JP2012218853A - Elevator control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elevator control device having a power storage device consisting of a plurality of cells, and capable of easily and reliably detecting the overvoltage of each cell.SOLUTION: A power storage device 15 is module-constituted by a plurality of cells, and provided with a voltage detector 20 for detecting the voltage of the entire voltage. Cell voltage detection circuits V1-Vn are provided, which detect any abnormality when any one of n-sets of cells, Se1-Sen is in an overcharged state, and output the cell overvoltage signal. The cell voltage detection circuits V1-Vn constantly monitor each overvoltage value Vco of the cells Se1-Sen, and the voltage detector 20 constantly monitors the overvoltage value Vmo (=n×Vco) of the entire module.

Description

  The present invention relates to an energy-saving elevator control device using a secondary battery.

  Conventionally, as an energy-saving type elevator control device that applies a secondary battery, low capacity and low cost by making the charge / discharge current to the power storage device variable by grasping the elevator operation status or the usage status of the power storage device An elevator control device using a simple power storage device is known (see, for example, Patent Document 1).

JP 2002-348057 A (summary column, FIG. 3)

  The elevator control device disclosed in Patent Document 1 accumulates DC power from a DC bus between a converter and an inverter during regenerative operation of the elevator and supplies the DC power stored during power running to the DC bus. The charge / discharge control means includes a storage device, charge / discharge control means for controlling charge / discharge of the power storage device with respect to the DC bus, and measurement means for measuring at least one of current / voltage of the power storage device. Is equipped with a current value limiting circuit that suppresses the charge / discharge current command value within the limit value according to the output from the measuring means, and this current value limit circuit operates the elevator based on the calculation result of the charge / discharge integrated amount. It is determined whether the state is a power-running self-running state or a regenerative self-running state, and a charge / discharge current limit value is set according to the determination result.

  According to the elevator control device disclosed in Patent Document 1, an inexpensive power storage device with a small capacity can be obtained by making the charge / discharge current variable by grasping the operating state of the elevator or the utilization status of the power storage device. Even if is used, it is possible to provide an elevator control device having a high energy saving effect without reducing the energy saving effect and using a power storage device having a long battery life.

  By the way, although there are various devices in the power storage device, it is possible to store larger regenerative power by using a plurality of power storage devices according to the scale of the elevator system. When the power storage device is composed of a plurality of cells, it is necessary to detect the overvoltage of each cell or the variation between the cells. However, in the elevator control device disclosed in Patent Document 1, the overvoltage of the cell or the cell There is no disclosure of detecting a variation in between.

  For example, in the case of a power storage device such as an electric double layer capacitor in which overvoltage is dangerous, it has been difficult to adopt in a system installed in a building such as an elevator. However, by making the system that can reliably detect the overvoltage of the cells that make up the power storage device, it can be applied to an elevator system, and the elevator system can be configured to make the most of the power storage device. Become.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an elevator control device in which a power storage device is configured from a plurality of cells, and an overvoltage of the cells can be easily and reliably detected. Is.

  The elevator control device according to the present invention drives a motor by converting a DC power from the converter into a DC power by rectifying AC power and driving the motor by converting the DC power from the converter into AC power having a variable voltage and a variable frequency. Provided between the inverter and a DC bus between the converter and the inverter, accumulates DC power from the DC bus during regenerative operation of the elevator, and stores DC power accumulated during power running to the DC bus In the elevator control device comprising the power storage device to be supplied, the power storage device is constituted by a plurality of cells, and voltage detecting means for detecting a voltage in which the plurality of cells of the power storage device are combined, and the cell Cell voltage detecting means for detecting the respective cell voltages.

  According to the elevator control device according to the present invention, it is possible to detect that one of the plurality of cells constituting the power storage device is in an overcharged state, so that the cell of the power storage device is overcharged. It becomes possible to grasp the state of the power storage device before taking the state and take measures. In addition, it is possible to detect cell-to-cell variation, so that it can be used within a safe range by limiting the rated capacity even after overcharge detection without continuing to use the battery while the power storage device is unbalanced. Measures can be taken. Therefore, the elevator system can be configured to make the best use of the power storage device.

