Elevator control device

Abstract

It is an object to reduce the burden on an operator during rescue operation. An elevator control device according to an embodiment is a device that controls a power supply from an inverter, which supplies power to a hoisting motor that drives an elevator car, to said hoisting motor. The elevator control device has a power supply control device and a speed adjustment device. The power supply control device comprises an arc control unit for controlling an output power of the inverter by adjusting a pulse width of a PWM signal that turns switching elements constituting the inverter on and off, and a brake control unit that controls a brake for restraining the hoisting motor. The speed adjustment device adjusts a hoisting speed during rescue operation of the car by alternately providing an on-period, during which the PWM signal output by the arc control unit is allowed to be output, and an off-period, during which the arc control unit stops outputting the PWM signal.

Description

ELEVATOR CONTROL DEVICE BACKGROUND 1. Technical Field

[0001] The embodiments of the present invention relate to an elevator control device. 2. Related Art

[0002] An elevator is designed to perform an emergency stop for safety reasons when a major earthquake occurs. When the elevator performs an emergency stop, a rescue operation is initiated to move a car to the nearest floor.

[0003] During rescue operation, a brake is manually released to move the car up or down. At this time, with safety in mind, manual operation is performed to limit the car hoisting speed intermittently applying the brake.

[0004] When the brake is released, the car falls rapidly due to its own weight. Accordingly, since subtle control is required to limit the hoisting speed, an operator must exercise extreme caution. In addition, because the brake is operated manually, there is also the problem of increased car vibration during rescue operation. Prior Art Document Patent Document

[0005] Patent Document 1: JP 2008-56428 A

[0006] The present invention has been made under the above-described circumstances, HK 20137914 A 1 and aims to reduce burden on operators during rescue operation. SUMMARY

[0007] An elevator control device according to an embodiment for solving the above problem is a device that controls a power supply from an inverter, which supplies power to a hoisting motor that drives an elevator car, to said hoisting motor. The elevator control device has a power supply control device and a speed adjustment device. The power supply control device comprises an arc control unit for controlling an output power of the inverter by adjusting a pulse width of a PWM signal that turns switching elements constituting the inverter on and off, and a brake control unit that controls a brake for restraining the hoisting motor. The speed adjustment device adjusts a hoisting speed during rescue operation of the car by alternately providing an on-period, during which the PWM signal output by the arc control unit is allowed to be output, and an off-period, during which the arc control unit stops outputting the PWM signal. BRIEF DESCRIPTION OF DRAWINGS

[0008] Fig. 1 is a block diagram of an elevator control device according to a first embodiment. Fig. 2 is a diagram illustrating a speed control pattern generated by the elevator control device according to the first embodiment. Fig. 3 is a diagram illustrating the speed control pattern generated by the elevator control device according to the first embodiment. Fig. 4 is a diagram illustrating the speed control pattern generated by the elevator control device according to the first embodiment. HK 20137914 A 2 Fig. 5 is a diagram illustrating the speed control pattern generated by the elevator control device according to the first embodiment. Fig. 6 is a flowchart illustrating an operation of the elevator control device according to the first embodiment. Fig. 7 is a diagram illustrating the operation of the elevator control device according to the first embodiment. Fig. 8 is a diagram illustrating a control pattern generated by an elevator control device according to a second embodiment. Fig. 9 is a block diagram of an elevator control device according to a fourth embodiment. DETAILED DESCRIPTION

[0009] The present embodiment will be described below with reference to drawings. The diagrams and flowcharts used to describe the present embodiment are illustrative examples.

[0010] FIRST EMBODIMENT Figure 1 is a block diagram of an elevator control device 100 according to the present embodiment. The elevator control device 100 is a device that controls supply of power from an inverter 12, which constitutes a power supply device 10 that supplies power to a hoisting motor 20 for driving an elevator car up and down, to the hoisting motor 20.

[0011] The hoisting motor 20 is a motor for driving the car up and down. The hoisting motor 20 is equipped with a drum brake 31 and a dynamic brake 32. The drum brake HK 20137914 A 3 31 is a brake that stops a rotation of the hoisting motor 20 by pressing a brake drum against a rotational shaft of the hoisting motor 20. The dynamic brake 32 is a brake that stops the rotation of the hoisting motor 20 by interrupting a current supplied to the hoisting motor 20. The dynamic brake 32 is, for example, composed of a relay.

