Semiconductor circuit breaker including power semiconductor switch, and power supply device comprising semiconductor circuit breaker

Abstract

The present invention relates to a semiconductor circuit breaker comprising: a semiconductor switch unit which is arranged at an input electric circuit through which current is supplied from a power source to a load, and which includes at least one semiconductor switch for opening or closing the input electric circuit; a control unit, which controls a gate driver of the at least one semiconductor switch so as to control the opening or closing of the input electric circuit; and at least one inductor which is a separate electric circuit from the input electric circuit having the semiconductor switch unit arranged thereon, and which is arranged at a feedback electric circuit through which the current that is output from the load is fed back to the power source.

Description

A semiconductor circuit breaker having a power semiconductor switch and a power supply device including the semiconductor circuit breaker

[0001] The present invention relates to a semiconductor circuit breaker including a power semiconductor switch for controlling power supplied to a load or other system, and a power supply system including a plurality of power sources connected through the semiconductor circuit breaker.

[0002] Conventional mechanical circuit breakers have the problem of requiring a relatively long time of several tens of milliseconds to interrupt the circuit, and during this time, abnormal currents flow into the load. Therefore, power supplies equipped with semiconductor circuit breakers (SSCBs) capable of high-speed current interruption, including switches made of power semiconductors capable of conducting large currents and having high switching frequencies, are emerging. Such semiconductor circuit breakers utilize the power semiconductor switches to electrically interrupt circuit connections, offering the advantage of extremely fast circuit interruption speeds.

[0003] Figure 1 illustrates an example of a power supply circuit equipped with such a conventional semiconductor circuit breaker. Figure 1 (a) illustrates a case where only one semiconductor switch is provided, and Figure 1 (b) illustrates a case where two semiconductor switches are provided.

[0004] First, referring to (a) of Fig. 1, a typical semiconductor circuit breaker can be configured to include a semiconductor switch (12) including a power semiconductor, a gate driver (11) for applying a gate voltage to a gate terminal of the semiconductor switch (12), and a control unit (10) for controlling the gate driver (11).

[0005] The above-described conventional semiconductor circuit breaker may be equipped with an inductor (15) connected in series with the semiconductor switch (12). Here, the inductor (15) is intended to limit the rate of increase (di / dt) of current supplied from a power source to a load, and when an abnormal current such as a leakage current or a short-circuit current occurs, by delaying the time for the amplitude of the abnormal current to reach a maximum value, the load can be disconnected from the power source before the current increased by the abnormal current reaches its maximum value. In addition, by slowing down the rate of increase of the current, the occurrence of the abnormal current can be detected more accurately.

[0006] Meanwhile, the current rise rate can be more significantly limited as the inductance of the inductor (15) increases. Therefore, using an inductor with a large inductance can be more effective. However, the inductance can increase as the cross-sectional area of ​​the core increases and the number of turns of the conductor wound around the core increases. In other words, the larger the inductance is, the higher the protection effect of the load or semiconductor switch (12) or the accuracy of detecting abnormal current can be. Therefore, in order to practically have the effect according to the inductance, the inductor (15) must have a size that is at least a certain size or larger.

[0007] However, as shown in (a) and (b) of Fig. 1, a typical semiconductor circuit breaker has a configuration in which an inductor (15) is connected in front of a semiconductor switch (12), or between a plurality of semiconductor switches (12), or subsequent to the semiconductor switch (12). Since the typical semiconductor circuit breaker has an integrated configuration in which the inductor (15) is connected subsequent to the semiconductor switch (12), there is a problem in that the typical semiconductor circuit breaker becomes large in size due to the volume of the inductor (15) exceeding a certain size.

[0008] In addition, when the semiconductor switch (12) is normally turned on and the power source and the load are electrically connected, the inductor (15) can generate a magnetic field and charge energy. On the other hand, when the semiconductor switch (12) is turned off and the electrical connection between the power source and the load is cut off, the current flow applied to the inductor (15) is stopped, and the magnetic field generated in the inductor (15) can be extinguished. In this case, the extinguished magnetic field induces a current flowing in the opposite direction to the forward current flow. In other words, a counter electromotive force is generated.

[0009] Due to this counter electromotive force, a voltage much greater than the voltage applied to the inductor (15) is instantaneously formed across both terminals of the semiconductor switch (12). In addition, there is a problem that if a spark occurs due to this counter electromotive force, it may damage electronic components connected to the circuit.

[0010] In order to solve the problem of this counter electromotive force, the conventional semiconductor circuit breaker has a separate circuit (20) including at least one resistor between both ends of the semiconductor switch (12), for example, a freewheeling circuit or a flyback circuit. And the counter electromotive force can be eliminated through the separate circuit (20). Therefore, in the case of the conventional semiconductor circuit breaker, there is a problem in that the size increases because it includes not only the semiconductor switch (12) but also an inductor (15) and a separate circuit (20) for eliminating the counter electromotive force.

[0011] The present invention aims to solve the above-mentioned problems and other problems, and provides a semiconductor circuit breaker having a structure that can be arranged more efficiently according to the shape or space in which the circuit is arranged.

[0012] In addition, the present invention aims to provide a more compact power supply system by separating the inductor and the circuit for eliminating counter electromotive force from the semiconductor switch unit in a power supply system having multiple power sources by arranging the inductor in a separate circuit from the circuit in which the semiconductor switch unit is arranged.

[0013] In order to achieve the above or other purposes, according to one aspect of the present invention, a semiconductor circuit breaker according to an embodiment of the present invention is characterized by including a semiconductor switch section which is disposed on an input path through which current is supplied from a power source to the load and includes at least one semiconductor switch for opening or closing the input path, a control section which controls a gate driver of the at least one semiconductor switch to control opening or closing of the input path, and at least one inductor which is disposed on a return path which is separate from the input path through which current output from the load is returned to the power source.

