KR20150031060A - Power conditioning system - Google Patents

Abstract

The present invention relates to a power conditioning system which can protect internal components of the same when an over-current or an overvoltage is generated. According to an embodiment of the present invention, the power conditioning system includes: an energy storage part to be charged with a voltage supplied from a system; a conversion part to perform voltage conversion between the system and the energy storage part; and a control part to control the operation of the system, energy storage part, and conversion part. The control part detects an overvoltage or an over-current from the system, the energy storage part, or the conversion part and then controls the operation of the system, energy storage part, and conversion part.

Description

Power conditioning system

An embodiment relates to 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.

A power conditioning system (PCS) included in such an ESS device includes a conversion unit that receives system power and converts the DC power into a DC power, converts the received DC power into an AC power and transfers the AC power to the system side and the load side, And a control unit for controlling the switches of the system, the conversion unit, and the power storage unit.

The system, the conversion unit, and the power storage unit generate an overcurrent or an overvoltage during operation, thereby damaging the internal circuit of the power conversion apparatus.

The embodiment provides a power conversion device that can protect the internal configuration of the power conversion device when over-current or over-voltage occurs.

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 control unit for controlling operations of the system, the power storage unit, and the conversion unit, and the control unit controls an operation of the system, the power storage unit, and the conversion unit by detecting an overvoltage or an overcurrent of the system, the power storage unit, or the conversion unit.

The power conversion apparatus according to the embodiment may include a separate analog circuit in the control unit to stop the operation of the control unit when an overvoltage or an overcurrent occurs to protect the internal configuration of the power conversion device from an overcurrent or an overvoltage, So that the reliability of the product can be improved.

1 is a block diagram showing an energy storage system according to a first embodiment.
2 is a block diagram showing a power conversion apparatus according to the first embodiment.
3 is a circuit diagram showing a connection relationship between the power conversion apparatus and the system according to the first embodiment.
4 is a block diagram showing a control unit according to the first embodiment.
5 is a circuit diagram of the circuit protection unit according to the first embodiment.
6 is a circuit diagram of the circuit protection unit according to the second 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 showing an energy storage system according to a first embodiment.

Referring to FIG. 1, the energy storage system according to the first 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 the first embodiment.

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

The power inverter 30 may include a controller 100, a filter 110, a converter 120, a voltage-down converter 130, and a power storage 140.

The power conversion apparatus 30 stores the AC input power transmitted to the system 10 under the control of the controller 100 in the power storage unit 140 and controls the AC input power 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, and the power unit 150 to each configuration. The control unit 100 may control charge / discharge between the system 10 and the power storage unit 140.

The control unit 100 may control the operations of the filter unit 110, the conversion unit 120, the decompression unit 130, and the power supply unit 150. The control unit 100 can control the operation of the power conversion device 30 by controlling the switches included in each configuration of the power conversion device 30. [

The control unit 100 senses current and voltage of each configuration of the power conversion apparatus 30 and controls the power conversion apparatus 30 so that when an overcurrent or an overvoltage is applied to each configuration of the power conversion apparatus 30, The operation can be stopped. The control unit 100 senses the current and voltage of the system 10, the voltage-decreasing unit 130, and the power supply unit 150 to determine the overcurrent or overvoltage when the current or voltage is equal to or greater than the reference current or the reference voltage, It is possible to stop the operation of the power conversion device 30 and protect the internal configuration of the power conversion device 30. [ The power conversion device 30 may stop the operation of the power conversion device 30 by opening a switch included in the power conversion device 30 when the overcurrent or overvoltage is determined.

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 .

3 is a circuit diagram showing a connection relationship between the power conversion apparatus and the system according to the first embodiment.

Referring to FIG. 3, the power conversion apparatus according to the first embodiment may include a filter unit 110, a conversion unit 120, a step-up / down unit 130, and a power storage unit 140.

The system 10 may be electrically connected to the filter unit 110.

The control unit 110 can sense the voltages at both ends of the system 10 and sense the current flowing between the system 10 and the filter unit 110.

The filter unit 110 may include first to fourth inductors L1 to L4 and a capacitor C. [

The first inductor L1 may be connected in series with the third inductor L3 and the second inductor L2 may be connected in series with the fourth inductor L4. The capacitor C may connect between the first inductor L1 and the third inductor L3 and between the second inductor L2 and the fourth inductor L4.

The filter unit 110 including the first to fourth inductors L1 to L4 and the capacitor C is capable of generating noise and static electricity that may be generated when AC voltage is stored from the system 10 to the power storage unit 140, And filter static electricity that may be generated when a voltage is output from the power storage unit 140 to the system 10. [

The conversion unit 120 may include first to fourth transistors Q1 to Q4, first to fourth diodes D1 to D4, and a connection capacitor Clink.