[0012] The power supply device 10 is configured to include a converter 11 and the inverter 12. The converter 11 converts commercial AC voltage into a predetermined DC voltage. The inverter 12 converts the DC voltage into a three-phase AC voltage suitable for the hoisting motor 20. Under normal conditions, the power supply device 10 operates by receiving power from a commercial power source 1. In case of power outage, the power supply device 10 operates by receiving power from a battery 2.

[0013] The inverter 12 is composed of a plurality of switching elements and outputs the three-phase AC voltage by turning the plurality of switching elements on and off. A gate control signal for turning the switching elements on and off is supplied from a power supply control device 40.

[0014] The power supply control device 40 has an arc control unit 41, a brake control unit 42, and an abnormality detection unit 43. The arc control unit 41 generates the gate control signal (PWM signal) that turns the switching elements constituting the inverter 12 on and off. The gate control signal is formed, for example, as a continuous pulse signal (PWM signal) ranging from several kHz to several tens of kHz. The arc control unit 41 controls an output power of the inverter 12 by adjusting a pulse width of the PWM signal. In addition, when the arc control unit 41 receives a notification from the abnormality detection unit 43 that an abnormality has been detected, the arc control unit 41 stops the inverter 12 by setting the pulse width of the gate control signal to “0”. HK 20137914 A 4

[0015] The abnormality detection unit 43 has a temperature measurement unit 431 that detects temperature abnormalities in the inverter 12. A temperature sensor is disposed near the switching elements of the inverter 12, and the temperature measurement unit 431 detects, for example, when the temperature of the inverter 12 reaches or exceeds a threshold temperature indicating an over-temperature condition. In addition, the abnormality detection unit 43 has a speed measurement unit 432 that detects abnormalities in a rotational speed of the hoisting motor 20. The speed measurement unit 432 detects, for example, when the rotational speed of the hoisting motor 20 reaches or exceeds a threshold rotational speed indicating an over-temperature condition. The abnormality detection unit 43 notifies the arc control unit 41 and the brake control unit 42 that an abnormality has been detected.

[0016] The brake control unit 42 controls the drum brake 31. When the brake control unit 42 outputs a drum brake release signal, the drum brake 31 restrains the rotation of the motor shaft of the hoisting motor 20, causing the rotation shaft to decelerate and come to a stop.

[0017] In addition, the elevator control device 100 is equipped with a speed adjustment device 50. When the car makes an emergency stop due to an earthquake, power outage, or other cause, a rescue operation is performed. If the car makes an emergency stop, it is desirable to return a normal operation after conducting a safety inspection. However, since it may take a long time to complete the safety inspection, there is a risk that passengers will be trapped inside the car for an extended period. To prevent this, the rescue operation is performed. Since the rescue operation is performed before the safety inspection is completed, operating the car at normal hoisting speed involves a HK 20137914 A 5 significant risk. The speed adjustment device 50 is a device for adjusting the hoisting speed during rescue operation of the car.

[0018] The speed adjustment device 50 adjusts the hoisting speed during rescue operation of the car by alternately providing an "on" period, during which the PWM signal output by the arc control unit 41 is allowed to be output, and an "off" period, during which the arc control unit 41 stops outputting the PWM signal. The speed adjustment device 50 has a memory unit 51, an extraction unit 52, a car position detection unit 53, a load weight detection unit 54, a control signal generation unit 55, a brake release command reception unit 61, a power failure detection unit 62, and an earthquake detection unit 63.

[0019] The memory unit 51 stores information on multiple speed control patterns that derive changes in the car hoisting speed corresponding to combinations of travel distance from a stopping position of the car to the nearest floor's stopping position and load weight of the car. The method for generating the speed control patterns will be described below.

