JP2005328675A - Inverter module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inverter module that enables reduction in installation space. <P>SOLUTION: This inverter module 35 is structured by providing in a molded package 40 a switching element group 12 for converting a DC current into a three-phase pseudo-AC voltage by switching. A diode 19 which is provided between a battery 1 as a DC power source and the switching element group 12 and in which the switching element group 12 side is arranged as the forward direction is integrally molded in the molded package 40. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inverter module in which a switching element group for converting a DC voltage into a three-phase pseudo AC voltage by switching is provided in a molded package.

  In recent years, an air conditioner equipped with an electric compressor driven by a battery power source has been developed as an air conditioner for an electric vehicle. As shown in FIG. 6, the air conditioner includes a battery (DC power supply) 101, a switch 102 as a switch connected in series to the battery 101, a switch 104 connected in parallel with the switch 102, The charging device 111 includes a switch 103, an inverter module 105, a capacitor 106, and an electric compressor 110.

  The inverter module 105 is configured by molding a switching element group 112 including a switching element 114 and a diode (not shown) for absorbing a switching surge in a mold package 115. The switching element group 112 is for converting a DC voltage from the battery 101 into a three-phase pseudo AC voltage and applying it to the electric compressor 110 to drive the motor of the electric compressor 110.

The capacitor 106 is for stably supplying a voltage to the switching element group 112. The resistor 104 of the charging device 111 is for suppressing an inrush current flowing in the capacitor 106 and an inrush voltage generated in the capacitor 106 when a DC voltage of the battery 101 is applied. That is, the presence of the resistor 104 opens the switch 102 when the battery 101 is connected, closes the switch 103, and causes a current to flow through the resistor 104, thereby causing an inrush that occurs when the voltage of the battery 101 is applied. Current can be suppressed. As a result, it is possible to avoid inconvenience that a high current or a high voltage is applied to the inverter module 105 and the switching element group 112 in the inverter module 105 is damaged (for example, refer to Patent Document 1).
Japanese Patent No. 3341327

  In such an air conditioner, when the battery 101 is reversely connected, the capacitor 106 and the switching element group 112 are damaged. In addition, when a person touches the terminal on the battery 101 side, there is a disadvantage that an electric shock is caused by the charge of the capacitor 106. In order to prevent this, in the past, for example, there has been a case where a diode whose forward direction is the capacitor 106 is attached to the charging device 111.

  However, the addition of such a diode causes an increase in the size of the entire device. On the other hand, especially in an air conditioner for an electric vehicle, since it is mounted on a vehicle for driving an electric compressor, it must be installed in a narrow engine room with a limited installation space. On the contrary, it was necessary to further reduce the size.

  The present invention has been made to solve the problems of the related art, and an object thereof is to provide an inverter module capable of reducing the installation space.

  The inverter module according to the present invention includes a switching element group for converting a DC voltage into a three-phase pseudo AC voltage by switching in a molded package, and is provided between the DC power source and the switching element group. A diode whose forward direction is on the switching element group side is integrally molded in a mold package.

  The inverter module of the invention of claim 2 is provided with a pin for connecting the capacitor charged from the DC power source through the charging device in the above invention to the forward direction side of the diode.

  In the present invention, in an inverter module in which a switching element group for converting a DC voltage into a three-phase pseudo AC voltage by switching is provided in a mold package, the switching element is provided between the DC power source and the switching element group. The diode with the forward side on the group side is molded in the molded package as a single unit, so that the diode can be significantly reduced in size compared to the case where the diode for preventing damage and electric shock from reverse connection of the DC power supply is provided on the external substrate. , Will be able to reduce the installation space. In addition, since the diode can dissipate heat and the insulation distance can be secured at the same time, a high-performance inverter module can be configured.

  In the invention of claim 2, in addition to the above-described invention, a pin for connecting a capacitor charged from a DC power source through a charging device to the forward direction side of the diode is provided, so that the diode and the capacitor can be connected without any trouble. Will be able to.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a power circuit diagram of an embodiment of an air conditioner for an electric vehicle equipped with an inverter module 35 of the present invention, and FIG. 2 is a perspective view of the inverter module 35 of the present invention.

  In FIG. 1, reference numeral 1 denotes a main battery as a DC power source for an electric vehicle, an electric compressor 10 of an air conditioner, a switch 2, a charging circuit 7 as a charging device, a capacitor 30, a discharge resistor 31, and an inverter module of the present invention. DC power is supplied through an inverter device 8 composed of 35 or the like. A direct current voltage is output from the battery 1, and the electric compressor 10 is supplied with a voltage converted into a three-phase pseudo alternating current by an inverter module 35 described later.

