JP2010180003A - Elevator power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elevator power supply apparatus capable of suppressing maximum electric power received from a commercial power supply to contracted power or lower. <P>SOLUTION: The elevator power supply apparatus includes: a current variable rectification means 21 which converts an alternating current of the commercial power supply 10 into a direct current and has a current variable function for a direct current; an inverter 22 for generating an alternating current supplied to a motor 31 from a direct current; an electric double-layer capacitor 23 directly connected between and in parallel with the current variable rectification means 21 and the inverter 22; and a control means 24 which detects the direct current output from the current variable rectification means 21 and controls the current variable rectification means 21 to prevent the electric power received from the commercial power supply from exceeding the contracted power. The electric double-layer capacitor 23 is charged with regenerative electric power during the regenerative operation of the motor 31 and discharges the power during the power running operation of the motor. The electric double-layer capacitor 23 does not need to be separately provided with a charge/discharge control circuit. The elevator power supply apparatus can save electricity charges because it can suppress the maximum electric power received from the commercial power supply to the contracted power or lower. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elevator power supply device, and aims to reduce an electricity bill by utilizing a power storage device.

In a rope type elevator operated by a motor, a rope is wound around a sheave that rotates together with the motor, a car is suspended from one end of the rope, and a weight is suspended from the other end. The weight of this weight is set so that it balances in a state where half of the capacity is on the car.
Therefore, if the running resistance is ignored, if the car rises with more than half the number of passengers in the car or goes down with less than half the number of people in the car, the motor will be powered. On the other hand, when the vehicle rises with less than half the number of passengers on board or descends with more than half the number of people on board, the motor is regeneratively operated.

Attempts have been made in the past to reduce the amount of power used by the elevator and save electricity by storing the regenerative power generated by the motor during regenerative operation in a storage battery and reusing it during powering operation of the motor. Yes.
However, since the power consumption of the elevator is inherently low, the saving effect of the electricity bill when the amount of power used is reduced by using regenerative power is not so great.

Therefore, Patent Document 1 below proposes an elevator driving device that uses a storage battery to keep contract power low. Since the basic electricity bill is determined by the contracted power, if the contracted power can be reduced, a significant saving in the electricity bill can be achieved.
As shown in FIG. 6, this apparatus includes a rectifier 101 that rectifies AC power from a commercial power source 100 and converts it into DC power, a smoothing capacitor 102 that smoothes the DC power, and the smoothed DC power. Inverter 103 for converting to variable voltage / variable frequency three-phase AC power, AC motor 110 to which AC power is supplied from inverter 103, sheave 111 around which the rope is wound, and suspended from one end of the rope A car 112, a weight 113 suspended from the other end of the rope, a storage battery 105 for storing electric power, a charge / discharge circuit 104 of the storage battery 105 comprising a DC-DC converter, and a control device 106 for controlling the charge / discharge circuit 104; It has.

The control device 106 controls the charging of the storage battery 105 from the power supply 100 through the charging / discharging circuit 104, or drives the AC motor 110 (during power running) so that the power supply current from the power supply 100 does not reach the breaking current of the breaker 107. ) To discharge the storage battery 105 and supply electric power to the AC motor 110, or to control the storage battery 105 to be charged with regenerative power when the AC motor 110 is regenerating (during braking).
Therefore, in this device, it is possible to suppress the maximum power received from the commercial power source from exceeding the contract power.
In Patent Document 1, as the storage battery 105, a secondary battery such as a lead storage battery, a sealed lead storage battery, a nickel hydride battery, a lithium ion battery, a redox flow battery, or a NaS battery, an electric double layer capacitor, a fuel cell, etc. can be adopted. It is described.

JP 2005-57846 A

However, since the device described in Patent Document 1 requires a charge / discharge circuit for a storage battery, a circuit loss and a switching loss are generated by the circuit itself, and the power supply efficiency decreases due to this loss.
In addition, complicated charge / discharge control must be performed on the charge / discharge circuit.

  The present invention has been made in view of such circumstances, and an object thereof is to provide an elevator power supply apparatus that can suppress the maximum power received from a commercial power supply to a contract power or less without requiring a charge / discharge circuit. .

