JP5125458B2 - Power conversion circuit control device and power conversion system - Google Patents

Description

  The present invention includes a high-potential side switching element that is connected between a rotating machine and a power feeding means, and that connects the rotating machine to a high-potential side, and a low-potential-side switching element that connects the rotating machine to a low-potential side. A control device for a power conversion circuit that is applied to a power conversion circuit including a plurality of series connection bodies and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state, and a power conversion system including the same About.

  For example, when power is supplied to a three-phase motor, a three-phase inverter that converts a DC voltage into an AC voltage is usually used. Thereby, an alternating voltage can be applied to each phase of the three-phase motor. The maximum value of the output voltage of this inverter is limited by the voltage of the DC power supply. For this reason, it is also well known that a booster circuit is provided between the DC power supply and the inverter. However, when a booster circuit is provided, a driver or the like for turning on / off a switching element of the booster circuit is provided, and an increase in the number of components cannot be ignored.

Therefore, conventionally, as seen in Patent Document 1 below, for example, it has been proposed to provide an impedance network between the inverter and the DC power supply. According to this, by short-circuiting the upper and lower arms of the inverter, it is possible to boost the voltage of the DC power supply using the inductor constituting the impedance network. Therefore, the boosting operation can be performed only by operating the switching element of the inverter, and an increase in the number of parts can be suppressed.
US Pat. No. 7,130,205

  By the way, according to the process of short-circuiting the upper and lower arms, although the voltage of the DC power supply can be boosted, the temperature of the switching element may be made uneven by performing such a process. And when the temperature of a switching element becomes high too much, there exists a possibility that the reliability of a switching element may fall.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a high-potential-side switching element that is connected between a rotating machine and a power feeding means and that connects the rotating machine to a high-potential side. When performing a process of turning on the switching element so as to put the series connection body in a short circuit state in a power conversion circuit including a plurality of series connection bodies with a low potential side switching element that connects the rotating machine to the low potential side. An object of the present invention is to provide a control device for a power conversion circuit capable of suppressing an excessive temperature rise of a switching element, and a power conversion system including the same.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

According to a fourth aspect of the present invention, there is provided a high-potential-side switching element that is connected between the rotating machine and the power supply means, and that connects the rotating machine to the high-potential side, and a low-potential side that connects the rotating machine to the low-potential side. In a control device for a power conversion circuit that is applied to a power conversion circuit including a plurality of serially connected bodies with a switching element, and that performs a process of turning on the switching elements so that the serially connected body is in a short circuit state, the short circuit state Is to turn on both the high-potential-side switching element and the low-potential-side switching element that constitute the same series-connected body, and the power converter circuit short-circuits the series-connected body. The voltage of the power feeding means is boosted, and the rotating machine is driven by applying an AC voltage to the rotating machine by operating the power conversion circuit. In air, a series connection to the short-circuited state, characterized in that it comprises a setting means for variably set in accordance with the parameter correlated with the temperature of the switching element.

  Since the current that passes through the switching element on the high potential side and the switching element on the low potential side flows through the series connection body in the short-circuit state, the temperature is likely to rise. In the above invention, since the process for setting the short-circuit state, which is a process that easily induces a temperature rise, is variably set according to a parameter having a correlation with the temperature, an excessive temperature rise of the switching element can be suppressed.

The invention according to claim 5 is the invention according to claim 1 or 3 , wherein the power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short circuit state. To do.

  In the above invention, the provision of the setting means can suppress an excessive temperature rise of the switching element during the boosting operation.

  Note that the power conversion circuit includes the following: “Equipped with an inductor, and when the series connection body is short-circuited, energy stored in the inductor is released when the short-circuit state of the series connection body is released. Boosting the voltage of the power feeding means using the phenomenon "or" the power feeding means using the phenomenon of having an inductor and generating an electromotive force in the inductor by releasing the short-circuit state of the series connection body " It is desirable that the voltage is boosted.

According to a sixth aspect of the present invention, in the invention according to the fourth or fifth aspect , the power conversion circuit includes an inductor connected between the switching element on the high potential side and a positive terminal of the power feeding unit, and the low potential side. A pair of inductors composed of an inductor connected between a switching element and a negative electrode terminal of the power supply means, and between each of the pair of inductors, between the inductor and the switching element and between the other inductor and the power supply means And a pair of capacitors to be connected.

  In the above-described invention, by providing the pair of inductors and capacitors, the boosting operation can be appropriately performed by the short circuit process.

The invention according to claim 7 is the invention according to any one of claims 1, 3, 4 to 6, wherein the rotating machine is a multi-phase rotating machine, and the setting means is the multi-phase rotating machine. The series connection body to be short-circuited is variably set based on a current parameter having a correlation with a current flowing through each of the phases.

  The more current that flows through the switching element, the higher the temperature of the switching element. In the above invention, in view of this point, by using a current parameter as the “parameter having a correlation with the temperature of the switching element”, it is possible to appropriately perform the processing related to the variable setting.

The invention according to claim 8 is the invention according to claim 7 , wherein the current parameter is an amount of current flowing through the switching element, and the setting means includes the switching element constituting the serial connection body. It is characterized by preferentially setting the short-circuit state for a small amount of flowing current.

  As the current flowing through the switching element increases, the temperature of the switching element tends to increase. In this regard, in the above invention, an excessive increase in temperature of the switching element can be suppressed by preferentially setting a short-circuited state with a small amount of current flowing through the switching element.

The invention according to claim 9 is the invention according to claim 7 , wherein the current parameter is one of a phase current of the multiphase rotating machine and a current flowing through each phase of the arm of the power conversion circuit, and the setting is performed. The means is characterized in that, in the series connection body, the corresponding one of the small quantities is preferentially placed in the short-circuit state.

  As the current flowing through the switching element increases, the temperature of the switching element tends to increase. And the electric current which flows through a switching element has a correlation with either said amount. In this regard, in the above invention, an excessive increase in the temperature of the switching element can be suppressed by preferentially short-circuiting any of the above-described amounts that are small.

  In addition, in the power conversion circuit, a circuit in which rectifying means is connected in parallel to the switching element is well known. In this case, the amount of any of the above is not necessarily only the current flowing through the switching element. However, it is particularly effective to use one of the above amounts under the situation where the switching element and the rectifying means are in thermal interference with each other.

A tenth aspect of the present invention is the invention according to any one of the first, third , and ninth aspects, wherein the setting means can change the series connection body that is in the short-circuit state based on temperature information of the switching element. It is characterized by setting.

  In the above invention, by using the temperature information of the switching element as the “parameter having a correlation with the temperature of the switching element”, it is possible to appropriately perform the processing related to the variable setting.

According to an eleventh aspect of the present invention, in the invention according to the tenth aspect , the setting means preferentially puts the switching element constituting the serial connection body having a low temperature into the short-circuit state. Features.

  In the above-described invention, it is possible to suppress an excessive increase in the temperature of the switching element by preferentially performing the process of setting the short circuit state that causes the temperature increase of the switching element on the low temperature of the switching element. it can.

According to the first aspect of the present invention, there is provided a high-potential-side switching element that is connected between the rotating machine and the power supply means, and that connects the rotating machine to the high-potential side, and a low-potential side that connects the rotating machine to the low-potential side. In a control device for a power conversion circuit that is applied to a power conversion circuit including a plurality of serially connected bodies with a switching element, and that performs a process of turning on the switching elements so that the serially connected body is in a short circuit state, the short circuit state And a setting means for variably setting the series connection body in accordance with a parameter having a correlation with the temperature of the switching element, wherein the setting means has a low temperature of the switching element constituting the series connection body. things and as the short-circuit state preferentially, when the temperature variation of the switching elements constituting the series connection is given below, all of the series Characterized by a connection body and short-circuit conditions.

