RU33676U1 - Surge Protector - Google Patents

Abstract

1. An AC voltage stabilizer with overvoltage protection, containing input terminals for connecting the stabilizer to an unstabilized voltage source, stabilized voltage output terminals for connecting a load, input voltage control means, an adjustment transformer having several windings with switched terminals for regulating the output voltage, electromagnetic output voltage control relays, to the contact systems of which are connected switched outputs odes of the windings of the control transformer, a microprocessor-based device for controlling the switching of the power circuits of the windings of the output voltage control relays, which contains input terminals connected to the input voltage control means and output terminals connected to the control circuits of the power supply of the electromagnetic windings of the output voltage regulation relay, characterized in that in addition two nodes of the stabilizer protection against increased voltages at its input have been introduced: the short-circuit protection unit pulse surge voltage, in which the duration of one pulse does not exceed the duration of the half-cycle of the mains supply voltage, a node for protection against prolonged high voltages, for which the effective value of the input voltage of the network exceeds the set maximum permissible value, while the node for protection against short-term surge voltage contains voltage limiting elements, made on varistors and arresters, and the protection unit against prolonged high voltages contains an electromagnetic protection relay

Description

Known devices for discrete control of alternating voltage by switching the terminals of the windings of the transformer 1 to 5. In particular, a variable voltage regulator of discrete action, which contains a transformer with a partitioned winding, sections of which are connected in series with each other and with the input terminals, and with a microprocessor control device.

The disadvantage of such a device is its low reliability under conditions of overvoltage in the network, the risk of failure of both the stabilizer itself and the load connected to its output. This is because they are made without the use of special circuitry

solutions for their protection at high values of the amplitude of the mains voltage.

The closest analogue is an AC voltage stabilizer 6.

In it, at the input of the stabilizer, there is a power circuit breaker for long} 1s increased voltages.

The disadvantage of such a device, which is closest to the proposed one, is the danger of the stabilizer failing during short-time overvoltages, during which the electronic circuits of both the stabilizer and the load can fail before the contacts of the electromechanical circuit breaker open.

The task to which this technical solution is aimed is to eliminate these drawbacks, to protect the stabilizer itself and the load connected to it from any overvoltage.

The technical result achieved in this case is to increase the reliability of the stabilizer and the equipment connected to it by preventing malfunctions and failure during operation.

To solve this problem, the stabilizer is made as follows.

The AC voltage stabilizer with overvoltage protection has the following well-known technical solutions.

Input pins for connecting the stabilizer to an unstabilized voltage source.

Outputs of stabilized voltage for load connection.

switched outputs for regulating the output voltage.

Contact voltage electromagnetic relay

whose systems are connected to the switched terminals of the windings

regulation transformer.

Microprocessor-based power switching device

windings of said output voltage regulation relay,

which contains input pins connected to a control means

input voltage

and output leads connected to switching control circuits

winding power electromagnetic output control relays

voltage.

The signs that distinguish this stabilizer from the closest known solution 6 (prototype) are as follows.

In addition, two nodes of the stabilizer protection against increased voltages at its input were introduced:

node protection against short-term surge surges, in which the duration of one pulse does not exceed the duration of the half-period of the supply voltage;

node protection against prolonged high voltages, in which the effective value of the input mains voltage exceeds the set maximum permissible value.

The node protection against short-term surge surges contains voltage limiting elements made on varistors and arresters.

And the node for protection against prolonged overvoltage contains: an electromagnetic relay for protection against prolonged overvoltage with normally open contacts to disconnect the input circuits of the regulating transformer from the network at unacceptable long overvoltages;

as well as a power source of said electromagnetic relay for protection against prolonged high voltages and a microprocessor device for controlling the switching of power circuits of the relay windings. This power supply contains: an additional step-down transformer, a rectifier and a stabilizer

voltage for powering the microprocessor and said electromagnetic

Relays for protection against continuous overvoltage.

