KR101144737B1 - Energy storage system having uninterruptible power supply and pwm correcting method thereof - Google Patents

Abstract

PURPOSE: An energy storage system and a pulse width modulation correcting method are provided to improve power factor of system electricity, harmonic wave, and low voltage at the same time by correcting a pulse width modulation signal of a bidirectional converter device based on a current and voltage supplied in system. CONSTITUTION: A bidirectional converter device(30) changes an AC power supply of a system(10) into a DC power supply and offers the DC power supply to an power accumulating part(33). A converter(35) changes the DC power supply saved in the power accumulating part into the AC power supply and transfers the AC power supply to the system. A PWM controller(Pulse Width Modulation) creates a PWM signal for controlling operation of the converter. A controller(40) corrects the PWM signal based on a power factor correction command a harmonic wave correction command. The controller comprises a PLL(Phase Lock Loop) part, a current monitoring part, and a correction control part.

Description

Ess device having a power failure function and a PSM correction method according to the present invention {Energy storage system having uninterruptible power supply and PWM correcting method}

The present invention relates to an ESS having a power failure function and a PWM correction method according thereto, and more particularly, a PWM signal for controlling the operation of a bidirectional converter based on an external power factor correction command, a harmonic correction command, and an instantaneous unit power factor control. The power factor, harmonics and low voltage of the grid power can be improved at the same time, and the uninterruptible power supply function can be executed by providing the discharge power of the bidirectional converter device to the load side by disconnecting the grid side and the load side during power failure. To one device and method.

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.

Such an ESS device includes a converter that receives 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, and a power storage unit that supplies the DC power of the converter to the converter. It includes a PWM control unit for controlling the operation of each component.

In the ESS device having such a conventional bidirectional converter device, the grid-side AC power distorts the AC power when using non-linear loads or rectifying the load equipment rectified by phase control, causing a failure in the equipment connected to the grid, There is no compensating function for harmonics that severely disturb these loads. Therefore, a separate harmonic compensation device and a non-interruptible power supply to supply high-quality power to the load side are separately attached to the grid side.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a power factor correction command supplied by the current and voltage of the grid side and the active power of the grid side in a PWM converting bidirectional converter device. A power failure function capable of simultaneously improving the power factor, low voltage, and harmonics of the system-side AC power supply to maximize energy efficiency by correcting the PWM signal of the bidirectional converter device based on the harmonic correction command and the instantaneous unit power factor control command. An object of the present invention is to provide an Energy Storage System (ESS) device and a PWM correction method accordingly.

Another object of the present invention is to provide a simple configuration by separately adding a switch to supply the discharge power of the bidirectional converter device to the load side by interrupting the PWM rectification type bidirectional converter device and the load side and the grid side connection. The present invention aims to provide an ESS device and a PWM correction method with a non-interruption function that can stably protect the system side and the load side in case of power failure, and improve efficiency, reliability, and stability.

According to an aspect of the present invention for achieving the above object, there is provided an ESS device having a power failure function, such an apparatus,

In an ESS device having an uninterrupted function of charging and discharging grid-side power by a bidirectional converter device based on a PWM signal, and transferring the power to a load side in the event of power failure,

The bidirectional converter device,

A converter which receives grid-side AC power and converts it into DC power and outputs it, converts the received DC power into AC power and transmits it to the load side and the grid side, a power storage unit for storing the DC power of the converter, and the power storage unit. It includes a PWM control unit for generating and supplying a PWM signal for controlling the operation of the converter according to the determined phase angle of the stored DC power,

And a control unit for correcting the PWM signal based on a power factor correction command, a harmonic correction command, and an instantaneous unit power factor control command supplied from the grid-side power and the grid-side active power output from the bidirectional converter device. .

