JP5527995B2 - Load drive device - Google Patents

Description

  The present invention relates to a load driving device having a backup function in the event of a power failure.

  A vibration damping device incorporated in a control object such as a high-rise building or a ship usually includes a movable mass provided movably in the vibration direction of the control object, and is used for external force (vibration) acting on the control object. On the other hand, the external force (vibration) is positively canceled by applying a reverse force to the movable mass. Further, in a load driving device that drives a vibration damping device (load) using a motor, regenerative power generated in the motor is recovered by kinetic energy (deceleration force) applied to the load, and this regenerative power is collected by a capacitor (capacitor). The information is also stored and reused (see, for example, Patent Documents 1 and 2).

JP-A-10-26706 JP 2007-325342 A

  By the way, it is considered to incorporate a backup function for dealing with a power failure in this type of load driving device. Incidentally, this kind of backup function is realized by using an uninterruptible power supply device generally called UPS. In this type of uninterruptible power supply (UPS), a part of the electric power received through the power receiving facility and supplied to the load driving device main body is stored in the secondary battery. The power stored in the secondary battery is supplied to the load driving device main body. However, the backup capability by the uninterruptible power supply (UPS) is generally about several hundred milliseconds, which is insufficient as a backup function of the load driving device.

  Therefore, an emergency generator that generates electric power independently from the commercial power supplied to the power receiving facility is used in combination with the above-described uninterruptible power supply (UPS). It is considered to back up with an emergency generator. However, even if the emergency generator is started in conjunction with the start of the backup operation by the uninterruptible power supply, it takes time to start up the emergency generator. Therefore, the uninterruptible power supply requires the emergency generator to start up. Backup capacity (power capacity) that exceeds time is required. Therefore, for example, there is a problem that a large capacity uninterruptible power supply device having a backup capability of 1 minute or more is required and the equipment cost is increased.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a load drive device having a simple configuration that realizes a backup function against power failure at low cost and energy efficiency.

  The present invention pays attention to a technique for accumulating and regenerating the regenerative power generated by the kinetic energy (deceleration force) applied to the load by the motor that drives the load in the capacitor (capacitor), and accumulated in the capacitor (capacitor). If it is configured to back up the drive of the motor using regenerative power energy, it is possible to realize a backup function at the initial time of a power failure without using an uninterruptible power supply device, for example, while effectively using the regenerative power. Pay attention.

Therefore, in order to achieve the above-described object, the load driving device according to the present invention is:
<a> a motor that receives driving power to drive a load and generates regenerative power from kinetic energy applied to the load;
<b> a converter that converts AC power obtained through the power receiving facility into DC power;
<c> An emergency generator for supplying AC power to the converter instead of the power receiving facility;
<d> An inverter that supplies DC power obtained through the converter as drive power to the motor and that collects regenerative power obtained through the motor;
<e> a load control device that controls the operation of the inverter according to the state of the load and the operating state of the motor;
<f> A DC power output from the converter or a regenerative power recovered by the inverter, and a capacitor that outputs the stored power through the inverter, for example, an electric double layer capacitor. Especially,
<g> Estimating the amount of power stored in the capacitor, controlling the operation of the converter so that the estimated amount of power is a constant amount satisfying a predetermined backup capability, and the estimated amount of power is a preset power A power control device is provided that starts the emergency generator when the amount is reduced to a certain level.

By the way, the power control device, for example, varies the current limit value of the converter and controls the electric energy stored in the capacitor to be constant to a predetermined target electric energy, and also stores the electric energy stored in the capacitor. Is configured to start up the emergency generator when the amount of power is reduced to an amount of power that can supply power to the inverter over the time required to start up the generator. For the amount of power stored in the capacitor, for example, an output voltage of the capacitor (electric double layer capacitor) is detected, and an average obtained by removing periodic fluctuations of the load from the detected voltage using, for example, a notch filter The load may be estimated as a DC voltage. The load is a vibration control device that performs acceleration / deceleration operation according to the behavior of the control target, or a loading / unloading machine that is driven to accelerate / decelerate, and the motor supplies driving power. In response, the load is accelerated, and regenerative power is generated along with the deceleration operation of the load.

  According to the load drive device having the above configuration, the regenerative power obtained from the motor is stored in the capacitor (electric double layer capacitor) and reused as the drive power of the motor. Backup operation is performed by effectively using the stored power, and the emergency generator is started according to the degree of decrease in the amount of power stored in the capacitor, thus realizing a backup function with high operational reliability at low cost. can do. In addition, since a large-capacity uninterruptible power supply (UPS) is not required, the apparatus cost can be reduced accordingly. In addition, the amount of power stored in the capacitor (electric double layer capacitor) can be managed and set in anticipation of the amount of regenerative power generated by the motor, so that the required power capacity of power receiving equipment, emergency generators, etc. can be reduced. Etc. are produced.

