JP5921738B2 - Filter device and electric vehicle drive control device - Google Patents

Description

  The present invention relates to a filter device and an electric vehicle drive control device.

  As a conventional electric vehicle drive control device, for example, in Patent Document 1 below, in order to suppress a noise current generated when the inverter drives a motor from flowing out to the DC overhead line side, the input side of the inverter (DC overhead line side) In addition, a filter device including a filter reactor and a filter capacitor is provided.

  On the other hand, when the noise current generated by the inverter is large, or when the noise current regulation value is low (that is, when the resistance to noise current is small), for example, the following patent document In some cases, a two-stage filter is constructed as shown in FIG.

  The filter device disclosed in Patent Document 2 is constructed using a filter reactor that magnetically couples a two-stage filter for enhancing the noise current suppression effect (outflow prevention effect) than the filter device of Patent Document 1. Then, the third filter reactor is electrically connected to the intermediate tap drawn from the connection point between the first filter reactor constituting the first stage filter and the second filter reactor constituting the second stage filter. Are connected to each other. The third filter reactor is for canceling the negative equivalent inductance caused by the magnetic coupling between the first and second filter reactors. An original two-stage filter can be obtained by providing the third filter reactor. Therefore, the attenuation characteristic of the noise current in the high frequency range, which deteriorates when there is no third filter reactor, can be the original one of the two-stage filter. By using a magnetically coupled filter reactor, the filter reactor can be reduced in size.

Japanese Patent Laid-Open No. 02-151202 JP 2002-315101 A

  However, in the filter device of Patent Document 2, when the second filter capacitor connected to the intermediate tap causes a short-circuit failure, the short-circuit current from the overhead wire does not flow to the first filter reactor, and the second filter Since the current flows only through the reactor, the fault current flowing through the third filter capacitor that has caused the short-circuit fault is increased, and the circuit breaker in the higher system may be operated rather than the circuit breaker provided between the overhead wire and the filter device. There is. If the circuit breaker of the host system is operated, the power supply to other electric vehicles is also stopped, so that there is a problem that the vehicle operation of the entire railway operator is greatly hindered.

  Even if the breaker of the host system is not operated and the breaker of the host vehicle is operated, it is difficult to determine whether the second filter capacitor has failed or the inverter has failed. I can't let you. For this reason, there was a problem that it was not possible to run on its own to a vehicle base or the like, which hindered the railway operators' vehicle operations.

  In addition, when the second filter capacitor causes a short-circuit failure, the filter characteristics are greatly changed, so that there is a problem that the noise current suppressing effect is deteriorated.

  A specific frequency bypass filter having an inductance element and a capacitance element for improving the attenuation rate of noise current in a specific frequency range is connected to the power supply source without having a sufficiently large inductance element. This is the same even when a short circuit fault occurs in the specific frequency bypass filter.

  The present invention has been made in view of the above, and even when a capacitance element connected without having a sufficiently large inductance element between the power supply source causes a short-circuit fault, It is an object of the present invention to obtain a filter device that can quickly remove a failure and operate an inverter after the failure is removed.

  A filter device according to the present invention is a filter device that is provided between an overhead line and an inverter that receives power from the overhead line, and that is electrically connected to a circuit breaker of a higher system than the overhead line, and includes a DC part of the inverter Between the high potential side bus and the low potential side bus of the DC portion of the inverter, a first filter capacitor provided in parallel with the DC portion of the inverter, and closer to the overhead wire side than the first filter capacitor A second filter capacitor provided in parallel with the first filter capacitor between the high potential side bus and the low potential side bus, and the first filter capacitor and the second filter capacitor. Between the first filter reactor provided on the high potential bus, the second filter capacitor, and the overhead wire, on the high potential bus. A second filter reactor magnetically coupled to the first filter reactor, a connection point between the first filter reactor and the second filter reactor magnetically coupled, and the low potential bus And a circuit cutting part connected in series to the second filter capacitor.

  According to the present invention, even when a capacitance element connected without a sufficiently large reactor between the power supply source causes a short-circuit failure, the failure is surely removed, and the failure is eliminated. There is an effect that the inverter can be operated later.