The control unit,

A phase lock loop (PLL) unit for receiving a voltage on one of the grid-side AC powers to derive a synchronous phase angle;

A current monitoring unit configured to monitor a current pattern of the grid-side power based on the synchronous phase angle of the PLL unit to generate a d-axis instantaneous current detection value and a q-axis instantaneous current detection value of the synchronous coordinate system, respectively;

Active current that is the d-axis current reference value of the synchronous coordinate system to remove distortion of power factor, harmonics, or low voltage based on power factor correction command, harmonic correction command, and instantaneous power factor control command supplied from externally supplied active power A correction control unit for generating an instantaneous current command value and an reactive current instantaneous command value, which are q reference current values, respectively;

The error instantaneous of the d-axis is calculated by calculating an error for each of the d-axis current reference value and the q-axis current reference value or the q-axis current reference value of the correction controller and the d-axis instantaneous current detection value and the q-axis instantaneous current detection value of the current monitoring unit. An error instantaneous current generation unit for generating a current value and an error instantaneous current value of the q-axis, respectively;

An instantaneous voltage reference value generation unit for deriving an instantaneous voltage reference value of the d-axis and an instantaneous voltage reference value of the q-axis based on a proportional integral expression formula for the error instantaneous current value of the d-axis and the error instantaneous current value of the q-axis, respectively; ,

The instantaneous error voltage reference value of the d-axis and the instantaneous error voltage reference value of the q-axis are converted into the α-axis instantaneous voltage reference value and the β-axis instantaneous voltage reference value of the stationary coordinate system based on the synchronization phase angle. A conversion unit for matching the α-axis instantaneous voltage reference value with the β-axis instantaneous voltage reference value,

And a PWM correction generator for deriving a PWM correction signal for each phase based on the α-axis instantaneous voltage reference value and the β-axis instantaneous voltage reference value of the conversion unit, and correcting the PWM signal of the PWM control unit with the derived PWM correction signal. It would be desirable to.

Here, the correction control unit,

Based on the AC power of the grid for each phase, a low voltage correction algorithm that determines whether a segment has been generated and generates a reactive current instantaneous command value, which is a q-axis current reference value, to remove distortion of low voltage components when the segment is generated, A voltage compensation module,

A power factor correction module for receiving a power factor correction command and an instantaneous unit power factor control command supplied from the active power of the grid side and executing a power factor correction algorithm for correcting the power factor component included in the grid side power;

 Harmonics that execute harmonic correction algorithms that control harmonic components (harmonic components) for multiple orders included in grid-side current based on harmonic correction commands supplied from the grid-side active power to correct harmonic components for grid-side power. It would be desirable to include a calibration module.

Here, the correction control unit,

From the voltage of each phase supplied to the grid side power, it is determined whether a segment of grid side power has occurred,

As a result of the determination, when the segment is generated, it may be desirable to generate the reactive current instantaneous command value, which is the q-axis current reference value, by performing the low voltage correction through the low voltage correction algorithm.

The correction control unit,

If it is determined that no segment is generated, it is determined whether the battery is in the charging or discharging mode, and if it is determined that the battery is being discharged, the power factor correction algorithm is executed based on a power factor correction command generated from an external power source. It may be desirable to provide an instantaneous current instantaneous setpoint and a reactive current instantaneous setpoint that is a q-axis current reference value.

The correction control unit,

As a result of the determination, when not in charge and discharge, the instantaneous current instantaneous value and the reactive current instantaneous value, which are the d-axis current reference value and the q-axis current reference value, are used to detect the harmonic components included in the grid-side current supplied from the outside to remove the detected harmonics. It would be desirable to be provided to generate a reference value.

The correction control unit,

It is preferable to be provided to generate a switch signal to determine whether the outage based on the AC power supplied from the system side to cut off the connection between the system side and the load in the event of a power failure to prevent the power of the system side from being transferred to the load side. something to do.

On the other hand, the ESS device having a power failure function,

It may be preferable to further include a switch unit which is switched to the off state in the event of a power failure according to the switching signal of the correction controller to cut off the connection between the grid side and the load side and supply discharge power of the bidirectional converter device to the load.

According to one aspect of the present invention for achieving the above object, there is provided a method of electrostatic free power, such a method,

Receiving the grid-side power from the correction control unit and determining whether a segment for the voltage of each phase of the received grid-side power has occurred;

When the segment is generated, a PWM signal for controlling the operation of a bidirectional converter device that executes a low voltage correction algorithm to generate an instantaneous current instantaneous command value, which is a q-axis current reference value, and transfers the power generation side power to the grid side power based on the instantaneous current instantaneous current command value. It characterized in that it comprises a step of correcting.