[0020] The car position detection unit 53 calculates the travel distance from the position of the stopped car to the stopping position of the nearest floor. Information on the car stopping position can be obtained, for example, from a distance sensor provided at the bottom of the car that measures the distance between the car and the floor, or by calculating the current car position based on value of a pulse generator provided on the hoisting motor 20. Since the positions of each floor are known, the travel distance during rescue operation can be calculated based on the information from the distance sensor. HK 20137914 A 6

[0021] The load weight detection unit 54 obtains load weight information, for example, from a weight sensor provided at the bottom of the car.

[0022] The extraction unit 52 extracts information on the corresponding speed control pattern from the memory unit 51 based on information on the travel distance from the position of the stopped car to the nearest floor’s stop position and on the car load weight.

[0023] The control signal generation unit 55 generates a control signal that controls the inverter 12 via the arc control unit 41 based on the extracted speed control pattern information when the control signal generation unit 55 receives an instruction for rescue operation from the brake release command reception unit 61, the power failure detection unit 62, or the earthquake detection unit 63. In addition, the control signal generation unit 55 outputs the drum brake release signal to release the drum brake 31.

[0024] The brake release command reception unit 61 is a function that accepts manual operation by an operator or remote operation from a remote control device 200. The brake release command reception unit 61 has wireless or wired communication capabilities and can accept commands from the operator via the remote control device 200 to execute the rescue operation of the elevator control device. The brake release command reception unit 61 sends the instruction for starting rescue operation to the control signal generation unit 55.

[0025] The power failure detection unit 62 detects when a power failure has occurred. The power failure detection unit 62 detects whether the power failure has occurred by, for example, monitoring current supplied from the commercial power source 1. When HK 20137914 A 7 the power failure detection unit 62 detects the power failure, the power failure detection unit 62 switches from the commercial power source 1 to the battery 2 and sends the instruction for starting rescue operation to the control signal generation unit 55.

[0026] The earthquake detection unit 63 is a device that detects the occurrence of an earthquake. When the earthquake detection unit 63 detects a major earthquake (e.g., a predetermined seismic intensity, magnitude, acceleration, or displacement), the earthquake detection unit 63 causes the elevator to make an emergency stop and, after the earthquake has subsided, sends the instruction for starting rescue operation to the control signal generation unit 55.

[0027] (EXPLANATION OF CAR OPERATION DURING RESCUE OPERATION) Figure 2 shows an example of the car hoisting speed during rescue operation. Time T0 represents a start of rescue operation. The speed increases from time T0 to time T1, reaching a set speed during rescue operation at time T1. The set speed is set to a value lower than a maximum limitation speed. For example, the set speed during rescue operation is set to approximately 10% of the set speed during normal operation. From time T1 to time T2, the car moves up or down at the set speed. From time T2 to time T3, the speed is reduced, and at time T3, the car is stopped at the nearest floor’s stopping position. The area enclosed by a graph showing the car speed transition from time T1 to time T3 represents the car travel distance (which is a distance that the car travels from its position at the time of an emergency stop to the nearest floor’s stopping position).

[0028] If the distance from the car position at the time of an emergency stop to the nearest floor is short, there are cases where the car arrives at the nearest floor before HK 20137914 A 8 reaching the set speed for rescue operation. The graph showing the car speed transition in such a case is as shown in Figure 3.

[0029] (REGARDING METHOD FOR GENERATING SPEED CONTROL PATTERN) The speed adjustment device 50 controls the arc control unit 41 of the power supply control device 40 based on the speed control pattern shown in Figure 4(b) so that the car hoisting speed follows the speed transition shown in Figure 4(a). The speed adjustment device 50 controls the arc control unit 41 so that the arc control unit 41 supplies the gate control signal (PWM signal) to the inverter 12 during a high-level period shown in Figure 4(b). In addition, during a low-level period, the arc control unit 41 is controlled to turn off the switching elements of the inverter 12. For example, the pulse width of the gate control signal (PWM signal) supplied to the inverter 12 is set to “0”. The speed control pattern shown in Figure 4(b) is stored in the memory unit 51. Next, the method for generating the speed control pattern will be explained.

[0030] A speed variation pattern shown in Figure 4(b) is generated based on the car speed transition pattern shown in Figure 4(a). The speed control pattern is configured such that the time width of the on-period gradually increases until the car hoisting speed reaches a specified speed; once the car hoisting speed reaches the specified speed, the time width of the on-period becomes constant; and when the car hoisting speed decreases, the time width of the on-period gradually decreases.

