JP2002369387A - Distributed power source - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problems of a high cost and complicated device structure, which are raised when regenerative power from an elevator is regenerated on a power supply side, in a distributed power source which is interconnected with a power distribution system, and supplies power to a load comprising a motor for an elevator. SOLUTION: A converter for a power source is composed of a forward conversion portion 12 for converting AC power from a micro gas turbine generating set 12 into DC power, and an inversion portion 13 which converts the DC power supplied through the conversion portion 13 or DC power regenerated from a motor IM for an elevator into AC power and is interconnected to a power distribution system. A connector for an elevator is composed of an inversion portion 15 which converts the DC power supplied through the forward conversion portion, or DC power supplied from the power distribution system through the inversion portion into AC power, and drives the motor for an elevator. In the case where DC power is generated using a fuel cell, etc., by the generating set, the converter for a power source is composed of only the inversion portion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a distributed power supply which is connected to a power distribution system and supplies power to a load including an elevator, and more particularly to a power supply circuit of a converter for an elevator.

[0002]

2. Description of the Related Art A distributed power source of this type includes a fuel cell or a micro gas turbine generator that enables a cogeneration system, a wind power generator and a solar power generator that use natural energy. There is a method using the power source as a power source, and a method using them together.

In order to convert DC to AC, a distributed power supply converter that adjusts frequency, voltage and phase to the system is indispensable for a distributed power supply connected to a distribution system. Is provided with a voltage adjusting means for preventing reverse power flow to the system, and further provided with a voltage distortion rate improving means for preventing a harmonic from flowing out to the system and a harmonic suppression filter means. Further, an AC reactor is provided for preventing a short-circuit current source for a short-circuit of a system load.

[0004] Here, the distributed type power supply connected to the distribution system includes, as loads, not only general loads such as lighting and OA equipment, but also AC machines such as elevators, escalators, and air conditioners which have a relatively large power capacity. There is a load.

[0005] Among them, the elevator frequently converts the AC power into DC power by a forward conversion unit and frequently converts the AC power into AC power whose frequency and voltage are controlled by an inverse conversion unit in order to frequently raise and lower the car and to accelerate and decelerate the elevator car. An elevator converter for converting is provided. Also, in the elevator, regenerative power is generated when the elevator car is lowered, so the elevator converter is provided with a dynamic braking device or a power regeneration mechanism.

FIG. 2 shows a conventional elevator converter. The power generation device of the distributed power source 1 generates, for example, a generator using a micro gas turbine as a prime mover, converts the generated power into an alternating current by a distributed power source converter including a forward converter and an inverse converter, And enable interconnection. In addition, when a fuel cell is used as a power source, the power generator is connected to a power distribution system by converting its DC output into AC at an inverse converter.

The elevator converter obtains DC power from a linked AC power supply through a non-fuse breaker NFBM, a power line filter PLF, an electromagnetic contactor MC, etc., to a rectifier RF, and converts the DC power into a frequency and an inverse converter INV. Converts voltage to controlled AC power. This conversion is performed by the control unit CON.
The elevator car (induction machine or synchronous machine) IM can be driven up and down by forward and reverse rotation control and speed control of the elevator motor IM. The regenerative electric power from the electric motor IM is regenerated to a DC circuit by an inverse converter, and when the DC voltage is going to rise to a set value or more, the dynamic braking transistor D
Turn on the BTR and set the dynamic brake resistor D
Let BR consume as heat energy.

In such an elevator converter, the regenerative electric power from the motor is consumed as heat by the resistor DBR, so that the energy is not effectively used.

Therefore, as shown in FIG. 3, there is a converter with a regenerative function capable of regenerating regenerative power to the power supply side. In this converter, the dynamic brake circuit of FIG. 2 is omitted, a PWM forward converter is provided in place of the rectifier RF, and the power regenerated in the DC circuit is converted into AC by the PWM forward converter by PWM control, and the power supply is connected to the power supply. And regenerate to the power supply side. The AC reactor ACL, the line-to-line capacitor C, and the like are for removing harmonic components contained in the regenerative electric power.

[0010]

In the conventional converter for an elevator, in the configuration shown in FIG. 2, the power regenerated from the elevator motor cannot be used on the power supply side, and the energy cannot be effectively used. In this regard, in the configuration of FIG. 3, the regenerative power can be returned to the power supply side, and the energy can be used effectively.

However, the PWM forward conversion unit composed of a power semiconductor device such as an IGBT requires reverse conversion control, which leads to an increase in cost. Further, in the control unit forward conversion, it is necessary to perform the inverse conversion M control in the PWM control forward conversion unit, and the control circuit becomes complicated. Further, it is necessary to add an AC reactor ACL or the like.

An object of the present invention is to provide a distributed power supply that regenerates regenerative electric power from an elevator to a power supply side, and that can simplify the device configuration and reduce costs.

[0013]

According to the present invention, a distributed power source is provided with a reverse converter for converting the power generated by a power generator into DC power by a forward converter or directly extracting DC power and converting the DC power into AC power. Focusing on having, the forward converter of the power converter is also used as the forward converter of the elevator converter, or the DC power output of the power generator is used as the DC power supply of the elevator converter, and the inverse converter is connected to the system. The present invention solves the above-mentioned problem by being used as an interconnection means and also as an inverse conversion means for regenerating the regenerative electric power from the converter for the elevator to the power supply side, and is characterized by the following configuration.

