JPH0322864A - Starting of power source device - Google Patents

Abstract

PURPOSE:To prevent the saturation of a choke coil upon starting by a method wherein a control circuit, obtaining the driving pulse of a switch, is added with a delay circuit, delaying a signal upon starting, while an error voltage is risen gradually up by the output of the delay circuit to effect the soft start of a boosting mode. CONSTITUTION:A starting signal A is inputted into an integral circuit, consisting of a resistor 23 and a capacitor 24 impressed with a negative voltage -Vcc at one terminal thereof, through a buffer 22 and is connected to the output of an error amplifier 12 through an impedance converting operational amplifier 25, a resistor 26 and a diode 27 while a delay circuit, grounded from the connecting point of the resistor 26 and the diode 27 through another didode 28, is added. Accordingly, the ' L' level of the output of a comparator 19 is continued for a long period of time after the input of the starting signal A while the voltage of the capacitor 24 is changed from -Vcc to OV. When the mode of operation is changed into transfer mode and the voltage of the capacitor 24 has exceeded OV, an error voltage Ver begins the increase thereof and the soft start of a boosting mode, having an absolute value Sa obtained by a multiplier 13, may be started.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a starting method K for a power supply device.More specifically, in a power supply device to which a nonlinear negative power source is connected, the AC input current during steady operation is It is concerned with approximating waves and improving their startup characteristics.

Conventional technology General IcSOAtl! i! A nonlinear load such as a power supply device is equipped with a TI power supply device that receives alternating current and obtains direct current, but such a power source 14lf! The AC input current at is in the form of a path with a rest period, so the input power factor
It was not 0%, and it was necessary to provide the power supply with a function to improve the input power factor.

As such a power supply device, a structure as shown in FIG. 5 has been proposed. This power supply device includes switches 4, 5, 6. 7 in Figure 6(b), <O) 9 (
d)? By controlling as shown in (6), the AC input current can be made into a positive wave shape as shown in Ii in Figure 6 (~), and if the bulk frequency filter consisting of Lo and Co is used to reduce the bird's frequency to a certain extent, the It is possible to create an ideal sine wave like Ia in Figure 6 (ω). In other words, when increasing the AC input current I1, turn on switches 4 and 5 or switches 6 and 7 to When increasing the duty of the mode in which energy is extracted (step-up mode) and decreasing the AC input current Ii, switch 4.7 or switches 5 and 6 are turned on to Capacitor 10N: All you have to do is increase the deity of the mode in which energy is transferred (h mode).By controlling ICtilJ in this way, the waveform shown in Figure 6 (■) can be obtained for the transformer 801st order II. .

Next, the constant voltage C of the DC output voltage vo1 of such a power supply device, that is, the voltage between the terminals of the capacitor 10 will be explained. The DC output voltage Vo is the resistor 11-1 shown in FIG.
．． 11-2 and 11-3, and the divided voltage is inputted to the inverting input terminal of the differential amplifier unit 120. On the other hand, the reference voltage Vref is input to the non-inverting input terminal of the front error multiplier 12, and the voltage is adjusted so as to obtain the error voltage Ver at the output.
There is. Further, the reference sine wave S converted into an absolute value {m by the absolute value circuit 14 and the above-mentioned difference voltage Ver are multiplied by a multiplier 15, . 4+′. The absolute value S of the reference sine wave is axed by tk&A in accordance with the v voltage Ver and is inputted to the No1/inverting input terminal of the comparator amplifier 15 as ~Sa. Furthermore, the AC input torque current 1 is inserted between the AC power supply 1 and the rectifier circuit 5, is detected by the current transformer 16, is converted into an absolute value by the counter value circuit 17, and then is incremented. radiator 18
The signal is amplified by the signal Ia and inputted to the inverting input terminal of the comparator amplifier 150 as Ia. The output F1 of this comparative axis increaser 15 is
The signal is input to the non-inverting input terminal of the comparator 19, compared with the sawtooth wave VΔ input to the inverting input terminal, and converted into a path waveform F2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . Note that when the output of the comparator 19 is at H level, the frequency dividing circuit 20 outputs a boost mode control signal, and when the output of the comparator 19 is at L repep, the frequency dividing circuit 20 outputs a boost mode control signal. It is configured to output a control signal for the 7th mode.

