JP2005278224A - Elevator controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elevator controller which is reduced in size while having a high frequency suppression filter requiring no damping resistor. <P>SOLUTION: The elevator controller comprises a high frequency suppression filter 2 consisting only of a reactor and a capacitor connected with a commercial power supply 1, a converter 4 for converting an input AC into DC, AC current detectors 3a and 3b for detecting a current flowing on the AC side of the converter, PI controllers 82a and 82b for obtaining a voltage command by PI control operation on the basis of current detection signals from the AC current detectors, filters 83a and 83b passing the components of a resonance frequency and higher frequencies from the current detection signals, and a PWM controller 86 for performing PWM control of the converter on the basis of a final voltage command obtained by performing addition for the voltage command output from the PI controller such that the resonance frequency components output from the resonance frequency passing filter are offset. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an elevator control device.

  Conventionally, an elevator control device in which a converter / inverter device is connected to a commercial power source via a harmonic suppression filter has the configuration shown in FIG. 8, and a reactor L 1, a reactor L 2, a capacitor C, and a damping resistor R with respect to the commercial power source 101. The converter 104 is connected through the harmonic suppression filter 102 configured as described above. Although the harmonic suppression filter 102 is omitted in the drawing, the reactor L1 and the reactor L2 are connected in series to each of the three phases, and the damping resistor R and the capacitor C are connected between the three phases. It is.

  In this conventional elevator control device, current detectors 103 a and 103 b are provided between the harmonic suppression filter 102 and the converter 104 to detect the power source side currents Iu and Iw. The current Iv is obtained from the detected Iu and Iw in consideration of the three-phase equilibrium, and the three-phase to two-phase conversion is performed to calculate the d-axis and q-axis currents Id and Iq. The d-axis and q-axis currents Id and Iq and the current commands Idc and Iqc are PI-controlled by a current controller to obtain d-axis and q-axis voltage commands Vdc and Vqc as voltage commands. Further, the d-axis and q-axis voltage commands Vdc and Vqc are subjected to two-phase to three-phase conversion to obtain three-phase voltage commands Vuc, Vvc and Vwc. From the calculated three-phase voltage commands Vuc, Vvc, and Vwc, a PWM control circuit creates a gate signal for the switching element of the converter, performs switching control, and controls power.

In such a conventional elevator control device, when switching control is performed, a harmonic current caused by switching flows to the power supply side, and thus a harmonic suppression filter 102 is connected to suppress this harmonic. This filter has a unique vibration frequency. For example, the inherent vibration frequency fc of the harmonic suppression filter 5 is expressed as follows.

  For example, when L1 = 0.15 mH, L2 = 0.35 mH, and C = 45 uF, the natural vibration frequency fc is 2.12 kHz. When the frequency component of the harmonic current matches the natural vibration frequency of the harmonic filter, resonance occurs and distortion occurs in the power supply current. Therefore, a damping resistor is installed to suppress this resonance.

  However, the resistor generates heat by inserting this damping resistor. In addition, since the amount of flowing current increases in a system with a large capacity, it is necessary to take sufficient derating in accordance with it, so it is necessary to select a resistor with a large shape. It gets bigger. In the case of an elevator with a limited machine room size when the apparatus is enlarged, there is a problem that the apparatus itself cannot be installed or the inspection space is reduced even if installed. In addition, when the capacitance increases, it is necessary to reduce the inductance value of the harmonic suppression filter in consideration of the influence of the voltage drop. In this case, however, the suppression effect of the filter is reduced, and there is a problem that the resonance cannot be suppressed even with a damping resistor. .

  The present invention has been made in view of the above-described conventional technical problems, and an object thereof is to provide an elevator control device that has a harmonic suppression filter that does not require a damping resistor and can be downsized.

  The elevator control device according to the first aspect of the present invention includes a harmonic suppression filter configured by only a reactor and a capacitor connected to a commercial power supply, and converts alternating current into direct current connected to the harmonic suppression filter. Converter, AC current detecting means for detecting current flowing on the AC side of the converter, current control means for obtaining a voltage command by feedback control calculation based on the current detection signal detected by the AC current detecting means, and the current A resonance frequency transmission filter that transmits at least the resonance frequency from the detection signal and a voltage command output from the current control means are added to cancel the resonance frequency component output from the resonance frequency transmission filter, and a final voltage command is output. Adding means for performing PWM control on the converter based on the final voltage command; It includes those were.

