Current detection apparatus and control apparatus of rotary electric machine

Patent metadata

Field	Value
Publication number	US-2017201201-A1
Application number	US-201615394165-A
Country	US
Kind code	A1
Filing date	Dec 29, 2016
Priority date	Jan 7, 2016
Publication date	Jul 13, 2017
Grant date	—

Abstract

In a current detection apparatus, an arm current detection unit detects each of at least first and second phase currents having respective amplitudes and flowing in a multiphase rotary electric machine based on a potential difference between input and output terminals of the corresponding one of first and second detection switches during the corresponding one of the first and second detection switches being on. A bus current detection unit detects each of at least bus-based first and second phase currents corresponding to the first and second phases of the multiphase rotary electric machine based on a current flowing through one of first and second buses. An amplitude correction unit corrects the first and second phase currents based on the bus-based first and second phase currents such that the amplitudes of the respective first and second phase currents match with each other.

First claim

What is claimed is:

1 . A current detection apparatus for application to a system including a direct-current power supply, an inverter including plural pairs of series-connected upper-arm switches and lower-arm switches, and a multi-phase rotary electric machine connected to the inverter, the upper- and lower-arm switches of each pair being connected to a corresponding one phase of the multi-phase rotary electric machine, an upper set of the upper-arm switches being connected to the direct-current power supply via a first bus, a lower set of the lower-arm switches being connected to the direct-current power supply via a second bus, first and second phase switches selected in one of the upper set of the upper-arm switches and the lower set of the lower-arm switches being respectively defined as first and second detection switches, the first and second phase switches corresponding to respective first and second phases of the multi-phase rotary electric machine, the current detection apparatus comprising:
an arm current detection unit configured to detect each of at least first and second phase currents having respective amplitudes and flowing in the multiphase rotary electric machine based on a potential difference between input and output terminals of the corresponding one of the first and second detection switches while the corresponding one of the first and second detection switches is on; a bus current detection unit configured to detect each of at least bus-based first and second phase currents corresponding to the first and second phases of the multiphase rotary electric machine based on a current flowing through one of the first and second buses; and an amplitude correction unit configured to correct the first and second phase currents detected by the arm current detection unit based on the bus-based first and second phase currents detected by the bus current detection unit such that the amplitudes of the respective first and second phase currents detected by the arm current detection unit match with each other.

2 . The current detection apparatus according to claim 1 , wherein:
the bus current detection unit includes a portion for measuring the current flowing through one of the first and second buses; and the amplitude correction unit is configured to correct the first and second phase currents detected by the arm current detection unit based on a temperature of the portion of the bus current detection unit in addiction to the bus-based first and second phase currents detected by the bus current detection unit.

3 . The current detection apparatus according to claim 1 , wherein:
the bus current detection unit is configured to sequentially detect peak values of the respective bus-based first and second phase currents; and the amplitude correction unit is configured to correct the first and second phase currents detected by the arm current detection unit based on: the peak values of the bus-based first and second phase currents detected by the bus current detection unit; and peak values of the first and second phase currents detected by the arm current detection unit.

4 . The current detection apparatus according to claim 3 , further comprising:
a gain calculation unit configured to divide the peak value of each of the bus-based first and second phase currents detected by the bus current detection unit by the peak value of the corresponding one of the first and second phase currents detected by the arm current detection unit, thus calculating a correction gain for each of the first and second phase currents detected by the arm current detection unit, wherein the amplitude correction unit is configured to multiply each of the first and second phase currents detected by the arm current detection unit by the correction gain for the corresponding one of the first and second phase currents, thus correcting the first and second phase currents detected by the arm current detection unit.

5 . The current detection apparatus according to claim 4 , wherein:
the multiphase rotary electric machine is a three-phase rotary electric machine having a third phase in addition to the first and second phases; the bus current detection unit is configured to detect, within an electrical angular range larger than 120 electrical degrees, the peak values of the bus-based first and second phase currents and a peak value of a bus-based third phase current based on the current flowing through one of the first and second buses, the bus-phased third current corresponding to the third phase of the multiphase currents; and the amplitude correction unit is configured to correct the first and second phase currents detected by the arm current detection unit based on the peak values of the respective bus-based first to third phase currents.

6 . The current detection apparatus according to claim 5 , further comprising:
a storage unit configured to store the correction gains for the respective first and second phase currents calculated by the gain calculation unit, wherein the amplitude correction unit is configured to correct the first and second phase currents based on the correction gains for the respective first and second phase currents stored in the storage unit during a start of the multiphase rotary electric machine.

7 . The current detection apparatus according to claim 1 , wherein the first and second detection switches are lower-arm switches selected in the lower set of the lower-arm switches.

8 . The current detection apparatus according to claim 1 , wherein the arm current detection unit is configured to detect the at least first and second phase currents based on the potential differences between the input and output terminals of the respective first and second detection switches while the first and second detection switches are simultaneously on.

9 . The current detection apparatus according to claim 1 , wherein each of the arm current detection unit and bus current detection unit comprises:
a pulse running circuit comprising:
a plurality of inverting circuits connected in series, each of the inverting circuits being configured to perform an inverting operation of inverting a logical value of an input signal to output an inverted signal, and to have a time of the inversion operation changing on a power supply voltage, the inverting circuits including a start inverting circuit configured such that the inverting operation thereof is externally controllable, the inverting circuits being configured to run a pulse signal in response to activation of the start inverting circuit;
a signal input terminal connected to a common power supply line of the inverting circuits and configured such that an analog voltage signal based on a corresponding one of the first phase current, the second phase current, the bus-based first phase current, and the bus-phased second phase current is input thereto as a power supply voltage of each of the inverting circuits; a running position detection unit configured to detect a running position of the pulse signal in the pulse running circuit based on an output signal of each of the inverting circuits, thus generating digital data corresponding to the detected running position of the pulse signal; and a signal processing unit configured to capture the digital data generated by the running position detection unit, and generate, based on the captured digital data, binary digital data, the running position detection unit being configured to detect the running position of the pulse signal in the pulse running circuit at a timing when a predetermined time passes after start of running of the pulse signal by the pulse running circuit.

10 . A control apparatus for controlling a controll

Assignees

• Denso Corp

Inventors

• Aoki Yasuaki
• Matsuki Yosuke
• Yoshida Hideji

Classifications

• H02P21/22 Primary

  Current control, e.g. using a current control loop · CPC title

• H02P29/60

  Controlling or determining the temperature of the motor or of the drive (H02P29/02 takes precedence) · CPC title

• H02P2205/01

  Current loop, i.e. comparison of the motor current with a current reference · CPC title

• H02P2207/05

  Synchronous machines, e.g. with permanent magnets or DC excitation · CPC title

• H02P21/14

  Estimation or adaptation of machine parameters, e.g. flux, current or voltage · CPC title