KR102085816B1 - Power conditioning system and Energy storage system - Google Patents

Abstract

Power conversion apparatus according to the embodiment, the connecting portion for converting the AC voltage from the three-phase five-wire system to a single phase; A power storage unit charging a voltage from the system; And a converter for converting a voltage between the connection part and the power storage part.

Description

Power conversion system and energy storage system

Embodiments relate to a power converter.

Embodiments relate to an energy storage system.

A typical ESS (Energy Storage System) device charges when the demand for power is low on the grid side, and discharges power from the storage unit when the demand for power is high, and simultaneously supplies reactive power to the grid. It has a role of stabilizing power by instantaneous correction.

The PCS (Power conditioning system) included in the ESS device receives a grid-side power, converts the power into DC power, converts the received DC power into AC power, and transfers the power to the grid and the load. The electrical storage part supplied to the said conversion part is provided.

When the system uses a three-phase five-wire system and an external power supply such as a solar cell is connected to one phase, there is a problem in that the PCS connected in a single phase does not receive power from an external power supply.

The embodiment provides a power converter that can be used in a three-phase five-wire system and an energy storage system including the same.

Power conversion apparatus according to the embodiment, the connecting portion for converting the AC voltage from the three-phase five-wire system to a single phase; A power storage unit charging a voltage from the system; And a converter for converting a voltage between the connection part and the power storage part.

Energy storage system according to the embodiment, a system for supplying power in a three-phase five-wire system; A load consuming the power; A power converter configured to store power from the system or to supply stored power to the load, wherein the power converter comprises: a connection unit converting an AC voltage from the system into a single phase; A power storage unit charging a voltage from the system; And a converter for converting a voltage between the connection part and the power storage part.

In the power converter and the energy storage system including the same, the single-phase power converter may be used in a three-phase five-wire type by using a relay unit having one end connected to a three-phase line and the other end connected to a converter.

1 is a block diagram illustrating an energy storage system according to an exemplary embodiment.
2 is a view showing a power conversion apparatus according to an embodiment.
3 is a view showing a power conversion apparatus according to another embodiment.
4 is a block diagram showing in detail the converter 100 of the power change apparatus according to the embodiment.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

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

Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, except to exclude other components unless specifically stated otherwise. In addition, the terms “… unit”, “… unit”, “module”, etc. described in the specification mean a unit that processes at least one function or operation, which 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 exemplary embodiment.

Referring to FIG. 1, the energy storage system 1 according to the embodiment includes a system 10, a load 20, a power converter 30, a solar cell 40, a controller 50, and a switch 60. can do.

The system 10 supplies power to the load 20 and the power converter 30. The system 10 may supply power for consumption of the load 20 and supply power for charging the power converter 30.

The system 10 is a system for providing the controller 50 with various information necessary for the charging or discharging of the power converter 30 and information for calculating the electric charge. The system 10 may include a system such as a power exchange. Can be. The system 10 may include various management servers that manage electricity usage and electricity bills. The system 10 may be a vehicle or a home power storage system.

The system 10 may be connected to the load 20, the power converter 30, and the solar cell 40 in a three-phase five-wire manner.

The load 20 may receive power from the system 10, the power converter 30, or the solar cell 40 to consume it. The load 20 may receive power from the system 10 when the switch 60 is shorted, and may receive power from the power converter 30 when the switch 60 is opened. In addition, the load 20 may be supplied with power to the solar cell 40 under the control of the controller 50.

The power converter 30 may purchase electricity from the system 10 and store it in a storage battery under the control of the controller 50, or sell the stored electricity to the system 10. In addition, the power converter 30 may store electricity from the solar cell 40 in the storage battery under the control of the controller 50. In addition, the power converter 30 may supply the charged electricity to the load 20. The power converter 30 may receive the charge information of the charged electricity from the internal battery, and transmit it to the controller 50.