FIG. 1 is a diagram illustrating a configuration example of an electric vehicle drive control apparatus according to Embodiment 1 of the present invention. FIG. 2 is a diagram showing an equivalent circuit of the filter circuit portion shown in FIG. FIG. 3 is a diagram showing a simulation result by the equivalent circuit of FIG. FIG. 4 is a diagram illustrating a configuration of an electric vehicle drive control device disclosed in Patent Document 1 and the like. FIG. 5 is a diagram showing the configuration of the electric vehicle drive control device disclosed in Patent Document 2. As shown in FIG. FIG. 6 is a diagram for explaining the filter characteristics of the filter device shown in FIG. FIG. 7 is a diagram for explaining a case where a short-circuit failure occurs in the capacitor and a short-circuit current flows in the electric vehicle drive control device shown in FIG. 4. FIG. 8 is a diagram for explaining a case where a short-circuit failure occurs in the overhead-side capacitor and a short-circuit current flows in the electric vehicle drive control device shown in FIG. FIG. 9 is a diagram showing a configuration example of an electric vehicle drive control apparatus according to Embodiment 2 of the present invention. FIG. 10 is a diagram illustrating an example in which a specific frequency bypass filter is inserted closer to the overhead line than the filter reactor in the one-stage filter device. FIG. 11 is a diagram illustrating an example in which a specific frequency bypass filter is inserted on the load side of the filter reactor in the one-stage filter device. FIG. 12 is a diagram illustrating an example in which a specific frequency bypass filter is inserted closer to the overhead line than the second filter reactor in a two-stage filter device using a magnetically coupled filter reactor. FIG. 13 is a diagram illustrating an example in which a specific frequency bypass filter is inserted on the load side of the first filter reactor in a two-stage filter device using a magnetically coupled filter reactor. FIG. 14 is a diagram illustrating an example in which a specific frequency bypass filter is inserted on the overhead line side of the second filter reactor in a two-stage filter device using a filter reactor that is not magnetically coupled. FIG. 15 is a diagram illustrating an example when a specific frequency bypass filter is inserted on the load side of the first filter reactor in a two-stage filter device using a filter reactor that is not magnetically coupled. FIG. 16 is a diagram illustrating a filter characteristic in which an attenuation factor in the vicinity of 25 Hz is improved in the filter configuration apparatus shown in FIG.

  Hereinafter, a filter device and an electric vehicle drive control device according to an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a configuration example of an electric vehicle drive control apparatus according to Embodiment 1 of the present invention. The electric vehicle drive control device according to the first embodiment is configured to include a filter device 5, an inverter 6, and a motor (induction motor or synchronous motor) 7 as main components. The filter device 5 is disposed between the circuit breaker 4 provided on the DC power supply source side and the inverter 6, and includes first to third filter reactors (51 a to 51 c), first and second filters. A capacitor (52a, 52b) and a fuse 53 as a circuit disconnecting unit are provided. The fuse 53 melts when a current larger than the rated current flows and cuts the circuit. The circuit disconnection unit may not be a fuse as long as it cuts the circuit when a current larger than the rated current flows.

  In FIG. 1, the DC voltage applied between the overhead line 1 and the rail 2, which is a power supply source of DC power, is brought into contact with the current collector 3 on the high potential side of the DC voltage, and the circuit breaker 4 and the filter device 5. Is applied to the high potential side bus 55a of the DC part of the inverter 6. The low potential side bus 55 b of the DC part of the inverter 6 is connected to the rail 2 via the wheel 8. The inverter 6 converts the DC power to be received into AC power that has been subjected to variable voltage variable frequency control (VVVF control) or fixed voltage variable frequency control (CVVF control), and supplies the AC power to a motor 7 for driving the vehicle. The filter device 5 removes the noise current generated by the inverter 6 and prevents the noise current from flowing to the overhead wire 1.

  The first and second filter reactors (51a, 51b) shown in FIG. 1 are constituted by a reactor with an intermediate tap, and two inductance elements, that is, a first filter reactor 51a and a second filter, depending on the intermediate tap position. The reactor 51b is divided. The inverter side of the reactor with the intermediate tap is the first filter reactor 51a, and the power supply source side of the intermediate tap is the second filter reactor 51b. In addition, you may comprise a 1st filter reactor and a 2nd filter reactor as another reactor. In the case of two separate reactors, they may be magnetically coupled to each other or may not be magnetically coupled.

  The first and second filter reactors (51 a, 51 b) are connected to the high potential side bus 55 a of the DC part of the inverter 6. Since the reactor has an intermediate tap, the first filter reactor 51a and the second filter reactor 51b are magnetically coupled.

  One end of the first filter capacitor 52a is connected to the high potential side bus 55a of the DC part of the inverter 6 to which one end of the first filter reactor 51a is connected, and the other end of the first filter capacitor 52a is connected to the DC of the inverter 6. Connected to the low potential side bus 55b. That is, the first filter capacitor 52 a is provided in parallel with the DC portion of the inverter 6. The first filter capacitor 52a forms a first-stage filter circuit (Low Pass Filter: LPF circuit) together with the first filter reactor 51a. The first filter reactor 51a is also simply referred to as a filter reactor, and the first filter capacitor 52a is also simply referred to as a filter capacitor.