  As the current flowing through the switching element increases, the temperature of the switching element tends to increase. And if the temperature dispersion | variation of a switching element is below predetermined, it will be thought that the temperature of the switching element which comprises the series connection body will become high compared with others by making a single series connection body into a short circuit state. In this respect, in the above-described invention, by setting all series-connected bodies in a short-circuit state under such circumstances, an excessive temperature rise of a specific switching element can be avoided and switching caused by the short-circuit state is established. The amount of increase in the temperature of the element can be minimized.

The invention of claim 1 wherein, in the invention according to any one of claims 1,3～6, wherein the power conversion circuit, the voltage of the power supply means by the series connection with the short-circuit state A parameter that has a correlation with the temperature of the switching element as to which one of the series connected bodies connected to the plurality of rotating machines is short-circuited. It is characterized in that it is variably set based on the above.

  In the above invention, based on a parameter having a correlation with the temperature of the switching element, it is possible to variably set which of the serially connected bodies connected to the plurality of rotating machines is in a short-circuit state, thereby suppressing the temperature rise of the switching element. be able to.

  Note that the power conversion circuit includes the following: “Equipped with an inductor, and when the series connection body is short-circuited, energy stored in the inductor is released when the short-circuit state of the series connection body is released. Boosting the voltage of the power feeding means using the phenomenon "or" the power feeding means using the phenomenon of having an inductor and generating an electromotive force in the inductor by releasing the short-circuit state of the series connection body " It is desirable that the voltage is boosted.

Claim 1 3 the described invention claimed in the invention of claim 1 2, wherein said setting means, a series connection to the short-circuited state, dispersed in the series connection being connected to each of the plurality of rotating machine It is characterized by making it.

  In the above invention, the temperature of the specific switching element is excessively increased by performing the process of setting the short circuit state, which is a process that causes the temperature increase of the switching element, to be dispersed in series connected bodies connected to a plurality of rotating machines. Can be avoided.

Low potential invention of claims 1 to 4, wherein, for connecting and connected between the rotating machine and the power supply means, a high potential side of the switching device for connecting the rotating machine to the high potential side of the rotating machine to the low potential side In a control device for a power conversion circuit, which is applied to a power conversion circuit including a plurality of series connection bodies with a switching element on the side, and performs a process of turning on the switching elements so that the series connection body is in a short circuit state, the short circuit The state is to turn on both the switching element on the high potential side and the switching element on the low potential side that constitute the same series connection body, and the power conversion circuit short-circuits the series connection body. The voltage of the power feeding means is boosted by setting the state, and the rotating machine is composed of a plurality, and an AC voltage is applied to the rotating machine by operating the power conversion circuit. When the rotating machine is driven by this, it is provided with setting means for dispersing and setting the series connection body in the short circuit state to the series connection body connected to each of the plurality of rotating machines. Features.

  Since the current that passes through the switching element on the high potential side and the switching element on the low potential side flows through the series connection body in the short-circuit state, the temperature is likely to rise. Here, when there are a plurality of rotating machines, there is a possibility that only the temperature of the switching elements constituting the series connection body connected to the specific rotating machine becomes excessively high. In the said invention, in view of this point, the temperature rise of a switching element can be suppressed by disperse | distributing the serial connection body which performs a short circuit process.

  Note that the power conversion circuit includes the following: “Equipped with an inductor, and when the series connection body is short-circuited, energy stored in the inductor is released when the short-circuit state of the series connection body is released. Boosting the voltage of the power feeding means using the phenomenon "or" the power feeding means using the phenomenon of having an inductor and generating an electromotive force in the inductor by releasing the short-circuit state of the series connection body " It is desirable that the voltage is boosted.

The invention of claim 1 5, wherein, in the invention according to any one of claims 1 2 to 14, the setting means, based on the inflow and outflow current between each of the rotating machine and the power conversion circuit It is variably set which of the plurality of rotating machines is connected to the series connection body to be short-circuited.

  The more current that flows through the switching element, the higher the temperature of the switching element. In the above invention, in view of this point, it is possible to suitably avoid that the temperature of a specific switching element becomes excessively high by using the inflow / outflow current as “a parameter having a correlation with the temperature of the switching element”. it can.

The invention according to claim 16 is the invention according to any one of claims 12 to 15 , wherein the setting means is temperature information constituting the series connection body connected to each of a plurality of rotating machines. The series connection body connected to which of the plurality of rotating machines is short-circuited based on the above.

  In the above-mentioned invention, it is preferable that the temperature of a specific series connection body becomes excessively high by making variable whether to short-circuit a series connection body connected to any of a plurality of rotating machines based on temperature information of a switching element. Can be avoided.

The invention according to claim 17 is the invention according to any one of claims 12 to 14 , wherein the power conversion circuit is connected between the switching element on the high potential side and a positive terminal of the power feeding means. And a pair of inductors composed of an inductor connected between the switching element on the low potential side and the negative terminal of the power feeding means, and each of the pair of inductors, and between the inductor and the switching element and the other inductor, An impedance network including a pair of capacitors connected between the power supply means, and the setting means includes an inflow / outflow current between the series connection body connected to each rotating machine and the impedance network. Based on this, it is variable whether the series connection body connected to which of the plurality of rotating machines is short-circuited Characterized in that it constant.

  The more current that flows through the switching element, the higher the temperature of the switching element. In the above invention, in view of this point, it is possible to suitably avoid an excessive increase in the temperature of a specific switching element by using the inflow / outflow current as a “parameter having a correlation with the temperature of the switching element”. it can.

The invention according to claim 18 is the serial connection according to any one of claims 12 to 14 , wherein the setting means is connected to any one of the plurality of rotating machines. It is characterized by periodically changing whether the body is short-circuited.

  In the said invention, the process which makes a short circuit state by changing periodically the process which makes the short circuit state which is the process which causes the temperature rise of a switching element to the serial connection body connected to which rotating machine is carried out. It is possible to avoid that the frequency to be made is biased to a serial connection body connected to a specific rotating machine. For this reason, it can avoid that the temperature of the serial connection body connected to a specific rotary machine rises too much.

The invention according to claim 19 is the voltage vector for applying a command voltage to each of the plurality of rotating machines in the short circuit state in the invention according to any one of claims 12 to 18. Is performed in a period in which all of the zero voltage vectors become.

  When at least one series connection body is in a short-circuit state, no voltage can be applied to any rotating machine. For this reason, when there is a rotating machine in which the voltage vector for applying the command voltage does not become a zero voltage vector when the processing for short-circuiting is performed, the voltage applied to this rotating machine is insufficient, and consequently the command voltage May not be able to be applied. In the above-mentioned invention, in view of this point, the process of setting the short-circuit state without interfering with the process of applying the command voltage to the rotating machine by performing the process of setting the short-circuit state in a period in which all voltage vectors are zero voltage vectors. It can be carried out.

