JPS6253192A - Controller for elevator - Google Patents

Abstract

PURPOSE:To reduce electromagnetic noise, and to minimize a radionoise into a residence space in a housing, in which an elevator is installed, by connecting controllers at an input end and an output end for a current type inverter device. CONSTITUTION:Output currents are levelled by the charge and discharge functions of a capacitor 22 connected at an output end for a current type impedance device 7, and formed to a current waveform close to a sine wave. Even in a converter section 71, on the other hand, currents of a waveform close to the sine wave flow through the AC power supply 5 side by the working of a capacitor 21 connected at an input end for the current type inverter device 7. According, higher harmonic noises in a main circuit wiring connecting an AC power supply, the inverter device and an induction motor can be reduced largely, the mixing-in of higher harmonic noises to wirings in a control panel for a signal controller, etc. by electromagnetic induction is prevented, and a radio noise into a housing can be obviated.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to a control device for an AC elevator.

In particular, the present invention relates to an AC elevator control device using a current source inverter device having a current control function.

[Background of the invention]

In recent years, a method has been developed to control an induction motor for driving an elevator using a frequency conversion device (hereinafter referred to as an "inverter device") that inputs AC power and outputs variable frequency power (Utility Model Application No. 56-132274). By varying the output frequency of the inverter device, the induction motor can be controlled very efficiently from start to stop of the elevator, resulting in power savings and high accuracy.

FIG. 2 shows an example of an elevator control system using a conventional voltage source inverter device.
AC power is supplied via E6. The voltage source inverter device 6 includes a converter section 61 that converts AC power to DC power, a smoothing capacitor 62, and an inverter section 63 that converts DC power to AC power. In addition,
24 and 25 are a discharge circuit and its control device for protecting the smoothing capacitor 62 during regenerative operation.

Next, FIG. 3 shows the layout of an elevator in a building using the above control device. In the control panel 31, in addition to the voltage type inverter device 6 and the speed command device 12, a signal control device W111 that determines the service floor of the elevator and generates a signal in accordance with this is installed 6. A retail cord 8 extends from the signal control device 12 to the passenger car 1, and transmits signals or supplies power to the passenger car 1. This tail cord 8 is a moving cable and moves up and down in the hoistway according to the movement of the seat 1. On the other hand, signals are transmitted to the hall operating equipment 9 via the building wiring 10 to the building.

In an elevator equipped with a control device configured as described above, the problem of electromagnetic noise generated due to the operation of the voltage source inverter device 6 will be considered.

In FIG. 2, an inverter section 63 of a voltage source inverter device 6 converts a constant DC voltage stored in a smoothing capacitor 62 into an AC voltage using a pulse width control (PWM) method. FIG. 4(a) shows a voltage wave under PWM control, which is switched at high frequency so that the pulse width distribution becomes close to a sine wave. Figure 4 (b
) is a trace of the actual waveform photograph of the voltage source inverter device shown in FIG. 2, and it can be seen that a sinusoidal current containing harmonics flows through the induction motor 4 due to the PWM-controlled voltage waveform.

As described above, in the conventional voltage source inverter device, both voltage and current include many harmonics.

Due to the influence of these harmonics, harmonic noise is mixed into the wiring in the control panel such as the signal control device 11 that is close to the control panel due to electromagnetic induction. The noise generated inside the control panel is
It will be discharged into the building via the tail cord 8, building wiring 10, and landing operating equipment 9 shown in FIG. In particular, the tail cord 8 changes its position and shape in various ways as the passenger car 1 moves, and acts as an antenna that strongly radiates electromagnetic noise generated in the wiring inside the control panel of the signal control device 11 etc. that leads to the tail cord 8. .

In this way, the electromagnetic noise generated by the operation of the inverter device for controlling the elevator drive induction motor is propagated into the building via the tail cord and building wiring.
Interfering with the operation of radios, televisions, stereos, etc. in the building,
Directly impact the lives of residents. In particular, the influence on the operation of highly sensitive information equipment such as office automation equipment and highly sensitive medical equipment, which have been rapidly increasing recently, is significant.