[0014] In one embodiment, the input circuit is characterized in that it is a P (Positive) phase circuit, which is a live line, and the return circuit is a N (Neutral) phase circuit, which is a neutral line.

[0015] In one embodiment, the at least one inductor is characterized in that it is arranged between the output terminal of the load and the power source, and is connected in series with the load at a rear end of the load.

[0016] In one embodiment, the at least one semiconductor switch includes a rectifier element arranged in a direction opposite to the direction in which the semiconductor switch is arranged, wherein the rectifier element includes at least one of a diode, a rectifier, or a thyristor.

[0017] In one embodiment, the semiconductor switch is characterized by being composed of an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

[0018] In one embodiment, the invention further comprises a counter electromotive force elimination circuit for eliminating counter electromotive force generated when current supply is interrupted due to the semiconductor switch being turned off, in a different circuit from the circuit in which the semiconductor switch unit is disposed.

[0019] In one embodiment, the counter electromotive force elimination circuit is characterized by including at least one diode connected to both ends of the inductor disposed in a different circuit from the circuit in which the semiconductor switch unit is disposed, and having a polarity arranged in a direction opposite to the direction in which current flows through the circuit in which the inductor is disposed.

[0020] In one embodiment, a link capacitor is further provided between the input circuit and the return circuit, which is connected in parallel to the power source.

[0021] In one embodiment, the semiconductor switch unit includes first and second semiconductor switches disposed between a first power system and a second power system, connected in series with each other and disposed in opposite directions, wherein one of the first power system and the second power system is a power source that supplies current to the other, and the other operates as a load that receives current from the other.

[0022] In one embodiment, the inductor is a variable inductor capable of changing inductance, and the control unit is characterized in that, when the load is changed, the inductance of the variable inductor is changed so that the total inductance, which is the sum of the inductance of the changed load and the inductance of the variable inductor, forms a preset inductance.

[0023] In one embodiment, the load is characterized as being an inductive load.

[0024] In addition, a power supply system according to an embodiment of the present invention is characterized by including a plurality of semiconductor switch units that connect a plurality of power supplies in parallel, a bus that connects the plurality of power supplies connected in parallel and the load, a control unit that controls gate drivers of each semiconductor switch included in the plurality of semiconductor switch units to control opening or closing of each path through which current is supplied to the bus from each power supply, and a common inductor that is disposed at an output terminal of the load and provides an inductance that is commonly applied to each of the plurality of semiconductor switch units.

[0025] In one embodiment, the invention further comprises a counter electromotive force elimination circuit including at least one diode connected to both ends of the common inductor and having a polarity arranged in a direction opposite to the direction in which current flows through the circuit in which the common inductor is arranged.

[0026] In one embodiment, the first power source among the plurality of power sources includes two or more energy storage devices connected in series, and the semiconductor switch unit disposed between the first power source and the bus is characterized in that it is disposed between the two or more energy storage devices connected in series.

[0027] In one embodiment, the control unit is characterized in that it controls a duty rate, which is a ratio of a time for which the semiconductor switch unit is turned on and a time for which the semiconductor switch unit is turned off, differently for each of the plurality of power sources so that the ratio of the amount of current supplied to the load by each of the plurality of power sources is different.

[0028] According to at least one of the embodiments of the present invention, the present invention has the effect of allowing a semiconductor circuit breaker to be arranged by more efficiently utilizing the shape or space in which the circuits are arranged by separating the inductor from the semiconductor switch portion and placing the semiconductor switch portion and the inductor in different circuits.

[0029] In addition, the present invention has the effect of enabling the use of an inductor having a higher inductance by securing sufficient space for arranging an inductor and enabling the use of an inductor having a large inductance, thereby enabling the implementation of a power supply system in which semiconductor switches connected to a plurality of power sources commonly use a single inductor.

[0030] In addition, the present invention allows an inductor to be placed on a current output line of a load from which current is output, thereby forming an inductance that is the sum of the inductance of the inductor and the inductance of the load. Accordingly, an inductance having a magnitude greater than the inductance of the inductor can be formed, thereby providing an effect of providing a higher load and semiconductor switch protection effect or an abnormal current detection precision.

[0031] In addition, the present invention allows the inductance of the inductor to be varied according to the load, thereby varying the inductance of the inductor according to the changed inductance of the load when the load changes. Therefore, the inductance of the semiconductor circuit breaker can be maintained at a constant value regardless of the change in the load.

[0032] Figure 1 is a block diagram showing the configuration of a typical semiconductor circuit breaker.

[0033] FIG. 2 is a block diagram illustrating the structure of a semiconductor circuit breaker according to an embodiment of the present invention.

[0034] FIG. 3 is a conceptual diagram for explaining the concept of a load and an inductor forming one inductor in a semiconductor circuit breaker according to an embodiment of the present invention.

[0035] FIG. 4 is a block diagram illustrating a configuration of a power supply system in which semiconductor switch units connected to a plurality of power supply units commonly use one inductor according to an inductor separation structure of a semiconductor circuit breaker according to an embodiment of the present invention.

[0036] Fig. 5 is a block diagram illustrating the configuration of a semiconductor circuit breaker including a semiconductor switch section capable of controlling bidirectional current flow.

[0037] Fig. 6 is an exemplary diagram showing an example of current being supplied from system A to system B in the semiconductor circuit breaker of Fig. 5.

[0038] Fig. 7 is an exemplary diagram showing an example of current being supplied from system B to system A in the semiconductor circuit breaker of Fig. 5.

[0039] It should be noted that the technical terms used herein are merely used to describe specific embodiments and are not intended to limit the present invention. Furthermore, the singular forms used herein include plural forms unless the context clearly dictates otherwise. In this specification, terms such as "consist of" or "comprises" should not be construed to necessarily include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0040] In addition, when describing the technology disclosed in this specification, if it is determined that a detailed description of a related known technology may obscure the gist of the technology disclosed in this specification, the detailed description is omitted.