  One end of the fuse 53 is connected to an intermediate tap 57 drawn from a connection point 54 between the first filter reactor 51a and the second filter reactor 51b, and the other end of the fuse 53 is connected to one end of the second filter capacitor 52b. The other end of the second filter capacitor 52b is connected to one end of the third filter reactor 51c, and the other end of the third filter reactor 51c is connected to the low potential side bus 55b. That is, the series circuit portion 56 in which the second filter reactor 51b, the fuse 53, the second filter capacitor 52b, and the third filter reactor 51c are connected in series is connected to the overhead line 1 and the low-potential side bus 55b via the intermediate tap 57. It is comprised so that it may be connected between.

  The series circuit unit 56 including the second filter reactor 51b, the fuse 53, the second filter capacitor 52b, and the third filter reactor 51c constitutes a second-stage filter circuit (LPF circuit). The second filter reactor 51b is an inductance element constituting a series circuit part, the fuse 53 is a circuit disconnection part, and the second filter capacitor 52b is a capacitance element. At the connection point 54 between the first filter reactor 51a and the second filter reactor 51b, one end of the first filter reactor 51a on the power supply source side of the DC power is connected to the series circuit unit 56.

  In FIG. 1, the fuse 53, the second filter capacitor 52b, and the third filter reactor 51c included in the series circuit unit 56 are connected in series in this order. These are connected in series so as to be connected between the intermediate tap 57 and the low potential side bus 55b. The connection order of these elements may be changed. For example, the fuse 53, the third filter reactor 51c, and the second filter capacitor 52b may be arranged in this order from the high potential side. However, when repairing after a short-circuit failure of the second filter capacitor, which will be described later, since the fuse is blown, the second filter capacitor becomes the ground potential, and the work becomes easy. Therefore, the fuse is preferably arranged on the high potential side as shown in FIG.

FIG. 2 is a diagram showing an equivalent circuit of the filter device 5 shown in FIG. In FIG. 2, L ₁ and L ₂ are self-inductances of the first and second filter reactors (51a and 51b), and M is a mutual inductance between the first and second filter reactors (51a and 51b). , L _S is the self-inductance of the third filter reactor 51c, and C ₁ and C _S are the capacitances of the first and second filter capacitors (52a, 52b). R _S is a resistance component of a circuit having the fuse 53, the second filter capacitor 52b, and the third filter reactor 51c.

Next, a simulation result by the equivalent circuit of FIG. 2 will be described. FIG. 3 is a diagram (graph) showing a simulation result by the equivalent circuit of FIG. 3, the solid line is the attenuation factor waveform when not equalize L _1, L _2, the dashed line is a phase waveform when not equalize L _1, L _2, dashed line L _1, L ₂ is an attenuation factor waveform when ₂ is made uniform, and a two-dot chain line is a phase waveform when L ₁ and L ₂ are made equal. In the following description, since the value of the resistance component R _s of the series circuit portion is very small, it will be ignored. Further, the negative inductance component (−M) generated with respect to the current flowing through the intermediate tap 57 due to the magnetic coupling of the first and second filter reactors (51a, 51b) is the inductance component (M of the third filter reactor 51c). ) And the inductance value of the circuit between the intermediate tap 57 and the low potential side bus 55b is assumed to be zero or sufficiently small. That is, the third filter reactor 51c is a coupling compensation inductance element that compensates for a negative equivalent inductance component generated with respect to a current flowing through the intermediate tap 57 due to magnetic coupling of the first and second filter reactors (51a, 51b). is there.

First, when the current flowing from the inverter 6 side to the filter device 5 is I _in and the current flowing from the filter device 5 to the overhead wire 1 side is I _out , it can be expressed as a ratio of the output current I _out and the input current I _in. The noise current suppression ratio (I _out / I _in ) can be expressed by the following equation. The suppression ratio is also called the attenuation rate.

In the above equation, L _1M and L _2M are the equivalent inductance of the first filter reactor 51a and the equivalent inductance of the second filter reactor 51b, and are represented by L _1M = L ₁ + M and L _2M = L ₂ + M. The L means the sum of the equivalent inductance L _1M of the first filter reactor 51a and the equivalent inductance L _{2M of} the second filter reactor 51b. There is a relationship of L = L _1M + L _2M = L ₁ + L ₂ + 2M between L and L _1M and L _2M or between L ₁ and L ₂ .

In order to increase the attenuation rate of the noise current, it is necessary to increase the denominator of the above equation (1), but the dominant term differs depending on the frequency region having the boundary between the two resonance frequencies. Here, the frequency at which the denominator of the above equation (1) becomes zero, that is, the resonance frequency ω _R can be expressed by the following equation.