Continuous Overvoltage Relay Winding Power Circuit

connected to the output of said microprocessor device, which

generates a signal to turn off this relay when exceeded by the current

the value of the input voltage of the network is an acceptable level.

The input terminals of the stabilizer are electrically connected to the input

stabilizer regulating transformer circuits through

serially connected surge protection unit

and contact system of an electromagnetic relay of protection against long-term

increased voltages exceeding the permissible current level

network voltage values.

And the input circuit of an additional step-down transformer node

the protection is electrically connected to the input terminals of the stabilizer

by connecting to electrical circuits between

stabilizer input terminals and contact system input

electromagnetic relay of protection against prolonged overvoltage.

At the same time, the microprocessor device, in addition to the control circuit

switching power supply of relay windings intended for regulation

output voltage, contains the following circuits:

a circuit for calculating the effective value of the input voltage;

maximum detection circuit for input voltage

permissible value of the effective voltage value;

and control circuit for turning off the power of the winding of the protection relay against

long-term increased voltages when detected by microprocessor

device exceeding the input voltage of the network maximum permissible

the magnitude of the effective voltage value.

This ensures an emergency shutdown of power circuits.

hazardous overvoltage transformer

network present on the input terminals of the stabilizer. Podso voltage electr. 1,2 - conclusions for connecting the input voltage of the network; 3 - output for grounding; 4, 5 - terminals of the output voltage of the stabilizer for load unification; 6- adjusting transformer; 7- winding of the output voltage of the stabilizer; 8-switched adjusting winding; 9, 10 - electromagnetic relays for regulating the output voltage with means for switching the power circuits of their windings; 11 - microprocessor control device for switching the power circuits of relay windings; 12- means for controlling the input voltage and generating a normalized signal; 13- node protection against prolonged high voltages; 14- electromagnetic relay of protection against long-term increased contacts with normally open contacts; 15- step-down transformer; 16- rectifier and stabilizer to power the microprocessor and the electromagnetic protection relay against prolonged high voltages; 17 - means of protection of the transformer 15 from overheating; 18-node protection against short-term surge surges;

electrical circuits. Conclusions 1,2-input, designed to connect the stabilizer to the mains voltage; pin 3 is for grounding; conclusions 4, 5 - are designed to connect the load to the output voltage of the stabilizer. Regulating transformer 6 is designed for discrete regulation of the output voltage. The winding 7 is connected to the output terminals 4, 5 of the output voltage of the stabilizer. The adjustment winding 8 is connected to the switching contacts of the electromagnetic relay 9. The switched contacts of the relay 9 are connected to the output of the winding 7 connected to the output terminal 4 of the stabilizer, and are also connected to the normally open switched contact of the relay 10. Relays 9, 10 also include switching means - connecting and disconnecting the power circuits of their windings, for example, transistor switches, the control inputs of which are connected to the output of a microprocessor device 11, designed to control switching means and power circuits of the windings of all relays. The input of the microprocessor device 11 is connected to the output of the means for controlling the input voltage and generating a normalized signal 12, compatible in level with the input of the device 11. The inputs of the means for controlling the voltage 12 are electrically connected to the input terminals of the stabilizer through electric circuits connected to the input terminals of the stabilizer, and located up to input terminals of the contact system of the electromagnetic relay of protection against prolonged high voltages.

The node for protection against prolonged high voltages 13 contains an electromagnetic relay for protection against long-term increased voltages 14 with normally open contacts to disconnect the input circuits of the regulating transformer from the network at unacceptable long-term increased voltages. The input of the contact system of the relay for protection against long-term increased voltages 14 is also the input of the node for protection against long-term increased voltages 13 and is connected to the input of the stabilizer - terminals 1, 2 through the node for protection against short-term surge surges 18.

The node for protection against short-term surge surges is made in the form of a parallel voltage limiter on varistors and arresters, connected to pins 1, 2 and pin 3 for grounding.