In the above method, when no segment is generated, the power storage unit of the bidirectional converter device determines whether it is charging or discharging, and when charging is being performed, the power factor correction algorithm is executed to invalidate the instantaneous current instantaneous command value, which is the d-axis current reference value, and the q-axis current reference value. It may be desirable to further include the step of correcting the PWM signal based on the active current instantaneous command value and the reactive current instantaneous command value generated by generating a current instantaneous command value.

The method may be configured to execute a harmonic correction algorithm based on the current of the grid-side power received when it is determined not to be in charge and discharge to generate an active current instantaneous command value, which is a d-axis current reference value, and an reactive current instantaneous command value, which is a q-axis current reference value. It may be desirable to further include correcting the PWM signal based on the generated active current instantaneous command value and the reactive current instantaneous command value.

As described above, the ESS device having a power failure function and the PWM correction method according to the present invention, the PWM signal of the bidirectional converter device based on the current and voltage supplied from the grid side in the PWM converting bidirectional converter device By improving the power factor, low voltage and harmonics included in the grid-side power, the energy efficiency can be improved to the maximum, and the discharge power of the bi-directional converter device is provided to the load-side by cutting off the grid-side and load-side connection in case of power failure. By adding a separate switch, a simple configuration can effectively and reliably protect the load side in case of power failure, and improve efficiency, reliability, and stability.

The following drawings attached in this specification are illustrative of the preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.
1 is a diagram showing the configuration of an ESS device according to an embodiment of the present invention.
2 is a view illustrating in detail the configuration of the controller shown in FIG.
3 is a block diagram illustrating a configuration of a correction controller illustrated in FIG. 2.
4 is a flowchart illustrating a PWM correction process of an ESS device according to another embodiment of the present invention.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like elements.

1 is a block diagram showing the configuration of an ESS device according to an embodiment of the present invention, FIG. 2 is a diagram showing in detail the configuration of the control unit shown in FIG. 1, and FIG. 3 is a configuration of the compensation control unit shown in FIG. Is shown.

As shown in the figure, the ESS device according to the present invention includes a bidirectional converter device 30 including a grid side 10, a converter 35 and a power storage unit 33, and a PWM control unit 37, and a switch unit. 70, a control unit 40, and a load 50.

The bidirectional converter device 30 receives the AC power from the system side 10, converts the power into DC power, provides the power storage unit 33, and converts the DC power stored in the power storage unit 33 into AC power. And a PWM control unit 37 for generating and supplying a PWM signal for controlling the operation of the converter 35 according to the synchronous phase angle of the AC power of the system side 10. .

In addition, the control unit 40 of the ESS apparatus, the power factor correction command, harmonic correction command supplied from the grid-side power (ia, ib, ic, Va, Vb, Vc) and the active power output from the converter 35 And correct the PWM signal based on instantaneous unit power factor control.

Here, the control unit 40 is a PLL (Phase Lock Loop) unit 41 which receives the AC power supplied from the system side 10 to derive a synchronous phase angle, and the synchronization of the PLL unit 41. A current monitoring unit 42 for monitoring a current pattern of power of the grid side 10 based on a phase angle to generate a d-axis instantaneous current value and a q-axis instantaneous current value in a synchronous coordinate system, respectively; Active current instantaneous value which is the d-axis current reference value in the synchronous coordinate system for removing distortion on power factor, harmonics, and low voltage based on power factor correction command, harmonic correction command, and instantaneous unit power factor control based on the active power of 10). A correction control unit 43 for generating an instantaneous power instantaneous command value that is a reference value and a q-axis current reference value, a d-axis current reference value and a q-axis current reference value of the correction control unit 43, and an d-axis instantaneous current of the current monitoring unit, respectively. Current detection An instantaneous error current generation unit 44 which calculates an error for each of the value and the q-axis instantaneous current detection value and generates an instantaneous error current value of the d-axis and an q-axis instantaneous error current value, respectively, and the d-axis instantaneous error current value and an instantaneous voltage reference value generation unit 45 for deriving a d-axis voltage reference value and a q-axis voltage reference value from a proportional integral relationship formula for each of the q-axis instantaneous error current values, and the instantaneous phase based on the synchronous phase angle A conversion unit 46 that converts the d-axis instantaneous error voltage reference value and the q-axis instantaneous error voltage reference value of the voltage reference value generator 45 into the α-axis reference value and the β-axis reference value of the stationary coordinate system, and the conversion And a PWM correction generator 47 for deriving a PWM correction value for each phase based on the α-axis reference value and the β-axis reference value of the unit 46 and correcting the PWM signal of the inverter device with the derived PWM correction value. do.

