KR102112077B1 - Uninterruptible power supply with single winding of output winding and inverter winding - Google Patents

Abstract

The present invention relates to an uninterruptible power supply with a single coil having an output coil and inverter coil formed therein and, more specifically, to an uninterruptible power supply in which the output coil and the inverter coil are formed in a single coil to miniaturize a product, facilitate manufacturing, reduce manufacturing costs, and increase efficiency due to reduction of ohmic loss (loss generated by resistance of a coil). In particular, according to the present invention, one capacitor is used in common to be operated in a normal time as an oscillation capacitor for constantly controlling an output voltage for system power and to be operated in a power failure as an LC sine filter capacitor converting a pulse wave modulation (PWM) output of an inverter into a sine wave. Moreover, through current limit control of a dual loop structure, a power switch element (IGBT, MOSFET, and the like), which is an internal component of the inverter, can be protected and be reliable for a power supply and a system. Accordingly, reliability and competitiveness can be increased in a power supply field and a constant voltage transformer-embedded uninterruptible power supply field, in particular, a steel oscillation transformer-used uninterruptible power supply field and fields similar or related to the same.

Description

Uninterruptible power supply with single winding of output winding and inverter winding

The present invention relates to an uninterruptible power supply device comprising an output winding and an inverter winding in a single winding, and more specifically, by configuring the output winding and the inverter winding in a single winding, miniaturizing the product, improving manufacturing ease, reducing manufacturing cost, and loss ( This is to improve the efficiency by reducing the loss caused by winding resistance.

In particular, the present invention uses one capacitor in common, to operate as a resonant capacitor that constantly controls the output voltage to the grid power, and converts the PWM output of the inverter to a sine wave during a power failure (LC sign filter (LC Sine Filter) relates to an uninterruptible power supply that consists of an output winding and an inverter winding that can be operated as a capacitor.

The constant voltage transformer (CVT), well known as an iron resonant voltage stabilizer (transformer), maintains a constant level of AC output voltage even when the input voltage changes, and has advantages such as fast response characteristics and the ability to withstand overvoltage. This has been widely used.

In the power supply device using the iron resonance transformer, which is a constant voltage output transformer, mainly the utility winding and the inverter winding are located on the primary side of the transformer, the output winding is located on the secondary side, and the two windings on the primary side. A magnetic shunt is positioned between the windings of the secondary and secondary sides to form a large leakage magnetic circuit.

Such a conventional power supply device can obtain a constant output voltage, but has a drawback of low input / output efficiency due to a large leakage inductance circuit. When a power outage occurs in the grid power supply, switching of power between the utility winding and the inverter winding In this process, there is a problem in that the power supply is temporarily stopped and iron resonance for the output winding is lost.

In addition, the power supply device has a difficulty in designing a transformer so that resonance can be maintained even with an inverter winding along with a utility winding with respect to the output winding.

Republic of Korea Registered Utility Model Publication No. 013438 '3 lottery transformer for uninterruptible power supply with inductor'

In order to solve the above problems, the present invention comprises an output winding and an inverter winding in a single winding, thereby miniaturizing the product, improving manufacturing ease, reducing manufacturing cost, and reducing efficiency (loss caused by winding resistance). An object of the present invention is to provide an uninterruptible power supply comprising a single winding of an output winding and an inverter winding that can improve the power.

In particular, the present invention uses one capacitor in common, to operate as a resonant capacitor that constantly controls the output voltage to the grid power, and converts the PWM output of the inverter to a sine wave during a power failure (LC sign filter (LC It is an object to provide an uninterruptible power supply comprising a single winding of an output winding and an inverter winding that can be operated as a capacitor for a sine filter).

In addition, the present invention can protect the power switch elements (IGBT, MOSFET, etc.) that are the internal components of the inverter through the current limit control of the double loop structure, and output winding to improve the reliability of the power supply and system. An object of the present invention is to provide an uninterruptible power supply comprising a single winding and an inverter winding.

In order to achieve the above object, the uninterruptible power supply device consisting of the output winding and the inverter winding according to the present invention in a single winding is configured on the primary side, the utility winding to which the grid power is connected, and the secondary is configured to have a capacitor for resonance. An iron resonant transformer comprising a resonant winding being connected, an output winding consisting of the resonant winding and a single winding, and connected to a load side terminal; And an inverter winding composed of the output winding and a single winding, and when the grid power is normally supplied, operates in a charging mode for charging the battery with grid power. When a power outage occurs in the grid power, the battery power is supplied to the load side terminal. It includes; an inverter that operates in a discharge mode.

