JPH04236181A - Controller for elevator - Google Patents

Abstract

PURPOSE:To effectively use recovery energy by absorbing the energy by a capacitor and returning it to a main circuit by using a booster chopper at the time of power drive. CONSTITUTION:Recovery energy is returned in a recovering state, a smoothing capacitor 6 is charged, and a voltage between both ends of the capacitor is raised. Here, if it becomes a certain set value or more, a voltage detector 14 is operated to close a semiconductor switch 15, and the energy is absorbed to a capacitor 16. Then, the charge of the capacitor 16 is stored in the capacitor 6 at the time of power drive, and the energy is supplied. Thus, the energy is not wastefully consumed, but can be effectively used for the power drive, thereby improving the efficiency of the energy.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator control system.

0002

[Prior art] Voltage-type inverters, which are currently the mainstream
Figure 5 shows the main circuit configuration of an elevator using the elevator. 1
is a commercial power supply, 2 is a contact of a magnetic contactor, 3 is a diode rectifier, 4 is a regenerative resistor, 5 is a semiconductor switch for regeneration, 6 is a smoothing capacitor, 7 is a 3-phase inverter bridge, 8 is an induction motor, 9 is a reduction gear, 10 is a main sheave, 11
12 is a counterweight, 13 is a cage, and 14 is a voltage detector.

[0003]Elevators generally have cars 13 for passengers to ride on.
and the counterweight 12 are connected in a hanging manner. Normally, the counterweight is selected to have a weight that balances at about half the capacity, and the elevator operates according to the direction of operation depending on the number of passengers, receiving torque equal to the imbalance between the car and the counterweight. There is.

Therefore, if the car is light relative to its balance, no force is required in the UP direction, and conversely, the D
In the N direction, force must be applied from the electric motor. Similarly, if the car is heavy relative to the balance, no force is needed in the DN direction, but force must be added in the UP direction. In this way, depending on the loading condition of the car and the driving direction, from the electric motor's point of view, there are operations that require more force, and operations that require less force and energy.
Basically, regenerative operation occurs at half the rate. Furthermore, if we consider an ideal situation in which there is no mechanical or electrical loss, and all passengers who ascend an elevator descend from the same place, then according to the law of conservation of energy, the energy consumption will be There will be no. In reality, it is not ideal due to mechanical loss, electrical loss, wind damage, friction, etc., but during regeneration, a corresponding amount of energy is returned. However, the current situation is that this energy during regeneration is hardly used effectively.

[0005] This will be explained using FIG. When the elevator is in transit, energy is supplied from the commercial power source 1 to the electric motor 8 via the rectifier 3 and the inverter 7 to operate the elevator. During regeneration, the motor 8 acts as a generator, so the power rectified by the diode of the inverter 7 charges the capacitor 6, increasing the voltage across the capacitor 6. A voltage detector 14 detects this voltage, and when the voltage exceeds a certain set voltage, a semiconductor switch 5 is turned on. As a result, the regenerated power flows into the regenerative resistor 4, where it is consumed as Joule heat. The consumed power W is expressed by equation (1). R: Regenerative resistance value, I: Resistance current, V1: ON voltage of semiconductor element 5. In this way, regenerative power is normally consumed in the form of Joule heat by a resistor or as heat within a motor. I'm taking it.

[0006]

[Problem to be solved by the invention] High-speed and ultra-high-speed gearless elevators may have a system that regenerates power from commercial power, but the number of such elevators is small, and the customer does not use a reverse-type wattmeter. The current situation is that it does not directly reduce electricity costs.

[0007]Also, there are proposals to extract this regenerated energy and use it for other power sources, hot water heaters, etc., but the energy supplied varies and there is not necessarily a reasonable load that can be used effectively. There is also a method of supplying regenerated energy to the elevators in the car mode at the same time from several elevators at once, but multiple elevators are required to be effective. However, there is not necessarily a good balance between regeneration and power generation, and the scale of the system also increases. Also, a battery is connected in parallel to the smoothing capacitor of the main circuit.
A system has also been proposed that absorbs regenerative energy by connecting a The number will also increase. Another method is to increase the capacitance of the smoothing capacitor, but this is also not practical as the capacitance would have to be extremely large to absorb sufficient regenerative energy.

[0008] As described above, in the current system, the reality is that the returned energy cannot be used unless the energy is exhausted or a fairly large system is configured. There was a growing demand for ways to effectively utilize this technology. SUMMARY OF THE INVENTION An object of the present invention is to provide an elevator control device that effectively uses regenerated energy in order to solve the above-mentioned problems. [Structure of the invention]

[0009]

[Means for Solving the Problems] The present invention provides a capacitor that absorbs regenerative energy, a semiconductor switch that controls it, a voltage detector that detects reactor voltage that suppresses inrush current, and supplies the absorbed energy. Consists of a boost chopper.

0010

[Operation] Detects that the voltage across the smoothing capacitor has increased due to regenerated energy, turns on the semiconductor switch, and absorbs the energy into the capacitor. This energy is returned to the main circuit using a step-up chopper during operation.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An elevator control system according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. 15 is a semiconductor switch element, 16 is a capacitor 17 and 48 are reactors, 18 is a semiconductor switch element, 19 is a diode, and 20 is a voltage detector.

