KR20150010011A - Power conditioning system and Method of driving the same - Google Patents

Abstract

A power converting device according to an embodiment includes a battery part which charges a voltage from a system; a converting part which converts a voltage between the system and the battery part; and a power part which supplies a power voltage to the converting part and the battery part. The power part includes a first transformer which receives a voltage from the system and supplies a power voltage to the converting part and the battery part; and a second transformer which receives a voltage from the battery part and applies the voltage to the first transformer.

Description

TECHNICAL FIELD [0001] The present invention relates to a power conversion system and a driving method thereof,

An embodiment relates to a power conversion apparatus.

The embodiment relates to a method of driving a power conversion apparatus.

A typical ESS (Energy Storage System) apparatus charges electricity when the demand of electric power is low on the system side. When the demand of electric power is high, electric power is supplied to the system by discharging the electric power of the power storage apparatus. At the same time, So as to stabilize the power.

The ESS apparatus includes a converter for receiving system power and converting the DC power into a DC power, converting the received DC power to AC power, and transmitting the DC power to the system side and the load side, a power storage unit for supplying DC power from the battery to the conversion unit, A step-up / down unit for stepping up or stepping down a direct current voltage between the converting unit and the power storage unit, a control unit for controlling operations of the respective components, and a power supply unit for supplying driving voltages to the respective components.

The power supply unit of the conventional ESS apparatus receives a voltage from the output terminal of the conversion unit, divides it, and supplies the driving voltage to the respective components. At this time, since the voltage received from the output terminal of the converting unit is a high voltage, the elements constituting the power supply unit must be constituted with a high capacity, resulting in an increase in manufacturing cost.

The embodiment provides a power conversion apparatus capable of reducing the capacity of the internal configuration of the power supply unit.

The embodiment provides a method of driving a power conversion apparatus capable of supplying a stable power supply voltage.

A power conversion apparatus according to an embodiment includes: a power storage unit for charging a voltage from a system; A converter for converting a voltage between the system and the power storage unit; And a power supply unit for supplying a power supply voltage to the conversion unit and the power storage unit, wherein the power supply unit includes: a first transformer for receiving a voltage from the system and supplying the power supply voltage to the conversion unit and the power storage unit; And a second transformer receiving a voltage from the power storage unit and applying a voltage to the first transformer.

A method of driving a power conversion apparatus according to an embodiment includes: applying a system output voltage from a system to a first transformer; The first transformer generating a power supply voltage with the system output voltage; Applying the power supply voltage to the converting unit and the power storage unit; Applying a power storage output voltage of the power storage unit to a second transformer; The second transformer dividing the power storage output voltage and applying it to the first transformer; And the first transformer divides the voltage from the second transformer to generate and supply a power supply voltage.

The power supply unit of the power conversion apparatus according to the embodiment uses two transformers and a voltage directly applied from the system can be lowered to lower the voltage level applied to the power supply unit so that the capacity of the internal configuration of the power supply unit can be reduced, have.

The method of driving a power conversion apparatus according to an embodiment of the present invention can supply an initial power supply voltage by receiving a voltage from a system and supply a power supply voltage through a power storage unit even after a system and a power conversion apparatus are separated, It is possible to supply.

1 is a block diagram illustrating an energy storage system according to an embodiment.
2 is a block diagram showing a power conversion apparatus according to an embodiment.
3 is a circuit diagram showing a power conversion apparatus according to an embodiment.
4 is a flowchart illustrating a method of driving the power conversion apparatus according to the embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between .

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

1 is a block diagram illustrating an energy storage system according to an embodiment.

Referring to FIG. 1, an energy storage system according to an embodiment may include a system 10, a load 20, a power inverter 30, and a switch 40.

The system (10) transfers power to the load (20) and the power inverter (30). The system 10 can supply the power required for the consumption of the load 20 and the power required for charging the power conversion device 30. [ The system 10 provides the power conversion device 30 with various information necessary for charging or discharging determination of the power conversion device 30 and information necessary for calculating the electricity rate, . ≪ / RTI > The system 10 may include various management servers for managing electricity usage and electricity charges. The system 10 may be a vehicle, a solar cell, a domestic power storage system, or the like.

The load 20 may receive power from the system 10 or the power conversion device 30 and consume the power. The load 20 is supplied with power from the system 10 when the switch 40 is short-circuited and can be supplied with electric power from the power conversion device 30 when the switch 40 is opened.

