JP2004248390A - Semiconductor power converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor power converter capable of diagnosing degradation of short-circuit protection fuses for a semiconductor element even during operation of the semiconductor power converter. <P>SOLUTION: Each of the short-circuit protection fuses 4 for protecting the semiconductor power converter from a short circuit due to a fault in the semiconductor elements 3, is provided with a temperature sensor 5 for detecting the temperature of the short-circuit protection fuse 4; and a controller 6 fetches sensor signals outputted from the respective temperature sensors 5 and continuously monitors the sensor signals during the operation of the semiconductor power converter. When the temperatures of the short-circuit protection fuses 4 become lower than a predetermined value, the degradation of the short-circuit protection fuses 4 is determined. Thus, the degradation of the short-circuit protection fuses for the semiconductor element can be diagnosed even during the operation of the semiconductor power converter. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor power conversion device, and more particularly to a semiconductor power conversion device capable of performing deterioration diagnosis of a short-circuit protection fuse for a semiconductor element.
[0002]
[Prior art]
2. Description of the Related Art In a semiconductor power conversion device, a short-circuit protection fuse for a semiconductor device (hereinafter abbreviated as a short-circuit protection fuse) is connected in series with the semiconductor device in order to protect the power conversion device from a short circuit due to a failure of the semiconductor device.
[0003]
By the way, in order to cope with the deterioration of the fuse, the fuse conventionally used in the control circuit of the electric motor or the like is switched to the spare second fuse when the fuse is blown due to the spontaneous deterioration of the fuse and the alarm is issued. There is one in which a circuit is operated (for example, see Patent Document 1).
[0004]
In the case of a protective relay consisting of a fuse and a protection relay, the operating characteristics of the protection relay and the degradation start characteristics of the fuse are stored, and when an accident current value exceeding the rated current value occurs, the fault current value is handled. If the time required to shut off the protection relay to be activated is longer than the fuse degradation start time corresponding to the fault current value, a fuse degradation history is determined to have occurred and a warning is output (for example, see Patent Document 2). .).
[0005]
However, in the semiconductor power conversion device, conventionally, there is no means for determining the aging or fatigue deterioration of the short-circuit protection fuse during operation of the device.
[0006]
[Patent Document 1]
Japanese Utility Model Publication No. 7-18120 (page 2-3, FIG. 1)
[Patent Document 2]
JP-A-8-236006 (page 4-5, FIG. 2-4)
[0007]
[Problems to be solved by the invention]
As described above, in the conventional semiconductor power conversion device, since there is no means for determining aging or fatigue deterioration of the short-circuit protection fuse during operation of the device, deterioration cannot be determined, and operation of the device cannot be determined. Was stopped, the short-circuit protection fuse was removed from the apparatus, and a unit test was not performed. Therefore, in a semiconductor power converter that uses semiconductor elements connected in parallel, even if one short-circuit protection fuse deteriorates and no longer conducts, the operation can be continued with a healthy circuit composed of other fuses and semiconductor elements connected in parallel. In this case, there is a possibility that a heavy load is imposed on a sound short-circuit protection fuse and a semiconductor element without noticing deterioration.
[0008]
The present invention has been made in view of such a conventional point of view, and an object of the present invention is to provide a semiconductor power conversion device capable of performing deterioration diagnosis of a short-circuit protection fuse for a semiconductor element even during operation of the device. .
[0009]
[Means for Solving the Problems]
In order to achieve the above object, a semiconductor power conversion device according to the present invention is provided in each of a semiconductor element short-circuit protection fuse for protecting the power conversion device from a circuit short circuit due to a failure of a semiconductor element. A temperature sensor that detects the temperature of the protection fuse and a short-circuit protection fuse for the semiconductor element that detects the temperature of each of the short-circuit protection fuses for the semiconductor element during operation of the device and constantly monitors the sensor signals output from each of the temperature sensors. Means for determining that the semiconductor element short-circuit protection fuse has deteriorated when the temperature of the semiconductor device has dropped below a predetermined value.
[0010]
According to the present invention having such a configuration, deterioration diagnosis of the short-circuit protection fuse for a semiconductor element can be performed even during operation of the apparatus.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0012]