In the above equation (2), the frequency when the minus (−) sign is selected is the resonance frequency on the low side (ω _{R_LOW} ), and the frequency when the plus (+) sign is selected is the high side. Resonance frequency ( _assuming ω _{R_HIGH} ). The existence of these resonance frequencies ω _{R_LOW} and ω _{R_HIGH} on the low-frequency side or high-frequency side _{makes it} possible to change the term that most affects the attenuation rate as shown in Table 1 below, and to maximize the attenuation rate. Also make it different.

  In Table 1, in regions (1) and (3), when the coefficient of the fourth-order term of the frequency ω in the equation (1) is larger than the coefficient of the second-order term, the attenuation rate increases. On the other hand, in the region (2), when the coefficient of the fourth-order term is smaller than the coefficient of the second-order term, the attenuation rate increases. As described above, the regions (1), (3) and the region (2) are mutually contradictory requirements, and there is no solution that maximizes the attenuation rate in all regions. However, considering Table 1 and FIG. 3, the following matters are apparent.

・ If L _1M = L _2M (same meaning as L ₁ = L ₂ ) and C ₁ = C _S , the two resonance frequencies ω _{R_LOW} and ω _{R_HIGH} are close to each other, so narrow the region (2). Can do.
-The area (3) has a wider frequency band than the area (2).
-The attenuation rate of area (2) is an area where attenuation by control is possible.

Therefore, in the region (3), it is possible to maximize the attenuation rate of the noise current practically under the condition that the attenuation rate is maximized, that is, L ₁ = L ₂ and C ₁ = C _S. Become. The simulation result of FIG. 3 also shows the effect of improving the attenuation rate in the region (3) by setting L ₁ = L ₂ .

  By the way, equalizing the inductances of the first and second filter reactors (51a, 51b) causes another problem. This problem will be described with reference to the drawings of FIGS.

  FIG. 4 is a diagram showing the configuration of the electric vehicle drive control device disclosed in Patent Document 1 and the like. The electric vehicle drive control device shown in FIG. 4 is configured to include a one-stage filter device 5X including a filter reactor 51X and a filter capacitor 52X.

  FIG. 5 is a diagram showing the configuration of the electric vehicle drive control device disclosed in Patent Document 2. In the filter device 5Y of the electric vehicle drive control device shown in FIG. 5, the components having the same reference numerals are the same as those of the filter device 5 according to the first embodiment described above. The difference from the filter device 5 according to the first embodiment is that a fuse 53 serving as a circuit cutting unit is not provided.

  FIG. 6 is a diagram for explaining the filter characteristics of the filter device 5Y shown in FIG. 5, and shows a gain (attenuation factor) indicating how much noise current generated in the inverter remains in the DC overhead current (graph) ). In the single-stage filter as shown in FIG. 4, the characteristic is as indicated by the broken line 56. However, if the filter is made into a two-stage structure using a magnetically coupled filter reactor, the negative filter generated by the magnetic coupling is used. Due to the equivalent inductance, the gain characteristic in the high frequency region is deteriorated as shown by the solid line 57. Therefore, if a third filter reactor 51c that cancels the negative equivalent inductance as shown in the present invention or FIG. 5 is connected, the gain characteristic in the high frequency range is the original performance of the two-stage filter as shown by the alternate long and short dash line 58. Improved.

  FIG. 7 is a diagram for explaining a case where a short-circuit failure occurs in the capacitor and a short-circuit current flows in the electric vehicle drive control device shown in FIG. 4. FIG. 8 is a diagram for explaining a case where a short-circuit failure occurs in the overhead-side capacitor and a short-circuit current flows in the electric vehicle drive control device shown in FIG. In the case of the filter device 5X having a one-stage configuration, as shown in FIG. 7, even when the inverter 6 or the filter capacitor 52X has a short circuit failure, the filter reactor 51X is sufficiently large. Can be suppressed. Therefore, the circuit breaker 4 can interrupt the short-circuit current before the short-circuit current becomes large enough to operate the higher-order circuit breaker.

  Also in the two-stage filter device 5Y shown in FIG. 5, if the first filter capacitor 52a has a short circuit fault, the current flowing through the first filter capacitor 52a having the short circuit fault is Since it flows through both of the two filter reactors (51a, 51b), the situation is the same as the one-stage filter device 5X shown in FIG.

  On the other hand, as shown in FIG. 8, the short-circuit current that flows when the second filter capacitor 52b has a short-circuit failure flows without passing through the first filter reactor 51a. Therefore, the second filter reactor 51b and the third filter reactor 51c are responsible for suppressing this short-circuit current.

