Auxiliary quasi-resonant dc tank electrical power converter
First Claim
1. An auxiliary quasi-resonant dc tank converter, comprising:
- an ac power supply and an ac bus;
a dc power supply for providing dc current to a dc bus;
an inverter having at least one phase leg connected to said ac bus and connected across said dc bus, said inverter having at least one main switching device per phase leg;
a quasi-resonant dc tank circuit coupled in parallel with said dc power supply for generating a quasi-resonant voltage across said dc bus, said quasi-resonant dc tank circuit including,an upper resonant capacitor and a lower resonant capacitor connected in series as a resonant leg,a first dc tank capacitor, a second dc tank capacitor, and a third dc tank capacitor connected in series as a tank leg,an auxiliary quasi-resonant circuit coupled across the junction of said upper and lower resonant capacitors, the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, said lower resonant capacitor being coupled across said dc bus, said resonant leg being coupled across said tank leg, anda first clamping means coupled across said upper resonant capacitor,said auxiliary quasi-resonant dc tank converter further comprising a charge circuit coupled across the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors,wherein said charge circuit further comprises a transformer coupled across said resonant inductor feeding a diode bridge to charge said second tank capacitor.
1 Assignment
0 Petitions
Accused Products
Abstract
An auxiliary quasi-resonant dc tank (AQRDCT) power converter with fast current charging, voltage balancing (or charging), and voltage clamping circuits is provided for achieving soft-switched power conversion. The present invention is an improvement of the invention taught in U.S. Pat. No. 6,111,770, herein incorporated by reference. The present invention provides faster current charging to the resonant inductor, thus minimizing delay time of the pulse width modulation (PWM) due to the soft-switching process. The new AQRDCT converter includes three tank capacitors or power supplies to achieve the faster current charging and minimize the soft-switching time delay. The new AQRDCT converter further includes a voltage balancing circuit to charge and discharge the three tank capacitors so that additional isolated power supplies from the utility line are not needed. A voltage clamping circuit is also included for clamping voltage surge due to the reverse recovery of diodes.
-
Citations
4 Claims
-
1. An auxiliary quasi-resonant dc tank converter, comprising:
-
an ac power supply and an ac bus; a dc power supply for providing dc current to a dc bus; an inverter having at least one phase leg connected to said ac bus and connected across said dc bus, said inverter having at least one main switching device per phase leg; a quasi-resonant dc tank circuit coupled in parallel with said dc power supply for generating a quasi-resonant voltage across said dc bus, said quasi-resonant dc tank circuit including, an upper resonant capacitor and a lower resonant capacitor connected in series as a resonant leg, a first dc tank capacitor, a second dc tank capacitor, and a third dc tank capacitor connected in series as a tank leg, an auxiliary quasi-resonant circuit coupled across the junction of said upper and lower resonant capacitors, the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, said lower resonant capacitor being coupled across said dc bus, said resonant leg being coupled across said tank leg, and a first clamping means coupled across said upper resonant capacitor, said auxiliary quasi-resonant dc tank converter further comprising a charge circuit coupled across the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, wherein said charge circuit further comprises a transformer coupled across said resonant inductor feeding a diode bridge to charge said second tank capacitor. - View Dependent Claims (2)
-
-
3. An auxiliary quasi-resonant dc tank converter, comprising:
-
an ac power supply and an ac bus;
a dc power supply for providing dc current to a dc bus;an inverter having at least one phase leg connected to said ac bus and connected across said dc bus, said inverter having at least one main switching device per phase leg; a quasi-resonant dc tank circuit coupled in parallel with said dc power supply for generating a quasi-resonant voltage across said dc bus, said quasi-resonant dc tank circuit including, an upper resonant capacitor and a lower resonant capacitor connected in series as a resonant leg, a first dc tank capacitor, a second dc tank capacitor, and a third dc tank capacitor connected in series as a tank leg, an auxiliary quasi-resonant circuit coupled across the junction of said upper and lower resonant capacitors, the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, said lower resonant capacitor being coupled across said dc bus, said resonant leg being coupled across said tank leg, a first clamping means coupled across said upper resonant capacitor, said converter further comprising a charge circuit coupled across the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, wherein said charge circuit further comprises an outside dc power supply to maintain voltage in said second tank capacitor.
-
-
4. An auxiliary quasi-resonant dc tank converter, comprising:
-
an ac power supply and an ac bus; a dc power supply for providing dc current to a dc bus; an inverter having at least one phase leg connected to said ac bus and connected across said dc bus, said inverter having at least one main switching device per phase leg; a quasi-resonant dc tank circuit coupled in parallel with said dc power supply for generating a quasi-resonant voltage across said dc bus, said quasi-resonant dc tank circuit including, an upper resonant capacitor and a lower resonant capacitor connected in series as a resonant leg, a first dc tank capacitor, a second dc tank capacitor, and a third dc tank capacitor connected in series as a tank leg, an auxiliary quasi-resonant circuit coupled across the junction of said upper and lower resonant capacitors, the junction of said first and second dc tank capacitors and the junction of said second and third dc tank capacitors, said lower resonant capacitor being coupled across said dc bus, said resonant leg being coupled across said tank leg, and a first clamping means coupled across said upper resonant capacitor, wherein each phase leg of said inverter has its own resonant dc tank circuit and is connected to each other through magnetic coupling, and further the tank leg of the quasi-resonant dc tank circuit of each phase leg is coupled to each other.
-
Specification