JPH1014278A - Transformer apparatus controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a high load controllability in an overcurrent at the time of over voltage impressing and at the time of overcurrent flowing, without significantly increasing the size and the manufacturing cost. SOLUTION: A low-rated IGBT 11, a high-rated IGBT 12, and a DC motor 10 are connected in series, and both its ends are connected to a positive power source 1 and a negative power source 2, respectively. For the low-rated IGBT 11, one having a maximum rated voltage V11 and a maximum rated current I11 , larger than a maximum voltage Vmax , and a maximum current Imax to be presumed to be generated in the IGBT respectively, is selected. The values of the maximum voltage Vmax and the maximum current Imax are found by experiments or analysis, from the constants of the DC motor 10 and other circuit elements. For the high-rated IGBT 12, one having a maximum rated voltage V12 and a maximum rated current, I12 larger than the maximum rated voltage V11 and the maximum rated current I11 of the low-rating IGBT 11 respectively, is selected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substation control apparatus for driving and controlling loads such as motors and coils used in substation equipment by semiconductor elements.

[0002]

2. Description of the Related Art Substation equipment such as gas insulated switchgear is
It has a DC motor, AC motor, coil, etc. for operating the device. These motors and coils are controlled by a control device installed near the substation equipment. In this case, since the substation device is an important public device, the control device is required to perform highly reliable control to minimize the possibility of malfunction or inoperability.

Conventionally, mechanical contacts such as relays have been used as the contacts of such substation equipment control devices. However, from the viewpoint of reducing malfunctions and inoperability due to wear of the contacts, semiconductor devices have recently been used. Is being applied.

That is, when a semiconductor element is applied as a contact of a substation control device, there is an advantage that the load can be controlled without causing a mechanical problem such as contact wear since the semiconductor element has no movable parts. In addition, semiconductor elements are relatively inexpensive and are excellent in economic efficiency. However, on the other hand, the semiconductor element also has a disadvantage that it is relatively vulnerable to overvoltage, overcurrent, and heating.

Therefore, when a semiconductor element is applied to a substation control device, the element may be relatively inexpensive as described above in order to improve reliability, and a plurality of semiconductor elements are connected in series. There are cases. FIG. 7 shows the positive power supply 1
The two semiconductor elements 3a and 3b are connected in series between the power supply and the negative power supply 2, and the two semiconductor elements 3a and 3b are simultaneously turned on or off, so that one control object 1 shows a substation control device configured to control a load 4. In other words, in the device shown in FIG. 7, the two semiconductor elements 3a and 3b are simultaneously turned on or off, so that even if one of the semiconductor elements 3a is short-circuited, the other semiconductor element 3a, 3b is short-circuited. If the element 3b is sound, malfunction of the load can be prevented.

[0006]

As shown in FIG. 7, when a plurality of semiconductor elements 3 are used as the contacts of the substation control device, the same type of elements are used, and the maximum rating of the elements is obtained. Are all the same. The value of this maximum rating is determined in consideration of various standards and load characteristics.
It is determined to withstand the expected maximum voltage value and current value.

However, if an overvoltage or an overcurrent exceeding the maximum rating determined in this way is applied to the control device, all the elements may fail at the same time. In this case, since the failure of the semiconductor element is usually a short-circuit failure, once all the elements have failed, the current flowing to the load cannot be cut off and the load cannot be stopped. This inability to stop the load is a serious situation in which the control of substation equipment that handles large energy becomes impossible, and must be avoided. On the contrary,
It is conceivable to use an element having an extremely large maximum rating. However, in this case, although the reliability can be improved, it is not preferable because the control device is increased in size and the manufacturing cost is increased.

[0008] The present invention has been proposed to solve the problems of the prior art as described above.
To provide a small, economical, and highly reliable substation control device that can ensure high load control capability when overvoltage is applied or overcurrent is applied without significantly increasing the size and manufacturing cost. It is.

[0009]

In order to achieve the above object, a substation control apparatus according to the present invention connects a plurality of semiconductor elements in series, and simultaneously switches the plurality of semiconductor elements to a state in which current can be supplied or a state in which conduction is prevented. By doing so, in the substation equipment control device that controls the energization to the control target load,
It is characterized in that a plurality of semiconductor elements or elements having different ratings and capabilities are used as their accessory elements. And, by using a plurality of semiconductor elements or ones with different ratings and capabilities as their accessory elements,
The possibility that all the semiconductor elements or their attached components will fail at the same time can be remarkably reduced as compared with the case where the elements having the same rating and capability are used.

