Emergency inverter operation device for electric vehicle and method therefor

Abstract

The present invention provides an emergency inverter operation device for an electric vehicle which can compensate for the imbalance of a 3-phase current caused by an unbalanced voltage of a direct current link terminal, and produce a new reference voltage obtained by adding a correction voltage to compensate for the variation of the direct current link terminal, and a method therefor. An emergency inverter operation device according to the present invention includes: a serially connected upper and lower terminal direct voltage link; a 3-phase inverter for converting a direct link voltage applied to the upper and lower terminal direct voltage link into a 3-phase alternating voltage; a 3-phase motor driven by the 3-phase alternating voltage outputted from the 3-phase inverter; an emergency connection part for connecting each phase input terminal of the 3-phase motor to the middle point of the upper and lower terminal direct voltage link; a voltage detection part for detecting the voltage of the upper and lower terminal direct voltage link; an imbalance compensation part for receiving the output of the voltage detection part, the 3-phase reference voltage, and the direct link reference voltage so as to produce a phase voltage deviation compensated reference value obtained by compensating for a phase voltage deviation; and a pulse-width modulation control part for producing a pulse-width modulation control signal by means of the phase voltage deviation compensated reference value.

Description

technical field [0001] The present invention relates to an inverter for an electric vehicle, and relates to an emergency operation device and an emergency operation device thereof in the case of a failure of a bridge arm of one phase during the operation of a three-phase motor used in an electric vehicle through a three-phase inverter. method. Background technique [0002] An electric vehicle uses a three-phase motor to generate sufficient power, and the three-phase motor is operated by a three-phase inverter. On the other hand, since electric vehicles run on roads, continuous driving is required even if a part of the three-phase inverter fails. [0003] For this, as figure 1 As shown, in addition to configuring a three-phase inverter 120 between the DC link capacitors 110, C1, C2 and the three-phase motor 140 at the upper and lower ends, the present invention includes an emergency connection part 130, and the above-mentioned emergency connection part 130 is used The inte...

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Problems solved by technology

[0022] However, in the prior art as described above, according to the switching state of the three-phase inverter 120, the line voltage will be the voltage of the upper and lower capacitors, such as upper or lower capacitors, whose line voltage has the possibility of receiving current from one capacitor. Form, so the imbalance of the voltage of each capacitor not only makes the magnitude of the line voltage different, but also makes the phase different, so there is a problem of performance degradation caused by this

[0023] That is, in the case where the voltages of the upper and lower capacitors are the same, as Figure 5 As shown on the left in , with mutually orthogonal voltage vectors, in the case of different voltages, such as Figure 5 As shown on the right side of , the magnitude and phase are both distorted, which will lead to performance degradation based on the difference between the command value voltage and the actual value voltage

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