JP4936466B2 - Power semiconductor unit - Google Patents

Description

  The present invention relates to a power semiconductor unit used as an inverter or converter that handles a large current, and more particularly to a power semiconductor unit that can be miniaturized while improving noise resistance.

  Hybrid electric vehicles and electric vehicles use power converters for driving large-capacity travel motors. The power converter is equipped with power semiconductor elements such as IGBTs (Insulated Gate Bipolar Transistors), which converts DC power into three-phase AC power to drive a driving motor, or converts three-phase AC power into DC power. The converter operates to regenerate energy.

As an example of a power converter, FIG. 1 shows an inverter unit that receives a DC power supply from a battery and drives a motor.
The inverter unit 1 includes a smoothing capacitor 4 and a power semiconductor unit 5, and the power semiconductor unit 5 includes a power semiconductor module 10 and a control board module 20.

The main battery 2 is a DC power source in which a plurality of secondary batteries are connected in series, and is connected to the P terminal 8 _P1 and the N terminal 8 _N1 of the smoothing capacitor 4 via a high voltage cable. The smoothing capacitor 4 absorbs the ripple current and stabilizes the input voltage.
The power semiconductor module 10 includes power semiconductor elements 14 _{U to} 14 _W such as IGBTs and flywheel diodes (FWD) 15 _U to 15 _W. The power semiconductor elements 14 _{U to} 14 _W and the FWD 15 _U to 15 _W are connected in reverse parallel to form a three-phase inverter circuit. U, V, W output terminal ₁₈ U ~ 18 _W of each phase is connected to the traveling motor 6 via the output bus bar ₂₉ U ~ 29 _W and high-voltage cables.

The control board 21 receives a torque command value for driving the traveling motor 6 from an upper electronic control unit (ECU). Then, the control board 21, the voltage value of the main battery 2, and while taking the positional information output from the motor position detection resolver 7, U-phase detected by U-phase current sensor 22 _U and W-phase current sensor 22 _W The current value based on the torque command value is sequentially calculated from the instantaneous value of the W-phase output current and converted into a PWM signal.
The generated PWM signal is output from the control board 21 to the driver board 11. Then, the driver substrate 11 drives the power semiconductor elements 14 _{U to} 14 _W of each phase of the power semiconductor module 10 based on the signal. Note that both the control board 21 and the driver board 11 operate upon receiving a voltage (+14 [V]) supplied from the auxiliary battery 3.

  The inverter unit 1 is used by storing the power semiconductor module 10 including the inverter circuit, the smoothing capacitor 4 and the control board module 20 in an inverter case having a cooling function.

As another example of the power converter, there is a three-phase AC-DC-AC converter shown in FIG. This three-phase AC-DC-AC converter is provided with two power semiconductor modules 10 _C and 10 _I , among which 10 _C is a three-phase PWM rectifier that operates as a converter, and 10 _I operates as an inverter. It is a three-phase inverter.

In a three-phase AC-DC-AC converter shown in FIG. 2, three-phase AC power instantaneous power is accumulated and filtered by a reactor 52 which is arranged in a three-phase input side, to the DC power by the power semiconductor module 10 _C Converted. The obtained DC power is stabilized by the smoothing capacitor 4, converted to a predetermined amplitude and frequency by the power semiconductor module 10 _I , and supplied to the three-phase load connected via the reactor 53.

The power semiconductor module 10 _C used as a three-phase PWM rectifier and the power semiconductor module 10 _I used as a three-phase inverter can both be the same as the power semiconductor module 10 shown in FIG. The circuit configuration of the control board 21 used in combination is changed according to the use such as for three-phase inverter and three-phase PWM rectifier.
Therefore, from the viewpoint of shortening the development / evaluation period and reliability evaluation cost, the driver board 11 and the control board 21 of the power semiconductor module 10 are usually independent components.

FIG. 3 is a block diagram showing a conventional structure of the inverter unit 1 shown in FIG.
The inverter unit 1 mainly includes a power semiconductor module 10, a smoothing capacitor 4 disposed above the power semiconductor module 10, and a control board 21 disposed further thereon. That is, in the conventional inverter unit 1, the smoothing capacitor 4 is disposed between the power semiconductor module 10 and the control board 21. Thereby, noise radiated from the power semiconductor elements 14 _{U to} 14 _W in the power semiconductor module 10 is shielded by the smoothing capacitor 4 so as to prevent noise from being superimposed on various signals transmitted on the control board 21 as much as possible. (For example, refer patent document 1).
As shown in FIG. 3, a U-phase current sensor 22 _U and a W-phase current sensor 22 _W are normally connected to the output side of the power semiconductor module 10, and signals (U-phase and W-phase) sensed by these are connected. A signal corresponding to the instantaneous value of the phase output current) is sent to the control board 21.
JP 2003-199363 A

[Problem 1] Increasing the size of the power semiconductor unit As shown in FIG. 3, the conventional inverter unit 1 has a configuration in which the smoothing capacitor 4 is sandwiched between the power semiconductor module 10 and the control board 21. The wiring between the semiconductor module 10 and the control board 21 and the wiring between the current sensors 22 _U and 22 _W and the control board 21 are inevitably long. Therefore, wiring is enlarged, power semiconductor unit (power semiconductor module 10, the control board 21 and the current sensor 22 _U, 22 _W) there is a problem that large in size.

