JPH07211562A - Reactor for measures against emi and converter provided with it - Google Patents

Abstract

PURPOSE:To make a high-power-factor converter small and low-cost by integrating a reactor for a chopper with a choke coil for measures against an EMI. CONSTITUTION:A reactor 32 for a chopper and a choke coil 31 for measures against an EMI are arranged and constituted on the same core, and a reactor 3 with a built-in EMI filter is formed. In addition, the reactor 3 is connected to the rear stage of a diode bridge 2. A high-power-factor converter is constituted together with a switching element 4, for a chopper, whose current flow rate is controlled by a chopper control circuit 7, with a diode 5 and with a capacitor 6. The converter is used as a front-stage DC power supply for a power conversion apparatus such as an inverter 8 or the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reactor having a choke coil having a high impedance with respect to a disturbing frequency band component as a measure against EMI and a reactor having the reactor in its rectifying / smoothing section for subsequent power conversion. The present invention relates to a converter having a high power factor of its AC input during operation of the device.

[0002]

2. Description of the Related Art Conventionally, a power factor of an AC input of a power conversion device such as an inverter has been achieved by controlling a conduction ratio of a switching element of a chopper of the power conversion device before the power conversion device is in operation. In the converter,
Along with the chopping control reactor (hereinafter referred to as the chopper reactor) that makes the DC current flow intermittent,
As a measure against EMI, it is known that a choke coil having a high impedance with respect to a disturbed frequency band component is installed separately from the chopper reactor on the input AC side or the output DC side of the rectification unit of the converter.

[0003]

As described above, in the conventional high power factor converter, the chopper reactor and the EMI countermeasure choke coil are separately installed. Therefore, in the converter, the choke coil is used. There was an increase in space and price associated with the separate placement of the coil.

In view of the above, it is an object of the present invention to integrate the chopper reactor and the EMI countermeasure choke coil, and to reduce the size and cost of the high power factor converter.

[0005]

In order to achieve the above object, an EMI countermeasure reactor of the present invention and a converter provided with the same are provided as follows: 1) According to claim 1, the EMI countermeasure reactor is provided for a disturbance frequency band component. It is assumed that a choke coil having a high impedance and a reactor having a predetermined inductance corresponding to chopping control of the energized current are arranged on the same core.

2) According to claim 2, the converter is
AC input rectifier circuit, a reactor inserted in series to either positive or negative output bus of this rectifier circuit, and a switching element inserted in parallel via this reactor so as to short-circuit the output side of the rectifier circuit during its control. , A series connection circuit in which a capacitor charged through the reactor and a diode inserted in the charging path in a forward direction are connected in series and connected in parallel to both ends of the switching element. With a desired DC output voltage with a voltage, by controlling the switching element according to a predetermined conduction ratio to open and close, in the converter intended to increase the power factor of its AC input during the operation of the subsequent stage power converter, The reactor is an EMI according to claim 1.
Measures shall be taken as a reactor.

[0007]

In the converter, the chopper reactor and the EMI countermeasure choke coil each have a core forming a magnetic path, and the core can be shared by the core material and the winding structure selected. . According to a first aspect of the present invention, the chopper reactor and the EMI countermeasure choke coil are arranged and configured on the same core to form an EMI countermeasure reactor, and the overall physical size and cost of the both are reduced. It is intended, and claim 2
By applying the EMI countermeasure reactor to the converter as described above, the size and cost of the converter can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the circuit diagram of FIG. FIG. 1 shows the mutual relation between the EMI countermeasure reactor as described above, a high power factor converter using this reactor, an inverter as a power converter using this converter as a preceding stage DC power supply unit, and its load induction motor. It is a circuit diagram.

In FIG. 1, 1 is an AC power source, 2 is a diode bridge as an AC rectifier circuit, 3 is a reactor with a built-in EMI filter, that is, an EMI countermeasure reactor, and a choke coil 31 as an EMI filter element arranged on the same core. And chopper reactor 32, 4 is a chopper switching element whose conduction ratio is controlled by chopper control circuit 7, 5 is a diode, 6 is a capacitor, 8 is an inverter, and 9 is a load of this inverter. It is an induction motor.

Here, each of the elements 2 to 7 is an inverter 8
A converter that forms the DC power supply on the upstream side of
A DC voltage of 282 V is output with an AC voltage of 00 V as an input, and a high power factor of the converter AC input during operation of the inverter 9 is achieved by appropriate current control using the current flowing through the reactor 32 as an input signal. Is possible.

[0011]

According to the present invention, as described in claim 1, the choke coil having a high impedance with respect to the disturbance frequency band component and the chopper reactor having a predetermined inductance are arranged on the same core. The EMI countermeasure reactor is also used, and the second aspect is also provided.
As described above, by applying the EMI countermeasure reactor to the high power factor converter that controls the chopping conduction ratio of the reactor current, the fault frequency band component blocking choke coil and the chopper reactor can be provided in the converter. It is possible to reduce the installation space associated with the choke coil and reduce the man-hours required for wiring, etc., as compared with a conventional converter in which each converter is installed separately. It is also possible to reduce the size and cost of a power conversion device such as an inverter.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a high power factor converter system showing an embodiment of the present invention.

[Explanation of symbols]

1 AC power supply 2 Diode bridge 3 EMI filter built-in reactor (EMI countermeasure reactor) 4 Chopper switching element 5 Diode 6 Capacitor 7 Chopper control circuit 8 Inverter 9 Induction motor 31 Choke coil 32 Chopper reactor

Claims (2)

[Claims] 1. A choke coil having a high impedance with respect to a disturbance frequency band component, and a reactor having a predetermined inductance corresponding to chopping control of a current flowing through the choke coil are arranged on the same core. EMI countermeasure reactor. 2. A rectifier circuit for AC input, and a reactor inserted in series in either positive or negative output bus of the rectifier circuit,
A series connection of a switching element inserted in parallel through the reactor so that the output side of the rectifier circuit is short-circuited during its control, a capacitor charged through the reactor and a diode inserted in the forward direction in the charging path. And a series connection circuit connected in parallel to both ends of the switching element to form a required DC output voltage with the voltage across the capacitor, and controlling the switching of the switching element in accordance with a predetermined conduction ratio. A converter designed to increase the power factor of its AC input during operation of the subsequent power converter, wherein the reactor is the EMI countermeasure reactor according to claim 1.