  According to a second aspect of the present invention, there is provided the elevator control apparatus according to the first aspect, wherein the resonance frequency component output from the resonance frequency transmission filter is compared with a reference value, and the resonance frequency component is determined based on the comparison result by the comparison means. And a protection means for protecting the converter when the value is equal to or greater than a reference value.

  According to a third aspect of the present invention, in the elevator control device according to the first aspect, a specific frequency transmission filter that transmits a specific frequency from the current detection signal detected by the alternating current detection means, and an output signal of the specific frequency transmission filter are provided. Comparing means for comparing with a reference value, and protective means for protecting the converter when the output signal of the specific frequency transmission filter is equal to or higher than a reference value based on a comparison result by the comparing means It is.

  According to a fourth aspect of the present invention, in the elevator control device according to the first to third aspects, the adding means includes a phase lead compensator that provides phase lead compensation to the resonance frequency component output from the resonance frequency transmission filter, and An adder that adds a resonance frequency component to which the phase lead compensation output from the phase lead compensator is given to the voltage command output from the current control means is canceled and outputs a final voltage command; A high frequency current detecting means for detecting a frequency and a signal level with respect to a resonance frequency component output from the resonant frequency transmission filter, and an optimum setting value for the phase lead compensation is calculated from the frequency and the signal level detected by the high frequency current detecting means. And phase compensation correction means for correcting a set value of the phase advance compensator.

  According to the first aspect of the present invention, the alternating current detection means detects the alternating current flowing through the primary side of the converter, and the current control means performs a feedback control calculation on the current detection signal and outputs a voltage command. The resonance frequency component is extracted from the current detection signal by a resonance frequency transmission filter, added to the voltage command output from the current control means so as to cancel the resonance frequency component, and the converter is feedforward controlled based on the addition result. By doing so, resonance can be suppressed without using a damping resistor, and the device can be miniaturized.

  According to the second aspect of the present invention, the resonance frequency component of the alternating current is compared with the reference value, and if the resonance frequency component is equal to or higher than the reference value, the converter is protected to prevent the failure of the device. it can.

  According to the invention of claim 3, when the converter becomes uncontrollable due to some influence, the magnitude of the current near the resonance frequency component is monitored and the protection operation is performed, and the signal other than the resonance frequency range such as noise is detected. An erroneous stop of the control device can be prevented.

  According to the fourth aspect of the present invention, the frequency and signal level are detected by the high frequency current detection means from the resonance frequency component output from the resonance frequency transmission filter that transmits at least the resonance frequency from the current detection signal, and the high frequency current detection means The optimum setting value of the phase lead compensation means can be calculated from the detected resonance frequency component, and the setting correction value of the phase lead compensation means can be automatically adjusted, so that phase compensation can be performed even if the resonance frequency fluctuates during operation. The optimum value can always be maintained. As a result, the resonance can be reliably suppressed without using a damping resistor in the harmonic filter portion, and the device can be downsized by eliminating the need for a damping resistor in the harmonic filter portion. Can be planned.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (First Embodiment) An elevator control apparatus according to a first embodiment of the present invention will be described with reference to FIG. A converter 4 is connected to the commercial power supply 1 through a harmonic suppression filter 2 constituted by reactors L1 and L2 and a capacitor C. The damping resistor R of the harmonic filter 2 connected in the conventional example shown in FIG. 8 is omitted. Current detectors 3 a and 3 b are provided between the harmonic suppression filter 2 and the converter 4, and their outputs are given to the arithmetic device 8. The output of the arithmetic unit 8 is given to the converter 4. The converter 4 supplies the output to the inverter 6 via the smoothing capacitor 5. The output of the inverter 6 is supplied to the motor 7. A car 9 and a counterweight 11 are connected by a main rope 10 and a compensator 12, and the compensator 12 is connected through a compensator 13. The car 8 is moved up and down by hoisting and lowering the main rope 10 with a rotation of the motor 7.