1 is a system configuration diagram showing an elevator control apparatus according to Embodiment 1 of the present invention. It is a figure which shows the electric power storage apparatus used for the elevator control apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a flowchart for detecting an abnormal state of the power storage device shown in FIG. 2. It is a figure explaining cancellation of the abnormal state of the power storage device shown in FIG.

  Preferred embodiments of an elevator control device according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and includes various design changes.

Embodiment 1 FIG.
FIG. 1 is a system configuration diagram showing an elevator control apparatus according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a general commercial power source such as a three-phase alternating current. Reference numeral 2 denotes an electric motor such as a three-phase AC electric motor. By rotating the hoisting machine 3 with the electric motor 2, the elevator car 5 and the counterweight 6 connected to both ends of the rope 4 are moved up and down. Carry passengers in the car to the designated floor.

  The AC power supplied from the commercial power source 1 is rectified and converted into DC power via a converter 8 including a switch 7 and a diode, and the converted DC power is stored in the capacitor 9 and also DC. Supplied to the bus 10. The DC power is converted into AC power having a variable voltage and variable frequency via an inverter 11 composed of a transistor, an IGBT, or the like.

  The elevator control panel 12 is composed of a microcomputer or the like, and manages and controls the entire elevator. The elevator control panel 12 creates an elevator position / speed command as well as an elevator start / stop command. Further, the elevator control panel 12 determines the position of the elevator created based on the information of the current feedback from the current detection device 13 and the speed feedback from the speed detection device 14 including an encoder mounted on the hoisting machine 3. Based on the speed command, the electric motor 2 is rotationally driven to realize the position / speed control of the elevator.

  The balance weight 6 of the elevator is set to a weight that balances when an appropriate load (usually half of the rated load) is on the car 5. Therefore, in general, when raising and lowering the car 5 with no load, when the car 5 is lowered, power running operation is performed while consuming electric power, and when it is raised, regenerative operation is performed to return speed energy to electric power. Conversely, when the vehicle is lowered at the rated load, the regenerative operation is performed, and when the vehicle is lifted, the power running operation is performed.

  The elevator control device according to the first embodiment includes a power storage device 15 configured as a secondary battery in modules, a charging / discharging device 16 including a DC-DC converter, and the charging / discharging device 16 charging. A charge / discharge control device 17 that controls the discharge power, and the regenerative power during the regenerative operation is stored in the power storage device 15 via the switch 18 and the charge / discharge device 16. The charge / discharge control device 17 includes a current value limiting device 19 that suppresses the charge / discharge current command value within a limit value in accordance with a command from the elevator control panel 12, and controls the charge / discharge power of the charge / discharge device 16. It is configured as follows.

  As described above, the elevator control apparatus according to the first embodiment accumulates DC power from the DC bus 10 between the converter 8 and the inverter 11 during the regenerative operation of the elevator, and stores the DC power accumulated during the power running operation. A power storage device 15 that supplies power to the DC bus 10 and a charge / discharge control device 17 that controls charging / discharging of the power storage device 15 with respect to the DC bus 10 are provided. The charge / discharge control device 17 responds to a command from the elevator control panel 12. A current value limiting device 19 that suppresses the charge / discharge current command value within the limit value is provided. In addition, the power storage device 15 is configured in a module configuration with a plurality of cells in order to reuse the regenerative power and save energy by sufficiently receiving the regenerative power generated during the regenerative operation generated in the elevator system. .

  By the way, when the power storage device 15 is configured as a module with a plurality of cells, it is necessary to pay attention to safety circuit design. In the voltage measurement in the entire power storage device 15, variation occurs in a plurality of constituting cells, and even if any of the cells is in an overvoltage state, it cannot be detected. Depending on the type of the power storage device 15, in particular, in an electric double layer capacitor, overcharging may cause a risk of destruction of the capacitor, leakage, smoke generation, or the like.

  Therefore, the power storage device 15 is provided with voltage detection means for detecting the voltage of the entire capacitor module, and the capacitor module includes at least one of the constituent cells (the number of constituent cells is n hereinafter). Cell voltage detection means for detecting that one is overcharged is provided.

