JP2015023709A - Power conversion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve continuous traveling of a railway vehicle because power conversion can be continued by a power conversion apparatus even when a temperature of any one of arms functioned as first arms becomes higher than an upper limit temperature allowing use of the arm on management or a failure occurs in the arm.SOLUTION: A power conversion apparatus in an embodiment includes at least three arms and a switching part. At least the three arms include a plurality of first arms to be used for power conversion and at least one second arm held in a standby state. The switching part replaces the first arm with the second arm to allow the second arm to substitute for the replaced first arm functionally.

Description

  Embodiments described herein relate generally to a power conversion apparatus.

  Railway vehicles that run by receiving single-phase AC power from overhead lines such as the Shinkansen, step down the voltage of the supplied single-phase AC power with a transformer, and convert the reduced single-phase AC power into DC power with a converter. The DC power is converted into three-phase AC power by an inverter, and the motor is driven by the three-phase AC power.

JP 2004-7941 A

  By the way, in the converter for railway vehicles, since the AC power supplied from the overhead wire is single-phase AC power, the single-phase AC power is converted into DC power using two arms. Therefore, if one of the two arms of the converter breaks down, the converter cannot be used, so DC power cannot be supplied to the inverter, and the railway vehicle cannot travel. There is a problem.

  The power converter of the embodiment includes at least three arms and a switching unit. The at least three arms include a plurality of first arms used for power conversion and at least one second arm in a standby state. The switching unit replaces the function of the replaced first arm by replacing the second arm with the first arm.

FIG. 1 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the first embodiment. FIG. 2 is a diagram illustrating a configuration of a drive power system of a railway vehicle according to the first modification. FIG. 3 is a diagram illustrating a configuration of a drive power system of a railway vehicle according to the second modification. FIG. 4 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the second embodiment. FIG. 5 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the third embodiment. FIG. 6 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the fourth embodiment.

  Hereinafter, a power converter according to the present embodiment will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the first embodiment. As shown in FIG. 1, the railway vehicle according to the present embodiment includes a pantograph 12 to which AC power is supplied from an overhead wire 11 (an example of a power supply), a wheel 13 grounded via a track 13, a pantograph 12 and a wheel. 13, a transformer 15 connected in series with the vehicle 13, a power converter 100 for a vehicle connected to the overhead wire 11 via the transformer 15 and the pantograph 12 and grounded via the wheel 14 and the track 13, and power conversion A motor 120 (in this embodiment, a three-phase AC motor) that drives the railway vehicle by receiving power supplied from the device 100.

  The power conversion device 100 includes a converter 101 that performs power conversion (forward conversion) from AC power (single-phase AC power in this embodiment) supplied from the overhead wire 11 via the pantograph 12 and the transformer 15 to DC power; An inverter 102 that performs power conversion (inverse conversion) from DC power output from the converter 101 to AC power (three-phase AC power in this embodiment), and the output of the converter 101 is smoothed to stabilize the operation of the inverter 102. A filter capacitor 103 that achieves the above, a switch 104 that connects an arm C (described later) included in the converter 101 and the overhead wire 11, a switch 107 that connects an arm I (described later) included in the inverter 102 and the motor 120, A converter control unit 105 that controls the converter 101 and the switch 104; And 102 and inverter control unit 106 for controlling the switch 107, and a. In the present embodiment, the converter 101 and the inverter 102 are composed of, for example, a power semiconductor element (so-called power semiconductor device) or the like, and are housed in a single package. In this embodiment, since the power supplied from the overhead wire 11 is AC power, the switch 104 connects the overhead wire 11 and an arm C (described later) of the converter 101 via the pantograph 12 and the transformer 15. However, when the power supplied from the overhead line 11 is DC power, the switch 104 connects the overhead line 11 and an arm I (described later) of the inverter 102 via the pantograph 12 and the transformer 15.

  The converter 101 includes three arms C1, C2, and C3 including two arms C used for power conversion (hereinafter referred to as a first arm) and one arm C in a standby state (hereinafter referred to as a second arm). Have. Hereinafter, when it is not necessary to distinguish the arms C1, C2, and C3, they are simply referred to as the arm C. Thus, even if the temperature of the arm C functioning as the first arm rises, the arm C functioning as the second arm is replaced with the arm C functioning as the first arm, and the first arm is replaced. By substituting this function, power conversion by the converter 101 can be continued. In the present embodiment, converter 101 functions as arms C1 and C2 and arm C3 functions as the second arm in the initial state.