According to a second aspect of the present invention, there is provided a high-potential-side switching element that is connected between the rotating machine and the power supply means, and that connects the rotating machine to the high-potential side, and a low-potential side that connects the rotating machine to the low-potential side. In a control device for a power conversion circuit, which is applied to a power conversion circuit including a plurality of serially connected bodies with a switching element, and performs a process of turning on the switching elements so that the serially connected body is in a short-circuit state. The circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state, and the rotating machine includes a plurality of the series connection body in the short-circuit state. voltage vector of the dispersed in series connection comprising a setting means for setting the processing to the short state, for applying a command voltage to at least one rotating machine to be connected to the respective The voltage vector for applying the command voltage is not a zero voltage vector in the plurality of rotating machines during the period in which the voltage is zero. In this case, the apparatus further includes means for compensating for a shortage caused by the short-circuit state with respect to the voltage applied to the rotating machine.
According to a third aspect of the present invention, there is provided a high-potential-side switching element that is connected between the rotating machine and the power supply means, and that connects the rotating machine to the high-potential side, and a low-potential side that connects the rotating machine to the low-potential side. In a control device for a power conversion circuit that is applied to a power conversion circuit including a plurality of serially connected bodies with a switching element, and that performs a process of turning on the switching elements so that the serially connected body is in a short circuit state, the short circuit state And a setting means for variably setting the series connection body according to a parameter having a correlation with the temperature of the switching element, and the power conversion circuit sets the voltage of the power supply means by setting the series connection body in a short-circuited state. The rotating machine includes a plurality of rotating machines, and the setting means determines which of the series connection bodies connected to the plurality of rotating machines is to be short-circuited. The short circuit state is variably set based on a parameter having a correlation with the temperature of the etching element, and the processing for setting the short circuit state is performed in a period in which a voltage vector for applying a command voltage to at least one rotating machine is a zero voltage vector. If the voltage vector for applying the command voltage does not become a zero voltage vector among the plurality of rotating machines during the short-circuited period, the rotating machine is applied to the rotating machine. The apparatus further comprises means for compensating for the shortage caused by the short circuit state with respect to the voltage to be transmitted.

  When at least one series connection body is in a short-circuit state, no voltage can be applied to any rotating machine. For this reason, when there is a rotating machine in which the voltage vector for applying the command voltage does not become the zero voltage vector when the short circuit processing is performed, the voltage applied to the rotating machine is insufficient, and the command voltage is There is a possibility that it cannot be applied. In the above invention, in view of this point, by providing means for compensating for the shortage caused by the short-circuit state with respect to the voltage applied to the rotating machine that is not the zero voltage vector, the short-circuit state is applied while applying the command voltage to the rotating machine. Can be performed.

(First embodiment)
Hereinafter, a first embodiment in which a power conversion circuit control device and a power conversion system according to the present invention are applied to a parallel hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows the system configuration of this embodiment. The illustrated motor generator 10 is a three-phase motor / generator. The motor generator 10 is connected to the high voltage battery 12 through a power conversion circuit including an inverter IV and an impedance network IN. The high voltage battery 12 is a secondary battery that applies a predetermined high voltage (for example, “288 V”).

  The inverter IV includes a serial connection body of switching elements Sup and Sun, a serial connection body of switching elements Svp and Svn, and a parallel connection body of a serial connection body of switching elements Swp and Swn. Here, the connection point of the switching element Sup and the switching element Sun is connected to the U phase of the motor generator 10, and the connection point of the switching element Svp and the switching element Svn is connected to the V phase of the motor generator 10. A connection point between the element Swp and the switching element Swn is connected to the W phase of the motor generator 10. Note that these switching elements Sup, Sun, Svp, Svn, Swp, Swn are constituted by insulated gate bipolar transistors (IGBTs), which are diodes Dup, Dun, Dvp, Dvn, Dwp, Dwn is connected.

  The impedance network IN includes an inductor 20 connected between the positive terminal side of the high voltage battery 12 and the high potential side input terminal of the inverter IV, and the negative terminal side of the high voltage battery 12 and the low potential side input terminal of the inverter IV. And an inductor 22 connected therebetween. Further, the impedance network IN includes a capacitor 24 that connects between the input terminal on the high potential side of the inverter IV and the inductor 20, and between the negative terminal and the inductor 22 of the high voltage battery 12, and between the positive terminal of the high voltage battery 12 and the inductor 20. A capacitor 26 that connects the input terminal on the low potential side of the inverter IV and the inductor 22 is provided.

  Between the positive terminal of the high-voltage battery 12 and the inductor 20, a diode 30 as a rectifier for backflow prevention and a switching element 32 for regeneration control are connected. In addition, a current sensor 34 that detects a U-phase current and a current sensor 36 that detects a V-phase current are provided on the electrical path between the inverter IV and the motor generator 10.

  The outputs of the sensors in the high voltage system such as the current sensors 34 and 36 are taken into the microcomputer (microcomputer 42) via the interface 40. The microcomputer 42 operates the switching elements Sup, Sun, Svp, Svn, Swp, Swn, and the switching element 32 based on the detection values of various sensors in the high-voltage system, the torque requested by the user, and the like. In other words, the inverter IV and the switching element 32 are operated. In particular, the microcomputer 42 operates the inverter IV by PWM processing so that the voltage applied to the motor generator 10 is a command voltage.

  Further, during this operation, the switching elements of both the upper arm and the lower arm are turned on, so that the series connection body of the switching elements Sup and Sun, the series connection body of the switching elements Svp and Svn, and the switching element Swp , Swn series connection body, a process of making a short circuit state (shoot-through: hereinafter short circuit process) is performed. This is a process for boosting the output voltage of the inverter IV. That is, the output voltage of the impedance network IN is made higher than the voltage of the high-voltage battery 12 by utilizing the phenomenon that a counter electromotive force is generated in the inductors 20 and 22 by canceling the short-circuit process after the short-circuit process is performed. Can do. Note that, in Patent Document 1, the switching period T and the short-circuit processing time of the series connection body are provided under the condition that the inductances of the inductors 20 and 22 are equal to each other and the capacitances of the capacitors 24 and 26 are equal to each other. There is an explanation that the output voltage is boosted to “Vo · T / (T−T0)” using the voltage Vo of the high voltage battery 12 at T0. Further, it is described that the AC voltage applied to the motor generator 10 using the modulation factor M is “M · Vo · T / {2 · (T−T0)}”.

  By performing the short-circuit process, the output voltage of the impedance network IN can be boosted, and as a result, the output voltage of the inverter IV can be boosted. However, the output voltage of the inverter IV becomes zero during the short circuit process. For this reason, even if the switching operation is performed according to the PWM process so that the voltage applied to the motor generator 10 is the command voltage, the actual output voltage of the inverter IV may not become the command voltage due to the short circuit process. Such a situation can be avoided by performing a short-circuit process in the zero voltage vector period. The zero voltage vector period is a V7 vector period in which all the switching elements Sup, Svp, Swp in the upper arm are in the on state, and a V0 vector period in which all the switching elements Sun, Svn, Swn in the lower arm are in the on state. That is. In other words, it is two vector periods of eight voltage vectors expressing that one of the upper arm and the lower arm is turned on for each phase. That is, since no voltage is output from the inverter IV in the zero voltage vector period, even if the short circuit process is performed using this period, the voltage applied to the motor generator 10 does not change.

  When short-circuit processing is performed during the zero voltage vector period, there are 19 variations shown in FIG. “9a to 9d” illustrated in FIG. 2 indicates a process of short-circuiting only the serial connection body of the U-phase switching elements Sup and Sun. Further, “10a to 10d” indicates a process of short-circuiting only the series connection body of the V-phase switching elements Svp and Svn. “11a to 11d” indicates a process of short-circuiting only the serial connection body of the W-phase switching elements Swp and Swn. “12a, 12b” indicates a process for shorting the U phase and the V phase, “13a, 13b” indicates a process for shorting the U phase and the W phase, and “14a, 14b” indicates the V phase and The process which short-circuits W phase is shown. Further, “15” indicates a process for short-circuiting all phases.

