CN2457711Y

CN2457711Y - Power transformer

Info

Publication number: CN2457711Y
Application number: CN 00246350
Authority: CN
Inventors: 黄来
Original assignee: Huada Motor Factory Co ltd
Current assignee: Huada Motor Factory Co ltd
Priority date: 2000-08-14
Filing date: 2000-08-14
Publication date: 2001-10-31
Anticipated expiration: 2010-08-14

Abstract

The utility model relates to a power transformer, which comprises a main winding connected with the output, an excitation winding used for changing output voltage of the main winding, a voltage sensing device used for comparing input voltage and the prearranged voltage value, and a switching device used for electrically connecting the excitation winding and a power supply. The transformer can enable the excitation winding to automatically change a first state of the output voltage of the switching device according to the comparison result provided by a voltage sensor to convert with a second state that the excitation winding operates independent with the voltage sensor in the second state.

Description

A kind of power transformer

The utility model relates to a kind of power transformer, relates in particular to the power transformer with bistable pressure and buck functionality.

Power transformer is an indispensable equipment of each stage of electric power transfer.In order to have good efficiency of transmission, electric power is transferred to the terminal use by very high-tension electrical network from generator usually.Conventional transmission voltage has the voltage of several ten thousand volts, and the normally used voltage of terminal use is usually in the scope of several hectovolts.Therefore, this very high-tension electric power must at first be done the step-down conversion by a power transformer before by most of industry or civilian users use.

Although the use of electric energy has become modern society and has continued phenomenon for a long time, in many countries because the stability of a variety of causes generating and electric power conveying still can not be satisfactory.This instable main consequence is the long-term or short-term fluctuation of user side supply voltage, and it causes non-optimum performance, low-power coefficient, intermittent fault and the premature damage to installing such as machine, equipment and electrical appliance etc.The user who is connected on these electrical networks must rely on voltage stabilizing transformer usually to provide the stabilized supply voltage environment to its equipment, and its equipment can be operated under the supply voltage stable power-supplying environment consistent with the rated voltage of equipment.

In addition, all right electrification transformer of terminal use is reduced to various bucking voltages by the power supply department after the equipment installation with supply voltage, mates with the rated voltage range with the consumer electronics articles for use.And, well-known by electrical appliance being connected to a power supply a little less than its rated voltage, can electrical appliance be worked more economically.

Traditional voltage stabilizing transformer generally includes a voltage stabilizing circuit that is series at Transformer Winding.The major defect of this kind voltage stabilizing transformer is that maintenance or repairing voltage stabilizing circuit are then powered and will be interrupted if desired.Both made for three-phase transformer and had only the voltage stabilizing circuit of a phase to be affected, also had the problem of power failure.

Therefore need provide a kind of improved regulated power transformer, make that voltage stabilizing circuit was removed also can keep power supply to the power supply user.Preferably, the improved transformer of this kind need not voltage stabilizing and also can work when main power supply is stablized.Preferably, a kind of improved three-phase transformer with above-mentioned feature should be able to independently be adjusted each with the phase calibration imbalance.Therefore, the purpose of this utility model is to realize above-mentioned target.At least, providing a kind of useful selection of voltage stabilizing transformer to the public is the purpose of this utility model.

A kind of power transformer that provides according to the utility model comprises that a main winding that is used to export connection, one are used to change excitation winding by the output voltage of described main winding, one and are used for input voltage voltage sensor and conversion equipment that is used to be electrically connected described excitation winding and power supply with the scheduled voltage comparison.This power transformer is characterised in that described transformer can switch between first and second kinds of states; Its described conversion equipment is suitable for making described excitation winding change output voltage automatically according to the predetermined voltage judgment value corresponding to the comparative result that is provided by voltage sensor described in first kind of state; And its described excitation winding is independent of the described voltage sensor operation in second kind of state.

Preferably, conversion equipment is applicable to and connects described excitation winding to increase or to reduce output voltage.

Preferably, described excitation winding comprises a winding with variable pitch of the laps number.

Brief description of drawings

Fig. 1 represents to be higher than according to being connected to of the utility model first embodiment the schematic diagram of the single-phase transformer of nominal voltage input;

Fig. 2 represents to be connected to the schematic diagram of the embodiment shown in Figure 1 that is lower than the nominal voltage input;

Fig. 3 represents to be connected to the schematic diagram of the embodiment shown in Figure 1 of nominal voltage input;

Fig. 4 represents that central input voltage is lower than nominal voltage corresponding to the schematic diagram of the embodiment shown in Figure 1 of reserve operating state;

Fig. 5 represents that central input voltage is higher than nominal voltage corresponding to the schematic diagram of the embodiment shown in Figure 1 of reserve operating state; And

Fig. 6 represents the schematic diagram according to the three-phase transformer of the utility model second embodiment.

