KR102349935B1 - Apparatus and Method for Supplying Power to Semiconductor Transformer - Google Patents

Abstract

Disclosed are a power supply device for a semiconductor transformer, and an operating method thereof. According to one aspect of the present invention, the power supply device for supplying power to a primary side control unit of a semiconductor transformer comprises: an input unit receiving high voltage from primary side capacitors included in a primary side circuit of the semiconductor transformer; a transformer unit lifting input voltage; and an output unit supplying the power to the primary side control unit based on the lifted voltage.

Description

Semiconductor transformer power supply and operating method thereof

Embodiments of the present invention relate to a power supply device for supplying power to a primary-side control unit of a semiconductor transformer and an operating method thereof.

The content described in this section merely provides background information on the present invention and does not constitute the prior art.

In the past, the power conversion system of railway vehicles consisted of a transformer, a secondary side AC/DC converter, and a secondary side DC/AC inverter. The transformer receives a voltage of 60Hz, 25kV through a catenary, and lowers it to about 1kV~3kV. An AC/DC converter connected to the secondary side of the transformer converts an AC voltage of several kV into a DC voltage. Then, the DC/AC inverter rotates the motor of the railway vehicle using the power supplied from the AC/DC converter.

These transformers and AC/DC converters are the parts that take up the most load among the components in railway vehicles. In particular, since the transformer operates at a low frequency of 60 Hz, the value of inductance required for impedance matching is inevitably increased. In order to increase the inductance of the transformer, a lot of windings of the transformer or a lot of iron core must be used, so there are problems that the weight and volume are large and the power density is relatively low.

In order to reduce the volume and weight of the transformer, research on a transformer that uses a semiconductor device to increase the operating frequency of the transformer to more than 60 Hz has been conducted. Specifically, a device that converts an input of a low frequency and high voltage into a high frequency output using a semiconductor device and converts the high frequency output into a voltage required for a railway vehicle through a high frequency transformer has been studied. This is called a solid-state transformer or an intelligent transformer.

Semiconductor transformers utilize power electronics technology to use higher frequencies than transformers in the existing commercial frequency band, which is advantageous for miniaturization and weight reduction. has a

1 is a diagram illustrating a state in which a semiconductor transformer is applied to a railway vehicle.

Referring to FIG. 1 , a catenary 100 and a plurality of semiconductor transformers 110 , 120 , 130 are shown. The plurality of semiconductor transformers 110 , 120 , and 130 include a first semiconductor transformer 110 , a second semiconductor transformer 120 , and an n-th semiconductor transformer 130 . The first semiconductor transformer 110 includes a primary-side converter 112 , a primary-side inverter 114 , a transformer 116 , and a secondary-side converter 118 .

The catenary 100 supplies a high voltage AC voltage. For example, the catenary 100 can supply power at 60 Hz and 25 kV.

The plurality of semiconductor transformers 110 , 120 , 130 converts high AC power of 25 kV supplied from the catenary 100 into DC power and outputs the converted power. The converted DC power is used for the operation of railway vehicles.

Specifically, the primary-side converter 112 converts the AC power of the catenary 100 into DC power when the voltage is input in a divided state by the number of serially connected semiconductor transformers. The primary-side inverter 114 converts the DC power converted by the primary-side converter 112 into high-frequency AC power. When the high-frequency AC voltage of the primary-side converter 112 is input to the primary side of the transformer 116 , the transformer 116 steps-down or boosts the voltage by the turns ratio. The secondary-side converter 118 converts the secondary-side high-frequency AC voltage of the transformer 116 into a DC voltage and then transmits it to the power bus.

In this case, the plurality of semiconductor transformers 110 , 120 , and 130 have input terminals connected in series to each other to receive the input by dividing the AC voltage supplied from the catenary 100 . This is to reduce the voltage stress caused by the plurality of semiconductor transformers 110 , 120 , and 130 by the catenary 100 . In addition, the output terminals of the plurality of semiconductor transformers 110 , 120 , and 130 are connected in parallel to each other to share the output power and output to a power bus (Train Bus). This is to reduce the current stress by dividing the electric power by 1/n when the plurality of semiconductor transformers 110 , 120 , and 130 supply electric power required for driving the railway vehicle.