However, if the number of turns of the first filter reactor 51a and the second filter reactor 51b is the same and the coupling coefficient of the magnetic circuit is sufficiently close to ₁ , L ₁ = L ₂ = M is established. Therefore, the sum L of the inductances of the first filter reactor 51a and the second filter reactor 51b is as follows.

L = L _1M + L _2M = L ₁ + L ₂ + 2M = 4L ₁ = 4L ₂ = 4M

  Further, when the above equation is modified, the following is obtained.

L ₁ = L ₂ = M = L / 4

That is, when the sum of the inductance L, the same as the reactor of one-stage configuration inductance, the self-inductance L ₁ of the first filter reactor 51a, the self-inductance L ₂ and the mutual inductance M of the second filter reactor 51b is 1 It becomes 1/4 of the inductance L in the case of the stage configuration. This may be considered as follows. In order to obtain the same inductance as that of the single stage configuration, the number of turns of the first filter reactor 51a and the second filter reactor 51b may be halved as compared with the case of the single stage configuration, and the inductance is proportional to the square of the turn ratio. Therefore, the self inductance and the mutual inductance become 1/4.

  Since the inductance of the third filter reactor 51c is set to a value that is approximately the same (substantially equal) to the mutual inductance M, it is approximately ¼. Therefore, the sum of the inductance of the second filter reactor 51b and the inductance of the third filter reactor 51c is about ½ of that in the case of the one-stage configuration. Therefore, the rate of increase of the current flowing through the second filter capacitor 52b that has caused the short circuit failure is about twice that when the first filter capacitor 52a has a short circuit failure. Therefore, the possibility of operating the circuit breaker on the higher system side than the circuit breaker 4 is higher than when the first filter capacitor 52a is short-circuited. If the circuit breaker on the upper system side is operated, power supply to other electric vehicles is also stopped, which causes a great hindrance to the vehicle operation of the entire railway operator.

  Therefore, when a two-stage filter as shown in FIG. 5 is employed, the conventional concept requires that the inductance of the second filter reactor 51b be sufficiently larger than the inductance of the first filter reactor 51a. Become. However, an optimal noise current suppression effect cannot be obtained by making the inductance of the second filter reactor 51b larger than the inductance of the first filter reactor 51a.

  Therefore, in order to obtain an optimum noise current suppressing effect while assuming a short-circuit failure of the second filter capacitor 52b, a third filter reactor 51c having a large current capacity is adopted, and the first and first filter capacitors 52b are used. It is conceivable that both of the two filter reactors (51a, 51b) have a large inductance. However, such an idea is not desirable because the filter reactor and the filter capacitor are enlarged.

  On the other hand, in the filter device of the first embodiment, a fuse 53 as a circuit disconnection unit connected in series to the second filter capacitor 52b is connected between the intermediate tap 57 and the low potential side bus 55b. Therefore, even if the second filter capacitor 52b, which is a capacitance element connected without having a sufficiently large inductance element, between the overhead line 1 that is a power supply source and a short-circuit failure occurs, the second filter capacitor 52b. There is an effect that the short-circuit current flowing through can be quickly cut off by the fuse 53.

  In the case of an electric vehicle, generally, the main circuit current of the inverter reaches several hundreds A by rating. On the other hand, since the current from the intermediate tap 57 is several A to several tens A (1/10 or less of the rating), the current rating of the fuse 53 can be made sufficiently small. For this reason, the current rating of the fuse 53 may be set to approximately 1/20 or more and 1/10 or less of the maximum current flowing through the circuit breaker 4, for example. In this case, as soon as the short-circuit current is generated, the fuse 53 can immediately melt and cut off the short-circuit current, so that the influence on the circuit operation on the inverter 6 and the motor 7 can be reduced. Reliability as an electric vehicle system can be improved.

  In addition, when the fuse 53 is blown, it is possible to quickly determine that the second filter capacitor 52b is not a short circuit failure but a failure of the inverter 6 or the motor 7, so that the apparatus can be recovered quickly. There is. Note that it is easy to determine whether or not the fuse 53 is blown, and can be realized by monitoring the voltage across the fuse 53, for example.

  Further, in the filter device of the first embodiment, the inductance of the first and second filter reactors (51a, 51b) is not set to a large value even when the filter device has a two-stage configuration, and these Since the values can be set evenly, the filter device can be downsized while ensuring the required filter characteristics.

  Further, in the filter device of the first embodiment, the first filter reactor and the second filter reactor are magnetically coupled, so that the number of turns necessary for obtaining the same inductance value is not magnetically coupled. The first and second filter reactors can be reduced in size. The size of the third filter reactor required by the magnetic coupling is considerably smaller than the first filter reactor and the second filter reactor. Therefore, the effect of downsizing the first and second filter reactors is greater, and the filter device can be downsized as a whole. The reason why the size of the third filter reactor is small is that the current flowing is 1/10 or less, so that the wire diameter of the winding can be reduced.

  Even if the fuse 53 is blown, the noise attenuation characteristic is equivalent to that of a single-stage filter. For this reason, if measures such as selecting a time zone in which the influence of noise is small are taken, self-running can be performed, and the influence on the railway operator's vehicle operation can be reduced.

  Further, when it is detected that the fuse 53 has been blown, the circuit breaker 4 on the path for supplying electric power to the electric vehicle drive control device (or the vehicle equipped with the electric vehicle drive control device) including the blown fuse. If it is opened, it is possible to operate other electric vehicle drive control devices that are not malfunctioning to drive the vehicle, and it is possible to localize the influence on the railway operator's vehicle operation.

  A specific frequency bypass filter having not only a two-stage filter device but also an inductance element and a capacitance element for improving the attenuation rate of noise current in a specific frequency region is sufficiently large between the power supply source and the filter. The present invention can also be applied to a case where connection is made without the inductance element, and has the same effect. The above is the same in other embodiments.

Embodiment 2. FIG.
In the first embodiment, the electric vehicle drive control device using the two-stage filter device in which the first filter reactor and the second filter reactor are magnetically coupled is shown. In the second embodiment, a two-stage filter device having a first filter reactor and a second filter reactor that are not magnetically coupled is used.

  FIG. 9 is a diagram showing a configuration example of an electric vehicle drive control apparatus according to Embodiment 2 of the present invention. Only differences from FIG. 1 in the first embodiment will be described. The filter device 5F includes a first filter reactor 51f and a second filter reactor 51g that are not magnetically coupled. The inductance values of the first filter reactor 51f and the second filter reactor 51g are the same. A fuse 53 and a second filter capacitor 52b are connected in series between a connection point 54F where the first filter reactor 51f and the second filter reactor 51g are connected to the low potential side bus 55b. Since the first filter reactor 51f and the second filter reactor 51g are not magnetically coupled, the filter device 5F does not have a coupling compensation inductance element that compensates for a negative equivalent inductance component due to magnetic coupling.

  The series circuit unit 56F includes a second filter reactor 51g (inductance element), a fuse 53 (circuit disconnection unit), and a second filter capacitor 52b (capacitance element) connected in series. At the connection point 54F between the first filter reactor 51f and the second filter reactor 51g, one end of the first filter reactor 51f on the power supply source side of the DC power is connected to the series circuit unit 56F.

  This second embodiment also operates in the same manner as the first embodiment. When the second filter capacitor 52b is short-circuited because the fuse 53 as a circuit disconnection unit connected in series to the second filter capacitor 52b is connected between the intermediate tap 57 and the low potential side bus 55b. However, there is an effect that the short-circuit current flowing through the second filter capacitor 52 b can be quickly cut off by the fuse 53. For this reason, the first filter reactor 51f and the second filter reactor 51g can have the same inductance value, and the attenuation characteristics in the high frequency range can be increased.

Embodiment 3 FIG.
In order to improve the attenuation rate of the noise current in the specific frequency region in the filter device, for example, a specific frequency bypass filter 50 as shown in FIGS. 10 to 15 may be connected. In this case, by appropriately selecting a capacitor and a reactor constituting the specific frequency bypass filter 50 that bypasses and removes the noise current of the specific frequency, the frequency to be attenuated is adjusted to the specific frequency and a desired attenuation is obtained. It becomes possible. Here, the filter device 5H shown in FIG. 10 is an example of the case where the specific frequency bypass filter 50 is inserted on the overhead line side of the filter reactor 51X in the one-stage filter device. The filter device 5J shown in FIG. 11 is an example of the case where the specific frequency bypass filter 50 is inserted on the load side of the filter reactor 51X. Further, the filter device 5K shown in FIG. 12 is a two-stage filter device using a magnetically coupled filter reactor, and a specific frequency bypass filter 50 is inserted on the overhead line (system) side of the second filter reactor 51b. It is an example of a case. The filter device 5N shown in FIG. 12 is an example of the case where the specific frequency bypass filter 50 is inserted on the load side of the first filter reactor 51a. Furthermore, the filter device 5P shown in FIG. 14 is a two-stage filter device using a filter reactor that is not magnetically coupled, and the specific frequency bypass filter 50 is provided closer to the overhead line (system) than the second filter reactor 51g. It is an example at the time of inserting. The filter device 5Q shown in FIG. 15 is an example of a case where the specific frequency bypass filter 50 is inserted on the load side of the first filter reactor 51f.