[0041] Hereinafter, embodiments disclosed in this specification will be described in detail with reference to the attached drawings.

[0042] FIG. 2 is a block diagram illustrating the structure of a semiconductor circuit breaker (200) according to an embodiment of the present invention.

[0043] First, (a) of FIG. 2 is a block diagram showing the configuration of a semiconductor circuit breaker (200) according to an embodiment of the present invention, which is arranged in a power supply unit (160) that supplies current to a load (150) and a circuit that supplies current between the power supply unit (160) and the load (150).

[0044] As shown in (a) of Fig. 2, the power supply unit (160) and the load (150) can form a closed circuit. That is, a closed circuit can be formed in which current is supplied to the load (150) through a circuit (hereinafter, input circuit (210)) through which current is input from the power supply unit (160) to the load (150), and the current output from the load (150) is supplied back to the power supply unit (160) through a circuit (hereinafter, return circuit (220)) through which current is output from the load (150) and returned to the power supply unit (160). In this way, the circuit must be in a closed state so that the current from the power supply unit (160) can be supplied to the load (150).

[0045] Meanwhile, a semiconductor circuit breaker (200) according to an embodiment of the present invention may be configured to include, as shown in (a) of FIG. 2, a semiconductor switch unit (140) disposed on the input path (210) through which current is supplied from a power supply unit (160) to a load (150), a control unit (100) that controls the semiconductor switch unit (140), and at least one inductor (130) disposed on the return path (220) through which current flows from the load (150) to the power supply unit (160).

[0046] Here, the semiconductor switch unit (140) may be formed by including at least one semiconductor switch (120) formed using a power semiconductor, and a gate driver (110) that applies a gate voltage to a gate terminal of each semiconductor switch (120). In addition, the semiconductor switch (120) may include a source (or collector) terminal, a drain (or emitter) terminal, and a gate (or base) terminal of the power semiconductor. Here, the semiconductor switch (120) may be configured as an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

[0047] In addition, the semiconductor switch unit (140) may include a rectifier element that is connected in parallel with each semiconductor switch (120) and is arranged in a direction opposite to the current flow by the semiconductor switch (120). Here, the rectifier element may include at least one of a diode, a rectifier (e.g., a bridge rectifier), or a thyristor.

[0048] Meanwhile, the semiconductor switch (120) can be electrically connected between the source terminal and the drain terminal when a gate voltage higher than a preset threshold voltage is applied from the gate driver (110) according to the characteristics of the power semiconductor. Accordingly, when a gate voltage higher than the threshold voltage is applied to the gate terminal, electricity can be conducted through the semiconductor switch (120).

[0049] Meanwhile, as shown in (a) of FIG. 2, when the semiconductor switch unit (140) is composed of one semiconductor switch (120), the source terminal of the semiconductor switch (120) can be connected to the power supply unit (160). On the other hand, the drain terminal of the semiconductor switch (120) can be connected to the load (150). Therefore, when a gate voltage higher than the threshold voltage is applied to the gate terminal, the source terminal and the drain terminal are electrically connected, and thus an input path (210) connecting the power supply unit (160) and the load (150) through the semiconductor switch (120) can be formed. Then, the current of the power supply unit (160) can be supplied to the load (150) along the formed input path (210).

[0050] Meanwhile, the control unit (100) can control the gate driver (110) to control the gate voltage applied to the gate terminal by the gate driver (110). For example, the control unit (100) can control the gate driver (110) so that a gate voltage higher than a preset threshold voltage is applied when normal operation is performed. Accordingly, the source terminal and drain terminal of the semiconductor switch (120) are connected, and power from the power supply unit (160) can be supplied to the load (150) through the input circuit (210).

[0051] In this way, in a state where the source terminal and the drain terminal are connected, the control unit (100) can detect the current flowing in the input circuit (210) or the return circuit (220). And, based on the detection result, it can be determined whether an abnormal current has occurred due to a short circuit or leakage current. And, if it is determined that an abnormal current has occurred, the gate driver (110) can be controlled so that a gate voltage lower than the threshold voltage is applied, or so that the gate voltage is not applied.

[0052] Then, the electrical connection between the source terminal and the drain terminal is cut off, and the input circuit (210) is opened, so that the current supply from the power supply unit (160) to the load (150) can be stopped. Therefore, the abnormal current can be prevented from being supplied to the load (150).

[0053] Meanwhile, in the semiconductor circuit breaker (200) according to an embodiment of the present invention, as shown in (a) of the above FIG. 2, the inductor (130) may be separated from the semiconductor switch unit (140) and placed on a different circuit. That is, the semiconductor switch unit (140) including the semiconductor switch may be placed on an input circuit (210) to which current is supplied from the power supply unit (160), while the inductor (130) may be placed on a return circuit (220) to which current is returned from the load (150). Accordingly, as shown in (a) of the FIG. 2, the inductor (130) of the semiconductor circuit breaker (200) according to an embodiment of the present invention may be placed on a different circuit from the circuit on which the semiconductor switch unit (140) is placed. For example, the inductor (130) may be placed between the output terminal of the load (150) and the power supply unit (160).

[0054] Meanwhile, when an inductor is equipped in a semiconductor circuit breaker, when the semiconductor switch unit is turned on, energy is charged and a magnetic field is generated. Conversely, when the semiconductor switch unit is turned off, the magnetic field that is dissipated according to Lenz's law induces a current in the opposite direction. Accordingly, a negative potential is generated in the inductor that had a positive potential, generating a current in the opposite direction, and a voltage much larger than the voltage applied to the inductor, i.e., a counter electromotive force, can be formed at both ends of the semiconductor switch unit. In addition, the counter electromotive force is a voltage spark generated by the inductor, and can cause damage to the system due to the high voltage.