  By the way, when performing a short circuit process, the temperature of these switching elements rises because a comparatively large electric current flows into the switching element of the phase to be short-circuited. On the other hand, for example, during extremely low speed operation where the rotational speed of the motor generator 10 is equal to or lower than a predetermined value, there is a possibility that a large variation in the temperature of the switching element may occur without performing the short circuit process. For this reason, when a short circuit process is performed using a switching element whose temperature is already high under such circumstances, the temperature of the switching element may excessively increase, and as a result, the reliability thereof may decrease.

  Therefore, in the present embodiment, the series connection body that performs the short-circuit process is variably set according to a parameter that correlates with the temperature of the switching elements Sup, Sun, Svp, Svn, Swp, and Swn constituting the inverter IV. This will be described in detail below.

  In FIG. 3, the procedure of the short circuit process concerning this embodiment is shown. This process is repeatedly executed by the microcomputer 42 at a predetermined cycle, for example.

  In this series of processing, first, in step S10, phase currents Iu, Iv, Iw are acquired based on the detection values of the current sensors 34, 36. This process is a process for obtaining a parameter having a correlation with the temperature of the switching element of the inverter IV. That is, since the current flowing through the switching element is the main factor that raises the temperature of the switching element, the current flowing through the switching element is the above parameter. Since the phase currents Iu, Iv, and Iw have a correlation with the current flowing through the switching element, the phase currents Iu, Iv, and Iw are also the above parameters. Incidentally, the W-phase current Iw is calculated from the phase currents Iu and Iv detected by the current sensors 34 and 36 based on Kirchhoff's law.

  In the subsequent step S12, it is determined whether or not the phase current Iu has the smallest absolute value of the phase currents Iu, Iv, and Iw. This process is for determining whether or not the temperature of the U-phase switching element is considered to be the lowest. If it is determined that it is not the phase current Iu, it is determined in step S14 whether or not the phase current Iv is considered to have the minimum absolute value of the phase currents Iu, Iv, Iw. This process is for determining whether or not the temperature of the V-phase switching element is the lowest.

  It is determined by the processes in steps S12 and S14 which phase switching element is considered to have the lowest temperature, and a short circuit process is performed in the phase considered to be the lowest (steps S16, S18, and S20). In a succeeding step S22, it is determined whether or not it is a zero voltage vector period. And when it is judged that it is a zero voltage vector period, a short circuit process is performed in step S24. That is, in the zero voltage vector period, the short circuit process is performed for a period according to the voltage required as the output voltage of the impedance network IN. The short-circuiting period may be set longer as the required output voltage is higher.

  When the process of step S24 is completed, this series of processes is temporarily terminated.

  FIG. 4 shows an aspect of the short circuit process according to the present embodiment. Specifically, FIG. 4A shows changes in the command voltages Vu, Vv, and Vw, and FIG. 4B shows changes in the phase currents Iu, Iv, and Iw. FIG. 4C shows the transition of the operation mode of the switching element Sup, FIG. 4D shows the transition of the operation mode of the switching element Svp, and FIG. 4E shows the operation mode of the switching element Swp. 4 (f) shows the transition of the operation mode of the switching element Sun, FIG. 4 (g) shows the transition of the operation mode of the switching element Svn, and FIG. 4 (h) shows the switching mode. The transition of the operation mode of the element Swn is shown.

  As shown in the figure, it is possible to avoid an excessive increase in the temperature of a specific switching element by performing a short-circuit process on the phase currents Iu, Iv, and Iw that have a minimum absolute value.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The phase for performing the short circuit process is variably set according to a parameter having a correlation with the temperature of the switching element. Thereby, it can suppress that the temperature of a specific switching element rises too much.

  (2) Short-circuiting was performed on the phase where the absolute values of the phase currents Iu, Iv, and Iw were minimum. Here, when the phase currents Iu, Iv, and Iw are used, the short-circuiting process is not necessarily performed by selecting the phase that minimizes the current flowing through the switching element. This is because the phase currents Iu, Iv, Iw are composed of both the current flowing through the diodes Dup, Dun, Dvp, Dvn, Dwp, Dwn and the current flowing through the switching elements Sup, Sun, Svp, Svn, Swp, Swn. It is. For this reason, this embodiment which performs a short circuit process based on phase current Iu, Iv, Iw is especially effective when these thermal interferences are large, such as when these switching elements and diodes are integrally formed.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 5 shows a system configuration of the present embodiment. In FIG. 5, members corresponding to those shown in FIG. 1 are given the same reference numerals for convenience. As shown in the figure, in this embodiment, the switching elements Sup, Sun, Svp, Svn, Swp, Swn output a sense terminal ST that outputs a minute current having a correlation with a current flowing through its input / output terminals (collector and emitter). It has. Then, the microcomputer 42 performs short circuit processing based on the output current of the sense terminal ST.

  FIG. 6 shows the procedure of the short-circuit process according to this embodiment. This process is repeatedly executed by the microcomputer 42 at a predetermined cycle, for example.

  In this series of processing, first, in step S30, output currents (sense currents Iup, Iun, Ivp, Ivn, Iwp, Iwn) of the respective sense terminals ST of the switching elements Sup, Sun, Svp, Svn, Swp, Swn are acquired. To do. This process is a process for obtaining a parameter having a correlation with the temperature of the switching element. In the subsequent step S32, the larger of the U-phase sense currents Iup and Iun is set as the sense current Ius, the larger of the V-phase sense currents Ivp and Ivn is set as the sense current Ivs, and the W-phase sense current Iwp, The larger of Iwn is defined as a sense current Iws. This process is performed in view of the fact that current flows only in one of the upper arm and the lower arm in each phase.

  In a succeeding step S34, it is determined whether or not the sense current Ius has the minimum sense current Ius, Ivs, Iws. This process is for determining whether or not the temperature of the U-phase switching element is considered to be the lowest. If it is determined that it is not the sense current Ius, it is determined in step 36 whether or not the sense current Ivs, Ivs, Iws has the minimum value. This process is for determining whether or not the temperature of the V-phase switching element is considered to be the lowest.

  It is determined by the processing in steps S34 and S36 which phase switching element is considered to have the lowest temperature, and short-circuit processing is performed in the phase considered to be the lowest (steps S38, S40, and S42). In subsequent steps S44 and S46, processing similar to the processing in steps S22 and S24 of FIG. 3 is performed.

  According to the present embodiment described above, the following effects can be obtained in addition to the effect (1) of the first embodiment.

  (3) Short circuit processing was performed based on the sense currents Ius, Ivs, and Iws. Thereby, a short circuit process can be performed based on the parameter which has a direct correlation with the temperature rise of a switching element.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 7 shows a cooling device for the inverter IV according to the present embodiment. As shown in the figure, in this embodiment, each of the switching elements Sup, Sun, Svp, Svn, Swp, Swn, together with the corresponding diode Dup, Dun, Dvp, Dvn, Dwp, Dwn, and the temperature sensitive diode SD, It is packaged in a card PC and accommodated in a cooling device. Here, the temperature sensing diode SD senses the temperature of the switching elements Sup, Sun, Svp, Svn, Swp, Swn. A cooling fluid such as cooling water flows in the cooling device, thereby cooling the power card PC.

  Here, in the present embodiment, the short circuit process is performed based on the temperature sensed by the temperature sensitive diode SD. This will be described in detail below.

  FIG. 8 shows a procedure of short-circuit processing according to the present embodiment. This process is repeatedly executed by the microcomputer 42, for example, at a predetermined cycle.