On the other hand, in FIG. 2, voltage source inverter device I! Also in the converter section 61 of No. 6, a current with harmonic components due to three-phase full-wave rectification flows, and noise may be mixed into the power supply line. Noise mixed into the power supply line is emitted into the building through the tail cord that supplies power to the first power source, and is also transmitted to the TV and OA equipment 3 in the living room via the building lead-in line 32 and the power transformer 33-34 in Fig. 3.
This will affect the 5th grade.

As mentioned above, in elevators that are installed and used very close to human living spaces, when the induction motor for driving the elevator is controlled by an inverter, radio wave interference due to electromagnetic noise generated due to the operation of the inverter device is caused. This is becoming a big problem. As a means to improve this, it is possible to insert a reactor 26 into the output line as shown in FIG. 2, but even with this, the voltage waveform of the voltage source inverter device 6 can hardly be improved.

[Purpose of the invention]

In view of the above-mentioned problems specific to inverter-controlled elevators, it is an object of the present invention to control elevators that have a low level of electromagnetic noise even when using an inverter device, and that cause less interference with radio waves in living spaces in buildings. The goal is to provide equipment.

[Summary of the invention]

A feature of the present invention is that an induction motor for driving an elevator is controlled by a current source inverter device having a current control function, and a capacitor is connected to an input terminal and an output terminal of the current source inverter device. By reducing electromagnetic noise associated with control,
This is because it reduces radio wave interference to the living space inside the building where it is installed.

[Embodiments of the invention]

FIG. 1 shows an embodiment of an AC elevator control device according to the present invention. In the figure, 7 is a current source inverter device, 2
1.22 is a capacitor, 13 is a speed control device, 14 is a converter control device, and 15 is an inverter control device.

The current source inverter device 7 includes a converter section 71 and a smoothing reactor 72 that can convert AC power to DC power and control the magnitude of the current, and an inverter section 73 that converts DC power to AC power of an arbitrary frequency. Become. The rest is the same as in FIG. 2.

In FIG. 1, the speed control bag [13 is the speed command device 1
A speed command signal from 2 and a speed feedback signal from speed detector 16 are input, and signals are generated to converter control device 14 and inverter control device 15 according to the deviation. The converter control device 14 and the inverter control device 15 are
The converter section 71 and the inverter section 73 are controlled based on the signal from the speed control bag [13], and the supply voltage and frequency of the current source inverter device 7 are varied.

At this time, the inverter section 73 performs PWM control like a conventional voltage type inverter device.

A pulse current 51 whose average value is sinusoidal as shown in FIG. 5(,) is output. This pulse current 51 is a current source inverter device! Capacitor 22 connected to the output terminal of 7
is averaged by the charge/discharge function of , resulting in a current waveform close to a sine wave as shown at 52 in FIG. 5(a).

On the other hand, in the converter section 71 as well, due to the action of the capacitor 21 connected to the input end of the current source inverter device 7, a current flows to the AC power source 5 side with a waveform close to a sine wave.

Figure 5(b) is a trace of the input/output voltages, input/output currents, and waveform photographs on the AC power supply 5 side and induction motor 4 side of the capacitors 21 and 22 connected to the current source inverter device shown in Figure 1. be. Each waveform is extremely smooth and has very few harmonics. In this way, by connecting the capacitors 21 and 22 to the input and output ends of the current source inverter device 7, variable frequency power having an input/output waveform close to a sine wave can be obtained.

Further, when a current source inverter device such as the embodiment shown in FIG. 1 is used, the current value of the DC power input to the inverter section 73 can be controlled by the converter section 71. Therefore, the relationship between the pulse current 51 shown in FIG. 5(a) and the averaged current 52 after passing through the capacitor can be kept almost constant, and a good output waveform can be obtained even during low-speed extra rotation. .

As described above, according to the embodiment shown in FIG. 1, it is possible to significantly reduce harmonic noise in the main circuit wiring connecting the AC power supply, the inverter device, and the induction motor. Prevents harmonic noise from entering the wiring inside the control panel.

It is possible to prevent radio wave interference into the building.

Furthermore, when the control device shown in FIG. 1 is mounted in a control panel, the effect of preventing radio wave interference can be further enhanced by attaching the portion shown by the two-dot chain line in FIG. 1 to a magnetic field. FIG. 6 shows that the main parts of the control device shown in FIG. It is surrounded by a high-quality metal plate 26 and is magnetically shielded. In this way, the main circuit of the current source inverter device can be magnetically interfered with the wiring in the control panel, and it is possible to further prevent noise from entering the wiring in the control panel.