1 is a schematic configuration diagram of a load driving device according to an embodiment of the present invention. The figure which shows the structural example of the feedback control system with respect to a braking device. The figure which shows the structural example of the electric power control apparatus in the load drive device shown in FIG.

Hereinafter, a load driving device according to an embodiment of the present invention will be described with reference to the drawings.
This load driving device drives a vibration control device that moves a movable mass (load) back and forth with, for example, a motor (actuator) and suppresses rolling of a building (high-rise building). Incidentally, the vibration damping device operates by receiving driving power to drive the movable mass (load) 1 and generates a regenerative power from kinetic energy (rolling vibration) applied to the movable mass (load) 1. ) 2 is the main constituent.

  The load drive device has a function of energizing and driving the motor 2 described above under the control of the load control device 3 and collecting the regenerative power generated in the motor 2 as shown in FIG. The provided inverter 4 is provided. This inverter 4 basically operates with a converter (AC / DC converter) 6 that converts AC power received from a commercial power supply system via DC power receiving equipment 5 into DC power, as a power source. For example, it is of a type that controls the driving of the motor 2 by the PWM method. The converter 6 has a function of controlling the DC output voltage and limiting the DC output current. An emergency generator 7 that is driven by an internal combustion engine or the like and generates AC power independently of the above-described commercial power supply system is provided in parallel to the power receiving facility 5, and when the commercial power supply system is powered off, It plays the role of supplying AC power to the converter 6 in place of the power receiving facility 5.

  Further, in the intermediate circuit that feeds the DC power output from the converter 6 to the inverter 4, a part of the DC power output from the converter 6 is accumulated and the regenerative power recovered via the inverter 4 is stored. , Specifically, an electric double layer capacitor 8 is provided. The electric power stored in the capacitor (electric double layer capacitor) 8 is supplied to the inverter 4 and reused.

  Basically, the power control device 9 in the load driving device constructed as described above estimates the amount of power stored in the capacitor (electric double layer capacitor) 8 from the terminal voltage of the capacitor 8, for example. The operation of the converter 6, particularly its output current, is controlled so that the predetermined amount of power becomes a preset constant amount of power Pstd, and the estimated amount of power as described above is the preset lower limit power amount Pmin (<Pstd It plays a role of starting the emergency generator 7 when the voltage drops to.

  Incidentally, the lower limit electric energy Pmin cannot be obtained from the converter 6 due to a power failure, and gradually the power stored in the capacitor (electric double layer capacitor) 8 is supplied to the inverter 4 instead of the converter 6. The accumulated power amount of the capacitor 8 that decreases to at least the capacitor 8 over a period of time from when the emergency generator 7 is started up to a state where the emergency generator 7 can generate a predetermined amount of power. To the inverter 4 from the amount of power that can be continuously supplied. Therefore, by detecting that the power amount of the capacitor 8 has decreased to the lower limit power amount Pmin and starting the emergency generator 7, all of the power stored in the capacitor 8 is supplied to the inverter 4. The emergency generator 7 is started up before power is supplied from the emergency generator 7 to the inverter 4 via the converter 6.

  Here, the power control device 9 regards the amount of power stored in the capacitor 8 as the terminal voltage (capacitor voltage) Vout of the capacitor 8, and operates the converter 6 and the emergency generator 7, respectively. Configured to control. Specifically, the power control device 9 includes a voltage detection unit 9a that detects a terminal voltage (capacitor voltage) Vout of the capacitor 8, and a capacitor voltage Vout detected by the voltage detection unit 9a. The notch filter 9b that removes (suppresses) the fluctuation component associated with the operation, and the operation of the converter 6 based on the capacitor average voltage Vave obtained via the notch filter 9b, and the capacitor average voltage Vave are set in advance. And a power control unit 9c that controls the start-up of the emergency generator 7 in comparison with the determined threshold value.

  Here, the vibration damping device described above will be described. This vibration damping device vibrates the movable mass 1 in the opposite direction with respect to the roll (vibration) acting on the building that is the control target. The lateral vibration (vibration) is positively canceled (vibrated). For this purpose, the load control device 3 feedback-controls the operation of the inverter 4 according to the swing angular velocity of the building and the rotation angle of the motor 2 detected by, for example, a speed sensor (not shown) provided in the building. Thus, the rotational speed of the motor 2 is controlled.