  FIG. 2 is a diagram showing the power storage device 15, in which voltage detection means 20 for detecting the voltage of the entire capacitor module is provided, and when any of the n cells Se1 to Sen is overcharged, an abnormality is detected. Cell voltage detection circuits V1 to Vn are provided as cell voltage detection means for outputting a cell overvoltage signal. Then, the cell voltage detection circuits V1 to Vn constantly monitor the overvoltage values Vco of the cells Se1 to Sen, and the voltage detection means 20 constantly monitors the overvoltage value Vmo (= n × Vco) of the entire module.

  Depending on the type of power storage device 15 and the system configuration, when the overvoltage signal detection of the cells Se1 to Sen is performed, the module voltage value Vm and the cell overvoltage signal output are constantly monitored. In order to detect variations in the cells Se1 to Sen, it is possible to constantly monitor or detect that the elevator operation is stopped, that is, that the power storage device 15 is not charged / discharged. As shown in the flowchart, a test mode related to variation is provided, and the power storage device 15 is charged with a constant current. When the cell overvoltage signal is detected before the module voltage value Vm reaches the module overvoltage value Vmo, it is easy that a certain cell voltage in the module is high, that is, a voltage variation between cells occurs. Can be detected. Further, when the module voltage at the moment when the cell overvoltage signal is detected is lower than the overvoltage value Vmo, it can be seen that certain cells Se1 to Sen in the module are overcharged. It is possible to check the soundness of the power storage device 15 by periodically checking in the test mode whether the cells in the module of the power storage device 15 are uneven.

  When overcharging of the cells Se1 to Sen is detected, the charging is stopped, and as shown in FIG. 4A, the balance circuits B1 to Bn-1 such as resistors are connected between the cells Se1 to Sen and balanced. . FIG. 4B is a detailed diagram of the balance circuit Bn, which is composed of a series body of a resistor R and a transistor Tr. The current to the resistor R is controlled by the control of the transistor Tr, and the voltage between the cells Se1 to Sen is in a balanced state. It becomes.

  For example, in FIG. 4A, when the voltage of the leftmost cell Se1 is high, the balance circuit B1 operates to discharge and balance the charge of the cell Se1. However, this operation requires an operation for discharging electric charges, and requires time for the operation. In an elevator system, the time until the variation of the cells Se1 to Sen is eliminated in a frequently used state, and stopping charging / discharging for the occurrence of variation reduces the energy saving effect. Limited to a limited range for 15 capacities. Next, this restriction method will be described.

  For example, when the power storage device 15 is configured by an electric double layer capacitor, the voltage and the capacity are in a substantially proportional relationship, so that the power storage device 15 can be charged up to the rated rated total voltage Vmt and is normally used. For example, when checking for variation in the test mode, in the cell overvoltage signal, the module voltage Vma (Vma <Vmt) when the signal is output until the operation for eliminating variation after the check is performed. In the elevator system, the charge / discharge range to the power storage device 15 is controlled up to the module voltage Vma.

  Since charging is controlled so that it stops at the module voltage Vma, charging / discharging control for the power storage device 15 is not stopped even when variations occur, and it is used in a safe range, so it is more than normal. Although it is inferior, the energy saving effect is not lost.

  The power storage device 15 has a capacity variation due to deterioration over time. For example, an electric double layer capacitor has a high internal resistance value due to aging, but the resistance value varies depending on the cells Se1 to Sen. Further, the voltage of the capacitor also increases due to the increase of the internal resistance value. Therefore, using a circuit similar to the above-described variation check, a test mode in which constant current charging is performed periodically is performed, and charging is performed up to the rated operating total voltage Vmt. When a cell overvoltage signal is detected before reaching the rated rated total voltage Vmt, the capacity variation between the cells Se1 to Sen occurs, so that the rated capacity of the power storage device 15 is limited as described above.

