JPH062469Y2 - Phase control device - Google Patents

Description

[Detailed Description of the Invention] (Technical Field of the Invention) The present invention is directed to a phase control device, in particular, to a case where the AC frequency fluctuates greatly, for example, an AC voltage generated by engine rotation of a ship causes a large frequency fluctuation. Regardless, the present invention relates to a phase control device of a DC constant voltage device using a thyristor that obtains a constant DC voltage from the AC voltage.

(Background and problems of the invention) The frequency of the AC voltage used in ships varies greatly depending on the traveling speed of the ship. Conventionally, the DC voltage regulator using a thyristor mounted on a ship uses the phase controller shown in FIG. That is, reference numeral 1 in FIG. 4 denotes a control voltage generation circuit, and the inverting input terminal of the operational amplifier 3 provided in the control voltage generation circuit 1 is connected to the DC output shown in FIG. Part of the voltage is input as a negative voltage. In addition, the operational amplifier 3
The reference voltage is applied to the non-inverting input terminal of the
The output of the control voltage generation circuit 1, that is, the threshold voltage e _t changes according to the fluctuation of the DC output voltage shown in the figure. Reference numeral 2 is a phase control pulse generating circuit, and the threshold voltage _et is input as a reference voltage via a resistor 6 to an inverting input terminal of an operational amplifier 5 which constitutes a comparator. The lamp voltage shown in FIG. 5 (III) is input to the non-inverting input terminal via the resistor 7. The output of the control voltage generating circuit 2 is the gate signal of the thyristors 10, 13 or 11, 12 shown in FIG.

FIGS. 5 (I) to (III) show a waveform processing process for obtaining a lamp voltage from an AC voltage, and FIG. 5 (I) uses an AC input applied to the thyristors 10 to 13 in FIG. is doing. Then, the AC input waveform is shaped every other half wave to obtain the rectangular wave shown in FIG. 11B, and the ramp voltage shown in FIG. This ramp voltage is input to the phase control pulse generating circuit 2 as described above.

Now, the DC constant voltage device composed of the thyristors 10 to 13, the choke coil 14 and the capacitor 15 shown in FIG. 7 has no fluctuation (especially frequency) on the AC voltage side, and is based on some cause. For example, when the DC output voltage drops, the threshold voltage of the control voltage generating circuit 1 also drops as shown by the alternate long and short dash line in FIG. On the other hand, since the AC voltage of the ramp voltage input to the phase control pulse generation circuit 2 is unchanged, the generation timing of the phase control pulse output from the phase control pulse generation circuit 2 is as shown in FIG. Get wider That is, the thyristor 10 shown in FIG.
The timing of igniting 13 or 11, 12 is advanced from T ₀ to T ₁ shown in FIG. 6, and the DC output voltage works so as to increase, and the DC voltage regulator holds the constant voltage.

However, since the AC generator mounted on the ship utilizes the rotation of the engine that drives the screw, the frequency of the generated AC voltage fluctuates greatly depending on the traveling speed of the ship. Considering the conduction period of the thyristor in each of the AC voltage when the engine is rotating at an economical speed and the AC voltage when the engine is rotating at a high speed and the frequency is high, the phase control pulse generating circuit 2 lamp voltage is a predetermined voltage to be input to, i.e. the ratio of the phase control pulse for conducting the thyristor from when it reaches the threshold voltage e _t output from the control voltage generating circuit 1 is occupying in half-wave of the alternating voltage , The turn-on time from when the phase control pulse is applied to the gate of the thyristor to when the thyristor actually conducts is always constant, regardless of the frequency of the AC voltage. The higher the ratio, the smaller the proportion of conduction time in the AC half-wave. On the contrary, when the frequency of the AC voltage is low, the proportion of the conduction time in the AC half wave becomes large. Therefore, the DC voltage regulator using the conventional phase control device has the characteristics shown by the alternate long and short dash line in FIG. 3, and is not suitable for the DC voltage regulator of a ship in which the engine speed fluctuates significantly,
It had the drawback that it could not be used to charge the DC voltage equipment of ships, especially batteries.