The power conversion device 30 receives electricity tariff information that changes in real time from the system 10 and purchases electricity from the system 10 and stores the electricity in a battery or stores the stored electricity into the system 10 can do. Further, the power converter 30 can supply the charged electricity to the load 20. [ The power conversion device 30 may receive information on the amount of charged electricity charged in the battery from an internal battery, thereby charging or discharging electricity to the battery.

The power conversion apparatus 30 is connected to the system 10 and the load 20 by a variety of communication methods including a wired or wireless communication method and a power line communication method, To each other.

The power conversion device 30 transmits charge information of the system 10 that is a basis for charge / discharge, charge amount or discharge amount measurement information for charge calculation, purchase and expenditure information to / from the system 10, .

In addition, the power converter 30 can set various charging and discharging criteria and criteria for purchase and sale based on the charging information of the system 10, which is a reference of the charging / discharging, .

In addition, the power conversion apparatus 30 transmits the amount of sales and purchase of the system 10 and the electric power (electricity) and the cost information to the system 10 through the user information recognition, charges the cost, The system 10 can transmit or receive information related to the billing function,

The charge / discharge control of the power converter 30 and the power transfer to the load 20 are determined by the power converter 30. However, the charge / discharge control and the charge / Power transmission judgment can be made. In this case, the power converter 30 may perform charge / discharge under the control of the controller.

2 is a block diagram showing a power conversion apparatus according to an embodiment.

Referring to FIG. 2, the power converter 30 according to the embodiment may be connected to the system 10.

The power conversion apparatus 30 may include a controller 100, a filter unit 110, a conversion unit 120, a decompression unit 130, a power storage unit 140, and a power supply unit 150.

The power conversion apparatus 30 stores the AC input power transmitted from the system 10 under the control of the control unit 100 in the power storage unit 140 and outputs the AC input power to the power storage unit 140, Power can be generated from the power storage unit 140 toward the system 10.

The control unit 100 may apply a control signal for controlling the filter unit 110, the conversion unit 120, the decompression unit 130, the power storage unit 140, and the power supply unit 150 in each configuration. The control unit 100 may control charge / discharge between the system 10 and the power storage unit 140.

The filter unit 110 may filter the noise or surge voltage generated from the output of the system 10 or the conversion unit 120 or the input AC power source. The filter unit 110 may operate as a bidirectional filter.

The converter 120 is a bidirectional converter that rectifies the input AC power when the power storage unit 140 is charged from the system 10 and smoothly transmits the smoothed power to the power storage unit 130, The DC voltage of the power storage unit 140 may be converted into an AC voltage and transmitted to the system 10 through the filter unit 110. [ In other words, the converting unit 120 can convert an AC voltage to a DC voltage, and convert a DC voltage to an AC voltage.

The boosting and depressurizing unit 130 may reduce the DC voltage supplied from the converting unit 120 to a level that the power storage unit 140 can store and deliver the reduced voltage to the power storage unit 140. The boost / depressurization unit 130 boosts the DC voltage supplied from the power storage unit 140 and transmits the boosted DC voltage to the conversion unit 120.

The power storage unit 140 may be a battery. The power storage unit 140 stores a DC voltage transmitted from the system 10 through the pressure reducing unit 130 and outputs the stored DC voltage according to a control signal from the controller 100 .

The power supply unit 150 may apply a power supply voltage to each configuration of the power conversion apparatus 30. FIG. The power supply unit 150 receives the AC voltage from the system 10 and receives the DC voltage from the power storage unit 140 and divides the AC voltage and the DC voltage to generate a power supply voltage, 30). ≪ / RTI >

Since the power converter 30 requires different power supply voltages depending on the configuration, the power supply 150 may generate the power supply voltage by dividing the AC voltage and the DC voltage into a plurality of different levels.

The power supply unit 150 may apply a power supply voltage to each configuration of the energy storage system as well as to each configuration of the power inverter 30.

The power supply unit 150 may include a first transformer 151 and a second transformer 153.

The first transformer 151 may have a structure symmetrical with the second transformer 153.

The first transformer 151 receives the AC voltage from the system 10 and rectifies and divides the AC voltage to generate a power supply voltage having a plurality of different levels to be supplied to each configuration of the power inverter 30 can do.

The second transformer 153 receives the DC voltage from the power storage unit 140, divides the DC voltage, and transmits the divided voltage to the first transformer 151.