[0010] The invention according to claim 1 is characterized in that semiconductor elements having different maximum ratings are used. That is, in the invention of claim 1,
The plurality of semiconductor elements include a plurality of types of semiconductor elements having different maximum ratings, and the first type of semiconductor element has a higher maximum rating than the second type of semiconductor elements. In the following, for the sake of convenience, the first type semiconductor element having a large maximum rating and the second type semiconductor element having a small maximum rating are referred to as a high-rated semiconductor element and a low-rated semiconductor element, respectively. .

According to the first aspect of the present invention having the above configuration, even if an overvoltage or an overcurrent exceeding the design value is applied to the substation equipment control device, the overvoltage or the overcurrent value becomes high. As long as it is smaller than the maximum rating of the rated semiconductor device, at least the failure of the high-rated semiconductor device can be avoided, so that the load control capability is maintained. Therefore, the limit of the voltage value or the current value that can maintain the load control ability can be increased as compared with the case where the maximum ratings of all the semiconductor elements are the same. In the following, for the sake of convenience, the characteristics of the upper limit voltage value and the current value at which the load control capability of the control device can be maintained are referred to as control limit voltage characteristics and control limit current characteristics, respectively.

As described above, in the present invention, by using a high-rated semiconductor element only for some of the semiconductor elements, the control limit voltage characteristic can be reduced in the same manner as when all the semiconductor elements are used. In addition, control limit current characteristics can be improved. Further, it is possible to suppress an increase in the size and manufacturing cost of the control device as compared with a case where a high-rated semiconductor element is used for all the semiconductor elements. Therefore, according to the present invention, it is possible to secure a high load control ability at the time of overvoltage application or overcurrent application without significantly increasing the size and manufacturing cost of the control device.

In the present invention, the failure of the semiconductor device can be determined in an operating state by measuring the voltage between the electrodes of the device. Therefore, when the low-rated semiconductor element breaks down, appropriate measures such as replacement of the faulty element can be taken at an early stage by automatically generating an alarm based on a change in the voltage between the electrodes.

According to a second aspect of the present invention, semiconductor devices of different types having different maximum rated voltages and maximum rated currents are used. That is, in the invention described in claim 2, the plurality of semiconductor elements include a plurality of types of semiconductor elements having different maximum rated voltages and maximum rated currents. The first type of semiconductor element has a higher maximum rated voltage than the second type of semiconductor element, and the second type of semiconductor element has a higher maximum rated current than the first type of semiconductor element. . In the following, for the sake of convenience, a first type semiconductor element having a large maximum rated voltage and a second type semiconductor element having a large maximum rated current are referred to as a high withstand voltage type semiconductor element and a high withstand current type semiconductor, respectively. It shall be called an element.

According to the second aspect of the present invention having the above structure, even if an overvoltage or an overcurrent is applied to the substation equipment control device, the overvoltage is higher than the maximum rated voltage of the high withstand voltage type semiconductor element. As long as it is small or the overcurrent is smaller than the maximum rated current of the high withstand current type semiconductor device,
Since the failure of at least one of the high withstand voltage type semiconductor element and the high withstand current type semiconductor element can be avoided, the load control ability is maintained.

In general, it is difficult for a semiconductor element to have both a high maximum rated voltage and a large maximum rated current if the external dimensions are the same, and a high withstand voltage element having a high maximum rated voltage has a maximum rated current. Is relatively small, and a high withstand current element having a high maximum rated current has a relatively small maximum rated voltage. According to the present invention, by using such two types of semiconductor elements in combination in series,
By utilizing the characteristics of each element synergistically, the control limit voltage characteristics and the control limit current characteristics of the entire control device can be improved. Then, it is possible to suppress an increase in the size and manufacturing cost of the control device as compared with a case where the maximum rated voltage and the maximum rated current of all the semiconductor elements are increased.

Therefore, according to the present invention, similarly to the first aspect of the present invention, a high load control capability can be ensured when an overvoltage is applied or an overcurrent is applied without significantly increasing the size and manufacturing cost of the control device. it can. In the present invention, as in the first aspect of the present invention, the failure can be determined in the operating state by measuring the voltage between the electrodes of the semiconductor element. Can be implemented early.