The first to fourth transistors Q1 to Q4 and the first to fourth diodes D1 to D4 may form a bridge between the first and second nodes N1 and N2.

The first to fourth transistors Q1 to Q4 may be controlled by the first to fourth signals S1 to S4, respectively. The first to fourth transistors Q1 to Q4 may be connected in parallel with the first to fourth diodes D1 to D4, respectively. The first to fourth 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. And may be connected between the first node N1 and the fourth node N4.

The third transistor Q3 and the third diode D3 are connected between the second node N2 and the third node N3 and the fourth transistor Q4 and the fourth diode D4 are connected between the second node N2 and the third node N3, And may be connected between the second node N1 and the fourth node N4.

The third node N3 is a contact point between the third inductor L3 and the first and third transistors Q1 and Q3 and the fourth node N4 is a node between the fourth inductor L4 and the fourth inductor L4, And may be a contact point between the second and third transistors Q2 and Q4.

The first and fourth transistors Q1 and Q4 operate simultaneously and the second and third transistors Q2 and Q3 operate simultaneously so that the DC voltages of the first and second nodes N1 and N2 are alternately Voltage to the third and fourth nodes N3 and N4 or to convert the AC voltage of the third to fourth nodes N3 to N4 into the DC voltage, N1, N2).

The first to fourth diodes D1 to D4 serve as protection elements for the first to fourth transistors Q1 to Q4 to prevent a 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-up / down unit 130 and transmits the DC voltage to the first to fourth transistors Q1 to Q4. The first to fourth transistors Q1 to Q4 And smoothes the voltage input from the voltage-up / down unit 130 to the boost /

The controller 100 may sense the current and the voltage of the converting unit 120. The controller 100 may sense a voltage across the connection capacitor Clink. The controller 100 may sense a current flowing from the converting unit 120 to the voltage-rising /

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 two transistors Qa and Qb of the boost / depressurization unit 130 may also be controlled by the control unit 100.

The controller 100 may sense a voltage across the power storage unit 140. The controller 100 may sense a current between the power storage unit 140 and the boost /

4 is a block diagram showing a control unit according to the first embodiment.

Referring to FIG. 4, the control unit 100 according to the first embodiment receives the voltage and current shown in FIG. 2 as a sensing signal Sen, and generates and outputs a control signal con through the sensing signal Sen.

The control unit 100 may include a signal processing unit 101, a level shifter 103, and a circuit protection unit 105.

The signal processing unit 101 may receive the sensing signal Sen and may calculate the sensing signal Sen to output a line control signal precon. The sensing signal (Sen) may be a current and a voltage of each configuration of the power conversion device (30). The sensing signal Sen may be a current and a voltage of the system 10, the conversion unit 120, and the power storage unit 140. The sensing signal Sen may be the voltage and current shown in FIG.

The line control signal precon may be a signal for outputting a voltage and a current of a predetermined level by controlling each configuration of the power conversion device 30. [ The signal processing unit 101 receives the sensing signal Sen and can calculate the sensing signal Sen to output the line control signal precon. The line control signal precon may be a pulse width modulation (PWM) signal.

The level shifter 103 receives the line control signal precon and outputs a control signal con. The level shifter 103 may amplify the line control signal precon and output it as a control signal con.

The control signal con may serve to stabilize the output of the power conversion device 30. [ The control signal con controls on / off of the transistors of the power conversion device 30 to control the current and voltage of each configuration of the power conversion device 30 at a constant level. The control signal con may control the conversion unit 120 and the step-up / down unit 130. The control signal con controls on-off of the first to fourth transistors Q1 to Q4 of the conversion unit 120 and the two transistors Qa and Qb of the voltage-down unit 130, The current and voltage of each configuration of the converting apparatus 30 can be controlled to a certain level. The control signal con may be a PWM signal.

The circuit protection unit 105 receives the sensing signal Sen and controls the level shifter 103 through the sensing signal Sen. The circuit protection unit 105 may control whether the level shifter 103 outputs the control signal con by the sensing signal Sen.

The circuit protection unit 150 may cut off the output of the control signal con of the level shifter 103 when the voltage or current input by the sensing signal Sen is determined to be an overvoltage or an overcurrent.

5 is a circuit diagram of the circuit protection unit according to the first embodiment.

Referring to FIG. 5, the circuit protection unit 105 according to the first embodiment may include first to nth protection blocks 105a to 105n.

The first to nth protection blocks 105a to 105n may be connected to the level shifter 103, respectively.