Further, when the wiring becomes long, there is a problem that one wiring can be a noise source for the other wiring and noise due to the power semiconductor elements 14 _{U to} 14 _W is easily superimposed. That is, in the conventional inverter unit 1 shown in FIG. 3, even if it is possible to prevent noise from being directly superimposed on the control board 21 from the power semiconductor module 10, noise cannot be prevented from being superimposed on the wiring.

  In order to solve this problem, in the conventional inverter unit 1, each wiring is covered with an insulating material, the outside is covered with a grounded conductive material, and the outside is further covered with an insulating material. Therefore, it is necessary to separately perform a wiring shielding process. However, this shielding process causes an increase in wiring, and there is a problem that the inverter unit 1 including the power semiconductor unit is increased in size as a whole.

[Problem 2] Malfunction due to radiation noise FIG. 4 shows a power semiconductor unit 5 in which a control board 21 is arranged in the vicinity of the power semiconductor module 10 and a smoothing capacitor in order to solve the problem of the size increase of the power semiconductor unit. 4 is an inverter unit 1.
However, in the configuration in which the control board 21 is simply arranged in the vicinity of the power semiconductor module 10, noise superimposition on the control board 21 is also a problem. For example, when radiation noise due to the switching operation of the power semiconductor unit 5 is superimposed on the signal line on the control board 21, an erroneous determination is made that the power semiconductor unit 5 is abnormal although the operation of the power semiconductor unit 5 is normal. There is a possibility that the operation of the power semiconductor unit 5 is urgently stopped.

  Accordingly, an object of the present invention is to greatly reduce the influence of noise from the power semiconductor module to the control board while reducing the size of the power semiconductor unit.

In order to solve the above-described problem, a first power semiconductor unit according to the present invention includes:
A power semiconductor unit that converts direct current power into alternating current power using a power semiconductor element and outputs it to a load to be driven, an input terminal to which the direct current power is fed, an output terminal connected to the load, A power semiconductor substrate on which the power semiconductor element is provided, and a driver that is arranged in parallel with a predetermined interval on the surface side of the power semiconductor substrate and drives the power semiconductor element based on an input control signal A power semiconductor module having a circuit provided with a circuit; a current sensor for detecting a current value of a current output from the power semiconductor module to the load; and the driver board directly above the power semiconductor module. And a facing surface that faces the power semiconductor module and a non-facing surface that is the back surface of the facing surface. Shielded, on the basis of the detected current value by the current sensor, which covers the control board signal generating circuit is provided for generating the control signal, the non-opposing face side and the side surface side space of the control board And the signal generation circuit is provided on the non-facing surface of the control board, the current sensor is provided on the facing surface of the control board, and the control board includes at least one GND layer. And the noise generated from the power semiconductor module toward the signal generation circuit is shielded by sandwiching the signal generation circuit between the shield plate and the GND layer. .

In the first power semiconductor unit, preferably, the output terminal and the load are connected by an output bus bar, the current sensor has a hollow port extending in a normal direction of the power semiconductor substrate, and the output bus bar And extending in the normal direction through the hollow port.
Preferably, the DC power is supplied to the input terminal via an input bus bar, and the input bus bar is disposed to face the output bus bar and extends in the normal direction. It is characterized by.

In order to solve the above problems, the second power semiconductor unit according to the present invention is:
A power semiconductor unit that uses a power semiconductor element to convert AC power input from an AC power source into DC power and outputs the power, an input terminal to which the AC power is fed, and an output that outputs the DC power A terminal, a power semiconductor substrate provided with the power semiconductor element on a surface thereof, and a power semiconductor substrate disposed in parallel at a predetermined interval on the surface side of the power semiconductor substrate, the power semiconductor element being arranged based on an input control signal A power board having a driver circuit for driving, a current sensor for detecting a current value of a current input to the power semiconductor module from the AC power source, and a position directly above the power semiconductor module. Arranged substantially parallel to the driver board, and facing the power semiconductor module, and a back surface of the facing surface That has a non-facing surface, based on the current value detected by said current sensor, a control board signal generating circuit is provided for generating the control signal, and the non-facing surface side of the control board A shield plate that covers a space on a side surface side, the signal generation circuit is provided on the non-facing surface of the control board, and the current sensor is provided on the facing surface of the control board, Is a multilayer wiring board having at least one GND layer, and noise generated from the power semiconductor module toward the signal generation circuit is shielded by sandwiching the signal generation circuit between the shield plate and the GND layer. It is characterized by being.

In the second power semiconductor unit, preferably, the AC power is supplied to the input terminal via an input bus bar, and the current sensor has a hollow port extending in a normal direction of the power semiconductor substrate, An input bus bar extends in the normal direction through the hollow port.
Preferably, the DC power is output from the output terminal via an output bus bar, and the output bus bar is disposed to face the input bus bar and extends in the normal direction. It is characterized by.

