KR102315046B1 - Apparatus of Zero­voltage Discharge - Google Patents

Abstract

The present invention relates to a device for discharging a zero voltage. The device for discharging the zero voltage in the present invention comprises: an operating voltage applying means that generates and applies a first operating voltage and a second operating voltage; a first link capacitor connected to an output-side node of the operating voltage applying means, and connected between a first node and a second node so that the first operating voltage is applied; and a second link capacitor connected to the output-side node of the operating voltage applying means, and connected between the second node and a third node so that the second operating voltage is applied. Therefore, the present invention is capable of reducing an internal pressure of a switch.

Description

Apparatus of Zerovoltage Discharge

The present invention relates to a zero-voltage discharging device, and in particular, by configuring the battery to be charged and discharged while maintaining a continuous turned-on state without repeatedly turning on and off related switching elements in a battery discharging mode, the withstand voltage of the switch is reduced. It is possible to reduce the power loss for charging and discharging by configuring so that a charging current and a discharging current can be generated only by selectively turning on the switching elements while allowing a constant operating voltage to be applied. It relates to a zero-voltage discharge device capable of reducing and simplifying a control operation for charging and discharging.

The definition of zero voltage discharge refers to operating in a constant current mode (CCM) in which the magnitude of current is constant until the battery voltage reaches 0V in the process of discharging the battery.

As the need for zero-voltage discharge, the charger/discharger is used for general charging and discharging (Formation) used in the manufacture of secondary batteries, and for cyclers that repeat charging and discharging for more repetitions for product design and research. In the case of equipment for cyclers, the voltage range is 0 ~ 4.5V, and since it must be discharged by dropping to a lower voltage, it is important to implement a zero voltage discharge circuit in order to meet the user's requirements.

The reason why zero voltage discharge cannot be implemented in the existing circuit is that the load wiring is long (about 6 to 10m) in the case of a charger/discharger, and a voltage drop occurs when current flows through the load wiring (about 0.7 to 1.0 V), and also inside the circuit. As a voltage drop occurs due to the conduction of a semiconductor device (diode, MOSFET, etc.), the constant current discharge cannot be maintained in a region where the battery voltage is low due to the voltage drop components. For this reason, in the conventional charging/discharging circuit, it was not possible to maintain discharge at a constant current when the battery voltage was 2.0V or less.

In this way, the conventional secondary battery charging/discharging circuit used for testing the secondary battery could only discharge up to a certain voltage of the secondary battery (eg, a voltage of 20% of the rated voltage) and not discharge below that. couldn't Accordingly, there was a problem in that the secondary battery could not be sufficiently tested.

In order to solve this problem of the conventional charging and discharging circuit, Korean Patent Registration No. 10-1197078 (hereinafter referred to as "prior art literature") implements discharging only with a switching operation in a state where a separate auxiliary power source is not added to the secondary Disclosed is a zero-voltage discharge circuit device having an active switching element capable of sufficiently discharging a small amount of voltage (20% or less to 0%) remaining in a battery.

However, in the zero voltage discharge circuit device presented in the prior art document, since the switching on/off operation of the relevant switching elements is repeated according to PWM control during charging or discharging, the withstand voltage of the switching elements due to parasitic resonance is inevitably increased, For this reason, the cost required for circuit construction by using high withstand voltage switching elements is inevitably increased.

In addition, the zero voltage discharge circuit device presented in the prior art document requires selective control of all switching elements connected to the primary and secondary sides of the transformer to generate charging current and discharging current, and during charging and discharging operations There is a problem in that the switching loss increases due to the occurrence of hard switching of the primary side switching elements, and it is a selective bidirectional structure that requires operation timing change when changing the charging and discharging directions. .

Republic of Korea Patent Registration No. 10-1197078 (Announcement date: November 07, 2012, title of invention: Zero-voltage discharge circuit device with active switching element)

The present invention has been devised to solve the problems of the prior art as described above, and is configured so that the battery can be charged and discharged while maintaining a continuous turn-on state without repeatedly turning on and off related switching elements in the battery discharge mode. Accordingly, an object of the present invention is to provide a zero voltage discharge device capable of reducing the withstand voltage of a switch and reducing conduction loss.