[0055] Therefore, as in the conventional semiconductor circuit breaker described in the above-mentioned Fig. 1, when an inductor is placed in a single circuit with the semiconductor switch section, a separate circuit, such as a flyback circuit or a freewheeling circuit, must be provided at both ends of the semiconductor switch section to eliminate the counter electromotive force. In addition, this separate circuit is an additional component added in addition to the semiconductor switch section, and causes the size of the semiconductor circuit breaker to increase.

[0056] However, as described above, the counter electromotive force is generated to consume the energy stored in the inductor when the current supply is suddenly cut off by the semiconductor switch unit, and can be eliminated by creating a path through which the current of the inductor can flow at both ends of the inductor.

[0057] Therefore, when a circuit including a flyback diode, a freewheeling diode, or a catch diode arranged in the opposite direction to the current flow in the inductor when the semiconductor switch unit (140) is turned on is arranged at both ends of the inductor, the counter electromotive force can be eliminated.

[0058] However, as shown in (a) of FIG. 2, the semiconductor circuit breaker (200) according to the embodiment of the present invention arranges the inductor (130) in a separate circuit from the circuit in which the semiconductor switch unit (140) is arranged. Therefore, a separate circuit (260) for eliminating counter electromotive force, for example, a flyback circuit or a freewheeling circuit, can be arranged in the circuit in which the inductor (130) is arranged, thereby separating it from the semiconductor switch unit (140). In this case, the diodes arranged in the circuit (260) for eliminating counter electromotive force may have polarities arranged in the opposite direction to the current flow through the return circuit (220), that is, the current flow from the load (150) to the power source (160). That is, in the case as shown in (a) of FIG. 2, the diodes of the counter electromotive force eliminating circuit may be arranged in the same direction as the direction in which current flows through the input circuit (210).

[0059] In this way, in the present invention, the inductor (130) and the counter electromotive force elimination circuit (260) of the semiconductor circuit breaker (200) can be placed in a different circuit from the circuit where the semiconductor switch unit (140) is placed. Therefore, by arranging the inductor and the counter electromotive force elimination circuit separately from the semiconductor switch unit according to the shape or space where the circuits connected to the load (150) are placed, there is an effect of more efficient use of space. That is, when the input circuit (210) is very narrow, only the semiconductor switch unit (140) of the semiconductor circuit breaker (200) according to the embodiment of the present invention is placed in the input circuit (210), and the inductor (130) and the counter electromotive force elimination circuit (260) are placed in the return circuit (220), so that the semiconductor circuit breaker can be placed in a space or environment where it is difficult to place an existing semiconductor circuit breaker.

[0060] Moreover, since the inductor (130) is arranged in a separate circuit from the semiconductor switch as described above, the present invention can secure sufficient space for arranging the inductor (130). Accordingly, an inductor with a higher inductance can be used, and there is an advantage in that sufficient space can be secured for arranging the flyback diode, freewheeling diode, or resistor of the counter electromotive force elimination circuit (260).

[0061] Meanwhile, a link capacitor (250) may be further provided between the input circuit (210) and the return circuit (220) according to an embodiment of the present invention. For example, the link capacitor (250) may be connected in parallel to the power supply unit (160) as shown in (a) of FIG. 2.

[0062] In this case, the control unit (100) can repeatedly turn on / off the semiconductor switch unit (140) until a preset voltage is reached, in a state where the semiconductor switch unit (140) is off, that is, in a state where the gate driver (110) applies a gate voltage lower than the threshold voltage or does not apply a gate voltage. Here, the on state of the semiconductor switch unit (140) may mean a state where the gate driver (110) applies a gate voltage higher than the threshold voltage.

[0063] In this case, when the semiconductor switch unit (140) is turned on, the link capacitor (250) can be charged first. And when the semiconductor switch unit (140) is turned off, the current charged in the link capacitor (250) can flow into the load (150). Therefore, as a result, the time for the capacitor inside the load (150) to be charged is lengthened, and the voltage increase speed is reduced, thereby preventing the generation of inrush current. In addition, the inductor (130) arranged in the return path (220) plays the role of a resistor to prevent the generation of the inrush current, thereby preventing the generation of the inrush current.

[0064] Meanwhile, in the above description, the circuit through which current is input to the load (150) is called an input circuit (210), and the circuit through which current is returned from the load (150) is called a return circuit (220). However, the input circuit (210) may be a P (Positive) phase circuit, i.e., a live line or hot line, and the return circuit (220) may be an N phase circuit, i.e., a neutral line. Fig. 2 (b) illustrates an example of such a case.

[0065] Referring to (b) of FIG. 2, the semiconductor switch unit (140) may be placed on the P-phase circuit (211). And the inductor (130) may be placed on the N-phase circuit (221). Therefore, as shown in (b) of FIG. 2, the semiconductor switch unit (140) and the inductor (130) according to the embodiment of the present invention may be placed on different circuits. Alternatively, the semiconductor switch unit (140) and the inductor (130) may be placed on different circuits that are connected in parallel to the load (150).

[0066] Meanwhile, as examined in (a) and (b) of the above-described FIG. 2, the inductor (130) of the semiconductor circuit breaker (200) according to the embodiment of the present invention may be placed on another electrical path connected to the load (150) separately from the semiconductor switch unit (140). For example, the inductor (130) may be placed on an electrical path through which a current returning from the load (150) is output, and in this case, in a closed circuit in which the semiconductor circuit breaker (200) according to the embodiment of the present invention is placed, the load (150) and the inductor (130) may perform the same role as a single inductor.