(Object and Structure of the Invention) The present invention aims to solve the above-mentioned drawbacks.
It is an object of the present invention to provide a phase control device that can always obtain a constant DC output voltage regardless of fluctuations in the frequency of an AC voltage input to a rectifier circuit using a thyristor. Therefore, the phase control device of the present invention is provided with a control voltage generating circuit for generating a threshold voltage proportional to the DC output voltage by applying a DC output voltage in which a given AC voltage is exchanged, and a waveform of the AC voltage. A phase control pulse generating circuit for controlling the firing angle of the thyristor from the lamp voltage obtained from the above and the threshold voltage, and a DC constant for converting the AC voltage into the DC output voltage by the phase control of the thyristor. A phase control device in a voltage device is provided with a threshold voltage correction circuit having an amplifier to which the lamp voltage itself is applied, a diode for rectifying the output of the amplifier, and a capacitor for smoothing the output from the diode. At the same time, the correction voltage obtained by the threshold voltage correction circuit is superimposed on the DC output voltage to generate the control voltage. The threshold voltage from the threshold voltage correction circuit, which is supplied to the raw circuit and corrected by the correction voltage, is supplied to the phase control pulse generating circuit. Regardless of the above, the feature is that the above DC voltage is made constant. Hereinafter, description will be given with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of a phase control device according to the present invention, FIG. 2 is an explanatory view of a waveform of a correction voltage obtained based on a lamp voltage, and FIG. 3 is a phase control device according to the present invention. The characteristic curve figure which compared the frequency characteristic of the direct current constant voltage device and the direct current constant voltage device which used the conventional phase control apparatus is shown.

In FIG. 1, reference numerals 1 to 9 correspond to those of FIG. 4 already described, and a threshold voltage correction circuit of reference numeral 16 is newly added to the conventional phase control device. The threshold voltage correction circuit 16 includes an operational amplifier 17 forming a voltage follower circuit, an operational amplifier 18 forming an amplifying circuit together with resistors 22 and 23, a diode 19, and a capacitor 2.
0, resistors 21 and 24 are provided. Then, the ramp voltage input to the phase control pulse generating circuit 2 is input to the non-inverting input terminal of the operational amplifier 17 which constitutes the voltage follower circuit. The voltage follower circuit having a high input impedance inputs the lamp voltage to the threshold voltage correction circuit 16 so that the conventional phase control pulse generation circuit 2 is not affected. The output of the operational amplifier 18, whose amplification degree is determined by the ratio of the resistance values of the resistors 23 and 22, is connected to the inverting input terminal of the operational amplifier 3 in the control voltage generation circuit 1 via the resistor 24. The feedback voltage of the DC output voltage shown in FIG. 7 input to the inverting input terminal and the correction voltage from the threshold voltage correction circuit 16 are added by the operational amplifier 3. Along with this, the non-inverting input terminal of the operational amplifier 3 is grounded.

