Variable control circuit

Abstract

To provide a variable control circuit with reduced board size without incurring additional costs. [Solution] A variable control circuit comprising: a first conversion unit for converting power supplied from a power supply unit to a voltage suitable for the user unit and transmitting it to the user unit; a second conversion unit equipped with a gate board; and a control unit, wherein the gate board comprises: a first control circuit unit connected to the control unit and receiving a PWM signal; a second control circuit unit connected to the first conversion unit and transmitting a drive signal; an intermediate circuit unit; a first isolation unit; a second isolation unit; an isolator installed in the first isolation unit that connects the first control circuit unit and the intermediate circuit unit and transmits the received PWM signal to the intermediate circuit unit; a gate driver IC installed in the second isolation unit that connects the intermediate circuit unit and the second control circuit unit and transmits the received drive signal to the second control circuit unit; and an isolated DC-DC converter that supplies power to the intermediate circuit unit.

Description

Technical Field

[0001] The present invention relates to a variable control circuit.

Background Art

[0002] In an electric vehicle or the like, a variable control circuit that converts DC power supplied from an in-vehicle battery into three-phase AC power for driving an in-vehicle motor mounts a control element and a driving element in one package, and there is a demand for improving the withstand voltage between the low power supply voltage on the control element side and the high power supply voltage on the driving element side (see, for example, Patent Document 1). For the insulation of the gate substrate on which the control element and the driving element are mounted, either single-stage enhanced insulation or two-stage basic insulation is required. When the high power supply voltage on the driving element side is less than 1000V, the creepage distance, which is the width of the required single-stage enhanced insulation, is 5mm. For example, according to IEC61800-5-1 (Variable Speed Drive System (Power Drive System, PDS) - Safety Requirements), in a printed circuit board with a pollution degree of 2, when the high power supply voltage on the driving element side is 1000V, if it is single-stage enhanced insulation, a creepage distance of 10mm or more is required, and if it is two-stage basic insulation, a creepage distance of 5mm or more for each is required.

[0003] A gate driver IC is installed between the control element and the driving element. However, currently available commercially available gate driver ICs generally and easily obtainable ones correspond to a creepage distance of 8mm or less. When the high power supply voltage on the driving element side is 1000V or more and the creepage distance is 10mm or more with single-stage enhanced insulation, as shown in FIG. 3, commercially available gate driver ICs cannot be used because they do not correspond to the creepage distance. Since new development of a gate driver IC corresponding to a creepage distance of 10mm or more requires a great deal of cost, it is necessary to use two-stage basic insulation in order to suppress the cost. When each creepage distance is 5mm or more with two-stage basic insulation, as shown in FIG. 4, an intermediate circuit is required between the control element and the driving element, and furthermore, a power supply for supplying power to the intermediate circuit is required, so the substrate becomes larger.

Prior Art Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2024-043151 Specification [Overview of the project] [Problems that the invention aims to solve]

[0005] However, there are size limitations on the package that houses the control and drive elements, which limits the size of the substrate. Furthermore, increasing the size of the substrate results in a control circuit that is specific to the manufacturer and not general-purpose. Patent document 1 also does not disclose any methods for addressing the need for larger substrates.

[0006] In view of the above problems, the present invention aims to provide a variable control circuit that reduces the size of the substrate without incurring additional costs. [Means for solving the problem]

[0007] A first aspect of the present invention is a variable control circuit installed in a housing, comprising: a first conversion unit for converting power supplied from a power supply unit into a voltage suitable for a user unit and transmitting it to the user unit; a second conversion unit connected to the first conversion unit and equipped with a gate board; and a control unit that transmits a PWM signal to the second conversion unit and controls the first conversion unit, wherein the second conversion unit converts the PWM signal into a drive signal for the first conversion unit and transmits it to the first conversion unit, and the gate board of the second conversion unit comprises: a first control circuit unit connected to the control unit and receiving the PWM signal; a second control circuit unit connected to the first conversion unit and transmitting the drive signal; and a first control The gist of the device is that it comprises an intermediate circuit section located between the circuit section and the second control circuit section and at the same potential as the enclosure's ground; a first insulating section located between the first control circuit section and the intermediate circuit section; a second insulating section located between the intermediate circuit section and the second control circuit section; an isolator installed in the first insulating section that connects the first control circuit section and the intermediate circuit section and transmits the received PWM signal to the intermediate circuit section; a gate driver IC installed in the second insulating section that connects the intermediate circuit section and the second control circuit section and transmits the received drive signal to the second control circuit section; and an isolated DC-DC converter that supplies power to the intermediate circuit section.

[0008] In a first embodiment of the present invention, the first conversion unit may be an insulated-gate bipolar transistor.