In addition, the primary side switch for connecting or disconnecting the utility power and the grid power; A secondary side relay selectively connecting the resonance capacitor to any one of the resonance winding and the load side terminal; And a control unit controlling operations of the primary switch and the secondary relay based on whether the system power is normally supplied.

In addition, when the grid power is normally supplied, the control unit turns on the primary side switch to connect the grid power and the utility winding, and switches the secondary side relay so that the resonance capacitor and the resonance winding are connected. Thus, while supplying the grid power to the load, the inverter operates in a charging mode to control the charging of the battery, and when a power outage occurs in the grid power, the primary side switch is turned off to turn off the grid power and utilities. The winding may be disconnected, and the secondary side relay may be switched so that the resonance capacitor and the load side terminal are connected, so that the inverter operates in a discharge mode to control the supply of battery power to the load.

Further, in the discharge mode, a control unit that checks the output voltage of the load-side terminal and generates a PWM signal based on the output voltage; further includes, and the inverter is controlled by operation by the PWM signal generated by the control unit , A sine wave power may be supplied to the load terminal.

In addition, the control unit may control the operation of the inverter according to the monitoring result of the load-side terminal by using a coordinate transformation by d-q transformation that converts the amount of change over time to a fixed value.

In addition, the coordinate transformation may be performed by at least one of the sensing value of the load-side terminal and the output value of the inverter, and a phase shift value obtained by phase shifting the coordinate shift value by d-q conversion.

In addition, the control unit, a current controller using a coordinate conversion of the d-q conversion method; And a voltage controller using a coordinate transformation of the d-q conversion method. The operation of the inverter can be controlled by a dual loop controller structure.

In addition, the controller may further include a limiter configured to perform current limit control on the output current in accordance with voltage limit control on the output voltage of the inverter in the discharge mode.

In addition, the control unit performs limit control on the output voltage of the load side terminal by the voltage controller to prevent overvoltage on the load, and performs limit control on the operating current inside the inverter by the current controller to perform internal control of the inverter. Devices can be protected.

In addition, the inverter converts the pulse-width modulated output of the inverter into a sinusoidal wave by converting the resonant capacitor to a sine filter capacitor in a discharge mode and supplies it to a load side terminal.

By the above-described solution, the present invention comprises an output winding and an inverter winding in a single winding, thereby miniaturizing the product, improving manufacturing ease, reducing manufacturing cost, and reducing efficiency (loss caused by winding resistance). There is an advantage that can be improved.

Through this single winding structure, the present invention does not require a design to maintain the resonant state of the inverter winding and the output winding, and has the advantage of directly controlling the power supplied to the load by controlling the operation of the inverter.

In particular, the present invention uses one capacitor in common, to operate as a resonant capacitor that constantly controls the output voltage to the grid power, and converts the PWM output of the inverter to a sine wave during a power failure (LC sign filter (LC Sine Filter) has the advantage of being able to operate as a capacitor.

In addition, the present invention has the advantage of being able to protect the power switch elements (IGBT, MOSFET, etc.), which are the internal components of the inverter, through the double-loop structure current limit control, and to improve the reliability of the power supply and system. have.

Therefore, it is possible to improve reliability and competitiveness in the field of the power supply unit and the field of the uninterruptible power supply composed of a constant voltage transformer, in particular, the field of the uninterruptible power supply using an iron resonance transformer, as well as similar or related fields.

1 is a circuit diagram showing an embodiment of an uninterruptible power supply device comprising a single winding of an output winding and an inverter winding according to the present invention.
FIG. 2 is a block diagram showing a specific embodiment of the control unit shown in FIG. 1.
3 is a circuit diagram illustrating a specific embodiment of the primary side shown in FIG. 1.
4 is a circuit diagram illustrating a specific embodiment of the secondary side shown in FIG. 1.
FIG. 5 is a flowchart illustrating the operation of FIG. 1.
6 and 7 are views for explaining coordinate transformations processed by the control unit shown in FIG. 1.

The example of the uninterruptible power supply device comprising the output winding and the inverter winding according to the present invention in a single winding can be variously applied, and the most preferred embodiment will be described below with reference to the accompanying drawings.

1 is a circuit diagram showing an embodiment of an uninterruptible power supply device comprising a single winding of an output winding and an inverter winding according to the present invention.

Referring to FIG. 1, an uninterruptible power supply device comprising an output winding and an inverter winding in a single winding includes an iron resonance transformer 100 and an inverter 200.

