voltage generation, and FIG. 8 is a histogram comparing the conventional low voltage detection speed with the detection speed according to the present invention. ①, ②, ③, and ④ in FIG. 7 show the histogram in FIG. 8 by averaging the detection time of the instantaneous low voltage generated at each time point when the voltage drop rates are 20%, 30%, 40%, and 50%, respectively. Will be painted. For each voltage drop rate, (a) and (b) compare the prior art and the present invention with respect to a case where the reset period is a quarter period, and (c) and (d) have a reset period of 1 For the case of / 8 cycles, the present invention is compared with the conventional one. Comparing the above (a), (b), (c), (d), it can be seen that the detection speed according to the present invention is faster than the conventional one.

According to the present invention as described above, unlike the conventional detection device that can detect only 1/4 cycle, even if the reset period is 1/8 cycle or 1/16 cycle of the use frequency, even if there is only one reference voltage for detecting the instantaneous low voltage Since instantaneous low voltage detection is possible, there is a unique effect that the response speed of the low voltage detector is faster than 1/8 cycle or less.

The above description is only a description of one embodiment of the present invention, the present invention is capable of various changes and modifications within the scope of the configuration. In addition, those skilled in the art will readily appreciate that the instantaneous low voltage high speed detection device is not limited to the above described embodiment.

Claims (6)

The synchronization signal generator 10 outputs a square wave voltage Vp in synchronization with the phase of the input power supply voltage Vs and outputs a preset reset signal by a zero-crossing detection method for the input power supply voltage Vs. And a standard sine wave generator 20 for generating a standard sine wave voltage Vsin based on the square wave voltage Vp from the synchronization signal generator 10 and the standard sine wave voltage Vsin. A standard sine wave from the first full-wave rectifier 32 in the instantaneous low voltage detection device comprising a first full-wave rectifier 32 and a second full-wave rectifier 34 for full-wave rectifying the input power supply voltage Vs. A division circuit unit 40 which provides a resultant obtained by dividing the voltage Vsin (*) by the power supply voltage Vs (*) from the second full-wave rectifying unit 34 to the integrator; An integrator 50 for integrating the value provided from the division circuit unit 40 according to a set reset period and providing it to the comparator 60; A comparator (60) for comparing the integral value provided from the integrator (50) with a preset reference value and outputting an instantaneous low voltage detection signal when the integral value is larger than the reference value; Instantaneous low voltage high speed detection device comprising: a. The multiplier circuit 40 according to claim 1, wherein the division circuit unit 40 adds the variable resistor VR1 configured to set the offset value and the respective offset voltages set by the variable resistor VR1, and then divides the result. Instantaneous low voltage high speed detection device, characterized in that consisting of a division integrated circuit for outputting a result. 3. The divider circuit unit 40 according to claim 1 or 2, wherein the division circuit unit 40 adds an offset value to the standard sine wave voltage Vsin (*) from the first full-wave rectifying unit 32, and from the second full-wave rectifying unit 34. The offset value is added to the power supply voltage of Vs (*), and then the standard sine wave voltage (Vsin (*) + offset value) to which the offset value is added is divided by the power voltage (Vs (*) + offset value) to which the offset value is added. Instantaneous low voltage high speed detection device, characterized in that configured to provide a value to the integrator (50). 2. The instantaneous low voltage high speed detection apparatus according to claim 1, wherein the integrator (50) performs integration after subtracting 1 from a value provided from the division circuit unit (40). According to claim 1, wherein the comparator 60 is a reset signal set by the synchronization signal generator 10 is 1/4 cycle, 1/8 cycle, 1/16 cycle and 1/1 with respect to the cycle of the input power voltage The instantaneous low voltage high speed detection device characterized in that the instantaneous low voltage can be detected even when set to 32. According to claim 1 or 5, wherein the synchronization signal generation unit 10 has a set period of the reset signal is 1/4 cycle, 1/8 cycle, 1/16 cycle, 1/32 with respect to the cycle of the input power supply voltage Instantaneous low voltage high speed detection device, characterized in that set to one of the cycle.

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