[0031] Referring to Figure 5, the method for generating the speed control pattern from time T0 to time T1 will be explained. In Figure 5, a high-level period is denoted as Ton, and a low-level period is denoted as Toff. From time T0 to time T1, the time width of the high-level period (the time width of Ton) is gradually increased. In this case, HK 20137914 A 9 the time width of the low-level period (the time width of Toff) is kept constant. From time T1 to time T2, the high-level time width (the time width of Ton) is kept constant. From time T2 to time T3, the high-level time width (the time width of Ton) is gradually narrowed.

[0032] By establishing a low-level interval and adjusting a low-level time width, in details, by adjusting a ratio of the high-level time width to the low-level time width and a change of the ratio, it is possible to control an acceleration of the car during the car hoisting movement. In addition, by gradually widening the high-level time width, the acceleration at the start of the rescue operation can be reduced compared to when the high-level time width is kept constant. The lower the acceleration, the more car vibration can be reduced.

[0033] The degree of increase in the high-level time width and the low-level time width are determined by taking into account the travel time during rescue operation. For example, the travel time for the maximum travelling distance (e.g., 10 m) during rescue operation is set to 60 seconds or less, and the time interval from time T0 to time T1 is set to 10 seconds, the low-level time width (the time width of Toff) is set to 3 seconds or more. Although the trend of the high-level time width (the time width of Ton) can be estimated based on design values, it is ultimately set based on experiments. In this case, in order to limit acceleration, the maximum value of the high-level time width is set to, for example, 3 seconds or less. Note that the maximum value of the high-level time width may be set to 1 second or less, or 5 seconds or less.

[0034] From time T1 to time T2, the high-level time width is set so that the set speed can be maintained. The low-level time width may be the same as that for the interval HK 20137914 A 10 between time T0 and time T1. For the interval from time T2 to time T3, the settings should be the reverse of those for the interval between time T0 and time T1.

[0035] The trapezoidal shape shown in Figure 4(a) varies depending on the travel distance of the car during rescue operation. For example, assuming a maximum travel distance of 10 m, a graph as shown in Figure 4(a) is created for every 10 cm of travel distance, and 100 types (1000 cm ÷ 10 cm) of speed control patterns as shown in Figure 4(b) are created.

[0036] In addition, since the power required by the hoisting motor 20 varies depending on the load weight of the car, it is necessary to adjust the speed control patterns shown in Figure 4(b). For example, in case that the load weight is set from 0 to 500 kg, 10 types of speed control patterns (500 kg ÷ 50 kg) are created for every 50 kg. In other words, in case that there are 100 types of travel distance patterns, 1000 types of speed control patterns are created.

[0037] These speed control patterns are ultimately finalized based on experiments. In addition, since the speed control patterns must be adjusted according to factors such as the weight of the car and friction with guardrails, it is desirable to set the speed control patterns for each elevator model. The speed control patterns are stored in memory unit 51 with the travel distance and load weight conditions added as flags.

[0038] (OPERATION DESCRIPTION) Next, referring to Figure 6, the operation of the elevator control device 100 will be explained. When the elevator makes an emergency stop and receives a rescue operation instruction from the brake release command reception unit 61, the power HK 20137914 A 11 failure detection unit 62, or the earthquake detection unit 63, the rescue operation is initiated.

[0039] When the rescue operation begins, the speed adjustment device 50 acquires information on the car position and the load weight (Step S11). The speed adjustment device 50 calculates the travel distance to the nearest floor based on the car position information (Step S12).

[0040] Next, the speed control device 50 selects the speed control pattern with conditions closest to the acquired travel distance and load weight from among the multiple speed control patterns stored in the memory unit 51 (Step S13). Since the multiple speed control patterns stored in the memory unit 51 are tagged with flags indicating travel distance and load weight, the extraction unit 52 selects the corresponding speed control pattern by comparing these flag conditions with the acquired conditions.

