Control device, semiconductor shutoff system, semiconductor switch control method, control program, and recording medium

Abstract

To provide a control device, etc. which can reduce possibility of occurrence of erroneous determination in determination processing of excess current.SOLUTION: A control device (3) comprises: a calculation unit (31) which calculates, on the basis of predetermined operation characteristic information at least including characteristic information regarding operation characteristics of a semiconductor switch (2), and a current value obtained from a detection result of a current sensor (4), energizable time as time for allowing energization when current having the current value is continuously energized to the semiconductor switch (2); and an opening / closing control unit (32) which performs opening / closing control of the semiconductor switch (2) on the basis of the energizable time calculated by the calculation unit (31).SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a control device for a semiconductor switch that performs a blocking operation, etc.

Background Art

[0002] In recent years, a semiconductor interruption system equipped with a semiconductor switch has been used in a power system that supplies power from a power source to a load. When an overcurrent flows through the semiconductor switch, such a semiconductor interruption system operates the semiconductor switch to quickly interrupt it when a short-circuit accident occurs on the load side.

[0003] In a conventional control device for a semiconductor switch, a user sets a steady-state overcurrent threshold determined based on the rated current of the load and a short-time overcurrent threshold larger than the steady-state overcurrent threshold as thresholds for causing the semiconductor switch to perform a blocking operation based on the power source and load of the power system. Further, this conventional control device for a semiconductor switch discloses acquiring the current flowing through the semiconductor switch and changing the threshold from the steady-state overcurrent threshold to the short-time overcurrent threshold within a range of current in which the semiconductor switch does not undergo thermal breakdown due to Joule heat (see, for example, Patent Document 1 below).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, with conventional semiconductor switch control devices as described above, users had to predict the peak value of the current flowing through the semiconductor switch and pre-set the short-time overcurrent threshold based on the electrical characteristics of the power supply, such as its supply capacity, and the electrical characteristics of the load, such as its power consumption. As a result, conventional semiconductor switch control devices sometimes failed to properly set the short-time overcurrent threshold, leading to problems such as misjudgments in the overcurrent detection process.

[0006] This disclosure was made in view of the above-mentioned problems, and aims to provide a control device, etc., that can reduce the possibility of misjudgment occurring in the overcurrent determination process. [Means for solving the problem]

[0007] To solve the above problems, a control device relating to one aspect of the present disclosure is a semiconductor interruption system comprising: a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts current from the power source to the load; and a current sensor that detects current flowing from the power source to the semiconductor switch, wherein the control device for controlling the semiconductor switch comprises: a calculation unit that calculates an energizable time, which is the time during which current having the said current value can be continuously supplied to the semiconductor switch, based on predetermined operating characteristic information, which includes at least characteristic information relating to the operating characteristics of the semiconductor switch, and a current value obtained from the detection result of the current sensor; and an opening / closing control unit that controls the opening and closing of the semiconductor switch based on the energizable time calculated by the calculation unit.

[0008] Furthermore, a semiconductor interruption system relating to one aspect of this disclosure includes a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load; a current sensor that detects the current flowing from the power source to the semiconductor switch; and the control device.

[0009] Furthermore, a control method for a semiconductor switch relating to one aspect of the present disclosure is a control method for controlling a semiconductor switch in a semiconductor system comprising: a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts current from the power source to the load; and a current sensor that detects current flowing from the power source to the semiconductor switch, the control method comprising: a current detection step in which the current sensor detects current flowing through the semiconductor switch; a calculation step in which, based on characteristic information relating to the operating characteristics of the semiconductor switch and a current value obtained from the detection result of the current detection step, the semiconductor switch can be energized for a period of time when a current having the said current value is continuously energized through the semiconductor switch; and an opening / closing control step in which the semiconductor switch is opened and closed based on the energized time calculated in the calculation step.

[0010] Furthermore, a control device relating to one aspect of this disclosure may be implemented by a computer, in which case a control program for a control device that implements the control device by operating the computer as each part (software element) of the control device, and a computer-readable recording medium on which the program is recorded, also fall within the scope of this disclosure. [Effects of the Invention]

[0011] According to one aspect of this disclosure, it is possible to provide a control device, etc., that can reduce the possibility of misjudgment occurring in the overcurrent determination process. [Brief explanation of the drawing]

[0012] [Figure 1] This is a schematic diagram showing a control device and a semiconductor interruption system equipped therewith according to one embodiment of the present disclosure. [Figure 2] Figure 1 is a perspective view showing the semiconductor switch and the cooler used to cool it. [Figure 3] This graph shows an example of a specific waveform of the collector-emitter saturation voltage characteristic of the semiconductor switch described above. [Figure 4]This graph shows a specific example of the operating characteristic curve of the control device described above. [Figure 5] A flowchart shows an example of the operation of the above control device. [Figure 6] This waveform diagram illustrates an example of the operation of the above-mentioned control device. [Figure 7] This waveform diagram illustrates another example of operation of the above-mentioned control device. [Modes for carrying out the invention]

[0013] [Embodiment] One embodiment of this disclosure will be described in detail below.