  The inverter module 35 described above is provided with the switching element group 12 for converting the voltage into a three-phase pseudo-AC voltage by switching in the molded package 40. The switching element group 12 includes a switching element 14 and a diode (not shown) for absorbing a switching surge, and is connected between the plus line 4 (about DC + 300V) and the minus line 6 of the battery 1.

  The switch 2 is connected to a plus line 4 between the battery 1 and the switching element group 12. The capacitor 30 is for supplying a stable voltage to the switching element group 12, and is connected between the switch 2 and the switching element group 12 between the plus line 4 and the minus line 6. The discharge resistor 31 is for discharging the charge charged in the capacitor 30, and is connected between the plus line 4 and the minus line 6 between the capacitor 30 and the switching element group 12. This resistor 31 is molded in the mold package 40.

  The charging circuit 7 is composed of a series circuit of a switch 3, a positive temperature coefficient thermistor 18 and a diode 19 described later, and is connected to the switch 2 in parallel. The charging circuit 7 is for suppressing an inrush current flowing in the capacitor 30 and an inrush voltage generated in the capacitor 30 when the voltage of the battery 1 is applied.

  That is, the controller 60 of the inverter device 8 first closes the switch 3 in a state where the switch 2 is opened (dissociated) based on an operation command from a controller (not shown) of the air conditioner, and supplies the current from the battery 1. The capacitor 30 is charged through the positive temperature coefficient thermistor 18 and the diode 19 to be charged. Since the positive temperature coefficient thermistor 18 self-heats and increases the resistance value, the positive temperature coefficient thermistor 18 functions to suppress an increase in the flowing current value. Thereby, inrush current is suppressed and the capacitor 30 and the switching element group 12 are protected.

  Next, when the charging of the capacitor 30 is completed, the controller 60 closes the switch 2 and then opens the switch 3 of the charging circuit 7. Thereafter, the voltage of the battery 1 is supplied to the switching element group 12 via the switch 2. Is applied. The controller 60 controls the ON / OFF of the switching element 14 of the switching element group 12 to generate a three-phase pseudo AC voltage having a predetermined frequency, and applies and drives the motor of the electric compressor 10.

  Then, based on the operation designation command from the controller of the air conditioner, the controller 60 opens (breaks) the switch 2 and stops the operation of the electric compressor 10.

  On the other hand, the diode 19 described above is provided between the battery 1 and the switching element group 12 in the charging circuit 7, and the switching element group 12 side is in the forward direction. That is, the diode 19 of this embodiment is installed between the battery 1 and the switching element group 12 in the charging circuit 7 of the plus line 4 for charging the capacitor 30 from the battery 1 with the capacitor 30 side in the forward direction. .

  When the battery 1 is reversely connected by the diode 19, a reverse voltage is applied via the charging circuit 7, the capacitor 30, the switching element group 12, or the like is damaged, or the battery 1 side terminal is It is possible to prevent inconvenience of electric shock when touched by a hand.

  In the present invention, the diode 19 described above is integrally molded in the mold package 40 together with the switching element group 12.

  Here, the conventional diode has been arranged on the circuit board, so that there has been a problem that the inverter device is enlarged. On the other hand, when such an inverter device is mounted on a vehicle for driving an electric compressor of an air conditioner for an electric vehicle as in the present embodiment, it must be installed in a narrow engine room with a limited installation space. It is necessary to reduce the size.

  Therefore, the inverter device 8 can be significantly downsized by integrally molding the diode 19 in the molded package 40 as in the present invention. Thereby, the installation space of the inverter apparatus 8 provided with the said inverter module 35 can be reduced.

  Further, by molding the diode 19, the heat radiation of the diode 19 can be performed by the heat radiation means (heat radiation fin or the like) of the inverter module 35. Therefore, it is not necessary to install a special heat dissipating means for heat dissipation of the resistor, and the number of parts can be reduced. Furthermore, it is possible to secure an insulation distance of the diode 19. Therefore, a high-performance inverter module 35 can be provided.

  On the other hand, the inverter device 8 is provided with voltage dividing resistors 50, 51, 52, 53 for detecting the voltage before and after the switch 2. That is, a series circuit (voltage detection circuit) of resistors 50 and 51 is connected between the plus line 4 at a position between the switch 30 and the capacitor 30 at the rear stage of the switch 2 and the minus line 6 of the battery 1.