According to a third aspect of the present invention, as the overvoltage protection circuit of the semiconductor device, a circuit having a different protection capability is used. That is, in the invention according to claim 3, the plurality of semiconductor elements include a plurality of types of semiconductor elements having different protection capabilities of the overvoltage protection circuit, and the first type of semiconductor element is more protected than the second type of semiconductor element. It has a high performance overvoltage protection circuit. In the following,
For convenience, a semiconductor element having a high protection ability of the overvoltage protection circuit and a semiconductor element having a low protection ability of the overvoltage protection circuit are referred to as a heavy protection semiconductor element and a light protection semiconductor element, respectively.

According to the third aspect of the present invention having the above configuration, even if an overvoltage exceeding the design value is applied to the substation equipment control device, the overvoltage is applied to the overvoltage protection circuit of the heavy protection semiconductor element. As long as the protection capability is not exceeded, at least the failure of the heavy protection semiconductor device can be avoided, so that the load control capability is maintained.

As described above, in the present invention, by using the heavy protection semiconductor element only for some of the semiconductor elements, the limit limit can be obtained as in the case where the heavy protection semiconductor element is used for all the semiconductor elements. The voltage characteristics can be improved, and the reliability of the control device can be improved. Therefore, an increase in the size and manufacturing cost of the control device can be suppressed as compared with the case where the heavy protection semiconductor elements are used for all the semiconductor elements.

Therefore, according to the present invention, the control limit voltage characteristic can be improved without significantly increasing the size and manufacturing cost of the control device, and high load control capability can be secured. In the present invention, as in the first aspect of the present invention, the failure can be determined in the operating state by measuring the voltage between the electrodes of the semiconductor element. Can be implemented early.

According to a fourth aspect of the present invention, a radiator having a different heat radiation capability is used as the radiator of the semiconductor element. That is, in the invention according to claim 4, the plurality of semiconductor elements include a plurality of types of semiconductor elements having different heat radiation capabilities of the radiator, and the first type of semiconductor element has a higher heat radiation capacity than the second type of semiconductor element. With a high radiator. In addition, since the level of the heat radiation capability is generally determined by the size of the radiator, a semiconductor device having a high heat radiation capability and a semiconductor device having a low heat radiation capability will be described below for convenience. Are called a semiconductor element with a large radiator and a semiconductor element with a small radiator, respectively.

According to the fourth aspect of the present invention having the above-described configuration, even if an overcurrent or a thermal abnormality exceeding the design value is applied to the substation equipment control device, the amount of heat is reduced by the large radiator. As long as the heat dissipation capability of the semiconductor device with the heat sink is not exceeded, at least the failure of the semiconductor device with the large heat sink can be avoided, so that the load control capability is maintained.

As described above, according to the present invention, by using the semiconductor element with the large radiator only for some of the semiconductor elements, the same as the case where the semiconductor element with the large radiator is used for all the semiconductor elements. In addition, the limiting current characteristics and the heat resistance can be improved, and the reliability of the control device can be improved. Therefore, an increase in the size and manufacturing cost of the control device can be suppressed as compared with the case where a large radiator is used for all the semiconductor elements.

Therefore, according to the present invention, the limiting current characteristics and the heat resistance can be improved without significantly increasing the size and manufacturing cost of the control device, and a high load control capability can be secured. In the present invention, as in the first aspect of the present invention, the failure can be determined in the operating state by measuring the voltage between the electrodes of the semiconductor element. Can be implemented early.

According to a fifth aspect of the present invention, in the first, third, or fourth aspect of the invention, when a plurality of loads to be controlled are used, a plurality of individual semiconductor elements and a single common semiconductor element are used. It is characterized by doing. That is, in the invention according to claim 5, the load to be controlled is a plurality of loads, and the plurality of semiconductor elements include a plurality of individual semiconductor elements respectively connected in series to the plurality of loads, and the individual semiconductor element. It has a single common semiconductor element connected in series to the elements collectively. And the single common semiconductor element and the plurality of individual semiconductor elements are defined in claim 1,
The semiconductor device according to the third or fourth aspect has a relationship between the first and second types of semiconductor elements.