[0014] (Configuration of the power system to which semiconductor interruption system 1 is applied) Figure 1 is a schematic diagram showing a control device 3 and a semiconductor interruption system 1 equipped therewith according to one embodiment of the present disclosure. As shown in Figure 1, the semiconductor interruption system 1 of this embodiment has a power supply 51 electrically connected to its input side and a load 52 electrically connected to its output side. In the following description, the semiconductor interruption system 1 of this embodiment will be described using an example where it is applied to a DC power system K.

[0015] The semiconductor circuit breaker system 1 of this embodiment is a system that appropriately interrupts DC power from the power supply 51, and the semiconductor circuit breaker system 1 is a semiconductor circuit breaker that interrupts the current from the power supply 51 to the load 52. Note that the power supply 51 is not limited to a DC power supply, but may also be an AC power supply. However, if the power supply 51 is an AC power supply, an AC-DC converter is installed between it and the semiconductor circuit breaker system 1, and the AC power from the power supply 51 is converted to DC power by the AC-DC converter and supplied to the semiconductor circuit breaker system 1.

[0016] The load 52 is a device that operates with direct current power. The load 52 is provided with an LC filter composed of a capacitor and an inductor on its input side, and is configured to stabilize the input power and counter noise. Further, the load 52 is provided with a power storage device such as a capacitor on its input side, and the power storage device is configured to compensate for the operating voltage when the supply of direct current power is interrupted. In addition to the above description, a load 52 that operates with alternating current power can be used. In this case, for example, a DC-AC converter that converts the direct current power from the semiconductor cutoff system 1 into alternating current power is installed inside the load 52.

[0017] (Configuration of the semiconductor cutoff system 1) As shown in FIG. 1, the semiconductor cutoff system 1 of the present embodiment includes a first line L1, a second line L2, a semiconductor switch 2, a control device 3, and a current sensor 4. The first line L1 connects the positive electrode (not shown) of the power supply 51 and the load 52. The second line L2 connects the negative electrode (not shown) of the power supply 51 and the load 52. The first line L1 and the second line L2 each form a part of the main line and the return line of the direct current power system K.

[0018] The semiconductor switch 2 is located between the power supply 51 and the load 52 on the first line 11, with one end connected to the power supply 51 and the other end connected to the load 52. The semiconductor switch 2 includes a semiconductor switch body 21 and a parasitic diode 22 formed on the semiconductor switch body 21. The control device 3 controls the semiconductor switch 2 using the detection result of the current sensor 4 and predetermined operating characteristic information preset in the control device 3 (details will be described later).

[0019] Also, since the other end of the semiconductor switch 2 is connected to the load 52, when DC power is supplied from the power supply 51 to the load 52 through the semiconductor switch 2, an inrush current may flow through the load 52. That is, since the load 52 is provided with a power storage device as described above, the load 52 has a capacitance component when viewed from the power supply 51. Therefore, when DC power is supplied, an inrush current, which is an excessive charging current from the power supply 51 to the power storage device of the load 52 through the semiconductor cutoff system 1, may flow.

[0020] Here, with reference to FIG. 2 as well, the semiconductor switch 2 will be specifically described. FIG. 2 is a perspective view showing the semiconductor switch 2 shown in FIG. 1 and a cooler 5 for cooling the same. For the semiconductor switch 2, for example, a bipolar transistor, a MOSFET (Metal - Oxide - Semiconductor Field - Effect Transistor), or an IGBT (Insulated Gate Bipolar Transistor) is used.

[0021] As shown in FIG. 2, the semiconductor switch 2 includes a gel - mold 20 covering the semiconductor switch body 21 and the parasitic diode 22, and four terminals 20A, 20B, 20C, and 20D. When the semiconductor switch body 21 is, for example, an NPN - type 2in1 - type bipolar transistor, for example, the terminals 20A, 20B, 20C, and 20D are electrically connected to the collector, the first emitter, the base, and the second emitter of the bipolar transistor (semiconductor switch body 21), respectively. Also, the terminals 20A and 20C are electrically connected to the power supply 51 and the control device 3, respectively, and the terminals 20B and 20D are electrically connected to the load 52.

