JP2006308521A - Reactor application apparatus and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor application apparatus capable of measuring current flowing in a reactor with a small and lightweight constitution of reduced cost, and to provide a vehicle on which it is mounted. <P>SOLUTION: A boosting converter as the reactor application apparatus has the reactor L1. The reactor L1 comprises a reactor coil 52, a reactor core 54, and a current detection section 58 for detecting the strain produced in the reactor core 54 and measuring current flowing in the reactor coil. Preferably, the current detection section is fixed to the reactor core 54 and includes a piezoelectric element or strain gage for outputting an electric signal, according to the strain of the reactor core. The piezoelectric element or strain gauge is fixed to a section 56 sandwiched between two gaps G1 and G2 in the reactor core, and the reactor coil 52 is wound on the section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a reactor application device and a vehicle, and more particularly to current detection in a reactor application device.

  Japanese Patent Application Laid-Open No. 2000-88937 (Patent Document 1) discloses a magnetic field sensor that distorts a piezoelectric element by the elongation of the magnetostrictive element and converts it into a voltage. Also disclosed is that current detection is performed using the voltage output from the magnetic field sensor.

  Japanese Patent Laid-Open No. 9-281146 (Patent Document 2) discloses that current is measured by measuring magnetostriction using a magnetostrictive synthetic plate in which magnetostriction is generated by a magnetic field.

Japanese Patent Laid-Open No. Sho 63-313216 (Patent Document 3) discloses a technique for detecting a power source current by providing a gap in a core of a reactor and inserting a Hall element in the gap.
JP 2000-88937 A JP-A-9-281146 JP-A-63-331316 JP 2004-191312 A Japanese Utility Model Publication No. 5-77775

  In the techniques disclosed in Japanese Patent Laid-Open No. 2000-88937 (Patent Document 1) and Japanese Patent Laid-Open No. 9-281146 (Patent Document 2), it is necessary to prepare a separate magnetostrictive element for current measurement. For this reason, there was room for improvement in terms of cost.

  Further, using a Hall element for current detection as in the technique described in Japanese Patent Application Laid-Open No. 63-313216 (Patent Document 3) has the following problems.

  First, since the Hall element is a magnetic sensor, it must be magnetized to prevent magnetic interference. This is because when current measurement is performed using the Hall element exposed, there is a high possibility that magnetic interference will occur due to magnetism from other sources, and current measurement accuracy will not be achieved.

  On the other hand, collecting and measuring the magnetism generated from the measurement object by the magnetic flux collecting core makes the magnetic flux collecting core heavy and bulky, and increases the cost.

  An object of the present invention is to provide a reactor application device capable of measuring a current flowing through a reactor with a configuration that is small, lightweight, and cost-reduced, and a vehicle on which the reactor is mounted.

  In summary, the present invention is a reactor application device and includes a reactor. The reactor includes a reactor coil, a reactor core, and a current detection unit that detects a distortion generated in the reactor core and measures a current flowing through the reactor coil.

  Preferably, the current detection unit includes a piezoelectric element or a strain gauge that is fixed to the reactor core and outputs an electrical signal corresponding to the strain of the reactor core.

  More preferably, the piezoelectric element or the strain gauge is fixed to a portion sandwiched between two gaps in the reactor core, and a reactor coil is wound around the portion.

Preferably, the reactor is a reactor for storing energy of a voltage converter.
Preferably, the reactor is a reactor used in a current type inverter that drives a rotating electrical machine.

  Preferably, the reactor coil is a stator coil wound around a stator of a rotating electric machine, and the reactor core is a stator core.

  In another aspect, the present invention is a vehicle on which any one of the above reactor applied devices is mounted.

  According to the present invention, since the reactor core existing on the circuit is used, it is not necessary to prepare a separate magnetostrictive element for current measurement, and it is possible to realize cost reduction and space saving.

  Further, it is not necessary to collect magnetism, and furthermore, since the magnetic flux is not directly detected, it is possible to measure current without being affected by magnetic interference. Further, it is possible to reduce the size, weight, and cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

  FIG. 1 is a schematic diagram showing a configuration of a hybrid vehicle 1 to which a reactor application device of the present invention is applied.

