JPH08308223A - Dc power source - Google Patents

Abstract

PURPOSE: To simplify the structure of a DC power source circuit and the entire DC power source by externally forming a synchronizing signal generator for synchronizing a voltage control circuit which is not satisfactorily functioned with a switching operation in a plurality of the DC power source circuits connected in parallel as one circuit. CONSTITUTION: A voltage control circuit 11 detects the mean value of the output voltages from DC power source circuits at the input stage of a load unit 18, and transmits how to deviate from the set value of the output voltage to a pulse width setter 19. The output of the setter 19 is transmitted to each DC power source circuit including a DC power source circuit by a transmitter 20. The receiver 22 in each DC power source circuit returns the received signal to a clear rectangular wave, and transmits it to a pulse width control circuit 25. The circuit 25 transmits the signal having the same width as the signal from the receiver 22, but if the current value detected by a current control circuit 10 exceeds a predetermined current value, it instantaneously turns off the pulse signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply device configured to supply power by connecting a plurality of current control type DC power supply circuits in parallel to a load device requiring a large current. The present invention relates to a high-performance high-performance DC power supply device for high power, which synchronizes the switching operation of the DC power supply circuit to prevent each DC power supply circuit from being disturbed and has a voltage control circuit in each DC power supply circuit to individually perform voltage control. It is a thing.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional DC power supply device. In FIG. 6, 1 is a primary power supply, 2 is a relay circuit, and 3 is a power supply.
Is an input capacitor, 4 is a transformer for power conversion, 5 is a switching transistor, 6 is a drive circuit for driving the transistor 5, 7 is a rectifying diode, 8 is a smoothing choke coil, 9 is an output capacitor, and 10 is A current control circuit for controlling the output current, 11 is a voltage control circuit for controlling the voltage at the output stage of the DC power supply circuit, and 12 is the output of the current limiting circuit 10 and the voltage control circuit 11, and has a switching pulse width. Pulse width control circuit to determine, 1
Reference numeral 3 is a relay drive circuit that receives the output of the pulse width control circuit 12 and turns off the input relay circuit when the DC power supply circuit becomes abnormal. Reference numeral 14 is for synchronizing the switching operation of the transistor 5 with a synchronization signal from the outside. Synchronous circuit, 1
Reference numeral 5 is a first DC power supply circuit composed of each circuit of 2 to 14, 16 is a second DC power supply circuit composed of the same circuit as the first DC power supply circuit 15, and 17 is a switching operation of each DC power supply circuit. Signal generation circuit for synchronizing signals, 18
Is a load device.

Next, the operation of the conventional device shown in FIG. 6 will be described. The DC power supply circuit 15 shown in FIG. 6 is a current-controlled switching power supply that is the mainstream in a system that supplies power by connecting a plurality of DC power supply circuits in parallel. For convenience of explanation, the operation will be described with two DC power supply circuits. The operation is such that the transistor 5 is turned on / off and a pulse current is passed through the primary side of the transformer 4, thereby transmitting power to the secondary side of the transformer 4 and rectifying the power generated on the secondary side of the transformer 4. After being rectified by the diode 7, the output capacitor 9 is passed through the choke coil 8.
The electric charge is stored in and is supplied to the charge device 18 as a predetermined DC voltage. The voltage control circuit 11 detects the voltage across the capacitor 9 and sends a signal to the pulse width control circuit 12 to widen the ON width of the transistor 5 when the voltage drops and narrow the ON width when the voltage rises. On the other hand, the current control circuit 1
0 detects the output current of the choke coil 8 and sends a signal to the pulse width control circuit 12 so as to narrow the ON width of the transistor 5 when the current exceeds a predetermined value. The pulse width control circuit 12 determines the ON width of the transistor 5 based on the signals from the current control circuit 10 and the voltage control circuit 11, and sends a drive signal to the transistor drive circuit 6. Thereby, the on / off ratio of the switching of the transistor 5 is
It is controlled by both the output voltage and the output current, and operates so as to keep the voltage across the capacitor 9 constant while limiting the maximum output current. The synchronizing circuit 14 receives the signal from the synchronizing signal generating circuit 17, and determines the timing of turning on or off the transistor 5 in the second DC power supply circuit 1.
6, so that the DC power supply circuit does not interfere with each other due to interference with each other. Therefore, a plurality of similar DC power supply circuits can be connected in parallel, and each is controlled so as not to flow a current higher than the rated current, so that it is possible to supply electric power that is twice the rated electric power.

