Resonant single stage DC-AC converter with capacitors forming a half-bridge

• US 9,531,299 B2
• Filed: 12/28/2012
• Issued: 12/27/2016
• Est. Priority Date: 12/28/2011
• Status: Active Grant

• Current Assignee: Delta Electronics Thailand Public Company Limited (Delta Electronics Incorporated)
• Original Assignee: DET International Holding Limited (Delta Electronics Incorporated)
• Inventors: Bucheru, Bogdan Tudor
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Quddus, Nusrat
• Application Number:
  US14/368,429
• Publication Number:
  US 20140334215A1
• Time in Patent Office: 1,460 Days
• Field of Search: 363/95, 363/97, 363/98, 363131-133
• US Class Current: 1/1
• CPC Class Codes: H02M 1/44 Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 7/4807 having a high frequency intermediate AC stage
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/538 in a push-pull configuration H02M7/5375 takes precedence ; with oscillating arrangements H02M7/53832, H02M7/53846
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: Y02B 70/10 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

Abstract

A new and useful circuitry for DC to AC single stage conversion are presented, with the advantages of bi-directionality, resonant power transfer, high efficiency and simplicity. The output voltage dual polarity is achieved by means of control, synchronizing the output switch with one or the other of the primary switches. The invention also provides the means of canceling the common noise of the magnetic transformer.

Claims

1. Circuitry for DC to AC conversion, comprising:

a DC input;

an AC output; and

a resonant bidirectional single stage coupling the DC input to the AC output, said resonant bidirectional single stage comprising a magnetic transformer T1 that has a primary winding T1;

1 connected with a non-dotted end to capacitors C1 and C2 forming a first part of a half-bridge structure, and with a dotted end connected to inductor LLK, which is further connected to switches S1 and S2 forming a second part of the said half-bridge structure, where the T1 transformer has a secondary winding T1;

2 connected with a non-dotted end to an AC line phase L and with a dotted end to an output switch So that makes a connection with an AC line phase N.

2. The circuitry of claim 1, where depending on a polarity of an AC output voltage the So output switch is synchronized with the one or the other of S1 or S2 switches.

3. The circuitry of claim 1, where during output AC voltage zero crossing periods, the output switch So is maintained OFF and a voltage of a capacitive node of a primary bridge (VC) is moved from a last position at an end of a previous AC line semi-cycle to a starting position of a next AC line semi-cycle, by means of varying a switching time of S1 and S2 primary switches.

4. Circuitry for DC to AC conversion, comprising:

a DC input;

an AC output; and

a resonant bidirectional single stage coupling the DC input to the AC output, said resonant bidirectional single stage, comprising a magnetic transformer T1 that has a primary winding T1;

1 connected with a non-dotted end to capacitors C1 and C2 forming a first part of a half-bridge structure, and with a dotted end connected to an inductor LLK, which is further connected to switches S1 and S2 forming a second part of the said half-bridge structure, where T1 transformer has two identical windings T1;

2 and T1;

3, with the T1;

2 winding being connected with a non-dotted end to an L side of an AC line and with a dotted end to a first side of the switch So, while the T1;

3 winding is connected with a non-dotted end to a second side of the switch So and with a dotted end to an N side of the AC line.

5. The circuitry of claim 4, where depending on a polarity of an AC output voltage the So output switch is synchronized with the one or the other of S1 or S2 primary switches.

6. The circuitry of claim 4, where during output AC voltage zero crossing periods, the output switch So is maintained OFF and a voltage of a capacitive node of a primary bridge (VC) is moved from a last position at an end of a previous AC line semi-cycle to a starting position of a next AC line semi-cycle, by means of varying a switching time of S1 and S2 primary switches.