[0022] A cooler 5 is attached to the semiconductor switch 2 to cool it. The cooler 5 comprises a cooling plate 5a and a plurality of cooling fins 5b. The cooling plate 5a and each of the plurality of cooling fins 5b are made of, for example, a metal material with high thermal conductivity and are rectangular flat plate members. As shown in Figure 2, the gel mold 20 of the semiconductor switch 2 is integrally fixed to the upper surface of the cooling plate 5a. On the other hand, the plurality of cooling fins 5b are attached to the lower surface of the cooling plate 5a at predetermined intervals. In the cooler 5, the heat generated in the semiconductor switch 2 is transferred to the plurality of cooling fins 5b via the cooling plate 5a, thereby cooling the semiconductor switch 2.

[0023] Furthermore, in the semiconductor shut-off system 1 of this embodiment, as will be described in detail later, predetermined physical constants of the cooler 5 and the permissible temperature of the semiconductor switch 2 when the cooler 5 is used are included in the predetermined operating characteristic information and are set in advance.

[0024] As shown in Figure 1, the current sensor 4 is installed between the power supply 51 and the semiconductor switch 2. The current sensor 4 is configured using an ammeter such as a known current transformer and detects the current flowing from the power supply 51 to the semiconductor switch 2. The current sensor 4 outputs its detection result to the control device 3.

[0025] (Configuration of control device 3) The control device 3 comprises a calculation unit 31, an opening / closing control unit 32, a driver 33, and a storage unit 34. The control device 3 controls the semiconductor switch 2 by outputting an instruction signal to the semiconductor switch body 21. Specifically, the control device 3 generates an instruction signal to be output to the base of the semiconductor switch 2 using predetermined operating characteristic information, which includes at least characteristic information regarding the operating characteristics of the semiconductor switch 2, and a current value obtained from the detection result of the current sensor 4. The control device 3 then controls the semiconductor switch 2 by outputting the generated instruction signal from the driver 33 to the base.

[0026] The memory unit 34 is configured, for example, using a rewritable non-volatile memory, and the predetermined operating characteristic information is stored in advance. This operating characteristic information includes, as characteristic information regarding the operating characteristics of the semiconductor switch 2, the lower limit value I%set of the current range for which the semiconductor switch 2 is required to be opened immediately. The operating characteristic information also includes (i) the collector-emitter saturation voltage characteristics of the semiconductor switch 2, (ii) information showing the relationship between the current value of the current flowing through the semiconductor switch 2 and the time for which the semiconductor switch 2 can be continuously energized at that current value, (iii) predetermined physical constants of the cooler 5, and (iv) the allowable temperature of the semiconductor switch 2 when the cooler 5 is used.

[0027] The switching control unit 32 controls the opening and closing of the semiconductor switch 2 based on the lower limit value I%set, which represents the interruption characteristics (static characteristics) of the semiconductor switch 2. In other words, the switching control unit 32 opens the semiconductor switch 2 if a current greater than or equal to the lower limit value I%set flows through the semiconductor switch 2.

[0028] The calculation unit 31 calculates the energizable time, which is the time during which the semiconductor switch 2 can be energized when a current with the specified current value is continuously supplied to it, based on the operational characteristic information stored in the storage unit 34 and the current value obtained from the detection result of the current sensor 4 (details will be described later).

[0029] The switching control unit 32 performs an overcurrent determination process based on the energizable time calculated by the calculation unit 31. Furthermore, the switching control unit 32 controls the opening and closing of the semiconductor switch 2 based on the determination result of the above determination process. That is, if the determination result of the determination process indicates that the current flowing through the semiconductor switch 2 is not an overcurrent, the switching control unit 32 determines that there is no need to open the semiconductor switch 2. Then, the switching control unit 32 maintains the semiconductor switch 2 in the ON state (closed state).

[0030] On the other hand, if the determination result of the determination process indicates that the current flowing through the semiconductor switch 2 is an overcurrent, the switching control unit 32 determines that it is necessary to immediately open the semiconductor switch 2. The switching control unit 32 then generates an instruction signal to turn off the semiconductor switch 2 and outputs this instruction signal to the base via the driver 33.

[0031] (Operation of control device 3) Next, with reference to Figures 3 to 5, an example of the operation of the control device 3 of this embodiment will be specifically described. Figure 3 is a graph showing an example of a specific waveform of the collector-emitter saturation voltage characteristic of the semiconductor switch 2. Figure 4 is a graph showing a specific example of the operating characteristic curve of the control device 3. Figure 5 is a flowchart showing an example of the operation of the control device 3.

[0032] (Collector-emitter saturation voltage characteristics) First, with reference to Figure 3, the collector-emitter saturation voltage characteristics of the semiconductor switch 2 will be explained in detail. The collector-emitter saturation voltage V is the voltage between the collector and emitter of the semiconductor switch body 21 when the semiconductor switch 2 is in the ON state, and as shown by curve 60 in Figure 3, it changes according to the current I flowing through the semiconductor switch 2. That is, curve 60 is expressed as a function of V = f(I). Furthermore, as shown by curve 60, this collector-emitter saturation voltage V does not become exactly 0V even when the current I is 0(A), but rather becomes a small value that differs for each product of the semiconductor switch body 21.

