KR100218087B1 - Voltage compensator using for alternative chopper - Google Patents

Abstract

The present invention relates to an instantaneous voltage compensator using an AC chopper to compensate for variations in the input power voltage in the industry to protect a sensitive load against unstable and disturbing power voltages. A voltage detector for detecting a voltage, a voltage controller for outputting a reference voltage by inputting a product of the voltage detected and output from the voltage detector and a differential amplifier gain, and a polarity signal of a voltage input to the input power supply terminal; An AC chopper switch controller for outputting a switching function signal of an AC chopper switch by inputting a polarity detector, a reference voltage input from the voltage controller and a polarity signal detected by the polar detector, and switching of the AC chopper switch controller Consisting of a switching driving circuit which switches by a function signal It features.

Description

Instantaneous voltage compensator using AC chopper

The present invention relates to an instantaneous voltage compensator using an AC chopper, and more particularly, to an instantaneous voltage compensator using an AC chopper that compensates for variations in the input power voltage in an industry to protect a sensitive load against an unstable and disturbing power supply voltage. It is about.

In general, the ideal power source used in the industry is a sinusoidal wave with a frequency of 60 kHz and a constant magnitude and containing no harmonic content.

In practice, however, the disturbance causes fluctuations in the power supply voltage that rise or fall for several cycles.

Due to this change in power supply voltage, power-sensitive devices such as computers, communication equipment, and process control systems have caused serious problems such as data loss, communication service interruption, and long production line interruption.

Therefore, an instantaneous voltage compensator capable of quickly compensating for the fluctuation of the power supply voltage is required.

However, the most commonly used instantaneous voltage compensator is a phase-controlled AC controller using a thyristor. The thyristor has the advantage of being suitable for high reliability and large capacity, whereas the instantaneous voltage compensator has a slow response, low power factor, and high current. In order to reduce the generated harmonics and harmonics of the output voltage, a large input / output filter is required.

Therefore, in order to overcome the above disadvantages, the pulse width modulation scheme has been adapted to the AC chopper.

However, the conventional AC chopper using the pulse width modulation method has only one output of the phase voltage, in phase or inverse phase of the input voltage, so it is difficult to properly compensate for both the increase or decrease of the supply voltage.

An object of the present invention is to enable the control of both the phase and in phase or reverse phase of the input voltage to easily compensate for variations in the power supply voltage, to protect the sensitive load from the unstable and disturbing input power supply voltage It is.

In order to achieve the above object, the present invention provides a voltage detector for detecting a voltage output to an input power supply terminal, and a voltage for outputting a reference voltage by inputting a product that is a square of the voltage detected by the voltage detector and the differential amplifier gain. A switching function signal of the AC chopper switch by inputting a controller, a polarity detector for detecting a polarity signal of a voltage input to the input power supply terminal, a reference voltage input from the voltage controller and a polarity signal detected by the polarity detector It is characterized by consisting of an AC chopper switch controller for outputting a switching drive circuit for switching the drive by the switching function signal of the AC chopper switch controller.

1 is an overall circuit diagram of an instantaneous voltage compensator using the AC chopper of the present invention.

2 is a circuit diagram of a voltage detector of an instantaneous voltage compensator applied to the present invention.

3 is a controller circuit diagram of an instantaneous voltage compensator applied to the present invention.

4 is an output waveform diagram of a controller of an instantaneous voltage compensator applied to the present invention.

* Explanation of symbols for main parts of the drawings

100: voltage detector 110: voltage controller

120: polarity detector 130: AC chopper switch controller

140: switching drive circuit

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

1 is an overall circuit diagram of an instantaneous voltage compensator using the AC chopper of the present invention, a voltage detector 100 detecting a voltage output to an input power supply terminal Va, and a voltage detected and output from the voltage detector 100. And a voltage controller 110 for outputting a reference voltage by inputting a product that is a square of gain of a differential amplifier, a polarity detector 120 for detecting a polarity signal of a voltage input to the input power terminal Va, and the voltage controller ( AC chopper switch controller 130 for outputting a switching function signal of the AC chopper switch by inputting a reference voltage input from 110 and the polarity signal detected by the polarity detector 120, and the AC chopper switch controller 130 Cone to reduce conduction and cancellation of switching elements (GT01-GT08), filters (Lo, Co), AC choppers (L), and current harmonics, in which the reverse diodes connected in parallel are switched by a switching function signal The instantaneous safety compensator compensates through the AC chopper L when the output voltage Vo changes, and compensates the compensating voltage Vc. Is added in series with the input power supply voltage Va so that the output voltage Vo is always a constant voltage even in a moment of disturbance.

