Sensorless control device for synchronous electric motor

Claim 2

A synchronous motor sensorless controller which includes a current sensor for detecting an electric current of a synchronous motor, a position-and-speed estimation device for computing an estimated speed of the synchronous motor and an estimated position of a magnetic pole through use of the current output from the current sensor, and a speed controller for controlling speed of the synchronous motor through use of a speed instruction and the estimated speed; and which drives the synchronous motor without use of a rotational position sensor, the controller comprising: reference position signal output means for outputting a reference position signal serving as a standard for positioning counting operation; a relative position counter which acquires an estimated position of a magnetic pole from the position-and-speed estimation device as a reference position simultaneously with resetting a summated value to zero when the reference position signal is input and which starts summation operation; and a speed instruction generator having a position controller which performs position control operation on the basis of a deviation between an instruction value pertaining to the amount of movement from the reference position and a summated value output as a relative position from the relative position counter, the speed instruction generator outputting a speed instruction, wherein the speed instruction generator enables setting of a deceleration start position and a stop operation start position, starts deceleration operation when a summated value output from the relative position counter as a relative position has reached the deceleration start position, and starts stop operation when the summated value has reached the stop operation start position.

Claim 3

The synchronous motor sensorless controller according to claim 1 , wherein the speed instruction generator can set at least two pairs, each pair formed from a deceleration start position and a stop operation start position, enables selection of one to be used during operation from the deceleration start position and the stop operation start position, starts deceleration when a summated value output from the relative position counter as a relative position has reached a selected deceleration start position, and starts stop operation when the summated value has reached a selected stop operation start position.

Claim 4

A synchronous motor sensorless controller which includes a current sensor for detecting an electric current of a synchronous motor, a position-and-speed estimation device for computing an estimated speed of the synchronous motor and an estimated position of a magnetic pole through use of the current output from the current sensor, and a speed controller for controlling speed of the synchronous motor through use of a speed instruction and the estimated speed; and which drives the synchronous motor without use of a rotational position sensor, the controller comprising: reference position signal output means for outputting a reference position signal serving as a standard for positioning counting operation; a relative position counter which acquires an estimated position of a magnetic pole from the position-and-speed estimation device simultaneously with resetting a summated value to zero when the reference position signal is input and which starts summation operation; stop operation start position signal output means for outputting a stop operation start position signal; and a speed instruction generator having a position controller which performs position control operation on the basis of a deviation between an instruction value pertaining to the amount of movement from the reference position and a summated value output as a relative position from the relative position counter, the generator outputting a speed instruction, wherein the speed instruction generator enables setting of a changed speed instruction and a deceleration start position, changes a speed instruction to the changed speed instruction when a reference position signal is input, starts deceleration operation when a summated value outputted from the relative position counter as a relative position has reached the deceleration start position, and starts stop operation when a stop operation start position signal is outputted from the stop operation start position signal output means.

Claim 5

A synchronous motor sensorless controller which includes a current sensor for detecting an electric current of a synchronous motor, a position-and-speed estimation device for computing an estimated speed of the synchronous motor and an estimated position of a magnetic pole through use of the current output from the current sensor, and a speed controller for controlling speed of the synchronous motor through use of a speed instruction and the estimated speed; and which drives the synchronous motor without use of a rotational position sensor, the controller comprising: reference position signal output means for outputting a reference position signal serving as a standard for positioning counting operation; a relative position counter which acquires an estimated position of a magnetic pole from the position-and-speed estimation device simultaneously with resetting a summated value to zero when the reference position signal is input and which starts summation operation; stop operation start position signal output means for outputting a stop operation start position signal; and a speed instruction generator having a position controller which performs position control operation on the basis of a deviation between an instruction value pertaining to the amount of movement from the reference position and a summated value output as a relative position from the relative position counter, the generator outputting a speed instruction, wherein the speed instruction generator enables setting of a changed speed instruction and a deceleration start position, changes a speed instruction to the changed speed instruction when a reference position signal is input, starts deceleration operation when a summated value outputted from the relative position counter as a relative position has reached the deceleration start position, and starts stop operation when a stop operation start position signal is outputted from the stop operation start position signal output means.

Claim 6

The synchronous motor sensorless controller according to claim 3 , wherein the speed instruction generator enables setting of a first changed speed instruction, setting of a second changed speed instruction, setting of a first operation change relative position, setting of a second operation change relative position, and setting a deceleration start position; changes a speed instruction to the first changed speed instruction when the reference position signal is input; changes the speed instruction to the second changed speed instruction when the summated value output from the relative position counter as a relative position has reached the first operation change relative position; changes the speed instruction to the first changed speed instruction when the summated value has reached the second operation change relative position; starts deceleration when a summated value output from the relative position counter as a relative position has reached the deceleration start position; and starts stop operation when a stop operation start position signal is output from the stop operation start position signal output means.