JP4089824B2 - Surplus energy recovery device - Google Patents

Description

  The present invention relates to a surplus energy recovery device that recovers surplus energy such as regenerative energy of a motor to a commercial system.

  A motor, which is an electric motor that drives the elevator car up, generates regenerative energy when the car is lowered by its own weight. In some prior art, this regenerative energy is supplied to a resistor to generate Joule heat, Dissipate. The problem with this prior art is that the regenerative energy is dissipated, so it is desirable to make effective use of the regenerative energy.

  Another prior art is shown in FIG. The commercial AC power of the commercial system 1 is given from the line 2 to the motor 4 through the conversion circuit 3. The conversion circuit 3 includes a converter 5 that converts the alternating current of the line 2 into direct current, and an inverter 7 that converts the direct current from the converter 5 via the line 6 into alternating current, and the alternating current output of the inverter 7 is supplied to the motor 4. Given. The motor 4 functions to elevate an elevator car, for example. The regenerative energy generated by the motor 4 when the car descends is converted to direct current by the inverter 7, converted to alternating current by another inverter 8 provided in the conversion circuit 3, and connected to the commercial system via the line 2. Collected. Further, the line 2 is connected to another device 9 to be supplied with electric power, and surplus energy of the device 9 is connected to the commercial system of the line 2 via the inverter 11 and recovered. The line 2 is supplied with electric power from, for example, the fuel cell 13 that is the power supply device 12 by being converted into an alternating current by the inverter 14. Moreover, the electric power from the synchronous generator 16 of the other power supply device 15 is converted into a direct current by the converter 17, converted into an alternating current by the inverter 18, and supplied to the line 2, and thus the commercial system 1 is interconnected.

  The new problem of the prior art shown in FIG. 8 is that it is necessary to install individual inverters 8 and 11 for each of the motors 4 and the devices 9 that generate regenerative energy. The cost is high.

  An object of the present invention is to provide a surplus energy recovery device that recovers regenerative energy of a motor, effectively reuses surplus energy, and simplifies the configuration.

The present invention includes a plurality of motors,
A plurality of converters 25 that are provided for each motor and convert the AC power of the commercial system into DC,
A plurality of first inverters 27 that convert the DC output from each converter into an alternating current and apply it to the motor, and convert the alternating current regenerative energy from the motor into a direct current;
DC bus,
A plurality of regenerative energy interconnection circuits 33 for providing a DC output from each first inverter in common with a DC bus;
The surplus energy recovery apparatus includes a second inverter 34 that is connected to a commercial system by converting the direct current of the direct current bus into an alternating current.

The present invention also includes power sources 38 and 43 other than the commercial system,
And power supply interconnection circuits 41 and 46 that supply the output of the power supply in association with the DC bus.

  According to the present invention, the AC power of the commercial system is converted into direct current by the converter in each of the plurality of motors, and the converted direct current output is converted into alternating current by the first inverter and supplied to each motor. The The motor is an electric motor such as an induction motor or a synchronous motor.

  Each of the plurality of motors is independently operated, for example, at random, for example, for each elevator car, a motor that individually raises the car, and generates regenerative energy when the car descends Or a motor that drives a pump such as an axial flow pump or a centrifugal pump that generates regenerative energy by the inertia of rotation, or a motor that drives other loads. There may be a configuration in which other loads are driven to generate regenerative energy due to inertia or the like.

  The AC regenerative energy from the motor is converted to DC by the first inverter, and DC power is applied to the DC bus by the regenerative energy interconnection circuit. A second inverter is connected to the DC bus, and the DC of the DC bus is converted into an AC by the second inverter and linked to a commercial system. Therefore, the second inverter may be a single unit, for example, and it is not necessary to individually install the second inverter for each of a plurality of motors, and as a result, the configuration can be simplified. The regenerative energy interconnection circuit prevents the motor regenerative energy voltage from becoming abnormally high, thereby preventing dielectric breakdown and preventing damage to the electric circuit elements.

  A distributed power source other than the commercial system, such as a fuel cell or a synchronous generator, is connected to the DC bus via a power supply interconnection circuit, and power from the power source is applied to the DC bus. In this way, the power of the DC bus provided from the power source is provided by being linked to the commercial system via the second inverter.

