JPH05336758A - Regenerative resistance protecting device for inverter - Google Patents

Abstract

PURPOSE:To avoid a burning accident of a regenerative resistor even if a power semiconductor is troubled by providing a trouble deciding circuit for comparing a gate signal to the semiconductor with a conduction signal by a current detector to control start of conduction of a thyristor switch. CONSTITUTION:When a resistance regeneration is normally conducted, a power semiconductor 12 operates in response to a gate signal from a gate signal generator 11. If a current flows from the generator 11 to the resistor even if the gate signal is not output from the generator 11, a power semiconductor trouble deciding circuit 14 decides a trouble of the semiconductor, and outputs a trigger signal to a thyristor switch 15. When the switch 15 is closed, a melting current to a fuse 16 flows to melt the fuse 16, thereby breaking a regenerative resistance circuit. Thus, a burning accident of the resistor can be not only avoided, but also the resistance circuit is disconnected to operate at the time of an emergency by utilizing a power running circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter regenerative resistance protection device.

[0002]

2. Description of the Related Art Conventionally, in a resistance braking circuit driven by an inverter of a three-phase AC motor, when a power semiconductor, which is a switch of a regenerative resistance circuit, fails, the regenerative resistance circuit is always energized, and the regenerative resistor burns out. Leading to an accident.

Further, in the case of an in-vehicle inverter, there are problems that the engine starting motor cannot be driven and the battery of the inverter driving power source is discharged.

[0004]

SUMMARY OF THE INVENTION The present invention provides an inverter regenerative resistor capable of avoiding a burnout accident of the regenerative resistor against a fault of a power semiconductor and facilitating disconnection of the regenerative braking circuit after the fault. It is to provide a protection device.

[0005]

According to the present invention, a positive / negative DC bus for supplying a DC power source to an inverter circuit, a regenerative resistor connected between the positive / negative DC bus and absorbing regenerative power generated in the inverter circuit, and A power semiconductor connected in series with the regenerative resistor to control the start of energization to the regenerative resistor by a gate signal, and a current detector connected in series with the power semiconductor and the regenerative resistor to detect a current flowing through the regenerative resistor, A fuse connected in series with this current detector, regenerative resistor and power semiconductor to cut off circuit continuity when fused, and a series circuit consisting of the current detector, regenerative resistor and power semiconductor, connected in parallel, and regenerated. The thyristor switch that bypasses the resistor and conducts is compared with the gate signal to the power semiconductor and the energization signal from the current detector to compare the thyristor switch. An inverter regenerative resistor protecting apparatus comprising; and a failure determination circuit for controlling the energization start of pitch.

[0006]

In the inverter regenerative resistance protection device of the present invention, the regenerative resistor is connected between the positive and negative DC bus lines that supply the DC power to the inverter circuit, absorbs the regenerative power generated in the inverter circuit, and connects in series with the regenerative resistor. A power semiconductor is connected to control the start of energization to the regenerative resistor with a gate signal, and a current detector is connected in series with the power semiconductor and the regenerative resistor to detect the current flowing through the regenerative resistor. A fuse is connected in series with the resistor and the power semiconductor to cut off circuit continuity when the fuse is blown, and a thyristor switch is connected in parallel to the series circuit consisting of the current detector and the regenerative resistor and the power semiconductor. It conducts by bypassing and compares the gate signal to the power semiconductor and the energization signal from the current detector to control the energization start of the thyristor switch.

[0007]