  As for the method of limiting the rated capacity of the power storage device 15, if the capacity is limited by the module voltage Vma when the signal is output, the variation signal is output again when the module voltage becomes Vma until the variation reset operation. Therefore, for example, when Vma × a (0 <a <1) is reached, control is performed to stop charging and discharging.

  As described above, according to the elevator control device according to the first embodiment, when any one of the plurality of cells Se1 to Sen is overcharged in the power storage device 15 including the plurality of cells Se1 to Sen. A system capable of detecting overcharge of cells Se1 to Sen and variations between cells Se1 to Sen by detecting an abnormality and comparing the total voltage of the power storage device 15 with a circuit that outputs a cell overvoltage signal is configured. Can do. Therefore, the elevator system can be configured to make the best use of the power storage device.

  Further, since any one of the plurality of cells Se1 to Sen is equipped with cell voltage detection circuits V1 to Vn for detecting an abnormality and outputting a cell overvoltage signal when overcharge occurs, the outputs of the circuits V1 to Vn are provided. By looking at the signal to be detected, it is possible to reliably detect when an overvoltage abnormal state of the power storage device 15 occurs. When one of the plurality of cells Se1 to Sen is in an overvoltage state, a signal is output from the cell voltage detection circuits V1 to Vn. It can be seen that Sen is not in an overvoltage condition and the system can be kept in a safe state.

  Moreover, it is possible to ensure the safety of the power storage device 15 quickly by always detecting the overvoltage of the cells Se1 to Sen or the variation between cells. In addition, the power storage device 15 incorporated in the system charges and discharges in synchronization with the movement of the elevator, but depending on characteristics such as the internal resistance of the power storage device 15, voltage fluctuation occurs during charging and discharging. Therefore, by checking the cell overvoltage signal while the operation of the elevator is stopped, it is possible to determine whether the overvoltage of the cells Se1 to Sen or the variation between the cells has occurred from the state where the fluctuation due to the elevator state is small. Is possible.

  In addition, when signals from the cell voltage detection circuits V1 to Vn that output overvoltage signals of the cells Se1 to Sen are detected, the power storage device 15 can be safely used by limiting the capacity range used by the power storage device 15 The power storage device 15 can be used as much as possible as an elevator system.

DESCRIPTION OF SYMBOLS 1 Commercial power supply 2 Electric motor 3 Hoisting machine 4 Rope 5 Car 6 Balance weight 7, 18 Switch 8 Converter 9 Capacitor 10 DC bus 11 Inverter 12 Elevator control panel 13 Current detection device 14 Speed detection device 15 Power storage device 16 Charging / discharging device 17 Charge / Discharge Control Device 19 Current Value Limiting Device 20 Voltage Detection Means Se1 to Sen Cell V1 to Vn Cell Voltage Detection Circuit B1 to Bn-1 Balance Circuit

Claims (5)

A converter that rectifies AC power and converts it into DC power, an inverter that drives an electric motor by converting DC power from the converter into AC power of variable voltage and variable frequency, and operates an elevator; the converter and the inverter; A power storage device that is provided between the DC buses between the DC buses, stores DC power from the DC buses during regenerative operation of the elevator, and supplies DC power stored during powering operation to the DC buses. In the elevator control device,
The power storage device includes:
A voltage detection unit configured to detect a voltage including a plurality of cells of the power storage device and a cell voltage detection unit configured to detect a cell voltage of each of the cells. Elevator control device.   The cell voltage detection means is configured by a device that detects an abnormality when at least one of cells constituting the power storage device is overcharged and outputs a cell overvoltage signal. Elevator control device.   3. The elevator control device according to claim 1, wherein the detection of the overvoltage of the cell or the variation between cells is always performed regardless of the movement of the elevator.   3. The elevator control device according to claim 1, wherein the detection of the overvoltage of the cell or the inter-cell variation is performed periodically or during an elevator operation stop.   A charge / discharge control device for controlling charging / discharging of the power storage device with respect to the DC bus, and limiting the capacity used by the power storage device by the charge / discharge control device when an overvoltage of the cell or a variation between cells is detected; And the electric power of the said elevator is charged / discharged, The elevator control apparatus as described in any one of Claims 1-4 characterized by the above-mentioned.

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