Also, the first and second power semiconductor units, it is preferable that the shield plate is bent the ends, at least part of the space formed between the driver board and the control board, The shield plate is covered with a bent end portion.
Preferably, a transformer for supplying power to the signal generation circuit and the driver circuit is provided on the facing surface of the control board and the surface of the driver board facing the control board, respectively. The transformers are arranged so as to be shifted from each other in the plane direction of the power semiconductor substrate so that the transformers do not interfere with each other.
Further, preferably, on the facing surface of the control board, one connector for connecting to an external power supply is provided, and the driver circuit and the signal generation circuit are supplied by a voltage supplied from the outside through the connector. Is driven.

As shown in FIG. 1, in this specification, the entire apparatus that receives a supply of DC power and drives a load such as a motor based on a command from the ECU is referred to as an “inverter unit”. The part other than the smoothing capacitor is referred to as a “power semiconductor unit”.
Further, in this specification, a portion of the “power semiconductor unit” that includes a control board provided with a signal generation circuit that generates a control signal such as a PWM signal based on a command from the ECU and its peripheral components is expressed as “ A portion consisting of a driver board provided with a driver circuit for driving a power semiconductor element based on a generated control signal, a power semiconductor board provided with the power semiconductor element, and its peripheral components is called a `` control board module ''. It is called a “power semiconductor module”.

  According to the present invention, it is possible to greatly reduce the influence of noise from the power semiconductor module to the control board while reducing the size of the power semiconductor unit.

That is, for the above [Problem 1],
(1) By arranging the control board directly above the power semiconductor module, the wiring between them can be shortened to such an extent that it is hardly affected by radiation noise, while preventing the wiring from becoming enlarged, The shield process can be omitted.
(2) Furthermore, by providing the current sensor on the opposite surface of the control board, wiring between the control board and the current sensor can be omitted.

For [Problem 2] above,
(3) By arranging the signal generation circuit provided on the control board on the non-opposing surface opposite to the opposing surface facing the driver substrate (the back surface side of the opposing surface), a power semiconductor module serving as a noise source The distance can be increased, and noise generated from the power semiconductor module can be prevented from being blocked by the control board and superimposed on the signal generation circuit.
(4) Moreover, the noise emitted toward the signal generation circuit (and its peripheral circuit) can be shielded by the shield plate that covers the space on the non-facing surface side of the control board. Thereby, malfunction of a power semiconductor unit can be prevented.
(5) Furthermore, by making the control board a multilayer wiring board having at least one GND layer, the signal generation circuit (and its peripheral circuit) provided on the control board can be sandwiched between the shield plate and the GND layer. It is possible to effectively shield noise emitted toward the signal generation circuit.

  Hereinafter, preferred embodiments of a power semiconductor unit according to the present invention will be described with reference to the accompanying drawings. In the following, a power semiconductor unit that operates as a three-phase inverter will be described as an example. More specifically, a power semiconductor unit that converts DC power into three-phase AC power and outputs it to a traveling motor as a load will be described.

FIG. 5 shows an inverter unit 1 including a power semiconductor unit 5 and a smoothing capacitor 4 according to the present invention. Here, the configuration of the inverter unit 1 will be described using FIG. 5 with reference to FIG.
The smoothing capacitor 4 includes a P terminal 8 _P1 and an N terminal 8 _N1 connected to the main battery 2 (see FIG. 1), and three P terminals 8 _P2 and an N terminal 8 _N2 connected to the power semiconductor unit 5 (this application). Equivalent to the “input terminal” of the invention. The P terminal 8 _P1 and the three P terminals 8 _P2 are connected to each other inside the smoothing capacitor 4. Similarly, the N terminal 8 _N1 and the three P terminals 8 _N2 are also connected to each other inside the smoothing capacitor 4.
The power semiconductor unit 5 includes a power semiconductor module 10 and a control board module 20 provided immediately above the power semiconductor module 10. Control board module 20, control board 21 is formed by integrating the current sensor ₂₂ U, 22 _W, the input bus bars _{19 UP ~19 WP, 19 UN ~19} WN, and the output bus bar ₂₉ U ~ 29 _W and the like (FIG. 1).

  6A is an external perspective view of the power semiconductor unit 5 according to the present invention, and FIG. 6B is an exploded perspective view thereof. As shown in FIG. 6B, the power semiconductor module 10 and the control board module 20 are fixed by screwing.

FIG. 7A is an external perspective view of the power semiconductor module 10, and FIG. 7B is an exploded perspective view thereof.
The power semiconductor module 10 mainly includes a power semiconductor substrate 12, a shield plate 13 disposed on the surface side thereof, and a driver substrate 11 disposed on the further surface side thereof. The power semiconductor substrate 12 includes a three-phase inverter circuit configured by bridge-connecting a plurality of anti-parallel connectors composed of IGBTs 14 _{U to} 14 _W (corresponding to “power semiconductor element” of the present invention) and FWDs 15 _U to 15 _W. It is provided on the surface and mounted on the surface side of the radiator 32 (see FIG. 11B). A plurality of radiating fins 33 are provided on the back side of the radiator 32 and are directly cooled by a cooling medium.
The driver substrate 11 is disposed on the front surface side of the power semiconductor substrate 12 in parallel with the power semiconductor substrate 12 at a predetermined interval. The driver board 11 is provided with a driver circuit, and drives the U, V, and W phase IGBTs 14 _{U to} 14 _W provided in the power semiconductor substrate 12 based on an input control signal. Shield plate 13 is arranged between the driver board 11 and the power semiconductor substrate 12, IGBT 14 _U to 14 _W to shield electromagnetic-electrostatic noise generated by the switching of.