  In this embodiment, an example in which the converter 101 has three arms C will be described. However, the converter 101 has at least three arms C including a plurality of first arms used for power conversion and at least one second arm in a standby state. If you do. For example, the converter 101 may have four or more arms C. Thereby, even if two arms C as the first arm used for power conversion among the four arms C rise in temperature or the like, the two arms C as the second arms in the standby state are set as the first arms. By substituting the functioning of the first arm by replacing the two arms C that have functioned, the power conversion by the converter 101 can be continued.

  The three arms C are connected in parallel. Each arm C is connected in series with two switching elements (for example, IGBT: Insulated Gate Bipolar Transistor) connected to the overhead wire 11 via the pantograph 12 and the transformer 15, and the switching elements are arranged in a predetermined switching pattern. DC power is output by switching.

  The converter control unit 105 detects a temperature of each of the three arms C of the converter 101, and a switch that controls the switch 104 based on the temperature detection result of each arm C by the temperature detection unit 105a. And a control unit 105b.

  The inverter 102 includes four arms I1, I2, I3, I4 including three arms I functioning as first arms used for power conversion and one arm I (second arm) functioning as a second arm in a standby state. Have Hereinafter, when it is not necessary to distinguish the arms I1, I2, I3, and I4, they are simply referred to as the arm I. As a result, even if any of the three arms I functioning as the first arm rises in temperature, the arm I functioning as the second arm is replaced with the arm I functioning as the first arm. By substituting the function of the first arm, the power conversion by the inverter 102 can be continued.

  The four arms I are connected in parallel. Each arm I is connected in series to two switching elements (for example, IGBT) connected to the motor 120, and outputs AC power by switching the switching elements with a predetermined switching pattern.

  In this embodiment, an example in which the inverter 102 has four arms I will be described. However, the inverter 102 has at least three arms I including a plurality of first arms used for power conversion and at least one second arm in a standby state. It should be. For example, the inverter 102 may have five arms I. Thereby, even if two arms I as the first arm rise in temperature among the five arms I, the two arms I that have been functioning as the first arms are in the standby state. The power conversion by the inverter 102 can be continued by substituting and substituting the function of the first arm. Further, when the inverter 102 converts DC power into single-phase AC power, two arms I functioning as first arms used for power conversion and one arm I functioning as a second arm in a standby state are provided. What is necessary is just to have three arms I including.

  The inverter control unit 106 detects a temperature of each of the four arms I included in the inverter 102, and a switch that controls the switch 107 based on the temperature detection result of each arm I by the temperature detection unit 106a. And a control unit 106b.

  Next, an operation of replacing the arm C functioning as the second arm with the arm C functioning as the first arm in the converter 101 will be described. The switch control unit 105b of the converter control unit 105 controls the switch 104 in order to convert the single-phase AC power supplied from the overhead wire 11 into DC power, so that two of the three arms C (for example, , Arms C1, C2) are short-circuited to the overhead wire 11 via the pantograph 12 and the transformer 15, thereby making the arms C1, C2 the first arm. Further, the switch control unit 105b controls the switch 104 to disconnect the arm C (for example, the arm C3) other than the arm C functioning as the first arm among the three arms C from the overhead wire 11, and wait for the arm C3. The second arm is in a state.

  While the power conversion by the converter 101 is performed, the switch control unit 105b acquires the detection result of the temperature of each arm C by the temperature detection unit 105a. Then, the switch control unit 105a determines whether the temperature of any of the arms C1 and C2 functioning as the first arm is higher than a predetermined temperature. Here, the predetermined temperature is an upper limit temperature that allows the use of the arm C in terms of management, and can be arbitrarily set by an administrator of the power conversion apparatus 100 or the like.

  When the temperature of any of the arms C1 and C2 functioning as the first arm is higher than a predetermined temperature, the switch control unit 105b controls the switch 104 so that the temperature detected by the temperature detection unit 105a is higher than the predetermined temperature. The high first arm (for example, arm C1) is disconnected from the transformer 15, and the arm C3 functioning as the second arm is connected to the transformer 15, and the arm C3 is short-circuited to the overhead wire 11 via the pantograph 12 and the transformer 15. . As a result, the switch 104 and the switch control unit 105b replace the second arm with the first arm whose temperature detected by the temperature detection unit 105a is higher than a predetermined temperature. In the present embodiment, the switch control unit 105b and the switch 104 function as a switching unit that replaces the second arm with the first arm and substitutes the function of the first arm.

