Voltage Feedforward Control Research Articles

A space vector modulated CSI-based AC drive for multimotor applications

A space vector controlled channel state information (CSI) drive for multimotor applications is investigated. The multimotor operation of the drive is achieved by integrating the proposed active damping control, inverter-side DC link voltage feedforward control and pulse width modulation (PWM) index control into the conventional V/f control. The main function of the active damping control is to suppress possible LC resonances caused by the inverter filter capacitor and motor inductances. This function is essential in achieving stable operation of the drive, especially in the multimotor drive where multiple LC resonant modes exist. An additional advantage provided by the active damping control is that it makes the control system less sensitive to motor parameters. The inverter-side DC link voltage feedforward control and the adjustable PWM modulation index control are developed to improve the dynamic performance of the drive system. In addition, the proposed space vector PWM pattern features a low switching frequency (500 Hz), which makes the proposed drive system suitable for high power applications. The system stability is investigated by means of eigenvalue analysis. The theoretic analysis is verified by experiments on a digital signal processing (DSP) controlled CSI multimotor drive.

Open-loop peak voltage feedforward control of PWM buck converter

DC and small-signal analyses are given for an open-loop buck pulse-width modulated (PWM) DC-DC converter with peak-voltage-modulation (PVM) feedforward control. A DC model is used to derive the DC input-to-output voltage transfer function taking into account parasitic components, such as the MOSFET on-resistance, diode forward resistance, and diode offset voltage. A small-signal model is used to derive the audio susceptibility and the input impedance. It is shown that ideally the audio susceptibility is zero and the input impedance is frequency independent and negative for the buck converter with PVM feedforward control.

Dynamic performance of PWM DC-DC boost converter with input voltage feedforward control

Small-signal characteristics are studied for a pulse-width modulated (PWM) boost converter with input voltage feedforward control. The characteristics are valid for the continuous conduction mode (CCM). A small-signal circuit model is used to derive the input-to-output voltage transfer function (audio-susceptibility), the input impedance, and the output impedance. A response of the output voltage to a step change in the input voltage is also computed. The measured Bode plots of the input-to-output voltage transfer function agreed with that predicted theoretically. It is shown that the feedforward control may reduce the magnitude of the input-to-output voltage transfer function by 40 dB. The input resistance of the converter with feedforward control is negative at low frequencies. The output impedance is not affected by feedforward control.

Vibration Suppression of a Rotary Compressor for a Room Air Conditioner by using a Feedforward Voltage Control. 1st Report. Basic Study of the Control Effects by Computer Simulation.

Vibration Suppression of a Rotary Compressor for a Room Air Conditioner by using a Feedforward Voltage Control. 1st Report. Basic Study of the Control Effects by Computer Simulation.

Simulation and control of a 20-kHz spacecraft power system

A detailed computer representation of four Mapham inverters connected in a series-parallel arrangement has been implemented. System performance is illustrated by computer traces for the four Mapham inverters connected to a Litz cable with parallel resistance and DC receiver loads at the receiving end of the transmission cable. Methods of voltage control and load sharing between the inverters are demonstrated. The computer representation is used to design and demonstrate the advantages of a feedforward voltage-control strategy. It is shown that with a computer simulation of this type, the performance and control of spacecraft power systems can be investigated with relative ease and facility. >