The driver board 11 has three phases based on a voltage (hereinafter referred to as “auxiliary battery voltage”, for example, +14 [V]) supplied from the auxiliary battery 3 via the connectors 17 _a and 17 _b and a control board 21 described later. A transformer 16 for generating an insulation voltage supplied to the inverter circuit is provided. The transformer 16 is mounted on the surface of the driver board 11 facing the control board 21.
Furthermore, the driver board 11 includes a protection circuit that detects abnormal states such as overcurrent, overheat, and overvoltage, and stops driving the IGBTs 14 _{U to} 14 _W as necessary. A signal indicating an abnormal state (hereinafter referred to as “fail signal”) is transmitted to the control board 21 via the connectors 17 _a and 17 _b . In addition, a control signal (for example, a PWM signal) generated by the control board 21 is transmitted to the driver board 11 via the connectors 17 _a and 17 _b .
In the present invention, the auxiliary battery voltage is the connector 17 _a, 17 because through _b supplied from the control board 21 side together with other signals, a connector for connecting the driver board 11 and the auxiliary battery 3 directly Is unnecessary.

8A is an external perspective view of the control board module 20 shown in FIG. 6B viewed from the back side, and FIG. 8B is an exploded perspective view thereof.
The control board module 20 mainly includes a control board 21 in which current sensors 22 _U and 22 _W are surface-mounted on a facing surface (back surface) facing the driver board 11, and a non-facing surface side (front surface) opposite to the facing surface. Side plate) and a unit cover 24. The control board 21 is disposed immediately above the power semiconductor module 10 so as to face the driver board 11, and is fixed to the unit cover 24 together with the shield plate 23 by screwing.
Thus, in the power semiconductor unit according to the present invention, by arranging the control board 21 immediately above the power semiconductor module 10, the wiring between them can be shortened to the extent that it is hardly affected by the radiation noise. In addition, the shield process for the wiring can be omitted while preventing the wiring from being enlarged.
Note that the driver board 11 and the control board 21 are spaced apart from each other by a certain distance within a range that does not hinder downsizing of the power semiconductor unit 5 in order to protect the control board 21 from noise emitted from the power semiconductor module 10. The

Input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN connected to the smoothing capacitor 4 and the input terminals of the power semiconductor module 10 are provided on the input terminal side of the unit cover 24 for each phase. The input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN project from the side of the power semiconductor module 10 and extend in the normal direction of the surface of the power semiconductor substrate 12. Further, on the output terminal side opposite to the input terminal side, an output bus bar for connecting the output terminals 18 _U to 18 _W of each phase of the power semiconductor module 10 and the traveling motor 6 driven by the power semiconductor module 10. 29 _{U to} 29 _W are provided. The input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN and the output bus bars 29 _{U to} 29 _W are arranged to face each other.

As shown in FIG. 8B, on-board type current sensors 22 _U and 22 _W are surface-mounted on the output terminal side end portion on the opposite surface side (back surface side) of the control board 21. Thereby, the wiring between the control board 21 and the current sensors 22 _U and 22 _W can be omitted. Hollow ports extending in the normal direction of the surface of the power semiconductor substrate 12 are formed in the current sensors 22 _U and 22 _W , respectively. The U-phase output bus bar 29 _U is inserted into the hollow port of the U-phase current sensor 22 _U , and the W-phase output bus bar 29 _W is inserted into the hollow port of the W-phase current sensor 22 _W. , U-phase output current I _U and W-phase output current I _W are detected.
The current sensor is arranged only in the U phase and the W phase, and is not arranged in the V phase. This is because the V-phase output current I _V can be calculated using the formula I _V = −I _U −I _W.

In addition, on the opposite surface side (back surface side) of the control board 21, the ECU 27, the connector 27 for connecting to the motor position detection resolver 7 and the auxiliary battery 3, and each part of the control board 21 based on the auxiliary battery voltage The relay harnesses 26 _a and 26 _b connected to the connectors 17 _a and 17 _b of the driver board 11 are provided.
The transformer 16 provided on the driver board 11 and the transformer 25 provided on the control board 21 are arranged so as to be shifted in the surface direction of the power semiconductor substrate 12. As a result, the power semiconductor unit 5 can be reduced in size while preventing the transformers from interfering with each other physically and electromagnetically.
Further, as described above, in the power semiconductor unit according to the present invention, the driver circuit and the signal generation circuit are driven by the auxiliary battery voltage supplied through the connector 27. Accordingly, only one connector 27 is required, and it is not necessary to increase the size of the power semiconductor unit 5 in order to prevent a plurality of connectors from interfering with each other.