  Further, a series circuit (voltage detection circuit) of resistors 52 and 53 is connected between the plus line 4 and the minus line 6 at a position between the battery 1 and the preceding stage of the switch 2. The resistors 50 and 51 are for detecting the voltage at the rear stage of the switch 2, and the resistors 52 and 53 are for detecting the voltage at the front stage of the switch 2.

  In the embodiment, the resistors 50 and 52 have the same resistance value, and similarly, the resistors 51 and 53 have the same resistance value. The resistance values of the resistors 50 and 52 are sufficiently larger than the resistors 51 and 53 connected to the negative line 6 side. Then, the terminal voltages of the resistors 51 and 53 are input to the controller 60.

  Here, when the battery 1 is connected, the terminal voltage V1 of the resistor 51 input to the controller 60 is substantially the voltage of the battery 1 regardless of the open / close state of the switch 2. When the switch 30 is fully discharged in the state where the capacitor 30 is completely discharged, the terminal voltage V2 of the resistor 53 input to the controller 60 is zero, and when the switch 2 is closed, the voltage V2 is substantially equal to the voltage. V1 (with some voltage drop). Thereby, the open / close state of the switch 2 can be detected from the terminal voltages V 1 and V 2 of the resistors 51 and 53 input to the controller 60. Accordingly, it is possible to determine a state in which the switch 2 is closed despite the control of the switch 2 being opened by the controller 60, that is, so-called welding of the switch 2.

  The mold package 40 is provided with pins 20... For connecting the switching element group 12 and the discharge resistor 31 in the mold package 40, the battery 1 outside the mold package 40, the switch 2, and the electric compressor 10. It has been. With these pins 20..., Devices inside and outside the mold package 40 can be connected without hindrance.

  The mold package 40 is also provided with pins 22 for connecting the diode 19 to the charging circuit 7 outside the mold package 40. With such pins 22 and 22, even when the diode 19 is provided in the mold package 40 as in the present invention, it can be connected to the charging circuit 7 which is the front stage of the capacitor 30 outside the mold package 40 without any trouble. become.

  Next, another embodiment of the inverter module of the present invention will be described with reference to FIG. FIG. 3 shows a power supply circuit diagram of an embodiment of an air conditioner for an electric vehicle provided with the inverter module 135 in this case. In FIG. 3, the same reference numerals as those in FIGS. 1 and 2 indicate the same or similar effects.

  In FIG. 3, reference numeral 135 denotes the inverter module of the present embodiment, and the electric compressor 10 is supplied with the voltage converted into the three-phase pseudo alternating current by the inverter module 135.

  This inverter module 135 is provided with a switching element group 12 for converting a voltage into a three-phase pseudo-AC voltage by switching in the mold package 40 as in the above embodiment. The switching element group 12 includes a switching element 14 and a diode (not shown) for absorbing a switching surge, and is connected between the plus line 4 (about DC + 350V) and the minus line 6 of the battery 1.

  Here, a diode 70 is built in the inverter module 135 of the present embodiment. The diode 70 is provided between the battery 1 and the switching element group 12, and the switching element group 12 side is in the forward direction. The diode 70 of this embodiment is provided on the plus line 4 between the series circuit (voltage detection circuit) of the resistor 50 and the resistor 51 and the capacitor 30. That is, the diode 70 is connected to the plus line 4 between the connection point of the resistors 50 and 51 and the connection point of the capacitor 30, and the capacitor 30 side is in the forward direction.

  The mold package 40 is provided with pins 20 for connecting the switching element group 12 in the mold package 40 to the battery 1, the switch 2, the electric compressor 10, etc. outside the mold package 40. . With these pins 20..., Devices inside and outside the mold package 40 can be connected without hindrance.

  Further, a pin 23 for connecting the capacitor 30 charged from the battery 1 via the charging circuit 7 to the forward direction side of the diode 70 as described above is also provided. With this pin 23, the capacitor 30 can be connected to the forward direction side of the diode 70 in the molded package 40 without any trouble. The pin 23 is also provided as shown in FIG.

  Next, the operation of the inverter device 8 of the present invention having the above configuration will be described with reference to FIGS. Here, FIG. 4 is a flowchart for explaining the control relating to the welding detection operation of the switch 2 by the controller 60 of the inverter device 8, and FIG. 5 is a timing chart for explaining the operations of the switch 2, the switch 3 and the electric compressor 10. It is. It is assumed that the controller 60 controls the switches 2 and 3 in a state where the electric vehicle is not activated.

