JP7014635B2 - Inverter unit and motor assembly - Google Patents

Description

The present invention relates to an inverter unit and an electric motor assembly including the inverter unit.

Inverters that control the rotational speed of motors are known. The inverter is composed of many elements such as a power element (for example, an IGBT: Insulated gate bipolar transistor) and an electrolytic capacitor.

Japanese Unexamined Patent Publication No. 2016-9838 Japanese Unexamined Patent Publication No. 2016-19401 Japanese Unexamined Patent Publication No. 9-84302

Since the power element that operates when driving the inverter of the motor and the electrolytic capacitor that operates together with the power element are heat sources, the temperature of the power element and the temperature of the electrolytic capacitor become high when the inverter is driven. Generally, the so-called Arrhenius law, which doubles the life of an electrolytic capacitor when the temperature of the electrolytic capacitor drops by 10 ° C. (10 ° C. double rule), is applied to the electrolytic capacitor. Therefore, if the temperature of the electrolytic capacitor is lowered, the life of the electrolytic capacitor is expected to be long.

Therefore, an object of the present invention is to provide an inverter unit capable of extending the life of an electrolytic capacitor. It is an object of the present invention to provide a motor assembly equipped with the inverter unit.

One aspect is arranged between an inverter element including an electrolytic capacitor, a board on which the inverter element is mounted, an inverter mounting member to which the board is mounted, and an inner surface of the electrolytic capacitor and the inverter mounting member. A thermoelectric conversion element, a power supply device electrically connected to the thermoelectric conversion element to supply electric power to the thermoelectric conversion element, and a control device electrically connected to the power supply device to control the operation of the power supply device. The thermoelectric conversion element has one surface in contact with the electrolytic capacitor and the opposite surface located on the opposite side of the one surface and in contact with the inner surface of the inverter mounting member. The control device is an inverter unit characterized in that electric power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the inverter mounting member.

In a preferred embodiment, the inverter unit includes a temperature sensor arranged adjacent to the electrolytic capacitor, the control device monitors the temperature detected by the temperature sensor, and the temperature starts to cool. When the temperature rises to the value, the power supply device supplies electric power to the thermoelectric conversion element, and the heat of the electrolytic capacitor is transferred to the inverter mounting member.
In a preferred embodiment, the inverter unit transfers the direction of the current flowing through the thermoelectric conversion element to the electrolytic capacitor, the first current direction for transmitting the heat of the electrolytic capacitor to the inverter mounting member, and the heat of the inverter mounting member to the electrolytic capacitor. A switch unit for switching between the current direction and the second current direction is provided, and when the temperature rises to the cooling start threshold value, the control device operates the switch unit and flows to the thermoelectric conversion element. When the direction of the current is switched to the first current direction and the temperature is equal to or less than the heating start threshold value smaller than the cooling start threshold value, the switch unit is operated to obtain the current flowing through the thermoelectric conversion element. It is characterized in that the direction is switched to the second current direction.
In a preferred embodiment, the substrate is arranged parallel to the inner surface of the inverter mounting member and has an insertion hole having a size into which the electrolytic capacitor can be inserted, and the electrolytic capacitor is the electrolytic capacitor. The bottom surface of the capacitor is inserted into the insertion hole so as to face the inner surface of the inverter mounting member via the thermoelectric conversion element.

Another aspect is to contact the inverter element including the electrolytic capacitor, the substrate on which the inverter element is mounted, the inverter mounting member to which the substrate is mounted, and the inner surface of the inverter mounting member to accommodate the electrolytic capacitor. A capacitor case, a thermoelectric conversion element attached to the inner surface of the capacitor case, a power supply device electrically connected to the thermoelectric conversion element to supply power to the thermoelectric conversion element, and electrically to the power supply device. It comprises a control device that is connected and controls the operation of the power supply device, the thermoelectric conversion element is located on one surface in contact with the electrolytic capacitor and on the opposite side of the one surface, and is an inner surface of the capacitor case. The control device has a surface on the opposite side in contact with the capacitor, and the control device is characterized in that power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the capacitor case. It is an inverter unit.

In a preferred embodiment, the inverter unit includes a temperature sensor arranged adjacent to the condenser case, the control device monitors the temperature detected by the temperature sensor, and the temperature starts to cool. When the temperature rises to a value, the power supply device supplies power to the thermoelectric conversion element, and the heat of the electrolytic capacitor is transferred to the capacitor case.
In a preferred embodiment, the inverter unit has a first current direction for transferring the direction of the current flowing through the thermoelectric conversion element to the capacitor case and a first current direction for transferring the heat of the capacitor case to the electrolytic capacitor. A switch unit for switching between two current directions is provided, and the control device operates the switch unit when the temperature rises to the cooling start threshold value, and the current flowing through the thermoelectric conversion element. When the direction is switched to the first current direction and the temperature is equal to or less than the heating start threshold value smaller than the cooling start threshold value, the switch unit is operated to change the direction of the current flowing through the thermoelectric conversion element. It is characterized by switching in the second current direction.
In a preferred embodiment, the substrate is arranged parallel to the inner surface of the inverter mounting member and has an insertion hole having a size into which the capacitor case can be inserted, and the capacitor case is the electrolytic capacitor. The bottom surface of the inverter is inserted into the insertion hole so as to face the inner surface of the inverter mounting member via the capacitor case.

Yet another embodiment includes a drive shaft, a motor including a rotor and a stator for rotating the drive shaft, a motor casing accommodating the motor, and an inverter unit for controlling the rotation speed of the motor. The inverter unit includes an inverter element including an electrolytic capacitor, a board on which the inverter element is mounted, an inverter mounting member that closes the open end of an inverter frame connected to the motor casing, and to which the board is mounted. The thermoelectric conversion element arranged between the electrolytic capacitor and the inner surface of the inverter mounting member, the power supply device electrically connected to the thermoelectric conversion element and supplying power to the thermoelectric conversion element, and the power supply device. It is electrically connected and includes a control device that controls the operation of the power supply device, and the thermoelectric conversion element is located on one surface in contact with the electrolytic capacitor and on the opposite side of the one surface. It has a surface on the opposite side that contacts the inner surface of the inverter mounting member, and the control device supplies power from the power supply device to the thermoelectric conversion element and transfers the heat of the electrolytic capacitor to the inverter mounting member. It is an electric motor assembly characterized by being transmitted to an inverter.

Yet another embodiment includes a drive shaft, a motor including a rotor and a stator for rotating the drive shaft, a motor casing accommodating the motor, and an inverter unit for controlling the rotation speed of the motor. The inverter unit includes an inverter element including an electrolytic capacitor, a board on which the inverter element is mounted, an inverter mounting member that closes the open end of an inverter frame connected to the motor casing, and to which the board is mounted. A capacitor case that comes into contact with the inner surface of the inverter mounting member and accommodates the electrolytic capacitor, a thermoelectric conversion element attached to the inner surface of the capacitor case, and the thermoelectric conversion element that is electrically connected to the thermoelectric conversion element. The thermoelectric conversion element includes a power supply device that supplies power to the power supply device and a control device that is electrically connected to the power supply device and controls the operation of the power supply device. And, which is located on the opposite side of the one surface and has the opposite surface in contact with the inner surface of the condenser case, the control device causes the power supply device to supply power to the thermoelectric conversion element. The electric motor assembly is characterized in that the heat of the electrolytic capacitor is transferred to the capacitor case.