[0009] In the first embodiment of the present invention, the width of the second insulating portion may be 5 to 8 mm.

[0010] In the first embodiment of the present invention, the output side of the intermediate circuit section and the isolated DC-DC converter may be connected to a ground at the same potential as the enclosure's earth.

[0011] In a first embodiment of the present invention, the power supply unit may be an on-board battery, and the power supply unit may be an on-board drive motor.

[0012] In the first embodiment of the present invention, the voltage of the power supply unit may be 1000V or higher.

[0013] According to the present invention, the device comprises: a first conversion unit for converting power supplied from a power supply unit into a voltage suitable for the user unit and transmitting it to the user unit; a second conversion unit connected to the first conversion unit and equipped with a gate board; and a control unit that transmits a PWM signal to the second conversion unit and controls the first conversion unit. The second conversion unit converts the PWM signal into a drive signal for the first conversion unit and transmits it to the first conversion unit. The gate board of the second conversion unit comprises: a first control circuit unit connected to the control unit and receiving the PWM signal; a second control circuit unit connected to the first conversion unit and transmitting the drive signal; and an intermediate control circuit unit positioned between the first and second control circuit units. The circuit comprises a circuit section, a first insulating section positioned between the first control circuit section and the intermediate circuit section, a second insulating section positioned between the intermediate circuit section and the second control circuit section, an isolator installed in the first insulating section that connects the first control circuit section and the intermediate circuit section and transmits the received PWM signal to the intermediate circuit section, a gate driver IC installed in the second insulating section that connects the intermediate circuit section and the second control circuit section and transmits the received drive signal to the second control circuit section, and an isolated DC-DC converter that supplies power to the intermediate circuit section. Therefore, a variable control circuit can be provided with reduced board size without incurring additional costs. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram illustrating an example of a variable control circuit according to an embodiment of the present invention. [Figure 2] This is a block diagram of the entire system of an example of a variable control circuit according to the embodiment. [Figure 3] This is a schematic diagram illustrating an example of a variable control circuit using a single-stage reinforced insulation according to conventional technology. [Figure 4] This is a schematic diagram illustrating an example of a variable control circuit using a two-stage basic insulation method according to conventional technology. [Modes for carrying out the invention]

[0015] Next, embodiments of the present invention will be described with reference to the drawings. In the description of the drawings according to the embodiments, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationships such as the relationship with the planar dimensions are different from the actual ones. Therefore, specific dimensions should be determined in consideration of the following description. Of course, the drawings also include parts where the dimensional relationships and ratios between the drawings are different from each other.

[0016] Moreover, the embodiments illustrate devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the configuration, arrangement, layout, etc. of each component as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0017] (Embodiment) A schematic diagram of an example of a variable control circuit according to an embodiment of the present invention is shown in FIG. 1. The variable control circuit 10 shown in FIG. 1 includes a first conversion unit 13, a second conversion unit 11, and a control unit 12.

[0018] Also, a block diagram of the entire system of an example of the variable control circuit 10 according to the present embodiment is shown in FIG. 2. The variable control circuit 10 shown in FIG. 2 is connected to a power supply unit 21 and a usage unit 22.

[0019] The first conversion unit 13 converts the power supplied from the power supply unit 21 into a voltage suitable for the usage unit 22 and transmits it to the usage unit 22. As an example, the first conversion unit 13 is an insulated gate bipolar transistor (IGBT).

[0020] The second conversion unit 11 includes a gate substrate 19 and an isolated DCDC converter 17, is connected to the first conversion unit 13, and controls the first conversion unit 13.

[0021] The control unit 12 transmits a Pulse Width Modulation (PWM) signal 121 to the second conversion unit 11. The PWM signal is a signal for controlling a circuit by adjusting the pulse width during the on-time while keeping the pulse magnitude and period constant.

[0022] The second conversion unit 11 converts the PWM signal 121 into a drive signal 161 for the first conversion unit 13 and transmits it to the first conversion unit 13.

[0023] The gate substrate 19 of the second conversion unit 11 includes a first control circuit unit 14, a second control circuit unit 16, an intermediate circuit unit 15, a first insulating unit 141, a second insulating unit 151, an isolator 110, and a gate driver IC 111.

[0024] The first control circuit unit 14 is connected to the control unit 12 and receives the PWM signal 121.

[0025] The second control circuit unit 16 is connected to the first conversion unit 13 and transmits the drive signal 161.

[0026] The intermediate circuit unit 15 is disposed between the first control circuit unit 14 and the second control circuit unit 16.

[0027] The first insulating unit 141 is disposed between the first control circuit unit 14 and the intermediate circuit unit 15.

[0028] The second insulating unit 151 is disposed between the intermediate circuit unit 15 and the second control circuit unit 16.