  In this series of processes, first, in step S50, temperatures Tup, Tun, Tvp, Tvn, Twp, and Twn sensed by the respective temperature sensitive diodes SD of the switching elements Sup, Sun, Svp, Svn, Swp, and Swn are acquired. This process is a process for obtaining a parameter having a correlation with the temperature of the switching element. In the subsequent step S52, the higher one of the temperatures Tup, Tun of the U-phase switching elements Sup, Sun is set as the temperature Tu, and the higher one of the temperatures Tvp, Tvn of the V-phase switching elements Svp, Svn is set as the temperature Tv. The higher one of the temperatures Twp and Twn of the W-phase switching elements Swp and Swn is defined as a temperature Tw. This processing is performed in view of the fact that the temperature of either one of the upper arm and the lower arm is particularly high because current flows only to one of the upper arm and the lower arm in each phase.

  In a succeeding step S54, it is determined whether or not the temperature Tu has the lowest temperature Tu, Tv, Tw. In step 56, it is determined whether or not the temperature Tv has the lowest temperature Tu, Tv, Tw. By the processing of these steps S54 and S56, it is determined which temperature of the switching element of which phase is the lowest, and the short circuit processing is performed in the lowest phase (steps S58, S60 and S62). In steps S64 and S66, the processes in steps S22 and S24 in FIG. 3 are performed.

  According to the present embodiment described above, the following effects can be obtained in addition to the effect (1) of the first embodiment.

  (4) A short circuit process was performed based on the temperatures Tu, Tv, and Tw of the switching elements. Thereby, the process concerning the variable setting of a short circuit process can be performed appropriately.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the third embodiment.

  FIG. 9 shows a procedure of the short-circuit process according to the present embodiment. This process is repeatedly executed by the microcomputer 42, for example, at a predetermined cycle.

  In this series of processes, the same processes as in steps S50 and S52 of FIG. 8 are performed in steps S70 and S72. On the other hand, in step S74, it is determined whether or not the difference between the highest value and the lowest value among the temperatures Tu, Tv, and Tw is equal to or less than a specified value α. This process is for determining whether or not it is desirable to perform the short circuit process in all phases since there is no phase in which the temperature variation of the switching elements is small and it is particularly effective to perform the short circuit process. The prescribed value α is set to a value that is assumed to cause the temperature of the switching element in that phase to be excessively high compared to the other when the short-circuit process is performed in a specific phase because the temperature variation is small. If it is equal to or less than the specified value α, it is determined in step S78 that short-circuit processing is performed for all phases. This means that the pattern “15” in FIG. 2 has been selected.

  On the other hand, if it is greater than the prescribed value α, it is determined in step S76 whether or not the difference between the intermediate values for the lowest value among the temperatures Tu, Tv, and Tw is less than or equal to the prescribed value β. This process is for determining whether or not it is desirable to perform the short-circuit process in these two phases because the difference between the intermediate value and the minimum value is small. And when it is judged that it is below regulation value (beta), in step S80, it determines to perform a short circuit process in the phase from which temperature becomes the minimum value, and the phase from which it becomes an intermediate value. This means that one of the patterns “12a, 12b, 13a, 13b, 14a, 14b” in FIG. 2 has been selected. On the other hand, if it is determined that the value exceeds the specified value β, it is determined in step S82 that the short-circuit process is performed only in the phase where the temperature is the lowest value. In addition, when the process of step S78, S80, S82 is completed, this series of processes is once complete | finished.

  According to the present embodiment described above, the following effects can be obtained in addition to the effects of the third embodiment.

  (5) The number of phases to be short-circuited is variable according to the temperature variation of the switching elements. Thereby, the dispersion | variation in the temperature of a switching element can be suppressed suitably.

  (6) When the variation in the temperature of the switching element is equal to or less than a predetermined value, a short circuit process was performed for all phases. Thereby, the amount of increase in the temperature of the switching element due to the short circuit state can be minimized.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In the present embodiment, the present invention is applied to a power conversion circuit of a parallel series hybrid vehicle. FIG. 10 shows a configuration of the power conversion circuit according to the present embodiment. In FIG. 10, members corresponding to those shown in FIG. 1 are given the same reference numerals for convenience.

  As shown in the drawing, in the present embodiment, in order to include two three-phase rotating machines of the first motor generator 10 and the second motor generator 10, separate inverters IV1 and IV2 are provided corresponding to these three-phase rotating machines. . The input terminals of the inverters IV1 and IV2 are connected to the same impedance network IN.

  As described above, when both the inverters IV1 and IV2 are connected to the same impedance network IN, the output voltage of the impedance network IN can be boosted by performing a short circuit process on either one of them. However, in this case, when the short circuit process is performed on one of the inverters IV1 and IV2, the other output voltage is also zero. For this reason, when one short-circuit process is performed in a period other than the zero voltage vector period on the other side, the other output voltage may deviate from the command voltage.

  Therefore, in the present embodiment, both carriers of the inverters IV1 and IV2 are synchronized with the same period. Then, one of the inverters IV1 and IV2 performs a short circuit process, and the one inverter is periodically switched. In FIG. 11, the aspect of the short circuit process concerning this embodiment is shown. Specifically, FIGS. 11 (a1) and 11 (a2) show the zero voltage vector period on the inverter IV1 side, and FIGS. 11 (b1) and 11 (b2) show the presence / absence of short-circuit processing on the inverter IV1 side. 11 (c1) and FIG. 11 (c2) show the zero voltage vector period on the inverter IV2 side, and FIG. 11 (d1) and FIG. 11 (d2) show the presence or absence of short-circuit processing on the inverter IV2 side. . In particular, FIG. 11 (a1), FIG. 11 (b1), FIG. 11 (c1), and FIG. 11 (d1) show the case where the short circuit process is alternately performed once on the inverter IV1 side and the inverter IV2 side. Yes. FIG. 11 (a2), FIG. 11 (b2), FIG. 11 (c2), and FIG. 11 (d2) show the case where the short circuit process is alternately performed twice on the inverter IV1 side and the inverter IV2 side. Yes.

  According to such processing, it is possible to avoid that the temperature of one of the switching elements of the inverter IV1 and the inverter IV2 becomes excessively high, and accordingly, it is possible to suitably suppress the temperature variation of all these switching elements. be able to. In addition, when performing the short circuit process on either the inverter IV1 side or the inverter IV2 side, the short circuit process may be performed on all phases constituting these, but the methods exemplified in the first to fourth embodiments. Thus, it may be determined in which phase the short-circuit treatment is performed.

  According to this embodiment described above, the following effects can be obtained in addition to the effects of the first embodiment.

  (7) The series connection body which carries out a short circuit process was disperse | distributed to six series connection bodies which comprise inverter IV1, IV2. Thereby, it can avoid that the temperature of a specific series connection body rises excessively.

  (8) Whether the short circuit processing is performed on the inverter IV1 side or the inverter IV2 side is periodically changed. As a result, it is possible to avoid an excessive rise in the temperature of either the inverter IV1 or the inverter IV2, and thus it is possible to suppress variations in the temperature of the switching elements of the inverters IV1 and IV2.

  (9) Short circuit processing was performed in a period in which the voltage vector was a zero voltage vector in both inverters IV1 and IV2. Thereby, a short circuit process can be performed without preventing the process of applying the command voltage to both the first motor generator 10a and the second motor generator 10b.

  (10) The carriers on the inverter IV1 side and the inverter IV2 side are synchronized with each other in the same cycle. Thereby, both these zero voltage vector periods can be synchronized, and the process of said (9) can be performed appropriately by extension.

(Sixth embodiment)
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the fifth embodiment.

  FIG. 12 shows a short-circuit processing aspect according to this embodiment. Specifically, FIG. 12A shows the transition of the command voltage on the first motor generator 10a side, and FIG. 12B shows the transition of the command voltage on the second motor generator 10b side. FIGS. 12C to 12H show the transition of the ON / OFF state of the switching element of the inverter IV2 that applies a voltage to the second motor generator 10b.