In addition, the present invention can reduce the power loss for charging and discharging by configuring so that a constant operating voltage can be applied and at the same time generate a charging current and a discharging current only by selectively turning on the switching elements, and It is an object of the present invention to provide a zero-voltage discharge device capable of simplifying a control operation.

Another object of the present invention is to provide a zero-voltage discharge device capable of improving overall operating efficiency and reducing overall cost by simply configuring an overall switch configuration and an output filter configuration.

In addition, the present invention provides a zero-voltage discharging device that prevents a time delay from occurring according to the operation timing change for operation of the switching elements by configuring so that there is no need to change the separate operation timing for operating the switching elements during charging and discharging. for that purpose to provide.

In order to solve the above problems, the constituent means constituting the zero voltage discharge device according to the present invention includes: an operation voltage applying means for generating and applying a first operation voltage and a second operation voltage; a first link capacitor connected to an output node of the operating voltage applying means and connected between a first node and a second node so that the first operating voltage is applied; a second link capacitor connected to an output node of the operating voltage applying means and connected between a second node and a third node so that the second operating voltage is applied; a first charge/discharge switching element having one end connected to the first node and the other end connected to one end of the charge/discharge inductor; a second charge/discharge switching element having one end connected to one end of the charge/discharge inductor and the other end of the first charge/discharge switching element and the other end connected to the third node; a charging/discharging inductor having one end connected to one end of the second charge/discharge switching element and the other end of the first charge/discharge switching element, and the other end connected to a positive (+) terminal of the battery; and a battery connected to a positive (+) terminal at the other end of the charging/discharging inductor and a negative (-) terminal connected to the second node, in the charging mode, only the first charging/discharging switching element is turned on An operation of charging the battery by the first operating voltage is performed, and in a discharging mode, only the second charging/discharging switching element is turned on to discharge the battery by the second operating voltage. do it with

Here, the operating voltage applying means includes a switching unit for switching the direction in which the voltage output from the input power source is applied to the primary winding of the transformer, and is connected to the secondary winding of the transformer so that the first operating voltage and the first operating voltage are applied. 2 It consists of a stabilizing unit for stabilizing and outputting an operating voltage, wherein the secondary winding of the transformer is composed of a first winding and a second winding coupled to each other, the negative electrode of the first winding and the positive electrode of the second winding is connected to the second node, and the switching unit includes a first switching switching element having one end connected to a positive (+) terminal of the input power, one end connected to the other end of the first switching switching element, and the other end connected to the input a second change-over switching element connected to the negative (-) terminal of the power source, one end of the second change-over switching element and the other end of the first change-over switching element are connected to each other and the other end is connected to the positive electrode of the first winding an inductor, a third change-over switching element having one end connected to the cathode of the first winding and the other end connected to the other end of the second change-over switching element; a fourth switching switching element connected to one end of the element, wherein the stabilizing unit includes a first stabilizing switching element having the other end connected to the anode of the first winding and one end connected to the first node, the first stabilizing switching A second stabilizing switching element having one end connected to the other end of the element and the other end connected to the third node, a third stabilizing switching element having one end connected to the cathode of the second winding and the other end connected to the third node, and the It characterized in that it comprises a fourth stabilizing switching element having one end connected to the first node and the other end connected to one end of the third stabilizing switching element.

Here, the voltage applied to the movable means is a current of the switched inductor being controlled to be increased to the maximum current (I + _P) from the minimum current (-I _P) in a first mode, the inductor current of the switching in the second mode the maximum current is controlled to maintain a _(P + I), is controlled to be lowered to a minimum current (-I _P) the inductor current of the switching at the maximum current (I + _P) in a third mode, the fourth In the mode, it is characterized in that the current of the switching inductor is _{controlled to maintain a minimum current (-I P ).}

Here, in the first mode, the first switching switching element and the third switching switching element are controlled to be turned on while the second stabilizing switching element and the fourth stabilizing switching element are conducting, and in the second mode, Controlled so that the first stabilizing switching element and the third stabilizing switching element are turned on in a state in which the first and third switching switching elements are electrically connected, and in the third mode, the first stabilizing switching element and the second stabilizing switching element 3 Controlled so that the second changeover switching element and the fourth changeover switching element are turned on while the stabilization switching element is conducting, and in the fourth mode, the second changeover switching element and the fourth changeover switching element are conducting In the state, the second stabilizing switching element and the fourth stabilizing switching element are controlled to be turned on.

