CS225690B1 - Connection for the speed regulation or the synchronous motor position with the semiconductor frequency transducer - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a circuit for controlling the speed of a drive position with a synchronous three-phase motor powered by a direct or indirect semiconductor frequency converter.

The prior art connections for controlling the speed or position of a synchronous motor use sensors to be mechanically coupled to the motor shaft to sense the position and speed. Sensors mounted on the motor increase the total moment of inertia and cause installation and maintenance problems. The actual position and speed of the motor are necessary for the control circuits to be optimally controlled.

The above drawbacks overcome the circuitry for controlling the speed or position of a synchronous motor according to the invention, the principle being that the three-phase synchronous motor is connected to the output of the fraction converter, with a three-phase current sensor connected to the synchronous motor. The output from the three-phase current sensor is connected both to the feedback input of the three-phase current regulator circuit and to the three-phase input of the three-phase direct transformation circuit to the two-phase system. The output from the direct three-phase to two-phase system is connected to the input of the speed and position evaluation circuit, and the speed output of the speed and position evaluation circuit is coupled to the feedback speed input of the speed and position control circuit.

The position output of the speed and position evaluation circuit is connected to the feedback position input of the speed and position control circuit, and its control input is connected to

225 690 only position input circuit. The output of the speed and position control circuit is coupled to the control input of the two-phase reverse transformer circuit to the three-phase system, and the output of the reverse transform circuit is coupled to the control input of the three-phase current regulator circuit. The output of the three-phase current regulator circuit is connected to the frequency inverter input. The position output of the speed and position evaluation circuit is further connected to the position input of the system's direct and reverse transformation circuit. The advantage of said circuitry is to obtain the actual ratios and rotor position signals of the synchronous motor indirectly from the instantaneous three-phase current quantities using the three-phase direct and reverse transformers to the two-phase system and the speed and position evaluation circuit. This eliminates the need for direct speed and position sensors. Another advantage of this circuit is the optimal control of the synchronous motor in terms of energy indicators such as cos = · 1 (or capacitive), optimum efficiency and optimal dynamic properties of the drive.

The drawing shows the connection of the control circuits for controlling the speed and position of the three-phase synchronous motor supplied from the frequency converter.

The three-phase synchronous motor χ is supplied from a transistor or thyristor frequency converter 2 and in the supply to the motor 1 there is a three-phase current sensor 8 consisting of three separate current sensors 8 ^X. 8. 8 in each phase of the motor. The output of the three-phase current sensor 8 is connected both to the feedback input of the current regulator circuit X and to the three-phase input of the direct transform circuit 4 of the three-phase to two-phase system. The output of the three-phase direct-to-two-phase direct transform circuit 6 is connected to the input of the speed and position evaluation circuit 6, which has two outputs. Its velocity output is connected to the speed feedback of the speed and position 7 circuit, while its positional output is coupled to the feedback position input of the velocity and position 7 circuit,

The setpoint of position is entered from the circuit at position χ. The input signal from the speed and position 2 control circuit comes to the control input of the 2-phase to 3-phase reverse transformer circuit X. The re-transformed three-phase current reference signals at the output of the X-phase reverse transformer circuit to the three-phase system are applied to the control input of the X-phase controller having three separate controllers 31. 32. 33. The output signals from the X-phase controller are controlled by The position output from the speed and position evaluation circuit 6 further enters the direct 4 circuits, and the backward X transformations of the three-phase to two-phase system consist of permanent memories 41. 42. 43; XX, 52. XX, in which the digital position of the rotor T? ' χ transforms cos 1 ^, cob (l / l - 27Γ / 3), cos (ift + 2773), sin ^, sin (^ - 2T / 3), sin (^> + 2 ^ 73) to trigonometric functions . Then, these signal functional values come to the digital-to-analog multiplication converters 44. 45. 46; 54. 55. 56, and also to 47. £ 8, 49; 57, 58, XX, in which the trigonometric function is multiplied by the phase current in the case of a direct system transformation, or by the current vector setpoint, i.e. the output signal from the velocity and position control circuit X » ^{in the} case of a system reverse transform according to equations!