  Next, an operation of replacing the arm I functioning as the second arm with the arm I functioning as the first arm in the inverter 102 will be described. The switch control unit 106b of the inverter control unit 106 controls the switch 107 to convert the DC power smoothed by the filter capacitor 103 into three-phase AC power, so that the three arms I ( For example, the arms I1, I2, I3) are short-circuited to the motor 120, so that the arms I1, I2, I3 are set as the first arm. Further, the switch control unit 106b disconnects the arm I (for example, the arm I4) other than the arm I functioning as the first arm among the four arms I from the motor 120, and the arm I4 is in the standby state. And

  The switch control unit 106b acquires the detection result of the temperature of each arm I by the temperature detection unit 106a while the inverter 102 performs power conversion. Then, the switch control unit 106b determines whether or not the temperature of any of the arms I1, I2, and I3 that function as the first arm is higher than a predetermined temperature. Here, the predetermined temperature is an upper limit temperature that allows the use of the arm I in terms of management, and can be arbitrarily set by an administrator of the power conversion apparatus 100 or the like.

  When the temperature of any of the arms I1, I2, and I3 that function as the first arm is higher than a predetermined temperature, the switch control unit 106b controls the switch 107 so that the temperature detected by the temperature detection unit 106a is predetermined. A first arm (for example, arm I1) higher than the temperature is disconnected from the motor 120, and an arm I4 functioning as a second arm is short-circuited with the motor 120. As a result, the switch 107 and the switch control unit 105b replace the second arm with the first arm whose temperature detected by the temperature detection unit 106a is higher than a predetermined temperature. In the present embodiment, the switch control unit 106b and the switch 107 function as a switching unit that replaces the second arm with the first arm and substitutes the function of the first arm.

  As described above, according to the power conversion device 100 according to the first embodiment, when the temperature of any one of the arms C functioning as the first arm is higher than the upper limit temperature permitted for use of the arm C in terms of management. However, since the converter 101 can continuously perform power conversion, the traveling of the railway vehicle can be continued. In addition, according to the power conversion device 100 according to the first embodiment, even if the temperature of any of the arms I functioning as the first arm is higher than the upper limit temperature permitted for use of the arm I, the inverter Since the power conversion can be continuously performed by 102, the traveling of the railway vehicle can be continued.

(Modification 1)
This modification is an example in which, of the converter and the inverter, only the converter has an arm that functions as the second arm in addition to the arm that functions as the first arm. In the following description, description of the same parts as those in the first embodiment is omitted.

  FIG. 2 is a diagram illustrating a configuration of a drive power system of a railway vehicle according to the first modification. As in the first embodiment, the converter 101 of the power conversion device 200 according to the present modification includes two arms C that function as first arms used for power conversion and a second arm that functions as a second arm in a standby state. It has three arms C1, C2, C3 including the arms.

  On the other hand, the inverter 201 of the power conversion device 200 according to the present modification has only three arms I1, I2, and I3 that function as first arms used for power conversion. Therefore, in this modification, the inverter control unit 202 cannot replace the arm I that has been functioning as the first arm (the arm I that has risen in temperature or the like) with another arm that is in a standby state.

  As described above, according to the power conversion device 200 according to the first modification, even when the temperature of any of the arms C functioning as the first arm becomes higher than the upper limit temperature permitted for use or management of the arm C, the converter Since the power conversion can be continued by 101, the traveling of the railway vehicle can be continued.

  However, according to this modification, the converter 101 (an example of the second conversion unit) has the same number of arms C as the arms I of the inverter 201 (an example of the first conversion unit) (in this modification, three arms C). ). Thus, the converter 101 and the inverter 201 can have the same circuit configuration, so that it is not necessary to design and manufacture the converter 101 and the converter 101 separately from the inverter 201. Therefore, the manufacturing cost of the converter 101 and the inverter 201 is increased due to the mass production effect. Can be lowered.

(Modification 2)
This modification is an example in which, of the converter and the inverter, only the inverter has an arm that functions as the second arm in addition to the arm that functions as the first arm. In the following description, description of the same parts as those in the first embodiment is omitted.

