FI121204B - Arrangements for power supply to a lift - Google Patents

Description

Field of the Invention

The invention relates to a DC / DC converter according to the preamble of claim 1.

5 Prior Art

The power requirement of the elevator varies according to the load and the control situation. For example, during acceleration, the power requirement is momentarily more than twice the power required at steady speed. In this case, the current taken up by the elevator from the supply network of the building will also vary and, for example, dimensioning of the fuses 10 in the building's electrical supply must be made according to the maximum supply current of the elevator. The elevator also restores some of the energy bound to the system during generator operation of the elevator motor. This energy returned to the power supply system has traditionally been converted to heat in a separate power supply or returned to the supply network.

Efforts have been made to balance the variations in power taken from the supply network by adding temporary energy stores to the power supply system of the elevator, which supply part of the instantaneous power required during heavy load, and receive energy returned to the power supply system during generator operation.

US2003 / 0089556 discloses an emergency power use of an elevator in which a low-voltage energy storage device is incorporated in a power supply system comprising conventional low-voltage supercapacitors containing activated carbon. The capacitors are connected to the intermediate circuit of the frequency converter by means of power supply means, which also make a voltage adaptation by dropping the intermediate circuit voltage to fit supercon-25 capacitors.

WO2007 / 086863 discloses a special nano-gate based double-layer 2 electrochemical capacitor, which is said to have a better energy storage capacity than conventional supercapacitors.

OBJECT OF THE INVENTION It is an object of the present invention to provide the use of a new type of double-layer high-voltage ceramic capacitor ceramic as an energy store for an elevator. One such potential high voltage capacitor is disclosed, for example, in WO2006 / 026136 A2. It is a further object of the invention to provide an arrangement of a high-voltage ceramic double-layer capacitor as part of an elevator power supply system. The energy storage device according to the invention can be used to smooth out variations in the power flow of the power supply of the elevator system.

Characteristics of the Invention

The DC / DC power converter according to the invention is characterized by what is stated in the characterizing part of claim 1. Other aspects of the invention 15 are characterized by what is stated in claim 2. The inventive embodiments are also disclosed in the specification of this application. The inventive content contained in the application may also be defined otherwise than as set forth in the claims below. The inventive content can also consist of several separate inventions, especially if the invention is considered in the light of the express or implied subtasks, or in terms of the benefits or groups of benefits achieved. Thus, some of the attributes contained in the claims below may be redundant for individual inventive ideas.

The DC / DC power converter according to the invention is adapted to supply power between the first low-voltage direct voltage and the second high-voltage direct voltage, such as the voltage of a ceramic two-layer high-voltage capacitor. Said power converter comprises at least a first switching unit comprising two series-connected switching elements and a choke arranged between the lower-voltage direct voltage and the center of the series-switching of said switching elements. Said power converter comprises, in addition to said first chopper unit, at least a second chopper unit arranged in series with the first chopper unit. Said low-voltage dc voltage can be, for example, the voltage between the negative circuit and the positive intermediate circuit rail of the te-5 motor feeder of the motor. The voltage of the ceramic double-layer high-voltage capacitor can then be raised above the intermediate circuit voltage by means of a power converter.

An elevator power supply arrangement according to the invention comprises an elevator motor and an elevator power supply circuit. The power supply arrangement also comprises a ceramic double-layer high-voltage capacitor fitted in connection with the elevator roller bronze supply circuit. The elevator motor is connected to the elevator power supply circuit, and the elevator motor power supply is effected, for example, from a mains voltage supply or a generator connected to the power supply circuit. Power can be supplied through the power supply circuit to other elevator systems such as elevator shaft electrification, elevator lighting, and elevator control electronics or brakes. The ceramic double-layer high-voltage capacitor according to the invention may be connected directly to the power supply circuit of the elevator or via a separate power converter. In those embodiments of the invention in which the elevator power supply circuit comprises a motor intermediate circuit power supply device, the ceramic dual-layer high-voltage capacitor may also be directly fitted between the positive and negative intermediate circuit buses of the motor intermediate circuit power supply device. If the power supply of the high-voltage capacitor is controlled by a separate power converter, such as a DC / DC power converter, the voltage between the poles of the ceramic dual-layer high-voltage capacitor can also be raised higher than said intermediate circuit voltage.

In a method of supplying power in an elevator system according to the invention, an elevator motor is fitted to the elevator power supply arrangement; adapting the elevator power supply circuit to the elevator power supply arrangement; and fitting a ceramic two-layer high-voltage condenser-30 condenser to the elevator power supply circuit 4

Advantages of the Invention

Among other things, the invention provides at least one of the following advantages: - The high-voltage ceramic double-layer capacitor according to the invention

The voltage between the 5 terminals of the condenser may be the DC / DC according to the invention

power converter raises to high, for example about 3500 volts. The energy available for storage in a capacitor is squarely proportional to the voltage between the capacitor terminals mentioned, and such a high-voltage capacitor can charge 10 more energy than the low-voltage supercapacitors of the prior art. In this case, the size of the energy storage is also smaller than known, and such energy storage is easy to place in connection with the elevator system. This is particularly advantageous in so-called machine-room-less elevators, where energy reserves can be placed in connection with power control of a 15-kapa elevator motor, for example in an elevator shaft.

The power supply arrangement according to the invention makes it possible to equalize the variation of power drawn from the power source of the elevator, such as a mains voltage or a generator. Since the design of the power supply and shields, such as fuses, is based on the peak power absorbed by the elevator, the design of the 20 power supplies can then be reduced and a smaller electrical connection will be provided. Electricity billing in buildings is also determined, at least in part, by the peak power, which also results in cost savings as the connection decreases.