That is, the control unit 40 is the d-axis instantaneous current value and the q-axis instantaneous current value for the AC power of the grid side 10 and the d-axis current reference value generated to correct the low voltage, power factor, and harmonics And a PWM correction signal for correcting a power factor, a low voltage, or a harmonic component with respect to AC power supplied from the grid side 10 based on the q-axis current reference value, and the generated PWM correction signal is a bidirectional converter device. 30 is supplied to the PWM control unit 37.

Based on the PWM signal corrected according to the PWM correction signal of the control unit 40, the AC power of the rectified system side 10 is transmitted to the load side 50 with a complete sine wave.

In addition, the correction control unit 43 determines whether a segment is generated based on the system-side power for each phase, and when the segment is generated, a reactive current instantaneous value which is a q-axis current reference value for removing distortion of a low voltage component. A low voltage correction module 431 that executes a low voltage correction algorithm for generating a setpoint, and a power factor correction command and an instantaneous unit power factor control command supplied from the grid side active power are supplied to the grid side 10 power. A power factor correction module 433 for executing a power factor correction algorithm for correcting the power factor component and a harmonic correction module 435 for executing a harmonic correction algorithm for detecting and correcting harmonics included in the system-side effective current.

That is, the correction control unit 43 determines whether a segment of the grid-side power is generated from the voltage of each phase supplied to the grid-side power, and when the segment is generated as a result of the determination, low voltage correction is performed through a low voltage correction algorithm. To generate a reactive current instantaneous reference value that is a q-axis current reference value.

In addition, the correction control unit 43 determines whether the charge discharge mode of the power storage unit 33 when no segment is generated as a result of the determination, and executes the power factor correction algorithm when the charge is discharged as a result of determination, and is supplied from the outside. And a reactive current instantaneous command value, which is a d-axis current reference value, and an reactive current instantaneous command value, which is a q-axis current reference value, based on a power factor correction command and an instantaneous unit power factor control command generated from power.

The correction control unit 43 detects harmonics from the grid-side current supplied from the outside when the power storage unit 33 determines that the current is not being charged and discharged. The instantaneous current instantaneous reference is a d-axis current reference value for removing the detected harmonics. And a reactive current instantaneous reference value that is a value and a q-axis current reference value.

Here, the low voltage correction module 431 receives and amplifies the AC power delivered from the inverter device 10 to the grid side, and then compensates for the amplified impedance and the low voltage component of the grid-side AC power reference value. Create

In addition, the power factor correction module 433 and the harmonic correction module 435, the grid-side active power is based on the voltage and current, the d-axis instantaneous current reference value and the q-axis instantaneous current reference to compensate for the voltage component, power factor, and harmonic components Generate each value.

The low voltage correction module 431 of the correction control unit 43 or the q-axis current reference value of at least one or more of the power factor correction module 433 and the harmonic correction module 435 or the d-axis current reference for power factor correction and harmonic correction. A value and a q-axis current reference value are generated and provided to the error instantaneous current generation unit 44.

On the other hand, the correction control unit 43 is provided to generate a switching signal for intermittent power supply supplied from the bidirectional converter device 30 to the system side 10 during a power failure.

In addition, the ESS device according to the embodiment of the present invention, the system side to provide the discharge power of the bi-directional converter device 30 to the load side 50 at the time of power failure based on the switching signal supplied from the correction control unit 43 It further comprises a switch unit 70 for blocking the connection of the 10 and the load side 50.