[0033] In the control device 3 of this embodiment, once the semiconductor switch body 21 of the semiconductor switch 2 is determined, the datasheet of the collector-emitter saturation voltage characteristics of the semiconductor switch 2 is pre-stored in the storage unit 34 as operating characteristic information. Furthermore, in the control device 3 of this embodiment, the calculation unit 31, as will be described in detail later, refers to the datasheet of the collector-emitter saturation voltage characteristics to calculate the energizable time, which serves as a threshold for the determination process, according to the tolerance (static characteristics) of the semiconductor switch 2.

[0034] Next, with reference to Figure 4, a basic example of operation of the control device 3 in this embodiment will be described. The region indicated by "B" in Figure 4 is the instantaneous cutoff region defined by the lower limit value I%set. Furthermore, when the calculation unit 31 detects that the current value detected by the current sensor 4 exceeds the lower limit value I%set shown by the straight line 71 in Figure 4, the switching control unit 32 immediately turns off the semiconductor switch 2.

[0035] Furthermore, the region indicated by “A” in Figure 4 is the continuous energization region in which the semiconductor switch 2 can be continuously energized with the current value detected by the current sensor 4. This continuous energization region is defined by the interruption current value I%cont, which is the threshold for the interruption operation, taking into account the time for which continuous energization is possible at the current value (I) detected by the current sensor 4. In other words, the interruption current value I%cont is determined by the magnitude of the Joule heat generated in the semiconductor switch 2 at different current values ​​(I), and therefore the time for which continuous energization is possible, according to the tolerance of the semiconductor switch 2, also differs. Specifically, as shown by curve 72 in Figure 4, the interruption current value I%cont decreases as the value of the current value (I) increases, as the operating time allowed by the semiconductor switch 2 decreases.

[0036] Furthermore, in the control device 3 of this embodiment, information showing the relationship between the current value (I) of the current flowing through the semiconductor switch 2 and the time during which the semiconductor switch 2 can be continuously energized with that current value (I), for example, a table showing the relationship between the current value (I) and the cutoff current value I%cont determined from the time corresponding to that current value (I), is pre-stored in the storage unit 34.

[0037] Next, with reference to Figure 5, an example of the operation of the control device 3 of this embodiment will be described. In the following description, the case in which the opening / closing control unit 32 outputs an instruction signal to turn on the semiconductor switch 2 via the driver 33, thereby closing the semiconductor switch 2 and allowing power to be supplied from the power supply 51 to the load 52 will be mainly described.

[0038] As shown in step S1 of Figure 5, the control device 3 receives the detection result from the current sensor 4 and measures the current flowing through the semiconductor switch 2. In other words, the control device 3 performs a current detection step in which the current sensor 4 detects the current flowing through the semiconductor switch 2. Then, the control device 3 obtains the current value I1 measured by the calculation unit 31.

[0039] Next, in the control device 3, when the calculation unit 31 acquires the current value I1, it resets a timer (not shown) that counts the time for which the current value I1 flows, that is, it sets the timer count value to 0 seconds (step S2). Next, the calculation unit 31 refers to the storage unit 34 to determine whether the acquired current value I1 is less than or equal to the corresponding cutoff current value I%cont (step S3). If the calculation unit 31 determines that the acquired current value I1 is less than or equal to the cutoff current value I%cont (YES in step S3), the calculation unit 31 proceeds to step S2.

[0040] Furthermore, the timer may be configured, for example, using hardware installed inside the control device 3, or the calculation unit 31 may perform the timer function by counting the number of clock signals input to the calculation unit 31.

[0041] On the other hand, if the calculation unit 31 determines that the acquired current value I1 is not less than or equal to the cutoff current value I%cont (NO in step S3), the calculation unit 31 determines whether the acquired current value I1 is greater than or equal to the lower limit value I%set (step S4). If the calculation unit 31 determines that the acquired current value I1 is greater than or equal to the lower limit value I%set (YES in step S4), the switching control unit 32 outputs an instruction signal to the semiconductor switch 2 via the driver 33, causing the semiconductor switch 2 to immediately perform a cutoff operation (step S9).

[0042] On the other hand, when the calculation unit 31 determines that the acquired current value I1 is not greater than or equal to the lower limit value I%set (NO in step S4), the calculation unit 31 activates the timer and starts timer counting (step S5). That is, the calculation unit 31 starts counting the energizing time during which the acquired current value I1 flows in the semiconductor switch 2.

