Method of regulating a voltage inverter operating in quasi-reson

Details Method of regulating a voltage inverter operating in quasi-reson Method of regulating a voltage inverter operating in quasi-reson

1994-02-28

1995-07-11

Dougherty, Thomas M.

Electric power conversion systems

Current conversion

With condition responsive means to control the output...

363132, H02M 75387

Patent

active

054326940

DESCRIPTION:

BRIEF SUMMARY
Method of regulating a voltage inverter operating in quasi-resonance.
The present invention relates to voltage inverters operating in quasi-resonance.
These inverters are supplied with power by a DC voltage source, they include a bridge, single-phase or multi-phase, with controlled components operating in turned off-saturated mode; these inverters include an oscillating circuit arranged on the same side as the DC voltage power supply; it consists of an inductor in series with the DC voltage source, and of a capacitor connected in parallel with the bridge with controlled components.
The starting and the maintenance of the oscillations of the oscillating circuit on the DC voltage source side are performed by successive short-circuits of the capacitor, on the zero-crossings of the voltage at its terminals, that is to say at the resonance frequency of the oscillating circuit. Hence, the energy necessary to sustain the oscillations is regularly stored in the inductor of the oscillating circuit. The short-circuits are provided by the simultaneous closing of the two switches of one of the arms of the bridge.
Moreover, according to the principle of quasi-resonance, any switching of any one of the controlled components of the bridge must substantially coincide with the zero-crossing of the voltage at the terminals of the capacitor of the oscillating circuit.
The conventional regulation methods adapted to inverters operating in quasi-resonance are synchronized to the resonance frequency. This is the case for the modulation known as "Sigma-Delta"; this technique consists in converting a reference signal into a two-level signal according to a synchronization frequency. In effect, the output is compared with a reference and the error obtained is passed through an integrator. The output of the integrator is then quantized into two possible levels, positive or negative, depending on its polarity. The output of the comparator is applied to a logic circuit, sampled at the resonance frequency of the oscillating circuit, in order to produce the control pulses for the voltage inverter. In any event, this method does not take account of the nature of the poles of the charge, or of the characteristics of the model of the inverter operating in the quasi-resonance mode. The only degree of freedom for achieving the desired performance is to increase the sampling frequency, and thus the resonance frequency of the oscillating circuit, which significantly increases the losses by switching.
It results therefrom that the performance of these voltage inverters operating in quasi-resonance mode is limited.
Thus, the object of the present invention is to supply a voltage inverter operating in quasi-resonance mode, in which the losses by switching are significantly reduced, and which can be subject to high-performance digital regulation in order to control the various loads of the inverter.
To that end, the subject of the invention is a method of regulating a voltage inverter operating in quasi-resonance, including an inverter bridge with controlled components operating in turned off-saturated mode, and an oscillating circuit arranged on the DC voltage side and consisting of an inductor in series with the DC voltage source, and of a capacitor connected in parallel with the bridge with controlled components, characterized in that pulse-width modulation regulation is carried out, in which the sampling period is very much greater than and of the order of about ten or more times the resonance period of the oscillating circuit.
The invention makes it possible to separate the function of maintaining, by analogue means, the short circuits, at high frequency, which are necessary for sustaining the oscillation, from the regulation function proper. This makes it possible to use digital regulators operating at lower frequencies than the resonance frequency, and which can take into account the characteristics of the load. The invention thus makes it possible to associate the advantages characteristic of high-frequency resonance, namely the reduction i

REFERENCES:
Patent Abstracts of Japan, vol. 14, No. 125 Mar. 8, 1990 & JP-1,318,547, (NEC) Dec. 25, 1989.
Zero-Switching-Loss inverters for High-Power Applications; Divan & Skibinsky, IEEE Transactions on Application and Industry, vol. 25, No. 4, Aug. 1989, New York US, pp. 634-643.
Pulse Width Modulation with Resonant DC Link Converters; Venkataramanan & Divan; Conf. Rec IEEE Industry Application Society Annual Meeting, vol. II, Oct. 1990, Seattle Washington US, pp. 984-990.
A Synchronized Resonant DC Link Converter for Soft-Switching PWM; Tenti, Divan & Tiogo; Conf Rec IEEE Industry Applications Society Annual Meeting, vol. I. Oct. 1989, San Diego, Calif. US, PP. 1037-1044.
Delta Modulation Strategies for Resonant Link Inverters, Kheraluwala & Divan; PESC '87 Record 1987, Blacksburg, Va US, pp. 271-278.

Affiliated with

Also associated with

Rating

Method of regulating a voltage inverter operating in quasi-reson does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method of regulating a voltage inverter operating in quasi-reson, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of regulating a voltage inverter operating in quasi-reson will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-508107