The solar cell 40 may supply power to the system 10, the load 20, and the power converter 30. The solar cell 40 may generate power to supply power for consumption of the load 20, supply power for charging the power converter 30, and also supply power to the system 10. Can be passed. The solar cell 40 may transmit power to the system 10, the load 20, or the power converter 30 under the control of the controller 50. In the drawings, the solar cell 40 has been described as an example, but may be a renewable energy source other than the solar cell 40.

The controller 50 includes a wired or wireless communication method and a power line communication (PLC) method with the system 10, the load 20, the power converter 30, and the solar cell 40. The communication method can transmit or receive information necessary for charging / discharging electricity.

The controller 50 may transmit or receive charge information of the system 10 as a reference for charge / discharge, charge or discharge amount measurement information for calculating a charge, and purchase and expense information with the system 10. Can be.

In addition, the controller 50 may set various charging and discharging standards and purchasing and selling standards through the remote control based on the charge information of the system 10 that is a charge / discharge standard, and remotely controlled. can do.

In addition, the controller 50 transmits the amount and cost information for selling and purchasing the system 10 and power (electricity) to the system 10 through user information recognition, charges the cost, and automatically calculates the sales amount. Billing function related information to enable the system 10 can be transmitted or received.

In the above embodiment, the controller 50 is described as a separate configuration, but the controller 50 may be included in the power converter 30.

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

Referring to FIG. 2, the power converter 30 according to the embodiment may include a connection unit 31, a power storage unit 35, a power supply unit 37, and a converter 100.

The power converter 30 may be connected to the grid 10, the load 20, and the solar cell 40 in a three-phase five-wire manner.

The three-phase five-wire system transfers three-phase AC voltage to five wires. The five wires may be an R line, an S line, a T line, an N line, and an E line. The R line, S line and T line may be defined in any order. The five wirings are defined as R lines, S lines, T lines, N lines, and E lines in order from top to bottom. The N line is a neutral line, and the E line is a ground line.

Since the solar cell 40 is connected in a single phase, the solar cell 40 may be connected between the R line and the N line, between the S line and the N line, or between the T line and the N line.

The power converter 30 includes first to third power converters, wherein the first power converter is between the R line and the N line, the second power converter is between the S line and the N line, and the third power converter is the T line and the N line. Can be connected between the lines.

The connection part 31 of the power converter 30 may supply power to the first to third power converters by using the solar cell 40 to supply power to only one phase.

The connection part 31 may connect the solar cell 40 connected by the three-phase five-wire and the converter 100 connected in a single phase. The connection part 31 may connect the solar cell 40 connected by the three-phase five-wire with the converter 100 connected in a single phase, so that the solar cell 40 connected by the single phase does not depend on the system 10 when the power storage part 35 is charged. Since the battery 40 can be charged, power consumption of the system 10 can be reduced.

The connection part 31 may include a relay part 32 and a diode part 34.

The relay unit 32 may include first to third relays (Relay1 to Relay3). The first relay Relay1 is connected between the R line and the converter 100, the second relay Relay2 is connected between the S line and the converter 100, and the third relay Relay3 is connected to the T line. It may be connected between the converter (100). One end of the first to third relays Relay1 to Relay3 is electrically connected to an R line, a T line, and an S line, respectively, and the other end of the first to third relays Relay1 to Relay3 is connected to the converter 100. Can be connected in common.

The first to third relays Relay1 to Relay3 may be shorted or opened by the first to third control signals S1 to S3 from the controller 50, respectively.

The controller 50 receives the position where the solar cell 40 is connected and applies a control signal corresponding thereto. For example, when the solar cell 40 is connected between the R line and the N line, the first control signal S1 is applied at a high level to short-circuit the first relay Relay1, so that the R line and the converter are shorted. When the solar cell 40 is connected between the S line and the N line, the second control signal S2 is applied at a high level so that the second relay Relay2 is short-circuited. When the line is connected to the converter 100 and the solar cell 40 is connected between the T line and the N line, the third control signal S3 is applied at a high level to short-circuit the third relay Relay3. The R line may be connected to the converter 100.