The PWM signal generated by the control board 21 and the auxiliary battery voltage supplied from the auxiliary battery 3 are transmitted to the driver board 11 via the relay harnesses 26 _a and 26 _b . Further, a fail signal is transmitted from the driver board 11 via the relay harnesses 26 _a and 26 _b .

FIG. 9A is an external perspective view of the power semiconductor unit 5 with the unit cover 24 removed as viewed from the output terminal side.
Output bus bars 29 _{U to} 29 _W are connected to the output terminals 18 _U to 18 _W of the respective phases provided on the side surface of the power semiconductor module 10. The output bus bars 29 _{U to} 29 _W are shaped so that the current paths formed by the bus bars are orthogonal to the driver board 11 and the control board 21 arranged in parallel to each other.

The shield plate 23 is bent at its end, and at least a part of the space on the opposite surface side (back surface side) of the control board 21 is covered by the bent end of the shield plate 23. Specifically, bent so as to block between the control board 21 and the V-phase output bus bars 29 _V. Thus, noise radiated from the V-phase output bus bar 29 _V in accordance with the V-phase output current, it is prevented from being superimposed on the control board 21. As a result, malfunction of the CPU 30 mounted on the surface of the control board 21 can be prevented.
The shield plate 23 is not bent for the U phase and the W phase provided with the current sensors 22 _U and 22 _W. This is because the magnetic field generated around the output bus bars 29 _U and 29 _W is confined by the electromagnetic steel sheet wound around the hollow opening.
In addition, the length by which the bent end of the shield plate 23 is extended includes the output terminals 18 _U to 18 _W of each phase of the power semiconductor module 10 and the input bus bars 19 _{UP to} 19 _{WP and} 19 _{UN of} each phase. It is desirable that the distance from 19 _WN and the output bus bars 29 _{U to} 29 _{W of} each phase be determined so as to be separated by a spatial insulation distance required by the IEC standard or the like.

FIG. 9B is an external perspective view of the power semiconductor unit 5 with the unit cover 24 removed, as viewed from the input terminal side.
The power semiconductor module 10 and the control board module 20 are connected by input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN . The input bus bars for each phase (for example, U-phase input bus bars 19 _UP and 19 _UN ) are provided so as to partially overlap each other. The shapes of the input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN will be described in detail later.

Also on the input terminal side, the shield plate 23 is bent to block between the control board 21 and the input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _WN of each phase. This prevents noise radiated from the input bus bars 19 _{UP to} 19 _WP and 19 _{UN to} 19 _{WN of} each phase from being superimposed on the control board 21.
Thus, in the power semiconductor unit according to the present invention, the shielding effect is enhanced by forming the shield plate 23 in an inverted U shape bent at the input side and the output side.

FIG. 10A is an exploded perspective view of the control board 21 and the shield plate 23 as viewed from the front side.
On the front surface side (non-facing surface side) of the control board 21, there are provided an arithmetic circuit (for example, CPU 30) and a signal processing circuit (for example, signal processing IC 31) that operates with a clock of several tens MHz such as a resolver signal processing IC. It is done. The CPU 30 refers to the instantaneous values of the U-phase and W-phase output currents obtained by the current sensors 22 _U and 22 _W on the back surface side, that is, the output set value of the load input from the outside via the connector 27, that is, Based on the torque command value (torque value to be output to the load) input from the ECU, a control signal (PWM signal) for the driver circuit is generated. In this specification, the wiring formed on the surface side of the CPU 30, the signal processing IC 31, and the control board 21 is collectively referred to as a “signal generation circuit”.
In the power semiconductor unit according to the present invention, since the signal generation circuit is provided on the non-facing surface side (surface side) of the power semiconductor module 10, the distance from the power semiconductor module 10 can be increased, and the power Noise generated from the semiconductor module 10 is blocked by the control board 21 and can be prevented from being superimposed on the signal generation circuit.

  The CPU 30 and the signal processing IC 31 are covered with a shield plate 23 disposed on the surface side of the control board 21. The shield plate 23 is appropriately pressed for reinforcement. The height of the space formed between the shield plate 23 and the control board 21 is about 5 [mm].

FIG. 10B is a schematic cross-sectional view taken along line BB in a state where the control board 21 and the shield plate 23 of FIG.
The control board 21 is a multilayer wiring board provided with four wiring layers of L1 layer to L4 layer. In the L1 layer which is the uppermost layer, wiring for digital signals and analog signals related to the CPU 30 and the signal processing IC 31 is formed. The L2 layer is mainly a GND layer formed over almost the entire surface of the control substrate 21. The GND layer can shield noise from the power semiconductor module 10 located below the control board module 20, and can reduce the impedance of the wiring formed in the L1 layer to improve noise resistance.
In the L3 layer, wiring mainly related to the power supply is formed. In the L4 layer, wiring mainly related to the transformer 25, the connector 27, and the current sensors 22 _U and 22 _W is formed.

After all, the signal generation circuit provided on the front surface side (non-opposing surface side) of the control board 21 is sandwiched between the shield plate 23 and the GND layer covering the front surface side and the side surface, and is electromagnetically and electrostatically shielded. .
Thus, in the power semiconductor unit according to the present invention, noise due to switching of the power semiconductor module 10 and a large current flowing through the input bus bars 19 _{UP to} 19 _WP , 19 _{UN to} 19 _WN , and the output bus bars 29 _{U to} 29 _W of each phase. Can be prevented from being superimposed on the signal generation circuit provided on the front surface side (non-opposing surface side) of the control board 21.

FIG. 11B is a cross-sectional view taken along line BB of the power semiconductor unit 5 shown in FIG.
As shown in FIG. 11B, the driver board 11 of the power semiconductor module 10 and the control board 21 of the control board module 20 are arranged substantially parallel to each other at a certain distance. The distance between the driver board 11 and the control board 21 is determined based on the heights of the current sensors 22 _U and 22 _{W that} are the tallest among the various components provided on the control board 21 and the driver board 11. Since the current sensors 22 _U and 22 _W are provided at the end of the control board 21, the transformers 16 and 25 are arranged in the space area between the driver board 11 and the control board 21, and the space area is effectively used. Be utilized.

  Next, the shapes of the input bus bar and the output bus bar used in the power semiconductor unit according to the present invention will be described in detail with reference to FIGS.

FIG. 12A is a perspective view showing input bus bars 19 _UP and 19 _UN having a “straight structure” used in the power semiconductor unit 5 according to the present invention. FIG. 12B shows the “cross structure” input bus bars 19 ′ _{UP and} 19 ′ _UN prepared for the comparative experiment. FIGS. 12A and 12B show the structure of the U-phase input bus bar as an example, but in the comparative experiment shown below, the V-phase and W-phase input bus bars have the same structure. did.

The input bus bars 19 _UP , 19 _UN , 19 ′ _UP , and 19 ′ _UN have a width of 15 [mm], a thickness of 1.5 [mm], and a height of 35 [mm], respectively, and f = 1 [kHz]. The wiring inductances are about 16 [nH] (straight structure) and about 20 [nH] (cross structure), respectively.

In the inverter unit 1 using the straight structure input bus bar (see FIG. 5) and the inverter unit 1 using the cross structure input bus bar, the effective current of the traveling motor 6 is continuously changed from 0 to 150 [A _rms ]. An experiment was conducted as to whether or not noise was superimposed on the analog signal wiring related to the motor temperature obtained by the thermistor.
In this experiment, the voltage of the main battery 2 was set to 365 [V]. Further, in order to clarify the influence of noise radiated from the input bus bar, the experiment was performed by removing the shield plate 23 covering the surface side of the control board 21.

FIG. 13A shows the experimental results of the inverter unit 1 using the straight structure input bus bars 19 _UP and 19 _UN , and FIG. 13B shows the inverter using the cross structure input bus bars 19 ′ _UP and 19 ′ _UN. 6 is a graph showing an experimental result of unit 1; The vertical axis of each graph is obtained by taking an analog signal relating to the motor temperature obtained by the thermistor into the CPU 30 and converting it into digital data. In this experiment, since the thermistor is used to detect the motor temperature, the digital data of each graph decreases as the temperature rises (time elapses).

As shown in FIG. 13A, in the input bus bars 19 _UP and 19 _UN having a straight structure, no superposition of noise is observed in the wiring of the analog signal related to the motor temperature provided in the L1 layer. On the other hand, as shown in FIG. 13B, irregular noise is superimposed on the input bus bars 19 ′ _UP and 19 ′ _UN having a cross structure.

The experimental results will be discussed with reference to FIG. FIG. 14A is a diagram illustrating a current path formed by an input bus bar having a straight structure.
The current supplied from the main battery 2 flows from the upper part to the lower part of the input bus bar 19 _UP via the P terminals 8 _P2 and 8 _P1 of the smoothing capacitor 4 and flows to the collector of the U-phase power semiconductor element 14 _U. Entered. This current is output from the emitter of the U-phase power semiconductor element 14 _U , flows through the input bus bar 19 _UN from the bottom to the top, and passes through the N terminals 8 _N2 and 8 _N1 of the smoothing capacitor 4 to the main battery. Go back to 2.

As apparent from FIG. 14A, in the straight structure, the current flowing through the input bus bar 19 _UP and the current flowing through the input bus bar 19 _UN are opposite in both the x direction and the y direction. The magnetic flux is completely canceled or weakened.
In addition, since the current component in the x direction is small in the straight structure, it is considered that the magnetic flux due to the current in the x direction is reduced from interlinking with the wiring of the control board 21 and noise is hardly superimposed.

On the other hand, the current path formed by the cross-structured input bus bar is as shown in FIG.
As is clear from FIG. 14B, in the cross structure, the current in the x direction flowing through the input bus bar 19 _UP and the current in the x direction flowing through the input bus bar 19 _UN flow in the same direction, and the magnetic flux caused by these currents is strengthened. There is a matching part. The magnetic flux generated by the current in the x direction is linked to the wiring of the control board 21 and greatly affects the signal transmitted by the wiring.
That is, in the cross structure input bus bar, the flux linkage changes according to the instantaneous large current flowing through the inverter, and noise is superimposed on the wiring of the control board 21, resulting in a temperature as shown in FIG. It seems that data abnormality occurred.