That is, in the normal state in which the power failure does not occur, the switch unit 70 is switched on so that the power of the grid side 10 is rectified through the bidirectional converter device 30 and is simultaneously provided to the load side 50. Within 150 msec, the switch unit 70 is switched off to cut off the connection between the grid side 10 and the load side 50 to convert the discharge power of the power storage unit 33 charged with the grid side 10 power. Supply to the load side 50 through 35).

Therefore, the switch unit 70 is a switch for controlling the connection between the system side 10, the bidirectional converter device 30, and the load side during power failure, and the power storage unit 33 through the converter 35 when the switch is in the on state. ) And the system power is supplied to the load side, and the charge and discharge unit for discharging the charging power through the converter 35 to supply to the load side when the switch is in the off state. In addition, the load 50 may include a non-static power supply.

According to this configuration, the converter 35 of the bidirectional converter device 30 is provided to the power storage unit 33 after converting the AC power of the grid side 10 to DC power and then converted DC power. In addition, the converter 35 converts the power of the power storage unit 33 into the AC power required by the system 10 and transfers the power of the power storage unit 35 to the system side 10 and the load side 50. do.

At this time, the PWM control unit 37 generates a PWM signal for controlling the rectifying operation of the converter 35 on the basis of the alternating current of the grid side 10 to provide to the converter 35.

In addition, in order to compensate for the low voltage, power factor, and harmonic components based on the grid-side power rectified by the bidirectional converter device 30, the control unit 40 receives an AC power from the grid-side 10 to receive an external power supply. A PWM correction signal for correcting the PWM signal is generated and provided to the PWM control unit 37 based on the power factor correction command, the harmonic correction command, and the instantaneous unit power factor control command.

A series of processes for generating the PWM correction signal in the control unit 40 to compensate for the low voltage, power factor, and harmonic components in the bidirectional converter device 30 will be described in more detail with reference to FIG. 2.

First, the PLL section 41 of the control section 40 generates a synchronous phase angle based on the AC voltage supplied from the grid side 10, and the synchronous phase angle is provided to the current monitoring section 42.

The current monitoring unit 42 generates an d-axis instantaneous current detection value and a q-axis instantaneous current detection value by monitoring an alternating current for each phase supplied from the grid side 10 based on the received synchronous phase angle. The instantaneous d-axis instantaneous current detection value and the q-axis instantaneous current detection value are provided to the error instantaneous current generation unit 44.

On the other hand, the correction control unit 43 provided with the power factor correction command, the harmonic correction command, and the instantaneous unit power factor control based on the active power of the system side 10 receives the received power factor correction command, the harmonic correction command, and the instantaneous unit power factor. Based on the control, the instantaneous current instantaneous command value and the reactive current instantaneous command value, which are the d-axis current reference value and the q-axis current reference value, are used to correct the power factor, harmonics, and low voltage components included in the AC power supplied from the grid side 10. The generated d-axis current reference value and the q-axis current reference value are provided to the error instantaneous current generator 44.

Here, the instantaneous current instantaneous command value, which is the q-axis current reference value, or the active current instantaneous command value, which is the d-axis current reference value, and the reactive current instantaneous value, which is the q-axis current reference value, are used to correct power factor, harmonics, and low voltage based on the grid-side active power. A series of processes to generate will be described with reference to FIG.

FIG. 4 is a flowchart illustrating an operation process of the correction control unit 43 illustrated in FIG. 2, and more specifically describes a PWM correction process according to another embodiment of the present invention.

First, the correction control unit 43 determines whether a segment is generated from the grid-side power received through the step 101 (step 103), and when the determination results, the low voltage correction module of the correction control unit 43 is generated. The low voltage correction algorithm of 431 is executed, and then, through step 105, a reactive current instantaneous command value that is a q-axis current reference value is generated (step 107). Here, the low voltage correction algorithm is a well-known technique well known by those skilled in the art, and a detailed description thereof will be omitted.

