SU1336189A1 - A.c.electric drive - Google Patents

Abstract

The invention relates to electrical engineering and can be used in machine tools, modeling stands. The aim of the invention is to simplify and improve the use of heating. This goal is achieved by executing the switch (K) 4 in the AC controlled electric drive and introducing frequency dividers 9, 10, the setpoint generator 11 of the correction signal, the phase shifting unit 12, the K control unit 13 and the shifting unit 14. As a result, K 4 of a contactless tachogenerator 3 is controlled by an inductive rotor position sensor 2 of the engine 1 without using an additional photoelectric position sensor having a limited operating temperature range. 4 il. with with O5 00 with

Description

The invention relates to electrical engineering, namely, frequency-controlled electric drives based on an AC machine and a contactless tachogenerator, and can be used, for example, in machine tools, modeling stands, etc.

The aim of the invention is to simplify the design and improve the use of the engine for heating.

FIG. 2 - schematic diagrams of possible variants of the second frequency divider, shift unit and switch control unit; in fig. 3 shows diagrams explaining the operation of the second frequency divider, the shift unit and the switch control unit; in fig. 4 - diagrams for the switch operation.

Numbers of pairs of motor poles, syn15

the shifting unit 12 is connected to the output of the inductive position sensor 2, and the second to the output of the correction signal setting device 11.

Frequency dividers 9 and 10 contain a register 15 (Fig. 2) covered by feedback through the AND-NOT element 16. The output of register 15 through another element IS-NOT 17 is the output of the frequency divider. The shift block 14 contains a register 18 operating in

FIG. Figure 1 shows the functional shift mode. The control unit 13 has an AC drive circuit; on register 19 operating in recording mode

The C-input of which is control, and the D-inputs are informational inputs of control unit 13.

As a position sensor 2, an electric machine such as a selsyn or a rotating transformer operating in a phase shifter mode can be used. Tachogenerator 3 is a synchronous generator with a trapezoidal chronic tachogenerator and an inductive 20 form of output voltage. The generator 5 of the position sensor is equal to the pulses, respectively, may contain three, two and one sequences, and the number of phases of the blue connected C-circuit and the elements of NAND. the chronic tachogenerator is equal to three. The frequency matching block can be - (Fig. 2-4). It is filled in the form of a series-connected AC drive containing a common frequency divider and an AC motor 1 (Fig. 1), 5 harmonic signals. As a setpoint inductive sensor 2, the position of the rotor of the correction signal 11 can be an engine, contactless synchronous tachometer any adjustable source to generator 3 mechanically connected with rotor voltage, in the simplest case it is a potential of engine 1 alternating current, a commiometer connected to the busbars of the power supply 4, the information inputs of which, the electric drive control systems. Phase connected to the outputs of contactless sync „,,,,,„ th “n ,, th ...„ „.„ D, ™. „

a chronic tachogenerator 3, a series-connected pulse generator 5 and a frequency matching unit b, connected by an output to the input of an inductive rotor position sensor 2, are connected in series to a driver 7 of control signals with three inputs and an amplifier 8 phase currents, the outputs of which are connected to the phase windings of the variable-frequency motor 1 current, while the first input of the generator 7 of the control signals is connected to the output of the inductive 40 ryg using an asynchronous or synchronous-sensor 2 position, and the second input is connected to The device is fed from the amplifier 8 with the phase output of the switch 4, made of packed currents. On the engine shaft is set equal. In the electric variable position sensor rotor 2. A current generator 5 is introduced by two dividers of 9 and 10 frequencies, the pulses are produced by rectangular correction signals 11, phase shift pulses U with frequency / (Fig. 3 a); which block 12 with two inputs, block 13 is fed simultaneously to the inputs of the control dividers of the switch with the control and 9 and 10 frequencies and the block 6 of the matching information inputs and the block 14 of the shift, the output of which is formed

connected to the output information required two-phase sine-wave system-input unit 13 control switch 4, voltage to ensure the operation of the control input unit 13 is connected to the output of the sensor 2 rotor position mode - J, and., - 10 l., phase shifter Frequency of these voltages

35

shifting unit 12 may be made of series-connected summing comparator and pulse shaper. The inputs of the summing comparator are the inputs of the phase-shifting unit 12, the output of which is the output of the pulse shaper.