  Referring to FIG. 1, hybrid vehicle 1 includes front wheels 20R and 20L, rear wheels 22R and 22L, an engine 2, a planetary gear 16, a differential gear 18, and gears 4 and 6.

  The hybrid vehicle 1 further includes a battery B disposed behind the vehicle, a booster unit 32 that boosts the DC power output from the battery B, an inverter 36 that transfers DC power between the booster unit 32, and the planetary gear 16. The motor generator MG1 coupled to the engine 2 via the main shaft and mainly generating electric power, and the motor generator MG2 whose rotation shaft is connected to the planetary gear 16 are included. Inverter 36 is connected to motor generators MG <b> 1 and MG <b> 2 and performs conversion between AC power and DC power from booster unit 32.

  Planetary gear 16 has first to third rotation shafts. The first rotation shaft is connected to engine 2, the second rotation shaft is connected to motor generator MG1, and the third rotation shaft is connected to motor generator MG2.

  A gear 4 is attached to the third rotating shaft, and the gear 4 drives the gear 6 to transmit power to the differential gear 18. The differential gear 18 transmits the power received from the gear 6 to the front wheels 20R and 20L, and transmits the rotational force of the front wheels 20R and 20L to the third rotating shaft of the planetary gear via the gears 6 and 4.

  Planetary gear 16 serves to divide the power between engine 2 and motor generators MG1, MG2. That is, if the rotation of two of the three rotation shafts of the planetary gear 16 is determined, the rotation of the remaining one rotation shaft is naturally determined. Accordingly, the vehicle speed is controlled by controlling the power generation amount of the motor generator MG1 and driving the motor generator MG2 while operating the engine 2 in the most efficient region, thereby realizing an overall energy efficient vehicle. Yes.

  Battery B, which is a DC power source, is composed of a secondary battery such as nickel metal hydride or lithium ion, for example, and supplies DC power to boost unit 32 and is charged by DC power from boost unit 32.

  Booster unit 32 boosts the DC voltage received from battery B and supplies the boosted DC voltage to inverter 36. Inverter 36 converts the supplied DC voltage into AC voltage, and drives and controls motor generator MG1 when the engine is started. Further, after the engine is started, AC power generated by motor generator MG1 is converted into DC by inverter 36, and converted to a voltage suitable for charging battery B by boosting unit 32, and battery B is charged.

  Inverter 36 drives motor generator MG2. Motor generator MG2 assists engine 2 to drive front wheels 20R and 20L. During braking, the motor generator performs a regenerative operation and converts the rotational energy of the wheels into electric energy. The obtained electric energy is returned to the battery B via the inverter 36 and the booster unit 32. Battery B is an assembled battery and includes a plurality of battery units B0 to Bn connected in series. System main relays 28 and 30 are provided between boost unit 32 and battery B, and the high voltage is cut off when the vehicle is not in operation.

  The control unit 14 controls the engine 2, the inverter 36, the booster unit 32, and the system main relays 28 and 30 in accordance with the driver's instructions and outputs from various sensors attached to the vehicle.

FIG. 2 is a circuit diagram showing the configuration of the boosting unit 32 in FIG.
Referring to FIG. 2, boosting unit 32 includes IGBT element Q1 having a collector connected to terminal TP and an emitter connected to node N2, and parallel to IGBT element Q1 with the direction from node N2 toward terminal TP as the forward direction. Diode D1 connected, IGBT element Q2 having a collector connected to node N2 and an emitter connected to terminal TN, and diode D2 connected in parallel with IGBT element Q2 with the direction from terminal TN toward node N2 as the forward direction Including.

  Boost unit 32 further includes a reactor L1 connected between nodes N1 and N2, and a smoothing capacitor C1 connected between node N1 and terminal TN. Node N1 is connected to the positive electrode of battery B via system main relay 28. Terminal TN is connected to the negative electrode of battery B via the wiring inside booster unit and system main relay 30.

