Two-source series inverter
View Patent ↗Systems and methods are disclosed for a two-source series inverter. The systems and methods combine operation of a first voltage source and a second voltage source in series powering a novel voltage combining arrangement and a conventional inverter via a switch configuration to power a load. The switch configuration is controlled by a plurality of control signals generated by a controller based on a variety of control modes, and feedback signals.
1. A two-source series inverter system, the system comprising:
a first voltage source;
a second voltage source;
an inverter having a first DC input, a second DC input, AC outputs, and first control inputs, wherein the AC outputs are configured to be coupled to a load, the load comprising an AC electric machine that provides power to a powertrain of a vehicle;
a voltage combiner having a second control input, the voltage combiner being connected to the first DC input and the second DC input, and coupled to the first voltage source and the second voltage source; and
a controller coupled to the first control inputs and the second control input, the controller being configured to receive first feedback signals and second feedback signals from the inverter and the voltage combiner respectively, and configured to control current flow through the voltage combiner and the inverter, wherein:
the controller is configured to operate the inverter and the voltage combiner to control flow of a recharging current from the inverter through the voltage combiner to the first voltage source;
a first electrical current flows from the first voltage source to the inverter through the voltage combiner; and
a second electrical current flows from the second voltage source to the inverter through the voltage combiner.
2. The system according to claim 1 , wherein the inverter comprises a single source multi-phase inverter.
3. The system according to claim 1 , wherein the voltage combiner further comprises:
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source, and the second DC input of the inverter;
a fifth node coupled to the first DC input of the inverter;
a first capacitor connected between the first node and the second node;
a second capacitor connected between the second node and the fourth node;
a first diode connected between the second node and the third node;
a second diode connected between the second node and the fifth node;
a switch connected between the first node and the fifth node; and
a third diode connected between the first node and the fifth node.
4. The system according to claim 1 , wherein the voltage combiner further comprises:
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source, and coupled to the second DC input of the inverter;
a fifth node coupled the first DC input of the inverter;
a first capacitor connected between the first node and the second node;
a second capacitor connected between the second node and the fourth node;
a first diode connected between the second node and the third node;
a second diode connected between the second node and the fifth node;
a switch connected between the first node and the fifth node; and
a plurality of diodes each connected between the first node and one of the AC outputs respectively.
5. The system according to claim 1 , wherein the voltage combiner further comprises:
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source, and coupled to the second DC input of the inverter;
a fifth node coupled the first DC input of the inverter;
a first capacitor connected between the first node and the second node;
a second capacitor connected between the second node and the fourth node;
a first diode connected between the second node and the third node;
a second diode connected between the second node and the fifth node;
switch connected between the first node and the fifth node;
a first connection between the first node and a first inverter diode in the inverter;
a second connection between the first node and a second inverter diode in the inverter; and
a third connection between the first node and a third inverter diode in the inverter.
6. The system according to claim 1 , wherein the controller is further configured to control duty cycles of:
the first control inputs; and
the second control input.
7. The system according to claim 1 , further comprising a multi-phase load coupled to the AC outputs.
8. The system according to claim 1 , wherein the voltage combiner further comprises a plurality of diodes configured to limit the direction of current flow.
9. The two-source series inverter system of claim 1 , wherein the voltage combiner comprises:
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source and the second DC input of the inverter;
a fifth node coupled to the first DC input of the inverter;
a first diode coupled between the second node and the third node, the first diode being configured to allow current flow from the third node to the second node; and
a switch coupled between the first node and the fifth node, wherein the first voltage source and the second voltage source are connected in series when the switch is turned on.
10. A two-source series inverter system, the system comprising:
a first voltage source;
a second voltage source;
an inverter having a first DC input, a second DC input, AC outputs, and first control inputs, wherein the AC outputs are configured to be coupled to a load;
a voltage combiner connected to the first DC input and the second DC input, wherein the voltage combiner comprises:
a second control input;
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source, and the second DC input of the inverter;
a fifth node coupled to the first DC input of the inverter;
a first capacitor connected between the first node and the second node;
a second capacitor connected between the second node and the fourth node;
a first diode connected between the second node and the third node;
a second diode connected between the second node and the fifth node;
a switch connected between the first node and the fifth node; and
a third diode connected between the first node and the fifth node; and
a controller coupled to the first control inputs and the second control input, the controller being configured to receive first feedback signals and second feedback signals from the inverter and the voltage combiner respectively, and configured to control current flow through the voltage combiner and the inverter.
11. A two-source series inverter system, the system comprising:
a first voltage source;
a second voltage source;
an inverter having a first DC input, a second DC input, AC outputs, and first control inputs, wherein the AC outputs are configured to be coupled to a load;
a voltage combiner connected to the first DC input and the second DC input, wherein the voltage combiner comprises:
a second control input;
a first node coupled to a first terminal of the first voltage source;
a second node coupled to a second terminal of the first voltage source;
a third node coupled to a first terminal of the second voltage source;
a fourth node coupled to a second terminal of the second voltage source, and coupled to the second DC input of the inverter;
a fifth node coupled the first DC input of the inverter;
a first capacitor connected between the first node and the second node;
a second capacitor connected between the second node and the fourth node;
a first diode connected between the second node and the third node;
a second diode connected between the second node and the fifth node;
a switch connected between the first node and the fifth node; and
a plurality of diodes each connected between the first node and one of the AC outputs respectively; and
a controller coupled to the first control inputs and the second control input, the controller being configured to receive first feedback signals and second feedback signals from the inverter and the voltage combiner respectively, and configured to control current flow through the voltage combiner and the inverter.
12. A two-source series inverter system, the system comprising:
a first voltage source;
a second voltage source;
an inverter having a first DC input, a second DC input, AC outputs, and first control inputs, wherein the AC outputs are configured to be coupled to a load;
a voltage combiner having a second control input, the voltage combiner being connected to the first DC input and the second DC input, and coupled to the first voltage source and the second voltage source, wherein the voltage combiner comprises:
a first node configured to be coupled to a first terminal of the first voltage source;
a second node configured to be coupled to a second terminal of the first voltage source;
a third node configured to be coupled to a first terminal of the second voltage source;
a fourth node configured to be coupled to a second terminal of the second voltage source and the second DC input of the inverter;
a fifth node configured to be coupled to the first DC input of the inverter;
a first diode coupled between the second node and the third node, the first diode being configured to allow current flow from the third node to the second node; and
a switch coupled between the first node and the fifth node, wherein the first voltage source and the second voltage source are connected in series when the switch is turned on; and
a controller coupled to the first control inputs and the second control input, the controller being configured to receive first feedback signals and second feedback signals from the inverter and the voltage combiner respectively, and configured to control current flow through the voltage combiner and the inverter, wherein:
a first electrical current flows from the first voltage source to the inverter through the voltage combiner; and
a second electrical current flows from the second voltage source to the inverter through the voltage combiner.