[0041] During rescue operation, the drum brake 31 is released. The control signal generation unit 55 of the speed adjustment device 50 generates the drum brake release signal as shown in Fig. 4(c) in accordance with the time width of the selected speed control pattern (the time width from time T0 to time T3). Then, the speed adjustment device 50 releases the drum brake 31 via the brake control unit 42 using the drum brake release signal as shown in Fig. 4(c) (Step S14).

[0042] Once the speed control pattern is determined, the speed adjustment device 50 controls the inverter 12 via the arc control unit 41 of the power supply control device 40 (Step S15). Figure 7(a) shows a schematic diagram of the gate control signal supplied HK 20137914 A 12 by the arc control unit 41 to the inverter 12 before receiving control from the speed adjustment device 50. The gate control signal supplied by the arc control unit 41 to the inverter 12 before receiving control from the speed adjustment device 50 is a continuous PWM signal. During normal operation, the speed adjustment device 50 supplies a high-level signal to the arc control unit 41, and the arc control unit 41 supplies the gate control signal as shown in Figure 7(a) directly to the inverter 12.

[0043] Figure 7(b) shows an example of a speed control pattern. The high-level period (period of Ton) is the period during which the arc control unit 41 is permitted to output a PWM signal, while the low-level period (period of Toff) is the period during which the arc control unit 41 stops outputting a PWM signal. Figure 7(c) shows the gate control signal supplied by the arc control unit 41 to the inverter 12 after receiving control from the speed adjustment device 50. The car will move up and down based on the speed control pattern generated by the speed adjustment device 50.

[0044] Even during rescue operation, the abnormality detection unit 43 of the power supply control device 40 performs temperature checks on the inverter 12 and checks the hoisting speed of the car (Step S16). If an abnormality is detected in the temperature of the inverter 12 (Step S17: Yes), the power supply control device 40 controls the inverter 12 to stop via the arc control unit 41 (Step S18). In addition, if an abnormality is detected in the car hoisting speed (Step S17: Yes), the power supply control device 40 stops the release of the drum brake via the brake control unit 42 (Step S18).

[0045] If the abnormality detection unit 43 does not detect an abnormality (Step S17: No), the drum brake 31 remains released, and the rescue operation continues (Step S19). Then, the rescue operation ends when the car arrives at the nearest rescue floor. HK 20137914 A 13

[0046] As described above, the elevator control device 100 according to the first embodiment controls the rescue operation, which adjusts the hoisting speed of the car during rescue operation, by alternately providing an on-period during which the arc control unit 41 is permitted to output a PWM signal and an off-period during which the arc control unit 41 stops outputting the PWM signal. In other words, during rescue operation, the operator does not need to manually perform braking operations that require excessive attention. As a result, the elevator control device can reduce the operator’s workload during rescue operation.

[0047] In addition, since the elevator control device 100 controls the arc control unit 41 by selecting a speed control pattern based on the travel distance and the load weight of the car during rescue operation, it is possible to perform control during rescue operation according to the emergency stopping position and load weight of the car.

[0048] In addition, the elevator control device 100 adjusts the hoisting speed and acceleration of the car during rescue operation by alternately establishing an on-period, during which the arc control unit 41 is permitted to output a PWM signal, and an off- period, during which the arc control unit 41 stops outputting the PWM signal, and therefore, it is possible to further suppress car vibration (swaying and rattling of the car) during rescue operation.

[0049] Furthermore, the elevator control device 100 configures the speed control pattern such that the time width of the on-period gradually increases until the car hoisting speed reaches a predetermined speed, and once the car hoisting speed reaches the predetermined speed, the time width of the on-period becomes constant, and when HK 20137914 A 14 the car hoisting speed decreases, the time width of the on-period gradually decreases. By configuring the speed control pattern in this manner, the elevator control device 100 can further suppress car vibration (swaying and rattling of the car) during rescue operation.

[0050] SECOND EMBODIMENT In the first embodiment, as shown in Figure 4(b), the case in which the time width of the high level of the speed control pattern (the time width of Ton) is gradually varied was described. As a simplified embodiment, as shown in Figure 8(b), the time width of the high level of the speed control pattern (the time width of Ton) may also be kept constant. Compared to the first embodiment, the acceleration at the start of rescue operation becomes larger, so the car vibration also becomes slightly larger. However, the acceleration can be adjusted by reducing the ratio of the low-level time width to the high-level time width (Ton / Toff). In this case, if one attempts to shorten the arrival time at the nearest floor, it is necessary to increase the value of (Ton / Toff), and it is anticipated that the acceleration (car vibration) will increase accordingly. Therefore, it is important to maintain balance car vibration and travel time.