In addition, when no segment is generated in the step 103, the correction controller 43 determines whether the power storage unit 33 is being charged or discharged (step 109), and the power storage unit 33 charges as a result of the determination. In the case of discharging, the power factor correction algorithm of the power factor correction module 433 for power factor correction based on the power factor correction command and the instantaneous unit power factor control command supplied from the active power is executed (step 111), and the instantaneous current instantaneous setpoint which is the d-axis current reference value and A reactive current instantaneous setpoint which is a q-axis current reference value is generated (step 113). The power factor correction algorithm is a well-known technique well known by those skilled in the art, and a detailed description thereof will be omitted.

On the other hand, the correction control unit 43 proceeds to step 115 when not in charge and discharge in step 109 and based on the harmonic correction command generated from the active power and the instantaneous unit power factor control, the harmonics included in the grid-side current A harmonic correction algorithm for detecting and removing is executed (step 117), and then the harmonic correction algorithm generates an active current instantaneous reference value, which is a d-axis current reference value, and a reactive current instantaneous reference value, which is a q-axis current reference value, for removing harmonic components. (Step 119).

That is, when the non-linear load current included in the active power is detected, the instantaneous and reactive current instantaneous command values are generated based on the harmonic components minus the fundamental wave components, and the PWM signal is corrected by the generated effective and reactive current instantaneous command values. Harmonic component is removed. Since the harmonic correction algorithm is a well-known technique well known by those skilled in the art, a detailed description thereof will be omitted.

The instantaneous current instantaneous command value, which is the q axis current reference value for removing the low voltage component generated by the correction control unit 43, and the effective current instantaneous command value, which is the d axis current reference value for removing the power factor and harmonic components, and the q axis current reference. The reactive current instantaneous command value, which is a value, is provided to the instantaneous error current generation unit 44 through step 119.

In addition, the error instantaneous current generation unit 44 is the d-axis instantaneous current detection value and q-axis instantaneous current detection value supplied from the current monitoring unit 42 and the d-axis current reference value supplied from the correction control unit 43 And generating an error of the q-axis current reference value to generate a d-axis error instantaneous current value and a q-axis error instantaneous current value.

The d-axis error instantaneous current value and the q-axis error instantaneous current value are provided to the instantaneous voltage reference value generator 45.

The instantaneous voltage reference value generating unit 45 generates a d-axis instantaneous voltage reference value and a q-axis instantaneous voltage reference value based on a preset proportional integral expression of the d-axis error instantaneous current value and the q-axis error instantaneous current value, The generated d-axis instantaneous voltage reference value and the q-axis instantaneous voltage reference value are provided to the conversion unit 46.

The conversion unit 46 converts the d-axis instantaneous voltage reference value and the q-axis instantaneous voltage reference value of the synchronous coordinate system into the stationary coordinate system, and then converts the converted α-axis instantaneous voltage reference value into the β-axis instantaneous voltage reference value, The β-axis instantaneous voltage reference value of the converted stationary coordinate system is provided to the PWM correction generator 47.

The PWM correction generator 47 generates a correction value for the PWM signal for each phase based on the received β-axis instantaneous voltage reference value, and supplies the generated PWM correction signal to the PWM control unit 37.

The PWM signal of the PWM control unit 37 is corrected according to the PWM correction signal and then controls the operation of the converter 35 through the corrected PWM signal.

Accordingly, high-quality AC power is transmitted to the grid side 10 and the load side 50 by controlling the power factor, harmonics, and low voltage components generated on the grid side 10 based on the PWM correction signal.

On the other hand, the correction control unit 43 determines whether the power failure based on the AC power supplied from the system side 10, and when the determination is determined to be a power failure switching signal for switching the switch unit 70 to the off state (SW1) is generated, and the generated switching signal SW is supplied to the switch unit 70.

Then, the switch unit 70 is switched to the off state to cut off the connection between the grid side 10 and the load side 50, and transfers the discharge power of the converter unit 35 to the load side 50.