[0043] Next, the calculation unit 31 calculates the collector-emitter voltage V1 of the semiconductor switch 2 (step S6). Specifically, the calculation unit 31 obtains the collector-emitter voltage V1 by substituting the current value I1 obtained in step S1 into the equation V=f(I), which represents the collector-emitter saturation voltage characteristic shown by curve 60 in Figure 3.

[0044] Next, the calculation unit 31 calculates the available energization time t1, which is the time during which the semiconductor switch 2 can be energized when the acquired current value I1 is continuously energized (step S7). Specifically, the calculation unit 31 calculates the available energization time t1 using the following equation (1).

[0045]

number

[0046] However, in equation (1), c and m are the specific heat and mass of the cooling plate 5a, respectively, which are predetermined physical constants of the cooler 5. Also, ΔT is the allowable temperature of the semiconductor switch 2 when the cooler 5 is used.

[0047] More specifically, the calculation unit 31 determines that the loss P1 generated in the semiconductor switch 2 when a current value I1 is applied to the semiconductor switch 2 is expressed as I1 × V1 = I1 × f(I1). Therefore, the Joule heat Q1 generated in the semiconductor switch 2 when the current value I1 is continuously applied for a maximum application time t1 is expressed as P1 × t1 = I1 × f(I1) × t1. In order to prevent thermal damage to the semiconductor switch 2 due to this Joule heat Q1 by the cooler 5, the cooling performance of the cooler 5, expressed in the numerator of equation (1), must be equal to the Joule heat Q1. That is, I1 × f(I1) × t1 = m × c × ΔT holds true. Accordingly, the calculation unit 31 can use the above equation (1) to determine the maximum application time t1 when the current value I1 is continuously applied.

[0048] In steps S5 to S7 described above, the control device 3 performs a calculation step to calculate the energizable time, which is the time during which the semiconductor switch 2 can be energized when a current having said current value is continuously supplied to the semiconductor switch 2, based on predetermined operating characteristic information that includes at least characteristic information regarding the operating characteristics of the semiconductor switch 2, and the current value obtained from the detection result of the current detection step described above.

[0049] Next, the calculation unit 31 determines whether the count time at the start of the count in step S5 has elapsed beyond the energizable time t1 calculated in step S7 (step S8). If the calculation unit 31 determines that the count time has elapsed beyond the energizable time t1 (YES in step S8), the process proceeds to step S9. As a result, the switching control unit 32 outputs an instruction signal via the driver 33 to turn off the semiconductor switch 2, causing the semiconductor switch 2 to perform a shut-off operation.

[0050] On the other hand, if the calculation unit 31 determines that the count time has not elapsed beyond the energized time t1 (NO in step S8), it returns to the step before S8. That is, the switching control unit 32 keeps the semiconductor switch 2 in the ON state without turning it OFF, allowing power to be supplied from the power supply 51 to the load 52. The calculation unit 31 also continues to perform the timer count. That is, the calculation unit 31 counts the cumulative energized time over which the current value I1 has flowed through the semiconductor switch 2.

[0051] Furthermore, while the control device 3 is counting the cumulative energizing time using the calculation unit 31, if it detects that the detection result from the current sensor 4 has fallen below the cutoff current value I%cont, it stops counting the cumulative energizing time and returns to step S1. Also, while the control device 3 is counting the cumulative energizing time, if it detects that the detection result from the current sensor 4 has fallen above the lower limit value I%set, the switching control unit 32 immediately causes the semiconductor switch 2 to perform a cutoff operation.

[0052] In steps S8 to S9 described above, the control device 3 performs an opening / closing control step, which controls the opening and closing of the semiconductor switch 2 based on the energizable time calculated in the calculation step.

[0053] The control device 3 of this embodiment, configured as described above, includes a calculation unit 31 that calculates the energizable time, which is the time during which the semiconductor switch 2 can be energized when a current having that current value is continuously supplied to the semiconductor switch 2, based on predetermined operational characteristic information, which includes at least characteristic information regarding the operational characteristics of the semiconductor switch 2, and the current value obtained from the detection result of the current sensor 4. Furthermore, the control device 3 of this embodiment includes an opening / closing control unit 32 that controls the opening and closing of the semiconductor switch 2 based on the energizable time calculated by the calculation unit 31. As a result, in the control device 3 of this embodiment, the opening / closing control unit 32 can perform an overcurrent determination process using the energizable time calculated by the calculation unit 31 as a threshold value to control the opening and closing of the semiconductor switch 2.

[0054] Furthermore, since the control device 3 of this embodiment performs the determination process using the operating characteristic information of the semiconductor switch 2, it is possible to standardize the threshold (energizable time) according to the semiconductor switch 2. As a result, the control device 3 of this embodiment can appropriately set the threshold regardless of the electrical characteristics of the power supply 51 and the load 52 electrically connected to the semiconductor switch 2, thereby reducing the possibility of erroneous determination in the determination process.