2 is a circuit diagram of a safety detector of an instantaneous voltage compensator according to the present invention, and a differential amplifier 101 for outputting a κ s Vo cos wt voltage having a gain κs with respect to an output voltage Vo and a differential amplifier 101. Phase shifter 102 outputting κ s Vo sin wt voltage by 90 ° phase shift with respect to the output κ s Vo cos wt voltage, κ s Vo cos wt output from the phase shifter 102 and the differential amplifier 101 The multipliers 103 and 104 respectively multiply the kS Vo cos wt output from the multiplier and the summator 105 for summing the squared voltages of the multipliers 103 and 104, respectively.

FIG. 3 is a controller circuit diagram of an instantaneous voltage compensator applied to the present invention. The AC chopper switch is switched by inputting the output V _ref of the voltage controller 120 and the polarity signal S of the input power voltage Vs that is the output of the polarity detector 110. The AC chopper switch controller 130 for outputting a function includes a voltage inverter 131 for inverting the output V _ref of the voltage controller 120, a triangle wave generator 132 for generating a predetermined triangle wave, and the voltage inverter A first comparator 133 for comparing a voltage inverted at 131 with a triangle wave generated by the triangle wave generator 132 and outputting a predetermined comparison voltage, and a voltage and triangle wave generator inverted at the voltage inverter 131. Insulation time is calculated by calculating a predetermined comparison voltage between the second comparator 134 and the first comparator 133 and the second comparator 134 to output a predetermined comparison voltage by comparing the triangle wave generated at 132. outputting a signal with a dead time It is to be composed of a collector portion 135 and the open collector 135 signal and the polarity detector 110, programmable logic array (136) for outputting a switching function to the signal (S) outputted from the output from.

4 is an output waveform diagram of the controller of the instantaneous voltage compensator applied to the present invention, and outputs the process of compensating and outputting the voltage through the controller 130 of the instantaneous voltage compensator with respect to the output power voltage Vo of the AC chopper. It is a waveform diagram.

Referring to the effects of the present invention configured as described above are as follows.

The output voltage Vo input from the input power terminal Va is detected by the voltage detector 100 using the trigonometric formula, and the output voltage Vo is referred to as Vo cos wt. In this case, the differential amplifier 101 differentially amplifies the gain κs and outputs κ s Vo cos wt. The output is phase shifted 90 ° through the phase shifter 102 to output κ s Vo sin wt. At this time, the differential amplification voltage κs Vo cos wt and the phase shifted voltage κs Vo sin wt are squared through the multipliers 103 and 104, respectively, and then summed through the summer 105. The trigonometric equation κs2 Vo2 cos2 Wt + κs2 Vo2 sin2 Wt = κs ² Vo ² is satisfied.

Therefore, the output Vos of the voltage detector 100 is multiplied by the square Vo2 of the output voltage magnitude and the gain of the differential amplifier 101 by the square κs2.

The output Vos of the voltage detector 100 is input to the voltage controller 110, and thus, in the voltage controller 110, the difference of vos which is the product of the square of the magnitude of the output voltage to be controlled (Vr) and the square of the differential amplifier gain. Inputs the reference voltage V _ref to the AC chopper switch controller 130 to output the voltage Vc to be compensated by the AC chopper, and the AC chopper switch controller 130 may be configured as the voltage controller 110. V _ref and the output signal S to the polarity of an output, the input power source voltage Vs of the polarity detector 120 as an input AC chopper switch eight switching function ^{(Y 1, Y 2, ...} Y 8) is an output.

That is, the AC chopper switch controller 130 conducts the corresponding switch when the switching function value is 1, and when the switching function is 0, the switch is erased.

In other words, the AC chopper switch controller 130 outputs the output -Vref and the triangular wave generator inverting Vref, the input of the voltage controller 110 through the voltage inverter 131, in order to use the pulse width modulation method having unipolar voltage switching. 132 and the triangular wave Vtri generated by comparing the size of the comparator 133, 134, and outputs U and create a ₁ and U _2, the comparator 133, 134, the output of U ₁ and U ₂ is the Output signals A, B, C, and D used to make dead time using TTL 7406 having an output through the open collector unit 135, and the output signals A, B, C, and D are programmed. The input is made to the available logic array 136.

Therefore, the programmable logic array 136 inputs the output signals A, B, C, and D of the open collector unit 135 and the output signal S of the polarity detector 120 to form a switching function to form a switching drive circuit 140. The switching function signals Y ₁ -Y ₈ for switching the switching elements GT01-GT08 of the N th output are output.

