JPH083145Y2 - High potential temperature abnormality detection circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a temperature abnormality detection circuit for a high-potential portion that detects a temperature abnormality in a high-potential portion of a power conversion device using a power semiconductor element. is there.

[Prior Art] FIG. 2 shows a conventional example. That is, the temperature abnormality detection circuit of the high potential portion detects the abnormal temperature rise of the high potential portion 30 by the thermoswitch 31, drives the photocoupler 32 by the detection operation of the thermoswitch 31, and causes the photocoupler 32 to generate the signal generation circuit. It operates 34 to generate an abnormal signal and transmit it to the protection circuit.

The signal generation circuit 34 is an example of a sequence circuit that controls the sequence of the system of the entire apparatus. Reference numeral 35 is a drive power supply for the signal generation circuit 34 (AC-DC regulator is used for DC input, and is connected as shown by a broken line for AC input), 36 is a drive power supply for the photocoupler 32, and 37 is a drive power supply 36.
And an insulating plate for strengthening the dielectric strength between the housing 39 and
38 is an insulating transformer of the drive power supply 36, and 40 is a high-potential insulating section.

[Problems to be Solved by the Invention] The temperature abnormality detection circuit of the high-potential portion is provided with a photocoupler 32 to insulate the detection circuit of the thermoswitch 31 having a high potential from a peripheral circuit such as a sequence circuit. An insulating transformer 38 is provided to insulate the drive power source 36 of 32 from an external AC power source that supplies power to the drive power source 36, and further, the high potential portion 30, the photocoupler 32, the drive power source 36 and the isolation transformer 38.
A high-potential insulating section 40 is provided to insulate the housing 39 from the housing.

However, the number of parts is large, the number of manufacturing steps is large, and a manufacturing error, for example, a pressure resistance defect due to an insulating plate fixing screw is induced. Further, the photocoupler 32 also becomes expensive when the withstand voltage becomes high.

Therefore, the purpose of this invention is to reduce the number of parts,
It is an object of the present invention to provide a high-potential-part temperature abnormality detection circuit that is easy to manufacture, inexpensive, highly reliable, and capable of detecting temperature abnormalities in a plurality of high-potential parts.

[Means for solving the problem]

The temperature abnormality detection circuit of the high-potential part of the present invention connects a thermoswitch that is turned on by detecting an abnormal temperature rise of the high-potential part to the secondary side of the isolation transformer, and connects the power supply to the primary side of the isolation transformer. are doing. Further, a fuse that is blown in the short-circuit state of the secondary side due to the ON operation of the thermoswitch is connected in series to the primary side, and an abnormal signal is generated from the signal generating circuit in response to the blow of the fuse.

[Action]

According to the configuration of this invention, when the temperature of the high-potential portion abnormally rises and exceeds the set value, the thermoswitch is turned on, and the secondary side of the insulating transformer is short-circuited. Therefore, a short-circuit current is induced on the primary side of the insulation transformer, and the fuse is blown. An abnormal signal is generated from the signal generating circuit in response to the blow of the fuse.

In this case, the insulation transformer insulates the high-potential portion from the signal generating circuit, so that the conventional photocoupler and its driving power supply are unnecessary. Therefore, compared to the conventional example, the number of parts is small, the manufacturing is simple, the cost is high, and the reliability is high. Moreover, since the secondary side of the insulating transformer is plural, the temperature abnormality of the high potential parts can be prevented. It is also possible to detect.

〔Example〕

An embodiment of this invention will be described with reference to FIG. That is, the temperature abnormality detection circuit of the high potential portion includes the insulation transformer 1, the thermoswitch 2, the power supply 3, and the fuse 4.
And a signal generation circuit 5.

The insulation transformer 1 is a single-phase multi-winding transformer, and the primary side has one winding and the number of windings on the secondary side depends on the number of measured points, that is, the number of high-potential portions 6 in the embodiment. The insulation strength between the primary and secondary windings, between the secondary windings, and between the windings and the housing 7 is equal to or higher than the insulation strength between the high potential portion 6 and the housing 7, respectively. The rating is for short-time use, and the rated primary voltage V _T
Is the voltage of the power supply 3 of AC100V. The percent impedance (% Z) is the primary short-circuit current I _S1 when one of the secondary windings is short-circuited while the rated primary voltage V _T is applied,
As the rated capacity P _T ,% Z = (P _T / I _S1 · V _T ).