The iron resonance transformer 100 is configured on the primary side, the utility winding 111 to which the grid power 10 is connected, and the resonance winding 123 to which the resonant capacitor 130 is connected to the resonance winding 123 and the resonance winding ( 123) and includes an output winding 121 to which the load side terminal is connected, and an inverter winding 122 to the output winding 121 is configured as a single winding. Here, the resonance capacitor 130 may be used to obtain a constant voltage characteristic due to resonance phenomenon.

As a result, on the secondary side of the iron resonance transformer 100, the output winding 121 and the inverter winding 122 are composed of a single winding on the resonance winding 123.

The inverter 200 is connected to the inverter winding 122 composed of the output winding 121 and the single winding, and operates in a charging mode for charging the battery with the grid power 10 when the grid power 10 is normally supplied. , If an abnormality such as a power outage occurs in the grid power supply 10, it may operate in a discharge mode in which the power of the battery is supplied to the load side terminal 20.

Thus, the uninterruptible power supply of the present invention may further include a primary side switch 140, a secondary side relay 150, and a control unit 300 for controlling them.

The primary switch 140 is configured between the grid power supply 10 and the utility winding 111, and can perform a function of connecting or disconnecting the electrical connection relationship between the grid power supply 10 and the utility winding 111. have.

The secondary relay 150 is connected to the resonant capacitor 130, the resonant winding 123, and the load side terminal 20, respectively, so that the resonant capacitor 130 is resonant winding 123 and the load side terminal 20. It can perform the function of selectively connecting with one.

The control unit 300 controls the operation of the primary side switch 140 and the secondary side relay 150 based on whether the system power source 10 is normal, and the primary side switch 140 and the secondary side relay 150 Depending on the operation of the inverter 200 may operate in a charge mode or a discharge mode.

For example, when the grid power supply 10 is normally supplied, the controller 300 connects the grid power supply 10 and the utility winding 111 by turning on the primary side switch 140, and simultaneously resonates. By switching the secondary relay 150 so that the capacitor 130 and the resonant winding 123 are connected, the inverter 200 operates in a charging mode while supplying the grid power 10 to the load to control the charging of the battery. Can be.

As another example, the controller 300 may turn off the primary side switch 140 when the system power supply 10 is cut off due to a power failure or a normal power supply due to various factors causes the system power supply 10 to be turned off. ) And the utility winding 111 is cut off, and the secondary relay 150 is switched so that the resonant capacitor 130 and the load side terminal 20 are connected, so that the inverter 200 operates in the discharge mode to operate the battery. It can be controlled to supply power to the load.

Hereinafter, the circuit configuration of the control unit 300 and the primary and secondary sides will be described in more detail.

FIG. 2 is a block diagram showing a specific embodiment of the control unit shown in FIG. 1, FIG. 3 is a circuit diagram showing a specific embodiment of the primary side shown in FIG. 1, and FIG. 4 is a specific one of the secondary side shown in FIG. It is a circuit diagram showing an embodiment, and FIG. 5 is a flowchart for explaining the operation of FIG. 1.

Referring to FIG. 2, the control unit 300 includes a control unit 310, an electrostatic detector 320, an output voltage detector 330, a battery state detector 340, a switch control signal generator 350, and a relay control signal generator ( 360) and an inverter control signal generator 370.

Referring to FIG. 3, the electrostatic detector 320 includes an input voltage detection module 321 and an input current detection module 322 to check the state of the grid power supply 10, and switches the control unit 310 The control signal generator 350 may include an SCR Gate Pulse Generator 351.

4, the output voltage detector 330 includes an output voltage detection module 331, a load current detection module 332 and an inverter current detection module 333 to check the output of the load side terminal 20 In addition, the inverter control signal generator 370 of the control unit 310 may be configured to include a PWM Signal Generator 371.

In addition, the battery state detector 340 may include a battery voltage detection module 341 and a battery current detection module 342 as shown in FIG. 4.

In FIG. 3, the reference numeral '141' is a SCR (Silicon Controlled Rectifier), which is a high voltage large current switching device, also called a thyristor.

Each configuration will be described with reference to FIG. 5 as follows.

First, the system is driven, an initial environment is set, and a phase locked loop (PLL) is synchronized with the input voltage checked by the input voltage detection module 321 to extract the phase of the input voltage (S111).

Thereafter, the control unit 310 monitors whether the grid power supply 10 is normally supplied through at least one of the input voltage detection module 321 and the input current detection module 322 (S112).

