SU769678A1 - Device for automatic switching-on of standby power supply - Google Patents

Description

one

The device relates to electrical engineering and is intended to power the responsible electrical receivers, which do not allow interruptions in the power supply.

A device is known, where an EC-1 shorting connector with a proper response time of 0.01-0.03 s 1 can be used as a shunt switching apparatus.

However, this device does not provide the minimum time to connect the reserve in the absence of phase voltage or short circuit in the load.

The closest technical solution to the invention is a device for automatically turning on a backup power supply of a power system with input switches and a switch-split system of ladders containing load current sensors connected to a short-circuit block in each section (c. C)

The purpose of the invention is to increase the speed of the device.

The goal is achieved by the fact that the device for automatic switching on the backup power supply with the input switches and the switch-sectioned system of trains, containing load current sensors connected to the block k. 3 in each section, are inserted into each input of the front-edge pulse shaping unit phase voltage monitoring, coincidence circuit, five circuits

5 OR, two triggers, as well as two schemes of coincidence of the sectional switch, the scheme OR of the sectional switch and the pulse generator, with the outputs of the leading-edge pulse shaping units

10 of each input is connected to the first inputs of the input switch coincidence circuit and the first inputs of the first sectional switch matrices, to the block inputs. The second outputs of the shaping blocks are connected to the inputs of the single-phase voltage control blocks, the first outputs of which are connected to the inputs of the first OR circuit and the second with the inputs of the second OR circuit, the output of the first OR circuit is connected to the first input of the first trigger and to the first input of the third OR circuit, the output of which is connected to the first input of the second trigger, the output of the second OR circuit One with the second input of the second trigger and the first input of the fourth OR circuit, the output of which is connected to the second input of the first trigger, and the second input to the second input of the third OR circuit, to the third input

30 third circuit OR other switch

the input and output of the fifth OR circuit, whose inputs are connected to the cc block. The third input of the third circuit OR is connected to the second input of the third circuit OR switch of another input, the output of the first trigger is connected to the inputs of the coincidence circuit of the switch, the output of the second trigger is connected to the inputs of the second coincidence circuits of the section switch, the outputs of which are connected via an OR circuit to the section switch, the output of the pulse generator is connected to the voltage phase control units and the blocks to. 3., the outputs of the coincidence circuits are connected to you key input.

On fng. 1 shows the general scheme of the device; in fig. 2 - time diagram.

The device includes section 1, input switch 2, load 3, section 4, input switch 5, load 6, sectioning switch 7, blocks 8-10 of the leading edge pulses of both IPF4 and IPF voltage conditions, each phase A, B, C of the first section, their outputs are connected to the inputs of the coincidence circuits 11 input switches of the first coincidence circuits 12 of the sectioning switch, short circuit blocks 13, blocks 14-16 of forming the leading edge of both voltage voltages for each voltage of the second input, outs inen with inputs of the circuit of the switch 17, the second input of the second circuit 18 of the sectioning switch, the short circuit blocks 19 of the second section, the blocks 20-25 of the phase voltage control of the second section, the pulse generator 26, the first circuits OR 27 and 28, the first triggers 29 and 30, the second circuit OR 31 and 32, the second trigger 33 and 34, the circuit OR 35 of the partition switch, the third circuit OR 36 and 37, the fourth circuit OR 38 and 39, the current sensors 40 and 41, the circuit OR 42 and 43.

The device works as follows.

Section 1 through the input switch 2 energizes the load 3. Section 4 feeds the load 6 through the input switch 5. When one of the phases in the section 1 is disconnected, the switch 2 is turned off and the sectional switch 7 connects to the load 3 the section 4 voltage. section 4, the switch 5 is turned off and the switch 7 connects to the load 6 the voltage of section 1.

The formation blocks 8-10 for each phase of the first section generate the leading edge pulses of positive ITP + and negative IAP-half-phases of phase voltage, which are fed to the corresponding coincidence circuits 11 of the input switch, coincidence circuits 12

sectioning switch and blocks 13 short circuit.

The formation blocks 14-16 for each phase of the second section form IF4-, IAP-- pulses, which are fed to the corresponding coincidence circuits 17 of the input switch and sectioning switch 18 and the short-circuit blocks 19.

For example, the Schmitt triggers of blocks are transferred for a period of positive and negative half-periods from the reference voltage EO, as shown in FIG. 2, say, for phase A. On collectors of transistors, respectively, opposite-polarized rectangular pulses Tk1, Tk2 Schmitt triggers of positive and TcZ, Tk4 Schmitt triggers of negative half-cycles are formed. From the front

pulse fronts Tk1, TkZ are formed, respectively, the pulses of the leading edge of the IAP + positive and IAP-negative half-periods, which arrive at the inputs of these circuits. Besides,

Voltages Tk1, Tk2, TkZ, Tk4 of the corresponding phase enter into blocks 20-25, consisting of AND, OR, BANNER schemes, which by voltage Tk1, Tk4 and Tk2, TkZ to points K, E form the signal

a series of impulses of the generator 26 in the presence of phase voltage, and after points K, E - a signal of the absence of phase voltage. Hence, the signals for switching of the corresponding section are formed from the moment

Schrettr triggers at points K, E, which is fractions of microseconds.

The signals of the presence of phase voltage from the outputs 20-25 are received, respectively, at the inputs of the circuits OR 27 and 28 of this

the sections that by the output signal in the form of a series of pulses hold the triggers 29 and 30 in a stable position, in which their output voltages are allowed, respectively, to the circuits And and 17 to skip

IAP, IAP pulses to input switches 2 and 5, through which voltages are applied to loads 3 and 6. Signals of the absence of phase voltage from the block outputs are received, respectively, to the inputs of the OR circuit 31 and 32 of this section, which are held by the output signal 33 and 34 in a stable position in which their output signals allow, respectively, circuits 12 and 18 to pass

pulses of an IAP-4, IAP-operable section on the OR circuit 35 of the partitioning switch 7 for switching on.

The triggers 29, 30, 33, and 34 are reset by the B stable states by the signals of the corresponding OR circuit 36, 37, 38, 39.

Current sensors 40 and 41 of loads 3 and 6 with permissible currents for each phase produce harmonic voltages with a frequency less than, for example, generator 26.

With a short circuit in the load in phase (A, B, C), the frequency of the current sensor of this phase becomes greater than the frequency of the generator 26, say, during the time interval of the pulses of the IAP +, IAP- and short circuit block but this phase of this section through the OR circuit 42, 43 and, respectively, through circuits 36, 37, 39 or 37, 38, 39, flip-flop triggers 29, 33 or 30, 34, thereby disconnecting the load from the supply section.

Blocks 8, 9, 10, 14, 15 and 16 form pulses of IAP -) -, IAP - with a delay of 3-5 MKS from the beginning of half periods in order to eliminate cutoffs on the thyristors of the switches 2, 5, 7 at significant power loads 3 , 6 and nodayutsya on the circuit And, 12, 17, 28, the output impulses which do not go to the control electrodes of the thyristors.

With low power loads, when voltage cutoffs can be neglected, generator circuits 26 can be applied to circuits 11, 12, 17, and 18.

Claims (2)

1. USSR author's certificate number 256059, cl. H 02J 9/06, 1968. 2. Barzam A. System automation. M., “Energie, 1973, p. 324 (prototype).