AC motor driving circuit and electric car driving circuit
View Patent ↗In an AC motor driving circuit, a current-type rectifier circuit having a filter circuit and first bidirectional switches bridge-connected to the filter circuit is provided in an output of an AC power supply. An AC motor is connected to an output of the rectifier circuit through a voltage-type inverter. One terminal of each of second bidirectional switches is connected to corresponding one of output terminals of the current-type rectifier circuit. The other terminals of the second bidirectional switches are collectively connected to one terminal of a series circuit having a DC power supply and a reactor. The other terminal of the series circuit is connected to one output terminal of the current-type rectifier circuit. With this configuration, a large capacitor for a DC link can be dispensed with, so that a reduction in circuit size and weight can be attained.
1. An AC motor driving circuit for driving a first AC motor from an AC power supply and a DC power supply, which is configured to feed and absorb electric power, through a voltage-type inverter, the AC motor driving circuit comprising:
a first rectifier circuit configured to perform power conversion between the AC power supply and the first AC motor, the first rectifier circuit comprising a filter circuit, and first switches, the filter circuit being connected to the AC power supply at an input of the first rectifier circuit, a first terminal of each of the first switches being bridge-connected to an output of the filter circuit in an upper or lower arm of the first rectifier circuit, a second terminal of each of the first switches being connected to an output terminal of the respective upper or lower arm of the first rectifier circuit, the respective output terminal being connected to the first AC motor through the voltage-type inverter; and
a second rectifier circuit configured to perform power conversion between the AC power supply and the DC power supply, the second rectifier circuit comprising the filter circuit in common with the first rectifier circuit, second switches and a series circuit, the series circuit including a reactor and the DC power supply, a first terminal of each of the second switches being connected to a junction between the output of the filter circuit and a corresponding one of the first switches in the first rectifier circuit, and a second terminal of each of the second switches being connected to a first terminal of the series circuit including the reactor and the DC power supply, and a second terminal of the series circuit being connected to one of the output terminals of the first rectifier circuit,
wherein each switch of the first switches and the second switches is a bidirectional switch or a unidirectional switch, and
the series circuit is configured such that the AC motor driving circuit performs both power conversion to the AC motor and charging of the DC power supply.
2. The AC motor driving circuit according to claim 1 , wherein the first switches are bidirectional switches.
3. The AC motor driving circuit according to claim 1 , wherein the second switches are bidirectional switches.
4. The AC motor driving circuit according to claim 1 , wherein the first switches are unidirectional switches having reverse blocking capabilities.
5. The AC motor driving circuit according to claim 1 , wherein the second switches are unidirectional switches having reverse blocking capabilities.
6. The AC motor driving circuit according to claim 1 , wherein electric power from the first AC motor is regenerated in the AC power supply through the first rectifier circuit.
7. The AC motor driving circuit according to claim 1 , wherein the DC power supply is charged with electric power regenerated from the first AC motor through the second rectifier circuit.
8. An electric car driving circuit comprising the AC motor driving circuit according to claim 1 , wherein the AC power supply is a second AC motor driven by an internal combustion engine.
9. An AC motor driving circuit for driving a first AC motor, comprising:
an AC power supply;
a DC power supply configured to feed and absorb electric power;
a voltage-type inverter configured to convert DC power to AC power;
a first rectifier circuit configured to perform power conversion between the AC power supply and the first AC motor, the first rectifier circuit comprising a filter circuit and first switches, the filter circuit being connected to the AC power supply at an input of the first rectifier circuit, a first terminal of each of the first switches being bridge-connected to an output of the filter circuit in an upper or lower arm of the first rectifier circuit, and a second terminal of each of the first switches being connected to an output terminal of the respective upper or lower arm of the first rectifier circuit, the respective output terminal being connected to the first AC motor through the voltage-type inverter; and
a second rectifier circuit configured to perform power conversion between the AC power supply and the DC power supply, the second rectifier circuit comprising the filter circuit in common with the first rectifier circuit, second switches and a series circuit, the series circuit including a reactor and the DC power supply, a first terminal of each of the second switches being connected to a junction between the output of the filter circuit and a corresponding one of the first switches in the first rectifier circuit, a second terminal of each of the second switches being connected to a first terminal of the series circuit including the reactor and the DC power supply, and a second terminal of the series circuit being connected to one of the output terminals of the first rectifier circuit,
wherein each switch of the first switches and the second switches is a bidirectional switch or a unidirectional switch, and
the series circuit is configured such that the AC motor driving circuit performs both power conversion to the first AC motor and charging of the DC power supply.
10. The AC motor driving circuit according to claim 9 , wherein the first switches are bidirectional switches.
11. The AC motor driving circuit according to claim 9 , wherein the second switches are bidirectional switches.
12. The AC motor driving circuit according to claim 9 , wherein the first switches are unidirectional switches having reverse blocking capabilities.
13. The AC motor driving circuit according to claim 9 , wherein the second switches are unidirectional switches having reverse blocking capabilities.
14. The AC motor driving circuit according to claim 9 , wherein electric power from the first AC motor is regenerated in the AC power supply through the first rectifier circuit.
15. The AC motor driving circuit according to claim 9 , wherein the DC power supply is charged with electric power regenerated from the first AC motor through the second rectifier circuit.
16. An electric car driving circuit comprising the AC motor driving circuit according to claim 9 , wherein the AC power supply is a second AC motor driven by an internal combustion engine.