RU18810U1 - DEVICE FOR VARIABLE AC VOLTAGE REGULATION - Google Patents

Description

DEVICE FOR VARIABLE AC VOLTAGE REGULATION

The utility model relates to the field of electrical engineering and can be used to control voltage, in particular, in accurate, high-speed AC voltage stabilizers.

A device for stepwise regulation of AC voltage (discrete executive body of AC voltage regulators), containing input and output terminals, a transformer having a main winding connected to the input terminal and a sectioned winding for lowering and / or raising the voltage, the desoldering of which is connected to the corresponding inputs of the managed switches the outputs of which are combined and connected to the output terminal (see the book Milovzorov VP Discrete stabilizers and voltage shapers. M .: Energoatomizdat, 1986, p. 14, Fig. 1.6).

A disadvantage of the known device is its low reliability, due to the fact that managed switches, due to the finite switching time, especially at high values of switched currents and voltages, when it is necessary to use powerful switches with a longer switching time, cannot provide switching at points of current transition through zero t .e. at low instantaneous current values, and carry out switching at high instantaneous current values. As a result, it burns out and, (Sticking of the working contacts of the relay, usually used as switches, which leads to abnormal control modes and failure of the device as a whole.

The objective of the utility model is to increase the reliability of the device.

The technical result is to reduce the load on managed switches and increase their life.

This result is achieved by the fact that in the device for controlling AC voltage including input and output terminals, a transformer having a main winding connected to the input terminal of the device and a sectioned winding for lowering and / or boosting voltage, the desoldering of which is connected to the corresponding inputs of the managed switches of the first group of switches , managed switches of the second switchgear are introduced, the inputs of which are connected to the corresponding solders of the sectioned winding of the transform a torus, the summing divider, the first and second inputs of which are connected through the first and second keys, respectively, to the outputs of the managed switches of the first and second groups of switches, respectively, and the adder, the first input of which is connected to the input output, the second input to the output of the summing divider, and the output to the output terminal of the device ..

Moreover:

-transformer made in the form of an autotransformer;

-summing divider is made in the form of an autotransformer;

-managed switches are based on a relay;

the first and second keys are based on non-contact semiconductor elements

The adder is made in the form of a transformer.

The utility model is illustrated by means of the drawings, where in FIG. 1 shows a structural diagram of the proposed device, FIG. 2 summing divider made in the form of an autotransformer, FIG. 3 - adder made in the form of a transformer.

A device for controlling AC voltage (Fig. 1) includes input 1 and output 2 terminals, a transformer main 4 winding connected to the input 1 output of the device, a sectioned winding 5 for lowering and / or increasing voltage, with solders 6 which are connected to the inputs of the managed switches 7 of the first groups of 8 switches, the outputs of which are combined, managed switches 9 of the second group of 10 switches, the inputs of which are connected to the solders 6 of the partitioned transformer winding, and the outputs are combined, summarizing I, the first and second inputs of which are connected through the first 12 and second 13 keys, to the outputs of the managed switches of the first 8 and second 10 groups of switches, respectively, and the adder 14 whose first input is connected to the input terminal 1 of the device, the output to the output terminal 2 of the device, and the second input is connected to the output of the summing divider 11. In this case, the adder can be made in the form of a transformer (Fig. 3) having windings 15 and 16.

A device for regulating alternating voltage operates as follows. The input voltage from terminal 1 is supplied to the input of the main 4 windings of the transformer 3. At the solders 6 of the winding 5, a series of values of the alternating voltage are formed with a certain step of regulation. One or two of the values generated on the solders 6 are fed through the keys 12 and 13 to the inputs of the summing divider 11, the output of which forms the average value between the voltages taken from the corresponding solders. Switches 7 and 9 are keys or two or more input switches that are connected and controlled in such a way that at any time to the outputs of the corresponding

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of groups 8 or 10, only one of the taps is connected, that is, sections of the winding 5 are not bridged, and either the two values from the adjacent taps (during voltage switching) or one value from the same one are supplied to the first and second inputs of the summing divider 11 same soldering. From the output of the summing divider 11, an alternating voltage is supplied to the winding 16 of block 14, in this case made in the form of a transformer. Thus, the alternating voltage generated on the winding 15 of the transformer 14 is added or subtracted with the input voltage and supplied to the output terminal 2 of the device.

In steady state, the first and second inputs of the summing divider 11 are connected to the same tap. To change the output voltage carried out during the regulation process, the device enters the switching mode, for which a corresponding control action (for example, in the form of a digital signal or code) is applied to the engaging inputs of the switches 7 or 9. In this case, the corresponding switch group is opened before changing the control code key 12 or 13. Opening is carried out for a half-period of alternating voltage, i.e. for a network with an alternating current frequency of 50 Hz, the key 12 or 13 will remain open for 10 ms from the moment the current passes through zero until the next transition. During this time, the state of the managed switches of the corresponding group of switches is changed, in accordance with the changing control code, so that the switches are switched in an open circuit, which greatly facilitates the mode of operation of the switches. Then, in the same way, another group of switches changes.

When performing a summing divider in the form of an autotransformer (Fig. 2), on the tap of the midpoint of the latter, the arithmetic mean value of the voltages at its inputs is formed.

so if Ugxi and UBx2 are the voltages at the first and second inputs of the summing divider, then the voltage at its output of Others will be equal to:

UBHxi; (UBxl + UBx2) / 2

The maximum voltage between the inputs of the summing divider 11 is limited by the difference in the voltage values of the adjacent solders, and switching along the circuit of the first and second inputs of the summing divider occurs sequentially in time. Thus, the maximum change in the output voltage during switching is possible only within half the voltage difference between the solders.

Transformer 3 can either provide galvanic isolation of the input and output of the device, or be made in the form of an autotransformer.

The use of 12 and 13 non-contact semiconductor elements as keys, for example, transistors, thyristors or triacs, ensures the prompt switching off of the desired circuit for a given half-cycle of a sinusoidal oscillation of the controlled voltage.

The proposed device allows to increase the reliability of the device by eliminating the adverse effects of switching switches under load, allows you to use slower-speed relay switches or use a device-regulator at higher frequencies of controlled alternating voltage.

Claims (6)

1. A device for controlling AC voltage, including input and output terminals, a transformer having a main winding connected to the input terminal of the device and a sectioned winding for lowering and / or increasing voltage, the soldering of which is connected to the corresponding inputs of the managed switches of the first group of switches, characterized in that managed switches of the second group of switches are introduced into it, the inputs of which are connected to the corresponding taps of the sectioned transformer winding, summarized the master divider, the first and second inputs of which are connected through the first and second keys, respectively, to the outputs of the managed switches of the first and second groups of switches, respectively, and the adder, the first input of which is connected to the input output, the second input to the output of the summing divider, and the output to the output device output.  2. The device according to p. 1, characterized in that the transformer is made in the form of an autotransformer.  3. The device according to any one of claim 1 or 2, characterized in that the summing divider is made in the form of an autotransformer.  4. The device according to any one of claims 1, 2 or 3, characterized in that the managed switches are based on a relay.  5. The device according to any one of claims 1 to 3 or 4, characterized in that the first and second keys are made on the basis of non-contact semiconductor elements. 6. The device according to any one of claims 1 to 4 or 5, characterized in that the adder is made in the form of a transformer.