  FIG. 3 is a diagram illustrating a configuration of a drive power system of a railway vehicle according to the second modification. Converter 301 of power conversion device 300 according to the present modification has only two arms C1 and C2 that function as first arms used for power conversion. For this reason, in this modification, converter control unit 302 cannot replace arm C (arm C that has risen in temperature, etc.) functioning as the first arm with another arm that is in a standby state.

  On the other hand, the inverter 102 of the power conversion device 300 according to the present modification functions as the three arms I functioning as the first arm used for power conversion and the second arm in the standby state, as in the first embodiment. It has four arms I1, I2, I3, I4 including one arm I.

  As described above, according to the power conversion device 300 according to the second modification, even if the temperature of any of the arms I functioning as the first arm is higher than the upper limit temperature permitted for use of the arm I, the inverter Since power conversion can be continued by 102, traveling of the railway vehicle can be continued.

(Second Embodiment)
The present embodiment is an example in which at least three arms are used as the first arm in order from the arm with the lowest detected temperature. In the following description, description of the same parts as those in the first embodiment is omitted.

  FIG. 4 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the second embodiment. In the present embodiment, the converter 401 has four or more arms C1 to CN. Hereinafter, when it is not necessary to distinguish the arms C1 to CN, they are simply referred to as the arm C. Of the arms C1 to CN, two arms C are first arms, and the remaining two or more arms C are second arms. As a result, even if the temperature of the plurality of arms C as the first arm rises, the plurality of arms C functioning as the second arm are replaced with the plurality of arms C functioning as the first arm. By substituting the function of the first arm, the power conversion by the converter 401 can be continued.

  In the present embodiment, the inverter 402 has five or more arms I1 to IN. Hereinafter, when it is not necessary to distinguish the arms I1 to IN, they are simply referred to as the arm I. Of the five or more arms I1 to IN, three arms I are defined as first arms, and the remaining two or more arms I are defined as second arms. As a result, even if the temperature of the plurality of arms I among the three arms I functioning as the first arm rises, the plurality of arms I functioning as the second arm function as the plurality of arms functioning as the first arm. By substituting I for the function of the replaced first arm, the power conversion of the inverter 402 can be continued.

  Next, an operation of replacing the arm C functioning as the second arm with the arm C functioning as the first arm in the converter 401 will be described. In the present embodiment, the switch control unit 403b of the converter control unit 403 has a temperature of at least one of the arms C (for example, the arms C1 and C2) as the first arm (for example, the arm C2) higher than a predetermined temperature. In this case, the switch 104 is controlled to disconnect the arm C2 whose temperature detected by the temperature detection unit 105a is higher than a predetermined temperature from the transformer 15. Further, the switch control unit 403b controls the switch 104, and among the arms C1, C3 to CN, the two arms C (for example, the arms C1 and CN, for example) from the arm C detected by the temperature detection unit 105a in descending order. And the selected arm C is short-circuited to the overhead wire 11 via the pantograph 12 and the transformer 15.

  That is, the switch control unit 403b excludes the arm C whose temperature detected by the temperature detection unit 105a is higher than a predetermined temperature among the arms C1 to CN included in the converter 401, and has an arm whose temperature detected by the temperature detection unit 105a is low. The first arm is in order from C. Thereby, even if the temperature of the other arms C excluding the arm C whose detected temperature is higher than the predetermined temperature does not exceed the predetermined temperature, only the specific arm C whose temperature is higher among the other arms C is the first. Since it is possible to avoid the functioning as an arm and continuing to use it in a high temperature state, it is possible to prevent the deterioration from proceeding by using only the specific arm C in a high temperature state.

  In the present embodiment, the switch control unit 403b performs switching of the arm C as the first arm when the temperature of at least one of the arms C as the first arm is higher than a predetermined temperature. Alternatively, the arm C may be selected in descending order of the temperature detected by the temperature detection unit 105a to switch the arm C as the first arm. In other words, the switch control unit 403b replaces the second arm with the first arm so that at least three arms C function as the first arm at the same time.

  Specifically, the switch control unit 403b replaces the arm C functioning as the second arm with the arm C functioning as the first arm every other day. For example, when the arm C included in the converter 401 is three arms C1, C2, and C3, the switch control unit 403b causes the arm C2 one day after the day when the arms C1 and C2 are the first arm (the next day). , C3 is the first arm, and one day later, arms C3, C1 are the first arm. In this way, by switching the arm C as the first arm every other day, only a specific arm is used as the first arm and the deterioration is prevented from proceeding quickly (in other words, the arm C is used equally). be able to). Further, the switch control unit 403b may switch the arm C serving as the first arm according to the week, the date, and the operation state of the railway vehicle (for example, whether the railway vehicle is up or down).

