JPS6231381A - Rotor angle detector of synchronous motor - Google Patents

Abstract

PURPOSE:To always obtain a rotor angle by storing a position data from a position detector for detecting the rotating position of a rotor, and calculating and storing the data to the rotor angle from the stored data. CONSTITUTION:Position data from a 1X resolver 32 and 10X resolver 33 coupled with the rotor shaft 48 of a synchronous motor 31 are input through a selector 34, a waveform shaper 35 and a phase synchronizer 52 to an incremental/ decremental counter 36. A CPU 37 obtains the position data corresponding to the rotor angle of the motor 31 from the counted value of the counter 36. The data are supplied to a latch circuit 38, and latched. The data latched by the latch circuit 38 are loaded to the counter 36.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a rotor angle detection device for a synchronous motor, and in particular, to a device for detecting a rotor angle of a synchronous motor so that position data, which is dependent on the rotor angle of a synchronous motor, can be directly read out from a position counter or the like. related to what was done.

(Background Art and its Problems) When controlling the position of a synchronous motor, it is first necessary to know the rotor angle of the #A motor at the time of startup.

In this case, if an LX resolver (or a detector equivalent to this) and a multi-pole resolver are used as detectors, the rotor angle can be calculated with high precision by calculating the position data obtained from these resolvers with a CPU, etc. It is possible to do so.

However, these resolvers are the same! Even if it is possible to make the angles of the resolver's rotor and the rotor of the same M motor match each other when installed on a TII motor, the position data of a multipolar resolver and the rotor angle of a synchronous motor are generally 1:1. does not correspond to

Therefore, each time the rotor angle changes, calculation processing must be performed within the CPU to constantly obtain the current rotor angle of the synchronous motor.

[Purpose of the invention]

An object of the present invention is to always determine the rotor angle of a synchronous motor by simply reading position data obtained from a position detector such as a resolver attached to the synchronous motor, even if the rotor of the synchronous motor is at an arbitrary angular position. It is an object of the present invention to provide a rotor angle detection device for a synchronous motor that meets the needs.

[Means and actions for solving problems] Therefore,
In the present invention, the Fj is connected to the rotor of the synchronous motor and at least one is capable of detecting an absolute angle within one rotation of the rotor.
A detection circuit that has several position detectors, a storage section that updates and stores the position data obtained from each of these position detectors, and a detection circuit that corresponds to the rotor angle of the synchronous motor from the position data stored in the storage section of this detection circuit. The present invention is characterized by comprising an arithmetic processing device that calculates position data to be used and sets the data in the storage section.

In short, if you calculate position data that matches the rotor angle before driving the synchronous motor and load this into a storage unit such as a position counter, the rotor angle of the synchronous motor and the value of the position counter will be 1:1 from then on. Since it corresponds to
The rotor angle can be determined simply by reading the value of the position counter.

〔Example〕

FIG. 1 shows an embodiment of the invention. In the figure, rotor shafts of an IX resolver 32 and a 10X resolver 33 as position detectors are sequentially connected to a rotor shaft 48 of a synchronous motor 31.

The primary excitation winding of each resolver 32.33 has an electric wire 50
An excitation current (Sin wave, Cos
waves) are supplied respectively.

Also, the secondary side output P of each resolver 32 and 33.

, Pz are led to the selector circuit 34 through electric wires 39 and 40, respectively. The selector circuit 34 is a central processing unit (hereinafter referred to as CPU) 3 as an arithmetic processing unit.
7 selects one of the outputs Pl+P2 and sends it to the waveform shaping circuit 35 through the electric wire 41.

The waveform shaping circuit 35 shapes the output sent from the selector circuit 34 into a rectangular wave, and sends the signal f to the phase synchronization circuit 52 via the voltage vA53. The phase synchronization circuit 52 is
A pulse corresponding to the phase difference between the signal r and the basic periodic signal r0 having the same period as the excitation signal given from the excitation circuit 49 is sent to the up/down counter 36 as a storage section via the voltage vA42.

The up/down counter 36 counts pulses from the phase synchronization circuit 52. This count value is
When the readout signal Rd from 7 is given to the up/down counter 36 through the electric wire 45, the
It is taken into PU37.