[0029] The isolator 110 is installed in the first insulating unit 141, connects the first control circuit unit 14 and the intermediate circuit unit 15, and transmits the received PWM signal 121 to the intermediate circuit unit 15.

[0030] The gate driver IC 111 is installed in the second insulating section 151 and connects the intermediate circuit section 15 and the second control circuit section 16. The gate driver IC 111 receives the PWM signal 121, converts it into a drive signal 161, and transmits it to the second control circuit section 16. As for the gate driver IC 111, in the variable control circuit according to this embodiment, a commercially available general-purpose IC may be used instead of developing a unique one from scratch. A general-purpose gate driver IC has two connectable circuits, and in this embodiment, the distance between the two circuits, the intermediate circuit section 15 and the second control circuit section 16, i.e., the creepage distance of the second insulating section 151 is 8 mm or less.

[0031] When the voltage of the first conversion unit 13 is 1000V or higher, a creepage distance of 10mm or more is required for insulation between the first control circuit unit 14 and the second control circuit unit 16 if reinforced insulation is used in one stage, or a creepage distance of 5mm or more is required for each of the two stages of basic insulation. Since the creepage distance of a general-purpose gate driver IC is 8mm or less, if a general-purpose gate driver IC is used as the gate driver IC 111, and reinforced insulation is used in one stage for insulation between the first control circuit unit 14 and the second control circuit unit 16, the creepage distance of a general-purpose gate driver IC will be insufficient, and it will be necessary to develop a new gate driver IC with a creepage distance of 10mm or more. However, due to cost and versatility issues, it is difficult to develop a new gate driver IC with a creepage distance of 10mm or more.

[0032] Therefore, in this embodiment, a two-stage basic insulation is employed as insulation between the first control circuit section 14 and the second control circuit section 16, thereby providing an intermediate circuit section 15 between the first control circuit section 14 and the second control circuit section 16. If the creepage distance between the intermediate circuit section 15 and the second control circuit section 16, i.e., the second insulation section 151, is set to 5 to 8 mm, a general-purpose gate driver IC can be used as the gate driver IC 111.

[0033] The isolated DC-DC converter 17 supplies power to the intermediate circuit section 15. The DC-DC converter is an element that performs voltage conversion using a transformer, and the input and output sides are isolated by the transformer. The isolated DC-DC converter 17 supplies power to the gate driver IC 111. Both the isolator 110 and the gate driver IC 111 require power supplies on their respective input and output sides. The input side of the isolator 110 receives power from the control unit 12, and the output side receives power from the isolated DC-DC converter 17. The input side of the gate driver IC 111 receives power from the isolated DC-DC converter 17, and the output side receives power from a power supply created by further isolating the power supply of the isolated DC-DC converter 17 from the intermediate circuit section 15. The isolated DC-DC converter 17 takes the power supply (not shown) that supplies power to the control unit 12 as its input, and the intermediate circuit section 15 as its output.

[0034] If the isolated DC-DC converter 17 is installed on the gate board 19, the gate board 19 becomes very large. As shown in Figure 1, by installing the isolated DC-DC converter 17 outside the gate board 19 instead of on it, space can be saved.

[0035] The input ground of the isolated DC-DC converter 17 is common with the ground of the first control circuit unit 14. The output ground of the isolated DC-DC converter 17 is connected to the intermediate circuit unit 15 and simultaneously to the housing 112 of the variable control circuit unit 10. By setting the output ground of the isolated DC-DC converter 17 to the same potential as the grounds of the intermediate circuit unit 15 and the housing 112, the intermediate circuit unit 15 does not require a voltage withstand voltage. The second control circuit unit 16 requires a voltage withstand voltage of 1.5kV to ground, but by setting the grounds of the isolated DC-DC converter 17, the intermediate circuit unit 15, and the housing 112 to the same potential, the second control circuit unit 16 does not require a voltage withstand voltage of 1.5kV to ground.

[0036] When the variable control circuit 10 according to this embodiment is applied to, for example, an electric vehicle, the housing of the variable control circuit 10 is the body of the electric vehicle.

[0037] For example, the power supply unit 21 is an on-board battery, and the operating unit 22 is an on-board drive motor.

[0038] (Comparative Example 1) The variable control circuit 10 according to the above embodiment has an intermediate circuit section 15 between the first control circuit section 14 and the second control circuit section 16, and employs two stages of basic insulation for insulation between the first control circuit section 14 and the second control circuit section 16. In this comparative example 1, the case in which there is no intermediate circuit section 15 between the first control circuit section 14 and the second control circuit section 16, and the insulation between the first control circuit section 14 and the second control circuit section 16 is one stage of reinforced insulation will be explained with reference to Figure 3.