The present invention also includes a motor,
A converter 25 for converting commercial AC power to DC;
A first inverter 27 that converts the DC output from the converter into an alternating current and applies it to the motor, and converts the AC regenerative energy from the motor into a direct current;
DC bus,
A first interconnection circuit 33 for providing a DC output from the first converter in linkage with a DC bus;
Non-commercial power sources 38, 43;
Second inverters 72 and 74 for providing the output of the power source and the output of the DC bus in connection with a commercial system;
A surplus energy recovery device comprising: second interconnection circuits 77 and 81 for providing a direct current of a direct current bus to a second inverter.

Further, the present invention is characterized in that a power storage unit 84 is connected to the DC bus.
In the present invention, the power source is
It is the fuel cell 38 and / or the rotary generator 43.

  According to the present invention, as will be described later with reference to FIG. 7, the AC power of the commercial system is converted to DC by the converter, and the DC output from the converter is converted to AC by the first inverter. Given to the motor. The AC regenerative energy from the motor is converted into a direct current by the first inverter described above, and given to a single common direct current bus by the first interconnection circuit. Outputs from a power source other than the commercial system, for example, a fuel cell that is a distributed power source or a synchronous generator driven by a prime mover, are converted into an alternating current by the second inverter and linked to the commercial system. The second inverter is supplied with the output of the DC power of the DC bus connected to the second inverter by the second interconnection circuit. Thus, the output of the DC bus is also given to the commercial system via the second interconnection circuit and the second inverter.

  In order to reliably prevent the voltage of the DC bus from becoming abnormally high due to the regenerative energy of the motor or the control delay of the distributed power source, a power storage unit may be connected to the DC bus. The power storage unit may be (a) a secondary battery such as a storage battery, but (b) a motor driven by the DC power of the DC bus, and a configuration in which the flywheel is driven to rotate by the motor. (C) a configuration in which a current continues to flow including a superconducting coil element may be included, and (d) other configurations may be realized.

  According to the present invention, the regenerative energy of the motor is applied to the DC bus and connected to the commercial system by, for example, a single inverter, thereby simplifying the configuration and sending the regenerative energy to the commercial system. Furthermore, it is possible to prevent an abnormally high voltage from being generated due to the recovered energy in the DC bus.

  According to the present invention, conventionally, when measures for recovering surplus energy are taken for each individual device, the capacity of each device is required, and thus the device cost has become enormous. Accordingly, the capacity can be reduced, and a plurality of devices can be easily connected in relation to the DC bus. Furthermore, in the prior art, since the voltage, current value, and method of the DC unit for each individual device are various, it was impossible to connect them together. A device of the kind can be connected in connection with the DC bus, ensuring the recovery of surplus energy. Furthermore, in the present invention, not only a function of utilizing electric energy but also electric energy can be supplied, and the present invention can be implemented as a power supply source.

  FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention. AC power from the commercial system 21 via the line 22 is supplied to a plurality of motors 23 via a conversion circuit 24 for each motor 23. The conversion circuit 24 includes a converter 25 that converts the AC power of the line 22 into DC and derives it to the line 26, and a first inverter 27 that converts the DC output from the converter 25 via the line 26 into AC and supplies it to the motor 23. A plurality of combinations of the motor 23 and the conversion circuit 24 are provided, and each of these motors 23 may be a motor that drives an elevator car that operates independently, for example, at random, or an axial pump or A motor for driving a pump such as a centrifugal pump may be used, and a motor with another load may be used. The motor 23 is realized by an electric motor such as an induction motor or a synchronous motor.

  In the DC bus 31, the regenerative energy of the motor 23 is converted to DC by the first inverter 27, and is supplied to the regenerative energy interconnection circuit 33 via the line 32. The output of the interconnection circuit 33 is supplied to the DC bus 31. Given to. The direct current power of the direct current bus 31 is converted into an alternating current by the second inverter 34 and connected to the commercial system 21 via the line 22.