According to the present invention zero voltage discharging device having the above problems and solutions, the battery can be charged and discharged while maintaining a continuous turn-on state without repeatedly turning on and off related switching elements in the battery discharging mode. Therefore, an advantage of reducing the withstand voltage of the switch and reducing the conduction loss is generated.

In addition, according to the present invention, it is possible to reduce power loss for charging and discharging, since it is configured to generate a charging current and a discharging current only by selectively turning on the switching elements while allowing a constant operating voltage to be applied. An effect of making it possible to simplify the control operation for the discharge occurs.

In addition, according to the present invention, since the overall switch configuration and the output filter configuration are simply configured, the overall operating efficiency can be improved and the overall cost can be reduced.

In addition, according to the present invention, since it is configured so that there is no need for a separate operation timing change for operating the switching elements during charging and discharging, there is an advantage in that a time delay does not occur according to the operation timing change for the operation of the switching elements. occurs

1 is a block diagram of a zero voltage discharge device according to an embodiment of the present invention.
2 is a circuit operation diagram for explaining the operation of a zero voltage discharge device according to an embodiment of the present invention.
3 shows a waveform diagram of a control signal for related switching elements and voltage and current at a related node for explaining the operation of the zero voltage discharge device according to an embodiment of the present invention.
4 is a detailed configuration diagram of a zero voltage discharge device according to an embodiment of the present invention.
5 to 8 are circuit operation diagrams for explaining the operation of the operating voltage applying means constituting the zero voltage discharge device according to the embodiment of the present invention.
FIG. 9 shows waveform diagrams of voltages and currents at related nodes and control signals for related switching elements for explaining the operation of the operating voltage applying means constituting the zero voltage discharge device according to the embodiment of the present invention.
10 and 11 are waveform diagrams of voltage and current showing simulation results for a zero voltage discharge device according to an embodiment of the present invention.

Hereinafter, a preferred embodiment of a zero voltage discharge device according to the present invention having the above problems, solutions and effects will be described in detail with reference to the accompanying drawings.

Since the present invention can apply various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail. Effects and features of the present invention, and a method of achieving them, will become apparent with reference to the embodiments described below in detail in conjunction with the drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, and when described with reference to the drawings, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted. .

In the following embodiments, terms such as include or have means that the features or components described in the specification are present, and the possibility of adding one or more other features or components is not excluded in advance.

In the drawings, the size of the components may be exaggerated or reduced for convenience of description. For example, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

In cases where certain embodiments may be implemented differently, a specific order of operations may be performed differently from the described order. For example, two operations described in succession may be performed substantially simultaneously, or may be performed in an order opposite to the order described.

1 is a block diagram of a zero voltage discharge device according to an embodiment of the present invention.

As shown in FIG. 1 , the zero voltage discharging device 100 according to the embodiment of the present invention receives the input power Vin and receives two operating voltages Vo1 and Vo2 for charging and discharging the battery Vbatt. operation voltage applying means 10 for generating and applying the ), and a battery (Vbatt) for charging and discharging is connected between the charging/discharging inductor (L1) and the operating voltage applying means (10).

The operation voltage applying means 10 generates and applies the first operation voltage Vo1 and the second operation voltage Vo2. Specifically, the operating voltage applying means 10 generates and outputs the output voltage Vo, but operates so that the first operating voltage Vo1 and the second operating voltage Vo2 are separated and output. The first operating voltage Vo1 and the second operating voltage Vo2 act as input voltages for charging and discharging the battery Vbatt, respectively.

Here, the output voltage Vo is a voltage between both ends of the operating voltage applying means 10 , specifically, between the first node N1 and the third node N3 in FIG. 1 , and the first operating voltage Vo1 . and the second operation voltage Vo2, and the first operation voltage Vo1 and the second operation voltage Vo2 each have a value of Vo/2. That is, the first operation voltage Vo1 and the second operation voltage Vo2 separated and output from the operation voltage applying means 10 have the same voltage level.

A first link capacitor Co1 and a second link capacitor Co2 capable of storing the first operation voltage Vo1 and the second operation voltage Vo2 are respectively connected to the output node of the operation voltage applying means 10 . .