According to the fifth aspect of the present invention having the above-described structure, a plurality of relatively low-performance semiconductor elements are replaced by a single common high-performance semiconductor element, thereby providing a plurality of loads. As in the case where a high-performance semiconductor element is used for all of the plurality of individual semiconductor elements, the limiting voltage characteristics and the limiting current characteristics can be improved. Further, it is possible to suppress an increase in the size and manufacturing cost of the control device as compared with a case where a large-sized high-performance semiconductor element is used for all of the plurality of individual semiconductor elements for a plurality of loads. Therefore, according to the present invention, in particular, for a plurality of loads, similar to the first, third, or fourth aspect of the present invention, when the overvoltage is applied without significantly increasing the size and manufacturing cost of the control device. High load control ability at the time of overcurrent application can be secured.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION

[1. First Embodiment] [1-1. Configuration] FIG. 1 is a basic circuit diagram showing one embodiment of a substation control apparatus to which the invention of claim 1 is applied as a first embodiment of the present invention. This figure 1
, 10 is a DC motor which is a load to be controlled, 11
Is a low-rated IGBT (insulated gate bipolar transistor) having a small maximum rating, and 12 is a high-rated I having a large maximum rating.
GBT. That is, as shown in FIG.
GBT 11, high rated IGBT 12, and DC motor 1
0 are connected in series, and both ends thereof are connected to a positive power supply 1 and a negative power supply 2, respectively. In addition, like this,
The reason why the low-rated IGBT 11 and the high-rated IGBT 12 are connected in series is to enable control of the DC motor 10 even when one of the IGBTs is short-circuited.

In this case, the low-rated IGBT 11 is selected such that its maximum rated voltage V ₁₁ and maximum rated current I ₁₁ are respectively larger than the maximum voltage V _max and the maximum current I _max expected to be generated in the IGBT. Have been. Here, the maximum voltage V _max and a maximum current I _max
Is determined by experiments and analysis from the constants of the DC motor 10 and other circuit elements. In addition, high rated IGB
T12 has its maximum rated voltage V ₁₂ and the maximum rated current I
_12, are selected so that each is larger than the maximum rated voltage V ₁₁ and the maximum rated current I ₁₁ of the lower rating IGBT 11.

That is, the two IGBTs 11 and 12 are:
Its maximum rated voltage V ₁₁ , V ₁₂ and maximum rated current I ₁₁ ,
I ₁₂ is selected so as to have the relationship of the following equation (1).

(Equation 1)

[1-2. Operation] According to the present embodiment having the above configuration, even when an overcurrent or an overvoltage is applied to the control device, the load control ability can be sufficiently maintained. Hereinafter, this operation will be specifically described.

[0032] For example, in the control apparatus of the present embodiment, the insufficient precision probabilistic factors such experiments and analysis, the current I exceeds the maximum current I _max to be expected each IGBT1
Let us consider the case where the flow has reached 1 and 12. Here, if the value of the current I is I ₁₂ >I> I ₁₁ , the low-rated IGBT 11 fails, and the failure mode is generally a short-circuit failure. However, since the high-rated IGBT 12 does not fail, the DC motor 10 can be stopped. That is, although a failure occurs, the load stopping ability is not lost.

In the control device according to the present embodiment,
Voltage V that exceeds the maximum voltage V _max to be expected the IGBT
11 and 12, the value of the voltage V becomes V ₁₂
If>V> V _11, the lower rating IGBT11 is failed but the high rated IGBT12 so does not lead to failure, even in this case, it is possible to stop the DC motor 10.

The failure of the low-rated IGBT 11 when the overcurrent is applied or the overvoltage is applied can be quickly detected during operation by measuring the voltage between the electrodes.
Countermeasures such as alarm display are possible.

On the other hand, in the control device of this embodiment,
The value of the current I exceeds the maximum current I _max to be expected I> I
₁₂ is either or if the value of the voltage V which exceeds the maximum voltage V _max, which is expected to V> a V _12, high rated IGBT1
2 also fails, and the DC motor 10 cannot be stopped. However,
Set sufficiently larger than the maximum current I _max to the expected value of the maximum rated current I ₁₂ of the high rated IGBT 12, and set sufficiently larger than the maximum voltage V _max to the expected value of the maximum rated voltage V ₁₂ If so, the possibility of falling into such a situation can be extremely reduced.