The power source of the electromagnetic relay for protection against prolonged high voltages and a microprocessor-based device for controlling the switching power supply circuits of the relay windings contains an additional step-down transformer 15, a rectifier with voltage stabilizer 16 for powering the myth processor and the said electromagnetic relay for protection against long-term increased voltages. The power circuit of the winding of the relay of protection against prolonged high voltages 14 is connected to the output of the aforementioned microprocessor device, which generates a switch-off signal for this relay when the current value of the input voltage of the network exceeds an acceptable level.

The input of the additional step-down transformer 15 through the protection means 17 of the transformer 15 against overheating is connected to the output of the protection unit against short-term surge surges 18, and the input of the latter is connected to the input terminals 1, 2 for connecting the stabilizer to the electric network.

The stabilizer works as follows.

When the voltage supplied to the input 1, 2 of the stabilizer, not exceeding the permissible, relay contacts 14 are closed. The input voltage is supplied to the control transformer 6 and the control elements 9-13.

The regulation of the output voltage is carried out by switching the terminals of the winding 8 by the contacts of the relay 9 after closing the switching contact with the normally open contact in the relay 10, and, if necessary, the output voltage is increased or decreased at the output of the stabilizer - terminals 4, 5.

.i / fB When the mains voltage deviates from the nominal voltage by analog signals from the input voltage control means 12 in the microprocessor device 11, a control signal is generated for switching the power supply circuits of the relay windings 9, 10. Analog-to-digital converters of the microprocessor control device 11 convert signals proportional to the voltage into digital form. In the microprocessor device 11, the effective voltage values are determined by software, the result is compared with the corresponding set value, and electromagnetic relay control signals are generated.

Next, the corresponding relays with means for switching the power circuits of their windings switch the necessary conclusions of the transformer windings. As a result of this, the voltage at the output terminals 4, 5, connected to the winding 7 of the transformer b, is discretely changed to the required value, within the limits of permissible capacities. By the switching contacts of the relay 9, the winding 8 is connected to the winding 6 in phase or out of phase, creating a voltage lower or higher relative to the input.

When the nominal voltage of the network is restored, the process is repeated and completed by reverse contact switching.

In the initial state, at rated voltage, through normally closed relay contacts 9, 10, voltage 4, 5 is output from input 1, 2 without using winding 8.

When the input voltage rises, the mythoprocessor device 11 controls the output voltage by closing the switching contact with the normally open contact in relay 10, and through the normally closed contacts of relay 9, winding 8 is connected to winding 7. In this case, current flows from input 1, 2 through the protection unit from short-term pulse overvoltages 18, through the closed contacts of the relay 14, and the contacts of the relay 10 along the windings 7, 8, connected in this case according to the circuit of a step-down autotransformer; the voltage at the output of the stabilizer 4, 5 is reduced to an acceptable level.

When the input voltage is reduced by the microprocessor device 11, the output voltage is regulated by closing the switching contact with the normally open contact in the relay 10, and by switching the switching contacts with the normally open contacts to the relay 9, through these contacts of the relay 9, the winding 8 is connected to the winding 7 in the opposite polarity. In this case, the current flows through the windings 7, 8, connected in this case according to the circuit of a step-down autotransformer. Due to this, the voltage at the output of the stabilizer - conclusions 4, 5, - rises to the required level.

The number of switched control steps, regulating windings of the transformer and, accordingly, relays, switching outputs of the transformer windings, as well as the necessary means for switching the power circuits of the windings of these relays, can be any. Additional transformer windings can be either insulated or connected to each other, forming an autotransformer with taps.

With significant overvoltages between pins 1, 2 or ground terminal 3 and pins 1, 2, the corresponding arresters and varistors of the protection node against short-term pulse surges 18 are triggered.

