JP2010220286A - Motor control device and vehicle system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor control device capable of discharging the charges accumulated in a capacitor without installing a discharging resistor or an additional circuit for discharging, and to provide a vehicle system. <P>SOLUTION: The motor control device has a structure in which a plurality of arms formed by connecting upper transistors and lower transistors in series are connected in parallel between a power supply and a ground, and is connected to inverters in which intermediate points of the plurality of arms are connected to terminals of each phase of the motor coil. The motor control device controls switching of the upper transistors and the lower transistors to drive the motor. The motor control device has a discharging function for causing the motor coil to consume the charges accumulated in a capacitor disposed between the power supply and a ground by turning on each combination having the upper transistor and the lower transistor which are activated while being disconnected from the battery and disposed in the different arms. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a motor control device and a vehicle system, and more particularly to a motor control device and a vehicle system that drive a motor via an inverter.

  In a vehicle that runs on an AC motor such as an electric vehicle or a hybrid vehicle, a capacitor is disposed between the power source and the ground in order to suppress fluctuations in the voltage supplied from the battery to the inverter. Further, when performing inspection or repair, it is necessary to discharge the electric charge remaining in the capacitor, and a resistor (discharge resistor) is provided between both electrodes of the capacitor.

  Japanese Patent Application Laid-Open No. H10-228561 discloses a configuration that can omit this discharge resistance. Specifically, in a power supply circuit that smoothes a DC voltage from a main power supply by a smoothing capacitor and supplies the same to an inverter and controls switching of a switching transistor in the inverter to output a predetermined AC current, at least one switching in the inverter A drive means for adjusting the magnitude of the control voltage applied to the control terminal of the transistor, and a current for controlling the drive means to operate the corresponding switching transistor in the active region and limiting the current flowing therethrough to a predetermined value Limiting means, and when the output of the DC voltage from the main power supply is turned off, the current limiting means controls the control voltage of the switching transistor so that a predetermined discharge current flows therethrough and the charge stored in the smoothing capacitor A power supply circuit characterized in that it consumes power is disclosed

Japanese Patent Laid-Open No. 9-201065

  However, the power supply circuit of Patent Document 1 needs to be provided with an additional circuit called a current limiting unit, and cannot be greatly reduced in cost and circuit scale. In addition, the power supply circuit of Patent Document 1 turns on the upper and lower arm pairs in the discharge resistance inverter to flow current, and there is a problem that the transistor generates heat. By limiting the discharge current, the amount of heat generated by the transistor can be suppressed, but it takes a certain amount of time to complete the discharge.

  The present invention has been made in view of the circumstances described above, and the object of the present invention is to discharge the electric charge stored in the capacitor without providing the above-described discharge resistance or additional circuit for discharge. It is an object of the present invention to provide a motor control device and a vehicle system that can be used.

  According to the first aspect of the present invention, a plurality of arms (branch lines) in which an upper transistor and a lower transistor are connected in series between a power source and a ground are connected in parallel, and the midpoint of the plurality of arms is connected to a motor coil. It is connected to an inverter connected to each phase terminal, and is a motor control device that drives a motor by controlling switching of the upper transistor and the lower transistor, and is activated in a state where the connection with the battery is disconnected, By turning on a combination of an upper transistor and a lower transistor arranged in different arms, a discharge function for consuming the electric charge accumulated in a capacitor arranged between the power supply and the ground in the motor coil is provided. A motor control device and a vehicle system equipped with the motor control device are provided.

  According to the present invention, the discharge resistance and the additional circuit for discharge can be omitted, and cost reduction and space saving can be realized. This is because the motor coil is used to consume the electric charge stored in the capacitor.

It is a figure showing the structure of the motor control apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart showing operation | movement of the motor control apparatus which concerns on the 1st Embodiment of this invention. It is a figure showing the combination of the transistor which can comprise the circuit which can be discharged in the motor control apparatus which concerns on the 1st Embodiment of this invention. It is a figure for demonstrating the effect | action of the motor control apparatus which concerns on the 1st Embodiment of this invention. It is another figure for demonstrating the effect | action of the motor control apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart showing operation | movement of the motor control apparatus which concerns on the 2nd Embodiment of this invention.

  Next, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a motor control device according to a first embodiment of the present invention. Referring to FIG. 1, a battery 10, an inverter 20, a control unit 30 that supplies necessary signals to the inverter 20, and a motor 40 are shown. By adopting a configuration in which the torque output from the motor 40 is transmitted to the wheels, a vehicle system that travels with electric power stored in the battery can be configured.

  The battery 10 is a DC power source connected to the inverter 20 via relays RY1 and RY2 that are opened during non-operation such as when the ignition is turned off.