Therefore, when a plurality of DC power supply circuits are connected in parallel and used, the output current of each DC power supply circuit is controlled by an individual current control circuit, so that each DC power supply circuit is almost the same. The output current of can be output. However, the control by voltage detects the voltage at each power supply output terminal and sets the switching on-pulse width from the detected voltage value.However, since multiple DC power supply circuits are connected in parallel, The output voltage of each DC power supply circuit is not detected, but only the average voltage value is detected, and even if there is some error in the output voltage value of each DC power supply circuit, all DC power supply circuits The same voltage value was detected, and only the same pulse width could be converted.

[0005]

Since the conventional DC power supply device is configured as described above, even if each DC power supply circuit has a voltage control circuit, it can be controlled by each output voltage value. Not all of them have the same pulse width with the same voltage value, so most of the voltage control circuits in each DC power supply circuit are not functioning correctly and the There was a problem that utilization efficiency was poor. In addition, since there are subtle variations in the voltage of each DC power supply circuit, the stress applied to each DC power supply circuit will not be uniform,
There was a problem that the life of only some DC power supply circuits was shortened.

The present invention has been made to solve the above problems, and a synchronizing signal generation for synchronizing a switching operation with a voltage control circuit which does not function satisfactorily in each DC power supply circuit. By externally configuring the circuit as one circuit and omitting the voltage control circuit and the synchronizing circuit from each DC power supply circuit, the configuration of the DC power supply circuit and the entire DC power supply device are simplified, and each DC power supply circuit is individually configured. It is an object of the present invention to configure the entire device so that a switching operation can be performed in consideration of an error of a circuit that the device has and a stress applied to each DC power supply device can be equalized.

[0007]

A DC power supply device according to a first embodiment of the present invention is a pulse width setting for setting a pulse width from one of voltage control circuits existing in each DC power supply circuit and a voltage control signal. It is equipped with a voltage control signal generation circuit consisting of a circuit and a transmission circuit, detects the voltage at the input stage of the load device, and sets the switching pulse-on width with the voltage control signal generation circuit so that the detected voltage becomes a predetermined voltage. , Each DC power supply circuit determines the ON width of switching from the voltage control signal sent from the voltage control signal generation circuit and the current control signal in each DC power supply device, and synchronizes with the signal from the voltage control signal generation circuit. Then, the switching operation is performed.

The DC power supply device according to the second embodiment of the present invention is provided with a pulse number modulation circuit (hereinafter referred to as PNM modulation circuit) in the voltage control signal generation circuit, and the pulse set from the voltage value of the load device input stage is set. The width signal is pulse-number modulated (hereinafter referred to as PNM modulation) and transmitted to each DC power supply circuit together with the clock signal, and the pulse number signal (hereinafter referred to as PNM signal) is demodulated into a pulse width signal in each DC power supply circuit to obtain the pulse width. The control is performed and the switching operation is performed in synchronization with the clock signal from the voltage control signal generation circuit.

Further, the DC power supply device according to the third embodiment of the present invention is provided with a data correction circuit for correcting the PNM signal in each DC power supply circuit, and in each DC power supply circuit before demodulating the PNM signal. It corrects the error of the output voltage value of each DC power supply circuit due to the error of the transformer performance and the subtle error of the input voltage, etc., and performs the switching operation so that the output voltage of each DC power supply circuit becomes the same. .

[0010]

According to the DC power supply device of the first embodiment of the present invention, only one circuit is required for the voltage control circuit in the voltage control signal generating circuit. The synchronous circuit can be omitted and the synchronous signal generating circuit can be omitted, so that the entire DC power supply device can be simplified and the cost can be reduced.

Further, according to the DC power supply device of the second embodiment of the present invention, when the number of DC power supply circuits connected in parallel is very large, or between the DC power supply circuits or between the voltage control signal generating circuits. Realizes a highly reliable DC power supply device that can accurately transmit signals even if the DC power supply circuit is far away from the DC power supply circuit and that the switching pulse width does not change due to the influence of noise. be able to.