The control device supplies electric power from the power supply device to the thermoelectric conversion element, and transfers the heat of the electrolytic capacitor to the inverter mounting member. In this way, the control device can cool the electrolytic capacitor via the thermoelectric conversion element, so that the life of the electrolytic capacitor can be extended according to the Arrhenius law.

It is a figure which shows one Embodiment of an inverter unit. It is an enlarged view of an electrolytic capacitor and a thermoelectric conversion element. FIG. 3A is a view seen from the direction of line A in FIG. 2 (state in which the electrolytic capacitor is not arranged), and FIG. 3B is a view seen from the direction of line A in FIG. 2 (electrolytic capacitor is arranged). It is in the state of being done). It is a figure which shows one Embodiment of the control system of the inverter unit including the control device. It is a figure which shows the processing flow of a control device. It is a figure which shows the switch part. It is a figure for demonstrating the direction of the current flowing through a thermoelectric conversion element. It is a figure for demonstrating the direction of the current flowing through a thermoelectric conversion element. It is a figure which shows the processing flow of a control device. It is a figure which shows the other embodiment of the inverter unit. It is a figure which shows how the electrolytic capacitor is housed in a capacitor case. It is a figure which shows the electric motor assembly which provided with the inverter unit.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are designated by the same reference numerals and duplicated description will be omitted. In the plurality of embodiments described below, the configuration of one embodiment not particularly described is the same as that of the other embodiments, and therefore the duplicated description thereof will be omitted.

FIG. 1 is a diagram showing an embodiment of the inverter unit 3. The inverter unit 3 can be applied to a photovoltaic power generation system using a solar panel, or a mechanical device such as an electric motor assembly for rotating a rotating machine such as a pump. In the embodiment described later, the structure of the motor assembly 1 including the inverter unit 3 will be described.

As shown in FIG. 1, the inverter unit 3 is equipped with an inverter element 41 including an electrolytic capacitor 41A that smoothes electric power rectified by a rectifier (not shown) and stores charge by capacitance, and an inverter element 41. A board 42 and an inverter mounting member 23 adjacent to the board 42 are provided. In addition to the electrolytic capacitor 41A, the inverter element 41 includes electronic components such as a power element 41B such as an IGBT and a driver circuit (not shown) for driving the power element 41B. The inverter element 41 and the substrate 42 constitute the inverter 20. Hereinafter, the inverter element 41 and the substrate 42 may be collectively referred to as an inverter 20. The inverter 20 is a component necessary for operating the mechanical device to which the inverter unit 3 is applied. Although a single electrolytic capacitor 41A and a single power element 41B are drawn in FIG. 1, the inverter unit 3 may include a plurality of electrolytic capacitors 41A and a plurality of power elements 41B.

The board 42 is attached to the inverter mounting member 23. The inverter 20 is mounted on the inverter mounting member 23, and the substrate 42 is arranged parallel to the inner surface 23a of the inverter mounting member 23. The inverter mounting member 23 has an outer surface 23b located on the side opposite to the inner surface 23a thereof, and a plurality of fins 36 are formed on the outer surface 23b of the inverter mounting member 23. These fins 36 extend outward from the outer surface 23b of the inverter mounting member 23.

The shape of the inverter mounting member 23 is not limited to the embodiment shown in FIG. The shape of the inverter mounting member 23 may be changed according to the structure of the mechanical device to which the inverter unit 3 is applied.

Since the inverter mounting member 23 (and the fin 36) serves as a heat sink, it is basically composed of a material having relatively high heat dissipation performance (for example, a metal having excellent thermal conductivity such as aluminum (Al)). Has been done. The board 42 has a mounting surface 42a on which the inverter element 41 is mounted, and a back surface 42b located on the opposite side of the mounting surface 42a. The power element 41B is arranged on the back surface 42b side of the substrate 42, that is, between the substrate 42 and the inner surface 23a of the inverter mounting member 23.

The power element 41B needs to be used under the condition of the junction temperature (for example, 150 ° C.) or less as the absolute maximum rated temperature. In the present embodiment, the power element 41B, which is a heat generation source, is in contact with the inner surface 23a of the inverter mounting member 23, and the inverter mounting member 23 as a heat sink has a sufficient size to absorb the heat of the power element 41B. is doing. Therefore, the heat generated from the power element 41B is released to the outside through the inverter mounting member 23 and the fins 36, and as a result, the power element 41B is cooled. Therefore, the power element 41B is used under the condition of the junction temperature or lower.

The electrolytic capacitor 41A is also a heat generation source like the power element 41B, and the electrolytic capacitor 41A generates heat due to the influence of the ripple current and the loss due to the equivalent series resistance. As described above, the law that the life of the electrolytic capacitor 41A is doubled (so-called Arrhenius law) is applied to the electrolytic capacitor 41A when the temperature of the electrolytic capacitor 41A drops by 10 ° C. Therefore, if the temperature of the electrolytic capacitor 41A is lowered, the long life of the electrolytic capacitor 41A is realized. Hereinafter, the configuration of the inverter unit 3 capable of extending the life of the electrolytic capacitor 41A will be described.

The inverter unit 3 is a power source that is electrically connected to the thermoelectric conversion element 50 arranged between the electrolytic capacitor 41A and the inner surface 23a of the inverter mounting member 23 and the thermoelectric conversion element 50 to supply electric power to the thermoelectric conversion element 50. It includes a device 51 and a control device 55 that is electrically connected to the power supply device 51 and controls the operation of the power supply device 51.

FIG. 2 is an enlarged view of the electrolytic capacitor 41A and the thermoelectric conversion element 50. As shown in FIG. 2, the thermoelectric conversion element 50 is located on one surface (contact surface on the electrolytic capacitor side) 50a in contact with the electrolytic capacitor 41A and on the opposite side of the one surface 50a, and is located on the inner surface 23a of the inverter mounting member 23. It has a surface on the opposite side (contact surface on the inverter mounting member side) 50b that comes into contact with the capacitor.

The thermoelectric conversion element 50 is a known perche element that exerts a perche effect by the electric power supplied from the power supply device 51, and has a plate-like structure in which P-type semiconductors and N-type semiconductors are alternately arranged. The thermoelectric conversion element 50 has a structure in which a heat flow is generated between both surfaces of the thermoelectric conversion element 50 (that is, one surface 50a and the opposite surface 50b) by the electric power supplied from the power supply device 51.

In one embodiment, the thermoelectric conversion element 50 may have a structure that converts a spin current generated by electric power supplied from the power supply device 51 into a heat flow. The thermoelectric conversion element 50 having such a structure is an element using a spin conversion technique, and is a tape-shaped thermoelectric conversion element having a thin film shape described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-9838). It has a similar thermoelectric conversion structure.