  The AC power of the commercial system 21 via the line 22 is also supplied to the device 35 that generates surplus energy, and the device 35 is driven. The device 35 may be a power storage device such as an RF (redox flow) or NaS battery, or any other configuration, as long as it supplies power and then cuts off the power supply to generate surplus energy. Good. The DC power that is the regenerative energy of the device 35 is linked to the bus 31 via the regenerative energy interconnection circuit 37.

  Further, DC power from the fuel cell 38 constituting the distributed power source is connected to the DC bus 31 via the line 39 by the power supply interconnection circuit 41 to the bus 31. Further, in the power supply device 42, for example, AC power of a rotary generator that is driven to rotate by a prime mover such as an internal combustion engine, for example, a synchronous generator 43, is converted into a direct current by a converter 44, and from a line 45 by a power interconnection circuit 46 It is given by being linked to the bus 31. As described above, in the configuration in which the fuel cell 28 and the power supply device 42 are connected to the DC bus 31 via the interconnection circuits 41 and 46 as described above as a distributed power source, the required power is linked with the control function of the distributed power source. Are output from the distributed power supply, the power interconnection circuits 41 and 46 perform the control operation.

  The output voltage of the lines 32 and 36 may be 300V, for example, and the DC voltage derived from the fuel cell 38 to the line 39 is 30V, for example. The DC voltage derived from the power supply device 42 to the line 45 may be 300 V, for example. The DC voltage of the DC bus 31 may be 300V, for example. The interconnection circuits 33, 37, 41, and 46 perform such voltage and / or current control, output DC power to the bus 31, and convert surplus electrical energy to AC in a batch by the inverter 34 for commercial use. Regenerate to electric power.

  FIG. 2 is an electric circuit diagram showing a specific configuration of the converter 25. The commercial system 22 is, for example, a three-phase AC power source, and each phase of the line 22 supplies DC power to the line 26 via the diodes D1 to D3 in the positive half cycle, and the diodes D4 to D6 in the negative half cycle. Power is supplied through. The diodes D1 and D4 are connected in series, the diodes D2 and D5 are connected in series, the diodes D3 and D6 are connected in series, and each of these DC circuits is connected between a pair of lines 26.

FIG. 3 is an electric circuit diagram showing a specific configuration of the inverter 27. A capacitor 51 is connected between the pair of lines 26, and a series circuit composed of transistors Tr1 to Tr6 connected in series is connected in parallel between these lines 26, and a series circuit composed of these transistors Tr1 to Tr6. A three-phase AC line 28 is connected to each connection point. A switching control signal is individually given to the transistors Tr1 to Tr6 from the control circuit 52, and pulse width modulation is performed by these transistors Tr1 to Tr6. Instead of the transistors Tr1 to Tr6 which are switching elements, GTO, IGBT (Insulated Gate)
Bipolar Transistor) or the like.

  In this way, surplus electric energy is collectively converted from direct current to alternating current by a single inverter 34, so that there is an advantage that the capacity of the inverter 34 can be small.

  FIG. 4 is a block diagram showing a specific configuration of the regenerative energy interconnection circuit 33. The DC / DC converter 54 is interposed between the DC bus 31 and the line 32, and the DC / DC converter 54 is controlled by the control circuit 55. Thus, the control circuit 55 is a current control method, a voltage control method, or a power control method. For example, in the case of the voltage control method, the voltage of the input unit set in advance is compared with the voltage of the current input unit, When the input voltage of 32 rises above the set voltage, DC power is applied to the DC bus 31 so as to suppress the rise.

  FIG. 5 is a block diagram showing the configuration of the interconnection circuit 57 according to another embodiment of the present invention. In the above-described embodiment, a DC current of regenerative energy is output to the line 32, but in the embodiment of FIG. 5, AC power is derived to the line 32. This AC power is supplied from the line 32 to the AC / DC converter 58, converted to DC, and connected to the DC bus 31. The operation of the AC / DC converter 58 is controlled by a control circuit 59, and the control circuit 59 controls the AC / DC converter 58 by a current control method, a voltage control method, or a power control method.