  As shown in the figure, in the present embodiment, a short circuit process is performed for each of the inverters IV1 and IV2 in a zero voltage vector period corresponding to a carrier peak. In this case, when the voltage vector for the other is not the zero voltage vector in the zero voltage vector period corresponding to the carrier peak for one of the inverters IV1 and IV2, the other output voltage does not become the command voltage.

  In order to cope with such a situation, in the present embodiment, processing for compensating for the shortage of voltage due to the short-circuit processing is performed in the zero voltage vector period corresponding to the valley of the carrier. FIG. 12 shows an example in which the voltage vector on the second motor generator 10b side is not the zero voltage vector when the short circuit process is performed on the first motor generator 10a side. In this case, in the zero voltage vector period corresponding to the carrier valley on the second motor generator 10b side, the PWM processing is changed to the voltage vector in the short-circuit processing period instead of the zero voltage vector.

  In FIG. 12, for the sake of convenience, the zero voltage vector period corresponding to the carrier valley on the second motor generator 10b side is described so as to coincide with the short-circuit processing period. Not exclusively. In this case, it is desirable to switch to the zero voltage vector, which is the original voltage vector required by the PWM processing, after the short-circuit processing period has elapsed. By the way, in order to compensate for the shortage of voltage in the zero voltage vector period corresponding to one trough of the carrier, the short circuit processing period must be within the zero voltage vector period which is the maximum period of the other voltage compensation period. It is desirable to limit to

  According to the present embodiment described above, in addition to the effect (7) of the previous fifth embodiment, the following effect can be obtained.

  (11) When short circuit processing is performed on one of the inverter IV1 side and the inverter IV2 side and the voltage vector period on the other side is not the zero voltage vector period, the shortage of voltage due to the short circuit processing is compensated. Thereby, it is possible to perform the short circuit process while applying the command voltage to both the first motor generator 10a and the second motor generator 10b.

(Seventh embodiment)
Hereinafter, the seventh embodiment will be described with reference to the drawings with a focus on differences from the fifth embodiment.

  FIG. 13 shows a configuration of the power conversion circuit according to the present embodiment. In FIG. 13, members corresponding to those shown in FIG. 10 are given the same reference numerals for convenience.

  As shown in the figure, the present embodiment includes current sensors 50 and 52 that detect inflow and outflow currents I1 and I2 between the impedance network IN and the inverters IV1 and IV2, respectively. Based on these, it is determined whether the short circuit process is performed on the inverter IV1 side or the short circuit process is performed on the inverter IV2 side. That is, as shown in the lower left side of the figure, if the absolute value of the inflow / outflow current I1 is smaller than the absolute value of the current I2 (step S90: YES), short circuit processing is performed on the inverter IV1 side (step S92). If not (step S90: NO), short circuit processing is performed on the inverter IV2 side (step S94).

  In addition, when performing the short circuit process on either the inverter IV1 side or the inverter IV2 side, the short circuit process may be performed on all phases constituting these, but the methods exemplified in the first to fourth embodiments. Thus, it may be determined in which phase the short-circuit treatment is performed.

  According to the present embodiment described above, in addition to the effect (7) of the previous fifth embodiment, the following effect can be obtained.

  (12) Based on the inflow / outflow current between the impedance network IN and the inverters IV1 and IV2, it is determined which of the inverter IV1 side and the inverter IV2 side performs the short-circuit process. Thereby, it can avoid suitably that the temperature of the switching element which comprises any one of inverter IV1 and IV2 rises excessively.

(Eighth embodiment)
Hereinafter, the eighth embodiment will be described with reference to the drawings with a focus on differences from the fifth embodiment.

  FIG. 14 shows a cooling device for the inverter IV according to the present embodiment. As shown in the figure, in the present embodiment, each of the switching elements Sup, Sun, Svp, Svn, Swp, Swn of each inverter IV1, IV2 has a corresponding diode Dup, Dun, Dvp, Dvn, Dwp, Dwn and a sense. Along with the warm diode SD, it is packaged in a power card PC and accommodated in a cooling device. And cooling fluid, such as cooling water, flows in a cooling device, for example, and power card PC is cooled by this.

  Here, in the present embodiment, the short circuit process is performed according to the temperature sensed by the temperature sensitive diode SD. This will be described in detail below.

  FIG. 15 shows the procedure of the short-circuit process according to the present embodiment. This process is repeatedly executed by the microcomputer 42, for example, at a predetermined cycle.

  In this series of processes, first, in step S100, an average value Tav1 of the temperatures of the switching elements Sup, Sun, Svp, Svn, Swp, Swn sensed by the temperature sensitive diode SD on the inverter IV1 side is calculated. In subsequent step S102, an average value Tav2 of the temperatures of the switching elements Sup, Sun, Svp, Svn, Swp, Swn sensed by the temperature sensitive diode SD on the inverter IV2 side is calculated. In a succeeding step S104, it is determined whether or not the average value Tav1 is equal to or less than the average value Tav2. And when it is judged that it is below average value Tav2, a short circuit process is performed by the inverter IV1 side in step S106. On the other hand, when it is determined in step S104 that the average value Tav2 is not less than or equal to, in step S108, a short circuit process is performed on the inverter IV2 side.

  In addition, when performing the short circuit process on either the inverter IV1 side or the inverter IV2 side, the short circuit process may be performed on all phases constituting these, but the methods exemplified in the first to fourth embodiments. Thus, it may be determined in which phase the short-circuit treatment is performed.

  According to the present embodiment described above, in addition to the effect (7) of the previous fifth embodiment, the following effect can be obtained.

  (13) Based on the average values Tav1 and Tav2, it is variably set whether the short circuit processing is performed on the inverter IV1 side or the inverter IV2 side. Thereby, it can avoid suitably that the temperature of a specific switching element becomes high too much.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In the first embodiment, the phase in which the phase currents Iu, Iv, and Iw are minimized is short-circuited in the zero voltage vector period, but the present invention is not limited to this. For example, when the difference between the smallest one of the phase currents Iu, Iv, and Iw and the second smallest current is equal to or less than a predetermined value, these two phases may be short-circuited in the zero voltage vector period. Further, for example, when the difference between the maximum value and the minimum value of the phase currents Iu, Iv, and Iw is equal to or less than a predetermined value, short-circuit processing may be performed for all phases in the zero voltage vector period.

  The process for periodically changing which of the inverter IV1 side and the inverter IV2 side performs the short-circuit process is not limited to that exemplified in the previous fifth embodiment (FIG. 11). For example, the short circuit process may be performed three times on each of the inverter IV1 side and the inverter IV2 side.

  -You may use combining the process illustrated in the said 1st Embodiment or the said 2nd Embodiment, and the process illustrated in the said 3rd Embodiment. That is, the phase current as a parameter having a correlation with the temperature of the switching element and the current flowing through the switching element are considered parameters for feedforward control of the temperature of the switching element, while the temperature of the switching element is used for feedback control. Parameter (feedback control amount). For this reason, when the temperature variation by feedforward control becomes remarkable, if the process which applies feedback correction by incorporating feedback control temporarily is performed, the excessive temperature rise of a specific switching element will be suppressed more appropriately. be able to.

  In the fifth embodiment, the inverters IV1 and IV2 have the PWM processing carriers in the same cycle and synchronized with each other. However, the present invention is not limited to this. For example, an integer multiple of the frequency of one carrier may be used as the other carrier. In this case, when both become zero voltage vectors, short circuit processing may be performed by one of the inverters IV1 and IV2.

  In the sixth embodiment, the short circuit process is alternately performed once on the inverter IV1 side and on the inverter IV2 side, but the present invention is not limited to this. For example, the short-circuit process may be alternately performed twice on the inverter IV1 side and the inverter IV2 side.