At this time, if an abnormality such as a power failure occurs in the grid power supply 10, the control unit 310 turns off the SCR 141 through the SCR Gate Pulse Generator 351, and the relay control signal generator ( After connecting the secondary relay 150 to the load side terminal 20 that is the output side through 360 (S113), the inverter 200 is operated in a discharge mode (S114).

At this time, the control unit 310 sends a sine wave reference signal to the PWM signal generator 371 to generate the output voltage, and the pulse width modulated output voltage obtained by the switching operation of the inverter 200 is its own inductance component of the transformer winding It is converted to a sine wave by the filtering action of the over-resonant capacitor 130 and supplied to the load-side terminal 20.

In other words, the control unit 300 checks the output voltage of the load-side terminal in the discharge mode, generates a PWM signal according to the output voltage, and the inverter 200 controls operation by the PWM signal generated by the control unit 300 The sine wave power is supplied to the load terminal.

Thereafter, when the grid power 10 is restored to a normal state (S115), after synchronizing the output voltage of the inverter 200 to the input voltage (S116), the SCR 141 is turned on and the secondary relay ( 150) is connected to the resonant capacitor 130 by the resonant winding 123 by controlling (S117), and the inverter 200 is operated in a charging mode to charge the battery (S118).

Also, the control unit 310 may control the charging and discharging of the battery while monitoring the state of the battery through the battery voltage detection module 341 and the battery current detection module 342.

On the other hand, since the signal converted by the iron resonance transformer 100 is a value that fluctuates with time, difficulty in controlling it may occur.

Accordingly, in the present invention, it is possible to enable easier and more precise control by converting and dealing with a value (variation) that changes over time to a fixed value, which will be described in more detail below.

6 and 7 are views for explaining coordinate transformations processed by the control unit shown in FIG. 1.

Referring to FIG. 6, the control unit 300 controls the operation of the inverter 200 according to the monitoring result of the grid power supply 10 using coordinate conversion by dq conversion that converts the amount of change over time to a fixed value. Can be.

At this time, the coordinate transformation is the output voltage (Vo) detected by the output voltage detection module 331 among the sensing values of the load-side terminal as shown in FIG. 7 and the inverter current (iinv) detected by the inverter current detection module 333 And, it may be performed by the coordinate conversion values (Vd, Vq, id, iq) calculated by dq conversion of the phase shift value of the phase shift of the output voltage (Vo) and the inverter current (iinv).

In addition, the controller 300 controls the operation of the inverter 200 by a dual loop controller structure including a current controller and a voltage controller using a d-q conversion method coordinate conversion.

In addition, the controller 300 may further include a limiter that performs voltage limit control and current limit control on the output voltage and output current of the inverter 200 in the discharge mode.

For example, as shown in FIG. 6, the control unit 300 performs voltage limit control by a voltage controller using a dq conversion method coordinate conversion, and a limiter according to the result of the voltage limit control. The current limit control can be performed by interworking with a current controller that uses a dq conversion method coordinate conversion, thereby protecting elements inside the inverter 200.

In the above, the uninterruptible power supply device comprising the output winding and the inverter winding according to the present invention in a single winding has been described. It will be understood that such a technical configuration of the present invention can be implemented in other specific forms by those skilled in the art to which the present invention pertains without changing the technical spirit or essential features of the present invention.

Therefore, the above-described embodiments are to be understood in all respects as illustrative and not restrictive.

100: iron resonance transformer
111: Utility winding 121: Output winding
122: Inverter winding 123: Resonant winding
130: resonant capacitor 140: primary side switch
141: Thyristor (SCR) 150: Secondary relay
200: inverter
300: control unit
310: control unit 320: electrostatic detector
321: input voltage detection module 322: input current detection module
330: output voltage detector 331: output voltage detection module
332: load current detection module 333: inverter current detection module
340: battery status detector 341: battery voltage detection module
342: battery current detection module 350: switching control signal generator
351: SCR Gate Pulse Generator 360: Relay Control Signal Generator
370: Inverter control signal generator 371: PWM Signal Generator

Claims (10)