[0067] FIG. 3 is a conceptual diagram for explaining the concept of a load (150) and an inductor (130) forming a single inductor (300) in a semiconductor circuit breaker according to an embodiment of the present invention. For example, the load (150) may be an inductive load.

[0068] Referring to FIG. 3, first, as shown in (a) of FIG. 3, when an inductor (130) is placed in an N-phase circuit (221) from which a return current is output from a load (150), the load (150) and the inductor (130) may be placed in series with each other. That is, the inductor (130) according to an embodiment of the present invention may have a configuration in which the load (150) is connected after the semiconductor switch unit (140), and the inductor (130) is connected after the load (150) (in series), as shown in (a) of FIG.

[0069] Meanwhile, if the load (150) is an inductive load, the load (150) may have its own inductance. Therefore, when the load (150) and the inductor (130) are connected in series, the total inductance of the power supply circuit (closed circuit) that supplies power to the load (150) may be the sum of the inductance of the load (150) and the inductance of the inductor (130). Therefore, as shown in (a) of Fig. 3, when the load (150) and the inductor (130) are connected in series, they may operate as a single inductor (hereinafter, a composite inductor (300)). In addition, the rate of increase of the current supplied through the semiconductor switch unit (140) may be limited depending on the inductance provided by the composite inductor (300).

[0070] Meanwhile, as shown in (a) of FIG. 3, when a load (150) and an inductor (130) are connected to each other to form a composite inductor (300), the inductance applied to the semiconductor circuit breaker (200) according to the embodiment of the present invention may be the inductance of the load (150) added to the inductance of the inductor (130). Therefore, when the inductance of the load (150) is sufficient, there is an advantage in that sufficient inductance can be secured even when the inductance of the inductor (130) is small.

[0071] Here, according to an embodiment of the present invention, the inductor arranged in a different circuit from the semiconductor switch unit (140) may be a variable inductor (130) capable of changing inductance. In addition, if the load (150) is an inductive load, the load (150) also has inductance, and therefore, as shown in (b) of FIG. 3, if the variable inductor (130) is connected to the output terminal of the load (150), the load (150) and the variable inductor (130) may operate as a single inductor (e.g., a composite inductor (300)).

[0072] Meanwhile, the inductance of the variable inductor (130) can be changed according to the control of the control unit (100). Therefore, when the inductance of the load (150) increases or decreases, the control unit (100) can decrease or increase the inductance of the variable inductor (600) by reflecting the inductance of the load (150). Therefore, the total inductance of the power supply circuit that supplies power to the load (150) can be kept constant. That is, even when the inductance of the load (150) changes, the semiconductor circuit breaker according to the embodiment of the present invention has the effect of always maintaining the optimal inductance required by the semiconductor switch unit (140) by adjusting the inductance of the variable inductor (130). In addition, since a constant inductance can be maintained even when the load fluctuates (e.g., inductance changes), there is an advantage in that the stability of the power supply circuit can be further increased.

[0073] Meanwhile, the above description describes an example in which power is supplied from one power supply unit to a load, but it goes without saying that the load may be formed so as to receive power from multiple different power supplies.

[0074] For example, the load may be connected to a commercial power source, or may be connected to at least one distributed power generation facility, such as a solar power plant or a geothermal power plant. Alternatively, the load may be connected to one or more uninterruptible power supply systems (UPS), energy storage systems (ESS), and batteries. Each of these energy supply devices may function as a power supply unit capable of supplying operating power to the load. Each power supply unit may be electrically connected to the load through a respective semiconductor switch unit equipped with a semiconductor switch.

[0075] Here, the power supply unit may have a form in which multiple energy storage devices are connected in series (e.g., batteries are connected in series). In the case of a power supply unit in which multiple energy storage devices are connected in series, a semiconductor switch may be placed between the multiple energy storage devices connected in series.

[0076] For example, when two energy storage devices are connected in series to form a power supply, the semiconductor switch may be arranged between the two energy storage devices, so that the two energy storage devices can be connected via the semiconductor switch. In this way, when a plurality of energy storage devices are divided into two parts by the semiconductor switch arranged in the middle, if a short circuit occurs between the energy storage devices included in one part, the energy storage devices of the other parts connected after the semiconductor switch are cut off by the semiconductor switch, so that the energy storage devices of the other parts where the short circuit does not occur can be protected from the short circuit current.

[0077] Meanwhile, a semiconductor circuit breaker (200) according to an embodiment of the present invention has a separate structure in which a semiconductor switch unit is disposed in a power supply unit that supplies power, and an inductor is disposed in a load. Accordingly, when a plurality of power supply units are connected to a load, the present invention may provide a semiconductor switch unit including at least one semiconductor switch in each power supply unit, and an inductor may be disposed in the load. In this case, the inductor disposed on the load side may provide an inductance that is commonly applied to the semiconductor switch units disposed in each of the plurality of power supply units. In other words, it may be a common inductor commonly used by the semiconductor switch units disposed in each of the plurality of power supply units.

[0078] FIG. 4 is a block diagram illustrating a configuration of a power supply system in which semiconductor switch units connected to a plurality of power supply units use one inductor in common according to the inductor separation structure of the semiconductor circuit breaker according to the embodiment of the present invention described above.

[0079] Referring to FIG. 4, a power supply system according to an embodiment of the present invention may be provided with a plurality of different power supply units (401, 402, 403, ...) capable of supplying power to a load (430). In addition, a control unit (470) may be provided to control gate drivers of semiconductor switch units (410) provided in each of the plurality of power supply units so that electrical connection is established between the plurality of power supply units and the load (430).

[0080] Here, the plurality of power supply units may be connected in parallel to each other via a bus. The load (430) may be connected to at least one of the plurality of power supply units connected in parallel via the bus, and may receive power required for driving through at least one of the connected power supply units.