The AC drive with contactless tachogenerator works as follows.

Winding engine 1 (which is

. ".

Rd-Risg

(where RD and RISG are the numbers of pairs

the house of the phase-shifting unit 12, the output of the control unit 13 is connected to the control input of the switch 4, the inputs of the frequency dividers 9 and 10 are connected to the output of the pulse generator 5. The output of the first frequency divider 9 is connected to the third input 55 of the chronic tachogenerator). control signal generator 7, the output voltage of the sensor 2 polo (FIG. 3 g) is determined

the poles, respectively, of the motor and the synchronous output of the second divider 10 frequency - to the input of the block 14 shift. The first entry of the rotor fazozheni expression

As a position sensor 2, an electric machine such as a selsyn or a rotating transformer operating in a phase shifter mode can be used. Tachogenerator 3 is a synchronous generator with a trapezoidal 0 form of output voltage. The pulse generator 5 may contain serially connected A / C-circuits and NAND elements. The frequency matching unit can be implemented in the form of a serially connected frequency divider and shaper 5 harmonic signals. Any adjustable voltage source can be used as the correction signal selector 11, in the simplest case it is a potentiometer connected to the power busbars of the electric drive control system. Phase n „,,,,,„ th “n ,, y ...„ „.„ D, ™. „

0 asynchronous or synchronous motor is used) are fed from an amplifier 8 phase currents. The rotor position sensor 2 is mounted on the engine shaft. The 5 pulse generator produces rectangular im5

shifting unit 12 may be made of series-connected summing comparator and pulse shaper. The inputs of the summing comparator are the inputs of the phase-shifting unit 12, the output of which is the output of the pulse shaper.

The AC drive with contactless tachogenerator works as follows.

Winding engine 1 (which is

. ".

Rd-Risg

(where RD and RISG are the numbers of pairs

chronic tachogenerator). The output voltage of the sensor 2 polochrone tachogenerator). The output voltage of the sensor is 2 half-poles, respectively, of the motor and the rotor syngen expression

(/ 2 fym2Sin (- - / -РДпв), l- n / - ксг

where in is the geometric angle between the axis of the primary winding of the rotor position sensor 2, supplied by the voltage L / i fymiX

f 9m

Xsin - /: - I- / (fig. 3 e), and the axis of its rotor.

Hl g isg

Wherein

in 2p / vr; + in,

where fep is the rotor speed of the engine;

0, is the angle value when f «/ 0.

The division factors of the dividers 9 and 10 frequencies are equal respectively to Rdp-Risg and Rdp.rd, where Rdp is the number of pole pairs of sensor 2 of the rotor position.

Pulses from the output (/ 7dch) divider 10

frequencies with frequency „and. (Fig. 3 b) RFP Rd

step to the input of the shift block 14, the output of which forms a multi-phase system of rectangular pulses (Ubs) of the same frequency (Fig. 3 d, c, d), and the pulses of adjacent phases are shifted relative to each other by an angle φ determined by the number of phases of the tachogenerator 3 and the execution circuit of the switch 4. These pulses arrive at the information inputs of the control unit 13. The voltage Uz (fig. 3 g) from the output of the position sensor 2 is fed to the first input of the phase-shifting unit 12, which, in order to match the position of the stator windings of the tachogenerator 3 with the axes of the input windings of the rotor position sensor 2, additionally displaces the phase Uz by an angle a, voltage function Ua, coming from the output of the setter 11 of the correction signal to the second input of the phase-shifting unit 12. At time points

Risg + a)

2n /

i.e., at the instants of changing the sign of the algebraic sum of the input voltages of the phase-shifting unit 12 from negative to positive, a pulse ipsb is formed at its output (Fig. 3h), which arrives at the control input of the control unit 13. In this case, the latter records information from the output of the shift block 14 (Fig. 3, k, d). After the end of this pulse, the information at the outputs of control unit 13, corresponding to the time instant ta, is stored until the next pulse arrives. Thus, at each of the outputs of the control unit 13, a logical signal is generated