  In the eighth embodiment, the average value of the temperatures of the switching elements Sup, Sun, Svp, Svn, Swp, Swn of the inverter IV1 and the temperature of the switching elements Sup, Sun, Svp, Svn, Swp, Swn of the inverter IV2 Based on the average value, it is determined which of the inverter IV1 side and the inverter IV2 side performs the short-circuit processing, but the present invention is not limited to this. For example, the higher value Tu among the temperatures of the switching elements Sup and Sun, the higher value Tv among the temperatures of the switching elements Svp and Svn, and the higher value of the temperatures of the switching elements Swp and Swn. The minimum value of Tw may be compared with each other, and the short circuit may be performed on the inverter side having the lower one. In this case, it is particularly effective to perform the short-circuit process in a phase corresponding to the minimum value.

  -It is not restricted to what performs a short circuit process in any one of the inverter IV1 side and the inverter IV2 side. For example, in the setting in which both carriers are synchronized with each other in the same cycle as in the fifth embodiment, each of the inverters IV1 and IV2 may be short-circuited in a phase that minimizes the phase current.

  As a technique for distributing the short-circuit process to the series connection body of the switching elements constituting the inverter IV1 and the series connection body of the switching elements constituting the inverter IV2, the methods exemplified in the above embodiments and their modifications are used. Not exclusively. For example, which of all the serially connected bodies of the inverters IV1 and IV2 performs the short-circuit process may be variably set by the method described in the first to fourth embodiments.

  The current parameter correlated with the current flowing through each phase of the multiphase rotating machine is not limited to the phase current or the current flowing through the switching elements Sup, Sun, Svp, Svn, Swp, and Swn. For example, as shown in FIG. 16, it may be a current flowing through each arm. FIG. 16 illustrates a method of detecting an arm current as a voltage drop amount of the shunt resistor R provided in the U phase and the V phase in the lower arm.

  In the seventh embodiment, based on the magnitude relationship between the inflow / outflow current I1 between the impedance network IN and the inverter IV1 and the inflow / outflow current IV2 between the inverter IV2, the inverter IV1 side and the inverter IV2 side Which of the short-circuit processing is determined is not limited to this. For example, as shown in FIG. 17, it may be determined based on the inflow / outflow current of the inverter IV1 and the inflow / outflow current of the inverter IV2 which one of the inverter IV1 side and the inverter IV2 side performs the short-circuit processing. In FIG. 17, the W-phase current is calculated from the U-phase and V-phase currents of the inverters IV1 and IV2, and the minimum values of the respective phase currents are compared with each other, so that the inverter IV1 side and the inverter IV2 side An example of determining which of the short circuit processing is performed is shown. That is, when the minimum value on the inverter IV1 side is smaller (step S110: YES), the short circuit processing is performed on the inverter IV1 side (step S112). Otherwise (step S110: NO), the inverter IV2 side is performed. Then, short circuit processing is performed (step S114).

  As shown in FIG. 18, the short-circuit process may be performed with a larger modulation rate in the setting in which the carrier is synchronized with the same period as in the fifth embodiment. That is, in such a setting, the zero voltage vector period is included in the lower one with the higher modulation rate. For this reason, by performing the short-circuit process in the zero voltage vector period with the higher modulation rate, the voltage control with the lower modulation rate is not hindered. At this time, it is desirable to use the method or the like exemplified in each of the above-described embodiments to determine which phase is subjected to the short-circuit treatment.

  Further, even when the carrier is different between the inverter IV1 side and the inverter IV2 side, there is a merit in performing the short-circuit process with the larger modulation rate. Accordingly, the compensation processing illustrated in the sixth embodiment is performed on the side where the modulation rate is low. However, the lower the modulation rate, the longer the zero voltage vector period. Therefore, in one zero voltage vector period. Compensation processing can be performed reliably.

  The temperature information of the switching elements Sup, Sun, Svp, Svn, Swp, Swn is not limited to the detected value of the means that directly detects the temperature itself. For example, as shown in FIG. 19, in the configuration in which the inverter IV1 and the inverter IV2 are cooled by independent cooling devices, the temperatures T1 and T2 of the temperature sensitive diode SD that senses the temperature of each cooling fluid are used as temperature information. May be. FIG. 19 shows a case where the short circuit process is performed on the inverter IV1 side when the temperature T1 of the cooling fluid on the inverter IV1 side is lower, and the short circuit process is performed on the inverter IV2 side otherwise.

  The impedance network IN is not limited to that exemplified in the above embodiment. For example, FIG. Of “Z-Source Inverter for Fuel Cell Vehicles submitted to Oak Ridge National Laboratory Engineering Science and Technology Division Power Electrics Electric Machinery Research Center August 31 2005”. As described in 3.4, a configuration in which some diodes and capacitors are additionally connected to the one shown in FIG. 1 may be used.

  The process for applying the command voltage to the rotating machine is not limited to the PWM process for modulating the carrier based on the command voltage. For example, so-called space vector modulation processing exemplified in JP-A-10-4696 may be used.

  -The rotating machine is not limited to a three-phase rotating machine. For example, a single-phase rotating machine may be used. Even in this case, in a power conversion circuit including a plurality of switching elements connecting the rotating machine to the high potential side of the impedance network and switching elements connecting to the low potential side, the temperature information of the switching elements It is effective to variably set the series connection body that performs short-circuit processing according to the above. Incidentally, the configuration in which a plurality of devices are connected in parallel is a configuration that is used to increase the drivable current while suppressing the element size of a single switching element.

  ・ Hybrid vehicles are not limited to parallel hybrid vehicles and parallel series hybrid vehicles. For example, a series hybrid vehicle may be used. Further, the present invention may be applied not only to a hybrid vehicle but also to a power conversion circuit of an electric vehicle, for example. Furthermore, the power conversion circuit is not limited to one or two rotating machines connected, and may be three or more connected. The power supply means is not limited to a secondary battery, and may be a primary battery, for example.

1 is a system configuration diagram according to a first embodiment. FIG. The figure which shows the switching state in which a short circuit process is accept | permitted. The flowchart which shows the procedure of the short circuit process concerning the said embodiment. The time chart which shows the short circuit process aspect concerning the embodiment. The system block diagram concerning 2nd Embodiment. The flowchart which shows the procedure of the short circuit process concerning the embodiment. The top view which shows the cooling structure of the inverter concerning 3rd Embodiment. The flowchart which shows the procedure of the short circuit process concerning the embodiment. The flowchart which shows the procedure of the short circuit process concerning 4th Embodiment. The circuit diagram which shows the circuit structure of the power converter circuit concerning 5th Embodiment. The time chart which shows the aspect of the short circuit process concerning the embodiment. The time chart which shows the aspect of the short circuit process concerning 6th Embodiment. The circuit diagram which shows the circuit structure of the power converter circuit concerning 7th Embodiment. The top view which shows the cooling structure of the inverter concerning 8th Embodiment. The flowchart which shows the procedure of the short circuit process concerning the embodiment. The system block diagram concerning the modification of 1st Embodiment. The circuit diagram which shows the circuit structure of the power converter circuit concerning the modification of 7th Embodiment. The time chart which shows the aspect of the short circuit process concerning the modification of 5th Embodiment. The top view which shows the cooling structure of the inverter concerning the modification of 8th Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 10a, 10b ... Motor generator (one embodiment of rotating machine), 12 ... High voltage battery (one embodiment of power supply means), IV, IV1, IV2 ... Inverter, IN ... Impedance network, Sup, Sun, Svp, Svn , Swp, Swn... Switching element.