[1-3. Effect] As described above, according to the present embodiment, only one high-rated IGBT is used,
The same high control limit voltage characteristics and control limit current characteristics as when two high-rated IGBTs are used in series can be achieved. Therefore, as compared with the case where two low-rated IGBTs are connected in series, the possibility that the substation equipment becomes uncontrollable is reduced, and high load control capability can be secured. Further, compared to a case where two high-rated IGBTs are connected in series, it is possible to suppress an increase in the size and manufacturing cost of the control device.

More specifically, some DC motors used in gas-insulated switchgear have a starting current of 25 A at the maximum. When a low-rated IGBT and a high-rated IGBT for controlling such a DC motor are selected, their outer dimensions are as shown in Table 1 below, for example.

[0038]

[Table 1]

As can be seen from Table 1, high rated IGB
T has a considerably larger outer dimension than a low-rated IGBT. Also, prices are usually quite high. For this reason, according to the present embodiment in which one high-rated IGBT and one low-rated IGBT are used, it is possible to suppress an increase in the size and manufacturing cost of the control device as compared with a case where two high-rated IGBTs are connected in series. Clearly what you can do.

Therefore, according to the present embodiment, it is possible to secure a high load control capability at the time of overvoltage application or overcurrent application without significantly increasing the size and manufacturing cost of the control device. In other words, the reliability of the substation control device can be greatly improved while maintaining the miniaturization and economical efficiency.

[1-4. Modified Example] In the present embodiment, the case where the invention described in claim 1 is applied to the maximum rated current and the maximum rated voltage has been described.
As a modification of the present embodiment, a configuration in which the invention described in claim 1 is applied to other ratings such as a pulse rated current and a maximum collector loss is also possible. In that case, the same operation and effect can be obtained. it can.

[2. Second Embodiment] [2-1. Configuration] FIG. 2 is a basic circuit diagram showing one embodiment of a substation control apparatus to which each of the inventions according to claims 1 and 5 is applied as a second embodiment of the present invention. In FIG. 1, separate low-rated IGBTs 11 are provided for two DC motors 10a and 10b which are loads to be controlled.
a and 11b are connected in series, respectively, and a single common high-rated IGBT 12 is connected in series to the two low-rated IGBTs 11a and 11b. The end on the high-rated IGBT 12 side and the end on the DC motor 10a, 10b side are connected to a positive power supply 1 and a negative power supply 2, respectively. In the present embodiment, the low-rated IGBT 11
The maximum rated voltage and the maximum rated current of the a and 11b and the high-rated IGBT 12 are selected in exactly the same manner as in the first embodiment.

[2-2. Operation / Effect] According to the present embodiment having the above configuration, when an overcurrent or an overvoltage is applied to the control device, one or both of the plurality of individual low-rated IGBTs 11a and 11b fail. Even if it does, similar to the first embodiment,
The possibility of failure of the common high-rated IGBT 12 can be extremely reduced.

Therefore, the two DC motors 10a, 1
In contrast to Ob, high load control capability can be ensured during overvoltage application or overcurrent application without significantly increasing the size and manufacturing cost of the control device. That is, similarly to the first embodiment, it is possible to greatly improve the reliability while maintaining the miniaturization and economy of the substation device control device.

[3. Third Embodiment] [3-1. Configuration] FIG. 3 is a basic circuit diagram showing one embodiment of a substation control apparatus to which the invention of claim 2 is applied as a third embodiment of the present invention. This figure 3
, 21 is a high withstand voltage type IG having a large maximum rated voltage.
BT, 22 is a high withstand current type IGBT with a large maximum rated current
It is. That is, as shown in FIG.
The BT21, the high withstand current type IGBT22, and the DC motor 10 are connected in series, and both ends are connected to the positive power supply 1 and the negative power supply 2, respectively.

In this case, the high withstand voltage type IGBT ₂₁ is selected such that the maximum rated current I ₂₁ is larger than the maximum current I _max expected to occur in the IGBT. The high withstand current type IGBT22, the maximum rated voltage V ₂₂ has been chosen to be greater than the maximum voltage V _max, which is expected to occur in the IGBT. Further, the high withstand voltage type IGBT 21 and the high withstand current type IGBT 22 are such that the maximum rated voltage V ₂₁ of the high withstand voltage type IGBT ₂₁ is larger than the maximum rated voltage V ₂₂ of the high withstand voltage type IGBT ₂₂ and the high withstand voltage type IGBT ₂₂ maximum rated current I ₂₂ is the maximum rated current I of the high withstand voltage type IGBT21
It is selected to be larger than ₂₁ .