Further, according to the DC power supply device of the third embodiment of the present invention, even if there are some variations in the transformer characteristics or the input voltage of each DC power supply circuit connected in parallel, the variations may occur. By correcting the switching pulse-on width in accordance with the above, the output voltage of each DC power supply circuit can be made the same, and the stress applied to each DC power supply circuit can be equalized, realizing a more reliable DC power supply device. be able to.

[0013]

【Example】

Example 1. FIG. 1 is a circuit configuration diagram showing a first embodiment of the present invention. In the figure, 1 to 18 are the same as the above-mentioned conventional devices and circuits, and 19 is a pulse width of switching from a signal from a voltage control circuit 11. A pulse width setting circuit for setting the pulse width setting circuit 20, a transmitting circuit for transmitting the output of the pulse width setting circuit 19 to each DC power supply circuit, and 21 for 11, 19, 2
A voltage control signal generating circuit composed of the circuit shown in FIG.
Is a receiving circuit for receiving the pulse width signal from the transmitting circuit 20.

The operation will be described in detail below with reference to the drawings. In the configuration as shown in FIG. 1, the voltage control circuit 11 detects the average value of the output voltage from each DC power supply circuit at the input stage of the load device 18, and determines how much the output voltage is deviated from the set value. It is transmitted to the width setting circuit 19. The pulse width setting circuit 19 receives the signal from the voltage control circuit 11, and if the output voltage is lower than the set value, the pulse width setting circuit 19 widens the pulse width from the current value for a time corresponding to the difference between the output voltage value and the set value, and the output voltage is set to the set value. If it is higher, the pulse width is made narrower than the current one for the time corresponding to the difference between the output voltage value and the set value. The output of the pulse width setting circuit 19 is transmitted by the transmission circuit 20 to each DC power supply circuit including the DC power supply circuit 15. The reception circuit 22 in each DC power supply circuit returns the received signal to a clean rectangular wave and sends it to the pulse width control circuit 25. The pulse width control circuit 25 transmits a signal having the same pulse width as the signal from the reception circuit 22 to the drive circuit 6, but the current control circuit 1
When the current value detected by 0 exceeds a predetermined current value, the pulse signal is instantly turned off. Therefore, the pulse width is controlled so that the output voltage matches the set value while limiting the output current. Further, since each DC power supply circuit receives the same signal from the transmission circuit 20 and forms a pulse signal for performing the switching operation, the switching operations of all the DC power supply circuits are necessarily synchronized. . From this, it can be seen that even if the voltage control circuit and the synchronizing circuit, which are conventionally provided in each DC power supply circuit, are deleted, the same function as the conventional one is provided.

Example 2. FIG. 2 is a circuit configuration diagram showing a second embodiment of the present invention, in which 1 to 22 in the figure are the same as or equivalent to the above-mentioned conventional circuit and the circuit described in the first embodiment, and 23 is a pulse width setting circuit. A PNM modulation circuit for converting the pulse width signal sent from 19 into a PNM signal and producing a clock signal from the pulse width signal, and 24 is a demodulation circuit for demodulating the PNM signal received by the receiving circuit 22 into a pulse width signal. Is.

FIG. 3 is a signal waveform diagram for explaining the operation of the embodiment shown in FIG. 2. The symbol A used in FIG. 2 is in the pulse width setting circuit 19 and determines the switching frequency. Oscillator output waveform and voltage control circuit 1
The figure which shows the output signal from 1, A is the pulse width setting circuit 1
9 is an output waveform diagram of C, C is a PNM signal waveform diagram modulated by the PNM modulation circuit 23, D is a clock signal waveform diagram generated from the pulse width signal of the pulse width setting circuit 19 by the PNM modulation circuit 23, and E is a demodulation circuit. FIG. 7 is a signal waveform diagram after demodulating a PNM signal into a pulse width signal by H.24.