[0039] The variable control circuit 31 shown in Figure 3 has an insulating section 33, which is a reinforced insulation stage, between the first control circuit section 14 and the second control circuit section 16. If the high power supply voltage of the first conversion section is less than 1000V, the creepage distance of the insulating section 33 is 5mm, and a commercially available gate driver IC capable of handling a creepage distance of up to 8mm can be used as the gate driver IC 111.

[0040] However, when the high power supply voltage of the first conversion unit is 1000V or higher, the surface distance of the reinforced insulation of one stage is 10mm, so as shown in Figure 3, commercially available gate driver ICs cannot connect the first control circuit unit 14 and the second control circuit unit 16.

[0041] (Comparative Example 2) In this comparative example 2, an intermediate circuit section 15 is provided between the first control circuit section 14 and the second control circuit section 16. The case in which the isolated DC-DC converter 17 is installed on the gate substrate 19 will be explained with reference to Figure 4.

[0042] In this Comparative Example 2, since an intermediate circuit section 15 is provided between the first control circuit section 14 and the second control circuit section 16, unlike in Comparative Example 3, even when the high power supply voltage of the first conversion section is 1000V or higher, a commercially available gate driver IC capable of handling creepage distances up to 8mm can be used as the gate driver IC 111.

[0043] In the variable control circuit 10 according to the above embodiment, the isolated DC-DC converter 17 that supplies power to the gate driver IC 111 was installed outside the gate substrate 19. In contrast, in this comparative example 2, the isolated DC-DC converter 42 that supplies power to the gate driver IC 111 is installed on the gate substrate 19.

[0044] As shown in Figure 4, if the isolated DC-DC converter 17 is mounted on the gate substrate 19, the gate substrate 19 becomes very large, making it difficult to house it within the package that mounts the control element and the drive element.

[0045] As described above, the variable control circuit according to this embodiment uses two stages of basic isolation and installs the isolated DC-DC converter supplying power to the gate driver IC outside the gate board, making it possible to provide a variable control circuit that can handle high voltages of 1000V or more without incurring additional costs and while keeping the board size small.

[0046] As stated above, the present invention naturally includes various embodiments and the like that are not described herein. Therefore, the technical scope of the present invention is determined solely by the inventive features relating to the claims that are reasonable based on the above description. [Explanation of symbols]

[0047] 10, 31, 41 Variable control circuit 11 Second Conversion Section 12 Control Unit 13. First Conversion Unit 14. First Control Circuit Section 15 Intermediate circuit section 16. Second Control Circuit Section 17, 42 Isolated DC-DC Converters 19, 32 gate substrate 110 Isolator 111 Gate Driver IC 112, 34 cabinets 121 PWМ signal 141 First insulating section 151 Second insulating section 161 Drive signal 171, 172 connectors 21 Power supply section 22 Used part 33 Insulation part

Claims

1. A first conversion unit for converting the power supplied from the power supply unit into a voltage suitable for the user unit and transmitting it to the user unit, A second conversion unit, connected to the first conversion unit and equipped with a gate board, The system includes a control unit that transmits a PWM signal to the second conversion unit to control the first conversion unit, the second conversion unit converts the PWM signal into a drive signal for the first conversion unit and transmits it to the first conversion unit, The gate substrate of the second conversion unit is A first control circuit unit connected to the control unit and receiving the PWM signal, A second control circuit unit that connects to the first conversion unit and transmits the drive signal, An intermediate circuit section is arranged between the first control circuit section and the second control circuit section and is at the same potential as the ground of the housing, A first insulating section is disposed between the first control circuit section and the intermediate circuit section, A second insulating section is disposed between the intermediate circuit section and the second control circuit section, An isolator installed in the first insulating section, connecting the first control circuit section and the intermediate circuit section, and transmitting the received PWM signal to the intermediate circuit section, A gate driver IC is installed in the second insulating section, connects the intermediate circuit section and the second control circuit section, and transmits the received drive signal to the second control circuit section. The system includes an isolated DC-DC converter that supplies power to the intermediate circuit section. A variable control circuit installed within the aforementioned housing, characterized by the above.

2. The variable control circuit according to claim 1, wherein the first conversion unit is an insulated gate bipolar transistor.

3. The variable control circuit according to claim 1, wherein the width of the second insulating portion is 5 to 8 mm.

4. The variable control circuit according to claim 1, wherein the output side of the intermediate circuit section and the isolated DC-DC converter are connected to a ground at the same potential as the ground of the housing.

5. The variable control circuit according to claim 1, wherein the power supply unit is an on-board battery and the usage unit is an on-board drive motor.

6. The variable control circuit according to claim 2, characterized in that the voltage of the power supply unit is 1000V or more.

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