Further, the absolute value Sa of the width-modulated standard positive wave inputted to the non-inverting input terminal of the comparison amplifier 15 is determined by the Ulc equalizer 13 so that it becomes smaller as the DC output voltage vO becomes larger. However, if the DC output voltage vO becomes large, the comparison axis increaser 15
The output voltage F1 of the comparator 19 becomes smaller, and the pulse width of the output F2 of the comparator 19 becomes narrower. By holding in this way, the duty of the boost mode can be reduced and the DC output voltage vO can be lowered. Further, when the DC output voltage Vo becomes small, the DC output voltage vO can be increased by an operation opposite to the above operation, and constant voltage control of the DC output voltage vO is performed.

In the power source device as described above, since the capacitor 10 is in a discharged state at the time of startup, the M. The pressure is Ov. Therefore, the L level ρ of the output of the comparator 19 becomes the shortest state, and the boost mode in which the 7-switch 4.5 or the switch 6.7 is turned on is activated for a long time.

Problem II to be Solved by the Invention When the power supply is started while the C boost mode is long as described above, the capacitor 10 is in a discharged state, so
There were cases where a large current flowed through Kukoi/1/2 and saturated it. When Chisugaichi Kukoi Iv2 becomes saturated, there is a problem in that in boost mode, the power supply is short-circuited and Nuifuchi is destroyed.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention includes a circuit in which at least one switch is connected in series by inserting a single-circuit coil in parallel with the output of the rectifier circuit 6 that flows one alternating current into rfL contact flow. Connect the primary winding of the connected Tofunnu, and connect the Tofunnu to the Nuifuchi! I? An operating mode (boosting mode) in which the transformer is in an IFJ state is provided, and in this boosting mode, one energy is accumulated in the single coil in the stomach, and in an operating mode (transmission mode) in which the transformer is in an excitation state D, the accumulated energy is In the starting method of the power supply device, the secondary energy is transferred to the secondary circuit 1 of the transformer and the AC input current is made into a sine wave. Compare and increase the absolute value corresponding to the magnitude of the sine wave of the bogie by the difference between the DC output voltage obtained by rectifying the secondary output of the transistor. The control circuit includes a control circuit that compares the output of the switch with a sawtooth wave and obtains the drive bus of the swift via a frequency dividing circuit, and a delay circuit that delays the signal at startup is added to the control circuit. , the differential voltage is gradually raised by the output of this delay circuit to soft-start the boost mode.

By soft-starting the boost mode with the output of the delay circuit σ that delays the signal at the start of the operation, the current for charging the capacitor 10 in the discharged state is constant.
2, the current does not suddenly increase C,
Saturation of the power coil 2 can be prevented. That is, when the error voltage is gradually raised by the output voltage, the amplitude of the absolute amplitude of the reference sine wave can be gradually increased, so that the duty of the boost mode can be gradually increased.

Embodiment Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 1 & O. In FIG. 1, components having the same functions as those in the lpJS diagram are given the same reference numerals, and their main circuit portions are omitted. The difference between Fig. 1 and Fig. 5 is that the activation signal ▲ is
2 to an integrating circuit consisting of a resistor 23 and a capacitor 24 to which a negative voltage -VCC is applied to one end. This circuit is connected to the output of the quadrupler 12 and has a slow ta circuit connected to the connection point between the resistor 26 and the diode 27 and grounded via the diode 28. By doing this, the startup example A is input, and the voltage of the capacitor 24 becomes −”Jr3.
From 0 to Ov, the output Ver of the differential axis multiplier 12 is multiplied to Ov, so the L level of the output of the comparator 19 is the longest, and the &'R mode reaches 0, and the capacitor When the voltage of 24 or Ov is exceeded, ver starts to rise gradually, and the absolute value Sa of the gradient-modulated base sugar sine wave obtained by the voltage generator 13 is increased as the wave enters the voltage of voltage A. Soft start of the 7th wheel begins. That is, as shown in FIG. 5(b) to (6), switch 4.5
Alternatively, W4 can be used to gradually lengthen the on period of the switch 6.7. Here, Φ) ~ ( in Figure 3
f') corresponds to (b) to (g) in FIG.

