RU2832859C1 - Variable voltage stabilizer - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, namely to AC voltage stabilizers, and is intended for use in power supply systems. AC voltage stabilizer comprises a phase detector, an integrator, a sinusoidal generator, a balancing device, an amplitude stabilizer, a comparator, an output amplifier, a threshold device, a transformer and a protection unit. Protection unit has a constant voltage source, a pulse former, an optotriac, an L-circuit, a magnetic conductor with an air gap, a magnetic diode, a voltage divider, a variable resistor, a comparator, a JK trigger and a differentiating circuit.

EFFECT: expansion of functional capabilities with simultaneous increase of reliability.

1 cl, 1 dwg

Description

Field of technology to which the invention relates

The invention relates to electrical engineering, namely to AC voltage stabilizers, and is intended for use in power supply systems.

State of the art

A multi-stage AC voltage stabilizer is known (patent RU No. 2237270, IPC G05F 1/30, H02M 5/12), containing a booster transformer source, a key regulating element, a smoothing filter, a control element, and a reference sinusoidal voltage source synchronized with the mains voltage.

The disadvantage of this device is that the output voltage is stabilized using step adjustment and that if the input voltage has a distorted sine wave shape, then the output voltage will have the same shape.

The closest analogue-prototype to the claimed technical solution is an alternating voltage stabilizer (patent RU No. 2344463, IPC G05F 1/30).

An alternating voltage stabilizer comprises a phase detector, an integrator, a sinusoidal generator, a symmetrizer, an amplitude stabilizer, a comparison device, an output amplifier, a threshold device, a transformer, wherein the input voltage is fed to the first terminal of the secondary winding of the transformer and the first input of the phase detector, the output of which is connected to the input of the integrator, the output of which is connected to the input of the sinusoidal generator, the output of which is connected to the input of the symmetrizer, the output of which is connected to the input of the amplitude stabilizer, the output of which is connected to the first input of the comparison device and the second input of the phase detector, from the second terminal of the secondary winding of the transformer the output voltage is fed to the second input of the comparison device, the output of which is connected to the first input of the output amplifier and the input of the threshold device, the output of which is connected to the second input of the output amplifier, the first output of which is connected to the first terminal of the primary winding of the transformer, the second output to the second terminal of the primary winding of the transformer, the third output to the third terminal of the primary winding of the transformer.

The disadvantages of this device are limited functionality and low reliability.

Limited functionality is due to the lack of ability to control the amount of permissible current.

Low reliability is due to the lack of protection against possible current overload.

Disclosure of invention

The technical result that can be achieved with the help of the proposed invention is reduced to the expansion of functional capabilities while simultaneously increasing reliability.

The technical result is achieved in that the AC voltage stabilizer contains a phase detector, an integrator, a sinusoidal generator, a symmetrizer, an amplitude stabilizer, a comparison device, an output amplifier, a threshold device, a transformer, wherein: the first terminal of the secondary winding of the transformer is connected to the first input of the phase detector, the output of which is connected to the input of the integrator, the output of which is connected to the input of the sinusoidal generator, the output of which is connected to the input of the symmetrizer, the output of which is connected to the input of the amplitude stabilizer, the output of which is connected to the first input of the comparison device and the second input of the phase detector; the second terminal of the secondary winding of the transformer is connected to the second input of the comparison device, the output of which is connected to the first input of the output amplifier and the input of the threshold device, the output of which is connected to the second input of the output amplifier, the first output of which is connected to the first terminal of the primary winding of the transformer, the second output to the second terminal of the primary winding of the transformer, the third output to the third terminal of the primary winding of the transformer, a protection unit is introduced, wherein: the first and second inputs of the protection unit are connected to the network (the first input to the phase, the second to zero); the third input is connected to the second terminal of the secondary winding of the transformer and the second input of the comparison device; the first output is connected to the first terminal of the secondary winding of the transformer and the first input of the phase detector; the second output serves as the phase output of the device.

The protection unit comprises a constant voltage source, a pulse former, an opto-simistor, an L-circuit serving as a single-turn winding of a magnetic circuit with an air gap, a magnetodiode, a voltage divider, a variable resistor, a comparator, a JK trigger, a differentiating circuit, wherein: the first and second inputs of the constant voltage source are connected to the first and second inputs of the protection unit; the first and second outputs of the constant voltage source serve to provide power supply to the elements of the device; the third output of the constant voltage source, with a logical one level, is connected to the first terminal of the variable resistor, the C-input of the JK trigger and the first inputs of the voltage divider and the differentiating circuit, the second inputs of which are grounded, and the outputs are connected, respectively, to the first input of the comparator and the J-input of the JK trigger; the second and third terminals of the variable resistor are connected to the second input of the comparator and the anode of the magnetodiode, the cathode of which is grounded; the output of the comparator is connected to the K input of the JK trigger, the Q output of which is connected to the input of the pulse generator, the outputs of which serve as control inputs of the opto-simistor, the input of which is connected to the first input of the protection unit, and the output serves as the first output of the protection unit; the first output of the L-circuit serves as the third input of the protection unit; the second output of the L-circuit serves as the second output of the protection unit.

