JPH0780648B2 - Control device for elevator inverter - Google Patents

Description

The present invention relates to an elevator inverter control device having a current control system, and more particularly to a current control device.

B. Outline of the Invention The present invention has a current control system in the minor loop of the speed control system, and controls the inverter output current by the torque current command from the speed control system. By adding the boost current to the torque current command, the elevator start shock and speed instability during deceleration stop are eliminated.

C. Prior Art An elevator drive device using an inverter having a current control system is configured, for example, as shown in FIG. The inverter main body 2 to which the DC power is supplied from the rectifier 1 is configured in a voltage-type inverter main circuit and controls the speed of the induction motor 3 serving as an elevator drive source. The control device matches the speed command N according to the speed pattern with the speed detection pickup 4 of the electric motor 3 and the detected speed N _s from the speed detection circuit 5 to perform speed control calculation by the speed control amplifier 6, and outputs this output. Torque current command I _T Current command I ₁ (= √I ₀ ² + I _T ² ) that makes the excitation current setting value T ₀ orthogonal by the vector control calculation unit 7 and frequency command SINU (SIN (ωot +
φ)), SINV (= SIN (ωot + φ-2π / 3)), and the frequency command is converted into an analog signal by the D / A converter 8 and the amplitude control is performed according to the current command I ₁ I _U and I _W are obtained, and the voltage control signals V _U and V _W for two phases are supplied to the current control amplifiers 9 ₁ and 9 ₂ that form a minor loop by matching this command with the U and W phase output current detection signals of the inverter. Then, the V-phase voltage control signal is obtained through addition of both signals and the inverting amplifier 10, each voltage control signal V _U , V _V , V _W is modulated into a PWM waveform by the pulse width control circuit 11, and further the gate amplifier is obtained. Gate control of the inverter oil circuit 2 is performed by power amplification by 12.

D. Problem to be Solved by the Invention A conventional elevator drive device has a configuration in which a current control minor loop is provided in a speed control loop, and the elevator is repeatedly operated in a speed pattern of start-acceleration-constant speed-deceleration-stop. Is not compensated for the torque generated by the friction of the mechanical system at the time of low-speed operation and at the time of starting, and as shown in FIG. 6, when the actual speed rises shown by the broken line with respect to the speed command N shown by the solid line. There was a risk of causing an uncomfortable feeling and anxiety to the occupant due to a start shock accompanied by a sudden change in speed and unstable speed such as vibration immediately before the completion of elevator deceleration.

It is an object of the present invention to provide a control device for an elevator inverter that eliminates start shock and speed instability during deceleration stop.

E. Means and Actions for Solving the Problem In order to achieve the above object, the present invention has a current control system in the minor loop of the speed control system, and the current from the torque current command from the speed control system and the output current of the inverter. In a control device for an elevator inverter that performs current control by a control system, the elevator machine is provided with an addition unit that adds a torque boost current corresponding to a torque component due to friction of a mechanical system of the elevator to the torque current command. Compensate for insufficient torque due to system friction.

Further, according to the present invention, gain adjusting means for reducing the torque boost current corresponding to the torque component due to friction of the mechanical system of the elevator as the elevator speed command becomes faster, and the torque boost current adjusted by the gain adjusting means is used as the torque current command. And an adding means for adding to the torque compensation, and the torque compensation is increased at the time of starting and decelerating the elevator to perform torque shortage compensation while eliminating excessive compensation at medium and high speeds.

F. Embodiment FIG. 1 is a circuit diagram of essential parts showing an embodiment of the present invention. The vector control calculation unit 7 is constructed in the same manner as that of FIG.
When the vector current command I _T and the exciting current command I ₀ are orthogonal to each other, the size of the composite vector is calculated by the calculation unit 7 ₁ and the current command is calculated.
Get i ₁ Also, determine the phase angle φ by arctangent calculation of the arithmetic unit 7 ₂ both instruction, obtains a phase variation Δφ by differentiating further calculation unit 7 _3. The arithmetic unit 7 ₄ both command I _0, I _T and the secondary time constant of the motor _{τ 2 (= L 2 / R} 2) from the slip frequency omega _s
Is calculated, and the detected speed ω _r from the speed detector ₅ is added to this by the addition unit ₇₅ to calculate the operating frequency ω ₀ . Then, sequentially outputs the desired sine wave sample sequence data by an access period and the address adjustment ROM data having the sample values of the sine wave from the sine wave generating portion 7 ₆ In the phase variation Δφ as operating frequency omega _0. This output is sampled data string _{SINU = SIN (ω 0 t +} φ) SINW = SIN (ω 0 t + φ-2π / 3).