The first to nth protection blocks 105a to 105n may include a buffer 107 and a comparator 109, respectively. Since each of the first to nth protection blocks 105a to 105n includes the same configuration, only the operation of the first protection block 105a will be described as an example.

The buffer 107 and the comparator 109 may be an operational amplifier (OP-AMP).

The first protection block 105a receives the first sensing signal Sen1. The first sensing signal (Sen1) may be input to the non-inverting terminal of the buffer (107). The buffer 107 may transmit the first sensing signal Sen1 to the comparator 109. [

The first reference voltage ref1 may be input to the inverting input terminal of the comparator 109 and the first sensing signal Sen1 may be input to the noninverting input terminal of the comparator 109. [ The comparator 109 compares the first reference voltage Vref1 with the first sensing signal Sen1 and outputs a high level when the first sensing signal Sen1 is greater than the first reference voltage Vref1 The operation of the level shifter 103 is stopped. The first reference voltage Vref1 may be an overvoltage reference voltage. The first protection block 105a may stop the operation of the level shifter 103 when the first sensing signal Sen1 is equal to or higher than the overvoltage reference voltage.

The first protection block 105a may further include a diode D1 connected between the non-inverting input terminal and the output terminal of the comparator 109. [ The diode D1 may operate as a latch.

The second sensing block Sen2 is applied to the second protection block 105b to compare the second sensing signal Sen2 with the second reference voltage Vref2 to determine whether the second sensing signal Sen2 is overvoltage.

The first to nth protection blocks 105a to 105n can control the operation of the level shifter 103 by determining overvoltage or overcurrent of each sensing signal Sen. The operation of the level shifter 103 can be stopped when any one of the first to nth sensing signals Se1 to Senn is determined to be an overvoltage or an overcurrent.

In FIG. 3, three voltages and three currents are sensed and input to the controller 100. Six sensed signals are input, and six protection blocks are required, but the numbers are not limited.

The circuit protection unit 105 according to the first embodiment forms a separate circuit in addition to the signal processing unit 101 to control the operation of the level shifter 103 so that the signal processing unit 101, It is possible to effectively protect each configuration of the power conversion device 30 regardless of whether the power conversion device 30 is operated or not. In other words, even if there is an error in the operation of the signal processing unit 101, the power conversion apparatus 30 can be protected from the overcurrent, and the reliability of the product can be improved.

In addition, the circuit protection unit 105 is constituted by an analog circuit having relatively high slew rate, so that the power conversion apparatus 30 can be stably protected.

6 is a circuit diagram of the circuit protection unit according to the second embodiment.

The circuit protection unit according to the second embodiment is the same as the circuit protection unit according to the first embodiment except that the comparator and the buffer are formed by a simpler circuit. Therefore, in explaining the second embodiment, detailed description of the configuration common to the first embodiment will be omitted.

Referring to FIG. 6, the circuit protection unit 205 according to the second embodiment may include first through n-th divided portions 208a through 208n and a comparator 209.

The first to n-th divided parts 208a to 208n may each include two voltage dividing resistors and one diode. The first to nth divided parts 208a to 208n may include a first voltage dividing resistor Ra, a second voltage dividing resistor Rb, and a voltage dividing diode Dk.

Since the first through n-th divided parts 208a through 208n include the same configuration, only the connection relationship of the first divided part 208a will be described by way of example.

The first voltage dividing unit 208a includes a first voltage dividing resistor R1a and a second voltage dividing resistor R1b connected in series. A voltage dividing diode Dk may be connected between the first and second voltage dividing resistors R1a and R1b.

The first sensing signal Sen1 is applied to the first voltage dividing resistor R1a and the voltage of the first voltage dividing resistor R1a and the second voltage dividing resistor R1b is applied to the voltage dividing diode Dk, The first sensing signal Sen1 is changed.

The first through n-th sensing signals Sen1 through Senn may be applied to the first through n-th divided portions 208a through 208n, respectively. The first to nth sensing signals Sen1 to Senn may be applied to one end of the first voltage dividing resistor Ra of the first to nth divided parts 208a to 208n. The first to nth divided portions 208a to 208n may divide the first to nth sensing signals Sen1 to Senn and output the divided signals to the comparator 209. [ The first through n-th divided parts 208a through 208n may have different partial pressure resistance ratios. The first to the n-th divided parts 208a to 208n may have a ratio of the first and second voltage dividing resistors Ra and Rb, respectively.

The first through n-th divided portions 208a through 208n may be connected to the non-inverting input of the comparator 209. [ The first through n-th divided portions 208a through 208n may be connected in parallel to the non-inverting input of the comparator 209.