Spin conversion is a general term for mutual conversion of physical quantities (for example, heat, electricity, etc.) based on the law of conservation of angular momentum. Spin current is the flow of electron spin angular momentum. There is an interaction between the current, the spin current, and the heat current. Therefore, when electric power is supplied to the thermoelectric conversion element 50, that is, when a current flows, a spin current is generated in the thermoelectric conversion element 50. Such a phenomenon is called a spin Hall effect. When a spin current flows through the thermoelectric conversion element 50, a heat flow is generated in the thermoelectric conversion element 50. Such a phenomenon is called a spin Peltier effect.

Contrary to the spin Pelche effect, when a heat flow flows through the thermoelectric conversion element 50, a spin flow is generated in the thermoelectric conversion element 50. Such a phenomenon is called a spin Seebeck effect. Contrary to the spin Hall effect, when a spin current flows through the thermoelectric conversion element 50, an electromotive force is generated in the thermoelectric conversion element 50. Such a phenomenon is called the reverse spin Hall effect. The thermoelectric conversion element 50 in the present embodiment can convert electric power into a heat flow via spin by utilizing the spin Hall effect and the spin Pelche effect.

As shown in FIG. 2, the electrolytic capacitor 41A includes a main body 60 in which a capacitor element (not shown) is housed therein, and two terminals 61 connected to one end of the main body 60. Each of the two lead wires 62 is connected to each of the two terminals 61, and these lead wires 62 are connected to the mounting surface 42a of the substrate 42. In the present embodiment, the electrolytic capacitor 41A and the substrate 42 are mounted on the inverter mounting member 23, and the terminal 61 is located immediately above the mounting surface 42a of the substrate 42. Therefore, the distance between the terminal 61 and the mounting surface 42a of the substrate 42 is relatively short. With such a configuration, the length of the lead wire 62 connecting the terminal 61 and the mounting surface 42a of the substrate 42 can be made relatively short.

The main body 60 has a terminal surface 60a to which the terminal 61 is connected, a bottom surface 60b located on the opposite side of the terminal surface 60a, and an outer peripheral surface 60c extending between the terminal surface 60a and the bottom surface 60b. One surface 50a (contact surface on the electrolytic capacitor side) of the thermoelectric conversion element 50 is in contact with the bottom surface 60b of the main body 60 of the electrolytic capacitor 41A.

FIG. 3A is a view seen from the direction of line A in FIG. 2 (state in which the electrolytic capacitor is not arranged), and FIG. 3B is a view seen from the direction of line A in FIG. 2 (electrolytic capacitor is arranged). It is in the state of being done). In the present embodiment, the main body 60 of the electrolytic capacitor 41A has a cylindrical shape, and the size of the thermoelectric conversion element 50 in the width direction (more specifically, the diameter of the thermoelectric conversion element 50) is that of the electrolytic capacitor 41A. It is the same as the size of the main body 60 in the width direction (more specifically, the diameter of the outer peripheral surface 60c). The width direction of the thermoelectric conversion element 50 means a direction perpendicular to the thickness direction of the thermoelectric conversion element 50. The width direction of the main body 60 means a direction perpendicular to the height direction of the main body 60. As described above, in the present embodiment, the thermoelectric conversion element 50 has a shape that matches the outer shape of the electrolytic capacitor 41A.

As shown in FIG. 2, the electrolytic capacitor 41A is arranged so that the bottom surface 60b of the main body 60 faces the inner surface 23a of the inverter mounting member 23 via the thermoelectric conversion element 50. In other words, the electrolytic capacitor 41A is mounted on the inverter mounting member 23 via the thermoelectric conversion element 50. Therefore, the thermoelectric conversion element 50 comes into contact with both the bottom surface 60b of the electrolytic capacitor 41A and the inner surface 23a of the inverter mounting member 23.

As shown in FIGS. 2 and 3 (FIGS. 3A and 3B), the substrate 42 has an insertion hole 42c having a size into which the electrolytic capacitor 41A can be inserted, and the insertion hole 42c. Is larger than the diameter of the outer peripheral surface 60c of the main body 60 of the electrolytic capacitor 41A. In FIG. 3, the size of the insertion hole 42c is exaggerated. The insertion hole 42c is a through hole that opens on both the mounting surface 42a and the back surface 42b of the substrate 42. The number of insertion holes 42c corresponds to the number of electrolytic capacitors 41A, and in the present embodiment, a single insertion hole 42c is provided for a single electrolytic capacitor 41A. In one embodiment, instead of providing the insertion hole 42c, a notch extending inward from the outer peripheral surface of the substrate 42 may be provided. The outer peripheral surface of the substrate 42 is the outermost surface of the substrate 42 extending between the mounting surface 42a and the back surface 42b of the substrate 42.

In the present embodiment, the electrolytic capacitor 41A is inserted into the insertion hole 42c so that the bottom surface 60b of the electrolytic capacitor 41A faces the inner surface 23a of the inverter mounting member 23. By inserting the electrolytic capacitor 41A into the insertion hole 42c, the electrolytic capacitor 41A can maintain an upright posture. The electrolytic capacitor 41A may be fixed to the inner surface 23a of the inverter mounting member 23 by using an electrolytic capacitor fixing band (not shown) attached to the outer peripheral surface 60c of the electrolytic capacitor 41A.

When the inverter mounting member 23 has a sufficient size for cooling the entire inverter element 41 including the electrolytic capacitor 41A and the power element 41B, the size of the inverter mounting member 23 is applied to the inverter unit 3. It affects the overall size of the mechanical device. That is, since the overall size of the mechanical device may be determined according to the size of the inverter mounting member 23, if the size of the inverter mounting member 23 is increased, the overall size of the mechanical device also increases. It ends up.

In the present embodiment, the thermoelectric conversion element 50 is interposed between the electrolytic capacitor 41A and the inverter mounting member 23, and is arranged in the gap between the inverter mounting member 23 and the substrate 42. The power supply device 51 supplies electric power to the thermoelectric conversion element 50 based on the command of the control device 55, and the thermoelectric conversion element 50 transfers the heat of the electrolytic capacitor 41A to the inverter mounting member 23 by the Perche effect. As a result, the electrolytic capacitor 41A is cooled.

According to the present embodiment, the thermoelectric conversion element 50 can positively dissipate heat of the electrolytic capacitor 41A to the inverter mounting member 23 due to its Perche effect, so that the size of the inverter mounting member 23 cools the power element 41B. Therefore, it is suppressed to a sufficient size. Since the heat dissipation of the electrolytic capacitor 41A is performed by the thermoelectric conversion element 50, the space saving of the inverter unit 3 is realized.