[0081] In addition, each of the plurality of power supply units may be provided with a semiconductor switch unit (410) including at least one semiconductor switch using a power semiconductor so as to be able to quickly cut off the current supply when an abnormal current occurs. That is, each of the plurality of power supply units may be configured to include a power supply that supplies current and a semiconductor switch unit that connects the power supply and a bus. For example, the first power supply unit (401) may include a power supply corresponding to the power supply unit (160) in (a) of FIG. 2 and a semiconductor switch unit (410) corresponding to the semiconductor switch unit (140).

[0082] Meanwhile, according to the above-described description, in a semiconductor circuit breaker according to an embodiment of the present invention, a semiconductor switch unit and an inductor may be separately arranged on an input circuit through which power is supplied to a load, for example, a P-phase circuit, and a return circuit through which current output from the load is returned, for example, an N-phase circuit. Accordingly, semiconductor switch units (410) may be provided on each of the plurality of power supply units, and an inductor (450) may be arranged on the load (430) side.

[0083] As shown in Fig. 4, the present invention separates the inductor from the power supply and places it on the load (430), so the inductor (450) can be placed away from the power supply.

[0084] With this configuration, when the load (430) is connected to the first power supply unit (401) and is supplied with power, the inductor (450) can provide inductance applied to the first semiconductor switch unit provided in the first power supply unit (401). In addition, when the load (430) is connected to the second power supply unit (402) and is supplied with power, the inductor (450) can provide inductance applied to the second semiconductor switch unit provided in the second power supply unit (402). In addition, when the load (430) is connected to the third power supply unit (403) and is supplied with power, the inductor (450) can provide inductance applied to the third semiconductor switch unit provided in the third power supply unit (403). That is, the inductor (450) may be an inductor commonly used by each semiconductor switch unit provided in the first power supply unit (401) to the third power supply unit (403), and accordingly, the inductor (450) may provide an inductance commonly applied to each semiconductor switch unit (410) disposed in each of the plurality of power supply units.

[0085] Accordingly, according to the configuration of a semiconductor circuit breaker according to an embodiment of the present invention, as shown in FIG. 4, a power supply system can be configured in which semiconductor switches connected to a plurality of power sources share a single inductor. Therefore, by saving space for arranging inductors in each of the plurality of semiconductor switch units, a more compact power supply unit switch can be configured.

[0086] Moreover, as described above, in the present invention, the inductor (450) is disposed on the load (430) side and is disposed in a separate circuit from the semiconductor switch unit (410). Accordingly, the circuit (460) for eliminating counter electromotive force can also be disposed between both ends of the inductor (450) disposed on the load (430) side. Therefore, the counter electromotive force eliminating circuit (460) can also be commonly applied to the semiconductor switch units disposed in each of the plurality of power supply units. As a result, the space for the counter electromotive force eliminating circuit (460) in the semiconductor switch unit of each power supply unit can be saved, so that the size of the switch unit including the semiconductor switch unit in each power supply unit can be reduced, and its structure can also be simplified.

[0087] Meanwhile, in the power supply system described above, if there are multiple power supply units connected to the load (430), the control unit (470) can control the amount of current supplied from each of the multiple power supply units to the load (430) by controlling the on and off of the semiconductor switch unit of each of the multiple power supply units connected to the load (430).

[0088] That is, when the semiconductor switch unit is turned on, current can be supplied from the connected power supply unit, and when the semiconductor switch unit is turned off, current supply from the connected power supply unit can be cut off. The control unit (470) can control the amount of current supplied from a specific power supply unit to the load (430) during a time corresponding to one duty cycle by adjusting the on / off switching duty rate of the semiconductor switch unit.

[0089] Meanwhile, if there are multiple power supply units connected to the load (430) as described above, the control unit (470) can control the amount of current supplied to the load (430) from each of the multiple power supply units connected to the load (430) according to the requirements required by the system.

[0090] For example, assuming that the current supplied from the distributed power generation facility and the current supplied from the commercial power source are the same, it can be assumed that the system requirement is to supply the current supplied from the distributed power generation facility and the current supplied from the commercial power source to the load (430) at a ratio of 8:2 (the time corresponding to one duty cycle is the same).

[0091] In this case, the control unit (470) can switch on / off a semiconductor switch placed on a power line supplied with power from the distributed power generation facility at a duty ratio of 80%, and switch on / off a semiconductor switch placed on a power line supplied with power from the commercial power source at a duty ratio of 20%. Accordingly, during one duty cycle, 80% of the current supplied to the load (430) can be supplied from the distributed power generation facility, and the remaining 20% ​​can be supplied from the commercial power source.

[0092] Meanwhile, the above description describes the configuration of a semiconductor switch unit that controls a one-way current supply from a power supply unit to a load, but the present invention can also be applied to a case where a semiconductor switch unit that controls a two-way current supply is included.

[0093] Fig. 5 is a block diagram illustrating the configuration of a semiconductor circuit breaker including a semiconductor switch unit capable of controlling bidirectional current flow in this manner.

[0094] Referring to FIG. 5, a semiconductor circuit breaker according to an embodiment of the present invention may include a semiconductor switch unit (310) including a first semiconductor switch (321) and a second semiconductor switch (322) that can be turned on / off and are connected in series with each other between an A system (360) and a B system (370).

[0095] Here, the A system (360) and the B system (370) may be different power systems. For example, the A system (360) and the B system (370) may be different microgrids. In this case, a bidirectional current flow may be formed not only from the A system (360) to the B system (370), but also from the B system (370) to the A system (360).

[0096] Alternatively, system A (360) may be a power system and system B (370) may be a load. In this case, a current flow may be formed from system A (360) to system B (370). Conversely, system A (360) may be a load and system B (370) may be a power system. In this case, a current flow may be formed from system B (370) to system A (360).