12 to 14, the structure of the input bus bar is compared, but the same can be said for the output bus bar. In other words, the output bus bars 29 _{U to} 29 _W have current paths in a direction (= y direction) orthogonal to the driver board 11 and the control board 21 arranged in parallel to prevent noise from being superimposed on the wiring of the control board 21. It is desirable that the shape be formed.

  As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to the said structure.

For example, the power semiconductor unit according to the present invention can be applied not only to an inverter that drives a load such as a motor but also to a converter. In this case, AC power is supplied to the input terminal via the input bus bar from the multiphase AC power source connected to the input side to the power semiconductor unit. The power semiconductor unit outputs DC power to the smoothing capacitor connected to the output side while referring to the input current value of each phase obtained by the current sensor. The signal generation circuit generates a control signal based on the input current value obtained by the current sensor.
As described in the inverter unit 1, the current sensor has a hollow port extending in the normal direction of the power semiconductor substrate, and the input bus bar extends in the normal direction through the hollow port. . The configuration of the power semiconductor unit is almost the same as the configuration shown in FIGS.

  The power semiconductor unit according to the present invention is a three-phase AC-DC-AC converter (see FIG. 2) configured by combining a power semiconductor unit that operates as an inverter and a power semiconductor unit that operates as a converter. It can also be applied.

In the three-phase AC-DC-AC converter 50 shown in FIG. 15, the power semiconductor unit 5 _C that operates as a three-phase PWM rectifier and the power semiconductor unit 5 _I that operates as a three-phase inverter are connected to the smoothing capacitor 4. .
The AC power is input to the output terminals 29 _{U to} 29 _W of the power semiconductor unit 5 _C via the three-phase cable 51 and the reactor 52. AC voltage (AC100V or 200V, 50 Hz or 60Hz) while stored the magnetic energy in the reactor 52, (specifically, the power semiconductor module 10 _C included in the power semiconductor unit _{5 C)} power semiconductor unit _{5 C} to the DC voltage It is converted and stored in the smoothing capacitor 4.

In the three-phase AC-DC-AC converter 50 shown in FIG. 15, the smoothing capacitor 4 is configured by connecting a plurality of electrolytic capacitors in parallel, and has a capacitance of several thousand to several tens of thousands μF. According to the smoothing capacitor 4, the instantaneous power failure or load fluctuation, DC when the bus voltage varies also, the power semiconductor unit 5 _I control which operates as a three-phase inverter can be stabilized.
DC bus voltage which is stabilized by the power semiconductor module 10 _I, is converted into a predetermined amplitude, the three-phase alternating current waveform having a predetermined frequency, is fed to the load through a reactor 53.

In the three-phase AC-DC-AC converter shown in FIG. 15, the constituent elements are arranged in a straight line, but can be freely laid out, for example, folded back into a U shape.
The power semiconductor unit according to the present invention can be easily applied not only to a three-phase inverter and converter but also to a single-phase or multi-phase inverter and converter exceeding three phases.

It is a figure which shows the circuit structure of an inverter unit. It is a figure which shows the circuit structure of a three phase type AC-DC-AC converter. It is a block diagram which shows the structure of the conventional inverter unit. It is a block diagram which shows the structure of the conventional inverter unit. It is an external appearance perspective view of the inverter unit provided with the power semiconductor unit which concerns on this invention. It is a power semiconductor unit concerning the present invention, and (A) is an appearance perspective view and (B) is an exploded perspective view. It is a power semiconductor module concerning the present invention, and (A) is an appearance perspective view and (B) is an exploded perspective view. It is a control board module which concerns on this invention, Comprising: (A) is an external appearance perspective view, (B) is an exploded perspective view. FIG. 2A is an external perspective view seen from the output terminal side, and FIG. 4B is an external perspective view seen from the input terminal side. FIG. It is a figure which shows the positional relationship of the control board and shield plate which concern on this invention, Comprising: (A) is a disassembled perspective view, (B) is sectional drawing in line BB. It is a power semiconductor unit concerning the present invention, and (A) is a top view and (B) is a sectional view in line BB. It is a perspective view of the input bus bar of each phase, (A) is an input bus bar of the straight structure concerning the present invention, and (B) is an input bus bar of the cross structure for comparison. It is a graph of the experimental result about whether noise is superimposed, Comprising: (A) is a graph at the time of applying the input bus bar of a straight structure, (B) is a graph at the time of applying the input bus bar of a cross structure. . It is a figure which shows the current path of an input bus bar, (A) is a current path of the input bus bar of a straight structure, (B) is a current path of the input bus bar of a cross structure. 1 is an external perspective view of a three-phase AC-DC-AC converter to which a power semiconductor unit according to the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inverter unit 2 Main battery 3 Auxiliary battery 4 Smoothing capacitor 5, 5 _I , 5 _C power semiconductor unit 6 Traveling motor 7 Motor position detection resolver 8 _P1 , 8 _P2 P terminal 8 _N1 , 8 _N2 N terminal 10 Power semiconductor module 10 _C power semiconductor module (three-phase PWM rectifier)
10 _I power semiconductor module (three-phase inverter)
11 Driver Board 12 Power Semiconductor Board 13 Shield Plate 14 _U , 14 _V , 14 _W Power Semiconductor Element (IGBT)
15 _U , 15 _V , 15 _W FWD element 16 Transformer 17 _a , 17 _b Connector 18 _U U-phase output terminal 18 _V V-phase output terminal 18 _W W-phase output terminal 19 _UP , 19 _UN U-phase input bus bar 19 _VP , 19 _VN V-phase input bus bar 19 _WP , 19 _WN W-phase input bus bar 20 Control board module 21 Control board 22 _U U-phase current sensor 22 _W W-phase current sensor 23 Shield plate 24 Unit cover 25 Transformers 26 _a , 26 _b Relay harness 27 Connector 28 IC
29 _U U phase output bus bar 29 _V V phase output bus bar 29 _W W phase output bus bar 30 Arithmetic circuit 31 Signal processing IC
32 Radiator 33 Radiating fin 50 Three-phase AC-DC-AC converter 51 Three-phase cable 52 Reactor 53 Reactor