At this time, the switching function by the programmable logic array 136 is as follows.

Y ₁ = S

Y ₂ = S '

Y ₃ = S '

Y ₄ = S

Y ₅ = A o S + C o S '

Y _B = A o S + D o S '

Y ₇ = A o S '+ C o S

Y ₈ = B o S '+ D o S

Where 'is NOT gate, o is AND gate, and + is OR gate)

Therefore, when the output voltage Vo of the AC chopper is given the AC voltage waveform as shown in FIG. 4 and the _first , S ₁ , S ₂ , S ₃ , and S ₄ output from the AC chopper switch controller 130 are equal to the _second in FIG. 4. According to the switching functions Y ₁ , Y ₂ , Y ₃ , and Y ₄ , the inverted voltage waveforms are outputted.

Therefore, the voltage Vde between d and e of the switching driving circuit 140 outputs the voltage waveform as shown in FIG. 4 and the fourth output waveform of FIG. The output voltage V _ref and -V _ref of 131 and the triangle wave Vtri of the triangular wave generator 132 are compared with the output waveforms showing the output values of the switching functions Y ₅ and Y ₇ .

On the other hand, the fifth voltage waveform of FIG. 4 represents the output voltage vfg between f and g of the switching driver circuit 140.

The output voltage vfg of the switching driver circuit 140 is filtered by the filters Lo and Co as output terminals so that the output voltage Vc compensated as shown in FIG. 4 is output.

In general application of AC voltage source, capacitor (Ct) is used to make more ideal voltage source and to mitigate current harmonics in load because it has the same inductance component rather than ideal voltage source (internal impedance is 0).

As described above, the present invention detects a voltage inputted to and outputted from an input power supply terminal used in industry, outputs a reference voltage from the detected voltage, and compares the reference voltage and the voltage inputted to the input power supply terminal. Outputs the switching function signal through the AC chopper switch controller by inputting the polarity signal which detected the polarity signal, and drives the switching drive circuit with this switching function signal to compensate for the voltage at the output end of the AC chopper at the output end. This provides the effect of protecting sensitive loads from many input supply voltages.

Claims (3)

Voltage controller 100 for detecting the voltage output to the input power terminal (Va) and a voltage controller for inputting a product that is the square of the voltage and differential amplifier gain detected and output from the voltage detector 100 to output a reference voltage A polarity detector 120 for detecting a polarity signal of a voltage input to the input power terminal Va, a reference voltage input from the voltage controller 110, and a polarity detector 120; AC chopper switch controller 130 for outputting the switching function signal of the AC chopper switch and the reverse diode for switching driving are connected in parallel by the switching function signal of the AC chopper switch controller 130. It is composed of a switching drive circuit 140 composed of a switching element (GT01-GT08), a filter (Lo, Co), an AC chopper (L), and a condenser (C1) to mitigate current harmonics are conducted and eliminated.It is the instantaneous voltage compensator using an AC chopper. The voltage detector (100) of claim 1, wherein the voltage detector (100) outputs a κ s Vo cos wt voltage having a gain κs with respect to the output voltage Vo and a κs Vo output from the differential amplifier 101. Phase shifter 102 outputting κ s Vo sin wt voltage by 90 ° phase shift with respect to cos wt voltage, κ s Vo sin wt output from the phase shifter 102 and output from the differential amplifier 101 AC alternator comprising a multiplier (103) (104) for multiplying ks Vo cos wt and a summer (105) for summing the squared voltages in the multiplier (103) (104). Instantaneous voltage compensator. The AC chopper switch controller 130 outputs a switching function of the AC chopper switch by inputting the output signal Vref of the voltage controller 120 and the polarity signal S of the input power supply voltage Vs that is the output of the polarity detector 110. The AC chopper switch controller 130 includes a voltage inverter 131 for inverting the output Vref of the voltage controller 120, a triangle wave generator 132 for generating a predetermined triangle wave, and the voltage inverter 131. The first comparator 133 compares the inverted voltage with the triangular wave generated by the triangular wave generator 132 and outputs a predetermined comparison voltage, and the voltage inverted by the voltage inverter 131 and the triangular wave generator 132. The second comparator 134 which compares the generated triangular wave and outputs a predetermined comparison voltage, and calculates a predetermined comparison voltage of the first comparator 133 and the second comparator 134 to insulate a dead time. An open collector unit 135 for outputting a signal having the Instantaneous using an AC chopper, characterized in that consisting of a programmable logic array 136 for outputting a switching function to the signal output from the open collector unit 135 and the signal (S) output from the polarity detector (110). Voltage compensator.

Images