Specifically, the first link capacitor Co1 is connected to an output node of the operating voltage applying means 10 , and a first node N1 and a second node N2 are applied such that the first operating voltage Vo1 is applied. ) are connected between That is, the first link capacitor Co1 may accumulate the first operating voltage Vo1 output from the operating voltage applying means 10 .

The second link capacitor (Co2) is connected to the output node of the operating voltage applying means (10), between the second node (N2) and the third node (N3) so that the second operating voltage (Vo2) is applied. Connected. That is, the second link capacitor Co2 may accumulate the second operation voltage Vo2 output from the operation voltage applying means 10 .

In this way, the first link capacitor Co1 and the second link capacitor Co2 are separated and connected in parallel to each other, and the first and second operation voltage Vo1 and the second output voltage Vo1 are separated from the operation voltage applying means 10 and output. The operating voltage Vo2 can be separated and stored. Through this, the first link capacitor Co1 and the second link capacitor Co2 operate as voltage stabilizing capacitors for stabilizing the waveform of the voltage of the battery in the charging mode and the discharging mode for the battery.

A first charge/discharge switching device CSW1 and a second charge/discharge switching device CSW2 that are turned on or off by a control means (not shown) so that the charging and discharging operations of the battery Vbatt can be performed It is connected to the first link capacitor Co1 and the second link capacitor Co2. Here, the first charge/discharge switching element CSW1 and the second charge/discharge switching element CSW2 are switching elements and correspond to switching elements directly involved in the charging and discharging operations of the battery Vbatt.

One end of the first charge/discharge switching element CSW1 is connected to the first node N1 and the other end is connected to one end of the charge/discharge inductor L1. The first charge/discharge switching device CSW1 is configured of a metal oxide semiconductor field effect transistor (MOSFET). Specifically, the first charge/discharge switching device CSW1 is disposed such that a drain is connected to the first node N1 and a source is connected to the charge/discharge inductor L1 .

A diode is connected to the first charge/discharge switching element CSW1 including the MOSFET. The diode is connected to prevent damage due to a high counter electromotive force applied to the drain side when the first charge/discharge switching element CSW1 including the MOSFET is turned off from the ON state. The diode is arranged such that an anode is connected to the charge/discharge inductor (L1) and a cathode is connected to the first node (N1).

In addition, one end of the second charge/discharge switching element CSW2 is connected to one end of the charge/discharge inductor L1 and the other end of the first charge/discharge switching element CSW1, and the other end is connected to the third node N3. Connected.

The second charge/discharge switching element CSW2 is also configured of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor, Metal Oxide Semiconductor Field Effect Transistor). Specifically, the second charge/discharge switching element CSW2 is disposed such that a drain is connected to the other end of the first charge/discharge switching element CSW1 and a source is connected to the third node N3 .

A diode is also connected to the second charge/discharge switching element CSW2 composed of the MOSFET. The diode is connected to prevent damage due to a high counter electromotive force applied to the drain side at the moment when the second charge/discharge switching element CSW2 composed of the MOSFET is turned off from the ON state. The diode is arranged such that an anode is connected to the third node N3 and a cathode is connected to the other end of the first charge/discharge switching element CSW1.

One end of the charge/discharge inductor L1 is connected between the first charge/discharge switching element CSW1 and the second charge/discharge switching element CSW2. Specifically, the charge/discharge inductor L1 has one end connected to one end of the second charge/discharge switching element CSW2 and the other end of the first charge/discharge switching element CSW1, and the positive (+) of the battery Vbatt. The other end is connected to the terminal.

The charging/discharging inductor L1 is configured as a current stabilizing coil, and operates so that a charging current and a discharging current may flow stably. That is, the charging/discharging inductor L1 is directly involved in allowing the charging current and the discharging current to flow stably in the battery in the charging mode and the discharging mode for charging and discharging the battery Vbatt.

The battery Vbatt is connected to a positive (+) terminal of the other end of the charging/discharging inductor L1 and a negative (-) terminal is connected to the second node N2. The negative (-) terminal of the battery Vbatt is connected between the second node N2 , more specifically, the first link capacitor Co1 and the second link capacitor Co2 .

Hereinafter, the operation of the zero voltage discharge device according to the embodiment of the present invention configured as described above will be described with reference to the circuit diagram of FIG. 2 and the waveform diagram of FIG. 3 .

First, in the charging mode, only the first charging/discharging switching element CSW1 is turned on to charge the battery Vbatt by the first operating voltage Vo1 .