The operation will be described in detail below with reference to the drawings. In the configuration of FIG. 2, the pulse width setting circuit 19 outputs the pulse width signal shown in B of FIG. The PNM modulation circuit 23 oscillates at a frequency higher than the frequency of the pulse width signal by 1 to 2 digits only while the pulse width signal shown in FIG. Send to circuit 20. At the same time, the PNM modulation circuit 23 changes the pulse width signal of the pulse width setting circuit 19 from High to Lo.
When it changes to w, it sends the clock signal of a constant width shown in FIG. The transmission circuit 20 is a high frequency PN
The M signal and the clock signal are transmitted to each DC power supply circuit, and the receiving circuit 22 in each DC power supply circuit receives the signal with a bandpass filter that passes only the frequency bands of the PNM signal and the clock signal that are sent, and the demodulation circuit 24. Demodulation circuit 24
Rotates the counter with the PNM signal sent from the time the clock signal rises until the next clock signal rises, and outputs a pulse width signal equivalent to the counted value at the same time as the clock signal rises. It is transmitted to the width control circuit 12. As a result, the output of the pulse width setting circuit 19 is accurately transmitted to the pulse width control circuit 12 without being affected by the distortion of the signal waveform due to noise or circuit impedance.

Example 3. FIG. 4 is a circuit configuration diagram showing a third embodiment of the present invention. Reference numerals 1 to 24 in the figure are the same as or equivalent to the conventional circuit and the circuits described in the first and second embodiments, and 25 is the same. This is a data correction circuit for correcting the difference between the output voltage value detected by the voltage control circuit 11 and the voltage value actually output by the DC power supply circuit 15.

FIG. 5 is a signal waveform diagram for explaining the operation of the embodiment in FIG. 4, and the symbols A to O used in FIG. 5 are the same as those in FIG. 3 used in the description of the second embodiment. Symbols which are the same as or correspond to the symbols shown are the PNM signal waveform diagrams after correction by the data correction circuit 25.

The operation will be described in detail below with reference to the drawings. From the voltage control circuit 11 to the pulse width setting circuit 19, P
The signal flow to the NM modulation circuit 23, the transmission circuit 20, and the reception circuit 22, and the function and operation of each circuit are as described in the second embodiment. The voltage value Vo output by the DC power supply circuit 15 is the input voltage Vin, the transformer 4
The number of turns of the primary winding is N1, the number of turns of the secondary winding is N2,
When the period during which the transistor 5 is on is Ton and the period during which it is off is Toff, it can be expressed by "Equation 1".

[0021]

[Equation 1]

In each DC power supply circuit connected in parallel, it is difficult to completely match the impedances existing between the primary power supply 1 and each DC power supply circuit, and the transformers in each DC power supply circuit. However, since there is an error in the coupling coefficient between the primary winding and the secondary winding, the voltage actually output is a value slightly different from the value shown in "Equation 1". Now, suppose that the temporary winding-to-secondary winding ratio of the transformer 4 of the DC power supply circuit 15 is larger than the average value N1 / N2 of the winding ratios of the respective direct current power supply circuits by ΔN and the input voltage Vin is also higher by ΔVin. Then, the output voltage of the DC power supply circuit 15 becomes larger than Vo, as can be seen from "Equation 1". Therefore, if the ON width of switching is corrected by α times and the output voltage is set to Vo, the correction value α becomes the value shown in “Equation 2”.

[0023]

[Equation 2]

Here, the data correction circuit 25 receives the PNM signal shown in FIG. 5C from the receiving circuit 22, and multiplies the number of pulses counted in the period in which the clock signal shown in FIG. 5D is Low by α times. At the same time when the next clock signal becomes High, the data signal corresponding to the PNM signal shown in FIG. The demodulation circuit 24 demodulates the data signal from the data correction circuit 25 into a pulse width signal, and transmits the pulse width signal shown in FIG. With this corrected pulse width signal,
Even if there is a slight difference in the winding ratio of the transformer 4 or the value of the input voltage, it is possible to realize the switching operation in which the output voltage value that is exactly the same as that of the other DC power supply circuits can be obtained.

Although the forward type switching regulator is used in the DC power supply circuit in the present embodiment, even if a half bridge type or full bridge type switching regulator is used, it is easy to obtain the same effect. Can be imagined.

[0026]

As described above, according to the first embodiment of the present invention, a plurality of DC power supply circuits connected in parallel form a voltage control circuit and a synchronizing circuit, and a DC power supply unit generates a synchronizing signal. The circuit can be eliminated, and a more simplified low-cost DC power supply device can be realized.