  The arithmetic unit 8 uses the currents IuF and IwF detected by the current detectors 3a and 3b and the IvF obtained from the detected currents IuF and IwF to perform two-phase conversion by the three-phase to two-phase converter 81, and the d axis, q The shaft currents IdF and IqF are calculated. The thus calculated currents IdF and IqF and the current commands Idc and Iqc are PI-controlled by the PI controllers 82a and 82b to obtain Vdc and Vqc as d-axis and q-axis voltage commands. On the other hand, the d-axis and q-axis IdF and IqF are also input to the filters (FIL) 83a and 83b. Outputs of the filters 83a and 83b are connected to phase compensators 84a and 84b.

  The outputs of the phase compensators 84a and 84b are added to the voltage commands Vdc and Vqc which are the outputs of the PI controllers 82a and 82b, and the result is converted into three phases by the two-phase to three-phase converter 85, and the three-phase voltage command Vuc. , Vvc, Vwc are calculated. From the calculated voltage commands Vuc, Vvc, and Vwc, the PWM control circuit 86 generates a gate signal for the switching element of the converter 4, thereby performing switching control of the converter 4 and performing power supply control.

  FIG. 2 shows an example of frequency and phase characteristics of the filters (FIL) 83a and 83b. FIG. 3 shows an example of frequency and phase characteristics of the PI controllers 82a and 82b.

The example of the setting frequency of the filters 83a and 83b is shown. If the power supply frequency is 50 Hz, the resonance frequency is 2.07 kHz (13000 rad / s) on the dq axis. If the cut-off frequency (ωc) is set at about 1/10 of that, 207 Hz (1300 rad / s) is obtained. The gain setting values of the phase compensators 84a and 84b are determined as follows. The phase advance angle θ1 of the filters 83a and 83b is
[Equation 2]
tanθ1 = 1300/13000 = 0.1 (θ1 ≒ 0.6 °)
It becomes.

For example, if the PI controllers 82a and 82b have a response frequency of 1500 rad / s, the phase delay with respect to the resonance frequency of 13000 rad / s is
[Equation 3]
tanθ2 = 1500/13000 = 0.12 (θ2 ≒ 0.66 °)
It becomes.

  In order to cancel the signal on the PI controller 82a, 82b side and the signal on the feedforward side with respect to the current of the resonance frequency, a delay of 0.66 ° on the Pl controller 82a, 82b side as shown in FIG. On the other hand, since the feed forward side is advanced by 0.6 °, it is compensated by applying a gain of 1.2 times. Further, by adding to the voltage commands Vdc and Vqc in opposite phase to the resonance frequency components extracted by the filters 83a and 83b, the vibration components are canceled out and the resonance current is suppressed.

  As described above, according to the first embodiment, the resonance can be reliably suppressed without using a damping resistor, and the control device can be downsized because the damping resistor is not provided as a circuit element. It becomes.

  (Second Embodiment) Next, an elevator control apparatus according to a second embodiment will be described with reference to FIG. The overall apparatus configuration of the second embodiment is the same as that of the first embodiment shown in FIG. The second embodiment is characterized by the internal configuration of the arithmetic unit 8. FIG. 5 shows the internal configuration of the arithmetic unit 8. Compared to the configuration of the arithmetic unit 8 shown in FIG. 1, comparators (CMP) 87a and 87b, a reference signal generator 88, and a protection circuit 89 are added. Has been.

  The reference signal generator 88 outputs a set value for overcurrent detection as a reference signal. The comparators 87 a and 87 b receive the outputs of the d-axis signal side and q-axis signal side filters (FIL) 83 a and 83 b and compare them with the reference signal output from the reference signal generator 88. The outputs of the comparators (CMP) 87 a and 87 b are input to the protection circuit 89. When a protection signal is output from the protection circuit 89, the system is stopped.