FIG. 3 is a diagram showing the structure of reactor L1 in FIG.
Referring to FIG. 3, reactor L <b> 1 includes a reactor core 54 constituted by laminated electromagnetic steel plates and the like, and a reactor coil 52 in which a winding is wound around reactor core 54.

  One end of the reactor coil 52 is a node N1 in FIG. Reactor coil 52 has the other end connected to a node N2 in FIG. 2 and a connection point of an IGBT element that is a power semiconductor.

  The rear bore 54 is provided with gap portions G1 and G2. A current detector 58 including a piezoelectric element or a strain gauge is fixed to the reactor part 56 sandwiched between the gaps G1 and G2.

  Generally, a core used for a low-power reactor has no gap, but a core used for a reactor that handles high power has several gaps so as not to cause magnetic saturation.

4 is a cross-sectional view taken along line IV-IV in FIG.
Referring to FIGS. 3 and 4, the reactor core 54 is composed of laminated electromagnetic steel plates. However, the present invention is not limited to this, and the reactor core may be a dust core or a dust core. In the gap portions G1 and G2, for example, a sapphire plate or the like is inserted as a spacer.

  The current detection unit 58 includes a piezoelectric element or a strain gauge fixed to the surface of the reactor part 56 sandwiched between the gaps G1 and G2. This current detection unit is provided inside the winding of the reactor coil 52.

  The vicinity of the gap is a position suitable for measuring the expansion / contraction amount of the reactor core due to energization because the magnetic distortion is large due to the influence of the gap.

  When the reactor coil 52 is energized, distortion occurs in the reactor due to the magnetic field generated by energization. Specifically, the reactor core expands and contracts in the direction shown by the arrow in FIG. When a magnetic field is generated during energization, the reactor core contracts, and when the amount of energization decreases and the magnetic field weakens, the reactor core returns.

  If an element, for example, a piezoelectric element included in the current detection unit 58 is fixed to the surface of the reactor part 56, the distortion of the reactor is transmitted to the piezoelectric element, and a voltage corresponding to the distortion is output.

  The output voltage value is taken in by a CPU or the like and converted into a current value by a voltage-current value map held in a memory. In this way, the value of the current flowing through the reactor coil 52 can be measured.

  Note that the voltage-current value map is not necessarily required when the output voltage is used as it is for control or the like.

[Modification 1]
As a modification of the first embodiment, it is conceivable to detect the current of the reactor of the current type inverter with the configuration shown in FIG.

  FIG. 5 is a circuit diagram showing a configuration of a motor drive system in which a current type inverter is mounted.

  The motor drive system shown in FIG. 5 includes a battery 101, a reactor L2, a U-phase arm UA, a V-phase arm VA, a W-phase arm WA, and a motor 140.

  U-phase arm UA, V-phase arm VA, and W-phase arm WA are connected in parallel between one end of reactor L2 and the negative electrode of battery 101. The other end of the reactor L2 is connected to the positive electrode of the battery 101.

  U-phase arm UA includes IGBT elements 104 and 105 connected in series, and diodes 110 and 111 connected in parallel to IGBT elements 104 and 105, respectively. The cathode of diode 110 is connected to the collector of IGBT element 104, and the anode of diode 110 is connected to the emitter of IGBT element 104. The assortment of the diode 111 is connected to the collector of the IGBT element 105, and the anode of the diode 111 is connected to the emitter of the IGBT element 105.

  V-phase arm VA includes IGBT elements 106 and 107 connected in series, and diodes 112 and 113 connected in parallel with IGBT elements 106 and 107, respectively. The cathode of diode 112 is connected to the collector of IGBT element 106, and the anode of diode 112 is connected to the emitter of IGBT element 106. The cathode of diode 113 is connected to the collector of IGBT element 107, and the anode of diode 113 is connected to the emitter of IGBT element 107.

  W-phase arm WA includes IGBT elements 108 and 109 connected in series, and diodes 114 and 115 connected in parallel to IGBT elements 108 and 109, respectively. The cathode of diode 114 is connected to the collector of IGBT element 108, and the anode of diode 114 is connected to the emitter of IGBT element 108. The cathode of diode 115 is connected to the collector of IGBT element 109, and the anode of diode 115 is connected to the emitter of IGBT element 109.