(1) A distributed power supply which converts power generated by a power generator into AC power by a power converter and connects the power to a distribution system to supply power to a load including an elevator motor. A converter for converting AC power from the power generator into DC power, and converting DC power supplied through the forward converter or DC power regenerated from the elevator motor to AC power. And an inverter that is connected to the power distribution system, and the elevator converter is connected to the DC power supplied through the forward converter of the power converter or from the power distribution system through the inverter of the power converter. It is characterized by comprising an inverse converter for converting the supplied DC power into AC power and driving the elevator motor.

(2) When the power generator generates DC power, the power converter converts the DC power or DC power regenerated from the elevator motor into AC power and connects the AC power to a distribution system. Characterized in that it is constituted by an inverse transform unit.

[0016]

FIG. 1 is a block diagram of a distributed power supply according to an embodiment of the present invention, in which a power generator is a micro gas turbine power generator.

The micro gas turbine power generator 11 has a compressor, a turbine, a combustor, etc., rotates the turbine at a high speed, and drives the generator from the turbine via a speed reducer or the like to generate power.

The AC power generated by the generator is converted into DC power by the forward converter 12 of the distributed power supply. For this conversion, a voltage control function is provided for the case where an existing distributed power supply is used, but a rectifier configuration can also be used.

The inverse converter 13 converts the DC power converted by the forward converter 12 into AC power whose frequency or the like is controlled for interconnection with the power distribution system, and supplies the AC power to the power distribution system through an AC reactor ACL, a power line filter PLF, and the like. Enables interconnection with The control of the forward conversion unit 12 and the inverse conversion unit 13 for this interconnection is performed by the power control unit 14 by gate control of a semiconductor element such as an IGBT.

Here, the DC power converted by the forward converter 12 serving as the DC section of the distributed power supply is supplied to the non-fuse breaker N
It is supplied as DC power to the inverse converter 15 of the elevator converter through the FBM, the electromagnetic contactor MC, and the like. The elevator control unit 16 performs intended AC output control by gate control of a semiconductor element such as an IGBT in the inverse conversion unit 15.

In the above configuration, the distributed power supply can supply DC power to the inverse converter 15 of the elevator converter through the forward converter 12. In addition, the distributed power supply can supply the surplus power to another load by the inverse converter 13 in connection with the distribution system side. Also, the regenerative electric power from the elevator motor IM can be regenerated to the power distribution system by the inverse converter 13. When the power generated by the distributed power source is insufficient, the DC power can be supplied from the distribution system to the inverse converter 15 of the elevator converter by operating the inverse converter 13 as a rectifier.

As described above, the present embodiment can realize a distributed power supply that can be connected to a system while having a power regeneration function on the power supply side, similarly to a conventional converter for an elevator with a regeneration function. In addition, since the forward converter of the distributed power source is also used as the forward converter of the elevator converter, the IGBT and the like of the main circuit can be reduced and the control circuit can be omitted. The AC reactor ACL and the power line filter PLF required for both the converters for the elevator can be reduced by half, and the cost can be significantly reduced.

In the embodiment, a case is shown in which the distributed power supply is a micro gas turbine power generator. However, the present invention is not limited to this, and a power supply in combination with a fuel cell or a solar cell can be used. . In the case of these fuel cells and solar cells, DC power is generated. Therefore, if the desired power generation voltage can be secured, the forward conversion unit 12 can be omitted. When the voltage is low, a step-up chopper or the like may be used.

[0024]

As described above, according to the present invention, the forward converter of the power converter is also used as the forward converter of the elevator converter, or the DC power output of the power generator is used as the DC power of the elevator converter. In addition, since the reverse conversion unit is used as a means for interconnection with the system and also serves as the reverse conversion means for regenerating the regenerative power from the converter for the elevator to the power supply side, the regenerative power from the elevator is regenerated to the power supply side. In addition, the apparatus configuration can be simplified to reduce costs.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a distributed power supply according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional distributed power supply and a converter for an elevator.

FIG. 3 is a configuration diagram of a conventional converter for an elevator with a regenerative function.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Power generation device 12 ... Forward conversion part 13 ... Inversion part 14 ... Power supply control part 15 ... Inverter reverse conversion part 16 ... Elevator control part IM ... Elevator motor

Claims (2)

[Claims] 1. A distributed power supply for converting power generated by a power generator into AC power by a power converter, interconnecting the power with a distribution system, and supplying power to a load including an elevator motor. The converter is a forward converter that converts AC power from the power generator into DC power, and converts DC power supplied through the forward converter or DC power regenerated from the elevator motor into AC power. An inverter converter is connected to the distribution system, and the elevator converter is supplied from the distribution system through DC power supplied through the forward converter of the power converter or through the inverse converter of the power converter. A distributed power supply comprising an inverse converter for converting the DC power to AC power to drive the elevator motor. 2. When the power generating device generates DC power, the power converter converts the DC power or DC power regenerated from the elevator motor into AC power and connects the AC power to a distribution system. 2. The distributed power source according to claim 1, wherein the distributed power source is configured by an inverse conversion unit.