FIG. 2 shows another embodiment of the present invention, in which the circuit of FIG. 1 is in the transmission mode while the output Ver of the error amplifier 12 is being scrambled to Ov, but since the capacitor 10 is in the discharge state, Even in the case of a transmission wire, there is a bulge that causes a large current to flow through I/I/2 and saturate it, which prevents this. That is, the starting multiplier A is connected to the resistor 50 via the buff 7a 29 and the capacitor 3 whose one end is grounded.
1, and its output is sent to a comparator 32.
A circuit is further added for inputting the sawtooth wave VΔ to the non-inverting input terminal of the comparator 52 and the output of the branch circuit B20 to the AND circuit 53. , amplify its output 21-1 to 21-4
The driving power of switches 4 to 7 is increased by ? I/S. By holding the precepts in this manner, the following actions are performed in parallel with the remembrance actions shown in FIG. That is, the start signal ▲ is input, and the capacitor 5
As the voltage of 1 gradually increases from Ov to A, the comparator 32
Since the period of the H level of the output becomes gradually longer, it is possible to obtain a drive pulse that gradually lengthens the on period of the switches 4, 7 or the switches 5, 6. Therefore, when the activation signal A is input, the output Ver of the error amplifier 12
is clamped to Ov, that is, when the L level of the output of the comparator 19 is the longest, the period of the H level of the output of the comparator 32 becomes progressively longer. The transfer mode can be soft-started as shown in ω}~(8) in Figure 4●Then, when the voltage of capacitor 24 exceeds Ov, sVf3r gradually rises and is width modulated as described above. The amplitude of the absolute MSa of the reference sine wave gradually increases, the L level period of the output of the comparator 19 gradually shortens by Ic, and a step-up mode starts. Here, (b) in Figure 4
-(f) correspond to (b)-(g) in FIG.

In the embodiment shown in FIG. 1, the step-up mode is soft-started at startup, so even if the startup is started while the capacitor 10 is discharged, the current flowing through the output coil 2 will suddenly increase and the output will continue to rise. It does not saturate N2. In addition, in the dormitory example shown in Figure 2, the transmission mode is soft-started prior to the soft start of the boost mode.
It is also possible to prevent saturation of the capacitor 2 due to the charging current of the capacitor 10 under the transfer mode.

Effects of the Invention As explained above, the starting method of the power supply device of the present invention is as follows.
It is possible to prevent the saturation of the current caused by the current at startup, and to prevent the switch from being destroyed due to this.

[Brief explanation of drawings]

Fig. 1 is a control circuit diagram for realizing the starting method of the present invention at +1% to 1%, Fig. 2 is a control circuit diagram of another embodiment of the present invention, and Fig. 3 is an explanatory diagram of the operation of Fig. 1. , Figure 4 is jl! FIG. 2 is an operation explanatory diagram, FIG. 5 is a circuit diagram for explaining the conventional starting method, and FIG. 6 is a waveform diagram of each part of the same.

Claims (2)

[Claims] (1) A choke coil is inserted in parallel with the output of a rectifier circuit that directly rectifies alternating current, and the primary winding of a transformer in which at least one switch is connected in series is connected, and the transformer is non-energized to the switch. In this step-up mode, energy is stored in the choke coil, and in an operation mode (transmission mode) in which the transformer is in an excited state, the stored energy is transferred to the secondary side of the transformer. In a starting method for a power supply device that converts an AC input current into a sinusoidal waveform, an AC input current detection means is provided, and an absolute value corresponding to the magnitude of the AC input current detected by the detection means is detected, and The DC output voltage obtained by rectifying the next-side output is compared with the absolute value of the reference sine wave amplitude-modulated by the error voltage, and the output is compared with the sawtooth wave and the output is It is equipped with a control circuit that obtains the drive pulses of the switch, and a delay circuit that delays the start-up signal is added to this control circuit, and the output of this delay circuit is used to gradually raise the error voltage and soft-start the boost mode. Characteristic power supply startup method. 2. The method for starting a power supply device according to claim 1, wherein the output of the delay circuit and the sawtooth wave are compared, and the transmission mode is soft-started until the error voltage rises.