The ramp voltage input to the operational amplifier 17 in the threshold voltage correction circuit 16 charges the capacitor 20 via the resistor 21 and the diode 19 without being amplified. The voltage of the capacitor 20, that is, the voltage at the point A is held near the beak value of the ramp voltage waveform. Therefore, when the frequency of the AC voltage is high, the peak of the lamp voltage waveform is low, and when the frequency of the AC voltage is low, the peak of the lamp voltage waveform is high. Therefore, the voltage waveform at point A is the second peak when the frequency of the AC voltage is high. As shown in FIG. 2 (I), when the frequency of the AC voltage is low, it becomes as shown in FIG. 2 (II). These voltage waveforms are appropriately amplified by the operational amplifier 18 and input as a correction voltage to the control voltage generation circuit 1 via the resistor 24. The control voltage generation circuit 1
Since a negative DC output voltage with respect to the ground potential is fed back to, the correction voltage from the threshold voltage correction circuit 16 increases and the output from the control voltage generation circuit 1 increases, for example, when the frequency of the AC voltage increases. The threshold voltage applied is low. Therefore, as in the case described with reference to FIG. 5, the threshold voltage decreases as shown by the dashed line in the figure, and the timing of firing the thyristors 10, 13 or 11, 12 shown in FIG. The phase control circuit controls the rectifier circuit using the thyristors 10 to 13 so as to operate so as to increase the output voltage and compensate for the drop in the DC output voltage caused by the increase in the frequency of the AC voltage. On the contrary, when the frequency of the AC voltage is low, the correction voltage from the threshold voltage correction circuit 16 is low and the threshold voltage output from the control voltage generation circuit 1 is high. As a result, the thyristor 10, 13 or 1 shown in FIG.
It operates so that the timing of firing 1 and 12 is delayed and the DC output voltage is lowered. Therefore, the increase in the DC output voltage due to the decrease in the frequency of the AC voltage is compensated.

In this way, the correction voltage output from the threshold voltage correction circuit 16 changes the threshold voltage input to the phase control pulse generation circuit 2 in response to the fluctuation of the frequency of the AC voltage. The DC output voltage is always constant even if the frequency of the AC voltage fluctuates. When the frequency of the AC voltage is constant, the correction voltage from the threshold voltage correction circuit 16 is constant, but the control voltage is adjusted according to the amount of feedback fluctuation of the DC output voltage input to the control voltage generation circuit 1. Since the threshold voltage output from the voltage generating circuit 1 also naturally changes, the DC output voltage is kept constant as described above.

(Effect of the Invention) As described above, according to the present invention, since the threshold voltage correction circuit that shifts the ignition timing of the thyristor according to the frequency fluctuation of the AC voltage is provided, the engine speed fluctuates greatly. It can be used for a DC voltage regulator of a ship.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of a phase control device according to the present invention, FIG. 2 is an explanatory view of a waveform of a correction voltage obtained based on a lamp voltage, and FIG. 3 is a phase control device according to the present invention. Characteristic curve diagram comparing frequency characteristics of a DC constant voltage device and a DC constant voltage device using a conventional phase controller, 4th
FIG. 5 is a circuit configuration of a conventional phase control device, FIG. 5 is a waveform explanatory view explaining a waveform processing process of an AC input voltage, and FIG. 6 is a firing timing explaining a change in firing timing of a thyristor. FIG. 7 is a DC voltage conversion circuit diagram using a thyristor. In the figure, 1 is a control voltage generation circuit, 2 is a phase control pulse generation circuit, 3, 5, 17, 18 are operational amplifiers, 4, 6 to 8, 21 to 24 are resistors, 9, 15, 20 are capacitors, 10 Reference numerals 13 to 13 are thyristors, 14 is a choke coil, 16 is a threshold voltage correction circuit, and 19 is a diode.

Claims (1)

[Scope of utility model registration request] 1. A control voltage generating circuit for applying a DC output voltage obtained by converting a given AC voltage to generate a threshold voltage proportional to the DC output voltage, and a control voltage generating circuit obtained from the waveform of the AC voltage. A phase control pulse generating circuit for controlling the firing angle of the thyristor from the lamp voltage and the threshold voltage, and a phase in a DC voltage regulator for converting the AC voltage to the DC output voltage by the phase control of the thyristor. The control device is provided with a threshold voltage correction circuit having an amplifier to which the lamp voltage itself is applied, a diode for rectifying the output of the amplifier, and a capacitor for smoothing the output from the diode. The correction voltage obtained by the threshold voltage correction circuit is superimposed on the DC output voltage and supplied to the control voltage generation circuit. The threshold voltage corrected by the correction voltage from the threshold voltage correction circuit is supplied to the phase control pulse generation circuit, and the DC voltage is fixed regardless of the fluctuation of the frequency of the AC voltage. A phase control device characterized in that it is adapted to a voltage.