Brief description of the drawings

Fig. 1 shows the functional diagram of the AC voltage stabilizer.

Implementation of the invention

The AC voltage stabilizer (Fig. 1) comprises a phase detector 1, an integrator 2, a sinusoidal generator 3, a balun 4, an amplitude stabilizer 5, a comparison device 6, an output amplifier 7, a threshold device 8, a transformer 9, a protection unit 10, wherein: the first and second inputs of the protection unit 10 are connected to the network (the first input to the phase, the second to zero); the third input of the protection unit 10 is connected to the second terminal of the secondary winding of the transformer 9 and the second input of the comparison device 6; the first output of the protection unit 10 is connected to the first terminal of the secondary winding of the transformer 9 and the first input of the phase detector 1; the second output of the protection unit 10 serves as the phase output of the device; the output of the phase detector 1 is connected to the input of the integrator 2, the output of which is connected to the input of the sinusoidal generator 3; the output of the sinusoidal generator 3 is connected to the input of the balun 4, the output of which is connected to the input of the amplitude stabilizer 5; the output of the amplitude stabilizer 5 is connected to the first input of the comparison device 6 and the second input of the phase detector 1; the output of the comparison device 6 is connected to the first input of the output amplifier 7 and the input of the threshold device 8, the output of which is connected to the second input of the output amplifier 7, the first output of which is connected to the first terminal of the primary winding of the transformer 9, the second output to the second terminal of the primary winding of the transformer 9, the third output to the third terminal of the primary winding of the transformer 9.

The protection unit 10 comprises a constant voltage source 11, a pulse generator 12, an opto-simistor 13, an L-circuit 14 serving as a single-turn winding of a magnetic circuit 15 with an air gap, a magnetodiode 16, a variable resistor 17, a comparator 18, a voltage divider 19, a JK trigger 20, a differentiating circuit 21, wherein: the first and second inputs of the constant voltage source 11 are connected to the first and second inputs of the protection unit 10; the first and second outputs of the constant voltage source 11 serve to provide power supply to the elements of the device; the third output of the constant voltage source 11, with the logical one level, is connected to the first output of the variable resistor 17, the C-input of the JK trigger 20 and the first inputs of the voltage divider 19 and the differentiating circuit 21, the second inputs of which are grounded, and the outputs are connected, respectively, to the first input of the comparator 18 and the J-input of the JK trigger 20; the second and third outputs of the variable resistor 17 are connected to the second input of the comparator 18 and the anode of the magnetodiode 16, the cathode of which is grounded; the output of the comparator 18 is connected to the K-input of the JK trigger 20, the Q-output of which is connected to the input of the pulse generator 12, the outputs of which serve as control inputs of the opto-simistor 13, the input of which is connected to the first input of the protection unit 10, and the output serves as the first output of the protection unit 10; the first terminal of the L-circuit 14 serves as the third input of the protection unit 10; the second terminal of the L-circuit 14 serves as the second output of the protection unit 10.

The proposed AC voltage stabilizer operates as follows.

When power is supplied to inputs A, N of the stabilizer, voltage U _in is supplied to the first and second inputs of the constant voltage source 11, which supplies power to the elements of the device.

Since there is no current overload, protection unit 10 ensures the switching connection of the phase wire of the network with the first terminal of the secondary winding of transformer 9 and the first input of phase detector 1.

The sinusoidal generator 3 produces a sinusoidal voltage with a frequency of 50 Hz, the generator frequency can vary within small limits, the balun 4 ensures equality of the positive and negative half-waves at the output, the amplitude stabilizer 5 allows maintaining the sinusoid amplitude at its output with high accuracy, the comparison device 6 compares the output voltage of 209 V/50 Hz with the reference, and a difference signal is formed at its output. The output amplifier 7 amplifies the signal of the comparison device and feeds it to the transformer 9, which increases or decreases the voltage supplied to the input (depending on the phase of the difference signal). The threshold device 8 produces a signal for short-circuiting the transformer 9 if the compensation voltage is less than a specified threshold (for example, 1 V). Phase detector 1 compares the phase of the input voltage with the phase of the obtained reference sinusoidal signal, the signal proportional to the phase difference is fed to integrator 2. The signal from integrator 2 is fed to sinusoidal generator 3 to adjust its frequency and phase.