At this time, a power supply device for supplying power to the primary side of the plurality of semiconductor transformers 110 , 120 , 130 is required. Specifically, there is a need for a power supply for supplying power to a control unit that controls the components of the primary circuit.

The conventional power supply device for supplying power to the primary-side control unit receives power from outside the primary-side circuit. However, since it must be connected to an external component, it is difficult to satisfy the high voltage characteristics and insulation conditions of the primary circuit, and there are problems in that the size of the product increases.

As one of the measures to solve this problem, the 'control power supply of a semiconductor transformer' is disclosed in Korean Registration Publication No. 2094832. In the above document, a configuration for wirelessly supplying external power to a controller for controlling an AC/DC converter is described.

Embodiments of the present invention are not connected to the secondary circuit or the outside of the semiconductor transformer by receiving power from the primary circuit of the semiconductor transformer and supplying power to the primary control unit, thereby improving the dielectric strength condition and reducing the size and cost An object of the present invention is to provide a power supply device and a method for operating the same.

Another embodiment of the present invention provides a power supply device capable of stably supplying power to a primary-side control unit by independently receiving power from a plurality of capacitors included in a primary-side circuit of a semiconductor transformer, and an operating method thereof It has a purpose to provide.

Another embodiment of the present invention is connected only to the primary circuit of the semiconductor transformer, and thus is insulated from the secondary circuit to which a low voltage is applied, thereby providing a power supply for safety such as spark prevention.

According to an aspect of the present invention, there is provided a power supply device for supplying power to a primary-side control unit of a semiconductor transformer, comprising: an input unit receiving a high voltage from primary-side capacitors included in a primary-side circuit of the semiconductor transformer; a transformer for stepping down the input voltage; and an output unit for supplying power to the primary-side control unit based on the step-down voltage.

According to another aspect of this embodiment, there is provided an operating method of a power supply device for supplying power to a primary-side control unit of a semiconductor transformer, the method comprising: receiving a high voltage from primary-side capacitors included in a primary-side circuit of the semiconductor transformer; step-down the input voltage; and supplying power to the primary-side control unit based on the step-down voltage.

As described above, according to an embodiment of the present invention, by supplying power to the primary control unit by receiving power from the primary side circuit of the semiconductor transformer without being connected to the secondary side circuit or the outside of the semiconductor transformer, the dielectric strength condition is reduced can be improved and reduced in size and cost.

According to another embodiment of the present invention, by independently receiving power from a plurality of capacitors included in the primary circuit of the semiconductor transformer, it is possible to stably supply power to the primary control unit.

According to another embodiment of the present invention, by being connected only to the primary circuit of the semiconductor transformer, it is insulated from the secondary circuit to which a low voltage is applied, thereby ensuring safety such as spark prevention.

1 is a diagram illustrating a state in which a semiconductor transformer is applied to a railway vehicle.
2 is a diagram illustrating a conventional power supply device receiving power from a secondary circuit of a semiconductor transformer.
3 is a diagram illustrating a power supply device receiving power from a primary-side circuit of a semiconductor transformer according to an embodiment of the present invention.
4 is a configuration diagram illustrating the components of a power supply device according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same components are given the same reference numerals as much as possible even though they are indicated on different drawings. In addition, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In addition, in describing the components of the present invention, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the component from other components, and the essence, order, or order of the component is not limited by the term. Throughout the specification, when a part 'includes' or 'includes' a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated. . In addition, terms such as '~ unit' and 'module' described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software or a combination of hardware and software.

2 is a diagram illustrating a conventional power supply device receiving power from a secondary circuit of a semiconductor transformer.

Referring to FIG. 2 , the primary side circuit 200 , the primary side switching unit 202 , the primary side capacitors 204 , the transformer 210 , the secondary side circuit 220 , the secondary side switching unit 222 , 2 The secondary capacitors 224 , the control unit 230 and the power supply unit 240 are shown. One semiconductor transformer includes a primary side circuit 200 and a secondary side circuit 220 .

The primary-side converter and the primary-side inverter of the semiconductor transformer in FIG. 1 may include a primary-side switching unit 202 and primary-side capacitors 204 in FIG. 2 . Also, the secondary-side inverter may include a secondary-side switching unit 222 and secondary-side capacitors 224 .