As shown in FIG. 3 , a control unit (not shown) controls so that only the first charge/discharge switching element CSW1 is turned on and the second charge/discharge switching element CSW2 maintains an off state. Then, the inductor current iL as shown in the upper circuit diagram of FIG. 2 flows. Specifically, the inductor current iL is a first link capacitor Co1 -> first charge/discharge switching element CSW1 -> charge/discharge inductor L1 -> battery Vbatt -> first link capacitor Co1 ) flows along a closed loop formed by The battery Vbatt performs a charging operation by the inductor current iL.

In this charging mode, the first charging/discharging switching element CSW1 conducts and the first operating voltage Vo1 is applied to the front end voltage Vx of the charging/discharging inductor L1. Accordingly, as shown in FIG. 3 , the charging/discharging inductor current rises with a slope of (Vo1-Vbatt)/L, and the charging operation of the battery Vbatt is performed through this process.

Next, in the discharging mode, only the second charge/discharge switching element CSW2 is turned on to discharge the battery Vbatt by the second operation voltage Vo2 .

As shown in FIG. 3 , a control unit (not shown) controls so that only the second charge/discharge switching device CSW2 is turned on and the first charge/discharge switching device CSW1 maintains an off state. Then, the inductor current iL as shown in the lower circuit diagram of FIG. 2 flows. Specifically, the inductor current iL is a second link capacitor (Co2) -> battery (Vbatt) -> charge/discharge inductor (L1) -> second charge/discharge switching element (CSW2) -> second link capacitor (Co2) ) flows along a closed loop formed by The battery Vbatt performs a discharging operation by the inductor current iL.

In such a discharging mode, the second charge/discharge switching element CSW2 conducts, so that the voltage Vx at the front end of the charge/discharge inductor L1 is negatively applied to the second operation voltage -Vo2. Accordingly, as shown in FIG. 3 , the charging/discharging inductor current falls with a slope of (-Vo2-Vbatt)/L, and the discharging operation of the battery Vbatt is performed through this process.

In this way, even when the voltage of the battery Vbatt becomes 0, it is possible to secure a falling slope of -Vo2/L, so that it is possible to control the charge/discharge current.

According to the zero voltage discharging device of the present invention having such a configuration and operation, the battery is charged and discharged in a state in which the related switching elements CSW1 and CSW2 are continuously turned on without repeatedly turning on and off in the battery discharging mode. Since it is configured so that it is possible to reduce the breakdown voltage of the switch and the conduction loss can be reduced, there is an advantage.

In addition, according to the present invention, since it is configured to generate a charging current and a discharging current only by selectively turning on the switching elements CSW1 and CSW2 while allowing a constant operating voltage to be applied, power loss for charging and discharging is reduced. can be reduced, and the effect of making it possible to simplify the control operation for charging and discharging occurs.

As described above, the zero voltage discharge device 100 according to the present invention is separated into two link capacitors Co1 and Co2 to operate independently. To this end, the operating voltage applying means 10 receives the input power Vin and generates and outputs two operating voltages Vo1 and Vo2.

To this end, as shown in FIG. 4 , the zero voltage discharging device 100 according to the embodiment of the present invention includes an operating voltage applying unit 10 , and the operating voltage applying unit 10 is an input power supply ( Vin) is connected to a switching unit 1 for switching the direction in which the voltage output from the transformer 3 is applied to the primary winding of the transformer 3, and is connected to the secondary winding of the transformer 3 and the first operating voltage Vo1 ) and a stabilizing unit that stabilizes and outputs the second operating voltage Vo2.

The operation voltage applying means 10 should perform an operation to generate and output two stabilized operation voltages Vo1 and Vo2. For this purpose, the secondary winding of the transformer 3 is connected to two windings, that is, the first It consists of a winding (4) and a second winding (5). The first winding 4 and the second winding 5 are coupled to each other. That is, the negative pole of the first winding 4 and the positive pole of the second winding 5 are connected to the battery Vbatt connected to the second node N2 while being connected to each other.

As such, the secondary winding of the transformer 3 is composed of a first winding 4 and a second winding 5 coupled to each other, and the cathode of the first winding 4 and the second winding 5 are coupled to each other. ) is connected to the second node N2 and the battery Vbatt.