  The inverter 20 has three arms of U-phase, V-phase, and W-phase in which an upper transistor (eg, Tr1) and a lower transistor (eg, Tr2) are connected in series. The point) is connected to each phase end of the three motor coils of the motor 40. Between the power supply of the inverter 20 and the ground, a capacitor (capacitor) 21 that absorbs fluctuations in the DC voltage supplied from the battery 10 is disposed.

  Each of the transistors Tr1 to Tr6 is configured by an IGBT (Insulated Gated Bipolar Transistor), and a diode that circulates current from the emitter side to the collector side is disposed between each collector and emitter.

  The control unit 30 switches the transistors Tr1 to Tr6 according to the position of the rotor of the motor 40, controls the phase of the current supplied to the motor 40, and is controlled by an ECU (electronic control unit) that drives the motor 40. Composed. In addition, the control unit 30 in the present invention has a function of executing a discharge process of charges accumulated in the capacitor 21 described later. Specific operations will be described in detail later.

  The motor 40 is a three-phase AC permanent magnet motor having a rotor using a permanent magnet inside a motor coil (stator coil). As such a motor, for example, a motor having an IPM (Interior Permanent Magnet) structure in which a permanent magnet is embedded in a rotor is known.

  Next, the operation of this embodiment will be described in detail with reference to the drawings. FIG. 2 is a flowchart showing an operation flow of the motor control device according to the first embodiment of the present invention.

  Referring to FIG. 2, first, when the control unit 30 detects that the ignition switch (IG switch) is turned off (“Yes” in step S001), the control unit 30 opens the relays RY1 and RY2, The power supply from the battery 10 to the inverter 20 is cut off (step S002).

  Subsequently, the control unit 30 turns on a predetermined transistor from the transistors Tr1 to Tr6 and forms a circuit for supplying current from the capacitor 21 to the motor coil (step S003; switching start). Since there are 12 combinations of transistors to be turned on as shown in FIG. 3, an appropriate one may be selected from these. The 12 patterns in FIG. 3 can be determined by selecting any one of the upper and lower transistors of two or more different arms.

  For example, when the transistors Tr1, Tr5, Tr6 having the first pattern in FIG. 3 are turned on, a discharging circuit is formed as shown by the thick line in FIG. Power is consumed.

  Further, for example, when the transistors Tr1 and Tr5 having the second pattern in FIG. 3 are turned on, a discharging circuit is formed as shown by a thick line in FIG. Electricity is consumed.

  Thereafter, the control unit 30 confirms the voltage (V1-V2) between the power source and the ground of the inverter 20 at a predetermined time interval (step S004), and the power source-ground (V1-V2) of the inverter 20 is constant. When the voltage value drops ("Yes" in step S004), the transistor switching control is terminated (step S005).

  Thereafter, the control unit 30 performs a power-off operation (step S006).

  As described above, according to the present embodiment, the electric charge accumulated in the capacitor 21 can be consumed by the motor coil without providing the inverter 20 with a discharge resistor. For example, when the capacity of the capacitor 21 is 4400 μF and the voltage of the battery 10 is 400 V, the accumulated charge can be estimated as 1.76 coulombs. If the discharge current at this time is constant at 300 A, the discharge can be completed in 5 ms.

[Second Embodiment]
Next, a second embodiment of the present invention will be described in detail with reference to the drawings. The present embodiment has substantially the same configuration as that of the first embodiment shown in FIG. 1, and only the method for detecting the completion of discharge is different. Therefore, the following description will focus on the differences.

  FIG. 6 is a flowchart showing the operation of the motor control device according to the second embodiment of the present invention. The difference from the flowchart of FIG. 2 showing the operation of the first embodiment is that the end of switching control is determined not by the voltage between the power supply and ground (V1-V2) of the inverter 20, but by the elapsed time from the start of switching control. This is the point that I did in.

  As described above, since the capacity of the capacitor 21 and the voltage of the battery 10 are known, the discharge completion time is estimated using them, and it is determined that a fixed time has elapsed in step S104 of FIG. The switching control is automatically terminated.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and further modifications, replacements, and replacements may be made without departing from the basic technical idea of the present invention. Adjustments can be made.

10 Battery 20 Inverter 21 Capacitor
30 control unit 40 motor RY1, RY2 relay Tr1-Tr6 transistor

Claims (3)

A plurality of arms in which an upper transistor and a lower transistor are connected in series between a power source and a ground are connected in parallel, and connected to an inverter in which a middle point of each of the arms is connected to a terminal of each phase of a motor coil, A motor control device for driving a motor by controlling switching of a transistor and a lower transistor,
Activated with the battery disconnected and stored in a capacitor located between the power supply and ground by turning on the combination of upper and lower transistors located on different arms A motor control device having a discharge function for consuming electric charge by the motor coil.   The motor control device according to claim 1, wherein the combination of the upper transistor and the lower transistor is a combination in which one upper transistor or one lower transistor is selected for each arm.   A vehicle system equipped with the motor control device according to claim 1 or 2 and a motor driven by the motor control device.

Images