The DC / DC power converter according to the invention reduces the voltage stress on a single component, such as a switching element, which makes it possible to adapt commercial, commonly used components to control the high-voltage ceramic double-layer capacitor of the invention.

5

The ceramic double-layer high-voltage capacitor can also be placed directly in, for example, an intermediate circuit of a motor power supply device. This is possible because the capacitor voltage duration is sufficient for this, for example, in prior art motor power supplies where the 5 dc voltage is directly rectified from the mains voltage, for example the 230 dc supply voltage is approximately 560 volts. Since no separate DC / DC power converter of this kind is needed, the power supply arrangement of the elevator is simplified.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described in more detail with reference to the accompanying drawings, in which:

Figure 1 illustrates an elevator power supply arrangement

Figure 2 shows another power supply arrangement for the elevator

Figure 3 shows one power converter 15 Figure 4 shows another power converter

Figure 1 shows an elevator power supply arrangement. The power supply arrangement comprises an elevator power supply circuit 2. A ceramic double-layer high-voltage capacitor 3 is disposed in connection with the elevator power supply circuit.

Figure 2 shows an elevator power supply arrangement. Here, the power supply circuit 2 of the elevator comprises a motor low-power power supply 5 and a power converter 6 arranged between the power supply intermediate circuit 4,4 'and the ceramic 25-layer high-voltage capacitor 3. As an intermediate circuit power supply device 5 of the motor, a frequency converter is used. The power supply of the elevator motor 1 is controlled by the inverter control 22. The ceramic double-layer 6 high voltage capacitor is again charged and discharged by the converter control 7. During heavy load or motor operation of the motor 1, 1 required power from the ceramic high voltage capacitor 3 to the drive intermediate circuit 4.4 'via the power converter 6. When restoring the potential or kinetic energy bound to the elevator system in the generator drive of the elevator motor 1 back to the drive intermediate circuit 4.4 ', at least part of the recovered power is supplied via the power converter 6 to . The operating state of the motor 1 can also be determined, for example, by measuring the DC link voltage of the drive, since in the generator drive the DC link voltage begins to increase.

The dual-layer high-voltage capacitor 3 can also be directly fitted to the motor power supply intermediate circuit 4,4 ', whereby a separate power converter 6 may not be required.

Figure 3 shows a power converter 6. The power converter is arranged between the intermediate circuit voltage 4,4 'and the high-voltage ceramic double-layer capacitor 20 3. The voltage matching between the intermediate circuit voltage and the voltage of the high voltage capacitor is made by the transformer 9. The power converter comprises switch arrangements 10,11 which comprise a series connection of a diode and a controlled switch, such as an igbt transistor. The switches are arranged in these arrangements so that power supply between the intermediate circuit voltage 4,4 'and the high voltage capacitor 3 is possible in both directions. The voltage between the poles of the high-voltage capacitor 3 is up to 3500 volts, and in the switch arrangements of Fig. 3, the switches are subjected to a voltage stress equal to the voltage between the poles of the capacitor, which must be taken into account.

Figure 4 shows another power converter 6. The power converter comprises 30 first 19, second 7 and third 8 chopping units. Each of the harvester units 7 comprises a choke 13,16 and two series-connected switching elements 14,15,17,18. The choke 13 of the first switching unit 19 is disposed between the positive intermediate busbar 4 of the DC power supply device 5 of the motor and the center 20 of the coupling elements 14,15 of the first switching unit. The choke 16 of the second chopping unit 7 is disposed between the first switching element 14 of the first chopping unit 19 and the center of the serial connection of the switching elements 17,18 of the second chopping unit. The second switching element 18 of the second switching unit is disposed between the center of the serial connection of the switching elements of the second switching unit and the positive intermediate busbar 4 of the DC intermediate circuit 10. A third chopping unit 8 is disposed in series with the first and second chopping units respectively, and the third chopping unit is connected to the positive terminal of the ceramic double-layer high-voltage capacitor 3. The negative terminal of the high-voltage capacitor 3, in turn, is connected to the negative intermediate circuit 15 of the motor power supply 5, whereby the power supply between the intermediate circuit 4,4 'of the motor power supply 5 and the ceramic high-voltage capacitor 3 can be controlled.

In the power converter of Fig. 4, a capacitor 12 can be connected in parallel to the series connection of the first and second switching elements 14, 15, 17, 18 of each switching unit, whereby the voltage variation across the series connection is reduced.

The invention is not limited only to the above exemplary embodiments, but many modifications are possible within the scope of the inventive idea defined by the claims.

Claims (2)

A DC / DC power inverter (6), comprising at least a first switching unit (19) comprising two sets of n coupled switching elements (14,15) and a choke (13) arranged at a lower voltage DC (4) 5 and between said center switching center (20) of said switching elements, characterized in that the power converter (6) comprises at least a second switching unit (7) in series with the first switching unit (19) and that the power converter is adapted to supply power to the first low voltage 4, 4 ') and the secondary voltage of the second higher voltage ceramic double-layer high-voltage capacitor (3). Power converter according to claim 1, characterized in that the choke (16) of the second chopping unit (7) is disposed between the first switching element (14) of the first chopping unit (19) and the center of the switching elements (17,18) of the second chopping unit. the second switching element (18) of the second switching unit is disposed between the center of the serial connection of the switching elements of the second switching unit and said lower voltage direct voltage (4).