In other words, the first transformer 151 receives AC voltage from the system 10, generates a power supply voltage, and applies the AC voltage to the power converter 30, And charges the power storage unit 140 with a voltage. The power storage unit 140 transfers the DC voltage to the second transformer 153 and the second transformer 153 divides the voltage and transfers the divided voltage to the first transformer 151, Level power supply voltage.

The first transformer 151 can generate a power supply voltage required for the initial operation of each configuration of the power inverter 30 by receiving AC voltage from the system 10 for the first time. The first transformer 151 receives the direct current voltage from the second transformer 153 so that the power storage unit 140 and the power storage unit 130 are disconnected from each other even if the system 10 and the power inverter 30 are disconnected. It is possible to stably generate the power supply voltage.

The second transformer 153 receives a direct current voltage from the power storage unit 140 rather than the output terminal of the converter unit 120 so that the DC voltage having a relatively lower level than the output terminal of the converter unit 120 . Also, the first transformer 151 is applied with an AC voltage having an effective value lower than that of the output terminal of the converting unit 120. The first transformer 151 and the second transformer 153 receive the relatively low level voltage compared to the prior art so that the first transformer 151 and the second transformer 153 are connected to the internal structures . Thus, the manufacturing cost of the power conversion device 30 including the power supply unit 150 can be reduced. In addition, the first transformer 151 and the second transformer 153 receive a relatively low level voltage compared to the prior art, so that the interval between the wirings to which the electric field effect is to be considered can be reduced. As a result, The size of the printed circuit board can be reduced and the size of the power converter 30 can be reduced.

In another embodiment, the second transformer 153 may generate a power supply voltage having a plurality of different levels of direct-current voltages received from the power storage unit 140 and apply the power voltage to the respective configurations of the power inverter 30 have. In this case, the first transformer 151 generates and supplies the initial power source voltage of the power converter 30, and thereafter generates a power source voltage through the second transformer 153 and supplies the power source voltage to the power converter 30 ).

The first transformer 151 and the second transformer 153 may be a boost converter, a buck converter, a buck-boost converter, a fly-back converter, LCC converter (LLC converter).

3 is a circuit diagram showing a power conversion apparatus according to an embodiment.

Referring to FIG. 3, a system 10 is connected to the power conversion apparatus 30 according to the embodiment.

The system 10 can output AC voltage of three phases to the power conversion device 30. [

The system 10 can output three-phase AC voltage through three wires. The three wirings may be an R line, an S line, and a T line. The R line, the S line, and the T line may be defined in any order.

The three-phase AC voltage from the system 10 may be input to the filter unit 110 through R-line, S-line, and T-line. Although not shown, the three wires connecting the system 10 and the filter unit 110 are defined as R, S, and T lines in order from the top to the bottom.

The filter unit 110 may include first to sixth inductors L1 to L6 connected in series to three wirings.

The first inductor L1 and the fourth inductor L4 are connected in series to the R line, the second inductor L2 and the fifth inductor L5 are connected in series to the S line, The third inductor L3 and the sixth inductor L6 may be connected in series to the T line.

The first to third capacitors C1 to C3 may be connected between the R line, the S line, and the T line. The first capacitor (C1) may be connected between the R line and the S line, the second capacitor (C2) may be connected between the S line and the T line, and the third capacitor (C3) And may be connected between the T lines.

The filter unit 110 including the first to sixth inductors L1 to L6 and the first to third capacitors C1 to C3 supplies AC voltage from the system 10 to the power storage unit 140 It is possible to filter noise and static electricity that may occur during storage and to filter out static electricity that may occur when a voltage is output from the power storage unit 140 to the system 10. [

The conversion unit 120 may include first to sixth transistors Q1 to Q6, first to sixth diodes D1 to D6, and a connection capacitor Clink.

The first to sixth transistors Q1 to Q6 and the first to sixth diodes D1 to D6 may form a bridge between the first and second nodes N1 and N2.

The first to sixth transistors Q1 to Q6 may be controlled by the first to sixth signals S1 to S6, respectively. The first to sixth transistors Q1 to Q6 may be connected in parallel with the first to sixth diodes D1 to D6, respectively. The first to sixth signals S1 to S6 may be applied from the controller 100.