The primary side switching unit 202 receives a high AC voltage from a catenary, stores energy in DC form in the primary side capacitors 204, and converts the DC energy stored in the primary side capacitors 204 back to AC type. It is a component that transmits to the transformer 210 .

The first switching unit 202 is connected in series to the catenary to divide the voltage of the catenary by the number of semiconductor transformers to be applied, and the second switching unit 222 is connected to the transformer 210 to the secondary side of the transformer 210 . voltage is applied Specifically, the first switching unit 202 switches the voltage applied from the catenary according to the switching signal transmitted from the control unit 230 , and the second switching unit 222 according to the switching signal transmitted from the control unit 230 . The voltage applied from the transformer 210 is switched.

Each of the switches constituting the first switching unit 202 and the second switching unit 222 may be a metal oxide semiconductor field effect transistor (MOSFET) switch or an insulated gate bipolar transistor (IGBT) switch. Here, when each of the switches is a MOSFET switch, a diode may be electrically connected between a source and a drain of the MOSFET switch.

The primary side switching unit 202 and the secondary side switching unit 222 may use a plurality of switches and diodes to form a full bridge or half bridge structure. Specifically, it means configuring a circuit in such a way that each diode in a typical full bridge or half bridge structure is replaced with a switch including a parallel diode or a separate diode connected in parallel with a switch .

The primary-side capacitors 204 are components that store the input voltage of the primary-side circuit 200 , and are components that store energy in a high voltage state. On the other hand, the secondary-side capacitors 224 are components that store energy in a relatively low voltage state. For example, each of the primary-side capacitors 204 may be charged with a voltage of 1250 V, and each of the secondary-side capacitors 224 may be charged with a voltage of 15 V.

The transformer 210 is a component that steps down or boosts the AC voltage input from the primary circuit 200 and outputs it to the secondary circuit 220 .

The transformer 210 may further include an inductor on the primary side or the secondary side.

The secondary-side switching unit 222 is a component that receives an AC voltage from the transformer 210 and converts the AC voltage into a DC voltage through the secondary-side capacitors 224 . That is, the DC voltage is stored in a low voltage state in the secondary capacitors 224 .

Finally, the secondary circuit 220 transmits the converted DC voltage to the driving motor.

The control unit 230 is a component that controls switches included in the primary side switching unit 202 . Also, the control unit 230 may further include a sensing control unit that senses voltages or currents of nodes in the semiconductor transformer.

The controller 230 may include at least one of an Insulated Gate Bipolar Transistor Driver Unit (IDU), a Gate Driver Unit (IDU), and a sensing unit.

The power supply unit 240 is a component that supplies power to the control unit 230 .

As shown in FIG. 2 , the conventional power supply 240 receives power from the secondary circuit 220 rather than the primary circuit 200 to supply power to the controller 230 . Otherwise, the power supply unit 240 receives power from the outside of the semiconductor transformer.

This is because a high voltage is applied to the primary side circuit 200 . Since the input of the primary circuit 200 is an AC voltage of 25 kV, which is the power supply voltage of a railway vehicle, the dielectric breakdown voltage of the elements of the primary circuit 200 must be 70 kV or more. That is, when the power supply unit 240 receives the high voltage of the primary side circuit 200 , it must have an insulating strength capable of withstanding the high voltage, thereby increasing the size and cost. Specifically, a separate converter for controlling the voltage of the catenary is required, and even in this case, a control power source for the separate converter is required, so that a voltage distribution circuit for low power needs to be additionally configured.

Accordingly, the power supply 240 generally receives a relatively low voltage compared to the voltage applied to the primary circuit 200 to supply power to the control unit 230 .

3 is a diagram illustrating a power supply device receiving power from a primary-side circuit of a semiconductor transformer according to an embodiment of the present invention.

Referring to FIG. 3 , the primary side circuit 200 , the primary side switching unit 202 , the primary side capacitors 204 , the transformer 210 , the secondary side circuit 220 , the secondary side switching unit 222 , 2 The secondary capacitors 224 , the controller 230 and the power supply 300 are shown.

Primary side circuit 200 , primary side switching unit 202 , primary side capacitors 204 , transformer 210 , secondary side circuit 220 , secondary side switching unit 222 , secondary side capacitors 224 . and the control unit 230 are the same as those described in FIG. 2 .