The primary side is connected to the AC operating power supply connection portion 9 of the housing 7. The high potential portion 6 is, for example, an inverter device and has a plurality of portions. Reference numeral 8 denotes a high-potential insulating section that insulates the insulating transformer 1 and the plurality of high-potential sections 6 from the case 7, the signal generating circuit 5, its peripheral circuits, and the like.

The thermoswitch 2 is connected to the secondary side of the insulation transformer 1 and detects an abnormal temperature rise of the high potential portion 6 and turns on. The secondary side of the insulation transformer 1 is provided by the number of the high-potential section 6, the contacts (not shown) of the thermoswitch 2 are connected to each secondary side, and the temperature detection section (not shown) of each thermoswitch 2 is provided. Are arranged in each high-potential portion 6. Each secondary side forms a temperature detection circuit by the thermoswitch 2 and the secondary winding, and when the thermoswitch 2 is turned on, it becomes a short-circuited state.

The power supply 3 is connected to the primary side of the insulation transformer 1. This power source 3 is generally AC100V as described above,
It is connected to the connecting portion 9 of the housing 7 to supply power to the primary side.

The fuse 4 is connected in series to the primary side of the insulation transformer 1 and blows in the short-circuit state of the secondary side due to the ON operation of the thermoswitch 2. Fuse 4 fast blow fuse marked with the alarm contact 10 and Example, the operating current I _F are rated as the I _F <I _S1.

The signal generation circuit 5 generates an abnormal signal in response to the blow of the fuse 4. The signal generation circuit 5 is a sequence circuit including a relay Ry as an example, and is housed in a housing 7.
The input end is connected to the alarm contact 10 of the fuse 4, and the alarm contact
The operation of 10 activates the relay Ry to turn on / off the relay contact 12. Reference numeral 11 denotes a drive power source for the signal generating circuit 5, which has the same configuration as that in FIG.

The temperature abnormality detection circuit of the high potential portion is turned on when the temperature of one high potential portion 6 abnormally rises and exceeds the set value, the thermoswitch 2 performs a detection operation. When the thermo switch 2 is turned on, the secondary side of the insulation transformer 1 is short-circuited, and a short-circuit current flows in the secondary winding. Therefore, the short-circuit current I _S1 is induced in the primary side of the insulating transformer 1 and the fuse 4 is blown.
The alarm contact 10 is turned on in response to the melting of the fuse 4, the relay Ry of the signal generating circuit 5 is activated, and the relay contact 12 is turned on, so that an abnormal signal of the signal generating circuit 5 is generated.

According to this embodiment, the insulation transformer 1 insulates the high-potential portion 6 from the signal generating circuit 5, so that the conventional photocoupler 32 and its driving power supply 36 are not required. Therefore, compared with the conventional example, the number of parts is small, the manufacture is simple, the cost is low, and the reliability is high. Moreover, since there can be a plurality of secondary sides of the insulating transformer 1, it is possible to detect temperature abnormalities in a plurality of high potential portions 6.

[Advantage of the Invention] According to the temperature abnormality detecting circuit of the high potential part of the present invention, the signal generating circuit responds to the blowout of the fuse by connecting the thermoswitch to the secondary side of the insulating transformer and providing the fuse on the primary side. Since the insulating transformer is provided, the high potential portion and the signal generating circuit are insulated from each other, so that the conventional photocoupler and its driving power supply are not required. Therefore, compared to the conventional example, the number of parts is small, the manufacturing is simple, the cost is high, and the reliability is high. Moreover, since the secondary side of the insulating transformer is plural, the temperature abnormality of the high potential parts can be prevented. There is an effect that it becomes possible to detect.

[Brief description of drawings]

FIG. 1 is an illustration of an embodiment of the present invention, and FIG. 2 is an illustration of a conventional example. 1 ... Insulation transformer, 2 ... Thermo switch, 3 ... Power supply, 4 ... Fuse, 5 ... Signal generation circuit, 6 ... High potential part

Claims (1)

[Scope of utility model registration request] 1. An insulating transformer, a thermoswitch connected to the secondary side of the insulating transformer to turn on when an abnormal temperature rise of a high potential part is detected, and a power source connected to the primary side of the insulating transformer. And a fuse that is connected in series to the primary side of the isolation transformer and blows in the short-circuit state of the secondary side due to the ON operation of the thermoswitch, and an abnormal signal is generated in response to the blow of the fuse. A temperature abnormality detection circuit for a high potential part including a signal generation circuit.