# US 2018/0323701 A1 · Power conversion apparatus and control method for power conversion apparatus

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- Number: US 2018/0323701 A1
- Document ID: US20180323701A1
- Status: Published application
- Kind: A1
- Application number: 15/781,281
- Filed: 2016-12-23
- Published: 2018-11-08
- Earliest claimed: 2016-01-12
- Assignees: Sumitomo Electric Industries, Ltd.
- Applicants: Sumitomo Electric Industries, Ltd.
- Inventors: Takaaki Sano; Takeshi Ariyoshi; Keiji Tashiro
- Web page: https://patentgrep.com/patent/US20180323701A1

## CPC

- H02M 1/126: {using passive filters}
- H02M 1/4266: {using passive elements}
- H02M 1/088: for the simultaneous control of series or parallel connected semiconductor devices
- H02M 1/4233: {using a bridge converter comprising active switches}
- H02M 1/44: Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
- H02M 3/33584: {Bidirectional converters}
- H02M 7/12: using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M 7/48: using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M 7/797: using semiconductor devices only
- H02M 1/0009: {Devices or circuits for detecting current in a converter}
- H02M 1/007: {Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826)}
- H02M 3/33573: {Full-bridge at primary side of an isolation transformer}
- 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
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A power conversion apparatus comprises a bidirectional conversion circuit that enables first conversion converting DC to AC and second conversion converting AC to DC and a filter circuit that is provided on an AC side of the bidirectional conversion circuit and that includes a capacitor. A control unit is provided for performing control such that the bidirectional conversion circuit makes the first conversion during the former stage of each half cycle of AC voltage, and performing control such that the bidirectional conversion circuit makes the second conversion during the latter stage of each half cycle of AC voltage. The control unit performs control such that AC current of an opposite polarity to that of the AC voltage flows to an AC side of the bidirectional conversion circuit during the former stage and performs control such that AC current of the same polarity as that of the AC voltage flows to the AC side of the bidirectional conversion circuit during the latter stage.

## Claims

### Claim at position 1

-4. (canceled)

### Claim 5

A power conversion apparatus, comprising a bidirectional conversion circuit that enables first conversion converting DC to AC and second conversion converting AC to DC; and a filter circuit that is provided on an AC side of the bidirectional conversion circuit and includes a capacitor, further comprising:
a control unit performing control such that the bidirectional conversion circuit makes the first conversion during a former stage of each half cycle of AC voltage, and performing control such that the bidirectional conversion circuit makes the second conversion during a latter stage of each half cycle of AC voltage, wherein
the control unit performs control such that AC current of a polarity opposite to a polarity of the AC voltage flows to an AC side of the bidirectional conversion circuit during the former stage and performs control such that AC current of a same polarity as a polarity of the AC voltage flows to an AC side of the bidirectional conversion circuit during the latter stage.

### Claim 6 (depends on 5)

The power conversion apparatus according to claim 5, comprising:
a voltage detection unit that detects voltage on an AC side of the bidirectional conversion circuit;
a current detection unit that detects current on an AC side of the bidirectional conversion circuit; and
a setting unit that sets a target value for phase delay with respect to a phase of AC voltage in order to cancel out phase advance by shunt current shunted through the filter circuit based on voltage detected by the voltage detection unit, current detected by the current detection unit and a predetermined value concerning the capacitor in the filter circuit,
wherein the former stage is a phase up to the target value within each half cycle, and the latter stage is a phase after the target value within each half cycle.

### Claim 7 (depends on 5)

The power conversion apparatus according to claim 5, wherein the bidirectional conversion circuit comprises
a first series circuit that includes a first switching element and a second switching element connected in series,
a second series circuit that includes a third switching element and a fourth switching element connected in series and that is connected to the first series circuit in parallel, and
a diode connected in antiparallel to each switching element, wherein
the control unit performs control so as to repeatedly switch between a state where the first switching element and the fourth switch element are turned on and a state where the fourth switching element is turned on, during the former stage of each positive half cycle of AC voltage, and to repeatedly switch between a state where the second switching element and the third switching element are turned on and a state where the second switching element is turned on, during the former stage of each negative half cycle of AC voltage, and
the control unit further performs control so as to repeat a state where the second switching element is turned on during the latter stage of each positive half cycle of AC voltage and to repeat a state where the fourth switching element is turned on during the latter stage of each negative half cycle of AC voltage.

### Claim 8 (depends on 6)

The power conversion apparatus according to claim 6, wherein the bidirectional conversion circuit comprises
a first series circuit that includes a first switching element and a second switching element connected in series,
a second series circuit that includes a third switching element and a fourth switching element connected in series and that is connected to the first series circuit in parallel, and
a diode connected in antiparallel to each switching element, wherein
the control unit performs control so as to repeatedly switch between a state where the first switching element and the fourth switch element are turned on and a state where the fourth switching element is turned on, during the former stage of each positive half cycle of AC voltage, and to repeatedly switch between a state where the second switching element and the third switching element are turned on and a state where the second switching element is turned on, during the former stage of each negative half cycle of AC voltage, and
the control unit further performs control so as to repeat a state where the second switching element is turned on during the latter stage of each positive half cycle of AC voltage and to repeat a state where the fourth switching element is turned on during the latter stage of each negative half cycle of AC voltage.

### Claim 9

A control method for a power conversion apparatus comprising a bidirectional conversion circuit that enables first conversion converting DC to AC and second conversion converting AC to DC and a filter circuit that is provided on an AC side of the bidirectional conversion circuit and includes a capacitor, comprising:
performing control by a control unit such that the bidirectional conversion circuit makes the first conversion during a former stage of each half cycle of AC voltage, and
performing control by the control unit such that the bidirectional conversion circuit makes the second conversion during a latter stage of each half cycle of AC voltage,
wherein the control unit performs control such that AC current of a polarity opposite to a polarity of the AC voltage flows to the AC side of the bidirectional conversion circuit during the former stage and performs control such that AC current of a same polarity as a polarity of the AC voltage flows to an AC side of the bidirectional conversion circuit during the latter stage.