As shown above, at the moment of supplying power to the stabilizer, protection unit 10 provides a switching connection that transfers the stabilizer to the working state.

The switching itself is caused by the operation of the opto-simistor 13 on command from the pulse generator 12. Due to the establishment of a logical zero level at the K input, and a logical one level at the C input, J input, and therefore at the Q output of the JK trigger 20.

The logical one level at the C-input of the JK trigger 20 is determined by the potential from the third output of the constant voltage source 12.

The logical one level at the J-input of the JK trigger 20 is caused by a voltage surge at the output of the differentiating circuit 21 at the moment the potential is supplied from the third output of the constant voltage source 12.

The logical zero level at the K-input of the JK trigger 20 is caused by the non-operation of the comparator 18 (due to the absence of a current overload).

The comparator 18 is triggered under the condition

U _MD >U _DN (1)

where U _MD is the voltage drop at the base of magnetodiode 16, supplied to the second input (U _in+ ) of comparator 18;

U _DN is the voltage from the output of voltage divider 19, supplied to the first input (U _in- ) of comparator 18.

The output voltage of voltage divider 19, U _DN , is proportional to the voltage from the third output of DC voltage source 12.

The voltage drop across the base of magnetodiode 16, U _MD , is determined by:

- the voltage value from the third output of the DC voltage source 12;

- resistance of variable resistor 17;

- the resistance of the base of the magnetodiode 16, depending on the magnitude of the transverse magnetic field.

And since the resistance of the base of the magnetodiode 16 increases with the increase of the transverse magnetic field, the value of which is determined by the value of the load current of the stabilizer flowing in the L-circuit 14, which serves as a single-turn winding of the magnetic circuit 15 with an air gap, the moment of operation of the comparator 18 will be determined by the value of the load current and the pre-set value of the resistance of the variable resistor 17.

Which, in turn, ensures:

- control of the value of the permissible load current;

- protection against possible current overload,

and therefore expansion of the stabilizer’s functional capabilities while simultaneously increasing reliability.

Claims (1)

An alternating voltage stabilizer comprising a phase detector, an integrator, a sinusoidal generator, a symmetrizer, an amplitude stabilizer, a comparison device, an output amplifier, a threshold device, a transformer, wherein: the first terminal of the secondary winding of the transformer is connected to the first input of the phase detector, the output of which is connected to the input of the integrator, the output of which is connected to the input of the sinusoidal generator, the output of which is connected to the input of the symmetrizer, the output of which is connected to the input of the amplitude stabilizer, the output of which is connected to the first input of the comparison device and the second input of the phase detector; the second terminal of the secondary winding of the transformer is connected to the second input of the comparison device, the output of which is connected to the first input of the output amplifier and the input of the threshold device, the output of which is connected to the second input of the output amplifier, the first output of which is connected to the first terminal of the primary winding of the transformer, the second output to the second terminal of the primary winding of the transformer, the third output to the third terminal of the primary winding of the transformer, characterized in that a protection unit is introduced into the device, wherein: the first and second inputs of the protection unit are connected to the phase and zero of the network, respectively, the third input of the protection unit is connected to the second terminal of the secondary winding of the transformer and the second input of the comparison device, the first output of the protection unit is connected to the first terminal of the secondary winding of the transformer and the first input of the phase detector, the second output serves as the phase output of the device, the protection unit comprises a DC voltage source, a pulse shaper, an opto-simistor, an L-circuit serving as a single-turn winding of a magnetic circuit with an air gap, a magnetodiode, a voltage divider, a variable resistor, a comparator, a JK trigger, a differentiating circuit, wherein the first and second inputs of the constant voltage source are connected to the first and second inputs of the protection unit, the first and second outputs of the constant voltage source serve to provide power supply to the elements of the device, the third output of the constant voltage source with a logical one level is connected to the first terminal of the variable resistor, the C-input of the JK trigger and the first inputs of the voltage divider and the differentiating circuit, the second inputs of which are grounded, and the outputs are connected respectively to the first input of the comparator and the J-input of the JK trigger, the second and third terminals of the variable resistor are connected to the second input of the comparator and the anode of the magnetodiode, the cathode of which is grounded, the output of the comparator is connected to the K-input of the JK trigger, the Q-output of which is connected to the input of the pulse generator, the outputs of which serve as control inputs of the opto-simistor, the input of which is connected to the first input of the protection unit, and the output serves as the first output of the protection unit, the first terminal of the L-circuit serves as the third input of the protection unit, the second terminal of the L-circuit serves as the second output of the protection unit.

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