The first transistor Q1 and the first diode D1 are connected between the first node N1 and the third node N3 and the second transistor Q2 and the second diode D2 are connected between the first node N1 and the third node N3. The third transistor Q3 and the third diode D3 are connected between the first node N1 and the fifth node N5 and the third node N3 is connected between the first node N1 and the fourth node N4, .

The fourth transistor Q4 and the fourth diode D4 are connected between the second node N2 and the third node N3 and the fifth transistor Q5 and the fifth diode D5 are connected between the second node N2 and the third node N3, And the sixth transistor Q6 and the sixth diode D6 are connected between the second node N1 and the fifth node N5 and are connected between the second node N1 and the fourth node N4, .

Wherein the third node N3 is a contact point with the R line to which the fourth inductor L4 is connected and the fourth node N4 is a contact point with the S line to which the fifth inductor L5 is connected, And the node N5 may be a contact point with the T line to which the sixth inductor L6 is connected.

The first to sixth transistors Q1 to Q6 are turned on and off in pairs to convert the DC voltage of the first and second nodes N1 and N2 to an AC voltage to be supplied to the third to fifth nodes N3 to N5 Alternatively, the AC voltage of the third to fifth nodes N3 to N5 may be converted into the DC voltage and may be transmitted to the first and second nodes N1 and N2.

The first to sixth diodes D1 to D6 are protection elements for the first to sixth transistors Q1 to Q6, and can prevent the reverse current from flowing.

The connection capacitor Clink may be connected between the first and second nodes N1 and N2. The connection capacitor Clink stores the DC voltage applied from the voltage-down unit 130 and transfers the DC voltage to the first to sixth transistors Q1 to Q6. The first to sixth transistors Q1 to Q6 And smoothes the voltage input from the voltage-up / down unit 130 to the boost /

The voltage-down unit 130 includes two diodes Da and Db connected in parallel to two transistors Qa and Qb and a pair of the transistors Qa and Qb, And includes an inductor La and a capacitor Ca connected thereto. The voltage-decreasing unit 130 may reduce the voltage stored in the connection capacitor Clink of the transforming unit 120 and may transfer the voltage to the power storage unit 140. The voltage received from the power storage unit 140 may be And can be applied to the connection capacitor Clink of the conversion unit 120.

The power supply unit 150 may include a first transformer 151 and a second transformer 153. The first transformer 151 and the second transformer 153 may be a flyback converter. Since the first transformer 151 and the second transformer 153 are formed symmetrically with respect to each other, the description of the second transformer 153 is replaced with a description of the first transformer.

The first transformer 153 is composed of a coil having a winding ratio of n1: n2. The first transformer 153 includes a primary circuit, that is, a primary circuit connected to the input side coil and a secondary circuit connected to the secondary coil, that is, the output side coil. The primary circuit and the secondary circuit may be insulated by a coil.

The primary circuit of the first transformer 153 receives the AC voltage from the system 10. The first transformer 153 can receive a voltage of any one of three AC voltages of the system 10. In the drawing, the first transformer 153 can receive a voltage from an S line.

The primary circuit includes a snubber. The snubber may include a resistor Rsn, a capacitor Csn, and a diode Dsn. The snubber can protect the internal structure of the first transformer 151 by preventing an abrupt rise of the input current and voltage. The first transformer may transmit the voltage input from the S line to the primary coil through the snubber.

A transistor may be formed between the primary coil and the ground terminal of the primary circuit. The transistor may control an energy charging or transferring operation of the first transformer 153 by switching an input voltage in response to a control signal from the controller 100. The transistor may be controlled by an output voltage fed back from the secondary circuit.

The secondary circuit may be composed of a plurality of coils having different winding ratios. In the drawing, the secondary circuit has a circuit having a coil having a winding ratio of n2 and a winding ratio of n3, but may be a circuit having two or more coils. The secondary circuit may divide the input voltage applied to the primary circuit according to the respective winding ratios to a voltage of a different level and output the voltage.

A plurality of voltages output from the secondary circuit of the first transformer 151 can be used as the power supply voltage of the power inverter 30. [

The second transformer 152 may receive voltage from the power storage unit 140. A connection diode (Dlink) may be formed between the power storage unit 140 and the second transformer 152. The connection diode Dlink may prevent the voltage of the second transformer 152 from being applied to the power storage unit 140.

The primary circuit of the second transformer 152 receives the voltage of the power storage unit 140 and divides it to output a secondary output voltage to the secondary circuit.