In this embodiment, the current-source inverter device is used to control the elevator-driving induction motor, so the circuit configuration is simpler than that using a conventional voltage-source inverter device. That is, in the conventional voltage source inverter device as shown in FIG. 2, when the elevator performs full load down operation or no load up operation, regenerated power is stored in the smoothing capacitor 62, and as a result, the capacitor voltage increases. There is a risk that the smoothing capacitor 6λ will be destroyed. Therefore, in order to avoid this, in the conventional circuit, when the discharge circuit 24 is set to a dangerous voltage, it is necessary to cause the control device 25 to discharge and consume the voltage.

However, if a current source inverter device is used as in this embodiment, the gate firing phase of the converter section can be controlled by the converter control device during regenerative operation, and no special device is required to process the regenerated power. Therefore, the control device can be configured with small and economical equipment.

Furthermore, in this embodiment, it is possible not only to prevent radio wave interference into the living space, but also to reduce noise during elevator operation compared to those using conventional voltage source inverter devices. Namely.

According to this embodiment, the output waveform from the current source inverter device to the induction motor via the capacitor becomes an extremely smooth waveform as shown in FIG. 5(b).

Therefore, as shown in FIG. 7, the noise of the induction motor can be reduced to the same level as when using commercial power, and the influence of noise on the living space can also be reduced.

〔Effect of the invention〕

According to the present invention, it is possible to realize a control device for a high-precision elevator using an inverter device, which has a very low electromagnetic noise level and causes little radio wave interference to a living space.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of an elevator control device according to the present invention, FIG. 2 is a block diagram showing an elevator control device using a conventional voltage source inverter device, and FIG. FIG. 2 is a diagram showing the wiring inside an elevator building using the control device shown in the figure. Figure 4 shows the output waveforms of the voltage source inverter device in Figure 2, and Figure 5 shows the input/output waveforms on the AC power supply side and induction motor side of the capacitor connected to the current source inverter device in Figure 1. It is a diagram. Furthermore, FIG. 6 shows an example of how the control device shown in FIG. 1 is mounted in a control panel, and FIG. 7 shows the noise of an induction motor when using the elevator control device according to the conventional example and the embodiment shown in FIG. FIG. 1... Car, 2... Counterweight, 3...
Rope, 4... Induction motor, 5... AC power supply, 6...
... Voltage source inverter device, 7... Current source inverter device, 61°71... Converter section, 62... Smoothing capacitor, 72... Smoothing reactor, 63.73.
... Inverter section, 8 ... Tail cord, 9 ... Hall operation device, 10 ... Building wiring, 11 ... Signal control device, 12 ... Speed command device, 13 ... Speed control device , 14... converter control device, 15... inverter control device, 16... speed detection unit, 17.18...
・Main contactor, 19...High speed breaker, 20...Voltage transformer, 21.22...Capacitor, 23...Current transformer, 24...Discharge circuit, 25...Discharge Circuit control device, 26... Reactor, 27... Metal scrap plate, 31.
...Control panel, 32...Building lead-in line, 33°34...
Power transformer, 35...OA equipment, 51...PWM
Pulse current, 52...Current waveform after passing through the capacitor.

Claims (1)

[Claims] 1. An induction motor that drives an elevator car, a speed command device that commands the speed of the induction motor, and a signal transmission or power supply to the elevator car via a tail cord, and A current type device that is equipped with a signal control device that transmits signals to hall operating equipment via building wiring and an AC power source, which inputs AC power from the AC power source and supplies variable frequency power to the induction motor. An elevator characterized in that an inverter device and a speed control device for controlling the current source inverter device according to commands from the speed command device are provided, and capacitors are connected to the input end and the output end of the current source inverter device. Control device. 2. The elevator control device according to claim 1, wherein a shielding plate made of a conductive member is provided on the outside of the capacitor, and the capacitor and the current source inverter device are shielded by the shielding plate. 3. In claim 1 or 2, the current source inverter device includes a converter section that inputs AC electric power and converts it into DC power, a reactor that smoothes the DC power, and a reactor that inputs the DC power. An elevator control device consisting of an inverter section that converts AC power into AC power.