Claims (9)

A power semiconductor unit that converts direct current power into alternating current power using a power semiconductor element and outputs it to a load to be driven.
An input terminal to which the DC power is fed;
An output terminal connected to the load;
A power semiconductor substrate on which the power semiconductor element is provided, and a driver that is arranged in parallel with a predetermined interval on the surface side of the power semiconductor substrate and drives the power semiconductor element based on an input control signal A power semiconductor module having a driver board provided with a circuit;
A current sensor for detecting a current value of a current output from the power semiconductor module to the load;
Directly above the power semiconductor module, disposed substantially parallel to the driver substrate, and having a facing surface facing the power semiconductor module and a non-facing surface that is the back surface of the facing surface, detected by the current sensor A control board provided with a signal generation circuit for generating the control signal based on the current value;
A shield plate covering the space on the non-facing surface side and the side surface of the control board;
With
The signal generation circuit is provided on the non-facing surface of the control board, and the current sensor is provided on the facing surface of the control board ,
The control board is a multilayer wiring board having at least one GND layer;
A power semiconductor unit characterized in that noise emitted from the power semiconductor module toward the signal generation circuit is shielded by sandwiching the signal generation circuit between the shield plate and the GND layer . The output terminal and the load are connected by an output bus bar,
The current sensor has a hollow port extending in a normal direction of the power semiconductor substrate,
The power semiconductor unit according to claim 1, wherein the output bus bar extends in the normal direction through the hollow port. The DC power is fed to the input terminal via an input bus bar,
The power semiconductor unit according to claim 2, wherein the input bus bar is disposed so as to face the output bus bar and extends in the normal direction. A power semiconductor unit that uses a power semiconductor element to convert AC power input from an AC power source into DC power, and outputs the DC power.
An input terminal to which the AC power is fed;
An output terminal for outputting the DC power;
A power semiconductor substrate on which the power semiconductor element is provided, and a driver that is arranged in parallel with a predetermined interval on the surface side of the power semiconductor substrate and drives the power semiconductor element based on an input control signal A power semiconductor module having a driver board provided with a circuit;
A current sensor for detecting a current value of a current input from the AC power source to the power semiconductor module;
Directly above the power semiconductor module, disposed substantially parallel to the driver substrate, and having a facing surface facing the power semiconductor module and a non-facing surface that is the back surface of the facing surface, detected by the current sensor A control board provided with a signal generation circuit for generating the control signal based on the current value;
A shield plate covering the space on the non-facing surface side and the side surface of the control board;
With
The signal generation circuit is provided on the non-facing surface of the control board, and the current sensor is provided on the facing surface of the control board ,
The control board is a multilayer wiring board having at least one GND layer;
A power semiconductor unit characterized in that noise emitted from the power semiconductor module toward the signal generation circuit is shielded by sandwiching the signal generation circuit between the shield plate and the GND layer . The AC power is fed to the input terminal via an input bus bar,
The current sensor has a hollow port extending in a normal direction of the power semiconductor substrate,
5. The power semiconductor unit according to claim 4, wherein the input bus bar extends in the normal direction through the hollow port. The DC power is output from the output terminal via an output bus bar,
6. The power semiconductor unit according to claim 5, wherein the output bus bar is disposed so as to face the input bus bar and extends in the normal direction. The shield plate is bent at the end,
The at least part of the space formed between the control board and the driver board is covered with a bent end of the shield plate. Power semiconductor unit. Transformers for supplying power to the signal generation circuit and the driver circuit are provided on the facing surface of the control board and the surface of the driver board facing the control board, respectively, and the transformer is the power semiconductor substrate. The power semiconductor unit according to claim 1, wherein the power semiconductor units are arranged so as to be shifted from each other in the plane direction so that the transformers do not interfere with each other. One connector for connecting to an external power supply is provided on the facing surface of the control board, and the driver circuit and the signal generation circuit are driven by a voltage supplied from the outside through the connector. A power semiconductor unit according to any one of claims 1 to 8.

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