[0051] THIRD EMBODIMENT The first embodiment explained the case in which the speed control pattern is changed in response to the car load weight. As another embodiment, a configuration that does not consider the car load weight as a parameter is conceivable. For example, in a passenger elevator carrying only a few passengers, the ratio of passenger weight to car weight is small. For instance, the change in car weight between having one passenger and five passengers is minimal. In addition, in the case of freight elevators, the need for vibration reduction during rescue operation is often low. In such cases, the HK 20137914 A 15 load weight parameter may be omitted.

[0052] FOURTH EMBODIMENT The first to third embodiments explained the cases in which the hoisting speed during rescue operation of the car is adjusted by controlling the inverter 12 via the arc control unit 41 of the power supply control device 40, and by alternating between periods in which the hoisting motor 20 is operated and periods in which it is stopped. The fourth embodiment will describe the case in which the hoisting speed of the car during rescue operation by controlling the dynamic brake 32 to alternately set periods during which the hoisting motor 20 is operated and periods during which it is stopped. Descriptions identical to those in the first embodiment are omitted.

[0053] Figure 9 is a block diagram of the elevator control device 100 according to the fourth embodiment. In the elevator control device 100 according to Embodiment 4, the speed adjustment device 50 controls the dynamic brake 32 rather than the arc control unit 41 of the power supply control device 40. The operation of the speed adjustment device 50 is the same as described in the first embodiment.

[0054] The dynamic brake 32 is controlled to open and close according to the speed control pattern as shown in Figure 4(b). During the high-level period as shown in Fig. 4(b), the dynamic brake 32 is in the on-state, and power is supplied from the inverter 12 to the hoisting motor 20. In addition, during the low-level period as shown in Fig. 4(b), the dynamic brake 32 is in the off-state, and power is no longer supplied from the inverter 12 to the hoisting motor 20.

[0055] During rescue operation, the speed control unit 50 of the elevator control device HK 20137914 A 16 100 adjusts the hoisting speed and acceleration of the car by controlling the dynamic brake 32 in alternating on / off periods, thereby suppressing car vibration (swaying and rattling).

[0056] Furthermore, the speed control unit 50 of the elevator control device 100 turns the dynamic brake 32 on and off according to a speed control pattern in which the on‑period gradually increases until the car hoisting speed reaches a predetermined value, becomes fixed once that speed is reached, and gradually decreases as the hoisting speed decreases. As a result, the elevator control device 100 can further reduce the car acceleration and further suppress car vibration (swaying and rattling) during rescue operation.

[0057] Furthermore, in the elevator control device 100 according to the fourth embodiment, an embodiment in which the car load weight is not considered as a parameter is also conceivable.

[0058] Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These new embodiments may be implemented in various other forms, and various omissions, substitutions, and modifications may be made without departing from the spirit and scope of the invention. These embodiments and their variations are included within the scope and spirit of the invention and within the scope of the invention and its equivalents as described in the claims. REFERENCE SIGNS LIST