  Incidentally, the feedback control of the motor 2 by the load control device 3 is realized by using a control system configured as shown in FIG. 2, for example, as introduced in Patent Documents 1 and 2 described above. . Specifically, the swing angular velocity of the building and the swing angle that is an integral component thereof are obtained, and the rotational angle of the motor 2 and the rotational angular velocity of the motor 2 that is a differential component thereof are obtained. The amount of displacement of the movable mass 1 that can cancel the roll (vibration) of an object is obtained as a rotation angle command value of the motor 2. Then, the difference between the rotation angle command value obtained by the control arithmetic unit 3a and the current rotation angle of the motor 2 is obtained by the difference unit 3a as a control amount necessary for accelerating / decelerating the motor 2. This is achieved by multiplying the quantity by a coefficient specific to the feedback control system to obtain a command value required to drive the motor 2. In addition, what is necessary is just to integrate the shake angular acceleration twice when calculating | requiring the shake angular acceleration of a building using an acceleration sensor.

  Therefore, as described above, the vibration damping device controls the operation of the motor 2 to generate a force for suppressing the roll by displacing the movable mass 1 in the opposite direction with respect to the roll (vibration) of the building. As a matter of course, the motor 2 is accelerated / decelerated in accordance with the rolling (vibration) of the building. Incidentally, the acceleration of the motor 2 is performed by energizing and driving the motor 2 via the inverter 4, and conversely, the deceleration of the motor 2 generates regenerative power in the motor 2 by the force applied from the movable mass 1 to the motor 2. Is done by.

  The capacitor (electric double layer capacitor) 8 described above is used to collect and store the regenerative power generated in the motor 2 in this way, and to reuse the stored power for driving the motor 2. Therefore, the power energy (storage capacity) stored in the capacitor 8 increases as the regenerative power is stored, and decreases as the motor 2 is driven. Accordingly, the power energy (storage capacity) stored in the capacitor 8 and thus the terminal voltage Vout of the capacitor 8 change as the motor 4 is driven by the inverter 4 and the regenerative power is recovered. Moreover, since the acceleration (power running) and deceleration (regeneration) of the motor 2 are performed in synchronization with the rolling (reciprocating vibration) of the building, the fluctuation cycle of the terminal voltage Vout of the capacitor 8 is specific to the building. It becomes 1/2 times of the rolling period T.

  On the other hand, in the power control device 9, the capacitor 8 described above collects and stores the regenerative power from the motor 2, and the stored regenerative power can be reused for driving the motor 2. In order to prevent wasteful consumption of power energy by feeding only the amount of power obtained by subtracting the reusable regenerative power amount from the maximum power amount necessary for driving the power to the capacitor 8, The output current of the converter 6 is feedback-controlled according to the stored electric energy. At this time, since the amount of electric power stored in the capacitor 8 periodically changes with the power running and regeneration of the motor 2, the fluctuation frequency component is removed by using the notch filter 9b, whereby the capacitor 8 The average amount of power stored in is calculated. Specifically, the average value (average voltage) Vave of the terminal voltage Vout of the capacitor 8 is obtained.

  In the power control unit 9 c, the amount of power required for driving (powering) the motor 2 is the sum of the amount of power regenerated and reused by the motor 2 and the amount of power fed through the converter 6. By controlling the amount of power supplied from the converter 6 in a feedback manner, specifically, by limiting the output current of the converter 6, the amount of power (power energy) supplied from the converter 6 is minimized. It has become something to suppress. Specifically, as shown in the configuration example of the power control unit 9c in FIG. 3, the average voltage Vave of the capacitor 8 obtained through the notch filter 9b and the amount of power required for driving (powering) the motor 2 described above are as follows. The difference between the target voltage determined to be the sum of the amount of electric power regenerated and reused by the motor 2 and the amount of electric power fed through the converter 6 is obtained, and according to the difference voltage A current limit value (control value) used for feedback control of the converter 6 is obtained. The feedback control of the converter 6 is performed, for example, by constructing a PI control system.

  However, since the power supply through the converter 6 is stopped when the commercial power supply system fails, even if the condenser 8 collects the regenerative power from the motor 2, the motor 2 is driven (powering). Along with this, the amount of power energy stored in the capacitor 8 gradually decreases. Specifically, the average terminal voltage Vave of the capacitor 8 gradually decreases with a power failure. Therefore, in this apparatus, as shown in FIG. 3, in the power control unit 9, it is determined by the comparator 9d whether or not the average voltage Vave of the capacitor 8 has decreased to a preset voltage lower limit value Vmin. When a decrease in the average voltage Vave is detected, an activation signal for activating the emergency generator 7 is generated.

