JPS6184697U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a specific example of a drive system showing the driving operation method of a motor using a current source inverter to which the present invention is applied, and Fig. 2 is a simplified block configuration of the motor system including a DC reactor. Figure 3 is a circuit diagram showing the specific configuration of the voltage control amplifier and current control amplifier, and Figure 4 is the circuit diagram shown in Figure 1 (Figure 2).
A block configuration diagram showing the transfer function of the drive system in Fig.
Figure 5 is a root locus diagram that derives the roots from the characteristic equation of the transfer function and shows how the root locus changes depending on the gain on the complex plane, and Figure 6 shows the gain according to the present invention. An example showing a specific example of adjustment, Fig. 7 is a primary current waveform diagram of any phase of the induction motor, Fig. 8 is a block diagram of the transfer function when Fig. 4 is modified, and Fig. 9 is a diagram of the block diagram of the transfer function. FIG. 2 is a block configuration diagram of the transfer function of the entire control system when FIG. 2 is embodied. CV is a forward conversion section, IV is an inverse conversion section, Ld is a DC reactor, OP ₁ is a voltage control amplifier, OP ₂
is the current control amplifier, A is the voltage detection circuit, and B is the V
/F conversion circuit, C is a phase shift circuit, RC is a ring counter, IM is an induction motor, 1 and 3 are multiplication circuits,
2 is a division circuit.

Claims (1)

[Scope of utility model registration request] A voltage control loop that amplifies the deviation between the voltage setting signal and the voltage detection signal to provide a current command, and controls the gate of the forward conversion section based on the signal that amplifies the deviation between the current command signal and the current detection signal. and a frequency control loop that controls the output frequency by controlling the gate of the inverse converter based on the voltage setting signal, and drives the load motor with a current source inverter that does not feed back the speed detection signal. , a divider takes the inverter's operating frequency ω ₀ or the reciprocal of the inverter's AC output voltage Ea, and the output of this divider is multiplied by the output of the voltage control amplifier of the voltage control loop to obtain the current. 1. A control device for a current source inverter, comprising a multiplier that provides a current command to a control loop and makes the overall gain of an inverter control system substantially constant.