An inverter apparatus, wherein, comprising an n-phase bridge inverter circuit and n iron cored winding coil combinations, where n=2k+1, and k is an integer greater than or equal to 2;
- the n-phase bridge inverter circuit is composed of n groups of unidirectional conductive electronic switch devices connected pairwise in series, including 2n unidirectional conductive electronic switch devices in total, namely:
- S1+, S1−;
- S2+, S2−;
- S3+, S3−;
- . . . Sn−1+, Sn−1−;
- Sn+, Sn−;
- both of the two unidirectional conductive electronic switch devices connected pairwise in series are connected to a positive pole of a DC power source at one end, and connected to a negative pole of the DC power source at the other end;
- at any time, at most one of the two unidirectional conductive electronic switch devices connected pairwise in series is in an ON state, so that the potential at a series connection point can be either a positive pole potential or a negative pole potential of the DC power source, or can be in a high-impedance state, i.e., when both of the two unidirectional conductive electronic switch devices are in an OFF state, the potential can be any value determined by other factors;
- the n iron cored winding coil combinations employ a star connection mode, i.e., the n iron cored winding coil combinations are connected together at one end, and connected to the connection points of the n unidirectional conductive electronic switch devices connected pairwise in series in the n-phase bridge inverter circuit at the other end;
- alternatively, the n iron cored winding coil combinations employ a polygonal connection mode, i.e., the n iron cored winding coil combinations are connected end to end in a specific order to form a closed loop, and n connection points in the polygonal connection mode are connected to the series connection points of the n groups of unidirectional conductive electronic switch devices connected pairwise in series in the n-phase bridge inverter circuit;
- the 2n unidirectional conductive electronic switch devices perform switching actions according to a pre-determined switching sequence:
- if the action time of the switches is not taken into account, then, in each action, one switch is closed, while another switch is opened at the same time, to ensure that a pair of switches are always connected;
- if the action time of the switches is taken into account, then, at any moment, two or three unidirectional conductive electronic switch devices among the 2n unidirectional conductive electronic switch devices are in an ON state, i.e., at a switching moment of the unidirectional conductive electronic switch devices, the unidirectional conductive electronic switch devices that are being switched on and the unidirectional conductive electronic switch devices that are being switched off are in an ON state simultaneously;
- at that point, the switching-on sequence of the unidirectional conductive electronic switch devices is as follows:
- (S1+, Sk+1−), (S1+, S2+, Sk+1−), (S2+, Sk+1−), (S2+, Sk+1−, Sk+2−), (S2+, Sk+2−),
- (S2+, S3+, Sk+2−), (S3+, Sk+2−), (S3+, Sk+2−, Sk+3−), (S3+, Sk+3−),
- . . .
- (S2k+, Sk−1−, Skk−), (S2kk+, Sk−), (S2k+, S2k+1+, Sk−), (S2k+1+, Sk−),
- (S2k+1+, Skkk−, Sk+1−), (S2k+1+, Sk+1−), (S2k+1+, S1+, Sk+1−),
- the cycle is repeated→(S1+, Sk+1−) . . .
- there is a definite electromagnetic induction relationship between the iron cored winding coils, so that a given DC power source generates an n-phase AC voltage source at n connection points of the n iron cored winding coil combinations and n series connection points of the n groups of unidirectional conductive electronic switch devices connected pairwise in series in the n-phase bridge inverter circuit, or generates n n-phase step wave AC voltage sources that approximate the n-phase AC power source;
- the n-phase AC voltage source comprises n sine wave voltage sources, which have equal amplitudes and have phases at an interval of 360°/n in sequence;
- the n-phase step wave AC voltage source comprises n step wave AC voltage sources, which have equal amplitudes and have fundamental wave phases at an interval of 360°/n in sequence.