An iron resonant transformer comprising a utility winding configured on the primary side to connect a grid power source, a resonance winding configured on the secondary side to connect a resonant capacitor, and an output winding configured to consist of the resonance winding and a single winding to which a load side terminal is connected; And
It is connected to the inverter winding composed of the output winding and the single winding, and when the grid power is normally supplied, it operates in a charging mode that charges the battery with grid power, and when a power outage occurs in the grid power, the battery power is supplied to the load side terminal. Including an inverter operating in a discharge mode;
A primary side switch connecting or disconnecting the grid power and the utility winding;
A secondary side relay selectively connecting the resonance capacitor to any one of the resonance winding and the load side terminal; And
An uninterruptible power supply device comprising an output winding and an inverter winding in a single winding, further comprising a control unit that controls the operation of the primary switch and the secondary relay based on whether the system power is normally supplied. According to claim 1,
The control unit,
When the grid power is normally supplied, the primary side switch is turned on to connect the grid power and the utility winding, and the relay is switched so that the resonance capacitor and the resonance winding are connected, so that the grid power is supplied. While supplying to the load, the inverter operates in a charging mode to control to charge the battery,
When a power failure occurs in the grid power, the primary side switch is turned off to cut off the connection of the grid power and the utility winding, and the secondary side relay is switched to connect the resonance capacitor and the load side terminal, An uninterruptible power supply comprising an output winding and an inverter winding in a single winding, characterized in that the inverter operates in a discharge mode to control the supply of battery power to a load. According to claim 1,
The inverter,
An uninterruptible power supply comprising an output winding and an inverter winding in a single winding, by converting the pulse width modulated output of the inverter to a sine wave by converting the resonance capacitor to a sine filter capacitor in the discharge mode. According to claim 1,
Further comprising a control unit for checking the output voltage of the load terminal in the discharge mode, and generating a PWM signal based on the output voltage;
The inverter,
An uninterruptible power supply comprising a single winding of an output winding and an inverter winding, characterized in that operation is controlled by a PWM signal generated by the control unit to supply power of a sine wave to the load side terminal.
The method of claim 4,
The control unit,
An uninterruptible power supply consisting of a single winding of an output winding and an inverter winding, characterized in that the operation of the inverter is controlled according to the monitoring result of the load-side terminal by using a coordinate transformation by dq conversion that converts a change in time to a fixed value. Device.
The method of claim 5,
The coordinate transformation,
An uninterruptible power supply consisting of a single winding of an output winding and an inverter winding, characterized in that it is performed by at least one of the sensing value of the load terminal and the output value of the inverter, and a coordinate conversion value calculated by dq-converting the phase shift value of the phase shift. Device.
The method of claim 5,
The control unit,
a current controller using a coordinate conversion of the dq conversion method; And
An uninterruptible power supply device comprising a single winding of an output winding and an inverter winding characterized in that the operation of the inverter is controlled by a dual loop controller structure including a voltage controller using a dq conversion method coordinate conversion.
An iron resonant transformer comprising a utility winding configured on the primary side to connect a grid power source, a resonance winding configured on the secondary side to connect a resonant capacitor, and an output winding configured to consist of the resonance winding and a single winding to which a load side terminal is connected; And
It is connected to the inverter winding composed of the output winding and the single winding, and when the grid power is normally supplied, it operates in a charging mode that charges the battery with grid power, and when a power outage occurs in the grid power, the battery power is supplied to the load side terminal. Including an inverter operating in a discharge mode;
Further comprising a control unit for checking the output voltage of the load terminal in the discharge mode, and generating a PWM signal based on the output voltage;
The inverter,
The operation is controlled by the PWM signal generated by the control unit, and supplies sine wave power to the load terminal,
The control unit,
Controlling the operation of the inverter according to the monitoring result of the load side terminal by using a coordinate transformation by dq transformation that converts the amount of change over time to a fixed value,
a current controller using a coordinate conversion of the dq conversion method; And
Voltage controller using a coordinate conversion of the dq conversion method; By controlling the operation of the inverter by a dual loop controller structure comprising,
In accordance with the voltage limit control for the output voltage of the inverter in the discharge mode, the limiter for performing current limit control for the output current; The uninterruptible power supply device comprising an output winding and an inverter winding in a single winding. The method of claim 8,
The coordinate transformation,
An uninterruptible power supply consisting of a single winding of an output winding and an inverter winding, characterized in that it is performed by at least one of the sensing value of the load terminal and the output value of the inverter, and a coordinate conversion value calculated by dq-converting the phase shift value of the phase shift. Device. The method of claim 8,
The control unit,
Limit control of the output voltage of the load side terminal is performed by the voltage controller to prevent overvoltage to the load,
An uninterruptible power supply comprising an output winding and an inverter winding in a single winding, characterized in that the current controller controls the operating current inside the inverter to protect the elements inside the inverter.

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