Since the control device 55 can cool the electrolytic capacitor 41A via the thermoelectric conversion element 50, the life of the electrolytic capacitor 41A can be extended according to the Arrhenius law. If the life of the electrolytic capacitor 41A is extended, the frequency of maintenance of the inverter unit 3 can be reduced, and maintenance-free of the inverter unit 3 can be realized. Further, by extending the life of the electrolytic capacitor 41A, it is possible to reduce the cost required for replacing the electrolytic capacitor 41A.

As shown in FIG. 1, the inverter unit 3 may further include a temperature sensor 70 that detects the temperature of the electrolytic capacitor 41A. In the embodiment shown in FIG. 1, the temperature sensor 70 is arranged on the mounting surface 42a of the substrate 42, but may be directly mounted on the electrolytic capacitor 41A. The temperature sensor 70 arranged adjacent to the electrolytic capacitor 41A is electrically connected to the control device 55, and the temperature detected by the temperature sensor 70 is sent to the control device 55.

FIG. 4 is a diagram showing an embodiment of a control system of the inverter unit 3 including the control device 55. As shown in FIG. 4, the control device 55 includes a monitoring unit 30 that monitors the temperature detected by the temperature sensor 70, that is, the temperature of the electrolytic capacitor 41A (more specifically, the temperature around the electrolytic capacitor 41A). A determination unit 31 is provided, which compares the temperature with a predetermined threshold value (cooling start threshold value) and determines whether or not the temperature has risen to the cooling start threshold value.

The cooling start threshold value is a value of the temperature at which cooling of the electrolytic capacitor 41A should be started, and is stored in a storage unit (not shown) of the control device 55. In one embodiment, the cooling start threshold is best realized by extending the life of the electrolytic capacitor 41A based on Arrhenius's law (correlation between the temperature of the electrolytic capacitor 41A and the estimated life of the electrolytic capacitor 41A). It may be determined to a value that can be expected. For example, the cooling start threshold value may be 40 [° C.].

The control device 55 operates an operation control unit 32 that operates the power supply device 51 to supply electric power from the power supply device 51 to the thermoelectric conversion element 50 when the temperature of the electrolytic capacitor 41A rises to the cooling start threshold value. Further prepared. As shown in FIG. 4, the monitoring unit 30 is connected to the determination unit 31, and the determination unit 31 is connected to the operation control unit 32.

In the present embodiment, since the inverter unit 3 includes the temperature sensor 70, the control device 55 can control the operation of the power supply device 51 based on the temperature detected by the temperature sensor 70. The control device 55 operates according to a program electrically stored (stored) in a storage unit (not shown).

FIG. 5 is a diagram showing a processing flow of the control device 55. As shown in FIG. 5, the monitoring unit 30 of the control device 55 monitors the temperature of the electrolytic capacitor 41A based on the temperature detected by the temperature sensor 70 (see step S101 in FIG. 5). The determination unit 31 of the control device 55 compares this temperature with the cooling start threshold value stored in the storage unit of the control device 55 (see step S102 in FIG. 5), and the temperature of the electrolytic capacitor 41A is the cooling start threshold. When the temperature rises to the value (see “YES” in step S102 in FIG. 5), a signal indicating the result is sent to the operation control unit 32. When the temperature of the electrolytic capacitor 41A has not reached the cooling start threshold value (see “NO” in step S102 in FIG. 5), the monitoring unit 30 continues to monitor the temperature of the electrolytic capacitor 41A.

Upon receiving the signal from the determination unit 31 (the signal indicating that the temperature of the electrolytic capacitor 41A has risen to the cooling start threshold value), the operation control unit 32 operates the power supply device 51 to perform thermoelectric conversion from the power supply device 51. The supply of electric power to the element 50 is started (see step S103 in FIG. 5). By supplying electric power from the power supply device 51 to the thermoelectric conversion element 50, a heat flow is generated on both sides of the thermoelectric conversion element 50 (that is, one surface 50a and the opposite surface 50b), and the heat of the electrolytic capacitor 41A is thermoelectric conversion. It is transmitted to the inverter mounting member 23 as a heat sink via the element 50. The heat transferred to the inverter mounting member 23 is released to the outside through the outer surface 23b and the fin 36 of the inverter mounting member 23, and as a result, the electrolytic capacitor 41A is cooled. Since the control device 55 can control the temperature of the electrolytic capacitor 41A so that the temperature of the electrolytic capacitor 41A does not exceed the allowable temperature, the electrolytic capacitor 41A is used at the temperature at which its life is most expected.

The storage unit of the control device 55 may store a power supply stop threshold value for stopping the supply of electric power from the power supply device 51 to the thermoelectric conversion element 50. The power supply stop threshold value is smaller than the cooling start threshold value and may be arbitrarily determined. The power supply stop threshold value is, for example, 10 [° C.].

When the power supply stop threshold value is provided, as shown in step S104 of FIG. 5, the determination unit 31 compares the temperature of the electrolytic capacitor 41A detected by the temperature sensor 70 with the power supply stop threshold value. When the temperature of the electrolytic capacitor 41A drops to the power supply stop threshold value (see “YES” in step S104 of FIG. 5), the determination unit 31 sends a signal indicating the result to the operation control unit 32. When the temperature of the electrolytic capacitor 41A has not dropped to the power supply stop threshold value (see “NO” in step S104 of FIG. 5), the monitoring unit 30 continues to monitor the temperature of the electrolytic capacitor 41A.

Upon receiving the signal from the determination unit 31, the operation control unit 32 operates the power supply device 51 to stop the supply of electric power from the power supply device 51 to the thermoelectric conversion element 50 (see step S105 in FIG. 5). Due to the suspension of power supply from the power supply device 51 to the thermoelectric conversion element 50, the heat of the electrolytic capacitor 41A is not transferred to the inverter mounting member 23, and as a result, the temperature of the electrolytic capacitor 41A gradually rises. The monitoring unit 30 starts monitoring the temperature of the electrolytic capacitor 41A at the time of starting the inverter unit 3 or immediately after starting the inverter unit 3. The monitoring of the temperature of the electrolytic capacitor 41A by the monitoring unit 30 is continued while the inverter unit 3 is being driven. Therefore, when the temperature of the electrolytic capacitor 41A rises to the cooling start threshold value again, the control device 55 executes the same operation as in step S103 of FIG.

As shown in FIGS. 1 and 4, in the inverter unit 3, the direction of the current flowing through the thermoelectric conversion element 50 is the first current direction in which the heat of the electrolytic capacitor 41A is transferred to the inverter mounting member 23 and the heat of the inverter mounting member 23. May further be provided with a switch unit 56 for switching between the current direction and the second current direction transmitted to the electrolytic capacitor 41A.

FIG. 6 is a diagram showing a switch unit 56. As shown in FIG. 6, the control device 55 is electrically connected to both the power supply device 51 and the switch unit 56, and the operation of the power supply device 51 and the operation of the switch unit 56 can be independently controlled. .. The switch unit 56 includes two switches 65. One of these switches 65 is connected to the anode side of the power supply device 51 by a power supply connection line 66, and the other of the switches 65 is connected to the cathode side of the power supply device 51 by a power supply connection line 66.