[0097] In order to control this bidirectional current flow, the first semiconductor switch (321) and the second semiconductor switch (322) can be formed so that the circuit can be interrupted not only when current flows from the A system (360) to the B system (370), but also when current flows from the B system (370) to the A system (360).

[0098] For this purpose, the first semiconductor switch (321) and the second semiconductor switch (322) may be semiconductor switches formed of N-channel MOSFET elements in which the source and drain are arranged in opposite directions. However, it goes without saying that the present invention is not limited thereto, and the first and second semiconductor switches (321, 322) may be any element that can be turned on / off by a gate voltage controlled by the control unit (300), such as an IGBT, GTO, or IGCT, instead of the MOSFET element.

[0099] And the first and second gate drivers (311, 312) can apply gate voltages to the gate terminals of the first and second semiconductor switches (321, 322), respectively, under the control of the control unit (300). In this case, when a gate voltage exceeding a threshold voltage is applied to at least one of the first and second semiconductor switches (321, 322), the resistance size of the output terminal of at least one of the first and second semiconductor switches (321, 322) can become smaller than that of the input terminal. Therefore, the input terminal and the output terminal of at least one of the first and second semiconductor switches (321, 322) can be electrically connected by being conducted.

[0100] Meanwhile, the first semiconductor switch (321) and the second semiconductor switch (322) may further include first and second diodes (331, 332) arranged in the opposite direction to the current flow to prevent damage due to reverse voltage when the circuit is cut off due to an abnormal current. In this case, the anode and cathode of the first and second diodes (331, 332) may be connected to the source terminal and drain terminal of the first and second semiconductor switches (321, 322), respectively.

[0101] Accordingly, the first diode (331) may be connected in parallel with the first semiconductor switch (321) and arranged in the reverse direction to the current flowing from the A system to the B system. And the second diode (332) may be connected in parallel with the second semiconductor switch (322) and arranged in the reverse direction to the current flowing from the B system to the A system.

[0102] In this way, a semiconductor circuit breaker according to an embodiment of the present invention can be formed to block fault currents flowing in both directions by including a first semiconductor switch (321) and a second semiconductor switch (322) configured in a complementary symmetrical form.

[0103] Meanwhile, as shown in FIG. 5, the semiconductor switch unit (310) and the inductor (500) may be placed on different circuits connecting the A system (360) and the B system (370). For example, if the semiconductor switch unit (310) is placed on an input circuit (510) through which current is supplied between the A system (360) and the B system (370), the inductor (500) may be placed on another circuit, that is, a return circuit (520) through which current supplied between the A system (360) and the B system (370) is returned to the B system (370) or the current output from the A system (360). That is, the inductor (500) may be placed on a separate circuit from the semiconductor switch unit (310) and separated from the semiconductor switch unit (310).

[0104] Meanwhile, in the semiconductor circuit breaker according to an embodiment of the present invention, the inductor may be a variable inductor. In this case, the control unit (300) can control the inductance of the variable inductor to maintain the inductance applied to the power supply circuit shown in FIG. 5 constant.

[0105] First, FIG. 6 is an exemplary diagram showing an example of current being supplied from system A (360) to system B (370) in the semiconductor circuit breaker of FIG. 5.

[0106] Referring to FIG. 6, in the semiconductor circuit breaker according to the embodiment of the present invention illustrated in FIG. 5, the control unit (300) can control the gate drivers (311, 312) so that a gate voltage higher than the threshold voltage is applied to the gate terminals of the first and second semiconductor switches (321, 322), respectively. Then, the A system (360) and the B system (370) are electrically connected through the semiconductor switch unit (310), and the current of the A system (360) can be supplied to the B system (370).

[0107] In this way, when current is supplied from system A (360) to system B (370), system A (360) may correspond to a power supply, and system B (370) may be a load. Then, the variable inductor (600) may be placed on a return path through which the current supplied from system A (360) is output from system B (370) and returned to system A (360). In this case, the sum of the inductance of the variable inductor (600) and the inductance of system B (370) may form an inductance applied to the power supply circuit.

[0108] Accordingly, the control unit (300) can calculate the first inductance (β) for maintaining the inductance of the power supply circuit constant based on the inductance of the B system (370) corresponding to the load. Then, by changing the inductance of the variable inductor (600) according to the calculated first inductance (β), the inductance of the power supply circuit can be maintained constant.

[0109] FIG. 7 is an exemplary diagram showing an example of current being supplied from the B system (370) to the A system (360) in the semiconductor circuit breaker of FIG. 5, contrary to the above FIG. 6.

[0110] Referring to FIG. 7, in the semiconductor circuit breaker according to the embodiment of the present invention illustrated in FIG. 5, the control unit (300) can control the gate drivers (311, 312) so that a gate voltage higher than the threshold voltage is applied to the gate terminals of the first and second semiconductor switches (321, 322), respectively. Then, the A system (360) and the B system (370) are electrically connected through the semiconductor switch unit (310), and the current of the B system (370) can be supplied to the A system (360).

[0111] In this way, when current is supplied from the B system (370) to the A system (360), the B system (370) may correspond to a power supply, and the A system (360) may be a load. Then, the variable inductor (600) may be placed on a return path through which the current supplied from the B system (370) is output from the A system (360) and returned to the B system (370). In this case, the sum of the inductance of the variable inductor (600) and the inductance of the A system (360) may form an inductance applied to the power supply circuit.

[0112] Therefore, the control unit (300) can calculate the second inductance (α) for maintaining the inductance of the power supply circuit constant based on the inductance of the A system (360) corresponding to the load. In this case, if the inductance of the B system (370) is greater than the inductance of the A system (360), the control unit (300) can calculate the second inductance (α) greater than the first inductance (β). In addition, the inductance of the variable inductor (600) can be changed according to the calculated second inductance (α). Therefore, even when supplying current between systems having different inductances, the present invention can maintain the inductance applied to the power supply circuit constant.