  Next, an operation of replacing the arm I functioning as the second arm with the arm I functioning as the first arm in the inverter 402 will be described. In the present embodiment, the switch control unit 404b of the inverter control unit 404 is configured such that the temperature of at least one of the arms I (for example, the arms I1, I2, and I3) as the first arm (for example, the arm I2) is a predetermined temperature. When the temperature is higher, the switch 107 is controlled to disconnect the arm I2 whose temperature detected by the temperature detection unit 105a is higher than a predetermined temperature from the motor 120. Further, the switch control unit 404b controls the switch 107, and among the arms I1 and I3 to IN, the three arms I (for example, the arms I1 and I3) are sequentially arranged from the arm I detected by the temperature detection unit 106a. , IN) and the selected arm I is short-circuited with the motor 120.

  That is, the switch control unit 404b has an arm whose temperature detected by the temperature detection unit 106a is low except for the arm I whose temperature detected by the temperature detection unit 106a is higher than a predetermined temperature among the arms I1 to IN of the inverter 402. The first arm in order from I. Thereby, even if the temperature of the other arms I excluding the arm I whose detected temperature is higher than the predetermined temperature does not exceed the predetermined temperature, only the specific arm I whose temperature is higher among the other arms I is the first. Since it is possible to avoid the functioning as an arm and continuing to use it in a high temperature state, it is possible to prevent the deterioration from progressing by using only the specific arm I in a high temperature state.

  In the present embodiment, the switch control unit 404b switches the arm I serving as the first arm when the temperature of at least one of the arms I serving as the first arm is higher than a predetermined temperature. In addition, the arm I may be selected in order from the lowest temperature detected by the temperature detection unit 106a to switch the arm I as the first arm. In other words, the switch control unit 404b replaces the second arm with the first arm so that the time during which each of the at least four arms I functions as the first arm is the same.

  Specifically, the switch control unit 404b replaces the arm I functioning as the second arm with the arm I functioning as the first arm every other day. For example, when the arm 401 of the converter 401 has four arms I1, I2, I3, and I4, the switch control unit 404b is one day after the day when the arms I1, I2, and I3 are set as the first arm (next day). ), Arms I2, I3, and I4 are the first arm, and after two days, arms I3, I4, and I1 are the first arm. In this way, by switching the arm I as the first arm every other day, only a specific arm is used as the first arm and the deterioration is prevented from proceeding quickly (in other words, the arm I is used equally). be able to). In addition, the switch control unit 404b may perform switching of the arm I serving as the first arm according to the week, date, and operation state of the railway vehicle (for example, whether the railway vehicle is up or down).

  Thus, according to the power converter 400 concerning 2nd Embodiment, even if the temperature of the other arms C except the arm C whose detected temperature is higher than predetermined temperature does not exceed predetermined temperature, the said Since only the specific arm C having a high temperature among the other arms C is used as the first arm and can be kept from being used in a high temperature state, deterioration can be caused by continuing to use only the specific arm C in a high temperature state. It can be prevented from moving forward. Moreover, according to the power converter 400 concerning 2nd Embodiment, even if the temperature of the other arm I except the arm I whose detected temperature is higher than predetermined temperature does not exceed predetermined temperature, the said other Since only the specific arm I having a high temperature among the arms I is used as the first arm and can be kept from being used in a high temperature state, the deterioration proceeds when only the specific arm I is continuously used in a high temperature state. Can be prevented.

(Third embodiment)
The present embodiment is an example in which the second arm can be used as a circuit element other than the first arm. In the following description, description of the same parts as those in the first embodiment is omitted.

  FIG. 5 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the third embodiment. In the present embodiment, the power conversion apparatus 500 includes a brake chopper 502 (regenerative brake) of a railway vehicle (an example of a vehicle) in addition to the configuration of the power conversion apparatus 100 according to the first embodiment.

  In this embodiment, converter 501 includes arm C3 as a second arm that can be used as a circuit element of brake chopper 502 of a railway vehicle, in addition to arms C1 and C2 as first arms used for power conversion. have. Thereby, in addition to the arm C as the first arm, it is not necessary to provide the dedicated arm C as the second arm, so that the converter 501 can be downsized and the converter 501 can be reduced in cost. In the present embodiment, the arm C3 that functions as the second arm is an arm that can also be used as a circuit element of the brake chopper 502 of the railway vehicle, but other circuit elements (for example, a charging device) other than the first arm. However, the arm is not limited to this as long as it can be used.

  In this embodiment, the railway vehicle has a brake chopper 502 that includes the arm C3 as a circuit element while either of the arms C1 and C2 functioning as the first arm is replaced by the arm C3 as the second arm. Therefore, the braking force by a mechanical brake (not shown) is increased to decelerate.

  Although not shown, in the inverter 102, among the four arms I, an arm I functioning as a second arm other than the three arms I functioning as the first arm used for power conversion is replaced with a circuit other than the first arm. It is good also as an arm which can be used also as elements (for example, a brake chopper of a vehicle, a charging device, etc.). Accordingly, it is not necessary to provide the dedicated arm I as the second arm in addition to the arm I as the first arm, so that the inverter 102 can be downsized and the inverter 102 can be reduced in cost.

  As described above, according to the power conversion device 500 according to the third embodiment, it is not necessary to provide a dedicated arm as the second arm in addition to the arm as the first arm, and thus the converter 501 (or the inverter 102). ) And the cost of the converter 501 (or the inverter 102) can be reduced.

(Fourth embodiment)
The present embodiment is an example in which when the arm failure is detected, the first arm in which the failure is detected is replaced with the second arm. In the following description, description of the same parts as those in the first embodiment is omitted.

  FIG. 6 is a diagram illustrating a configuration of a drive power supply system of a railway vehicle according to the fourth embodiment. In the present embodiment, the power conversion device 600 includes, in addition to the configuration of the power conversion device 100 according to the first embodiment, an arm C as a first arm (in the present embodiment, an arm C connected to the transformer 15). A current detection unit 601 for detecting a current flowing through the converter, and a converter control unit 602. The converter control unit 602 detects a failure in the failure detection unit 602c that detects a failure of the arm C based on the current detection result by the current detection unit 601 and the failure detection unit 602c. A switch control unit 602b that replaces the arm C functioning as the first arm. In the present embodiment, the power conversion device 600 includes a current detection unit 603, 604 that detects a current flowing in the arm I as the first arm (in the present embodiment, the arm I connected to the motor 120), an inverter And a control unit 605. The inverter control unit 605 detects the failure of the arm I based on the current detection results by the current detection units 603 and 604, and the failure detection unit 605c detects the failure of the arm I as the second arm. And a switch control unit 605b that replaces the detected arm I functioning as the first arm.

  The failure detection unit 602c detects the failure of the arm C based on the current detection result by the current detection unit 601. In the present embodiment, the failure detection unit 602c detects the current by the current detection unit 601 when the two arms C are connected to the transformer 15 for all combinations of the two arms C among the three arms C. Based on the result, it is determined whether or not there is a failure in one of the two arms C. Specifically, the failure detection unit 602c detects when the current detection result by the current detection unit 601 exceeds the upper limit of the current flowing through the two arms C or when no current flows through the two arms C. It is determined that one of the two arms C has a failure. The failure detection unit 602c determines the presence / absence of a failure in one of the two arms C for all combinations of the two arms C among the three arms C. Then, the failure detection unit 602c detects the arm C having the failure among the three arms C based on the combination of the determination results of the presence / absence of the failure performed on all the combinations of the two arms C among the three arms C. To do.

  When the failure detection unit 602c detects the failure of the arm C, the switch control unit 602b controls the switch 104 to disconnect the first arm (for example, the arm C1) in which the failure is detected from the transformer 15, and The arm C3 as the two arms is connected to the transformer 15 and replaced with the first arm. Accordingly, the switch 104 and the switch control unit 602b replace the second arm with the first arm in which the failure is detected by the failure detection unit 602c.

  Further, the failure detection unit 605c detects a failure of the arm I based on the current detection result by the current detection units 603 and 604. In the present embodiment, the failure detection unit 605c has the currents detected by the current detection units 603 and 604 when the three arms I are connected to the motor 120 for all combinations of the three arms I of the four arms I. The presence or absence of a failure of any of the three arms I is determined based on the detection result. Specifically, the failure detection unit 605c determines that the current detection result by the current detection units 603 and 604 exceeds the upper limit of the current flowing through the three arms I, or no current flows through the three arms I. In this case, it is determined that one of the three arms I has a failure. The failure detection unit 605c determines the presence / absence of failure of any of the three arms I for all combinations of the three arms I of the four arms I. Then, the failure detection unit 605c detects the arm I having the failure among the four arms I based on the combinations of the determination results of the presence / absence of the failure performed for all the combinations of the three arms I among the four arms I. To do.

  When the failure detection unit 605c detects a failure in the arm I, the switch control unit 605b controls the switch 107 to disconnect the first arm (for example, the arm I1) in which the failure is detected from the motor 120, and The arm I4 as the two arms is connected to the motor 120 and replaced with the first arm. Accordingly, the switch 107 and the switch control unit 605b replace the second arm with the first arm in which the failure is detected by the failure detection unit 605c.

  As described above, according to the power conversion device 600 according to the fourth embodiment, power conversion can be continuously performed by the converter 101 even when a failure occurs in any of the arms C functioning as the first arm. Therefore, traveling of the railway vehicle can be continued. Further, according to the power conversion device 600 according to the present embodiment, even if a failure occurs in any of the arms I functioning as the first arm, power conversion can be continuously performed by the inverter 102. Can continue running.

  As described above, according to the first to fourth embodiments, the temperature of any one of the arms functioning as the first arm is higher than the upper limit temperature that is permitted for use of the arm or a failure occurs. Even in this case, the power conversion can be continuously performed by the power conversion device, so that the traveling of the railway vehicle can be continued.

  In the above-described embodiment, in the power conversion device that performs both power conversion from AC power to DC power and power conversion from DC power to AC power, the arm that functions as the second arm functions as the first arm. However, if the power conversion device performs at least one of power conversion from AC power to DC power and power conversion from DC power to AC power, the second arm is described. It is possible to perform a process of replacing the arm functioning as the arm functioning as the first arm.

  In the above-described embodiment, the example in which the process of replacing the arm functioning as the second arm with the arm functioning as the first arm in the vehicle power conversion device has been described. However, power conversion is performed. If it is a power converter, it is possible to perform a process of replacing the arm functioning as the second arm with the arm functioning as the first arm.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11 Overhead Line 12 Pantograph 13 Line 14 Wheel 15 Transformer 100, 200, 300, 400, 500, 600 Power Converter 101, 301, 401, 501 Converter 102, 201, 402 Inverter 104, 107 Switch 105, 302, 403, 602 Converter Control unit 105a, 106a Temperature detection unit 105b, 106b, 403b, 404b, 602b, 605b Switch control unit 106, 202, 404, 605 Inverter control unit 502 Brake chopper 601, 603, 604 Current detection unit 602c, 605c Failure detection unit C , I arm

Claims (9)

At least three arms including a plurality of first arms used for power conversion and at least one second arm in a standby state;
A switching unit that replaces the second arm with the first arm to replace the function of the replaced first arm;
The power converter provided with. A temperature detection unit for detecting the temperature of the arm;
2. The power conversion device according to claim 1, wherein the switching unit replaces the second arm with the first arm whose temperature detected by the temperature detection unit is higher than a predetermined temperature.   3. The switching unit according to claim 2, wherein the switching unit is configured as the first arm in order from the arm whose temperature detected by the temperature detection unit is low, except for the arm whose temperature detected by the temperature detection unit is higher than the predetermined temperature. The power converter described. A failure detection unit for detecting a failure of the arm;
4. The power conversion device according to claim 1, wherein the switching unit replaces the second arm with the first arm in which a failure is detected by the failure detection unit. 5. A first converter having at least three arms and performing power conversion from DC power to AC power;
A second converter having the same number of arms as the first converter and performing power conversion from AC power to DC power;
The power converter according to any one of claims 1 to 4, further comprising:   The power conversion device according to claim 5, wherein the first conversion unit and the second conversion unit are housed in a single package.   7. The switch according to claim 1, wherein the switching unit replaces the second arm with the first arm so that at least three of the arms function as the first arm at the same time. 8. The power converter described.   The power converter according to any one of claims 1 to 7, wherein the second arm can be used as a circuit element other than the first arm. The power conversion device is a power conversion device for a vehicle,
The power conversion device according to claim 8, wherein the second arm can also be used as a brake chopper of the vehicle.

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