  Next, the operation of the elevator control device of the second embodiment will be described. Since the filters 83a and 83b detect the current component of the resonance frequency, this component increases when the resonance cannot be suppressed. The outputs of the filters 83a and 83b and a reference signal as a set value for overcurrent detection are compared in advance by comparators (CMP) 87a and 87b. When the comparison result exceeds the set value, the outputs of the comparators 87a and 87b become active. The protection circuit 89 takes in the outputs of the comparators 87a and 87b under an OR condition, and when one of the signals becomes active, the output of the protection circuit 89 is activated and the system is stopped. In order to realize the protection function, the detection currents Iu and Iw may be connected to the comparator after passing through the high-pass filter.

  As described above, according to the second embodiment, in an elevator control device that suppresses resonance without using a damping resistor, when the control becomes impossible due to some influence, harmonics including resonance frequency components are included. By monitoring the magnitude of the current of the wave component and performing a protection operation, it is possible to prevent a failure of the control device.

  (Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. The overall apparatus configuration of the elevator control apparatus of the third embodiment is the same as that of the first embodiment shown in FIG. The third embodiment is also characterized by the internal configuration of the arithmetic unit 8. FIG. 6 shows the internal configuration of the arithmetic unit 8. Compared to the configuration of the arithmetic unit 8 of the first embodiment shown in FIG. 1, comparators (CMPs) 87a and 87b, reference signal generation are shown. A device 88 and a protection circuit 89 are added, and in addition, bandpass filters (FIL2) 810a and 810b are added.

  In the third embodiment, the output of the three-phase to two-phase converter 81 is input to the added bandpass filters (FIL2) 810a and 810b, and the outputs of the bandpass filters (FIL2) 810a and 810b are compared with each other. (CMP) 87a and 87b are inputted. Comparators (CMP) 87 a and 87 b compare the outputs of the filters 810 a and 810 b with the reference signal from the reference signal generator 88. The function of the protection circuit 89 is the same as that of the second embodiment.

  Next, the operation of the elevator control device of the third embodiment will be described. Since the filters 83a and 83b are band-pass filters that transmit only the current in the vicinity of the current component of the resonance frequency, if the resonance cannot be suppressed, the frequency band component increases. By using the filters 810a and 810b as band-pass filters, it is possible to prevent transmission of noise in other frequency regions other than the resonance frequency band. The comparators 87a and 87b compare the outputs of the filters 810a and 810b with the reference signal output from the reference signal generator 88 as a preset value for overcurrent detection. When the comparison result exceeds the set value, the outputs of the comparators 87a and 87b are made active. The protection circuit 89 takes in the outputs of the comparators 87a and 87b under the OR condition, and when one of the signals becomes active, activates the output of the protection circuit 89, and stops the system as in the second embodiment.

  As a configuration of the third embodiment, it is possible to connect the detection currents Iu and Iw to a comparator through a band pass filter.

  As described above, according to the third embodiment, in a control device that suppresses resonance without using a damping resistor, the magnitude of the current in the vicinity of the resonance frequency component when the control device becomes uncontrollable due to some influence. Can be monitored and protected, and an erroneous stop of the control device due to detection of a disturbance signal other than the resonance frequency band such as noise can be prevented.

  (Fourth Embodiment) Next, an elevator control apparatus according to a fourth embodiment of the present invention will be described with reference to FIG. The overall apparatus configuration of the elevator control apparatus of the fourth embodiment is the same as that of the first embodiment shown in FIG. The fourth embodiment also has a feature in the internal configuration of the arithmetic unit 8. FIG. 7 shows the internal configuration of the arithmetic device 8. A high-frequency detector 811 and a phase compensation corrector 812 are added to the configuration of the arithmetic device 8 of the first embodiment shown in FIG. Has been. The outputs of the filters (FIL) 83 a and 83 b on the d-axis signal side and the q-axis signal side are connected to a high-frequency current detector 811 to which the outputs are added, and the output is input to the phase compensation corrector 812. The output of the phase compensation corrector 812 is connected to the phase compensators 82a and 82b as the correction signals a and b, and the setting is changed.