Claims (19)

A series-connected body of a high-potential side switching element that is connected between the rotating machine and the power supply means and that connects the rotating machine to the high-potential side and a low-potential side switching element that connects the rotating machine to the low-potential side In a control device for a power conversion circuit that is applied to a power conversion circuit that includes a plurality of the switching elements, and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state.
A setting means for variably setting the series connection body in the short-circuit state according to a parameter having a correlation with the temperature of the switching element,
The setting means preferentially sets the switching element constituting the series connection body in which the temperature of the switching element is low as the short-circuit state, and variation in temperature of the switching element constituting the series connection body is equal to or less than a predetermined value. If this is the case, the control device for the power conversion circuit is characterized in that all series-connected bodies are in a short-circuit state. A series-connected body of a high-potential side switching element that is connected between the rotating machine and the power supply means and that connects the rotating machine to the high-potential side and a low-potential side switching element that connects the rotating machine to the low-potential side In a control device for a power conversion circuit that is applied to a power conversion circuit that includes a plurality of the switching elements, and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state.
The power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state,
The rotating machine comprises a plurality of
The series connection body to be in the short-circuit state is provided with setting means for dispersing and setting the series connection body connected to each of the plurality of rotating machines,
The processing for setting the short circuit state is performed in a period in which a voltage vector for applying a command voltage to at least one rotating machine is a zero voltage vector,
When there is a voltage vector for applying the command voltage that does not become a zero voltage vector in the plurality of rotating machines during the short circuit state, the voltage applied to the rotating machine is A control device for a power conversion circuit, further comprising means for compensating for a shortage caused by a short-circuit state. A series-connected body of a high-potential side switching element that is connected between the rotating machine and the power supply means and that connects the rotating machine to the high-potential side and a low-potential side switching element that connects the rotating machine to the low-potential side In a control device for a power conversion circuit that is applied to a power conversion circuit that includes a plurality of the switching elements, and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state.
A setting means for variably setting the series connection body in the short-circuit state according to a parameter having a correlation with the temperature of the switching element,
The power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state,
The rotating machine comprises a plurality of
The setting means variably sets which of the series connection bodies connected to the plurality of rotating machines is short-circuited based on a parameter having a correlation with the temperature of the switching element,
The processing for setting the short circuit state is performed in a period in which a voltage vector for applying a command voltage to at least one rotating machine is a zero voltage vector,
When there is a voltage vector for applying the command voltage that does not become a zero voltage vector in the plurality of rotating machines during the short circuit state, the voltage applied to the rotating machine is A control device for a power conversion circuit, further comprising means for compensating for a shortage caused by a short-circuit state. A series-connected body of a high-potential side switching element that is connected between the rotating machine and the power supply means and that connects the rotating machine to the high-potential side and a low-potential side switching element that connects the rotating machine to the low-potential side In a control device for a power conversion circuit that is applied to a power conversion circuit that includes a plurality of the switching elements, and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state.
The short-circuit state is to turn on both the high-potential side switching element and the low-potential side switching element constituting the same series connection body,
The power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state,
When the rotating machine is driven by applying an AC voltage to the rotating machine by operating the power conversion circuit, the series connection body to be short-circuited is a parameter having a correlation with the temperature of the switching element. A control device for a power conversion circuit, comprising setting means for variably setting in response. The power conversion circuit, a control device for a power conversion circuit according to claim 1 or 3, wherein said is to boost the voltage of the power supply means by a series connection with the short-circuit state. The power conversion circuit includes a pair of an inductor connected between the switching element on the high potential side and the positive terminal of the power feeding means, and an inductor connected between the switching element on the low potential side and the negative terminal of the power feeding means. and inductors, each of said pair of inductors, claim 4, characterized in that it comprises a pair of capacitors connected between the between between the inductor and the switching element and the other inductor and the power feeding means or 5. The control device for the power conversion circuit according to 5 . The rotating machine is a multi-phase rotating machine;
The setting means, according to claim, characterized in that for variably setting a series connection to the short-circuited state based on the current parameter correlated with the current flowing through each phase of the polyphase rotating machine 1,3,4～6 The control apparatus of the power converter circuit of any one of these. The current parameter is an amount of current flowing through the switching element,
8. The power conversion circuit according to claim 7 , wherein the setting means preferentially sets the short circuit state of the series connection body that has a small amount of current flowing through the switching element constituting the serial connection body. Control device. The current parameter is one of a phase current of the multiphase rotating machine and a current flowing in each phase of the arm of the power conversion circuit,
8. The control apparatus for a power conversion circuit according to claim 7 , wherein the setting means preferentially sets the corresponding one of the series connected bodies in a small amount to the short circuit state. The setting means, based on temperature information of the switching device, the power conversion circuit according to any one of claims 1,3～9, characterized in that for variably setting a series connection to the short-circuit state Control device. 11. The control apparatus for a power conversion circuit according to claim 10 , wherein the setting means preferentially sets a switching element constituting the series connection body having a low temperature in the short circuit state. The power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state,
The rotating machine comprises a plurality of
The setting means, according to claim, characterized in that variably set based or shorting any of the series connection connected to the plurality of rotary machine parameter correlated with the temperature of the switching elements 1 The control apparatus of the power converter circuit of any one of -6 . The setting means, the series connection to the short-circuited state, the controller of the power conversion circuit of claim 1 2, wherein the dispersing said series connection being connected to each of the plurality of rotating machine . A series-connected body of a high-potential side switching element that is connected between the rotating machine and the power supply means and that connects the rotating machine to the high-potential side and a low-potential side switching element that connects the rotating machine to the low-potential side In a control device for a power conversion circuit that is applied to a power conversion circuit that includes a plurality of the switching elements, and performs a process of turning on the switching element so as to put the series connection body in a short-circuit state.
The short-circuit state is to turn on both the high-potential side switching element and the low-potential side switching element constituting the same series connection body,
The power conversion circuit boosts the voltage of the power feeding means by setting the series connection body in a short-circuit state,
The rotating machine comprises a plurality of
When the rotating machine is driven by applying an AC voltage to the rotating machine by operating the power conversion circuit, the series connection body to be short-circuited is connected to each of the plurality of rotating machines. A control device for a power conversion circuit, comprising setting means for setting by dispersing in the series connection body. The setting means variably sets which one of the plurality of rotating machines is short-circuited based on an inflow / outflow current between the power conversion circuit and each of the rotating machines. The control device for a power conversion circuit according to any one of claims 12 to 14 . The setting means variably sets which of the plurality of rotating machines to which the series connection body is short-circuited based on temperature information constituting the series connection body connected to each of the plurality of rotating machines. The control device for a power conversion circuit according to any one of claims 12 to 15 , wherein the control device is a power conversion circuit control device. The power conversion circuit includes a pair of an inductor connected between the switching element on the high potential side and the positive terminal of the power feeding means, and an inductor connected between the switching element on the low potential side and the negative terminal of the power feeding means. Each of the pair of inductors and an impedance network comprising a pair of capacitors connected between the inductor and the switching element and between the other inductor and the power feeding means,
The setting means can change which of the plurality of rotating machines is short-circuited based on an inflow / outflow current between the series connection body connected to each rotating machine and the impedance network. It sets, The control apparatus of the power converter circuit of any one of Claims 12-14 characterized by the above-mentioned. The said setting means changes periodically whether the said series connection body connected to which rotary machine of these several rotary machines is short-circuited, The any one of Claims 14-14 characterized by the above-mentioned. The control apparatus of the power conversion circuit as described in the item. Process to the short state, claim 1 2-18, characterized in that all the voltage vectors for applying each command voltage to said plurality of rotary machines are intended to be made in a period in which the zero voltage vector The control apparatus of the power converter circuit of any one of these.

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