On the other hand, the power supply device 300 according to an embodiment of the present invention receives power from the primary-side capacitors 204 and supplies power to the control unit 230 . Since the voltage used by the controller 230 is a low voltage, and the charging voltage of the primary side capacitors 204 is a very high voltage, the power supply 300 is a DC/DC converter or SMPS (Switching Mode Power) that lowers the high voltage to a low voltage. supply).

Specifically, the power supply 300 receives a high voltage from the primary capacitors 204 included in the primary circuit 200 of the semiconductor transformer.

According to one embodiment of the present invention, primary side capacitors 204 include primary side top capacitors and primary side bottom capacitors. In FIG. 2 , primary-side upper capacitors may refer to capacitors located between node A and node C, and primary-side lower end capacitors may refer to capacitors located between node C and node E. In FIG. In this case, the power supply device 300 may receive a high voltage from any one of the primary side upper end capacitors and the primary side lower end capacitors.

According to another embodiment of the present invention, the primary-side capacitors 204 include at least two capacitors connected in series, and the power supply device 300 may independently receive a high voltage from the at least two capacitors. . For example, in FIG. 2 , the power supply 300 may receive power from capacitors connected to the node A, the node B, and the node C. The power supply 300 receives an input from three nodes of a series-connected capacitor. That is, the power supply device 300 can supply power to the control unit 230 stably by equally receiving a voltage balance from two capacitors connected in series.

The power supply device 300 steps down the voltage input from the primary side capacitors 204 , and supplies power to the controller 230 based on the step-down voltage. At this time, the input of the power supply device 300 is a high voltage of the primary side capacitors 204 , and the output is a low voltage input to the control unit 230 . The power supply 300 must have high insulation characteristics to withstand the voltage difference between the input and the output.

To this end, according to an embodiment of the present invention, the power supply device 300 includes a transformer therein, and the transformer is a high-frequency transformer in which an enamel wire wrapped with a Teflon tube is wound. can be According to an embodiment of the present invention, the high-frequency transformer winding the enamel wire wrapped with the Teflon tube can increase the dielectric strength between the primary side and the secondary side of the transformer compared to the transformer in which the coil is simply wound.

On the other hand, according to another embodiment of the present invention, the power supply 300 has an input terminal connected to the primary capacitors and an output terminal connected to the primary control unit, thereby electrically not connected to the secondary circuit as a low voltage unit and the outside. It is separated and has the same dielectric strength as the dielectric strength condition of the primary circuit 200 itself, and it is possible to significantly lower the dielectric strength required for safety. Specifically, the power supply 300 is connected only to the primary circuit 200 , and is not connected to the secondary circuit 220 or the outside. Since the power supply device 300 is connected only to the primary circuit 200 , it is possible to prevent a spark due to a voltage difference from occurring, thereby promoting safety.

In addition, since the power supply 300 does not receive power from the secondary side circuit 220 or the outside, it does not require complex components such as a separate low-power voltage distribution circuit, so the power supply device, that is, a semiconductor transformer size and manufacturing cost can be reduced.

4 is a configuration diagram illustrating the components of a power supply device according to an embodiment of the present invention.

Referring to FIG. 4 , an input unit 400 , a transformer 410 , and output units 420 and 430 are illustrated. The output units 420 and 430 may include a first output unit 420 and a second output unit 430 .

The input unit 400 receives a high voltage from primary capacitors included in the primary circuit of the semiconductor transformer. The input unit 400 has three nodes, and may be connected to any one of the primary side upper end capacitors or the primary side lower end capacitors. 3 and 4 , a node A, a node B, and a node C of the input unit 400 may be respectively connected to the nodes A, B, and C of the primary-side capacitors 204 .

The transformer 410 steps down the input voltage. The transformer 410 has a predetermined turns ratio (ie, 1:N, where N is a natural number), and transforms a voltage applied between the primary winding and the secondary winding according to the turns ratio. For example, if the turns ratio of the transformer 410 is 1:N, the equivalent voltage viewed from the primary side to the secondary side is multiplied by 1/N. This is because the voltage applied to the transformer 410 is proportional to the turns ratio.

According to an embodiment of the present invention, in order to increase the dielectric strength, the transformer 410 may be a high-frequency transformer in which an enamel wire wrapped with a Teflon tube is wound.