According to the second embodiment of the present invention, the voltage control circuit and the synchronizing circuit are removed from each of the DC power supply circuits connected in parallel, and the synchronizing signal generating circuit is removed from the DC power supply device. In addition, the PNM modulation of the voltage control signal that has already been converted into a pulse width signal allows stable switching and voltage control with a very simple circuit, without being affected by external noise. A DC power supply device with high performance can be realized.

According to the third embodiment of the present invention, the voltage control circuit and the synchronizing circuit are removed from each of the DC power supply circuits connected in parallel, and the synchronizing signal generating circuit is removed from the DC power supply device. In addition, the synchronous switching and voltage control can be performed without being affected by external noise, and the output voltage is always the same as that of other DC power supply circuits without being affected by the transformer performance of each DC power supply circuit and the variation of the input voltage. It is possible to realize a high-reliability DC power supply device that can supply the power and can make the stress of each DC power supply circuit uniform.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of a DC power supply device according to the present invention.

FIG. 2 is a diagram showing a second embodiment of the DC power supply device according to the present invention.

FIG. 3 is a diagram for explaining the operation of the second embodiment of the DC power supply device according to the present invention.

FIG. 4 is a diagram showing Embodiment 3 of the DC power supply device according to the present invention.

FIG. 5 is a diagram for explaining the operation of the third embodiment of the DC power supply device according to the present invention.

FIG. 6 is a diagram showing a conventional DC power supply device.

[Explanation of symbols]

1 primary power supply, 2 relay circuit, 3 input capacitors,
4 transformers, 5 transistors, 6 drive circuits, 7
Rectifier diode, 8 smoothing choke coil, 9 output capacitor, 10 current control circuit, 11 voltage control circuit, 12 pulse width control circuit, 13 relay drive circuit,
14 synchronization circuit, 15 1st current control type DC power supply device, 16 2nd current control type DC power supply device, 17 synchronization signal generation circuit, 18 load device, 19 pulse width setting circuit, 20 transmission circuit, 21 voltage control signal Generator circuit, 2
2 reception circuit, 23 PNM modulation circuit, 24 demodulation circuit, 25 data correction circuit.

Claims (3)

[Claims] 1. A relay circuit for shutting off an input current from a primary power supply, a capacitor for smoothing the input current, a transistor for switching a current from the DC power supply and the capacitor through a transformer, and for driving the transistor. Drive circuit, a rectifier diode connected to the secondary side of the transformer to rectify the current, a choke coil and a capacitor for smoothing the current from the rectifier diode, and an output current of the choke coil to detect a predetermined current. A current control circuit that controls the switching-on width of the transistor so that a current does not flow more than a value, a pulse-width control circuit that determines the switching-on width of the transistor from the current control circuit and a voltage control signal from the outside, and A relay drive circuit for turning off the relay circuit when an abnormality occurs, A synchronization that synchronizes the switching operation of all DC power supply circuits by connecting multiple current control type DC power supply circuits consisting of a synchronization circuit for synchronizing the switching operation of the transistors in parallel to supply power to the load device. In a DC power supply device equipped with a signal generation circuit,
A voltage control circuit that detects a voltage at the input stage of the load device and controls the switching-on width of the transistors of each DC power supply circuit, and a pulse width that determines the on-width of the transistor by a signal from the voltage control circuit. A voltage control signal generation circuit including a setting circuit and a transmission circuit that transmits the output signal of the pulse width setting circuit to each DC power supply circuit, and the pulse width when receiving a signal from the transmission circuit in each DC power supply circuit A DC power supply device comprising a receiving circuit for sending a voltage control signal to a control circuit in each DC power supply circuit. 2. A voltage control signal generating circuit is provided with a pulse number modulating circuit for converting the pulse width signal from the pulse width setting circuit into a pulse number signal and sending it to a transmitting circuit, and a receiving circuit in each DC power supply circuit. 2. The DC power supply device according to claim 1, further comprising a demodulation circuit for demodulating the pulse number signal into a pulse width signal between the pulse width control circuits. 3. A pulse number signal from the receiving circuit is adjusted between the receiving circuit and the demodulating circuit in accordance with a winding error of a transformer of each DC power supply circuit or a subtle variation in input voltage value. The data correction circuit for correcting and matching the voltage value detected by the voltage control circuit with the voltage value output by each DC power supply circuit is provided in the DC power supply circuit. DC power supply.