An intermediate point of each phase arm is connected to each phase coil of motor 140.
The motor drive system having such a configuration may be mounted on the hybrid vehicle 1. In this case, the motor 140 in FIG. 5 corresponds to the motor generator MG1 or MG2 in FIG. 1, and the current type inverter constituted by the reactor L2, the U-phase arm UA, the V-phase arm VA, and the W-phase arm WA is shown in FIG. This corresponds to the inverter 36.

  According to the first modification, in order to detect the current of the reactor L2 in the configuration of FIG. 5, as shown in FIG. 3, a piezoelectric element or a strain gauge is fixed to the surface of the part 56 of the reactor 54 to detect the strain. Thus, a current value corresponding to this can be obtained.

[Modification 2]
FIG. 6 is a diagram for explaining the second modification.

  Referring to FIG. 6, the present invention can be used to measure the current flowing in stator coils UL, VL, WL included in motor 150. U-phase coil UL is connected between terminal UT and the middle point. Coil VL is connected between terminal VT and the middle point. Coil WL is connected between terminal WT and the midpoint.

  In such a configuration, if the configuration shown in FIGS. 3 and 4 is adopted for the stator core around which the coils UL, VL, and WL are wound, the motor current can be measured.

  As described above, according to the embodiment of the present invention, it is possible to measure the current supplied to the reactor coil by detecting the magnetostriction of the reactor core. With such a configuration, since it is not a magnetic sensor such as a Hall element, it is not necessary to take measures against magnetic interference, and since a magnetic collecting core is unnecessary, a small and lightweight reactor application device can be provided.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is the schematic which shows the structure of the hybrid vehicle 1 with which the reactor application apparatus of this invention is applied. FIG. 2 is a circuit diagram showing a configuration of a boost unit 32 in FIG. 1. It is the figure which showed the structure of the reactor L1 in FIG. It is sectional drawing in IV-IV in FIG. It is a circuit diagram which shows the structure of the motor drive system carrying a current type inverter. It is a figure for demonstrating the modification 2. FIG.

Explanation of symbols

  1 hybrid vehicle, 2 engine, 4, 6 gear, 14 control unit, 16 planetary gear, 18 differential gear, 20R, 20L front wheel, 22R, 22L rear wheel, 28, 30 system main relay, 32 boost unit, 36 inverter, 52 reactor Coil, 54 reactor, 58 current detector, 101, B battery, B0-Bn battery unit, 104-109, Q1, Q2 IGBT element, 110-115, D1, D2 diode, 140, 150 motor, C1 capacitor, G1 , G2 Gap, L1, L2 reactor, MG1, MG2 Motor generator, TN, TP terminal, UA U-phase arm, VA V-phase arm, WA W-phase arm, UL, VL, WL coil, UT, VT, WT terminal.

Claims (7)

A reactor, and the reactor is
A reactor coil;
With Reach Turkey,
A reactor application device, comprising: a current detection unit that detects distortion generated in the reactor core and measures a current flowing through the reactor coil. The current detector is
The reactor application device according to claim 1, comprising a piezoelectric element or a strain gauge that is fixed to the reactor and outputs an electric signal corresponding to the strain of the reactor. The piezoelectric element or the strain gauge is fixed to a portion sandwiched between two gaps in the reactor core,
The reactor application device according to claim 2, wherein the reactor coil is wound around the portion.   The reactor application apparatus according to any one of claims 1 to 3, wherein the reactor is a reactor for storing energy of a voltage converter.   The reactor application device according to any one of claims 1 to 3, wherein the reactor is a reactor used in a current-type inverter that drives a rotating electrical machine. The reactor coil is a stator coil wound around a stator of a rotating electrical machine,
The reactor application device according to claim 1, wherein the reactor core is a core of the stator.   A vehicle on which the reactor applied device according to any one of claims 1 to 6 is mounted.

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