The transformer 410 may include at least two high-frequency transformers. The transformer 410 receives a high voltage from the input unit 400 , reduces the voltage to a low voltage, and transmits it to the first output unit 420 and the second output unit 430 . In this case, the transformer 410 may transmit different magnitudes of the secondary-side output voltage connected to the first output unit 420 and the second output voltage connected to the second output unit 430 .

The first output unit 420 or the second output unit 430 supplies power to the primary-side control unit based on the step-down voltage. The output voltage/current of the first output unit 420 may be the same as or different from the output voltage/current of the second output unit 430 .

The power supply 300 may transmit an input voltage to two or more outputs through the first output unit 420 and the second output unit 430 .

Although it is described that the above-described processes are sequentially executed, this is merely illustrative of the technical idea of an embodiment of the present invention. In other words, a person of ordinary skill in the art to which an embodiment of the present invention pertains may change and execute the above-described processes without departing from the essential characteristics of an embodiment of the present invention, or perform one or more of the above-described processes. Since it is possible to apply various modifications and variations by executing in parallel, it is not limited to a time-series order.

Meanwhile, the above-described processes can be implemented as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all types of recording devices in which data readable by a computer system is stored. That is, the computer-readable recording medium includes non-transitory media such as ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage device. In addition, the computer-readable recording medium is distributed in a network-connected computer system so that the computer-readable code can be stored and executed in a distributed manner.

In addition, the components of the present invention may use an integrated circuit structure such as a memory, a processor, a logic circuit, a look-up table, and the like. This integrated circuit structure implements each of the functions described herein through the control of one or more microprocessors or other control devices. In addition, the components of the present invention may be specifically implemented by a part of a program or code including one or more executable instructions for performing a specific logical function and executed by one or more microprocessors or other control devices. In addition, the components of the present invention may include or be implemented by a central processing unit (CPU), a microprocessor, etc. that perform respective functions. In addition, the components of the present invention may store instructions executed by one or more processors in one or more memories.

The above description is merely illustrative of the technical idea of this embodiment, and a person skilled in the art to which this embodiment belongs may make various modifications and variations without departing from the essential characteristics of the present embodiment. Accordingly, the present embodiments are intended to explain rather than limit the technical spirit of the present embodiment, and the scope of the technical spirit of the present embodiment is not limited by these embodiments. The protection scope of this embodiment should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present embodiment.

200: primary side circuit 210: transformer
220: secondary circuit 230: control unit
300: power supply

Claims (10)

In the power supply device for supplying power to the primary side control unit of the semiconductor transformer,
an input unit receiving a high voltage from primary side capacitors included in the primary side circuit of the semiconductor transformer;
a transformer for stepping down the input voltage; and
An output unit for supplying power to the primary side control unit based on the step-down voltage
including,
The primary side capacitors include primary side upper end capacitors and primary side lower end capacitors,
The input unit receives a high voltage from any one of the primary side upper end capacitors and the primary side lower end capacitors,
The transformer is a high-frequency transformer in which an enamel wire wrapped with a Teflon tube is wound,
The output unit is connected to the primary control unit,
The primary-side control unit is a power supply that controls the switches included in the primary-side circuit. delete According to claim 1,
The primary side capacitors include at least two capacitors connected in series,
The input unit,
The power supply device, characterized in that each independently receives a high voltage from the at least two capacitors. delete delete In the operating method of a power supply device for supplying power to the primary side control unit of a semiconductor transformer,
receiving a high voltage from primary capacitors included in a primary circuit of a semiconductor transformer;
step-down the input voltage; and
The process of supplying power to the primary control unit based on the step-down voltage
including,
The primary side capacitors include primary side upper end capacitors and primary side lower end capacitors,
The input receiving process is a process of receiving a high voltage from any one of the primary side upper end capacitors and the primary side lower end capacitors,
The step of step-down is a step of step-down the input voltage using a high-frequency transformer wound with an enamel wire wrapped in a Teflon tube,
The power supply is connected to the primary control unit,
The primary-side control unit is an operating method of the power supply to control the switches included in the primary-side circuit. delete 7. The method of claim 6,
The primary side capacitors include at least two capacitors connected in series,
The input process is
A method of operating a power supply, wherein each of the at least two capacitors independently receives a high voltage. delete delete

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