  The voltage lower limit value Vmin used for this determination corresponds to the aforementioned lower limit electric energy Pmin, and at least the emergency generator 7 generates a predetermined electric energy from the electric energy remaining in the capacitor 8. This is a threshold value for determining whether or not the amount of power that can continuously supply power to the inverter 4 is satisfied over a period of rising to a possible state. Accordingly, when the emergency generator 7 is started by generating a start signal when the average voltage Vave of the capacitor 8 is lowered to the voltage lower limit value Vmin, all of the power energy accumulated in the capacitor 8 is used up. Since the emergency generator 7 starts up before, it is possible to reliably back up the vibration damping device from a power failure of the commercial power supply.

  Thus, according to the load driving device configured as described above, the regenerative electric power obtained from the motor 2 of the vibration damping device is recovered in the capacitor 8 and reused for driving the motor 2. The amount of power to be supplied to the power can be reduced by the amount corresponding to the regenerative power amount. Specifically, in a two-axis vibration control device, when four motors 2 with a rated 55 kW are driven, the inverter 4 is required to have an electric capacity of 220 kW (= 55 kW × 4). In order to satisfy such a power requirement, a 350 KVA converter 6 is generally required. Further, as a power receiving facility, an emergency generator, and an uninterruptible power supply, an electric capacity of 350 KVA is provided with an allowance for each. It is necessary to prepare things.

  In this regard, if a configuration including, for example, a 60 F capacitor (electric double layer capacitor) 8 that accumulates the regenerative power of the motor 2 as described above is employed, the theoretical capacity of the converter 6 is approximately 110 KVA. It is sufficient for the power receiving facility 5 and the emergency generator 7 to have an electric capacity of about 150 KVA even if a margin is expected. Therefore, the required electric capacity of the power supply system for the inverter 4 including the converter 6 can be greatly reduced, and the equipment cost can be reduced even if the capacitor 8 is newly required.

  Further, according to the above-described configuration, the power stored in the capacitor 8 is used to back up the operation of the vibration control device at the time of a power failure, and before the power stored in the capacitor 8 is completely consumed, Since the generator 7 can be reliably started up, the operation of the vibration damping device can be reliably backed up in combination with the backup of the vibration damping device by the capacitor 8. In particular, since the emergency generator 7 is activated when a decrease in the amount of power stored in the capacitor 8 is detected, the conventional emergency generator 7 was activated by detecting a power failure in the commercial power system. Unlike the control method, there is no problem that the emergency generator 7 is started even if an instantaneous power failure occurs. Further, there is an effect that it is not necessary to determine whether or not the power failure is an instantaneous power failure.

  The present invention is not limited to the embodiment described above. Here, the load driving device that drives the vibration damping device that suppresses the rolling applied to the building has been described as an example. However, the controlled object may be a cargo handling machine or a lifting device that is driven to accelerate or decelerate. As the capacitor 8, it is preferable to use a small and large-capacity electric double layer capacitor, but it is of course possible to use a large-capacity electrolytic capacitor or the like. Further, the motor 2 may be a so-called linear actuator that is reciprocally driven. In addition, the electric capacity of the inverter 4 and the converter 6 and the like is not limited to the values exemplified in the embodiment as long as it conforms to the specifications of the vibration control device that is the control target. In short, the present invention can be implemented with various modifications without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 Movable mass 2 Motor 3 Load control device 4 Inverter 5 Power receiving equipment 6 Converter 7 Emergency generator 8 Capacitor (electric double layer capacitor)
9 Power control device

Claims (3)

A motor that receives driving power to drive a load and generates regenerative power from kinetic energy applied to the load;
A converter that converts AC power obtained through the power receiving facility into DC power;
An emergency generator for supplying AC power to the converter instead of the power receiving facility;
An inverter that supplies DC power obtained through the converter as drive power to the motor, and that collects regenerative power obtained through the motor;
A load control device for controlling the operation of the inverter according to the state of the load and the operating state of the motor;
While accumulating DC power output from the converter or regenerative power recovered by the inverter, a capacitor that outputs the accumulated power via the inverter;
The amount of power stored in the capacitor is estimated by estimating the amount of power stored in the capacitor and varying the current limit value of the converter so that the estimated amount of power is a constant amount that satisfies a predetermined backup capability. The emergency control is performed when the electric energy accumulated in the capacitor is reduced to an electric energy that can supply electric power to the inverter over the time required for starting up the generator . A load driving device comprising a power control device for starting a generator.   The capacitor is an electric double layer capacitor, and the amount of electric power stored in the capacitor detects an output voltage of the electric double layer capacitor and removes a periodic fluctuation of the load from the detected output voltage. The load driving device according to claim 1, wherein the load driving device is estimated as an average DC voltage. The load is a vibration damping device that performs an acceleration / deceleration operation according to the behavior of a controlled object, or a loading / unloading machine that is accelerated / decelerated,
The load driving device according to claim 1, wherein the motor receives driving power, accelerates the load, and generates regenerative power along with the deceleration operation of the load.

Images