225 690

For direct transformation of three-phase to two-phase system i _d k k _d [i _a cos ^ + i _b cos (^ - 27r / 3) + i _c cos (^ + 2T / 3) J i _q = -k _g £ i _a sin $ + i _b sin (^ ^ - 27773) + i _c sin (^ + 2T, to reverse the two-phase to three-phase system i _a = 2/3 | COS ify- 2/3 l / k (i _q sin ^ i _b = 2/3 l / k ^ _d cos (· ^ - 27773j - 2/3 l / kjšin (^ - 2 773) i ₀ - 2/3 l / k ^ coaCiA + 27773) (- 2/3 l / kjin (^ + 2 ~ / 3)?

tg (f

Taking iJi d q where f «0 or constant, ^ 3 load angle k, k b constant, ú q

At the input of the velocity and position evaluation circuit 6, the output signal comes from a three-phase to two-phase direct transformation circuit 4. The signal enters the regulator of the longitudinal component of the current 6l. The output of the longitudinal component 61 is coupled to the input of the absolute value member 62 and to the input of the camera 63. The output signal of the absolute value member 62 controls the voltage-controlled oscillator 64. The direction of counting of the bidirectional counter 65 is controlled by the output signal from the comparator 63. The pulse frequency at the output of the voltage-controlled oscillator is proportional to the speed of the synchronous motor 1 and the output voltage of the comparator 63 indicates the direction of rotation. The output of the bidirectional counter 65 then indicates, in digital form, the rotor position of the synchronous motor 1. The bidirectional counter 65 is reset by a signal from the rotor zero position, for example, when the induced phase voltage passes through zero. The position signal enters the speed and position control circuit 7 and arrives at the digital-to-analogue position converter 75 and then at the positioner 71 input together with the position reference signal from the positioning input circuit Fo processing the output signal from the positioner 71 in the optimization member 72 a signal to the speed controller 73 wherein the actual value of the speed signal comes to the speed controller 73 from the digital-to-analog speed converter 76. After limiting the output signal from the speed controller 73 in the current reference limiter 74, as setpoint, the current vector value.

In a specific implementation of the wiring, some or all control and regulation circuits can be solved as digital by means of a microprocessor. If the position controller 71 is disabled and the speed setpoint 73 is connected to the input of the speed controller 73, the wiring serves as a speed-controlled control drive.

This connection can also be used for all electric machines of synchronous type rotary and linear motion, excited, with commemorative magnets and also for reaction and stepper motors. In addition to the three-phase motor, a different number of phases m may be used if the direct and reverse phase transformers m of the two-phase system are used.

Claims (2)

1. Wiring for speed control or position control of a synchronous motor with a solid-state frequency converter with a three-phase current regulator, upstream or downstream speed controllers, and with three-phase direct and reverse transformers for two-phase 225 690, characterized in that a three-phase synchronous motor (1) is connected to the output of a three-phase frequency converter (2), and a three-phase current sensor (8) comprising three separate single-phase current sensors (8) is connected to the synchronous motor (1). 81, 82, 83) connected in each phase of the synchronous motor (1) and that the output of the three-phase current sensor (8) is connected both to the three-phase feedback output of the three-phase current controller circuit (3) and to the three-phase input 4> three-phase to two-phase system, and that the output of the three-phase to two-phase direct transformation circuit (4) is coupled to the input of the speed and position evaluation circuit (6), the amplitude and sign rate output of the speed and position evaluation circuit (6) connected in series to the amplitude and sign feedback speed input of the speed and position control circuit (7), and the position output of the speed and position evaluation circuit (6) is connected to the feedback position input of the speed and position control circuit (7), wherein the position control input of the speed and position control circuit (7) is connected to the position input circuit (9); the output of the speed and position control circuit (7) is coupled to the control input of the two-phase reverse transformer (5) to the three-phase system, the three-phase output of the two-phase reverse transformer circuit (5) to the three-phase system ) and the three-phase output of the three-phase current regulator circuit (3) is coupled to the three-phase input of the frequency converter (2) and that the position output of the speed and position evaluation circuit (6) is further connected to the three-phase to two-phase system and to the position input of the reverse transformer circuit (5) two-phase to tro jfázový systém. 2. The synchronous motor speed and position control circuit as set forth in claim 1, wherein the output of the three-phase, two-phase, direct transformation circuit (4) connected to the input of the speed and position evaluation circuit (6) is connected to the longitudinal current regulator input. (6l), the output of the longitudinal component (6l) is connected both to the input of the absolute value member (62) and to the input of the comparator (63), the output of the absolute value member (62) being connected to the voltage controlled oscillator input and that the output of the voltage controlled oscillator (64) is connected to the counter input of the bidirectional counter (65) and simultaneously to the amplitude velocity output of the speed and position evaluation circuit (6), the comparator output (63) being connected to the bidirectional counter input (65) while being coupled to the sign rate output of the speed and position evaluation circuit (6), the bidirectional counter output is a position output of the speed and position evaluation circuit (6), the bidirectional counter reset input (65) being coupled to the rotor zero position sensor output.