The detailed description of preferred version

Referring to figs. 1 through Fig. 4, show first embodiment of single-phase transformer of the present utility model.This comprises voltage sensor of transformer 10, conversion equipment 20, voltage regulating device 30 and circle single-phase transformer winding 40 on the iron core 50.Transformer Winding 40 comprises main winding R1, a R2 and excitation winding R3, a R4.Excitation winding the port of this winding have first end 31 and second end 32 and between first and second ends, have a plurality of in the middle of the output taps.Total effectively number of windings in the excitation winding will be exported the choice device 33 that tap is connected in the power supply input lead accordingly by one and determine.

But main winding R1, R2 and excitation winding R3, R4 are on a magnetic flux iron core 50, consequently by excitation winding R3, R4 magnetic flux that produces and the magnetic field interaction that is produced by main winding.To increase or reduce according to magnetic polarity corresponding to total output voltage of total synthetic magnetic field of main winding and then main winding corresponding to excitation winding R3, the R4 of the magnetic polarity of main winding R1, R2.Main winding comprises that preferentially a plurality of windings in parallel are to satisfy the output of big electric current or to require the situation of a plurality of outputs.In the present embodiment, an end 41 of main winding is connected with power supply, and the other end 42 is connected with output.But it is it should be noted that the main winding in another bobbin of Transformer Winding can only be connected with output, thereby independent with input.

Voltage sensor 10 comprises having input voltage and scheduled voltage comparison and send the voltage sensing device of commands for controlling conversion equipment 20.

Excitation winding end

31,32 can be connected with zero line to produce the magnetic field corresponding to first polarity of main winding with the live wire of power supply by conversion equipment 20.Conversion equipment 20 comprises a plurality of change-over circuits, and these change-over circuits are suitable for first and second ends of excitation winding and live wire are linked to each other with zero line with the magnetic field that produces above-mentioned first polarity or the magnetic field of opposite polarity.In addition, conversion equipment also is suitable for excitation winding and main winding are carried out the magnetic isolation.Therefore, conversion equipment determines which bar lead each winding terminal is physically connected to, and therefore live wire or zero line have also determined the relative direction that the electric current between main winding and excitation winding flows.By putting upside down the annexation of end one line, the relative direction that the electric current in main winding and excitation winding flows is reversed and has changed the total synthetic magnetic flux in the iron core thus.Conversion equipment also can switch to backup status with transformer, controlled by voltage sensor in the connection of this state excitation winding.

Transformer works in two kinds of main states: automatic stabilisation state and backup status, they can be selected by state converter 60.The operation principle of transformer under the auto state below is described.

With reference to figure 1, when voltage sensor senses to surpassed the supply power voltage of the predetermined upper limit, for example the system for rated voltage 220V was 229V, and it reduces being connected of output voltage with the instruction transformation device between excitation winding and supply lines.Finish this process by the configuration that conversion equipment 20 is switched to as shown in Figure 1.In this configuration, conversion equipment is connected excitation winding automatically in the represented mode of dotted line among Fig. 1 with supply lines.This kind connection can make total synthetic magnetic field of main winding and excitation winding cause and maximum voltage drop by main winding obtain required voltage drop thus.In another program, output voltage can further reduce by excitation winding is connected in output.With this connected mode, output voltage will further reduce by the effect of closing of main winding and excitation winding, and produces the further decline of output voltage.The actual situation line is depicted as the rising potential circuit among Fig. 1.

With reference to figure 2, when voltage sensor senses to was lower than the supply power voltage of predetermined lower bound, for example the system for rated voltage 220V was 211V, and it improves the instruction transformation device connection of output voltage.Finish this process by the configuration that conversion equipment is switched to as shown in Figure 2.In this configuration, conversion equipment is connected excitation winding automatically in the represented mode of dotted line among Fig. 2 with supply lines.In this kind connection, the relative current opposite in direction in the relative sense of current in the excitation winding and Fig. 1 configuration, and the total synthetic magnetic field that main winding and excitation winding produce will cause that the maximum voltage by main winding raises, and obtains required voltage thus and raises.The actual situation line is depicted as the drop-out voltage circuit among Fig. 2.

In the configuration of above-mentioned Fig. 1 and Fig. 2, the actual change amount of output voltage can realize accurate adjustment by total number of windings that selector installation adjusting excitation winding is set approx.