  The present invention is an elevator power supply device that converts AC power from a commercial power source and supplies it to a motor that raises and lowers a car, converts the AC power from the commercial power source into DC power, and outputs the DC power. A variable current rectifier having a variable current function, an inverter connected in parallel to the variable current rectifier on the output side of the variable current rectifier, and generating AC power supplied from the DC power to the motor; and the current An electric double layer capacitor that is directly connected in parallel with the variable rectifying means and the inverter, is charged with regenerative power during regenerative operation of the motor, and the charged power is discharged during power running operation of the motor; A control for detecting the direct current output from the variable current rectifier means and controlling the variable current rectifier means so that the power received from the commercial power supply does not exceed the contract power. Characterized in that it comprises a means.

  Unlike the storage battery, the electric double layer capacitor used in this device has its terminal voltage greatly fluctuated by charging and discharging, and becomes higher when charged and becomes lower when discharged. Therefore, when charged with regenerative power, in many cases, the voltage of the electric double layer capacitor rises higher than the voltage of the current variable rectifier. As a result, during the power running operation of the motor after the regenerative operation, first, energy is supplied from the electric double layer capacitor to the inverter, and the terminal voltage of the electric double layer capacitor begins to become lower than the voltage of the current variable rectifying means due to discharge. The variable rectifier is turned on (power can be supplied), and AC power from the commercial power supply is supplied to the inverter. On the other hand, during the regenerative operation of the motor, no current flows through the variable current rectifier, the electric double layer capacitor is charged, and the voltage rises. Thus, since the electric double layer capacitor of this device is directly connected to the inverter, charging and discharging are performed corresponding to the regenerative operation and power running operation of the motor, that is, the inverter. There is no need to provide a separate circuit and its control device.

Further, in the elevator power supply apparatus of the present invention, the control means detects the voltage of the electric double layer capacitor, and controls the variable current rectifying means when the voltage is smaller than a predetermined threshold, The electric double layer capacitor may be charged with the DC power output from the variable current rectifier.
As described above, in this device, the initial charging of the electric double layer capacitor and the charging when the voltage of the electric double layer capacitor falls below the threshold value can be executed by controlling the current variable rectifier. Thus, by ensuring the necessary minimum charge in the electric double layer capacitor, inrush current can be prevented from flowing into the electric double layer capacitor.

Further, in the present invention, the current variable rectifier means is a three-phase thyristor full-wave rectifier circuit, a three-phase mixed bridge rectifier circuit, a combination of a three-phase diode rectifier circuit and a step-down chopper circuit, or a three-phase diode. It can be constituted by a combination of a rectifier circuit and a step-up / down chopper circuit.
When the variable current rectifying means is configured by these circuits, the electric double layer capacitor can be initially charged while suppressing the received power exceeding the contract power.

In the present invention, the variable current rectifying means may be constituted by a high power factor converter.
When the variable current rectifying means is configured by a high power factor converter, it is possible to suppress received power exceeding contract power.

Since the elevator power supply apparatus of the present invention does not require a charge / discharge circuit, there is no circuit loss due to the charge / discharge circuit, and high charge / discharge efficiency is obtained. In addition, complicated charge / discharge control to the charge / discharge circuit is unnecessary, and the apparatus can be simplified.
In addition, the contract power can be kept low, and the electricity bill can be saved.

The figure which shows embodiment of the elevator power supply device of this invention Circuit diagram of elevator power supply device of embodiment 1 Circuit diagram of elevator power supply device according to embodiment 2 Circuit diagram of elevator power supply device according to embodiment 3 Circuit diagram of elevator power supply device according to embodiment 4 The figure which shows the conventional elevator power supply device

An embodiment of an elevator power supply device of the present invention will be described with reference to the drawings.
As shown in FIG. 1, this apparatus converts AC power from a commercial power source 10 into DC power, and also includes a current variable rectifying means 21 having a current variable function of DC power, and three DC power supplied from the DC to the AC motor 31. An inverter 22 that generates phase alternating current, an electric double layer capacitor (hereinafter referred to as EDLC) 23 directly connected in parallel between the inverter 22 that generates phase alternating current and the inverter 22, and variable current rectifier 21 includes a current sensor 25 that detects a direct current output from 21, a voltage sensor 26 that detects a voltage across terminals of the EDLC 23, and a control device 24 that controls the current variable rectifier 21.

The AC motor 31 rotates integrally with a sheave 32 around which a rope is wound. A cage 33 is suspended from one end of the rope, and a weight 34 is suspended from the other end.
The EDLC 23 is a capacitor using an electric double layer formed on the contact surface between the solid electrode and the electrolyte solution. Since the maximum voltage of one cell is about 2.5 V, for example, one capacitance is 200 F. These cells are used by connecting 170 cells in series. The EDLC 23 is charged with regenerative power during the regenerative operation of the motor 31, and the charged power is discharged during the power running operation of the motor 31. However, since the EDLC 23 has a large capacitance, it is very short. A large current can be charged and discharged over time.

  In addition, unlike the storage battery, the terminal voltage of the EDLC 23 fluctuates greatly due to charging / discharging, and increases when charged, and decreases when discharged. In this apparatus, as will be described later, charging / discharging of the EDLC 23 is controlled using this property of the EDLC 23. Since the EDLC 23 performs charge / discharge control by itself, it is not necessary to provide a separate charge / discharge control circuit.

The control device 24 receives the DC output current data of the current variable rectifier 21 detected by the current sensor 25 and the data of the voltage across the terminals of the EDLC 23 detected by the voltage sensor 26, and also the variable current rectifier. A DC current command that specifies the DC output current value of the means 21 and an EDLC minimum voltage command that specifies the minimum voltage of the EDLC 23 are input.
In the DC current command, the DC output current value of the variable current rectifying means 21 is specified so that the power received from the commercial power supply 10 does not exceed the contract power. In the EDLC minimum voltage command, the maximum voltage of the EDLC 23 that operates the variable current control means 21 is specified. That is, when the voltage of the EDLC 23 is equal to or lower than the minimum voltage command, the current variable control means 21 is operated to charge the EDLC 23, and when the voltage of the EDLC 23 is equal to or higher than the minimum voltage command, the operation of the current variable control means 21 is stopped. For example, in the case of a three-phase 200V power supply, about 250V, which is about 95% of 200V × 1.35, is designated as the lowest EDLC voltage. These commands are input in advance from an input operation unit (not shown) by an elevator administrator. The EDLC minimum voltage command is used as a command to end the initial charging of the EDLC 23 when the elevator is turned on. When the EDLC voltage drops below this voltage during power operation, the variable current control is performed. Used to drive the means 21.

The control device 24 controls the variable current rectifier 21 so that the direct current value of the variable current rectifier 21 detected by the current sensor 25 does not exceed the current value specified by the direct current command.
In addition, the control device 24 adjusts the current so that it does not exceed the contract power when the voltage between the terminals of the EDLC 23 detected by the voltage sensor 26 becomes equal to or lower than the EDLC minimum voltage specified by the EDLC minimum voltage command. While controlling the rectifying means 21, the alternating current from the commercial power supply 10 is converted into a direct current by the current variable rectifying means 21 and the EDLC 23 is charged.

Next, the operation of this apparatus will be described.
When the power is turned on, the control device 24 controls the variable current rectifying means 21 so as not to exceed the contract power for about 30 seconds after the power is turned on, while converting the alternating current from the commercial power supply 10 to the variable current rectification. The means 21 converts it into direct current, and the EDLC 23 is initially charged. When the voltage between the terminals of the EDLC 23 detected by the voltage sensor 26 reaches the EDLC minimum voltage, the rectification operation of the current variable rectifier 21 is stopped and the initial charging is finished.

For example, when more than half the number of passengers ride on the car 33 and rise, the motor 31 enters a regenerative operation state, and regenerative power is output from the inverter 22 to the EDLC. For this reason, the voltage on the input side of the inverter 22 (the side to which the EDLC 23 is connected) rises and in many cases becomes higher than the output terminal voltage of the current variable rectifying means 21, so that the current variable rectifying means 21 is turned off. Therefore, only the EDLC 23 is charged without the regenerative power flowing through the variable current rectifying means 21.
The charged voltage of the EDLC 23 is higher than the output terminal voltage of the variable current rectifier 21. Therefore, the off state of the variable current rectifier 21 continues while the EDLC 23 is in the charged state.

Next, when less than half the number of passengers get on the car 33 and descend, the motor 31 performs a power running operation. At this time, first, the EDLC 23 whose voltage has been increased is discharged, and the energy is supplied to the inverter 22 to generate an AC output to the motor 31. When the voltage of the EDLC 23 drops below the output terminal voltage of the variable current rectifying means 21 due to this discharge, the variable current rectifying means 21 is turned on, and this time, the alternating current from the commercial power supply 10 is changed by the variable current rectifying means 21. It is converted into a direct current and supplied to the inverter 22.
At this time, the control device 24 controls the variable current rectifier 21 so that the value of the direct current output from the variable current rectifier 21 does not exceed the current value specified by the direct current command.
Further, after the motor 31 is stopped, the control device 24 controls the current variable rectifying means 21 so that the contracted power is not exceeded until the terminal voltage of the EDLC 23 detected by the voltage sensor 26 reaches the EDLC minimum voltage. Meanwhile, the alternating current from the commercial power source 10 is converted into direct current by the variable current rectifying means 21 and the EDLC 23 is charged. When the voltage between the terminals of the EDLC 23 detected by the voltage sensor 26 reaches the EDLC minimum voltage, the rectification operation of the current variable rectifier 21 is stopped.

As described above, in this apparatus, the charge / discharge control of the EDLC 23 is automatically performed using the fact that the voltage of the EDLC 23 is changed by the charge / discharge. Therefore, the charge / discharge circuit 104 and the control device 106 as in Patent Document 1 are not required.
In addition, since the maximum power received from the commercial power source is suppressed by the control device 24 to be equal to or lower than the contract power, the contract power can be set low, and the electricity bill can be saved.
In the elevator power supply device of the present invention, when the commercial power supply fails, it is possible to move the operating car to the nearest floor or the reference floor using the stored energy of the EDLC 23, and at the time of a power failure using a storage battery. Automatic landing device can be omitted.

FIG. 2 shows a circuit diagram in the case where the variable current rectifying means 21 of this apparatus is configured by a three-phase thyristor full-wave rectifier circuit as the first embodiment.
The three-phase thyristor full-wave rectifier circuit 40 is composed of six thyristors. Further, the control device compares the inter-terminal voltage of the EDLC 23 with the lowest EDLC voltage, the direct current value output from the three-phase thyristor full-wave rectifier circuit 40, and the current value specified by the direct current command. Current controller 55 that specifies a current value based on the difference between them, a phase control angle calculator 54 that calculates a phase control angle for obtaining the specified current value, and a power supply phase detector that detects the phase of the power supply voltage And a gate drive circuit 53 that outputs a trigger signal to each thyristor of the three-phase thyristor full-wave rectifier circuit 40 when the phase of the power supply voltage matches the phase control angle.

The three-phase thyristor full-wave rectifier circuit 40 executes a rectification operation of a three-phase current input from a commercial power source based on a trigger signal input from the gate drive circuit 53. The DC current value output from the three-phase thyristor full-wave rectifier circuit 40 varies depending on the timing of the trigger signal.
The comparator 51 continues to output a signal to the gate drive circuit 53 when the voltage between the terminals of the EDLC 23 is lower than the EDLC minimum voltage, and the gate drive circuit 53 keeps the full wave of the three-phase thyristor until the signal from the comparator 51 stops. The trigger signal is continuously output to the rectifier circuit 40.
In this circuit, when the regenerative power exceeds the maximum chargeable voltage of the EDLC 23, a resistance chopper 27 is provided for consuming the excess as heat. This EDLC maximum voltage is about 400V, for example.
The three-phase thyristor full-wave rectifier circuit can be replaced with a three-phase mixed bridge rectifier circuit.

As a second embodiment, FIG. 3 shows a circuit diagram in the case where the variable current rectifying means 21 of this apparatus is constituted by a three-phase diode rectifier circuit and a step-down chopper circuit.
The step-down chopper circuit 42 includes a semiconductor switch, a diode, a smoothing reactor, and a smoothing capacitor, and reduces and outputs the current rectified by the three-phase diode rectifier circuit 41. The rate of current reduction is changed by changing the on / off timing of the semiconductor switch.

  The control device compares the voltage between the terminals of the EDLC with the lowest EDLC voltage, and the current based on the difference between the direct current value output from the step-down chopper circuit 42 and the current value specified by the direct current command. A current controller 55 that specifies a value and a gate drive circuit 53 that drives the semiconductor switch of the step-down chopper circuit 42 on and off. The gate drive circuit 53 is based on the current value specified by the current controller 55. The semiconductor switch ON / OFF timing is set, and the step-down chopper circuit 42 continues to be driven until the signal from the comparator 51 stops.

FIG. 4 shows a circuit diagram in the case where the variable current rectifying means 21 of this apparatus is constituted by a three-phase diode rectifier circuit and a step-up / step-down chopper circuit as a third embodiment.
In this circuit, the step-down chopper circuit portion of the circuit of FIG. 3 is changed to a step-up / step-down chopper circuit 43 capable of reducing and increasing a DC output current, but the other configurations are not changed.
In addition, since the step-up / step-down chopper circuit can boost the voltage, the value of the EDLC minimum voltage command can be selected to be higher than the output voltage of the three-phase diode rectifier circuit (200V x 1.35 = 270V for a three-phase 200V power supply). It is.

FIG. 5 shows a circuit diagram in the case where the variable current rectifying means 21 of this apparatus is configured by a high power factor converter as the fourth embodiment.
The high power factor converter 44 is a rectifier that shapes an input current waveform into a sine wave.
The control device includes a power supply phase detector 52 that detects the phase of the power supply voltage, a converter control circuit 56 that generates a switching signal of each switching element of the high power factor converter 44, and a gate drive circuit 53 that drives each switching element. Consists of. The converter control circuit 56 generates a switching signal for each switching element of the high power factor converter 44 based on the phase of the power supply voltage, the waveform of the power supply current, the power command, and the voltage between the terminals of the EDLC.
Since the high power factor converter 44 theoretically has a minimum output voltage, the DC output current can be suppressed below the contract power, but the initial charge of the EDLC cannot be performed. Therefore, it is necessary to perform initial charging with a separate dedicated circuit.

  The present invention can save the electric bill for the elevator with a simple configuration, and can be widely used in various elevators.

10 Commercial Power Supply 21 Variable Current Rectifier 22 Inverter 23 Electric Double Layer Capacitor (EDLC)
24 control device 25 current sensor 26 voltage sensor 27 resistance chopper 31 AC motor 32 sheave 33 car 34 weight 40 three-phase thyristor full-wave rectifier circuit 41 three-phase diode rectifier circuit 42 step-down chopper circuit 43 step-up / down chopper circuit 44 high power factor converter DESCRIPTION OF SYMBOLS 51 Comparator 52 Power supply phase detection part 53 Gate drive circuit 54 Phase control angle calculation part 55 Current controller 56 Converter control circuit 100 Commercial power supply 101 Rectifier 102 Smoothing capacitor 103 Inverter 104 Charging / discharging circuit 105 Storage battery 106 Control apparatus 110 AC motor 111 Class Car 112 basket 113 weight

Claims (7)

An elevator power supply device that converts AC power from a commercial power source and supplies it to a motor that raises and lowers a car,
AC power from a commercial power source is converted into DC power and output, and current variable rectifying means having a current variable function of the DC power;
An inverter connected in parallel to the current variable rectifier means on the output side of the current variable rectifier means, and generating AC power supplied from the DC power to the motor;
An electric double layer capacitor that is directly connected in parallel with the variable current rectifying means and the inverter and is charged with regenerative power during the regenerative operation of the motor, and the charged power is discharged during the power running operation of the motor When,
An elevator power supply comprising: a control means for detecting a direct current output from the current variable rectifier means and controlling the current variable rectifier means so that power received from a commercial power supply does not exceed contract power. apparatus.   2. The elevator power supply device according to claim 1, wherein the control unit detects a voltage of the electric double layer capacitor and controls the variable current rectifying unit when the voltage is smaller than a predetermined threshold value. 3. And the electric double layer capacitor is charged with the DC power output from the variable current rectifier.   3. The elevator power supply apparatus according to claim 1, wherein the variable current rectifying means is a three-phase thyristor full-wave rectifier circuit.   3. The elevator power supply apparatus according to claim 1, wherein the variable current rectifying means is a three-phase mixed bridge rectifier circuit. 4.   3. The elevator power supply apparatus according to claim 1 or 2, wherein the variable current rectifying means comprises a three-phase diode rectifier circuit and a step-down chopper circuit.   3. The elevator power supply apparatus according to claim 1, wherein the current variable rectification means includes a three-phase diode rectification circuit and a step-up / step-down chopper circuit.   2. The elevator power supply apparatus according to claim 1, wherein the variable current rectifying means comprises a high power factor converter.