The switch unit 56 and the thermoelectric conversion element 50 are connected to each other by two element connection lines 67. More specifically, one end of each element connection line 67 is connected to the thermoelectric conversion element 50, and the other end can be connected to each power supply connection line 66 via each switch 65. Each of the two branch lines 68 is connected to each of the two element connection lines 67, and each branch line 68 branches from the middle of each element connection line 67. One end of each branch line 68 is connected to each element connection line 67, and the other end can be connected to each power supply connection line 66 via each switch 65.

In one embodiment, when a plurality of electrolytic capacitors 41A are provided, the number of thermoelectric conversion elements 50 and the number of temperature sensors 70 correspond to the number of electrolytic capacitors 41A, and each temperature sensor 70 is adjacent to each electrolytic capacitor 41A. And are placed. The number of switch units 56 and the number of power supply devices 51 may also correspond to the number of electrolytic capacitors 41A, and the connection structure of each switch unit 56, each power supply device 51, and each thermoelectric conversion element 50 is an embodiment shown in FIG. Is similar to. That is, the control system has a structure in which the thermoelectric conversion element 50 is connected in parallel to the power supply device 51 and the switch unit 56.

As shown in FIG. 4, the control device 55 is electrically connected to the switch unit 56 and includes a switch switching unit 33 that switches the switch 65 of the switch unit 56, and the switch switching unit 33 is connected to the operation control unit 32. It is connected. When the operation control unit 32 operates the switch switching unit 33, the switch switching unit 33 switches the switch 65 of the switch unit 56. More specifically, when the operation control unit 32 operates the switch switching unit 33 (first operation), the thermoelectric conversion element 50 and the power supply device 51 connect the power supply connection line 66, the branch line 68, and the element connection line 67. Connected via. When the operation control unit 32 operates the switch switching unit 33 (second operation), the thermoelectric conversion element 50 and the power supply device 51 are connected via the power supply connection line 66 and the element connection line 67.

7 and 8 are diagrams for explaining the direction of the current flowing through the thermoelectric conversion element 50. FIG. 7 shows the current flow when the direction of the current flowing through the thermoelectric conversion element 50 is the first current direction (that is, the direction in which the heat of the electrolytic capacitor 41A is transferred to the inverter mounting member 23). FIG. 8 shows the current flow when the direction of the current flowing through the thermoelectric conversion element 50 is the second current direction (that is, the direction in which the heat of the inverter mounting member 23 is transferred to the electrolytic capacitor 41A).

As shown in FIG. 7, the power connection line 66 and the branch line 68 are connected via the switch 65 by the first operation of the switch switching unit 33. When the power supply device 51 supplies electric power to the thermoelectric conversion element 50, a current flows through the power connection line 66, the branch line 68, and the element connection line 67 to the thermoelectric conversion element 50. Due to the current flowing in the first current direction, the thermoelectric conversion element 50 has a heat flow that moves from one surface (contact surface on the electrolytic capacitor side) 50a toward the opposite surface (contact surface on the inverter mounting member side) 50b. As a result, the electrolytic capacitor 41A is cooled.

As shown in FIG. 8, the power supply connection line 66 and the element connection line 67 are connected via the switch 65 by the second operation of the switch switching unit 33. When the power supply device 51 supplies electric power to the thermoelectric conversion element 50, the current flows to the thermoelectric conversion element 50 through the power supply connection line 66 and the element connection line 67. Due to the current flowing in the second current direction, a heat flow is generated in the thermoelectric conversion element 50, which moves from the opposite surface (inverter mounting member side contact surface) 50b toward one surface (electrolytic capacitor side contact surface) 50a. As a result, the electrolytic capacitor 41A is heated.

The reason for heating the electrolytic capacitor 41A is as follows. The inverter unit 3 may be used in an extremely cold environment such as a cold region. In this case, if the ambient temperature of the electrolytic capacitor 41A is low, the temperature of the electrolytic capacitor 41A also becomes low, and the capacitance of the electrolytic capacitor 41A may decrease. In this case, it is desirable to stabilize the power conversion performance of the inverter unit 3 by positively heating the electrolytic capacitor 41A to prevent a decrease in the capacitance of the electrolytic capacitor 41A. In the present embodiment, the control device 55 can heat the thermoelectric conversion element 50 via the thermoelectric conversion element 50 by controlling the operation of the switch unit 56, so that even if the ambient temperature of the electrolytic capacitor 41A is low, the electrolytic capacitor is an electrolytic capacitor. It is possible to prevent a decrease in the capacitance of 41A.

A heating start threshold value, which is a value of the temperature at which heating of the electrolytic capacitor 41A should be started, may be stored in the storage unit of the control device 55. The heating start threshold value is smaller than the cooling start threshold value and the power supply stop threshold value, and may be arbitrarily determined. The heating start threshold value is, for example, 0 [° C.].

FIG. 9 is a diagram showing a processing flow of the control device 55. The temperature sensor 70 detects the temperature of the electrolytic capacitor 41A (more specifically, the ambient temperature of the electrolytic capacitor 41A) at the time of starting the inverter unit 3 or immediately after starting the inverter unit 3, and the monitoring unit 30 detects the electrolytic capacitor 41A. (See step S201 in FIG. 9). The determination unit 31 compares the temperature of the electrolytic capacitor 41A detected by the temperature sensor 70 with the heating start threshold value (see step S202 in FIG. 9). When the temperature of the electrolytic capacitor 41A is equal to or lower than the heating start threshold value (see “YES” in step S202 of FIG. 9), the determination unit 31 sends a signal indicating the result to the operation control unit 32. When the operation control unit 32 receives the signal from the determination unit 31, the operation control unit 32 issues a command to the switch switching unit 33 to operate the switch unit 56.

The switch switching unit 33 operates the switch unit 56 to switch the direction of the current flowing through the thermoelectric conversion element 50 to the second current direction (see FIG. 8). The operation control unit 32 operates the power supply device 51 so that electric power is supplied to the thermoelectric conversion element 50. When the power supply device 51 supplies electric power to the thermoelectric conversion element 50, the current flows in the second current direction. As a result, the heat of the inverter mounting member 23 is transferred to the electrolytic capacitor 41A, and the electrolytic capacitor 41A is heated (see step S203 in FIG. 9). After that, the determination unit 31 determines whether or not the temperature of the electrolytic capacitor 41A has risen to the power supply stop threshold value (see step S204 in FIG. 9).

When the temperature of the electrolytic capacitor 41A is not equal to or lower than the heating start threshold value, that is, when the temperature of the electrolytic capacitor 41A is higher than the heating start threshold value (see “NO” in step S202 of FIG. 9), the control device 55 may be used. It is determined that the heating of the electrolytic capacitor 41A is unnecessary, and the heating operation of the electrolytic capacitor 41A is not executed.