  FIG. 6 is a waveform diagram for explaining the operation of the embodiment shown in FIGS. With the regenerative energy of the motor 23, the current shown in FIG. 6 (1) is derived to the line 32, and the regenerative energy is derived by being interconnected to the DC bus 31 by the interconnection circuit 33. The motor 23 is, for example, a motor that drives an elevator car up and down, and regenerative energy is generated from one motor 23 when the elevator car is lowered at random. Furthermore, the electric current shown in FIG. 6B is derived to the similar line 32 by the regenerative energy of another motor 23 provided for another elevator. Since the current derived from each of the plurality of lines 32 is given to the DC bus 31 from the regenerative energy interconnection circuit 33 at a predetermined voltage, for example, 300 V, the current of the regenerative energy is directly applied to the regenerative energy, That is, it is a value corresponding to electric power. Furthermore, the regenerative energy current shown in FIG. 6 (3) is derived from the other device 35 to the line 36, and is supplied to the DC bus 31 by the regenerative energy interconnection circuit 37. Each of the currents shown in FIGS. 6 (1) to 6 (3) is randomly generated, and these currents are given to the DC bus 31 so that the DC bus 31 has the current shown in FIG. 6 (4). As shown by reference numeral 61, a current, and hence electric power that is regenerative energy is obtained.

  As described above, power is supplied to the DC bus 31 from the fuel cell 38 and the power supply device 42 via the lines 39 and 45, and power from the power interconnection circuit 41 and 46 is applied to the DC bus 31. The additional power applied to the DC bus 31 from each of the fuel cells 38 and the power supply device 42 is gradually uneven by the distributed power sources 38 and 42 as indicated by reference numeral 62 in FIG. Can be. In this way, the combined regenerative energy 61 and the electric power 63 obtained by adding the additional electric power 62 from the fuel cell 38 and the power supply device 42 are converted into an alternating current by the inverter 34 and supplied to the commercial system 21.

  FIG. 7 is a block diagram showing an overall configuration of a surplus energy recovery apparatus according to another embodiment of the present invention. This embodiment is partially similar to the above-described embodiment, and corresponding portions are denoted by the same reference numerals and description thereof is omitted. The commercial power from the commercial system 21 via the line 22 is supplied to the motor 23 from the line 28 via the conversion circuit 24 as in the above-described system, and the motor 23 is driven. Similarly, the apparatus 35 is also supplied with commercial AC power via the line 22.

  Each power from the power supply device 71 including the fuel cell 38 and the power supply device 42 including the synchronous generator 43 is applied to the line 22. The direct current power of the fuel cell 38 is given to the inverter 72 via the line 73. Regenerative energy from each of the plurality of motors 23 is converted into a direct current by an inverter 27, and is provided in cooperation with a direct current bus 31 by a connection circuit 33 via a line 26 and a line 32. The DC power of regenerative energy from the device 35 is also supplied from the line 36 to the interconnection circuit 37 and is supplied in cooperation with the DC bus 31. The power supply device 71 includes an inverter 72 that converts the DC power of the fuel cell 38 into AC power and cooperates with the commercial system 21. The power supply device 42 converts the alternating current power of the synchronous generator 43 included in the power supply device 42 into direct current, and provides the direct current power of the converter 44 to the inverter 74 via the line 75. The electric power of the synchronous generator 43 is given in cooperation with the commercial system 21.

  The DC power of the DC bus 31 is supplied from the interconnection circuit 77 via the line 78 in cooperation with the line 73 of the power supply device 71. The DC power through the interconnection circuit 77 and the line 78 is given by the inverter 72 in cooperation with the commercial system 21 through the line 22 together with the power of the fuel cell 38.

  The motor 23 may be a single piece. Thus, the commercial system 21 is supplied with power from the power supply devices 71 and 42 via the line 22, and DC power of regenerative energy generated randomly from the motor 23 and the device 35 is applied to the DC bus 31. The power is converted into AC together with the power of the fuel cell 38 and the synchronous generator 43, which are power supply bodies, via inverters 72, 74 individually provided in the power supply devices 71, 42, and linked to the commercial system 21 via the line 22. Is done. Thus, the regenerative energy is not wastefully dissipated and consumed, and the surplus energy can be used effectively by being supplied to the commercial system 21.