  Next, the operation of the fourth embodiment will be described. The resonance frequency has some frequency fluctuations depending on the external power supply state and the circuit to be configured. The high-frequency current detector 811 detects the outputs of the filters (FIL) 83 a and 83 b as current levels for each frequency, and outputs the detected frequency and current level to the phase compensation corrector 812. The phase compensation corrector 812 checks, for example, the input frequency and current level, selects the largest one near the preset cutoff frequency (ωc), and selects the frequency component from the filter characteristics shown in FIGS. The phase lag in the PI control and the phase advance due to the filter are calculated, and the set value of the phase compensation is calculated. The result is output to the phase compensators 84a and 84b as correction signals a and b. Thereby, the phase compensators 84a and 84b can always keep the set value of the phase compensation optimal.

  As described above, according to the fourth embodiment of the present invention, even if the resonance frequency fluctuates during the elevator operation, the phase compensation can be kept at the optimum value accordingly, thereby using the damping resistor. Without being necessary, the resonance can be reliably suppressed, and the control device can be miniaturized because it is not necessary to provide a damping resistor that is conventionally required as a circuit element.

The block diagram of the 1st Embodiment of this invention. The frequency and phase characteristic figure of the resonant frequency transmission filter in 1st Embodiment. The frequency and phase characteristic figure of PI controller in a 1st embodiment. FIG. 3 is a vector diagram of phase compensation according to the first embodiment. The block diagram of the arithmetic unit in the 2nd Embodiment of this invention. The block diagram of the arithmetic unit in the 3rd Embodiment of this invention. The block diagram of the arithmetic unit in the 4th Embodiment of this invention. The block diagram of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Commercial power supply 2 ... Harmonic suppression filter 3 ... Current detector 4 ... Converter 5 ... Capacitor 6 ... Inverter 7 ... Motor 8 ... Arithmetic device 9 ... Car 10 ... Main rope 11 ... Counterweight 12 ... Compensation 13 ... Compensation 81 ... 3-phase to 2-phase converters 82a, 82b ... PI controllers 83a, 83b ... filters 84a, 84b ... phase compensator 85 ... 2-phase-3 phase converter 86 ... PWM control circuits 87a, 87b ... comparator 88 ... reference Signal generator 89 ... protection circuits 810a, 810b ... filter 811 ... high frequency current detector 812 ... phase compensation corrector

Claims (4)

A harmonic suppression filter composed only of a reactor and a capacitor connected to a commercial power source;
A converter connected to the harmonic suppression filter for converting alternating current into direct current;
AC current detection means for detecting current flowing on the AC side of the converter;
Current control means for obtaining a voltage command by feedback control calculation based on the current detection signal detected by the AC current detection means;
A resonance frequency transmission filter that transmits at least a resonance frequency from the current detection signal;
An adding means for adding a so as to cancel a resonance frequency component output by the resonance frequency transmission filter to a voltage command output by the current control means and outputting a final voltage command;
An elevator control apparatus comprising: PWM control means for performing PWM control of the converter based on the final voltage command.   Comparing means for comparing the resonant frequency component output from the resonant frequency transmission filter with a reference value, and protective means for protecting the converter when the resonant frequency component is equal to or higher than a reference value based on a comparison result by the comparing means. The elevator control device according to claim 1, further comprising an elevator control device.   From the specific frequency transmission filter that transmits a specific frequency from the current detection signal detected by the alternating current detection unit, the comparison unit that compares the output signal of the specific frequency transmission filter with a reference value, and the comparison result by the comparison unit, The elevator control device according to claim 1, further comprising a protection unit that protects the converter when an output signal of the specific frequency transmission filter is equal to or higher than a reference value. The adding means outputs a phase advance compensator that gives phase advance compensation to the resonance frequency component output from the resonance frequency transmission filter, and outputs the phase advance compensator in response to a voltage command output from the current control means. It consists of an adder that adds so as to cancel the resonance frequency component given phase lead compensation and outputs the final voltage command,
A high frequency current detecting means for detecting a frequency and a signal level with respect to a resonance frequency component output from the resonant frequency transmission filter, and an optimum setting value for the phase lead compensation is calculated from the frequency and the signal level detected by the high frequency current detecting means. The elevator control device according to claim 1, further comprising phase compensation correction means for correcting a set value of the phase advance compensator.

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