  The specific frequency bypass filter 50 includes a fuse 53Z that is a bypass circuit disconnection part, a bypass capacitor 52Z that is a bypass capacitance element, a bypass reactor 51Z that is a bypass inductance element, and a noise current of a specific frequency is prevented from flowing too much. The current limiting resistor 58 is connected in series. The inductance value of the bypass reactor 51Z and the capacitance value of the bypass capacitor 52Z are determined from the specific frequency and the magnitude of the flowing noise current.

  In the filter device 5H shown in FIG. 10, the specific frequency bypass filter 50 is also the series circuit unit 56H. The fuse 53Z is a circuit cutting part, the bypass reactor 51Z is also an inductance element of the series circuit part, and the bypass capacitor 52Z is also a capacitance element. A connection point 54H at which one end of the first filter reactor 51X on the power supply source side is connected to one end of the series circuit unit 56H is a point at which one end of the fuse 53Z and the first filter reactor 51X are connected.

  When the fuse 53Z is blown, the bypass capacitor 52Z and the bypass reactor 51Z are on the low potential side and work is easy. Therefore, the fuse 53Z is desirably provided on the high potential side.

For example, if L ₁ and L ₂ are equalized by a two-stage filter as shown in FIG. 3, the noise current on the high frequency side can be attenuated, but the low frequency side (in the example of FIG. 3, 15 Hz to 60 Hz). On the other hand, it increases on the contrary. For example, when there is a traffic light that causes a malfunction due to noise around 25 Hz, a filter device having a large attenuation rate around 25 Hz is desired. In such a case, for example, when a specific frequency bypass filter 50 is connected as shown in FIG. 12, the filter characteristic can secure a required attenuation rate in the vicinity of 25 Hz as shown by a one-dot chain line in FIG.

  The specific frequency bypass filter 50 may also be connected to the system side from the filter reactor 51X or the first and second filter reactors (51a, 51b) depending on the application (FIGS. 10, 12, and 14). Example). In such a case, it is necessary to connect a fuse in series with the capacitor in order to solve the above-described problem of short-circuit current at the time of capacitor failure. By connecting the fuse 53Z in series with the bypass capacitor 52Z, even if the bypass capacitor 52Z is short-circuited, the short-circuit current flowing through the bypass capacitor 52Z can be quickly cut off by the fuse 53Z.

  Further, even when connecting to the load side of the filter reactor 51X or the first and second filter reactors (51a, 51b) (examples of FIGS. 11, 13, and 15), a configuration in which a fuse is connected is preferable. If the fuse is provided in the specific frequency bypass filter 50, the failure of the filter element of the specific frequency bypass filter 50 and the failure of the inverter 6 can be separated, and the reliability as an electric vehicle system can be improved. Also, there is an effect that the influence on the vehicle operation can be reduced.

Embodiment 4 FIG.
In the fourth embodiment, the relationship between the material of the switching element used in the inverter 6 and the filter characteristics will be described. As a switching element used for the inverter 6, an element (Si element) made of silicon (Si) is generally used. Recently, however, a switching element made of silicon carbide (SiC) is used instead of the Si element. Devices (SiC devices) are attracting attention.

  The SiC element has excellent characteristics such as a large heat transfer coefficient, operation at a high temperature, and small switching loss even when the switching frequency is increased, as compared with the Si element. On the other hand, it is said that the use of SiC elements increases high frequency noise.

  On the other hand, the above-described two-stage filter has a characteristic that the noise attenuation rate on the high frequency side is smaller than that of the one-stage filter, but the noise attenuation ratio on the low frequency side is large. Therefore, the increase in the switching frequency by using the SiC element further increases the importance of the filter device of the present embodiment that employs a two-stage filter.

  Further, for a filter device for an electric vehicle drive control apparatus as in the present embodiment, an increase in high-frequency noise is a very important problem because it has a large effect on signal equipment and security equipment. However, the two-stage filter as in the present embodiment is excellent in attenuation characteristics on the high frequency side, and therefore matches the recent technical trend of employing SiC elements.

  As described above, if the SiC element is used as the switching element of the inverter 6 for the filter device of the present embodiment employing the two-stage filter, it is suitable for utilizing the characteristics of the SiC element. You can benefit from it.

  Note that SiC is an example of a semiconductor referred to as a wide band gap semiconductor, taking into account the characteristic that the band gap is larger than that of Si. In addition to SiC, a semiconductor formed using, for example, a gallium nitride-based material or diamond belongs to the wide band gap semiconductor, and other wide band gap semiconductors other than SiC may be used.