If the current value of the input voltage of the acceptable level is exceeded for a long time, the myth-processing device 11 turns off the power of the winding of the protection relay from prolonged high voltages 14, the contacts of which open and the regulating transformer is disconnected from the network. After the termination of the effects of dangerous long-term increased voltages, the myth-processing device 11 again turns on the power of the winding of the protection relay against long-term increased voltages 14, the contacts of which are closed and the regulating transformer is connected to the network, automatically restoring the on state of the regulating transformer.

the probability of failure of the stabilizer and the load connected to it during overvoltages caused by the following reasons: lightning discharges, surges on power lines or substations, electric vehicles and other reasons.

This technical solution can be used in AC voltage stabilizers for communication equipment, computer equipment, for domestic and industrial installations.

Sources of information.

1. RF patent No. 2119229, IPC6 Н02М 5/12, G05F 1/253. A method of regulating voltage under load and a device for its implementation.

2. RF patent No. 2133977, IPC6 G05F 1/20. The method of switching branches of the transformer winding and a device for its implementation.

3.Useful model No. 18810, MPK7 Н02М 2/22, 5/12. Device for stepwise regulation of alternating voltage.

4. RF patent No. 2188496, IPC7 Н02М 5/12, G05F 1/30. Device for stepwise regulation of alternating voltage.

5.Useful model No. 8847, MPK6 Н02М, 5/22. AC voltage stabilizer.

6. US patent No. 5726561, IPC6 G05F, 1/16. Voltage selection apparatus and methods.

Claims (1)

1. An AC voltage stabilizer with overvoltage protection, containing input terminals for connecting the stabilizer to an unstabilized voltage source, stabilized voltage output terminals for connecting a load, input voltage control means, an adjustment transformer having several windings with switched terminals for regulating the output voltage, electromagnetic output voltage control relays, to the contact systems of which are connected switched outputs odes of the windings of the regulating transformer, a microprocessor-based device for controlling the switching of the power supply circuits of the windings of the output voltage control relay, which contains input terminals connected to the input voltage control means and output terminals connected to the control circuit of the power supply windings of the electromagnetic output voltage regulation relay, characterized in that in addition two nodes of the stabilizer protection against increased voltages at its input have been introduced: the short-circuit protection unit pulse surge voltage, in which the duration of one pulse does not exceed the duration of the half-cycle of the mains supply voltage, a node for protection against prolonged high voltages, for which the effective value of the input voltage of the network exceeds the set maximum permissible value, while the node for protection against short-term surge voltage contains voltage limiting elements, made on varistors and arresters, and the protection unit against prolonged high voltages contains an electromagnetic protection relay from prolonged overvoltages with normally open contacts to disconnect the input circuits of the regulating transformer from the network during unacceptable overvoltages, the power supply of the mentioned electromagnetic relay for protection against prolonged overvoltages and a microprocessor-based device for controlling the switching of power supply circuits of the relay windings, containing an additional step-down transformer, rectifier and voltage regulator for microprocessor power supply and said electromagnetic surge protection relay moreover, the power circuit of the winding of the relay of protection against prolonged high voltages is also connected to the output of the aforementioned microprocessor device, which generates a signal to turn off this relay when the current value of the input voltage of the network exceeds the permissible level, while the input terminals of the stabilizer are electrically connected to the input circuits of the regulating transformer of the stabilizer through series-connected surge protection node and contact system of the electromagnetic protection relay against high voltage exceeding the permissible level of the current value of the mains voltage, and the input circuit of the additional step-down transformer of the protection unit is electrically connected to the input terminals of the stabilizer by connecting to the circuits located between the input terminals of the stabilizer and the input of the contact system of the electromagnetic relay of protection against prolonged high voltage, microprocessor device, in addition to the control circuit of the power supply of relay windings designed for adjusting output voltage circuit contains the following circuits: a circuit for calculating the effective value of the input voltage of the network, a circuit for detecting an excess of the input voltage of the maximum permissible value of the voltage and a control circuit for turning off the power of the protection relay against prolonged high voltages when the microprocessor detects that the input voltage exceeds the maximum permissible voltage the value of the actual voltage value, which ensures emergency shutdown of the circuit power regulating transformer from a dangerous high voltage present on the input terminals of the stabilizer.