The CPU 37 selects IX out of the captured count values.
Assuming that the value from the resolver 32 is A+ and the value from the IOX resolver 33 is A2, position data φ corresponding to the rotor angle θ of the synchronous motor 310 is determined using the following calculation formula.

φ Bow S [+oo' )・1000+Az Here, 0s (
Q) means converting Q into an integer.

Furthermore, it is assumed that the number of pulses corresponding to one period of each resolver 32, 33 is 1000, and when the rotor angle of the synchronous motor 31 is 0, there is no phase difference between f and fo (phase synchronization is achieved). do.

Furthermore, the position data φ obtained by the CPU 37 is
is supplied to the launch circuit 38 via line 43, and
When the write signal Wr from 37 is given to the launch circuit 38 through the electric wire 46, the launch circuit 38
latched to. Position data φ latched in the launch circuit 38. is sent to the up/down counter 36 via the line 44, and is loaded into the up/down counter 36 between the Lo-levels of the write signal Wr from the CPU 37. Note that here, the waveform shaping circuit 35, the phase synchronization circuit 52, and the up/down counter 36 constitute the detection circuit 61 of this embodiment.

Now, in FIG. 1, the synchronous motor 31 is rotated to an arbitrary rotor angle θ. When stopped at , the rotor angle θ.

Position data φ corresponding to.

The relationship is shown in Figure 2. As can be seen from the figure, the amplifier down counter 36 is set to 100, which corresponds to the IOX resolver.
If you set it to the 00 base, the rotor angle of the synchronous electric motor 1a31 and the value of the up-down counter 36 will correspond to 1:1 from now on, so just reading the position data of the up-down counter 36 from the CPU 37 will be the same. The rotor angle of the M electric motor 31 can be determined.

In the above explanation, in FIG. 1, I
An example using the X resolver 32 and the IOX resolver 33 was shown. However, the 1X resolver is not limited to just a resolver as long as it measures an absolute amount within one rotation. Further, the IOX resolver may generally be an NX resolver as long as it requires higher accuracy, and is not limited to the resolver. For example, an inductosin or magnetic scale may be used.

Furthermore, the configuration of the detection circuit 61 is not limited to the configuration including the waveform shaping circuit 35, phase synchronization circuit 52, and up/down counter 36 described in the above embodiment; for example, the output r of the waveform shaping circuit 35 is latched. A configuration method may also be used in which the reference counter data is latched as a signal.

〔Effect of the invention〕

As described above, according to the present invention, position data that matches the rotor angle is calculated only once before driving the synchronous motor,
If the data is loaded into the storage section of the detection circuit, the position data corresponding to the rotor angle of the synchronous motor can be retrieved from the storage section thereafter, so that the position control of the synchronous motor can be easily performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing the relationship between the motor rotation angle and the resolver rotation angle. 31゛...Synchronous motor, 32.33...Resolver as a position detector, 35...Waveform shaping circuit, 36...
- Amplifier down counter as a storage unit, 37... CPU as an arithmetic processing unit, 52... phase synchronized circuit,
61...Detection circuit.

Claims (3)

[Claims] (1) It has a plurality of position detectors connected to the rotor of the synchronous motor, at least one of which can detect an absolute angle within one rotation of the rotor, and a storage unit that updates and stores the position data obtained from each of these position detectors. A detection circuit, and an arithmetic processing device that calculates position data corresponding to the rotor angle of the synchronous motor from the position data stored in the storage section of the detection circuit and sets the data in the storage section. Features: Rotor angle detection device for synchronous motors. (2) In claim 1, the rotor angle of the synchronous motor is characterized in that the position detector is comprised of a single-pole resolver and a multi-pole resolver connected to the rotor of the synchronous motor. Detection device. (3) In claim 2, the detection circuit detects, for the secondary output of each of the resolvers, a phase difference between an excitation signal supplied to the primary side and a rectangular wave signal having the same period. 1. A rotor angle detection device for a synchronous motor, comprising: a phase synchronized circuit; and an up/down counter that counts pulses proportional to a phase difference obtained from the phase synchronized circuit.