[0113] While the above-described description of the present invention has described specific embodiments, various modifications may be made without departing from the scope of the present invention. In particular, the embodiments of the present invention have been described with the example of a semiconductor switch unit including a single semiconductor switch in a case where current is supplied unidirectionally. However, even in a case where current is supplied unidirectionally, the semiconductor switch unit may of course include a plurality of semiconductor switches.

[0114] Meanwhile, a semiconductor circuit breaker according to an embodiment of the present invention may further include a blocking switch that can physically connect or disconnect a semiconductor switch unit from a power supply circuit that supplies power to a load. In this case, the blocking switch may be controlled by a control unit so that the semiconductor switch is turned off and operated simultaneously when an abnormal current such as a short circuit or leakage current occurs. In this case, since the semiconductor switch operates at a higher speed than the blocking switch, the semiconductor switch can first open the input circuit before the blocking switch blocks the semiconductor switch unit, thereby blocking an abnormal current from flowing into the load, and the semiconductor switch unit can be physically blocked from the input circuit while the input circuit is open.

[0115] The present invention described above can be implemented as computer-readable code on a medium in which a program is recorded. Computer-readable media include all types of recording devices that store data that can be read by a computer system. Examples of computer-readable media include hard disk drives (HDDs), solid-state disks (SSDs), silicon disk drives (SDDs), ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, etc., and also include media implemented in the form of carrier waves (e.g., transmission via the Internet). In addition, the computer may include a control unit of a terminal. Therefore, the above detailed description should not be construed as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are intended to be included in the scope of the present invention.

Claims

1. In a solid state circuit breaker placed between the power source and the load, A semiconductor switch unit disposed on an input circuit through which current is supplied from the power source to the load, and including at least one semiconductor switch for opening or closing the input circuit; A control unit that controls the opening or closing of the input circuit by controlling the gate driver of at least one semiconductor switch; and A semiconductor circuit breaker characterized in that it includes at least one inductor arranged in a return path through which current output from the load is returned to the power source, as a separate path from the input path in which the semiconductor switch unit is arranged.

2. In paragraph 1, The above input circuit is a live P (Positive) phase circuit, A semiconductor circuit breaker characterized in that the above return path is a neutral N (Neutral) phase path.

3. In the first paragraph, at least one inductor, A semiconductor circuit breaker disposed between the output terminal of the load and the power source, characterized in that it is connected in series with the load at the rear end of the load.

4. In paragraph 1, At least one semiconductor switch, It includes a rectifier element arranged in the opposite direction to the direction in which the semiconductor switch is arranged, The above rectifier element, A semiconductor circuit breaker comprising at least one of a diode, a rectifier, or a thyristor.

5. In the first paragraph, the semiconductor switch, A semiconductor circuit breaker characterized by being composed of an insulated gate bipolar transistor (IGBT) or a metal oxide semiconductor field effect transistor (MOSFET).

6. In paragraph 1, A semiconductor circuit breaker characterized in that it further comprises a counter electromotive force elimination circuit for eliminating counter electromotive force generated when current supply is interrupted due to the semiconductor switch being turned off, in a circuit different from the circuit where the semiconductor switch part is arranged.

7. In the 6th paragraph, the counter electromotive force elimination circuit, Connected to both ends of the inductor placed on a different circuit from the circuit where the semiconductor switch part is placed, A semiconductor circuit breaker characterized by including at least one diode having a polarity arranged in a direction opposite to the direction in which current flows through the circuit in which the inductor is arranged.

8. In paragraph 1, A semiconductor circuit breaker characterized in that a link capacitor connected in parallel to the power source is further provided between the input circuit and the return circuit.

9. In paragraph 1, The above semiconductor switch part, It comprises first and second semiconductor switches arranged between the first power system and the second power system, connected in series with each other and arranged in opposite directions, A semiconductor circuit breaker characterized in that one of the first power system and the second power system is a power source that supplies current to the other, and the other operates as a load that receives current from the one of the first power systems.

10. In paragraph 1, The above inductor, It is a variable inductor whose inductance can be changed. The above control unit, A semiconductor circuit breaker characterized in that, when the load is changed, the total inductance, which is the sum of the inductance of the changed load and the inductance of the variable inductor, is changed so as to form a preset inductance.

11. In paragraph 10, the load is A semiconductor circuit breaker characterized by an inductive load.

12. In a power supply system including multiple power sources that supply power to a load, A bus that connects the plurality of power sources in parallel and connects the plurality of power sources connected in parallel to the load; A plurality of semiconductor switch sections, each of which is disposed between a power source and the bus and includes at least one semiconductor switch for opening or closing a path through which current is supplied from each power source to the bus; A control unit that controls the gate drivers of each semiconductor switch included in the plurality of semiconductor switch units to control the opening or closing of each electric path through which current is supplied to the bus from each power source; and A power supply system characterized by including a common inductor arranged at the output terminal of the above load and providing inductance commonly applied to each of the plurality of semiconductor switch sections.

13. In paragraph 12, A power supply system further comprising a counter electromotive force elimination circuit including at least one diode connected to both ends of the common inductor and having a polarity arranged in the opposite direction to the direction in which current flows through the circuit in which the common inductor is arranged.

14. In paragraph 12, Among the above multiple power sources, the first power source is: Contains two or more energy storage devices connected in series, A semiconductor switch unit disposed between the first power source and the bus, A power supply system characterized in that it is placed between two or more energy storage devices connected in series.

15. In paragraph 12, the control unit, A power supply system characterized in that the duty rate, which is the ratio of the time the semiconductor switch unit is turned on and the time the semiconductor switch unit is turned off during a preset period of time, is controlled differently for each of the plurality of power sources so that the ratio of the amount of current supplied to the load by each of the plurality of power sources is different.

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