|
|
|
| United States Patent | 5569995 |
| Link to this page | http://www.wikipatents.com/5569995.html |
| Inventor(s) | Kusaka; Yasushi (Susono, JP);
Yamada; Eiji (Owariasahi, JP);
Kawabata; Yasutomo (Aichi-gun, JP) |
| Abstract | A method and an apparatus for driving and controlling a synchronous motor
using permanent magnets as its field system are herein disclosed. When a
rotational speed of the synchronous motor using the permanent magnets as
the field system is more than a base rotational speed, a current condition
computing section computes a field weakening reference current in
accordance with a battery voltage, a reference torque and a rotational
speed. An inverter performs the field weakening control of the the
synchronous motor using the permanent magnets as the field system in
accordance with the field weakening reference current sent from the
current condition computing section to prevent the deterioration of
efficiency and the deficiency of output due to the excessive or
insufficient field weakening current. The current condition computing
section determines optimum reference current by the use of a converged
battery voltage, when the battery voltage is converged to a constant value
after initial control. |
|
|
 |
Title Information  |
|
|
|
|
|
|
| Publication Date |
October 29, 1996 |
|
|
|
|
|
| Filing Date |
August 10, 1994 |
|
|
|
|
|
|
|
|
|
|
|
|
|
| Priority Data |
Aug 10, 1993[JP]5-198100
Oct 12, 1993[JP]5-254152
Feb 28, 1994[JP]6-030544 |
|
|
|
|
|
|
|
|
 |
|
 |
Title Information |
|
|
|
References |
|
|
| *references marked with an asterisk below are user-added references |
 |
U.S. References |
|
|
|
 |
|
|
|
U.S. References |
|
|
|
Foreign References |
|
|
|
|
|
|
|
|
Foreign References |
|
|
|
Other References |
|
|
|
|
|
|
|
|
Other References |
|
|
|
|
|
|
|
References |
|
|
|
|
|
|
| Market Size |
|
Estimate the gross annual revenues of the relevant market
sector:
|
| | |
| |
|
|
| Market Share |
|
Estimate the percentage of the relevant market sector this invention will capture:
|
| | |
| |
|
|
| Reasonable Royalty |
|
What percentage of gross sales should the inventor or assignee be paid?
|
| | |
| |
|
|
|
Public's "Guesstimation" of Royalty Value
|
| Market Size | N/A | [No votes] | | x | Market Share | N/A | [No votes] | | x | Reasonable Royalty | N/A | [No votes] |
| | N/A | |
| |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Market Review |
|
|
|
Technical Review |
|
|
|
Claims |
|
|
What is claimed is:
1. A driving and controlling apparatus for use in a drive unit having a
synchronous motor using permanent magnets as its field system which can be
excited by a field flux generated by the permanent magnets and a field
flux generated by a field current component of a primary current; a
battery as a source of power; and power conversion means for converting a
discharged power of the battery into alternating current, and then feeding
the alternating current as the primary current to the synchronous motor;
said apparatus comprising:
current control means for controlling the primary current of the
synchronous motor in accordance with a reference current; and
current condition determination means for determining the reference current
in accordance with a voltage of the battery so that the reference current
is minimized under predetermined conditions and at least partially
cancelling the field flux generated by the permanent magnets with the
field flux generated by the field current component so that a counter
electromotive force of the synchronous motor does not exceed the voltage
of the battery and so that the field flux generated by the field current
component has an magnitude corresponding to the voltage of the battery.
2. The driving and controlling apparatus according to claim 1 wherein the
current condition determination means has:
counter electromotive force judgment means for judging whether or not the
counter electromotive force of the synchronous motor exceeds the voltage
of the battery in accordance with an output state of the synchronous
motor;
means for determining the reference current so that the field flux
generated by the field current component is fixed to a certain value, when
it has been judged that the counter electromotive force does not exceed
the voltage of the battery; and
means for determining the reference current so that the counter
electromotive force of the synchronous motor does not exceed the voltage
of the battery and so that the field flux generated by the field current
component has the magnitude corresponding to the voltage of the battery,
when it has been judged that the counter electromotive force exceeds the
voltage of the battery.
3. The driving and controlling apparatus according to claim 2 wherein
the output state of the synchronous motor used to judge whether or not the
counter electromotive force of the synchronous motor exceeds the voltage
of the battery is a rotational speed of the synchronous motor; and
the current condition determination means judges that the counter
electromotive force of the synchronous motor exceeds the voltage of the
battery, when the rotational speed of the synchronous motor is higher than
a predetermined value, and judges that the counter electromotive force
does not exceed the voltage of the battery, when the rotational speed is
not higher than the predetermined value.
4. The driving and controlling apparatus according to claim 1 wherein
the reference current includes the reference field current representative
of a control target of the field current component of the primary current
and the reference torque current representative of a control target of the
torque current | | |
