Direct three phase parallel resonant inverter for reactive gas generator applications

Patent metadata

Field	Value
Publication number	US-9648716-B2
Application number	US-201514843412-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 2, 2015
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

A power system for a reactive gas generator can include a direct three phase inverter. A resonant tank can further be included to receive a square wave output of the direct three phase inverter and provide a sine wave output. The power system can include an inverter controller that turns on and off selected switches of the direct three phase inverter based on states of the three phases of a three phase AC power supply, where a switch is turned on with an adaptive ON time and a modulated OFF time depending on a desired output power.

First claim

What is claimed is:

1. A power system comprising:
a direct three phase inverter having a first phase input line, a second phase input line, and a third phase input line for receiving a three phase AC input;
a resonant tank receiving an output of the direct three phase inverter; and
an inverter controller connected to the first phase input line, the second phase input line, and the third phase input line for receiving the three phase AC input;
wherein the output of the direct three phase inverter is provided to the resonant tank via a first output line and a second output line, wherein the direct three phase inverter comprises six uni-directional switches, one uni-directional switch connecting the first phase input line to the first output line, one uni-directional switch connecting the first phase input line to the second output line, one uni-directional switch connecting the second phase input line to the first output line, one uni-directional switch connecting the second phase input line to the second output line, one uni-directional switch connecting the third phase input line to the first output line, and one uni-directional switch connecting the third phase input line to the second output line;
wherein the inverter controller has a first signal line coupled to the first uni-directional switch to control the first uni-directional switch, a second signal line coupled to the second uni-directional switch to control the second uni-directional switch, a third signal line coupled to the third uni-directional switch to control the third uni-directional switch, a fourth signal line coupled to the fourth uni-directional switch to control the fourth uni-directional switch, a fifth signal line coupled to the fifth uni-directional switch to control the fifth uni-directional switch, and a sixth signal line coupled to the sixth uni-directional switch to control the sixth uni-directional switch,
wherein the inverter controller comprises logic that:
in response to an indication of a first phase of the three phase AC input being equal to a third phase of the three phase AC input, maintains the first uni-directional switch and the fourth uni-directional switch in an OFF state and alternates between turning on and off both the second uni-directional switch and the third uni-directional switch and turning on and off both the fifth uni-directional switch and the sixth uni-directional switch;
in response to an indication of the first phase being equal to a second phase of the three phase AC input, maintains the third uni-directional switch and the sixth uni-directional switch in the OFF state and alternates between turning on and off both the first uni-directional switch and the second uni-directional switch and turning on and off both the fourth uni-directional switch and the fifth uni-directional switch; and

in response to an indication of the second phase being equal to the third phase, maintains the second uni-directional switch and the fourth uni-directional switch in the OFF state and alternates between turning on and off both the first uni-directional switch and the third uni-directional switch and turning on and off both the fourth uni-directional switch and the sixth uni-directional switch.

2. The power system of claim 1 , wherein each of the six uni-directional switches comprises a power transistor and four diodes.

3. The power system of claim 2 , wherein the power transistor is a metal-oxide-semiconductor field-effect transistor, bipolar junction transistor, insulated-gate bipolar transistor or silicon carbide transistor.

4. The power system of claim 1 , wherein each of the six uni-directional switches comprises two metal-oxide-semiconductor field-effect transistors (MOSFETs), the two MOSFETs being coupled at their gates and their sources.

5. The power system of claim 1 , wherein the inverter controller is coupled to the resonant tank to receive a sensed output current and a sensed output power from the resonant tank, wherein the inverter controller further comprises logic that, while providing an adaptive ON time, modulates an amount of OFF time for each of the first, second, third, fourth, fifth, and sixth uni-directional switches based on the sensed output current and the sensed output power.

6. A power system comprising:
a direct three phase inverter having a first phase input line, a second phase input line, and a third phase input line for receiving a three phase AC input; and
an inverter controller connected to the first phase input line, the second phase input line, and the third phase input line for receiving the three phase AC input and controlling the direct three phase inverter based on states of the three phase AC input,
wherein the inverter controller comprises:
a phase detector;
a gate driver comprising gate driving logics and an adaptive one-shot gate driving circuit; and
a current/power regulator and a voltage controlled oscillator, wherein the voltage controlled oscillator outputs a signal having a frequency based on a sensed power and sensed current received via the current/power regulator, wherein the adaptive one-shot gate driving circuit receives the signal having the frequency and generates a driving signal that modulates a length of OFF time while providing an adaptive ON time.

7. The power system of claim 6 , wherein the phase detector receives the three phase AC input and outputs corresponding voltages representative of each signal of the three phase AC input,
wherein the gate driving logics comprises logic that receives the corresponding voltages representative of each signal of the three phase AC input and turns on particular switches of the direct three phase inverter based on a phase state of the signals of the three phase AC input.

8. The power system of claim 7 , wherein the direct three phase inverter comprises six uni-directional switches, one uni-directional switch connecting the first phase input line to a first output line of the direct three phase inverter when turned on by the inverter controller, one uni-directional switch connecting the first phase input line to a second output line of the direct three phase inverter when turned on by the inverter controller, one uni-directional switch connecting the second phase input line to the first output line when turned on by the inverter controller, one uni-directional switch connecting the second phase input line to the second output line when turned on by the inverter controller, one uni-directional switch connecting the third phase input line to the first output line when turned on by the inverter controller, and one uni-directional switch connecting the third phase input line to the second output line when turned on by the inverter controller.

9. The power system of claim 8 , wherein the logic that receives the corresponding voltages representative of each signal of the three phase AC input and turns on particular switches of the direct three phase inverter based on a phase state of the signals of the three phase AC input comprises logic that:
in response to an indication of a first phase of the three phase AC input being equal to a third phase of the three phase AC input, maintains the first uni-directional switch and the fourth uni-directional switch in an OFF state and alternates between turning on and off both the second uni-directional switch and the third uni-directional switch and turning on and off both the fifth uni-directional switch and the sixth uni-directional switch;
in response to an indication of the first phase being equal to a second phase of the three phase AC input, maintains the third uni-directional switch and the sixth uni-directional switch in the OFF state and alternates between turning on and off both the first uni-directional

Assignees

• Mks Instr Inc

Inventors

• Tran Ken
• Tian Feng

Classifications

• H05H1/24 Primary

  Generating plasma {(nuclear fusion reactors G21B1/00; gas-filled discharge reactors H01J37/32)} · CPC title

• H01J37/32082 Primary

  Radio frequency generated discharge (H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence) · CPC title

• H02M7/537

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• H02M5/297

  for conversion of frequency · CPC title

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title