EXAMPLE An example of the present invention will be described below. In FIG. 1, P and N are positive and negative DC bus lines that supply DC power to the inverter circuit 2, 5 is a regenerative resistor that is connected between the positive and negative DC bus lines P and N, and absorbs regenerative power generated in the inverter circuit 2, and 6 is A power semiconductor that is connected in series with the regenerative resistor 5 and controls the start of energization to the regenerative resistor 5 by a gate signal.
Is a current detector connected in series with the power semiconductor 6 and the regenerative resistor 5 to detect the current flowing through the regenerative resistor 5, and 7 is connected in series with the current detector 9 and the regenerative resistor 5 and the power semiconductor 6 and blown A fuse that sometimes interrupts circuit continuity, 8 is connected in parallel to a series circuit composed of a current detector 9 and a regenerative resistor 5 and a power semiconductor 6, and a thyristor switch that bypasses the regenerative resistor 5 and conducts electricity is a thyristor switch 10. This is a failure determination circuit that controls the start of energization of the thyristor switch 8 by comparing the gate signal to the power semiconductor 6 and the energization signal from the current detector 9. A fuse 7 for breaking and breaking the resistance circuit, and a regenerative resistor 5 for supplying a current to the fuse 7.
Also, a thyristor switch 8 connected in parallel with the power semiconductor 6, a current detector 9 for detecting a current between the power conductor 6 and the regenerative resistor 5, a gate signal to the power semiconductor 6, and a current detector. 9 is an inverter regenerative resistance protection device composed of a circuit for outputting a trigger signal to the thyristor switch 8 in comparison with the energization signal from 9.

Then, even if the gate signal to the power semiconductor 6 is turned off, if it is detected that a current is flowing through the regenerative resistance circuit, it is determined that the power semiconductor 6 is out of order. Then, the thyristor switch 8 of the circuit that bypasses the regenerative resistor 5 is turned on, and a fusing current is passed through the fuse 7 to interrupt the regenerative resistor circuit.

FIG. 1 shows a circuit configuration of this embodiment. A fuse 7 for cutting off a regenerative resistance circuit from a conventional voltage type inverter resistance regenerative circuit including a three-phase AC motor 1, an inverter unit 2, a capacitor 3, a DC power source or converter unit 4, a regenerative resistor 5, and a power semiconductor 6. , A thyristor switch 8 connected in parallel with the regenerative resistor 5 and the power semiconductor 6 in order to flow a fusing current through the fuse 7, a current detector 9 for detecting energization of the regenerative resistor 5, and a power semiconductor failure determination circuit 10. It is composed of a circuit added with.

FIG. 2 shows a block diagram of this embodiment. When resistance regeneration is normally performed, the power semiconductor 12 operates according to the gate signal from the gate signal generation circuit 11. If a current flows through the regenerative resistor in the current detector 13 even though no gate signal is generated from the gate signal generation circuit 11, the power semiconductor failure determination circuit 14 determines that the power semiconductor has failed, and the thyristor A trigger signal is output to the switch 15. Thyristor switch 15 is ON
Then, a fusing current flows to the fuse 16 and the fuse 16
Melts and shuts off the regenerative resistor circuit.

[0011]

According to the present invention, even when the power semiconductor fails, the regenerative resistor burnout accident can be avoided, and the regenerative resistor circuit is separated to make use of the power running circuit for emergency operation. In addition, it is possible to avoid the discharge of the battery power source, and it can be realized in a small space.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an inverter regenerative resistance protection device showing an embodiment of the present invention.

FIG. 2 is a block diagram illustrating the operation of FIG.

[Explanation of symbols]

 5 Regenerative resistor 6 Power semiconductor 7 Fuse 8 Thyristor switch 9 Current detector 10 Failure judgment circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H02P 7/63 R 9178-5H

Claims (1)

[Claims] 1. A positive / negative DC bus for supplying a DC power source to an inverter circuit, a regenerative resistor connected between the positive / negative DC bus for absorbing regenerative power generated in the inverter circuit, and connected in series with the regenerative resistor. A power semiconductor for controlling the start of energization to the regenerative resistor by a gate signal,
A current detector that is connected in series with the power semiconductor and the regenerative resistor to detect a current flowing through the regenerative resistor;
A fuse that is connected in series with the current detector, the regenerative resistor, and the power semiconductor to cut off circuit continuity when the fuse is blown, and in parallel with a series circuit including the current detector, the regenerative resistor, and the power semiconductor. A thyristor switch that is connected to and that conducts by bypassing the regenerative resistor, and compares the gate signal to the power semiconductor and the energization signal by the current detector to control energization start of the thyristor switch. An inverter regenerative resistance protection device comprising a judgment circuit.