The primary circuit of the first transformer 151 and the second transformer 152 may be electrically connected. The secondary output voltage may be transferred to the primary circuit of the first transformer 151 and used to generate the power supply voltage. In other words, the second transformer 152 divides the voltage from the power storage unit 140 to output a secondary output voltage, and the primary circuit of the first transformer 151 divides the secondary output voltage into a divided voltage So that a plurality of power supply voltages can be generated and applied to each configuration of the power conversion apparatus.

4 is a flowchart illustrating a method of driving the power conversion apparatus according to the embodiment.

4, in the driving method of the power conversion apparatus according to the embodiment, the voltage output from the system 10 is applied to the first transformer 151 (S101)

The voltage output from the system 10 is applied only to the first transformer 151 and the power converter 30 is not supplied with the power voltage so that the power converter 30 is not operated .

The first transformer 151 divides the voltage from the system 10 to generate a plurality of power supply voltages having different levels (S102)

The secondary side of the first transformer 151 applies the power supply voltage to each configuration of the power inverter 30. (S103)

The power converter 30 is operated in response to the power supply voltage. The first transformer 151 can generate a voltage necessary for initial operation of each configuration of the power converter 30 by receiving an AC voltage from the system 10.

The voltage from the system 10 is applied to the power storage unit 140 via the filter unit 110, the conversion unit 120 and the boost / decrease unit 130, and the power storage unit 140 is charged with a voltage (S104)

The voltage of the power storage unit 140 is transferred to the primary circuit of the second transformer 153. The first transformer 153 divides the voltage transferred to the primary circuit and outputs it as a secondary output voltage to the secondary circuit.

The second transformer 153 receives a direct current voltage from the power storage unit 140 rather than the output terminal of the conversion unit 120 so that a DC voltage having a relatively lower level than the output terminal of the conversion unit 120 is received . The second transformer 153 may be configured to have a small capacity internal structure by receiving a relatively low level voltage of the conventional transformer 153. Thus, the manufacturing cost of the power conversion device 30 including the power source unit 150 can be reduced, and the size of the printed circuit board on which the power source unit 150 is formed can be reduced.

The second transformer 153 applies the secondary output voltage to the primary side of the first transformer 151. The first transformer 151 divides the secondary output voltage to generate a power supply voltage (S106)

The first transformer 151 can be supplied with the voltage of the power storage unit 140 through the second transformer 153 so that even if the system 10 is disconnected from the power conversion apparatus 30 , The power supply voltage can be stably generated using the electric power charged in the power storage unit 140.

10: System
20: Load
30: Power converter
40: Switch
100:
110:
120:
130:
140:
151: first transformer
152: second transformer

Claims (10)

A power storage unit for charging a voltage from the system;
A converter for converting a voltage between the system and the power storage unit; And
And a power supply unit for supplying a power supply voltage to the conversion unit and the power storage unit,
The power supply unit,
A first transformer for receiving a voltage from the system and supplying a power supply voltage to the converter and the power storage unit; And
And a second transformer that receives a voltage from the power storage unit and applies a voltage to the first transformer. The method according to claim 1,
Wherein the first transformer divides the voltage from the system and supplies the initial power supply voltage of the converter and the power storage unit. The method according to claim 1,
Wherein the first transformer divides the voltage from the second transformer to supply the power source voltage after the system is separated to the converter and the power storage unit. The method according to claim 1,
And the secondary circuit of the second transformer is connected to the primary circuit of the first transformer. The method according to claim 1,
Wherein the first transformer and the second transformer are flyback converters. Applying a system output voltage from the system to the first transformer;
The first transformer generating a power supply voltage with the system output voltage;
Applying the power supply voltage to the converting unit and the power storage unit;
Applying a power storage output voltage of the power storage unit to a second transformer;
The second transformer dividing the power storage output voltage and applying it to the first transformer; And
And the first transformer divides the voltage from the second transformer to generate and supply a power supply voltage. The method according to claim 6,
Wherein the first transformer supplies the initial power supply voltage of the converter and the power storage unit from the system output voltage. The method according to claim 6,
Wherein the first transformer supplies the power source voltage after the system is separated from the voltage from the second transformer to the converter and the power storage unit. The method according to claim 6,
And the secondary circuit of the second transformer is connected to the primary circuit of the first transformer. The method according to claim 6,
Wherein the first transformer and the second transformer are flyback converters.

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