Inverter control device and power conversion device

Abstract

The invention discloses a direct current converter control device and a power conversion device. The DC voltage value from the DC voltage detection unit (201) is directly input to the voltage correction unit (202) without passing through a compensator or a filter. Therefore, even when there is a sudden voltage change such as an instantaneous power failure, an instantaneous voltage drop, or recovery from an instantaneous voltage drop, the voltage correction unit (202) can perform high-speed correction processing for the sudden change. Since the connection part resonance compensation amount of the limiting part (212) is limited within a certain range, it is possible to prevent excessive fluctuations in the connection part resonance compensation amount when the voltage suddenly changes. Because the connection part resonance compensation amount limited by the limiting part (212) within a certain range is input into the compensator (206) suitable for the control band in the control calculation part (204-208), it is not necessary to perform a high-speed response beyond the need, and the control Stablize.

Description

Technical field [0001] The invention relates to a technology for controlling a direct-to-ac converter that drives an alternating-current motor. Background technique [0002] Generally speaking, in a voltage-type DC-AC converter having a filter capacitor in the DC connection portion, a constant output voltage control is performed to suppress the fluctuation of the output voltage due to the fluctuation of the DC input voltage. figure 1 The schematic configuration of a conventional DC-AC converter that performs this constant output voltage control is shown. In addition, figure 1 In the control system, the output current detection unit 160 is arranged between the DC / AC conversion unit 140 and the motor 150. However, it is sufficient as long as it can detect the current output to the motor 150. For example, It is a structure in which a shunt resistor is arranged to detect the current in the DC connection part. [0003] figure 1 The DC / AC conversion device in includes a DC / AC conversion...

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Problems solved by technology

[0041] However, [Patent Document 2]'s figure 1 In the control method shown, the DC voltage value of the input voltage calculation and correction circuit 11 is delayed due to a delay 14 as much as the time constant. , from the start of the instantaneous voltage drop to the completion of recovery, etc.), the response of the voltage calculation correction circuit 11 is delayed, which has a bad influence on the control

In particular, when the input voltage of the direct-to-alternating converter 4 suddenly increases, the output voltage increases due to the response delay of the voltage calculation correction circuit 11, and the output voltage of the direct-to-AC converter 4 increases due to the resonance suppression control of the connection part. , resulting in an overcurrent

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