FIG. 1 is a diagram showing a schematic configuration of an embodiment of a semiconductor power conversion device according to the present invention.
[0013]
In FIG. 1, reference numeral 1 denotes an AC power supply, and 2 denotes a rectifier (for example, a thyristor rectifier) that converts the AC power supply into a DC power supply. The rectifier 2 includes, for example, rectifiers of each phase of U, V, W, and X, Y, and Z, as shown in the figure, and corresponds to one semiconductor element (for example, a thyristor element) 3 and a power converter. The configuration is the same as the configuration of the conventional semiconductor power conversion device up to the configuration in which a plurality of circuits in which a short-circuit protection fuse 4 for protecting from a short circuit due to a failure of 3 is connected in series are connected in parallel.
[0014]
In this embodiment, as shown in FIG. 1, in addition to a conventional configuration, a deterioration diagnosis device for a short-circuit protection fuse including a temperature sensor 5 and a control device 6 is provided. That is, a temperature sensor 5 for detecting the temperature of the short-circuit protection fuse 4 is attached to each short-circuit protection fuse 4, and the temperature of the short-circuit protection fuse 4 is detected and the sensor signal output from each of the temperature sensors 5 is transmitted to the control device 6. And constantly monitor the sensor signal during the operation of the converter. When the short-circuit protection fuse 4 is deteriorated, the impedance of the short-circuit protection fuse 4 increases and the current becomes difficult to flow. It is configured to diagnose.
[0015]
Next, the deterioration diagnosis operation of the short-circuit protection fuse in this embodiment will be described with reference to the control flow shown in FIG.
[0016]
First, during operation of the converter, the sensor signal output from each of the temperature sensors 5 is taken into the control device 6, so that the temperature of each short-circuit protection fuse 5 is input. The temperature data of the fuse 5 is divided into data for each phase as follows (step S201).
[0017]
U phase: Tu-1, Tu-2,..., Tu-n
V phase: Tv-1, Tv-2,..., Tv-n
………………………………………………
Z phase: Tz-1, Tz-2,..., Tz-n
Next, after calculating the average values Ta-u, Ta-v,..., Ta-z of the fuse temperatures of each phase and the standard deviations σu, σv,. Next, a deviation value of each fuse temperature is calculated (step S202).
[0018]
U-phase No. 1: Su-1 = (Tu-1-Ta-u) / σu × 10 + 50
U-phase No. 2: Su-2 = (Tu-2-Ta-u) / σu × 10 + 50
………………………………………………
Z-phase nth: Sz-n = (Tz-n-Ta-z) / σz × 10 + 50
Then, the calculated deviation values Su-1, Su-2,..., Sz-n of the respective fuse temperatures are compared with the deterioration determination value L of the fuse. Then, a deterioration diagnosis is performed for each of the short-circuit protection fuses 4 (step S203).
[0019]
This deterioration diagnosis operation is repeated at a predetermined cycle during the operation of the converter.
[0020]
As described above, according to this embodiment, it is not necessary to stop the operation of the converter for the deterioration diagnosis of each short-circuit protection fuse 4 and remove the short-circuit protection fuse from the converter and perform a unit test. Even during the operation of the apparatus, the deterioration diagnosis of the short-circuit protection fuse 4 can be performed. Therefore, even if some of the short-circuit protection fuses 4 are deteriorated, by replacing them based on the diagnosis result, it is possible to prevent an increase in the load on the sound short-circuit protection fuses 4 and the semiconductor element 3 beforehand. Become.
[0021]
【The invention's effect】
As described above, according to the semiconductor power conversion device of the present invention, deterioration diagnosis of the short-circuit protection fuse for a semiconductor element can be performed even during operation of the device.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of a semiconductor power conversion device according to the present invention.
FIG. 2 is a control flowchart for explaining a deterioration diagnosis operation of the short-circuit protection fuse according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... AC power supply 2 ... Rectifier 3 ... Semiconductor element 4 ... Short circuit protection fuse 5 ... Temperature sensor 6 ... Control device

Claims (1)

A temperature sensor provided in each of the semiconductor element short-circuit protection fuses for protecting the power conversion device from a circuit short-circuit due to a failure of the semiconductor element, and detecting a temperature of the semiconductor element short-circuit protection fuse; The temperature of each of the short-circuit protection fuses is detected and the sensor signal output from each of the temperature sensors is constantly monitored. When the temperature of the short-circuit protection fuse for a semiconductor element falls below a predetermined value, the short circuit for the semiconductor element is short-circuited. Means for determining that the protection fuse has deteriorated.

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