In addition, the controller 50 may connect all of the first to third relays (Relay1 to Relay3) to connect the solar cell 40 and the converter 100 regardless of the position of the solar cell 40. have.

The diode unit 34 may be connected between the R, S, and T lines and the power supply unit 37. The diode unit 34 may rectify an AC voltage supplied from the R line, the S line, and the T line to supply the power to the power supply 37.

The diode unit 34 may include first to third diodes D1 to D3.

The first diode D1 is connected between the R line and the power supply 37 to rectify the AC voltage of the R line to supply the power to the power supply 37, and the second diode D2 is connected to the S line and the power supply ( 37), rectifies the AC voltage of the S line and supplies it to the power supply unit 37, and the third diode D3 is connected between the T line and the power supply unit 37 to supply the AC voltage of the T line. It can be rectified and supplied to the power supply 37.

AC voltages applied to the R, S, and T lines are waveforms having a phase difference of 120 ° from each other. When the waveform rectified by the diode unit 34 is commonly applied to the power supply unit 37, the waveform having a 120 ° phase is superimposed and supplied to the power supply unit 37 at a voltage close to DC.

The power supply unit 37 may generate a power supply voltage by dividing the voltage applied from the diode unit 34. The power supply 37 may be used as an initial power supply voltage by applying the power supply voltage to the control unit 50 and the converter 100. The voltage may be applied to the power supply 37 through the diode 34 to initially drive the controller 50 and the converter 100. In other words, the power supply unit 37 may drive the controller 50 generating the first to third control signals S1 to S3 through the voltage from the diode unit 34. Accordingly, a configuration for applying a separate initial power source to the controller 50 can be omitted, thereby simplifying the power converter 30.

The converter 100 may convert an AC voltage applied from the connection unit 31 into a DC voltage and apply the same to the power storage unit 35. The converter 100 may convert a DC voltage charged in the power storage unit 35 into an AC voltage and transmit the converted AC voltage to the connection unit 31. The voltage conversion direction of the converter 100 may be controlled by the controller 50.

The power storage unit 35 may be a battery. The power storage unit 35 stores the DC voltage transmitted from the system 10 through the converter 100, and transfers the stored DC voltage to the converter 100 according to a control signal from the controller 50. You can print

3 is a view showing a power conversion apparatus according to another embodiment.

The power converter 30 according to FIG. 3 includes an inrush prevention relay Relay4 and a resistor R between the relay unit 32 and the converter 100 as compared to the power converter 30 according to FIG. 2. It is the same except that.

Therefore, in describing FIG. 3, the same reference numerals are assigned to the same parts as those in FIG. 2, and detailed description thereof will be omitted.

Referring to FIG. 3, the power converter 30 according to another embodiment of the present invention may include a connection unit 31, a power storage unit 35, a power supply unit 37, and a converter 100.

The connection part 31 may include a relay part 32 including first to third relays (Relay1 to Relay3) and a diode part 34 including first to third diodes (D1 to D3). have.

The inrush prevention relay Relay4 and the resistor R may be electrically connected between the relay unit 32 and the converter 100. The inrush protection relay 4 and the resistor R may be connected in parallel between the relay unit 32 and the converter 100. One end of the inrush prevention relay Relay4 and the resistor R is connected to a contact to which the first to third relays Relay1 to Relay3 are commonly connected, and the other ends of the inrush prevention relay Relay4 and the resistor R. May be electrically connected to the converter 100.

When the relay unit 32 is turned on and the voltage is applied to the converter 100, the inrush prevention relay Relay4 and the resistor R are suddenly subjected to a high current to the converter 100 so that the converter 100 is turned on. It can prevent damage.

The inrush prevention relay Relay4 may be controlled by the fourth control signal C4 from the controller 50.

When the relay unit 32 is turned on, the controller 50 applies the fourth control signal C4 at a low level to control the resistance to be connected between the relay unit 32 and the converter 100. . The resistor R may attenuate the inrush current applied to the converter 100 when the relay unit 32 is turned on.