That is, the two IGBTs 21 and 22 are:
Its maximum rated voltage V ₂₁ , V ₂₂ and maximum rated current I ₂₁ ,
I ₂₂ is selected so as to have the relationship of the following equation (2).

(Equation 2)

[3-2. Operation] According to the present embodiment having the above-described configuration, similarly to the first embodiment, even when an overcurrent or an overvoltage is applied to the control device, the load control ability can be sufficiently maintained. Can be. Hereinafter, this operation will be specifically described.

For example, in the control device of the present embodiment, the current I satisfying I ₂₂ >I> V ₂₁ is applied to each of the IGBTs _{21 and 21.}
2, at least a high withstand current type IGBT2
2 escapes failure. In the control device of the present embodiment, the voltage V satisfying V ₂₁ >V> V _{22 is} applied to each IGBT 21,
22, at least a high withstand voltage type IG
BT21 escapes from failure.

In the present embodiment, the first
As in the embodiment, the failure of the IGBT 21 or 22 can be quickly detected during operation by measuring the voltage between the electrodes, so that a measure such as an alarm display can be taken. Further, the value of the maximum rated voltage V ₂₁ of the high withstand voltage type IGBT ₂₁ is set sufficiently higher than the expected maximum voltage V _max , and the value of the maximum rated current I ₂₂ of the high withstand voltage type IGBT ₂₂ is set to the maximum expected value. by setting sufficiently larger than the current I _max, the possibility of falling into a situation that the DC motor 10 becomes impossible stop can be made very low.

[3-3. Effect] As described above, in general, it is difficult to achieve both a high maximum rated voltage and a large maximum rated current at the same external dimensions of a semiconductor element. However, according to the present embodiment, a small high withstand voltage IG having a large maximum rated voltage and a relatively small maximum rated current.
The BT21 can be used in combination with a small high-current-resistant IGBT22 having a large maximum rated current and a relatively small maximum rated voltage. Therefore, without significantly increasing the size and manufacturing cost of the control device, the excellent withstand voltage performance and current withstand performance of the two types of IGBTs are used synergistically to achieve the control limit voltage characteristics and control limit of the entire control device. Both current characteristics can be improved. Therefore, according to the present embodiment, similarly to the first embodiment, it is possible to maintain the miniaturization and economy of the substation equipment control device, and also to greatly improve the reliability thereof.

[4. Fourth Embodiment] [4-1. Configuration] FIG. 4 is a basic circuit diagram showing one embodiment of a substation control apparatus to which the invention of claim 3 is applied as a fourth embodiment of the present invention. This figure 4
In the figure, reference numeral 31 denotes a heavy protection IGBT which is heavily protected against a surge voltage, and reference numeral 32 denotes a light protection IGBT which is protected relatively lightly than the heavy protection IGBT 31. Here, the heavy protection IGBT 31 is provided with a surge absorbing element 33 having a low limiting voltage, so that the protection capability of the overvoltage protection circuit is high. The light protection IGBT 32 is provided with a surge absorbing element 34 having a voltage limit slightly lower than the maximum rated voltage of the element, and the protection capability of the overvoltage protection circuit is lower than that of the heavy protection IGBT 31. As shown in FIG. 4, a heavy protection IGBT 31 having a surge absorbing element 33, a light protection IGBT 32 having a surge absorbing element 34, and a DC motor 10 are connected in series. Each is connected to the power supply 2.

[4-2. Operation] According to the present embodiment having the above configuration, even when an overvoltage due to a surge is applied to the control device, the load control capability can be sufficiently maintained. Hereinafter, this operation will be specifically described.

First, generally, as shown in FIG. 5, the value of the limiting voltage of the surge absorbing element increases as the value of the current supplied to the surge absorbing element increases. Therefore, if the surge having a larger energy than the designed value V _A of the maximum surge voltage is applied to the control device, as in FIG. 5, the flow overcurrent I _B exceeding the design value I _A of the maximum surge current, I
Overvoltage V _B is generated that exceeds the maximum rated voltage V _C of the GBT, IGBT is sometimes fail.