[0059] HK 20137914 A 17 1 commercial power source 2 battery 10 power supply device 11 converter 12 inverter 20 hoisting motor 31 drum brake 32 dynamic brake 40 power supply control device 41 arc control unit 42 brake control unit 43 abnormality detection unit 431 temperature measurement unit 432 speed measurement unit 50 speed adjustment device 51 memory unit 52 extraction unit 53 car position detection unit 54 load weight detection unit 55 control signal generation unit 61 brake release command reception unit 62 power failure detection unit 63 earthquake detection unit 200 remote control device HK 20137914 A 18 What is claimed is: 1. An elevator control device for controlling supply of power from an inverter that supplies power to a hoisting motor for driving an elevator car, the elevator control device comprising: a power supply control device including an arc control unit that controls an output power of the inverter by adjusting a pulse width of a PWM signal that turns switching elements constituting the inverter on and off and a brake control unit for controlling a brake that restrains rotation of the hoisting motor, and a speed adjustment device that adjusts a hoisting speed during rescue operation of the car by alternately providing an on-period during which the PWM signal output by the arc control unit is allowed to be output, and an off-period during which the arc control unit stops outputting the PWM signal. 2. The elevator control device as claimed in claim 1, wherein the speed adjustment device includes: a memory unit that stores information on multiple speed control patterns that derive changes in the car hoisting speed corresponding to combinations of the travel distance from the car stopping position to the nearest floor's stopping position and the car load weight, an extraction unit that extracts information on the corresponding speed control pattern from the memory unit based on information regarding the travel distance from the car stopping position to the nearest floor's stopping position and information regarding the car load weight, and a control signal generation unit that generates a control signal to control the inverter via the arc control unit based on the extracted speed control pattern’s information. 3. The elevator control device as claimed in claim 2, wherein the speed adjustment device adjusts the hoisting speed and acceleration of the car by adjusting an on-period during which the arc control unit is permitted to output the PWM signal and an off-period during which the arc control unit stops outputting the PWM signal. 4. The elevator control device as claimed in claim 3, wherein the speed control pattern is configured such that the time width of the on-period increases sequentially until the car hoisting travel speed reaches a predetermined speed, when the car hoisting speed reaches the predetermined speed, the time width of the on-period becomes constant, HK 20137914 A 1 and when the car hoisting speed decreases, the time width of the on-period sequentially decreases. 5. The elevator control device as claimed in any one of claims 1 to 4, wherein the speed adjustment device controls the power supply control device to initiate rescue operation of the elevator based on at least one of manual operation by an operator, remote operation from a remote control device, power failure detection, or earthquake detection. 6. In an elevator having an inverter that supplies power to a hoisting motor for driving a car of the elevator, and a dynamic brake disposed between the inverter and the hoisting motor, an elevator control device for controlling supply of power from the inverter to the hoisting motor, the elevator control device comprising: a power supply control device including an arc control unit that controls an output power of the inverter by adjusting a pulse width of a PWM signal that turns switching elements constituting the inverter on and off and a brake control unit for controlling a brake that restrains rotation of the hoisting motor, and a speed adjustment device that adjusts a hoisting speed during rescue operation of the car by controlling an on-period during which the dynamic brake is turned on and an off-period during which the dynamic brake is turned off. 7. The elevator control device as claimed in claim 6, wherein the speed adjustment device includes: a memory unit that stores information on multiple