With reference to figure 3, when the supply power voltage of voltage sensor senses in preset range, for example for the system of rated voltage 220V be 211.2V to 228.9V, do not propose stability requirement and excitation winding and main winding carried out magnetic isolate so that main winding is not subjected to the magnetic influence of excitation winding.Finish this process by the configuration that conversion equipment is switched to as shown in Figure 3.In this configuration, conversion equipment links together a plurality of excitation winding ends automatically in the represented mode of dotted line among Fig. 3, and excitation winding will not produce any significant magnetic field that can influence output voltage.The actual situation line is depicted as the weighing apparatus volt circuit among Fig. 3.In the present embodiment, the more excellent pass of matching of main winding and excitation winding is that supply power voltage can be raise in approximate 4% scope by the influence of what excitation winding or reduce.

When voltage stable circuit needs repairing or stable so that when no longer needing voltage stable circuit, the backup status that transformer can be switched to is as shown in Figure 4 and Figure 5 carried out work when supply power voltage.Under this kind state, excitation winding is connected to the power supply input by conversion equipment and no longer is subjected to the control of voltage sensor.In this programme, excitation winding preferentially is connected to input in the represented mode of dotted line.In this connected, the relative current flow between excitation winding and main winding was identical with the relative current flow among Fig. 1, and output voltage will be less than input voltage.Under backup status, preferentially according to known to usually under the supply power voltage more lower slightly, can make electrical appliance than rated voltage more economically and the mode of not sacrificing its performance connects, for example than rated voltage lower slightly 4%.On the other hand, if require output voltage than input voltage height,

input

31,32 modes best and that Fig. 4 is same of excitation winding are connected in the input power supply.The actual situation line is depicted as regulation voltage decline circuit among Fig. 4, and the actual situation line is depicted as voltage rising circuit among Fig. 5.

Figure 6 illustrates second embodiment of the present utility model of three-phase transformer.In this scheme, three-phase transformer comprises the unidirectional transformer of three independently above-mentioned first schemes, and each corresponding linking to each other of each unidirectional transformer and three phase mains.According to each feature of assembly transformer, the feature of three-phase transformer is identical with above-mentioned feature.

The advantage that has the above-mentioned transformer of backup status is, because the single-phase transformer of combination can raise or reduce output voltage, improves the output of three-phase voltage balance thereby can regulate.When the voltage of this area stable but still one among a small circle in fluctuation, for example 4% o'clock, such transformer was still useful in future.When such, the automatic voltage conditioning equipment can be stopped using and also no longer need and safeguard.The further significant advantage of the three-phase transformer of this single-phase transformer unit that has an independent adjusting is to reduce because electric quantity loss that imbalance of three-phase voltage causes, thereby can make energy-saving effect more remarkable.

Although the transformer with reference to a specific winding mode is illustrated the utility model, for the researcher in this field, other Transformer Winding form that the utility model can be applied to suitable alternative is conspicuous.

Claims

1, a kind of power transformer comprises that is used for the main winding that out-put supply connects, one is used for by the excitation winding of magnetic coupling change by the output voltage of described main winding, one is used for voltage sensing device that input voltage and scheduled voltage are compared, and one be used for the conversion equipment that is electrically connected between described excitation winding and power supply, it is characterized in that: described excitation winding and main winding are wrapped on the common magnetic core, described excitation winding is electrically connected with the power supply input by described conversion equipment, this conversion equipment comprises the device with respect to the magnetic flux of the magnetic flux of main winding that changes excitation winding, thereby regulates the output voltage by described main winding.

2, require 1 described a kind of power transformer according to profit, it is characterized in that, described excitation winding comprises a plurality of tap outputs, and this tap output is corresponding to the different numbers of turn of described excitation winding, and this excitation winding is connected with the power supply input by tap output.

3, a kind of power transformer according to claim 1 is characterized in that, described conversion equipment includes the device that changes by the sense of current of excitation winding.

4, a kind of power transformer according to claim 1 is characterized in that, described main winding comprises many groups winding in parallel.

5, a kind of power transformer according to claim 1, it is characterized in that, one selector installation is connected between described excitation winding and the input of described power supply, and described selector allows the concrete tap output on the described excitation winding to select to be connected with described power supply input.

6, a kind of power transformer according to claim 1 is characterized in that, the input of described excitation winding links to each other with the output of described main winding.

7, a kind of power transformer according to claim 1 is characterized in that, described transformer is that each of a three-phase transformer and described transformer all has independent conversion equipment mutually.

8, a kind of power transformer according to claim 7, it is characterized in that each described transformer includes that independently excitation winding and selector installation select the magnet exciting coil number of turn of each excitation winding to be connected to the power supply input to be independent of other excitation transformers.