SU1413691A1 - System of standby d.c. power supply for load - Google Patents

Abstract

The invention relates to backup power systems, to the means of switching batteries in automatic power plants with a booster converter. The purpose of the invention is to improve the stability of the voltage on the load during transients when the supply voltage disappears or the uncontrolled rectifier malfunctions. The load is powered from a series-connected uncontrolled meter collector (LV) and booster converter. By reducing the output voltage of the NUV to a predetermined value due to a decrease in the supply voltage or a malfunction of the NUV, a valid (thyristor) key is quickly opened, which connects an external battery (instead of the NUV). At the same time, a signal is given to turn on the contactor. When the contactor is turned on, one of its contacts shunts the thyristor switch, and the other opens the circuit of the contact switch. The thyristor key is controlled by a signal from the output of the logic circuit through a 3 dc current generator. The first input of the logic circuit is supplied with a signal from the output of the comparator comparing the output voltage of the LVU with the reference voltage, and between the second input of the circuit and its output a circuit is turned on; the circuit consisting of a single pin of the contactor and the contactor coil is connected in series. When the output voltage of the NU is restored, the icoHTaK control circuit disconnects the contactor, and the device returns to its initial state 1 sludge.

Description

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The image refers to backup power systems, to the means of switching batteries in automatic power supply installations with a voltage-to-batch converter.

The aim of the invention is to increase the voltage stability at the load during transients when the supply voltage disappears or the uncontrolled rectifier malfunctions.

The drawing shows (the operational diagram of the proposed system.

The system for back-up DC power supply contains a controlled rectifier 1 with terminals 2 for connection to the power supply network, a booster converter 3, connected in series with the rectifier Mitel, a load 4 connected to me, to the positive output of the rectifier and a negative terminal of the converter, a battery 5, the positive terminal of which is connected to the positive rectifier output, and a negative terminal to the cathode of the thyristor switch 6, the anode of which is connected to the common point of the rectifier and converter, - the Key 6 is shunted by the closing pin the act 7.1 of the contactor, which also contains the opening contact 7.2, inserted into the control circuit of the switch 6 in series with the coil 7.3 connected in series with the contactor control circuit 8. The common point of the rectifier 1 and converter p-3- 3 is connected to the input of voltage divider 9, the output of which is connected to the first input of comparator 10, the second input of comparator 10 is connected to source 11 of the reference voltage, and the output to the first input of logic circuit 12"

Logic 12 contains the first logical element AND-NOT 13, the inputs "from which are interconnected and are the first input of the logic circuit 12, and the output to the first input of the second logical element AND-NOT 14 and 8 input RS-flip-flop 15, R The input of which is connected to the output of the second NAND gate 14, the second of the last of the last one being the second input of the logic circuit 12, and the inertial output of the RS flip-flop 15 is its output. The second logic input of the logic circuit 12 is connected to the free viewport of the ontaror control circuit 8, and the output from freedoms:

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the coil 7.3 of the contactor and the input of the amplifier 16 DC., the output of which is connected via a break contact 7.2 to the control circuit of the switch 6i.

The system works as follows.

A comparator 10 times rotates the voltage at the output of the voltage of the Iel I with the specified reference voltage of the source 11. When the voltage decreases at the output of the rectifier 1 to the specified value at the output of the comparator 10, it appears as -. physical 1, at. this is at the output of the NAND 13 logic element, the logical input O appears at the first input of the NAND logic element 14 and at the S input of the trigger. 15 At the second input of the NAND gate .14 and at the R input of the trigger The 15 signal is equal to logical 1, and on the inverting output of the RS flip-flop 15 to logical O, which leads to the appearance of a signal at the output of the amplifier 16, the open key 6. In this case, in series with the converter 3, the battery 5 is turned on and voltage at load 4. Simultaneously, the circuit is turned on (with a delay due to the on time) and its contact 7.1 shunts key 6, and contact 7.2 opens the control circuit, key 6 closes. When battery 5 is connected to converter 3, logical O appears at the output of comparator 10, but RS-flip-flop 15 does not change state and keeps the contactor on.

When restoring the mains voltage or rectifying the malfunction of the rectifier 1, the contactor control circuit 8 disconnects the contactor, affecting the R input of the RS flip-flop 15 via the NAND gate 14, and the system returns to its original state.

Claims (1)

Invention Formula System for backup power on; DC loads, containing a load connected to an unmanaged rectifier connected in series with a direct current, the input terminals of which are intended for sub-. connection to the mains supply, and to the add-on converter, a battery, the plus terminal of which is connected to the positive terminal of the uncontrolled rectifier, and the negative terminal - to the thyristor cathode connected to the contactor with a common terminal of the contactor, a common connection with the common connection of the contactor, shunt by the closing contact of the contactor, is connected with a common connection with the common connection of the contactor, shunt by the closing contact of the contactor, the common electrode connected to the common connection with the common connection of the contactor with the common contactor of the contactor, shunted with the common contact of the contactor, the common electrode connected to the common connection rectifier and booster converter, connected in series with the contactor coil and contactor control circuit, a comparator, the first input of which is connected via a voltage divider with a negative terminal the uncontrolled rectifier, and the second input - with a source of reference, for example. wives that, in order to increase the voltage stability at the load during transients when the supply voltage disappears or the uncontrolled rectifier fails, the comparator output is connected to the first the input of the logic circuit containing the first NAND logic element, whose inputs are about 7, are united and form the first input of the logic circuit, and the output is connected to the first input of the second NAND logic element and the S input of the RS trigger, the R input of which is connected to the output of the second logic element, in the second input of which is the second input of the logic circuit and is connected to the free output of the contactor control circuit, and the free output of the contactor coil is connected to the inverse output of the RS flip-flop, which is the output of the logic circuit a dc current filler, the output of which is connected through the disconnecting contact of the contactor to the trigger control circuit of the thyristor key.