JP2667907B2 - Elevator control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an elevator control device for driving a car to land on a rescue exit during a power outage.

[Conventional technology]

As described in Japanese Patent Application Laid-Open No. Sho 63-174584, a conventional device detects an electric motor that generates a driving force of an elevator in a power generation state and consumes regenerative power by a resistor. .

Secondly, as disclosed in Japanese Patent Laid-Open No. 63-234880, it has been proposed to generate positive and negative reverse DC voltages within the same short chopping cycle.

[Problems to be solved by the invention]

The first prior art described above does not take into consideration the fact that when the operating state of the electric motor shifts from the running state to the regenerative state, the fluctuation of the DC voltage output from the first power converter increases. This has affected the current control performance of DC current.

Further, the second prior art has a problem in that the DC power supply is damaged and its life is shortened in a load state where the load is swung by the load.

An object of the present invention is to reduce the influence on the direct current control performance, perform a stable ride comfortably, and perform highly reliable automatic landing operation during an electric power failure of an elevator.

[Means for solving the problem]

The present invention provides a method for controlling the first power converter 2 when the DC power is lost.
A DC power source connected between two AC terminals, a power consuming element connected between two different AC terminals of the first power converter, and an ignition period of a self-extinguishing element in the first power converter A first mode in which a direct current power source supplies power to the electric motor within a predetermined period Tc, a second mode in which electric power generated by the electric motor is consumed by a power consuming element, and a first power conversion Control means having a third mode in which electric power generated by the electric motor is circulated by short-circuiting the DC terminals of the electric machine, and means for controlling the speed of the elevator by changing the time relationship of the modes. I do.

[Action]

With such a configuration, when a power failure occurs, the AC power supply is disconnected from the first power converter, and the DC power supply and the resistor are connected instead. Due to the power failure, the ignition control of the self-extinguishing element of the first power converter is performed within one cycle by the first power converter.
The power supply mode, the second power generation mode, and the third recirculation mode are provided, and by controlling the time relationship among them, it is possible to perform stable, comfortable ride, and highly reliable automatic landing control during a power failure.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an elevator control device suitable for carrying out the present invention. The main circuit is generated when the AC power source 1, the touch device 2 that opens when a power failure occurs, the first power converter 4 that is configured by the self-extinguishing elements G _{1 to} G ₆ , and the self-extinguishing element is ignited. A capacitor 3 for absorbing overvoltage, a reactor 5 for smoothing a direct current, a second power converter 6 for producing an alternating current of an arbitrary frequency,
And a capacitor 7 for reducing harmonic components contained in the AC power output from the second power converter 6. The first power converter 4 controls the DC voltage E _d to control the ignition of the self-turn-off devices G ₁ ~G _6. This allows DC current
Adjust the amount of I _d, the second power converter 6 controls the magnitude of the alternating current output.

The output of the second power converter 6 is supplied to the electric motor 8. The driving force generated in the electric motor 8 is transmitted to the sheave 10 via the speed reducer 9, and is constituted by a rope 20 hung on the roper 10, a counterweight 11 connected to both ends of the rope 20, and a car 12. Power to the elevator. The electric motor 8 is provided with a rotation speed detector 14 for detecting speed and position, generates a pulse P _r proportional to the rotation speed, and sends it to the elevator operation management circuit 22.

The control unit of the present invention includes a DC current detector 21, a control circuit 23 for the second power converter 6, a current control circuit 24, and a control circuit 30 for the first power converter 4. Control circuit 30
The central processing unit 31, the analog / digital converter 32, the storage elements 33 and 34, and the input / output element 35 share the bus 36 for exchanging information. A frequency command * to be output from the operation management circuit 22 in accordance with operation of the elevator, the current command I *, and, for receiving the connexion controls the operation completion signal S ₂ when a power failure. The frequency command * is transmitted to the control circuit 23, and *
Outputs a control signal P ₇ to P ₁₂ corresponding to, and controls the second power converter 6 to obtain the AC power of a predetermined frequency.

Current command I * is transmitted to the current control circuit 24, is compared with the detected value I _r of the DC current I _d by the DC current detector 21, I
* Voltage corresponding to the DC voltage E _d to maintain the command E *
Put out. The control circuit 30 receives the E *, issues a firing pulse P ₁ to P ₆ point corresponding to the command. Thus the first self turn-off devices G ₁ ~G ₆ of the power converter 4 is driven via the drive circuit 25 controls the E _d.

Interruption of the AC power supply 1, a transformer 15, and is detected by the power failure detection circuit 16 is set to "H" from "L" to the power failure detection signal S _1. Further, the open / close signal S ₀ of the contactors 2 and 17 of the main circuit is issued to operate the contactor 2 to the open circuit side and the contactor 17 to the closed circuit side during a power failure. By the operation described above, the DC power supply 18 and the resistor 19 are connected to the first power converter instead of the AC power supply 1.

The flow chart of the processing of the control circuit 30 is as shown in FIG. When the control circuit 30 starts up, the process 100 is executed and the control circuit 3
If 0 is set, initialization of circuits necessary for normal operation is performed. Next, the process 110 is executed to read the signals S ₁ and S ₂ and the command I *. Thereafter, the process 120 determines whether the operation is the normal operation or the operation during a power failure. The judgment condition is that the power failure is detected when the operation is not completed at the time of the power failure (S ₂ = “L”). If the condition is satisfied, the process 140,
150 is executed. When the condition is not satisfied, the process for normal operation is performed by the process 130, and the output process is performed (process 160).
Proceed to.