speed control patterns that derive changes in the car hoisting speed corresponding to combinations of the travel distance from the car stopping position to the nearest floor's stopping position and the car load weight, an extraction unit that extracts information on the corresponding speed control pattern from the memory unit based on information regarding the travel distance from the car stopping position to the nearest floor's stopping position and information regarding the car load weight, and a control signal generation unit that generates a control signal to control the inverter via the arc control unit based on the extracted speed control pattern’s information. 8. The elevator control device as claimed in claim 7, wherein the speed control pattern is configured such that an on-period, during which the dynamic HK 20137914 A 2 brake allows power to be supplied to the hoisting motor, and an off-period, during which the dynamic brake stops supplying power to the hoisting motor, are arranged alternately. 9. The elevator control device as claimed in claim 8, wherein the speed control pattern is configured such that the time width of the on-period increases sequentially until the car hoisting travel speed reaches a predetermined speed, when the car hoisting speed reaches the predetermined speed, the time width of the on-period becomes constant, and when the car hoisting speed decreases, the time width of the on-period sequentially decreases. 10. The elevator control device as claimed in any one of claims 6 to 9, wherein the speed adjustment device controls the power supply control device to initiate rescue operation of the elevator based on at least one of manual operation by an operator, remote operation from a remote control device, power failure detection, or earthquake detection. HK 20137914 A 3 POWER SUPPLY DEVICE ARC CONTROL UNIT ABNORMALITY DETECTION UNIT BRAKE CONTROL UNIT SPEED MEASUREMENT UNIT TEMPERATURE MEASUREMENT UNIT BRAKE RELEASE COMMAND RECEPTION UNIT POWER FAILURE DETECTION UNIT EARTHQUAKE DETECTION UNIT CONTROL SIGNAL GENERATION UNIT CAR POSITION DETECTION UNIT LOAD WEIGHT DETECTION UNIT POWER SUPPLY CONTROL DEVICE EXTRACTION UNIT MEMORY UNIT SPEED ADJUSTMENT DEVICE REMOTE CONTROL DEVICE (REMOTE CONTROL ) GATE CONTROL SIGNAL 1 2 10 11 12 32 20 31 M 40 41 52 42 43 431 432 50 51 53 54 55 63 62 61 200 100 C O N V ER T E R Fig. 1 DRUM BRAKE RELEASE SIGNAL HK 20137914 A 1 TIME MAXIMUM LIMITATION SPEED THE AREA OF THE TRAPEZOID REPRESENTS THE TRAVEL DISTANCE T1 T2 T3 SET SPEED T0 HOISTING SPEED TIME MAXIMUM LIMITATION SPEED THE AREA OF THE TRIANGLE REPRESENTS THE TRAVEL DISTANCE T1 T2 T3 SET SPEED T0 HOISTING SPEED Fig. 2 Fig. 3 HK 20137914 A 2 HOISTING SPEED TIME MAXIMUM LIMITATION SPEED TIME THE AREA OF THE TRAPEZOID REPRESENTS THE TRAVEL DISTANCE T1 T2 T3 SET SPEED SPEED CONTROL PATTERN T0 TIMEDRUM BRAKE RELEASE SIGNAL （ａ） （ｂ） （ｃ） Fig. 4 HK 20137914 A 3 TIME T1T0 Toff Toff Toff Toｎ Toｎ ToｎToｎ Fig. 5 HK 20137914 A 4 START RESCUE OPERATION S13 SELECT SPEED ADJUSTMENT PATTERN END RESCUE OPERATION ACQUIRE CAR POSITION AND LOAD WEIGHT INFORMATION S11 DRUM BRAKE RELEASE EXECUTE INVERTER CONTROL CHECK TEMPERATURE,SPEED,AND CURRENT STOP RELEASING DRUM BRAKE STOP INVERTER IS ANY ABNORMALITY DETECTED? CONTINUE RELEASING DRUM BRAKE CONTINUE RESCUE OPERATION S14 S15 S18S16 S17 S19 Ｙｅｓ Ｎｏ CALCULATE TRAVEL DISTANCE S12 Fig. 6 HK 20137914 A 5 （ａ） （ｂ） （ｃ） TIME Toff Toff Toｎ Toｎ Toｎ TIME TIME SPEED CONTROL PATTERN GATE CONTROL SIGNAL BEFORE SPEED ADJUSTMENT GATE CONTROL SIGNAL AFTER SPEED ADJUSTMENT Fig. 7 HK 20137914 A 6 HOISTING SPEED （ａ） （ｂ） （ｃ） TIME MAXIMUM LIMITATION SPEED THE AREA OF THE TRAPEZOID REPRESENTS THE TRAVEL DISTANCE T1 T2 T3 SET SPEED SPEED CONTROL PATTERN T0 DRUM BRAKE RELEASE SIGNAL Toff Toｎ Fig. 8 TIME TIME HK 20137914 A 7 POWER SUPPLY DEVICE ARC CONTROL UNIT ABNORMALITY DETECTION UNIT BRAKE CONTROL UNIT SPEED MEASUREMENT UNIT TEMPERATURE MEASUREMENT UNIT BRAKE RELEASE COMMAND RECEPTION UNIT POWER FAILURE DETECTION UNIT EARTHQUAKE DETECTION UNIT CONTROL SIGNAL GENERATION UNIT CAR POSITION DETECTION UNIT LOAD WEIGHT DETECTION UNIT POWER SUPPLY CONTROL DEVICE EXTRACTION UNIT MEMORY UNIT SPEED ADJUSTMENT DEVICE REMOTE CONTROL DEVICE （REMOTE CONTROL） 1 2 10 11 12 32 20 31 M 40 41 52 42 43 431 432 50 51 53 54 55 63 62 61 200 100 C O N V ER T E R Fig. 9 HK 20137914 A 8

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