[0055] Furthermore, in the control device 3 of this embodiment, the calculation unit 31 calculates the energizable time using the cooling performance of the cooler 5, so the switching control unit 32 can perform highly accurate determination processing more reliably. In other words, the switching control unit 32 can suppress thermal damage to the semiconductor switch 2 while ensuring that the semiconductor switch 2 performs the shut-off operation appropriately.

[0056] Furthermore, in the control device 3 of this embodiment, the calculation unit 31 calculates the energization time as a threshold using the collector-emitter saturation voltage characteristics shown by the curve 60 in Figure 3. Therefore, the calculation unit 31 can determine the threshold by considering the relationship between the current value and the energization time. As a result, in the control device 3 of this embodiment, the threshold can also be used as a setting value to prevent thermal damage to the semiconductor switch 2 due to Joule heating, and the occurrence of such thermal damage can be reliably suppressed.

[0057] Here, the effects of the control device 3 of this embodiment will be specifically explained with reference to Figures 6 and 7. Figure 6 is a waveform diagram illustrating an example of the operation of the control device 3. Figure 7 is a waveform diagram illustrating another example of the operation of the control device 3. Note that in Figures 6 and 7, the lower limit value I%set, which causes the switching control unit 32 to immediately perform a shutoff operation, is not shown.

[0058] The current flowing through the semiconductor switch 2 rises sharply from time T1, as shown by the solid line 81 in Figure 6, and becomes greater than or equal to the interruption current value I%cont at time T2. Furthermore, when this current becomes less than or equal to the interruption current value I%cont at time T3, the calculation unit 31 determines that the timer count value from time T1 to time T3 has not exceeded the energizable time determined by this current. As a result, in the control device 3 of this embodiment, the switching control unit 32 continues to energize the semiconductor switch 2 through the semiconductor switch 2 even after time T3 without causing the semiconductor switch 2 to perform an interruption operation.

[0059] On the other hand, the current flowing through the semiconductor switch 2 rises sharply from time T11, as shown by the solid line 82 in Figure 7, and exceeds the cutoff current value I%cont at time T12. Furthermore, when the calculation unit 31 determines that the cumulative time count value from time T11 has exceeded the energizable time at time T13, the switching control unit 32 immediately causes the semiconductor switch 2 to perform a cutoff operation, stopping the energization through the semiconductor switch 2 at time T13.

[0060] Furthermore, in the control device 3 of this embodiment, as is clear from the solid line 81 in Figure 6, when an inrush current during the activation of the power system, or an overcurrent due to noise interference in the current sensor 4, flows through the semiconductor switch 2 for a short period of time, the control device 3 can prevent the semiconductor switch 2 from opening due to unnecessary overcurrent detection. In addition, since the energizable time is used as the threshold value in the control device 3 of this embodiment, it is possible to suppress erroneous judgments in the judgment process not only when short-term overcurrents like those described above occur, but also when an overcurrent without a sharp peak flows, and to suppress the occurrence of thermal damage to the semiconductor switch 2.

[0061] In the above description, a configuration was described in which predetermined operating characteristic information is set in the storage unit 34 and stored in advance. However, this disclosure is not limited to this, and a configuration in which the operating characteristic information is set as appropriate from an external device such as a server via a communication interface provided in the semiconductor blocking system 1 is also possible.

[0062] [Examples of implementation using software] The function of the control device 3 (hereinafter referred to as "device") is a program for causing the device to function as a computer, and can be realized by a control program for causing the device to function as a control block (in particular, the calculation unit 31 and the opening / closing control unit 32) as a computer.

[0063] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., memory) as hardware for executing the control program. By executing the control program using this control device and storage device, each of the functions described in each of the embodiments is realized.

[0064] The control program described above may be recorded on one or more computer-readable recording media, not temporary ones. These recording media may or may not be provided by the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0065] Furthermore, some or all of the functions of each of the above control blocks can also be realized by logic circuits. For example, an integrated circuit in which logic circuits functioning as each of the above control blocks are formed is also included in the scope of the present invention. In addition, it is also possible to realize the functions of each of the above control blocks by, for example, a quantum computer.

[0066] The recording medium described above can be a "non-temporary, tangible medium," such as ROM (Read Only Memory), as well as tape, disk, card, semiconductor memory, programmable logic circuit, etc. It may also further include RAM (Random Access Memory) for deploying the program. The program may also be supplied to the computer via any transmission medium capable of transmitting the program (such as a communication network or broadcast waves). In one aspect of the present invention, the program can also be realized in the form of a data signal embedded in a carrier wave, which is embodied by electronic transmission.

[0067] Furthermore, each process described in the above embodiment may be performed by AI (Artificial Intelligence). In this case, the AI ​​may operate on the control device described above, or it may operate on other devices (for example, an edge computer or a cloud server).