When the temperature of the electrolytic capacitor 41A rises to the power supply stop threshold value (see “YES” in step S204 of FIG. 9), the determination unit 31 sends a signal indicating the result to the operation control unit 32. When the operation control unit 32 receives the signal from the determination unit 31, the operation control unit 32 operates the power supply device 51 to stop the supply of electric power from the power supply device 51 to the thermoelectric conversion element 50 (step of FIG. 9). See S205). When the temperature of the electrolytic capacitor 41A has not risen to the power supply stop threshold value (see “NO” in step S204 of FIG. 9), the monitoring unit 30 continues to monitor the temperature of the electrolytic capacitor 41A.

After step S205 in FIG. 9, the control device 55 executes the processing flow (steps S101 to S105) shown in FIG. More specifically, when the determination unit 31 determines that the temperature of the electrolytic capacitor 41A has risen to the cooling start threshold value (see “YES” in step S102 in FIG. 5), the operation control unit 32 is determined by the determination unit 31. A command is issued to the switch switching unit 33 to operate the switch unit 56 based on the signal indicating the determination result from.

The switch switching unit 33 operates the switch unit 56 to switch the direction of the current flowing through the thermoelectric conversion element 50 to the first current direction (see FIG. 7). The operation control unit 32 operates the power supply device 51 so that electric power is supplied to the thermoelectric conversion element 50. When the power supply device 51 supplies electric power to the thermoelectric conversion element 50, the current flows in the first current direction. As a result, the heat of the electrolytic capacitor 41A is transferred to the inverter mounting member 23, and the electrolytic capacitor 41A is cooled (see step S103 in FIG. 5). If the determination unit 31 does not determine that the temperature of the electrolytic capacitor 41A has risen to the cooling start threshold value (see “NO” in step S102 in FIG. 5), the monitoring unit 30 continues to monitor the temperature of the electrolytic capacitor 41A. do.

According to the present embodiment, by providing the switch unit 56 connected to the power supply device 51, the control device 55 sets the direction of the current input to the thermoelectric conversion element 50 via the switch unit 56 as the first current direction. It can be switched between the second current direction and the second current direction. With such a configuration, the control device 55 can accurately control the temperature of the electrolytic capacitor 41A so that the temperature of the electrolytic capacitor 41A is within a certain range.

FIG. 10 is a diagram showing another embodiment of the inverter unit 3. FIG. 11 is a diagram showing how the electrolytic capacitor 41A is housed in the capacitor case 75. Since the configuration of the present embodiment, which is not particularly described, is the same as that of the above-described embodiment, the duplicated description thereof will be omitted. As shown in FIGS. 10 and 11, the inverter unit 3 may include a capacitor case 75 that comes into contact with the inner surface 23a of the inverter mounting member 23 and houses the electrolytic capacitor 41A.

The capacitor case 75 is an accommodating member including a cylindrical wall portion 76 and a bottom portion 77 connected to the wall portion 76 and closing one end of the wall portion 76, and has a size capable of accommodating the electrolytic capacitor 41A. There is. The other end of the wall portion 76 is open, and the electrolytic capacitor 41A is inserted into the capacitor case 75 through this opening.

As shown in FIGS. 10 and 11, the thermoelectric conversion element 50 is attached to the inner surface of the capacitor case 75. When the electrolytic capacitor 41A is housed in the capacitor case 75, one surface (contact surface on the electrolytic capacitor side) 50a of the thermoelectric conversion element 50 comes into contact with the electrolytic capacitor 41A, and the opposite surface (condenser case side) of the thermoelectric conversion element 50. Contact surface) 50b contacts the inner surface of the capacitor case 75.

In the embodiment shown in FIGS. 10 and 11, the thermoelectric conversion element 50 is attached to the entire inner surface of the capacitor case 75. More specifically, the thermoelectric conversion element 50 is attached to the inner wall surface (inner peripheral surface) of the wall portion 76 of the capacitor case 75 and the inner surface of the bottom portion 77. In one embodiment, the thermoelectric conversion element 50 may be attached to a part of the inner surface of the capacitor case 75.

In the present embodiment, the thermoelectric conversion element 50 has the same thermoelectric conversion structure as the tape-shaped thermoelectric conversion element having a thin film shape described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2016-9838). The thermoelectric conversion element 50 having such a sheet shape is attached to the inner surface of the capacitor case 75 without any limitation on the arrangement location.

The insertion hole 42c of the substrate 42 has a size into which the capacitor case 75 can be inserted, and the diameter of the insertion hole 42c is larger than the outer diameter of the wall portion 76 of the capacitor case 75. In one embodiment, instead of providing the insertion hole 42c, a notch extending inward from the outer peripheral surface of the substrate 42 may be provided. The capacitor case 75 is inserted into the insertion hole 42c so that the bottom surface 60b of the main body 60 of the electrolytic capacitor 41A faces the inner surface 23a of the inverter mounting member 23 via the capacitor case 75. When the capacitor case 75 is inserted into the insertion hole 42c of the substrate 42, the outer surface of the bottom portion 77 of the capacitor case 75 comes into contact with the inner surface 23a of the inverter mounting member 23. The outer surface of the bottom 77 is a surface opposite to the inner surface of the bottom 77, which forms a part of the inner surface of the capacitor case 75.

The temperature sensor 70 is arranged adjacent to the capacitor case 75. In the present embodiment, the temperature sensor 70 is arranged on the mounting surface 42a of the substrate 42, but may be directly mounted on the capacitor case 75. The control device 55 monitors the temperature detected by the temperature sensor 70, and when this temperature rises to the cooling start threshold value, the power supply device 51 supplies electric power to the thermoelectric conversion element 50 to heat the electrolytic capacitor 41A. Is transmitted to the capacitor case 75. The heat transferred to the capacitor case 75 is transferred to the inverter mounting member 23, and as a result, the electrolytic capacitor 41A is dissipated through the capacitor case 75.

The capacitor case 75 is preferably made of a material (metal) having excellent thermal conductivity, such as aluminum (Al). According to the present embodiment, the capacitor case 75 can increase the contact area between the electrolytic capacitor 41A and the thermoelectric conversion element 50, so that the cooling performance of the thermoelectric conversion element 50 can be improved. Similarly, when heating the thermoelectric conversion element 50, the capacitor case 75 can improve the heating performance of the thermoelectric conversion element 50.

Also in the present embodiment, the cooling start threshold value, the power supply stop threshold value, and the heating start threshold value may be stored in the storage unit of the control device 55. The control device 55 controls the operation of the power supply device 51 (and the switch unit 56) based on the cooling start threshold value, the power supply stop threshold value, and the heating start threshold value, as in the above-described embodiment. You may.

The switch unit 56 has a direction of the current flowing through the thermoelectric conversion element 50 as a first current direction for transferring the heat of the electrolytic capacitor 41A to the capacitor case 75 and a second current direction for transmitting the heat of the capacitor case 75 to the electrolytic capacitor 41A. Switch between. When the temperature detected by the temperature sensor 70 rises to the cooling start threshold value, the control device 55 operates the switch unit 56 to switch the direction of the current flowing through the thermoelectric conversion element 50 to the first current direction. In this state, when the power supply device 51 supplies electric power to the thermoelectric conversion element 50, the heat of the electrolytic capacitor 41A is transferred to the inverter mounting member 23 via the capacitor case 75.