Other omitted parts are the same as those in FIG. 5. Figure 2 shows a control circuit for regenerative energy absorption. 21
, 23, 25, 27 are fixed resistors, 22 is a variable resistor, 24
2 is a Zener diode, 26 is a photocoupler, and 28 is a power source for driving 15 semiconductor switches.

Further, FIG. 3 shows a control circuit for a booster chopper that supplies energy when the motor is moving. 29, 35, 45 are photocouplers, 30, 32, 34, 36, 48, 50, 3
7, 38, 39, 44, 46 are fixed resistors 31, 49 are variable resistors 51, 33 are Zener diodes, 40 is a power supply for the control circuit, 41 is an inverter element, 42 is an AND element,
43 is an oscillator, and 47 is a power source for driving 18 semiconductor switches.

First, in a regenerative state, regenerative energy returns, the smoothing capacitor 6 is charged, and the voltage across both ends rises. When the voltage exceeds a certain set value, the voltage detector 14 operates to turn on the semiconductor switch 15, and the regenerated energy is absorbed into the capacitor 16. 48 is a reactor that suppresses the rush current at this time. The operation of this circuit will be explained with reference to FIG. The voltage across capacitor 6 is 21,
The voltage is divided by a fixed resistor 23 and a variable resistor 22, and when this value exceeds the voltage of the Zener diode 24, a current flows through the resistor 25 to the primary side of the photocoupler 26. As a result, the transistor on the secondary side of the photocoupler is turned on, and the bases and gates of the 15 semiconductor elements (IGBT, TR, etc.) are connected from the power supply 28 through the resistor 27.
Power is supplied to the device and the device is turned on. This charges 16 capacitors. The charging current is suppressed by 48 reactors. Therefore, at this time, the capacitance C of the capacitor is selected to a value that satisfies equation (2): W≦1/2CV1 2 (2) W: regenerative power, V1: 15 ON voltage (2) to absorb the regenerative power.

Next, when this regenerated power is supplied during row 5, the voltage across the capacitor 6 drops due to row 5. This is set to a value that is detected when the value divided by the fixed resistors 48 and 50 and the variable resistor 49 becomes less than the Zener diode voltage 51. Also, in order to confirm that the regenerated power is being charged at this time, the voltage across the capacitor 16, divided by the fixed resistors 30 and 32 and the variable resistor 31, must be equal to or higher than the Zener voltage 33. Check.

Due to these conditions, the photo coupler 29 is OFF and the photo coupler 35 is ON, the secondary side of the photo coupler 35 is at a low level, and the output of the inverter 41 is at a high level. Since the secondary side of photocoupler 29 is also at a high level, 4
The output of the AND of 2 also becomes high level. When this enters the oscillator 43, it oscillates at a certain period. This oscillation is 4
The 18 semiconductor switching elements are turned on and off via the 5 photocouplers.

FIG. 4 shows this state. 18 manipulates ON and OFF in a certain cycle. As a result, when 18 is ON, the charge in capacitor 16 flows into 18 through reactor 17. IQ18 indicates this current. When 18 of them turns off, the current tries to continue flowing due to the energy stored in the reactor, so it flows through diode 19 and into capacitor 6.
Eventually, the energy will decrease and the current will no longer flow. Then, 18 is turned ON again and the same operation is repeated. Due to this action, the charge of capacitor 16 is injected into capacitor 6, supplying energy. As shown in FIG. 4, the charge on the capacitor 16 gradually decreases, so the voltage decreases and each current also decreases. Then, when the voltage across 16 decreases and the detected divided voltage value becomes less than the zener voltage of 33, the operation ends.

[0019]

[Effects of the Invention] According to the present invention, regenerated energy can be effectively utilized for power driving instead of being wasted, and energy efficiency can be improved.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an elevator control device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram of a regenerative power absorption circuit according to the present invention.

FIG. 3 is a circuit diagram of a regenerative power supply circuit according to the present invention.

FIG. 4 is a waveform diagram of each part of the power supply circuit according to the present invention.

FIG. 5 is a configuration diagram of a conventional main circuit.

[Explanation of symbols]

1...Commercial power supply 2...Magnetic contactor 3...Diode rectifier 4...Regenerative resistor 5...Semiconductor switch element 6...Smoothing capacitor 7...3-phase inverter bridge

Claims (1)

[Claims] 1. A main circuit of a voltage source inverter having a DC smoothing capacitor, a first voltage detector that detects the voltage of the DC bus of the main circuit, and a regenerative power absorption capacitor that absorbs regenerated power, connected in series. a control device that controls the semiconductor switch based on the connected semiconductor switch element and reactor and the output of the voltage detector; a second voltage detector that detects the voltage of the regenerative power absorption capacitor; and the first voltage detector. A control device for an elevator, comprising: a step-up chopper that supplies charging of the regenerative power absorption capacitor to the DC smoothing capacitor based on the output signal of the voltage detector and the output of the second voltage detector.