  Note that the configurations shown in the above first to third embodiments are examples of the configuration of the present invention, and can be combined with other known techniques, and can be combined within a range not departing from the gist of the present invention. Needless to say, the configuration may be modified by omitting the unit.

  Furthermore, in the above embodiment, the description of the invention is carried out for a filter device that is assumed to be applied to an electric vehicle drive control device, but the application field is not limited to this, and the power supply source Filter device which is interposed between a circuit breaker arranged on a high-voltage side DC bus when receiving DC power from the inverter and the inverter, and operates to suppress outflow of noise current from the inverter toward the power supply source side It is possible to apply widely to the structure which has this.

  As described above, the present invention is useful as a filter device for an electric vehicle drive control device.

  1 overhead wire, 2 rail, 3 current collector, 4 circuit breaker, 5, 5X, 5Y, 5F, 5H, 5J, 5K, 5N, 5P, 5Q filter device, 6 inverter, 7 motor, 50 filter for specific frequency bypass, 51a First filter reactor, 51b Second filter reactor, 51c Third filter reactor, 51X Filter reactor, 51Z Bypass reactor, 52a First filter capacitor, 52b Second filter capacitor, 52X Filter capacitor, 52Z Bypass Capacitor, 53, 53Z Fuse, 54, 54F, 54H Connection point, 55a High potential side bus, 55b Low potential side bus, 56, 56F, 56H Series circuit section, 57 Intermediate tap, 58 Current limiting resistance.

Claims (14)

A filter device provided between an overhead line and an inverter that receives power from the overhead line, and electrically connected to a breaker of a higher system than the overhead line,
A first filter capacitor provided in parallel with the DC portion of the inverter between the high potential side bus of the DC portion of the inverter and the low potential side bus of the DC portion of the inverter;
A second filter capacitor provided in parallel with the first filter capacitor between the high-potential side bus and the low-potential side bus on the overhead line side of the first filter capacitor;
A first filter reactor provided on the high potential side bus between the first filter capacitor and the second filter capacitor;
A second filter reactor provided on the high potential side bus between the second filter capacitor and the overhead wire and magnetically coupled to the first filter reactor;
A circuit disconnection unit connected in series with the second filter capacitor between the connection point of the first filter reactor and the second filter reactor magnetically coupled, and the low potential bus.
A filter device comprising: The first filter reactor constitutes a first-stage filter circuit that reduces noise current of the inverter together with the first filter capacitor,
The second filter reactor constitutes a second stage filter circuit that reduces noise current of the inverter together with the second filter capacitor.
The filter device according to claim 1. A filter device connected to a circuit breaker provided between the overhead wire and the second filter reactor,
Current rating of the circuit cutting portion, the overhead wire and filter apparatus according to claim 1 or claim 2, wherein less than the current rating of the circuit breaker provided between the second filter reactor. 4. The filter device according to claim 1 , wherein the circuit cutting unit is provided on a high potential side of the second filter capacitor. 5. Filter apparatus according to any one of claims 1 to 4, characterized in that the inductance of the first filter reactor and said second filter reactor is substantially the same value. A coupling compensation inductance element connected in parallel with the first filter capacitor and in series with the second filter capacitor and the circuit disconnection unit is provided between the high potential side bus and the low potential side bus. The filter device according to any one of claims 1 to 5 , wherein The filter device according to claim 6 , wherein an inductance of the coupling compensation inductance element is substantially equal to a mutual inductance between the first filter reactor and the second filter reactor. The inverter side is the first filter reactor with respect to the intermediate tap of the intermediate tap with the intermediate tap.
The filter device according to any one of claims 1 to 7 , wherein the overhead filter side of the reactor with the intermediate tap is closer to the overhead line than the second filter reactor. The current rating of the circuit cutting portion is 1/20 or more of the maximum current flowing through the circuit breaker, and, according to any one of claims 8 to be 1/10 or less from claim 1, wherein Filter device. An electric vehicle drive control device comprising: the inverter; the filter device according to any one of claims 1 to 9 ; and a motor driven by the inverter. 11. The electric vehicle drive control device according to claim 10 , wherein even when it is detected that the circuit disconnecting unit is operated, the electric vehicle is propelled and controlled by driving the motor by the inverter. The electric vehicle drive control device according to claim 10 , wherein the circuit breaker is opened when it is detected that the circuit cutting unit is operated. The electric vehicle drive control device according to any one of claims 10 to 12 , wherein the switching element of the inverter is formed of a wide band gap semiconductor. The electric vehicle drive control device according to claim 13 , wherein the wide band gap semiconductor is a semiconductor using silicon carbide, a gallium nitride-based material, or diamond.

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