When the temperature is equal to or lower than the heating start threshold value, the control device 55 operates the switch unit 56 to switch the direction of the current flowing through the thermoelectric conversion element 50 to the second current direction. In this state, when the power supply device 51 supplies electric power to the thermoelectric conversion element 50, the heat of the inverter mounting member 23 is transferred to the electrolytic capacitor 41A via the capacitor case 75.

Hereinafter, an example of a mechanical device to which the inverter unit 3 can be applied will be described with reference to the drawings. FIG. 12 is a diagram showing a motor assembly 1 provided with an inverter unit 3. Since the configuration of the present embodiment, which is not particularly described, is the same as that of the above-described embodiment, the duplicated description thereof will be omitted.

The electric motor assembly 1 is a mechanical device having an integrated structure in which an inverter 20 is built. As shown in FIG. 12, the motor assembly 1 includes a motor unit 2 and an inverter unit 3 as an inverter unit. The motor assembly 1 includes a drive shaft 5, a motor (rotating element) 8 including a rotor 6 for rotating the drive shaft 5, and a stator (stator) 7, a motor casing 10 for accommodating the motor 8, and a motor casing 10. An inverter 20 arranged adjacent to the motor 8 and controlling the operation (rotational speed) of the motor 8 and an inverter 20 are housed and arranged in series with the motor casing 10 along the axis CL direction of the drive shaft 5. It is equipped with an inverter case 21.

The motor casing 10 and the inverter case 21 are arranged concentrically with the drive shaft 5. In the present embodiment, since the motor casing 10 and the inverter case 21 are arranged in series in the axis CL direction of the drive shaft 5, the motor assembly 1 can have a compact structure.

A motor 8 is arranged inside the motor casing 10. The motor 8 surrounds the rotor 6 fixed to the drive shaft 5 and the stator (stator) in which the winding (coil) 7b receives power from the outside (not shown) to form a rotating magnetic field. ) 7 and. The stator 7 includes a stator core 7a and a plurality of windings 7b wound around the stator core 7a. The rotor 6 is rotated by a rotating magnetic field formed between the rotor 6 and the stator 7, and the drive shaft 5 to which the rotor 6 is fixed rotates together with the rotor 6.

In FIG. 12, the motor 8 is schematically drawn. The motor 8 is, for example, a permanent magnet type motor using a permanent magnet in the rotor. However, the motor 8 is not limited to the permanent magnet type motor, and may be various types of motors such as an induction motor and an SR motor.

The motor casing 10 includes a tubular motor frame 11 to which the stator 7 is fixed, an end cover 12 in which one open end of the motor frame 11 is closed and a through hole 29 through which the drive shaft 5 penetrates is formed. It includes a bracket 13 that closes the other open end of the motor frame 11. The end cover 12 and the bracket 13 face each other with the motor 8 interposed therebetween. The drive shaft 5 is rotatably supported by a bearing 27 supported by the bearing support portion 25 of the end cover 12 and a bearing 28 supported by the bearing support portion 26 of the bracket 13.

On the outer surface of the motor frame 11, a plurality of fins 35 extending in the axis CL direction of the drive shaft 5 are arranged. These fins 35 extend outward from the outer surface of the motor frame 11 and are arranged at equal intervals along the circumferential direction of the motor frame 11. The outer surface of the motor frame 11 is a surface opposite to the inner surface of the motor frame 11 to which the stator 7 is fixed.

The inverter case 21 includes a cylindrical inverter frame 22 that surrounds the inverter 20, and an inverter mounting member 23 that closes the open end of the inverter frame 22. The inverter mounting member 23 may also be referred to as a cover member. On the outer surface of the inverter frame 22, a plurality of fins 37 extending in the axis CL direction of the drive shaft 5 are arranged. These fins 37 extend outward from the outer surface of the inverter frame 22, and are arranged at equal intervals along the circumferential direction of the inverter frame 22. The outer surface of the inverter frame 22 is a surface opposite to the inner surface of the inverter frame 22 arranged around the inverter 20.

The surface of the inverter frame 22 on the inverter mounting member 23 side and the surface of the inverter mounting member 23 on the inverter frame 22 side each have a fitting structure, and the inverter frame 22 and the inverter mounting member 23 are fitted to each other by fitting. It is connected.

The surface of the inverter frame 22 on the bracket 13 side and the surface of the bracket 13 on the inverter frame 22 side each have a fitting structure, and the inverter frame 22 and the bracket 13 are connected to each other by fitting.

As shown in FIG. 12, the motor assembly 1 has a closed structure, and the inverter 20, that is, the inverter element 41 and the substrate 42 are arranged in the closed space formed by the inverter case 21 and the bracket 13. When the inverter 20 which is a heat generating source is driven in such a closed space, the ambient temperature of the electrolytic capacitor 41A tends to be relatively high, and the life of the electrolytic capacitor 41A may be shortened. Therefore, in the motor assembly 1 having such a closed structure, it is more necessary to positively cool the electrolytic capacitor 41A to extend the life of the electrolytic capacitor 41A.

In order to dissipate heat from the electrolytic capacitor 41A, it is conceivable to increase the size of the enclosed space in which the inverter 20 is arranged, or increase the size of the inverter mounting member 23 as a heat sink. However, in such a configuration, the overall size of the motor assembly 1 becomes large.

According to the present embodiment, the thermoelectric conversion element 50 can positively dissipate heat of the electrolytic capacitor 41A to the inverter mounting member 23 due to its Pelche effect, so that a large space for dissipating heat of the electrolytic capacitor 41A is not required. .. Therefore, the size of the enclosed space in which the inverter 20 is arranged can be made relatively small, and the size of the inverter mounting member 23 can also be made relatively small. As a result, the motor assembly 1 can be reduced in size overall. Although not shown, the configuration of the inverter unit 3 provided with the capacitor case 75 (see FIGS. 10 and 11) can also be applied to the motor assembly 1.