[0068] 〔summary〕 To solve the above problems, a control device according to Embodiment 1 of the present disclosure is a semiconductor system comprising: a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load; and a current sensor for detecting the current flowing from the power source to the semiconductor switch, wherein the control device controls the semiconductor switch and comprises: a calculation unit that calculates an energizable time, which is the time during which the semiconductor switch can be energized when a current having said current value is continuously supplied to the semiconductor switch, based on predetermined operating characteristic information, which includes at least characteristic information relating to the operating characteristics of the semiconductor switch, and a current value obtained from the detection result of the current sensor; and an opening / closing control unit that controls the opening and closing of the semiconductor switch based on the energizable time calculated by the calculation unit.

[0069] With the above configuration, the switching control unit can perform overcurrent determination processing using the energizing time calculated by the calculation unit as a threshold, thereby controlling the switching of the semiconductor switch. As a result, the control device can appropriately change the threshold in the determination processing according to the energizing time and the operating characteristics of the semiconductor switch, thereby reducing the possibility of misjudgment. Furthermore, since the control device performs the determination processing using the operating characteristic information of the semiconductor switch, it is possible to standardize the threshold according to the semiconductor switch, and regardless of the electrical characteristics of the power supply electrically connected to the semiconductor switch and the electrical characteristics of the load, the threshold can be appropriately set, thereby reducing the possibility of misjudgment in the determination processing.

[0070] Furthermore, in the control device according to Embodiment 2 of the present disclosure, in Embodiment 1, the semiconductor system further comprises a cooler for cooling the semiconductor switch, the operating characteristic information includes a predetermined physical constant of the cooler and an acceptable temperature of the semiconductor switch when the cooler is used, the calculation unit calculates the energizable time using the predetermined physical constant and the acceptable temperature, and the operating characteristic information includes a lower limit of the current range in which the semiconductor switch is required to be opened immediately, and the opening / closing control unit may open the semiconductor switch if a current of the lower limit or more flows through the semiconductor switch.

[0071] With the above configuration, the calculation unit calculates the energizable time using the cooling performance of the cooler, allowing the switching control unit to perform highly accurate judgment processing more reliably. Furthermore, the operating characteristic information includes the interruption characteristics (static characteristics) of the semiconductor switch, indicated by the lower limit of the current range in which the semiconductor switch is required to open immediately. For this reason, the switching control unit can set the threshold more appropriately regardless of the electrical characteristics of the power supply electrically connected to the semiconductor switch and the electrical characteristics of the load, making highly accurate judgment processing easier.

[0072] Furthermore, in embodiment 3 of the present disclosure, the control device further comprises a cooler for cooling the semiconductor switch in embodiment 1 or embodiment 2, wherein the semiconductor system further comprises a cooler for cooling the semiconductor switch, and the operating characteristic information includes (i) the collector-emitter saturation voltage characteristic of the semiconductor switch, (ii) information showing the relationship between the current value of the current flowing through the semiconductor switch and the time for which the semiconductor switch can be continuously energized at that current value, (iii) predetermined physical constants of the cooler, and (iv) the allowable temperature of the semiconductor switch when the cooler is used, and the calculation unit may calculate the energization time using the collector-emitter saturation voltage characteristic, the information showing the relationship, the predetermined physical constants, and the allowable temperature.

[0073] With the above configuration, the calculation unit calculates the energizing time considering the cooling performance of the cooler, so the switching control unit can perform highly accurate judgment processing more reliably. In addition, the operating characteristic information includes the collector-emitter saturation voltage characteristics of the conductor switch, the current value of the current flowing through the semiconductor switch, and information showing the relationship between that current value and the time for which the semiconductor switch can be continuously energized. As a result, the calculation unit can calculate the energizing time as a threshold for the judgment processing according to the tolerance (static characteristics) of the semiconductor switch. For this reason, the switching control unit can set the threshold more appropriately regardless of the electrical characteristics of the power supply electrically connected to the semiconductor switch and the electrical characteristics of the load, and can easily perform highly accurate judgment processing.

[0074] Furthermore, the semiconductor interruption system according to Embodiment 4 of this disclosure includes a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load; a current sensor that detects the current flowing from the power source to the semiconductor switch; and a control device according to any one of Embodiments 1 to 3.

[0075] Furthermore, in the semiconductor interruption system according to aspect 5 of this disclosure, in aspect 4, a bipolar transistor, a MOSFET, or an IGBT may be used for the semiconductor switch.