  When the electric vehicle is started in step S1 of FIG. 4 (ING (ignition) ON), the controller 60 receives an operation command signal from a controller of an air conditioner (not shown) provided in the vehicle interior in step S2. Judge whether or not. Now, if the temperature in the passenger compartment is higher than the set value and an operation command signal is input to the controller 60 from the controller of the air conditioner, the controller 60 sets the terminal voltage of the resistor 53 in the previous stage of the switch 2 in step S3. Based on this, it is determined whether or not the voltage V1 of the positive line 4 in the preceding stage of the switch 2 is higher than + 250V and lower than + 400V. At this time, when the voltage of the battery 1 is normal, the voltage V1 of the plus line 4 in front of the switch 2 input to the controller 60 is substantially the same as the voltage of the battery 1 (regardless of the open / close state of the switch 2). + 350V). Therefore, when the voltage V1 input to the controller 60 is + 250V or lower or + 400V or higher, it is determined that the voltage of the battery 1 is abnormal, and the controller 60 proceeds to step S7 and outputs a control output to the inverter device 8. Is stopped and a predetermined alarm operation is performed.

  On the other hand, when the voltage V1 of the plus line 4 in the previous stage of the switch 2 input to the controller 60 in step S3 of FIG. 4 is higher than 250V and lower than 400V, the voltage of the battery 1 is determined to be normal, and the controller 60 It progresses to step S4 and it is determined whether the voltage V2 of the plus line 4 of the back | latter stage of the switch 2 detected based on the terminal voltage of the resistance 51 of the back | latter stage of the switch 2 is higher than V1-10V. Here, at this time, the controller 60 controls to break the switch 2 and the switch 3. In addition, since the diode 70 has a forward direction on the capacitor 30 side, even if the capacitor 30 is charged, if the switch 2 and the switch 3 are in a normal state, the plus line at the rear stage of the switch 2 The voltage V2 of 4 becomes zero. Accordingly, when the voltage V2 is higher than the voltage V1-10V (10V is foreseeing the voltage drop of the circuit) before the control for closing the switch 2 and the switch 3 is performed, the switch 2 or the switch It can be determined that 3 is welded and closed.

  That is, the controller 60 compares the voltage V1 of the plus line 4 before the switch 2 with the voltage V2 of the plus line 4 after the switch 2, and the difference (V1−V2) is within a predetermined range (in the embodiment). If it is within the range of less than 10V, it is determined that the switch 2 or the switch 3 is welded and closed, the process proceeds to step S5, the control output to the inverter device 8 is stopped, and a predetermined alarm is given. Thereby, since the switching element 14 is not turned on, the motor of the compressor 10 is not energized.

  On the other hand, when the switch 2 and the switch 3 are not welded and are open, the voltage V2 input to the controller 60 is zero as described above, so the difference (V1−V2) is 10V or more. . Therefore, when the value of the voltage V1-10V is equal to or higher than the voltage V2 in step S4, the controller 60 determines that the switch 2 and the switch 3 are not welded and proceeds from step S4 to step S6. Then, the control of FIG. 5 is started.

  That is, the controller 60 first closes the switch 3 while the switch 2 is open (the switch 2 is broken), and the current from the battery 1 is passed through the positive temperature coefficient thermistor 18 and the diode 70. Flow through capacitor 30 and charge them. Since the positive temperature coefficient thermistor 18 increases its resistance by self-heating, it functions to suppress the resistance of the flowing current value. Thereby, inrush current can be suppressed and the capacitor 30 and the switching element group 12 can be protected.

  Next, the controller 60 closes the switch 2 at the timing when the charging of the capacitor 30 is completed (in this embodiment, 3 seconds after closing the switch 3), and then (closes the switch 2 in this embodiment). 1 second after that), the voltage of the battery 1 is applied to the switching element group 12 via the switch 2 after the switch 3 of the charging circuit 7 is opened. Further, the controller 60 controls ON / OFF of the switching element 14 of the switching element group 12 to generate a three-phase pseudo AC voltage having a predetermined frequency, and applies it to the motor of the electric compressor 10 to drive the motor at the above operating frequency. To do.