(r.o + f, -)

OR Taking into account the above expression for Uyi sign {sm p г cr () + F ,,

pi

to

where i is the sequence number of the output of the control unit 13 (Fig. 4 g, d, e). That is, the phase of the signal Uyi is related to the angle of rotation of the rotor by the coefficient P "er, which takes into account the number

From the pairs of poles of the synchronous tachogenerator 3. From the outputs of the control unit 13, the signals Uyi are fed to the control inputs of the switch 4, the open or closed state of its channels is determined.

The horizontal sections of the trapezoidal EMF / 1, / 2 and / 3 (vertex trapezium) of the corresponding phase windings of the tachogenerator 3 (Fig. 4 a, b, c), connected to the information inputs of the switch 4, are transmitted to its output corresponding signals Uy /, which are functions of the rotor position.

Thus, the output voltage of the switch 4, which is the output voltage of the tachogenerator (iAr), consists of horizontal sections of trapezoidal

0 The EMF of the phase windings of the tachogenerator (Fig. 4 g) and its magnitude is directly proportional to the frequency of rotation of the motor 1.

Voltage {Utg, which is a speed feedback signal, arrives

, to the second input of the driver 7 control signals. The first input receives the voltage Uz from the output of the rotor position sensor 2, and the third receives the voltage from the output of the 9 frequency divider with the frequency converted in this block

0Rdp-Risg

in a harmonic signal (7z the same frequency.

DVRdRisgRdpv

at times, i.e.

2n /

at the moments of changing the sign of the voltage U-2 from negative to positive, the voltage signal is recorded in the driver 7 of the control signal (Uz, corresponding to the time point to, and it is stored until the next pulse arrives. As a result, 0

(У4 51П - J- / 0 | 51пРдпв; / - дп.

45

.5 - J- / 01 S08Rd in, {- an

With the help of which the coordinate transformations of the signals from the coordinate system associated with the rotor, including the torque reference signal, which is a speed error function, to the fixed coordinate system associated with the stator are made. The output voltages of a control signal conditioner are control signals for a different current amplifier.

Thus, the introduction of two frequency dividers, a shift unit, a switch control unit, a phase-shifting unit and a correction signal setpoint generator with appropriate connections into the AC drive with a contactless tachogenerator allows controlling the contactless tachogenerator switch with an inductive position sensor without using an additional photoelectric position sensor having a limited operating temperature range, and therefore simplify the design and improve the use of of the engine for heating compared with a known solution.

Claims (1)

Invention Formula 10 control switch with control and information inputs and a shift unit connected by an output to the information input of the control block and a switch, the control input of which is connected to the output of the phase-shifting block, and the output An AC electric drive containing a motor, an inductive rotor position sensor, and a contactless synchronous tachogenerator, mechanically connected to a 15 switch control unit is connected with motor rotor, commutator, information to the control input of the commutator, inputs The function inputs of which are connected to frequency dividers are connected to the output. the contactless synchronous tachoge pulse generator, the output of the first deliner, serially connected frequency generators are connected to the third input of the pulse rampter and the matching unit hour, - 20 control signal generator, the output connected to the input of the second frequency divider to the input - the entrance rotor position sensor, after-shift unit, the first input of the phase-shifting Vetually connected shaper control unit connected to the output of the inductive signals with three inputs and a force sensor, and the second with an output phase current currents, the outputs of which are the sub-setter of the correction signal. R ten -four sg5 five sh- iJllJ They are connected to the phase windings of the engine, the first input of the driver of the control signals is connected to the output of the inductive position sensor, and the second input to the output of the switch, characterized in that In order to simplify and improve the use of the engine for heating, the switch is made controllable, and two frequency dividers are introduced, a correction signal adjuster, a phase shifting unit with two inputs, a unit control switch with control and information inputs and a shift unit connected by an output to the information input of the control block and a switch whose control input is connected to the output of the phase-shifting block, the output switch control unit connected prg I f5 T u L. as.l -P PC512