That is, in the normal state in which the power failure does not occur, the switch unit 70 is switched on so that the power of the grid side 10 is rectified through the bidirectional converter device 30, and is also provided to the load side 50. When the power failure, the switch unit 70 is switched off within 150 msec to cut off the connection between the grid side 10 and the load side 50 to convert the discharge power of the electrical storage unit 33 charged with the grid side 10 power. Supply to the load side 50 via 35

According to an embodiment of the present invention, the PWM of the bi-directional converter device based on the power factor correction command, harmonic correction command, and instantaneous power factor control supplied from the current and voltage and the active power supplied to the grid side in the PWM converting bidirectional converter device By correcting the signal, the power factor, low voltage, and harmonics included in the active power of the grid side 10 can be improved to maximize energy efficiency, and the grid side 10 and the load side 50 are connected in the event of power failure. By adding a separate switch unit 70 for transmitting the discharge power of the bidirectional converter device 30 to the load side by blocking the power supply, it protects the grid side and the load side in a simple and efficient manner in a simple configuration and improves efficiency, reliability and stability. You can do it.

Although the present invention has been described in detail with reference to preferred embodiments, the present invention is not limited to the above-described embodiments, and the technical field to which the present invention belongs without departing from the gist of the present invention as claimed in the following claims. Anyone skilled in the art will have the technical idea of the present invention to the extent that various modifications or changes are possible.

In the PWM converting bidirectional converter device, the system side (by correcting the PWM signal of the bidirectional converter device based on the power factor correction command, the harmonic correction command, and the instantaneous power factor control supplied from the active power and the current and voltage supplied to the grid side) 10) Energy efficiency can be improved to the maximum by improving power factor, low voltage, and harmonics, and in case of power failure, the connection between the grid side 10 and the load side 50 is cut off to transfer the discharge power of the bidirectional converter device to the load side. By adding the switch unit 70 separately, the accuracy and reliability aspects of the operation for the ESS device that can protect the grid side and the load side in case of power failure and improve the efficiency, reliability, and stability with a simple configuration and further performance It can make a big step forward in efficiency, and there is a good possibility of commercialization or sales of the applied ESS device. Since not only the degree to apparently conducted in reality the invention there is industrial applicability.

Claims (11)