  When an operation stop signal is input from the controller of the air conditioner, the controller 60 opens (breaks) the switch 2, stops the power supply to the switching element group 12, and stops the operation of the electric compressor 10. To do. The charge of the capacitor 30 is discharged by the discharge resistor 31 with a predetermined time constant. However, if the switch 2 and the switch 3 are open, the voltage of the battery 1 is not applied. The voltage V2 of the plus line 4 subsequent to the switch 2 falls to zero at the moment when the switch 2 is opened.

  Here, immediately after opening the switch 2, the controller 60 compares the voltage V2 with the voltage V1, and the voltage V2 becomes higher than the voltage V1-10V (10V is in anticipation of a voltage drop in the circuit) as described above. Judge whether or not. When the difference (V1−V2) is within a predetermined range (a range smaller than 10V as described above), it is determined that the switch 2 or the switch 3 is welded and closed, and similarly to the inverter device 8 described above. The control output is stopped and a predetermined alarm is issued. As a result, the switching element 14 is not turned on, and the motor of the compressor 10 is not energized.

  By the way, even if the switch 2 is open in the past, the voltage V2 of the plus line 4 subsequent to the switch 2 becomes the charging voltage of the capacitor 30 and does not become zero until the capacitor 30 is completely discharged. That is, even if the switch 2 is opened, the voltage V2 becomes a high value until the charge charged in the capacitor 30 is completely discharged from the discharge resistor 31, so that the switch 2 or the switch 3 is assumed to be welded. However, it could not be judged immediately from the voltage V2.

  On the other hand, by installing the diode 70 with the capacitor 30 in the forward direction on the plus line 4 between the connection point of the resistor 50 and the connection point of the capacitor 30, no current flows in the reverse direction, so the capacitor 30 is completely discharged. Even before, if the switch 2 is normally broken, the voltage V2 instantaneously becomes zero. Thus, even before the capacitor 30 is completely discharged, the open / close state of the switch 2 can be detected by comparing the voltage V1 and the voltage V2 as described above. It becomes possible to determine the welding of the vessel 3 at an early stage.

  In addition, when the battery 1 is reversely connected due to the diode 70, the capacitor 30, the switching element group 12, or the like is damaged, or when a person touches the terminal on the battery 1 side, It is possible to prevent inconvenience of electric shock. As a result, the safety and reliability of the inverter device 8 can be improved.

  Further, by integrally molding the diode 70 in the mold package 40 as described above, the inverter device 8 can be significantly reduced in size. Thereby, the installation space of the inverter apparatus 8 provided with the said inverter module 135 can be reduced.

  Further, by molding the diode 70, the diode 70 can be radiated by the radiating means (such as a radiating fin) of the inverter module 135. Therefore, it is not necessary to install a special heat dissipating means for heat dissipation of the resistor, and the number of parts can be reduced. Furthermore, the insulation distance of the diode 70 can be secured. Therefore, a high-performance inverter module 135 can be provided.

In the embodiment, the switch 3 is provided in the charging circuit 7. However, the present invention is not limited to this, and the switch is provided in the plus line 4 immediately after the battery 1 (before the switch 2) without being provided in the charging circuit 7. Also good.
In addition, each numerical value shown in the present embodiment is not limited thereto.

It is an electric circuit diagram of one Example of the air conditioner for electric vehicles provided with the inverter module of this invention. It is a perspective view of the inverter module in the state molded in the mold package. It is an electric circuit diagram of the other Example of the electric vehicle air conditioner provided with the inverter module of this invention. It is a control flowchart of the controller of the inverter apparatus provided with the inverter module of FIG. It is a timing chart which shows operation | movement of the switch and electric compressor of an inverter apparatus provided with the inverter module of FIG. It is an electric circuit diagram of the air-conditioner for electric vehicles provided with the conventional inverter module.

Explanation of symbols

1 Battery 2 Switch (switching device)
3 Switch 7 Charging circuit (charging device)
8 Inverter device 10 Electric compressor 12 Switching element group 14 Switching element 19, 70 Diode 20, 22, 23 Pin 30 Capacitor 31, 50, 51, 52, 53 Resistor 35, 135 Inverter module 60 Controller

Claims (2)

In an inverter module in which a switching element group for converting a DC voltage into a three-phase pseudo AC voltage by switching is provided in a mold package,
An inverter module, wherein a diode provided between a direct current power source and the switching element group, the switching element group side being a forward direction, is integrally molded in the mold package.   The inverter module according to claim 1, further comprising a pin for connecting a capacitor charged from the DC power source through a charging device to a forward direction side of the diode.

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