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

1 Motor assembly 2 Motor part 3 Inverter unit (inverter part)
5 Drive shaft 6 Rotor 7 Capacitor 7a Stator core 7b Winding 8 Motor 10 Motor casing 11 Motor frame 12 End cover 13 Bracket 20 Inverter 21 Inverter case 22 Inverter frame 23 Inverter mounting member 23a Inner surface 23b Outer surface 25 Bearing support 26 Bearing support Part 27 Bearing 28 Bearing 29 Through hole 30 Monitoring part 31 Judgment part 32 Operation control part 33 Switch switching part 35, 36, 37 Fins 41 Inverter element 41A Electrolytic capacitor 41B Power element 42 Board 42a Mounting surface 42b Back surface 42c Insertion hole 50 Thermoelectric conversion Element 50a One side 50b Opposite side 51 Power supply 55 Control device 56 Switch part 60 Main body 60a Terminal surface 60b Bottom surface 60c Outer surface 61 Terminal 62 Lead wire 65 Switch 66 Power connection line 67 Element connection line 68 Branch line 70 Temperature Sensor 75 Capacitor case 76 Wall 77 Bottom

Claims (8)

Inverter elements including electrolytic capacitors and
The board to which the electrolytic capacitor is connected and
Inverter mounting member to which the board is mounted and
A thermoelectric conversion element arranged between the electrolytic capacitor and the inner surface of the inverter mounting member,
A power supply device that is electrically connected to the thermoelectric conversion element and supplies electric power to the thermoelectric conversion element.
It is provided with a control device that is electrically connected to the power supply device and controls the operation of the power supply device.
The thermoelectric conversion element has one surface in contact with the electrolytic capacitor and the opposite surface located on the opposite side of the one surface and in contact with the inner surface of the inverter mounting member.
The substrate is arranged parallel to the inner surface of the inverter mounting member, and has an insertion hole having a size into which the electrolytic capacitor can be inserted.
The electrolytic capacitor is inserted into the insertion hole so that the bottom surface of the electrolytic capacitor faces the inner surface of the inverter mounting member via the thermoelectric conversion element.
The control device is an inverter unit characterized in that electric power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the inverter mounting member. The inverter unit includes a temperature sensor arranged adjacent to the electrolytic capacitor.
The control device is
Monitor the temperature detected by the temperature sensor and
The first aspect of the present invention is characterized in that when the temperature rises to the cooling start threshold value, electric power is supplied from the power supply device to the thermoelectric conversion element to transfer the heat of the electrolytic capacitor to the inverter mounting member. The described inverter unit. In the inverter unit, the direction of the current flowing through the thermoelectric conversion element is the first current direction for transmitting the heat of the electrolytic capacitor to the inverter mounting member and the second current for transmitting the heat of the inverter mounting member to the electrolytic capacitor. Equipped with a switch to switch between directions
The control device is
When the temperature rises to the cooling start threshold value, the switch unit is operated to switch the direction of the current flowing through the thermoelectric conversion element to the first current direction.
When the temperature is equal to or less than the heating start threshold value smaller than the cooling start threshold value, the switch unit is operated to switch the direction of the current flowing through the thermoelectric conversion element to the second current direction. The inverter unit according to claim 2. Inverter elements including electrolytic capacitors and
The board to which the electrolytic capacitor is connected and
Inverter mounting member to which the board is mounted and
A capacitor case that comes into contact with the inner surface of the inverter mounting member and houses the electrolytic capacitor,
The thermoelectric conversion element attached to the inner surface of the capacitor case and
A power supply device that is electrically connected to the thermoelectric conversion element and supplies electric power to the thermoelectric conversion element.
It is provided with a control device that is electrically connected to the power supply device and controls the operation of the power supply device.
The thermoelectric conversion element has one surface in contact with the electrolytic capacitor and the opposite surface located on the opposite side of the one surface and in contact with the inner surface of the capacitor case.
The substrate is arranged parallel to the inner surface of the inverter mounting member, and has an insertion hole having a size capable of inserting the capacitor case.
The capacitor case is inserted into the insertion hole so that the bottom surface of the electrolytic capacitor faces the inner surface of the inverter mounting member via the capacitor case.
The control device is an inverter unit characterized in that electric power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the capacitor case. The inverter unit includes a temperature sensor arranged adjacent to the capacitor case.
The control device is
Monitor the temperature detected by the temperature sensor and
The fourth aspect of claim 4 , wherein when the temperature rises to the cooling start threshold value, electric power is supplied from the power supply device to the thermoelectric conversion element to transfer the heat of the electrolytic capacitor to the capacitor case. Inverter unit. In the inverter unit, the direction of the current flowing through the thermoelectric conversion element is the first current direction for transmitting the heat of the electrolytic capacitor to the capacitor case and the second current direction for transmitting the heat of the capacitor case to the electrolytic capacitor. Equipped with a switch section to switch between
The control device is
When the temperature rises to the cooling start threshold value, the switch unit is operated to switch the direction of the current flowing through the thermoelectric conversion element to the first current direction.
When the temperature is equal to or less than the heating start threshold value smaller than the cooling start threshold value, the switch unit is operated to switch the direction of the current flowing through the thermoelectric conversion element to the second current direction. The inverter unit according to claim 5 . Drive shaft and
A motor including a rotor and a stator that rotate the drive shaft,
The motor casing that houses the motor and
It is equipped with an inverter unit for controlling the rotation speed of the motor.
The inverter unit is
Inverter elements including electrolytic capacitors and
The board to which the electrolytic capacitor is connected and
An inverter mounting member that closes the open end of the inverter frame connected to the motor casing and to which the substrate is mounted.
A thermoelectric conversion element arranged between the electrolytic capacitor and the inner surface of the inverter mounting member,
A power supply device that is electrically connected to the thermoelectric conversion element and supplies electric power to the thermoelectric conversion element.
It is provided with a control device that is electrically connected to the power supply device and controls the operation of the power supply device.
The thermoelectric conversion element has one surface in contact with the electrolytic capacitor and the opposite surface located on the opposite side of the one surface and in contact with the inner surface of the inverter mounting member.
The substrate is arranged parallel to the inner surface of the inverter mounting member, and has an insertion hole having a size into which the electrolytic capacitor can be inserted.
The electrolytic capacitor is inserted into the insertion hole so that the bottom surface of the electrolytic capacitor faces the inner surface of the inverter mounting member via the thermoelectric conversion element.
The control device is an electric motor assembly characterized in that electric power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the inverter mounting member. Drive shaft and
A motor including a rotor and a stator that rotate the drive shaft,
The motor casing that houses the motor and
It is equipped with an inverter unit for controlling the rotation speed of the motor.
The inverter unit is
Inverter elements including electrolytic capacitors and
The board to which the electrolytic capacitor is connected and
An inverter mounting member that closes the open end of the inverter frame connected to the motor casing and to which the substrate is mounted.
A capacitor case that comes into contact with the inner surface of the inverter mounting member and houses the electrolytic capacitor,
The thermoelectric conversion element attached to the inner surface of the capacitor case and
A power supply device that is electrically connected to the thermoelectric conversion element and supplies electric power to the thermoelectric conversion element.
It is provided with a control device that is electrically connected to the power supply device and controls the operation of the power supply device.
The thermoelectric conversion element has one surface in contact with the electrolytic capacitor and the opposite surface located on the opposite side of the one surface and in contact with the inner surface of the capacitor case.
The substrate is arranged parallel to the inner surface of the inverter mounting member, and has an insertion hole having a size capable of inserting the capacitor case.
The capacitor case is inserted into the insertion hole so that the bottom surface of the electrolytic capacitor faces the inner surface of the inverter mounting member via the capacitor case.
The control device is an electric motor assembly characterized in that electric power is supplied from the power supply device to the thermoelectric conversion element and the heat of the electrolytic capacitor is transferred to the capacitor case.

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