Electric power convertion apparatus and method of operating the same

Patent metadata

Field	Value
Publication number	US-2016352236-A1
Application number	US-201615166042-A
Country	US
Kind code	A1
Filing date	May 26, 2016
Priority date	May 29, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

Some embodiments include an electric power conversion apparatus, which may include a transformer, a first converter connected to a primary side of the transformer, a second converter connected to a secondary side of the transformer, a first capacitor connected to the first converter, a second capacitor connected to the second converter, and a control unit for controlling the first converter and the second converter, wherein the control unit may determine operation ranges with respect to a plurality of modulation methods, may determine a modulation method including an output electric power value of the electric power conversion apparatus among the operation ranges of the plurality of modulation methods, and may output control signals of the first converter and the second converter based on the determined modulation method, wherein the control signals correspond to an instruction value.

First claim

What is claimed is:

1 . An electric power conversion apparatus, comprising:
a transformer; a first converter connected to a primary side of the transformer; a second converter connected to a secondary side of the transformer; a first capacitor connected to the first converter; a second capacitor connected to the second converter; and a control unit configured to control the first converter and the second converter, wherein the control unit is configured to: determine operation ranges with respect to a plurality of modulation methods, determine a modulation method including an output electric power value of the electric power conversion apparatus among the operation ranges of the plurality of modulation methods, and output control signals of the first converter and the second converter based on the determined modulation method, wherein the control signals correspond to an instruction value.

2 . The electric power conversion apparatus of claim 1 , wherein the first converter includes first and second switching elements of a first leg and third and fourth switching elements of a second leg, and the second converter includes fifth and sixth switching elements of a third leg and seventh and eighth switching elements of a fourth leg.

3 . The electric power conversion apparatus of claim 1 , wherein the first converter includes first and second legs and the second converter includes third and fourth legs, and wherein the first leg includes:
a first switching element group including first and second switching elements connected in parallel with each other; and a second switching element group including third and fourth switching elements connected in parallel with each other, wherein the second leg includes:
a third switching element group including fifth and sixth switching elements connected in parallel with each other; and
a fourth switching element group including seventh and eighth switching elements connected in parallel with each other,
wherein the third leg includes:
a fifth switching element group including ninth and tenth switching elements connected in parallel with each other; and
a sixth switching element group including eleventh and twelfth switching elements connected in parallel with each other, and
wherein the fourth leg includes:
a seventh switching element group including thirteenth and fourteenth switching elements connected in parallel with each other; and
an eighth switching element group including fifteenth and sixteenth switching elements connected in parallel with each other.

4 . The electric power conversion apparatus of claim 1 , wherein the control unit includes:
a controller configured to output a control variable corresponding to a voltage instruction value; a mode selector configured to output a select signal of one modulation method among the plurality of modulation methods based on the output electric power value; and a control signal output unit configured to output a first switching signal for controlling the first converter and a second switching signal for controlling the second converter by applying the modulation method selected through the mode selector based on the control variable output through the controller.

5 . The electric power conversion apparatus of claim 4 , wherein the controller includes:
a first calculator configured to output a difference value between the voltage instruction value and an output voltage value; a proportional integral controller configured to perform a proportional integral on an output value of the first calculator to output the control variable; and a second calculator configured to output the output electric power value according to a product of the output voltage value and an output current value.

6 . The electric power conversion apparatus of claim 5 , wherein the controller further includes a third calculator configured to receive an input voltage value and the output voltage value to calculate and output an input/output voltage ratio,
and wherein the mode selector selects a modulation method based on an operation condition according to the input/output voltage ratio output through the third calculator, and based on the output electric power value.

7 . The electric power conversion apparatus of claim 6 , wherein the modulation method includes:
a first modulation method corresponding to a dual pulse width modulation method; a second modulation method corresponding to a triangular pulse width modulation method; a third modulation method corresponding to a single pulse width modulation method; and a fourth modulation method corresponding to a phase shift modulation (PSM) method, wherein the mode selector stores an operation range corresponding to each of the modulation methods, verifies a modulation method in which the output electric power is included based on the stored operation range, and outputs a select signal of the verified modulation method.

8 . The electric power conversion apparatus of claim 7 , wherein:
the electrical power value included in the operational range of the first modulation method is less than that of the second modulation method; the electrical power value included in the operational range of the second modulation method is less than that of the third modulation method; and the electrical power value included in the operational range ofthe third modulation method is less than that of the fourth modulation method.

9 . The electric power conversion apparatus of claim 7 , wherein the operation condition includes:
a step-up condition in which an output voltage is greater than an input voltage; and a step-down condition in which the output voltage is equal to or less than the input voltage, wherein the mode selector separately stores an operation range in the step-up condition and an operation range in the step-down condition by corresponding to each of the modulation methods.

10 . The electric power conversion apparatus of claim 7 , wherein the control signal output unit is further configured to receive operation direction information of the electric power conversion apparatus, and to output the first switching signal and the second switching signal using the received operation direction information, and
wherein the operation direction information includes: a first direction operation condition in which a voltage is output from the first converter to the second converter; and a second direction operation condition in which the voltage is output from the second converter to the first converter.

11 . The electric power conversion apparatus of claim 7 , wherein the control signal output unit is further configured to compare a currently selected modulation method with a previously applied modulation method, and to adjust the received control variable if the current modulation method and the previous modulation method are different to each other.

12 . A method of operating an electric power conversion apparatus, which includes a transformer, a first converter connected to a primary side of the transformer and including a plurality of switching elements of a first leg and a plurality of switching elements of a second leg, and a second converter connected to a secondary side of the transformer and including a plurality of switching elements of a third leg and a plurality of switching elements of a fourth leg, comprising:
calculating an output electric power value using an output voltage value and an output current value of the electric power conversion apparatus; determining whether an operation condition of the electric power conversion apparatus is a step-down condition or a step-up condition using an input voltage

Assignees

• Lsis Co Ltd

Inventors

• Yoo Anno
• Cho Young-Hoon
• Byen Byeng-Joo

Classifications

• H02M3/33584 Primary

  Bidirectional converters · CPC title

• H02M3/33523 Primary

  with galvanic isolation between input and output of both the power stage and the feedback loop · CPC title

• H02M2001/0009

  Electricity · mapped topic

• H02M3/33546 Primary

  with automatic control of the output voltage or current (H02M3/33561 takes precedence) · CPC title

• H02M1/08

  Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters · CPC title