Next, the D / A converter 8 outputs the SINU,
Current command I _U converts SINV into analog signals, to obtain the I _W, the current command and current command I ₁ from the arithmetic unit ₇₁ and coefficient multiplication
Set the amplitudes of I _U and I _W as expected.

Here, the current command I ₁ is added to the torque boost current I _B by the adder 21, and the addition result I ₁ + I _B is added to the D / A converter 8
The conversion factor of This torque boost current I _B is given as a starting and deceleration stop only when the bias current value of or elevator over the entire high speed region from the low speed range.

Therefore, when starting and deceleration stop of the elevator, the torque current command I _T and the exciting current command current command I ₁ to the torque boost current I motor 3 in _B content is added current determined from I ₀ is driven, at the start compensating a torque shortfall caused by friction of the mechanical system as a torque boost current I _B component, also suppresses the torque boost current I _B vibrations when entering the low-speed operation for the deceleration stop.

The torque characteristics of the elevator mechanical system, as shown in FIG. 2, is roughly divided into a static friction torque region and the velocity V ₀ which from the speed zero to the speed V ₀ to the windage torque region of fastest V _MAX, Torque compensation by the torque boost current I _B is mainly performed for torque shortage and excessive torque due to static friction torque, and compensation for wind loss in the middle and high speed regions can be sufficiently compensated by the speed control system. Further, when the elevator is descending, the polarity of the torque current command I _T is opposite to that when the elevator is descending, but at this time as well, the polarity of the torque boost current I _B is not switched, and the excess of the torque command I _T during the descending ( Static friction torque).

FIG. 3 is a circuit diagram of essential parts showing another embodiment of the present invention.
1 is different from FIG. 1 in that the torque boost current I _B is adjusted by the gain control amplifier 22 according to the speed command N, and the output I _B ′ is given as the added torque boost current of the adder 21. . Adjustment of the torque boost current I _B due to the gain control amplifier 22, as shown in FIG. 4, the speed command N is to be zero at the maximum speed of forward or reverse,
Maximum torque boost current I when speed command N is zero (stop)
_BMAX is set, and the characteristic is set to have a constant ratio as shown by a solid line or to change exponentially as shown by a broken line.

In this embodiment, medium speed of the elevator, the higher the torque boost current command I _B becomes the high-speed operation low. As a result, the torque boost current I _B during the medium and high speed operation of the elevator
The torque boost compensation due to the torque boost compensation is reduced, preventing the torque boost compensation in the operating range from being overexcited and causing vibration or noise.In addition, the inverter output voltage rises to near the power supply voltage and the control becomes unstable. It is possible to obtain sufficient torque compensation at the time of starting and decelerating and stopping while preventing the occurrence of vibration due to the above.

Although the embodiment shows the case of the vector control, the present invention can be applied to a slip frequency control device or the like to obtain the same operational effect.

G. Effect of the Invention As described above, according to the present invention, the torque boost current corresponding to the torque component due to the friction of the mechanical system of the elevator is added to the torque current command. It is possible to perform torque compensation while preventing the vibration. Further, since the torque boost current is made smaller as the speed becomes higher in response to the speed command of the elevator, there is an effect that start shock and vibration can be prevented while eliminating excessive torque compensation in the high speed and middle speed regions.

[Brief description of drawings]

FIG. 1 is a circuit diagram of essential parts showing an embodiment of the present invention, FIG. 2 is a speed-mechanical torque characteristic diagram of an elevator, and FIG. 3 is a circuit diagram of essential parts showing another embodiment of the present invention. 4 is a torque boost current characteristic diagram in FIG. 3, FIG. 5 is a configuration diagram of an elevator drive device, and FIG. 6 is a speed waveform diagram of the elevator. 5 ... Speed detection circuit, 7 ... Vector control calculation unit, 8 ...
… D / A converter, 21 …… Adder, 22 …… Gain adjustment circuit.

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Claims (2)

[Claims] 1. An elevator inverter controller having a current control system in a minor loop of a speed control system and performing current control by the current control system from a torque current command from the speed control system and an output current of the inverter. A control device for an elevator inverter, comprising: an addition unit that adds a torque boost current corresponding to a torque amount due to friction of the mechanical system to the torque current command. 2. A control device for an elevator inverter, comprising a current control system in a minor loop of a speed control system and performing current control by the current control system from a torque current command from the speed control system and an output current of the inverter. And a gain adjusting means for reducing the torque boost current corresponding to the torque due to friction of the mechanical system as the elevator speed command becomes faster, and an adding means for adding the torque boost current adjusted by the gain adjusting means to the torque current command. A control device for an elevator inverter, comprising: