JPS58136235A - Parallel operation system for dc constant- voltage device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 葎）Technical field of invention The present invention relates to a parallel operation system for DC voltage regulators.

Background of the Technology DC voltage regulators are often used as power supply circuits in electrical equipment to supply DC voltage with little voltage fluctuation to electrical circuits to ensure stable operation.

DC power supplies have a variety of voltage and current combinations, so in order to accommodate this, DC voltage regulators are made into series based on their current capacity, for example, in order to improve the performance-price ratio, including maintenance. While they are provided as units corresponding to current values, in order to improve the reliability of the power supply, a method is used in which a plurality of units of the same capacity are connected in parallel on a DC voltage regulator and operated.

(c) Prior Art and Problems FIG. 1 shows a block diagram of a conventional parallel operation system for a DC voltage regulator 1.1a.

When performing parallel operation by connecting input and output terminals of common polarity in parallel, it is desirable that each device 1.1m has an equal load. Operation with a balanced load is not necessarily carried out due to changes or setting errors in the error amplifiers 2 and 2a.For example, errors in the output voltage settings of the device L and 1m, or errors in temperature Iff during operation. If the setting value is slightly higher than that of the device L, that is, the incorrect amplifier 2, then a higher voltage is applied to the control terminal of the control circuit 3, and the device L first applies the current to the load 4. There is a case where the load current of the device 1a is e. When the output current of the device 1 exceeds the rated value and enters the drooping characteristic region, or drops below the voltage drop of the control element 3 - the output voltage of the control device 1a, current is supplied from the device 1a. In parallel operation of this type of DC voltage regulator, one side has a heavy load;
On the other hand, since it is light, reliability problems occur. In addition, in the case of parallel redundant operation, if a failure occurs on the full load side when one side is full load and the other is no load, and the no load device is replaced with full load, the output voltage may fluctuate, etc. The disadvantage is that the negative impact on the load is greater than that of a uniform load.

(d) Object of the Invention In order to eliminate this drawback, it is an object of the present invention to provide a means for equalizing the loads of a plurality of control elements in a DC constant voltage device operated in parallel.

(・) The structure and purpose of the invention is to detect a signal obtained by comparing the output voltage with a reference voltage using the error amplifier according to the present invention, and to convert the DC input voltage into the step-down side at or the conduction angle t-fil of the repetitive driving pulse.
In an operation method in which multiple DC voltage regulators are connected in parallel to obtain a constant DC voltage by inputting it to the control circuit to be controlled, the output signal of the error amplifier is connected in parallel via a diode or buffer amplifier's check function. To provide a parallel operation system for DC voltage regulators, characterized in that each control circuit in a plurality of DC voltage regulators is controlled by a parallel parallel output signal of a common error amplifier. This can be achieved by

(f) Embodiment of the Invention An embodiment of the invention will be described below with reference to the drawings.

In Fig. 2, 1.1a is a DC voltage regulator, 2゜2a is an error amplifier, 3.3& is a control circuit, 4 is a load, and RItl.
+m is a resistor and D is a diode.

In FIG. 2, except for the resistor Rs and the diode Dt-, the structure and function are common to the parallel operation system in the conventional DC voltage regulator using the first WJ#c.

2nd wJO In this example, after a diode is connected to the output of the error amplifier 2.21, it is input to the control circuit 3.3a and is also drawn out to the outside to be connected to another DC voltage regulator 1.14.
and the control circuit 3.31 are mutually connected in the pot, and the input of the control circuit 3,310 is driven by the high output voltage signal of the error amplifier 2.21, and the lower voltage is cut off by a diode. Therefore, the voltage step-down control operation of the control circuit 3.31 follows only the signal output of one of the error amplifiers 2, for example.If the functions of the control circuits 3.31 are equal, the loads will be equalized. If there is an error in the characteristics between the control circuits 3 and 3a, there will be an unbalance to that extent, but the load distribution in the simple mode will no longer be full load versus no load, and will be improved. Note that the resistance R+R* is a voltage division resistance, and Rs is a leakage resistance.

5Ill*x and FIG. 4 show other embodiments.

3rd Ill is an example in which it is applied to a DC-DC converter type L DC voltage regulator 1b, lc, and the control circuit 3b
The function in s3* is to select the slice level of the sawtooth pulse using a comparator, convert the detected output signal to the error amplifier 2゜2a into a pulse width, control the pace conduction angle of the drive transistor, and thereafter pass it through a transformer. Although rectifying and smoothing the DC output is different, error amplifiers 2a and 2b are connected in parallel with their output signals through diodes, and the L control circuit 3esd [common control This is the same as the embodiment shown in FIG. 2 above.

Moreover, in FIG. 4, parallel I1M is applied on the output side of the buffer amplification transistor Q in place of the diode D in FIG. 2, and in this case as well, priority is given to the output side of Q. One control circuit 3, 3a is commonly controlled by the output signal of any one of the error amplifiers. The output signals of other error amplifiers that are not given priority are blocked by the buffer amplification transistor Q. tThR4 is for collector voltage drop.

-) Detailed explanation of the invention 1. The present invention relates to fluctuations in components and characteristics, set value errors, etc. that occur in the error amplifier 2.21 compared to parallel operation using a conventional DC voltage regulator. As a result, the unbalance of the load current is removed, and a parallel operation method of conventional DC voltage regulators with high reliability can be obtained.

[Brief explanation of drawings]

'M1 is a block diagram showing parallel operation system tubes of a conventional DC constant voltage device, and FIG. 2 is a block diagram showing parallel operation system tubes of a flow chamber voltage device in an embodiment of the present invention. FIG. 4 is a schematic diagram of other embodiments of the present invention. In WJ, 1.1 &e be e* do @ is a DC voltage regulator, 2.21 is an error amplifier, and 3.3a. bee is a control circuit, 4 is a load, Q is a transistor, and D is a diode. Rod 1 (2) 2 flutes

Claims (1)

[Claims] A signal obtained by comparing the output voltage with the total reference voltage using an error amplifier is input to a control circuit that controls the step-down side of the DC input voltage or the conduction angle of the repetitive drive pulse to obtain a constant DC output voltage. In an operating system in which several voltage regulators are connected in parallel, the error amplifier output signal t diode or the buffer amplifier checker 1i! A patented parallel operation system for DC voltage regulators in which each control circuit in a plurality of DC voltage regulators is controlled by a common parallel-connected output signal of the differential amplifier.