delete In an ESS device having an uninterrupted function of charging and discharging grid-side power by a bidirectional converter device based on a PWM signal, and transferring the power to a load side in the event of power failure,
The bidirectional converter device,
A converter that receives the grid-side power and converts it into DC power and outputs the converted DC power into AC power and transfers it to the load side and the grid side, a power storage unit storing the DC power of the converter, and stored in the power storage unit. PWM control unit for generating and supplying a PWM signal for controlling the operation of the converter according to the determined synchronous phase angle, and the power factor correction supplied from the grid-side power and the grid-side effective power output from the bidirectional converter device A control unit for correcting the PWM signal based on a command, a harmonic correction command, and an instantaneous unit power factor control command,
The control unit,
A phase lock loop (PLL) unit for receiving a voltage on one of the grid-side AC powers to derive a synchronous phase angle;
A current monitoring unit configured to monitor a current pattern of the grid-side power based on the synchronous phase angle of the PLL unit to generate a d-axis instantaneous current detection value and a q-axis instantaneous current detection value of the synchronous coordinate system, respectively;
Active current that is the d-axis current reference value of the synchronous coordinate system to remove distortion of power factor, harmonics, or low voltage based on power factor correction command, harmonic correction command, and instantaneous power factor control command supplied from externally supplied active power A correction control unit for generating an instantaneous current command value and an reactive current instantaneous command value, which are q reference current values, respectively;
The error instantaneous of the d-axis is calculated by calculating an error for each of the d-axis current reference value and the q-axis current reference value or the q-axis current reference value of the correction controller and the d-axis instantaneous current detection value and the q-axis instantaneous current detection value of the current monitoring unit. An error instantaneous current generation unit for generating a current value and an error instantaneous current value of the q-axis, respectively;
An instantaneous voltage reference value generation unit for deriving an instantaneous voltage reference value of the d-axis and an instantaneous voltage reference value of the q-axis based on a proportional integral expression formula for the error instantaneous current value of the d-axis and the error instantaneous current value of the q-axis, respectively; ,
The instantaneous error voltage reference value of the d-axis and the instantaneous error voltage reference value of the q-axis are converted into the α-axis instantaneous voltage reference value and the β-axis instantaneous voltage reference value of the stationary coordinate system based on the synchronization phase angle. A conversion unit for matching the α-axis instantaneous voltage reference value with the β-axis instantaneous voltage reference value,
And a PWM correction generator for deriving a PWM correction signal for each phase based on the α-axis instantaneous voltage reference value and the β-axis instantaneous voltage reference value of the conversion unit, and correcting the PWM signal of the PWM control unit with the derived PWM correction signal. An ESS device having a power failure function, characterized in that. The method of claim 2, wherein the correction control unit,
Based on the AC power of the grid for each phase, a low voltage correction algorithm that determines whether a segment has been generated and generates a reactive current instantaneous command value, which is a q-axis current reference value, to remove distortion of low voltage components when the segment is generated, A voltage compensation module,
A power factor correction module for receiving a power factor correction command and an instantaneous unit power factor control command supplied from the active power of the grid side and executing a power factor correction algorithm for correcting the power factor component included in the grid side power;
Harmonic correction that executes a harmonic correction algorithm that corrects harmonic components for grid power by controlling the harmonic components (harmonics) for multiple orders included in the grid current based on harmonic correction commands supplied from grid power. ESS device having a power failure function comprising a module. The method of claim 3, wherein the correction control unit,
From the voltage of each phase supplied to the grid side power, it is determined whether a segment of grid side power has occurred,
And an EG device having a power failure function for generating a reactive current instantaneous command value, which is a q-axis current reference value, by performing low voltage correction through a low voltage correction algorithm when a segment is generated as a result of the determination. The method of claim 4, wherein the correction control unit,
In the case where no segment is generated as a result of the determination, it is determined whether the battery unit is in the charge / discharge mode. When the determination result, the power factor correction command and the instantaneous unit power factor control command generated from the grid-side active power supplied from the outside by executing the power factor correction algorithm ESS device having a power failure function, characterized in that it is configured to generate an active current instantaneous command value that is a d-axis current reference value and an reactive current instantaneous command value that is a q-axis current reference value. The method of claim 5, wherein the correction control unit,
As a result of the determination, when it is not being charged and discharged, the instantaneous current instantaneous value and the instantaneous current instantaneous value, which are the d-axis current reference value and the q-axis current reference value, are used to detect harmonic components included in the grid-side current supplied from the outside to remove the detected harmonics. ESS device having a power failure function, characterized in that it is provided to generate a value. The method of claim 3, wherein the correction control unit,
ESS device having a power failure function characterized in that it is determined based on the AC power supplied from the grid side to generate a switching signal to cut off the connection of the load and the grid side in the event of a power failure. The method according to claim 7, wherein the electrostatic power supply device,
And a switch unit configured to be switched to an off state in the event of a power failure according to a switching signal of the correction controller, to cut off the connection between the grid side and the load side, and to supply the discharge power of the bidirectional converter device to the load side. ESS device having a. delete Receiving the grid-side power from the correction control unit and determining whether a segment for the voltage of each phase of the received grid-side power has occurred;
When the segment is generated, performing a low voltage correction algorithm to generate a reactive current instantaneous command value, which is a q-axis current reference value, and correcting a PWM signal for controlling driving of a bidirectional converter device that delivers the instantaneous current instantaneous command value to grid-side power. Wow,
If the segment does not occur, it is determined whether the battery is being charged or discharged, and when it is being charged, the power factor correction algorithm is executed to generate an active current instantaneous command value, which is the d-axis current reference value, and an reactive current instantaneous command value, which is the q-axis current reference value. And correcting the PWM signal based on the received active current instantaneous command value and the reactive current instantaneous command value. The method according to claim 10, wherein the method,
If it is determined that it is not during the charging and discharging, a harmonic correction algorithm is executed based on the received current of the grid-side power to generate an active current instantaneous command value, which is the d-axis current reference value, and an reactive current instantaneous command value, which is the q-axis current reference value. And correcting the PWM signal based on the instantaneous command value and the reactive current instantaneous command value.

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