The controller 50 turns on the inrush prevention relay Relay4 by applying the fourth control signal C4 to a high level after a predetermined time after the relay unit 32 is turned on. The inrush prevention relay Relay4 electrically connects the relay unit 32 and the converter 100 after the inrush current flows, thereby reducing power consumption due to the resistance R during power transfer.

4 is a block diagram illustrating in detail the converter of the power changer according to the embodiment.

Referring to FIG. 4, the converter 100 of the power converter according to the embodiment may include a filter unit 110, a converter unit 12, and a booster unit 130.

The filter unit 110 is electrically connected to the connection unit 31, the booster unit 130 is electrically connected to the power storage unit 35, and the conversion unit 120 is the filter unit 110. ) And the booster 130 may be electrically connected.

The filter unit 110 may filter noise and surge voltage generated from the system 10 input through the connection unit 31 or the output of the converter 120 or the input AC power. The filter unit 110 may operate as a bidirectional filter.

The converter 120 is a bidirectional converter, and when the power storage unit 35 is charged from the system 10, rectifies an input AC power supply and smoothes the power to the booster 130. At the time of power generation of 35, the DC voltage of the power storage unit 35 may be converted into alternating current and transferred to the system 10 through the filter unit 110. In other words, the converter 120 may convert an AC voltage into a DC voltage and convert the DC voltage into an AC voltage.

The booster 130 may reduce the DC voltage supplied from the converter 120 to a level that the power storage unit 35 can store and transfer the DC voltage to the power storage unit 35. The booster 130 may boost the DC voltage supplied from the power storage 35 to the converter 120.

1: energy storage system
10: system
20: load
30: power inverter
31: connection
32: relay unit
34: diode
35: power storage
37: power supply
40: solar cell
50: control unit
60: switch
100: converter
110: filter unit
120: converter
130: pressure reducing unit

Claims (10)

delete delete delete A system for supplying power in a three-phase five-wire system including an R line, an S line, a T line, an N line, and an E line;
A load consuming the power;
A power converter for storing power from the system or supplying stored power to the load;
A control unit controlling to provide power to the load from the system or the power converter;
It includes a solar cell for supplying power to at least one of the grid, the load and the power converter,
The power converter,
A power supply unit generating a power supply voltage;
A connecting unit converting an AC voltage from the system into a single phase;
A power storage unit charging a voltage from the system; And
A converter for converting a voltage between the connection part and the power storage part,
The power converter includes a first power converter connected between the R line and the N line, a second power converter connected between the S line and the N line, and a third device connected between the T line and the N line. Including a power converter,
The solar cell is connected in a single phase between the R line and the N line, between the S line and the N line or between the T line and the N line,
The control unit may short-circuit a relay corresponding to the solar cell among the first to third relays to connect the converter selected from the R line, the S line, and the T line corresponding to the solar cell, and the converter.
The connecting unit supplies power to the first to third power converters through the solar cell which supplies power to only one phase selected from the three phase five wires, and the single phase with the solar cell connected to the three phase five wires. Connect the converter connected with
The connection unit may include a relay unit including first and third relays connected to each line of the three phases and the converter, and a diode unit including first to third diodes connected between each line of the three phases and the power supply unit. Including,
An inrush prevention relay and a resistor electrically connected between the connection portion and the power storage unit,
The inrush prevention relay and the resistor is connected in parallel between the relay unit and the converter,
One end of the inrush prevention relay and the resistor is connected to a contact to which the first to third relays are commonly connected, the other end of the inrush prevention relay and the resistor is electrically connected to the converter,
The controller controls the inrush prevention relay, and the relay unit is short-circuited to connect the resistor between the relay unit and the converter when a voltage is applied to the converter, and after the set time, between the relay unit and the converter. Connect inrush protection relay,
The power supply unit divides the voltage applied from the diode unit to generate the power supply voltage, and applies the power supply voltage to the controller and the converter to use as an initial voltage. The method of claim 4, wherein
And a switch connected between the grid and the load, wherein the switch is short-circuited to receive power from the grid and to open the switch to receive power from the power converter. delete delete delete delete delete

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