However, even in such a case, according to the control device of the present embodiment, the possibility of failure can be extremely reduced for the heavy protection IGBT 31 protected by the surge absorbing element 33 having a low limiting voltage. In this embodiment, as in the first embodiment, IG
The failure of BT31 or BT32 is determined by measuring the voltage between contacts.
Since it can be detected quickly during operation, measures such as alarm display can be taken.

[4-3. Effect] In general, a surge absorbing element having a low limiting voltage absorbs a large amount of energy. Therefore, in order to prevent destruction due to heat generation, it is necessary to employ a large element having a large surge absorption resistance. That is, a surge absorbing element having a lower limiting voltage has a considerably larger outer size and a higher price than a surge absorbing element having a higher limiting voltage. From this, a heavy protection IGBT using a surge absorbing element with a low limiting voltage,
Light protection I using surge absorbing element with higher limiting voltage
It is apparent that the present embodiment using one GBT can suppress an increase in the size and manufacturing cost of the control device as compared with a case where two heavy protection IGBTs are connected in series.

Therefore, according to the present embodiment, the size and manufacturing cost of the control device are not increased so much.
In particular, a high load control ability at the time of applying an overvoltage can be secured. In other words, the reliability of the substation control device can be greatly improved while maintaining the miniaturization and economical efficiency.

[5. Fifth Embodiment] [5-1. Configuration] FIG. 6 is a basic circuit diagram showing one embodiment of a substation equipment control apparatus to which the invention of claim 4 is applied as a fifth embodiment of the present invention. This figure 6
, 41 is an IGBT with a large radiator, and 42 is an IGBT with a small radiator. Here, large radiator I
The GBT 41 is provided with a radiator that is sufficiently larger than the size required to prevent the temperature of the IGBT from exceeding the rating in an actual use state. Further, the IGBT 42 with the small radiator is provided with a radiator slightly larger than necessary. As shown in FIG. 6, an IGBT 41 with a large radiator, an IGBT 42 with a small radiator, and the DC motor 10 are connected in series, and both ends thereof are connected to a positive power supply 1 and a negative power supply 2, respectively. .

[5-2. Operation] According to the present embodiment having the above-described configuration, even when an overcurrent or a thermal abnormality is applied to the control device, the load control ability can be sufficiently maintained. Hereinafter, this operation will be specifically described.

For example, in the control device of the present embodiment, even if heat exceeding the estimation is generated in each IGBT and the IGBT 41 with the small radiator is thermally destroyed, at least the IGBT 42 with the large radiator is destroyed. Possibilities can be extremely low. In the present embodiment,
As in the first embodiment, the IGBT 41 or 4
Since the failure of No. 2 can be detected quickly during operation by measuring the voltage between contacts, measures such as alarm display can be taken.

[5-3. Effect] The large radiator has a higher heat radiation capability than the small radiator, but the size is larger and the price is higher. From this, IGB with large radiator
T and one IGBT with a small radiator are used in this embodiment, and two IGBTs with a large radiator are connected in series.
Obviously, an increase in the size and manufacturing cost of the control device can be suppressed as compared with the case where the individual devices are connected.

Therefore, according to the present embodiment, the size and manufacturing cost of the control device are not increased so much.
In particular, high load control capability can be ensured when overcurrent is applied or when a thermal abnormality occurs. In other words, the reliability of the substation control device can be greatly improved while maintaining the miniaturization and economical efficiency.

[6. Other Embodiments] The present invention
The present invention is not limited to the above-described embodiments, and various other embodiments can be implemented, and similarly, excellent operational effects can be obtained. For example, a configuration in which the inventions of claims 1 to 5 are selectively combined and applied is also possible. Further, the semiconductor element is not limited to the IGBT, and the same excellent effect can be obtained by using other various semiconductor elements. In this connection, specific configurations of the overvoltage protection circuit and the radiator associated with the semiconductor element can be freely configured. Further, the load to be controlled is not limited to the DC motor, and similarly excellent effects can be obtained when another load such as a coil is to be controlled.