  The DC power of the DC bus 31 is also supplied from the interconnection circuit 81 through the line 82 in cooperation with the line 75 of the power supply device 42. The DC power from the DC bus 31 via the interconnection circuit 81 and the line 82 is converted to AC from the line 75 to the inverter 74 together with the DC power via the synchronous generator 43 and the converter 44, and to the commercial system 21 via the line 22. Given to be connected.

  Voltage and / or current control is performed by the interconnection circuits 33, 37; 77, 81, output to the DC bus 31, surplus electrical energy is stored in the power storage body 84, and is supplied to the load as electrical energy when necessary. it can. In this way, surplus electrical energy can be regenerated into commercial power via the inverters 72 and 74 of the distributed power supply devices 71 and 42, and special devices other than the interconnection circuits 33 and 37; 77 and 81 are provided. Even without this, the electrical energy can be effectively used. By using the power storage unit 84 as a buffer, more stable operation can be performed, and effective use of electric energy can be achieved even if the grid connection inverters 72 and 74 of the distributed power supply devices 71 and 42 are not provided. Is possible.

  A power storage unit 84 is connected to the DC bus 31. The power storage unit 84 can store the DC power of the DC bus 31 and suppresses an abnormal increase in the voltage applied to the bus 31 to prevent dielectric breakdown, breakdown of electric circuit elements, and the like. The other configuration of the embodiment of FIG. 7 is the same as that of the above-described embodiment.

  The present invention can be implemented in connection with a device for controlling the constant control of received power of a distributed power source, and can also be implemented in connection with a motor that drives an elevator, a pump, and the like. As described above, the unevenness of the electric power is moderated by the distributed power source. In addition, in order to recover surplus energy in connection with a device that conventionally discards unnecessary energy as heat, it can be widely implemented.

It is a block diagram which shows the whole structure of one Embodiment of this invention. 3 is an electric circuit diagram showing a specific configuration of a converter 25. FIG. 3 is an electric circuit diagram showing a specific configuration of an inverter 27. FIG. It is a block diagram which shows the specific structure of the interconnection circuit 33 for regenerative energy. It is a block diagram which shows the structure of the interconnection circuit 57 of the other embodiment of this invention. It is a wave form diagram for demonstrating operation | movement of embodiment shown by FIGS. It is a block diagram which shows the whole structure of the recovery apparatus of the surplus energy of other form of implementation of this invention. It is an electrical circuit diagram of a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 21 Commercial system 23 Motor 24 Conversion circuit 25, 44 Converter 27, 34, 72, 74 Inverter 38 Fuel cell 31 DC bus 33, 37, 41, 46; 77, 81 Interconnection circuit 35 Device 42, 71 Power supply device 43 Synchronous power generation Machine

Claims (5)

Multiple motors ,
A plurality of converters that are provided for each motor and convert the AC power of the commercial system to DC,
A plurality of first inverters that convert the DC output from each converter into an alternating current and apply it to the motor, and convert the alternating current regenerative energy from the motor into a direct current;
DC bus,
A plurality of regenerative energy interconnection circuits for providing a DC output from each first inverter in common with the DC bus;
A surplus energy recovery device comprising: a second inverter connected to a commercial system by converting the direct current of the direct current bus into an alternating current . A power supply other than the commercial system
2. The surplus energy recovery apparatus according to claim 1 , further comprising: a power supply interconnection circuit that provides an output of a power supply in association with the DC bus . A motor,
A converter for converting commercial AC power into direct current,
A first inverter that converts the DC output from the converter into an alternating current and applies it to the motor, and converts the alternating current regenerative energy from the motor into a direct current;
DC bus,
A first interconnection circuit that provides a DC output from the first converter in linkage with a DC bus;
A power supply other than the commercial system
A second inverter that provides the output of the power source and the output of the DC bus in connection with a commercial system;
A surplus energy recovery apparatus comprising: a second interconnection circuit that provides a direct current of a direct current bus to a second inverter . 4. The surplus energy recovery apparatus according to claim 3 , wherein a power storage unit is connected to the DC bus . The power supply is
Fuel cell and / or
It is a rotary generator , The recovery apparatus of the surplus energy as described in any one of Claims 2-4 characterized by the above-mentioned .

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