The signal S ₂ is output from the operation management circuit 22, and upon completion of landing at the entrance 13 due to operation during a power outage, the signal “L” is output.
From “H” to “H”. The signal S ₂ is the power failure detection circuit 16
Transmitted to, when even if power is restored S ₂ is "L", is used as a control signal the state of the signal S ₀ unchanged.

If the operation is started during a power failure, the process 140 is executed to set the conduction ratio. FIG. 3 is a characteristic diagram of the duty ratio data used in the process 140 with respect to the voltage command E *. Figure 3 (a) shows a duty ratio data gamma _a for the DC power supply 18.
Figure 3 (b) shows a duty ratio data gamma _b determining the flowing time of current flowing through the resistor 19. gamma _a is a gamma ₁ is the voltage command E * in the positive maximum value E ₁ *, a negative maximum value E ₂ * gamma ₂
Becomes gamma _b likewise gamma _4, a gamma _3. Thus, the processing 140 is set for γ _a and γ _b corresponding to the voltage command E *.

In processing 150, the ignition pulse width of the self-extinguishing element is set based on γ _a and γ _b . Self-extinguishing element of first power converter 4
If the firing period of G _{1 to} G ₆ is T _c , and the time for connecting the DC power supply 18 and the time for connecting the resistor 19 are T _a and T _b , respectively, _Ta = γ _a · T _c (1) T _b = γ _b · T _c (2) However, after the pulse width is set so as to satisfy T _c ≧ T _a + T _b (1) and (2), the processing is performed. Step 160 is executed to process the generation of the firing pulse. FIG. 4 is a state of occurrence of firing pulses P ₁ to P _6. Firing pulse P ₁ to P ₆ are each corresponding to the operation of the self-turn-off devices G ₁ ~G _6. To firing period T _c in the figure, P ₁ at the beginning
Applying a voltage from the time t ₀ by the DC power supply 18 to the "H" up to t _1. This time is equal to T _a. Then, the P ₁ from time t ₁ to the "L" add resistor 19 in the circuit as a P ₃ "H". Continue this state until time t _2. Thus only during the T _b, direct current to the resistor 19 can flow. T ₃ from the time t ₂ is Sakutsu reflux for a firing pulse P ₂ and P ₅ as "H".
Waveform of the DC voltage E _d at this time is the form that is shown in Figure 4. From time t ₀ to t ₁ according the voltage E _d of DC power supply 18.
Then, from time t ₁ to t ₂ results in resistor 19 voltage I _d · R
Appears. From t ₂ to t ₃ is the E _d is 0 to reflux.
If the average DC current and _d, the average DC voltage _d is _{d = γ a · E b -γ} b · d · R ... (3) the current Waseru. From equation (3), if _d is desired to be positive, γ
_a can be increased, and conversely, if _{d is} to be negative, γ
_It is good to make _b large.

When the process 160 is completed, the process 170 is executed, and the process is adjusted to perform the processes 110 to 160 at predetermined intervals (in this embodiment, at every _Tc ). After the adjustment is completed, the process returns to the process 110, and the above process is repeated.

As described above, according to the present embodiment, since the same power control is performed in all regions regardless of the operation state of the motor, _d /
E * does not become discontinuous and does not disturb the current control system. Further, even if the current is about to drop in the negative region of E *, the DC power supply has a constant voltage, so that the DC current is not interrupted, an overvoltage is not generated in the main circuit, and a highly stable control device can be obtained.

〔The invention's effect〕

ADVANTAGE OF THE INVENTION According to this invention, riding comfort is stable, and automatic landing operation at the time of a power failure of a highly reliable elevator can be performed.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of an elevator control apparatus according to an embodiment of the present invention, FIG. 2 is a processing flow chart of the control circuit 30 of FIG. 1, and FIG. 3 is a flow rate in processing 140 of FIG. FIG. 4 is an explanatory diagram of the voltage command, and FIG. 4 is a state of the ignition pulses P _{1 to} P ₆ and the DC voltage E _d for igniting and extinguishing the self-extinguishing elements G _{1 to} G ₆ of the power converter 4 of FIG. FIG. 1 ... AC power supply, 2, 17 ... Contactor, 4 ... First power converter, 16 ... Power failure detection circuit, 18 ... DC power supply, 22 ... Operation management circuit, 24 ... Current control circuit , 30 ... The control circuit for the first power converter.

Continuation of front page (72) Inventor Shunsuke Mine 1070 Mo, Katsuta-shi, Ibaraki Mito Plant, Hitachi, Ltd. (56) References JP-A-53-7050 (JP, A) JP-A-61-248881 ( JP, A) JP 59-207375 (JP, A) JP 2-147581 (JP, A)

Claims (1)

(57) [Claims] 1. A first power converter that comprises a main circuit with a self-extinguishing element to convert AC power into DC power, a ballast that suppresses fluctuations of DC current in the DC power, and the DC power. A second power converter for converting AC power into an AC power of an arbitrary frequency, and an elevator drive electric motor fed by the second power converter, wherein the first power converter and the second power converter In an elevator control device for controlling the operation of an electric power generator to control the speed of an elevator car, a DC power supply connected between two AC terminals of the first power converter when the AC power disappears, and Control means for controlling the ignition period of the power consuming element connected between two different AC terminals of the first power converter and the self-extinguishing element in the first power converter, the control means having a predetermined cycle. From the DC power source every Tc A first mode for supplying power to motive, a second that consumes power generated by the said electric motor in said power element
And a control means having a third mode in which the electric power generated by the electric motor is circulated by short-circuiting between the DC terminals of the first power converter and the speed of the elevator by changing the time relationship between the modes. A control device for an elevator, comprising: means for controlling.