On the other hand, in each of the above-described embodiments, a configuration in which two semiconductor elements are connected in series to one load to be controlled has been described. However, in the present invention, one load to be controlled is connected to one load to be controlled. On the other hand, it is similarly possible to connect three or more semiconductor elements in series, in which case the reliability of the control device can be further improved. Further, in the second embodiment, the configuration in which the individual semiconductor elements and the single common semiconductor element are connected in series to the two loads to be controlled has been described. A configuration in which an individual semiconductor element and a single common semiconductor element are connected in series to the target load is also possible, and a configuration in which individual semiconductor elements and a plurality of common semiconductor elements are provided is also possible. is there. In any case, the reliability of the control device can be further improved by increasing the number of semiconductor elements connected in series.

[0065]

As described above, according to the present invention,
The use of high-performance, large-scale elements for only some of the multiple semiconductor elements or their accessory elements enables high load control capability when overvoltage is applied or overcurrent is applied without significantly increasing the size and manufacturing cost. It is possible to provide a substation control device which can be secured, is small, has excellent economic efficiency, and has high reliability.

[Brief description of the drawings]

FIG. 1 is a basic circuit diagram showing a substation device control device according to a first embodiment of the present invention.

FIG. 2 is a basic circuit diagram showing a substation device control device according to a second embodiment of the present invention.

FIG. 3 is a basic circuit diagram showing a substation device control device according to a third embodiment of the present invention.

FIG. 4 is a basic circuit diagram showing a substation equipment control device according to a fourth embodiment of the present invention.

FIG. 5 is a graph showing an outline of a relationship between a current flowing through a general surge absorbing element and a limit voltage.

FIG. 6 is a basic circuit diagram showing a substation control device according to a fifth embodiment of the present invention.

FIG. 7 is a basic circuit diagram showing an example of a conventional substation control device.

[Explanation of symbols]

 1: Positive power supply 2: Negative power supply 10, 10a, 10b: DC motor 11, 11a, 11b: Low rated IGBT 12: High rated IGBT 21: High withstand voltage type IGBT 22: High withstand current type IGBT 31: Heavy protection IGBT 32 : Light protection IGBT 33, 34: Surge absorbing element 41: IGBT with large radiator 42: IGBT with small radiator

Claims (5)

[Claims] 1. A substation equipment control device that controls energization of a load to be controlled by connecting a plurality of semiconductor elements in series and simultaneously setting an energization enabled state or an energization blocked state of the plurality of semiconductor elements. A plurality of semiconductor elements include a plurality of types of semiconductor elements having different maximum ratings, and the first type of semiconductor element has a higher maximum rating than the second type of semiconductor elements. 2. A substation control apparatus for controlling the energization of a load to be controlled by connecting a plurality of semiconductor elements in series and simultaneously setting the plurality of semiconductor elements to an energizable state or an energized blocking state, The plurality of semiconductor elements include a plurality of types of semiconductor elements having different maximum rated voltages and maximum rated currents, the first type of semiconductor element has a higher maximum rated voltage than the second type of semiconductor elements, The semiconductor device of the type has a maximum rated current larger than that of the semiconductor device of the first type. 3. A substation control device for controlling the energization of a load to be controlled by connecting a plurality of semiconductor elements in series and simultaneously setting the plurality of semiconductor elements to an energizable state or an energized blocking state, The plurality of semiconductor devices include a plurality of types of semiconductor devices having different protection capabilities of the overvoltage protection circuit, and the first type of semiconductor device has an overvoltage protection circuit having a higher protection capability than the second type of semiconductor device. Characteristic substation equipment controller. 4. A substation control apparatus for controlling the energization of a load to be controlled by connecting a plurality of semiconductor elements in series and simultaneously setting the plurality of semiconductor elements to an energizable state or an energized blocking state, The plurality of semiconductor elements include a plurality of types of semiconductor elements having different heat dissipation capacities of the radiator, and the first type of semiconductor element has a radiator having a higher heat dissipation capacity than the second type of semiconductor element. Substation equipment control device. 5. The load to be controlled is a plurality of loads, wherein the plurality of semiconductor elements include a plurality of individual semiconductor elements connected in series to the plurality of loads, respectively, A single common semiconductor element that is collectively connected in series, wherein the single common semiconductor element is the first type of semiconductor element, and the plurality of individual semiconductor elements are 5. The substation control device according to claim 1, wherein the control device is a second type of semiconductor device.