A reference voltage ref may be applied to the inverting input of the comparator 209. The first through n-th divided parts 208a through 208n may have a voltage-divided resistance ratio corresponding to the reference voltage ref. That is, since the voltages or currents applied to the first to the n-th sensing signals Sen1 to Senn are input as the current and voltage of FIG. 3, respectively, the first to nth divided portions 208a to 208n The voltage-versus-resistance ratio is set so as to match the voltage and current levels of the first to the n-th sensing signals Sen1 to Senn with one comparator 209 and one reference voltage ref can do.

For example, if a voltage of 5V is applied to the first sensing signal Sen1, an overvoltage boundary value of the first sensing signal Sen1 is 10V, and a reference voltage ref is 1V, The ratio of the first and second voltage dividing resistors R1a and R1b is set to 9: 1, and the first sensing signal Sen1 is magnified in a 1/10 ratio by a voltage division law Inverted terminal of the comparator 209. In this case, Since 0.5 V is applied to the non-inverting terminal of the comparator 209, the comparator 209 judges that the overvoltage has not been reached.

When the voltage of 22V is applied to the second sensing signal Sen2 and the overvoltage boundary value of the second sensing signal Sen2 is 20V and the reference voltage ref is 1V, 208b sets the ratio of the first and second voltage dividing resistors R2a and R2b to 19: 1 and resets the second sensing signal Sen2 to 1/20 by the voltage division law Inverting terminal of the comparator 209. [ It is determined that the overvoltage exceeding the reference voltage ref is reached because 1.1 V is applied to the noninverting terminal of the comparator 209 and the comparator 209 stops the operation of the level shifter 203 .

In FIG. 3, since three voltages and three currents are sensed and input to the controller 100, six sensed signals are input and six voltage dividers are required, but only one comparator is required.

The circuit protection unit 205 according to the second embodiment controls the operation of the level shifter 203 by constituting a separate circuit in addition to the signal processing unit 101 so that when the overvoltage or overcurrent occurs, It is possible to effectively protect each configuration of the power conversion device 30 regardless of whether the power conversion device 30 is operated or not. In other words, even if there is an error in the operation of the signal processing unit 101, the power conversion apparatus 30 can be protected from the overcurrent, and the reliability of the product can be improved.

In addition, the circuit protection unit 205 is constituted by an analog circuit having a relatively high slew rate, so that the power conversion apparatus 30 can be stably protected.

Since the circuit protection unit 205 according to the second embodiment determines whether an overvoltage or an overcurrent occurs using one reference voltage with one comparator 209, the circuit protection unit 205 may simplify the structure of the circuit protection unit 205 It is possible to reduce the size, and the manufacturing cost can be reduced.

The features, structures, effects and the like described in the foregoing embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments may be combined or modified in other embodiments by those skilled in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiments may be modified and implemented. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

10: System
20: Load
30: Power converter
40: Switch
100:
101: Signal processor
103: Level shifter
105: Circuit protection
110:
120:
130:
140:

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 control unit for controlling operations of the system, the power storage unit, and the conversion unit,
Wherein the control unit detects an overvoltage or an overcurrent of the system, the power storage unit, or the conversion unit to control the operation of the system, the power storage unit, and the conversion unit. The method according to claim 1,
Wherein,
A signal processing unit receiving a current and a voltage of the system, the power storage unit or the conversion unit as a sensing signal and generating a control signal; And
And a circuit protection unit for determining whether the control unit is operated through the sensing signal. 3. The method of claim 2,
Wherein the circuit protection unit detects the overcurrent or overvoltage by comparing the sensing signal with a reference voltage. 3. The method of claim 2,
Wherein,
And a level shifter for amplifying the control signal from the signal processing unit and supplying the amplified control signal to the system, the power storage unit, and the conversion unit. 5. The method of claim 4,
The circuit protection unit includes:
And stops the operation of the level shifter when the sensing signal is equal to or higher than the reference voltage. 3. The method of claim 2,
Wherein the circuit protection unit is an analog circuit. 3. The method of claim 2,
Wherein the circuit protection portion includes a plurality of protection blocks,
Wherein the plurality of protection blocks compare the respective sensing signals with a reference voltage to determine whether to operate the control unit. 8. The method of claim 7,
Wherein the plurality of protection blocks each include a buffer and a comparator. 3. The method of claim 2,
The circuit protection unit includes:
A plurality of voltage dividing portions for dividing the respective sensing signals; And
And a comparator for comparing the sensing signal divided from the voltage divider with a reference voltage to determine whether the control unit operates. 10. The method of claim 9,
Wherein the plurality of voltage dividing units change magnitudes of the sensing signals at different ratios.

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