[0076] Furthermore, a control method for a semiconductor switch according to aspect 6 of the present disclosure is a control method for controlling a semiconductor switch in a semiconductor system comprising: a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts current from the power source to the load; and a current sensor that detects current flowing from the power source to the semiconductor switch, the control method comprising: a current detection step in which the current sensor detects current flowing through the semiconductor switch; a calculation step in which a current that has a given current value is continuously supplied to the semiconductor switch, based on predetermined operating characteristic information that includes at least characteristic information relating to the operating characteristics of the semiconductor switch and a current value obtained from the detection result of the current detection step, the calculation step in which an energizable time is calculated, which is the time that energizable is possible when a current having that current value is continuously supplied to the semiconductor switch; and an opening / closing control step in which the opening and closing of the semiconductor switch is controlled based on the energizable time calculated in the calculation step.

[0077] Furthermore, the control program according to embodiment 7 of this disclosure is a control program for causing a computer to function as a control device according to any of embodiments 1 to 3, wherein the computer functions as the calculation unit and the opening / closing control unit.

[0078] Furthermore, the recording medium according to aspect 8 of this disclosure is a computer-readable recording medium on which the control program of aspect 7 is recorded.

[0079] According to the configurations of embodiments 4 to 8, the same effects as in embodiment 1 are achieved.

[0080] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of this disclosure. [Explanation of Symbols]

[0081] 1. Semiconductor Blocking System 2. Semiconductor switches 3. Control device 31 Calculation Section 32 Opening / Closing Control Unit 4 Current Sensor 5. Cooler 51 Power Supply 52 load

Claims

1. A semiconductor switch, with one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load, A semiconductor interruption system comprising a current sensor for detecting the current flowing from the power supply to the semiconductor switch, wherein a control device for controlling the semiconductor switch, The control device is A calculation unit calculates the energizable time, which is the time during which the semiconductor switch can be energized when a current having that current value is continuously supplied to the semiconductor switch, based on predetermined operating characteristic information that includes at least characteristic information relating to the operating characteristics of the semiconductor switch and a current value obtained from the detection result of the current sensor. The system includes an opening / closing control unit that controls the opening and closing of the semiconductor switch based on the energizable time calculated by the calculation unit, The semiconductor shutdown system further comprises a cooler for cooling the semiconductor switch, The aforementioned operating characteristic information includes: (i) The collector-emitter saturation voltage characteristics of the semiconductor switch, (ii) Information showing the relationship between the current value of the current flowing through the semiconductor switch and the time for which the semiconductor switch can be continuously energized with that current value, (iii) The predetermined physical constants of the cooler, (iv) The permissible temperature of the semiconductor switch when the cooler is used, The calculation unit is a control device that calculates the energizable time using the collector-emitter saturation voltage characteristics, information indicating the relationship, predetermined physical constants, and the allowable temperature.

2. The operating characteristic information includes a lower limit of the current range in which the semiconductor switch is required to be opened immediately. The control device according to claim 1, wherein the switching control unit opens the semiconductor switch when a current exceeding the lower limit flows through the semiconductor switch.

3. A semiconductor switch, with one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load, A current sensor for detecting the current flowing from the power supply to the semiconductor switch, A semiconductor shutoff system comprising the control device according to claim 1 or 2.

4. The semiconductor interruption system according to claim 3, wherein the semiconductor switch is a bipolar transistor, a MOSFET, or an IGBT.

5. A semiconductor interruption system comprising a semiconductor switch having one end connected to a power source and the other end connected to a load, which interrupts the current from the power source to the load, and a current sensor which detects the current flowing from the power source to the semiconductor switch, wherein a control method for controlling the semiconductor switch is provided, The control method described above is The current detection step involves detecting the current flowing through the semiconductor switch using the current sensor, A calculation step to calculate the energizable time, which is the time during which the semiconductor switch can be energized when a current having the said current value is continuously supplied to the semiconductor switch, based on predetermined operating characteristic information, which includes at least characteristic information relating to the operating characteristics of the semiconductor switch, and a current value obtained from the detection result of the current detection step. The process includes a switching control step which controls the opening and closing of the semiconductor switch based on the energizable time calculated in the calculation step, The semiconductor shutdown system further comprises a cooler for cooling the semiconductor switch, The aforementioned operating characteristic information includes: (i) The collector-emitter saturation voltage characteristics of the semiconductor switch, (ii) Information showing the relationship between the current value of the current flowing through the semiconductor switch and the time for which the semiconductor switch can be continuously energized with that current value, (iii) The predetermined physical constants of the cooler, (iv) The permissible temperature of the semiconductor switch when the cooler is used, A method for controlling a semiconductor switch, comprising the calculation step of calculating the energizable time using the collector-emitter saturation voltage characteristics, information indicating the relationship, a predetermined physical constant, and the allowable temperature.

6. A control program for causing a computer to function as a control device according to claim 1 or 2, wherein the computer functions as the calculation unit and the opening / closing control unit.

7. A computer-readable recording medium that stores the control program described in claim 6.

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