The switching unit 1 is composed of four switching elements SW1 , SW2 , SW3 , SW4 and a switching inductor L2 and is connected to the primary winding of the transformer 3 . The switching unit 1 converts the direction of the primary current flowing in the primary winding of the transformer 3 according to the control of the control means (not shown) for the four switching elements.

As shown in FIG. 4 , the switching unit 1 includes a first switching switching device SW1 having one end connected to a positive (+) terminal of the input power Vin, and the first switching switching device SW1. One end is connected to the other end of the second change-over switching element SW2 and the other end is connected to the negative (-) terminal of the input power (Vin) A switching inductor L2 having one end connected to the other end of the element SW1 and the other end connected to the positive pole of the first winding, one end connected to the negative pole of the first winding and the other end connected to the second switching switching element SW2 a fourth change-over switching element (SW3) connected to the other end of SW4) is included.

The four switching switching elements SW1, SW2, SW3, SW4 are turned on or off according to the control of a control means (not shown), and through this process, the direction of the primary side current of the transformer 3 is switched It corresponds to a switching device that performs

The four switching switching elements SW1, SW2, SW3, and SW4 are composed of a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), and the switching element composed of the MOSFET is turned on in an ON state. A diode is connected to prevent damage due to a high counter electromotive force applied to the drain side at the moment it is turned off.

The current flowing in the secondary winding of the transformer 3 according to the operation of the switching unit 1, specifically, the first winding current is1 flowing in the first winding 4 and the second winding flowing in the second winding 5 The two winding current is2 flows, and through this, the first operating voltage Vo1 and the second operating voltage Vo2 stabilized through the stabilizing unit 7 are generated and output.

The stabilization unit 7 is composed of four switching elements MW1, MW2, MW3, MW4 and is connected to the secondary winding of the transformer 3, and the output side is separated from the two link capacitors Co1 and CO2. has been connected The stabilizing unit 7 is a secondary winding of the transformer 3, specifically, a first winding ( 4) The first starting voltage Vo1 and the second starting voltage stabilized through the process of changing the paths and directions of the first winding current is1 flowing through the second winding 5 and the second winding current is2 flowing through the second winding 5 are changed. A voltage Vo2 is generated and output.

As shown in FIG. 4, the stabilization unit 7 includes a first stabilizing switching element MW1 having the other end connected to the anode of the first winding 4 and one end connected to the first node N1, A second stabilizing switching element MW2 having one end connected to the other end of the first stabilizing switching element MW1 and the other end connected to the third node N3, one end connected to the cathode of the second winding 5 and a third stabilizing switching element MW3 having the other end connected to the third node N3 and one end connected to the first node N1 and the other end connected to one end of the third stabilizing switching element MW3 It is configured to include a fourth stabilizing switching element (MW4).

Since the secondary winding of the transformer 3 is composed of a first winding 4 and a second winding 5, and a first winding current is1 and a second winding current is2 flow for each winding, The first winding current is1 and the second winding current is2 respectively flow along the corresponding closed circuit, and as a result, two operating voltages Vo1 and Vo2 may be generated.

The operating voltage applying means 10 configured as described above has four modes (a first mode (Mode 1), a second mode (Mode 2), and a third mode (Mode)) according to the control of a control means (not shown). 3) and the fourth mode (Mode 4)), and as the four modes are sequentially operated, operating voltages Vo1 and Vo2 separated from each other are output.

As shown in FIG. 9 , the operating voltage applying means 10 has a minimum current ip of the switching inductor L2 in the first mode (Mode 1) under the control of a control means (not shown). It is controlled to increase from (-i _P ) to the maximum current (+i _P ), and in the second mode (Mode 2), the current ip of the switching inductor L2 is maintained at the _{maximum current (+i P )} controlled so that the current (ip) of the switching inductor (L2) in the third mode (Mode 3) is _{controlled to fall from the maximum current (+i P} ) to the minimum current (-i _P ), and the fourth In the mode (Mode 4), the current of the switching inductor L2 is controlled to maintain the _{minimum current (-i P ).}

That is, the operating voltage applying means 10 is controlled so that the current ip of the switching inductor L2 rises from the minimum current to the maximum current in the first mode, and then the maximum current is constant in the second mode. It is controlled to last for a period of time, and then in the third mode, the current ip of the switching inductor L2 is controlled to fall from the maximum current to the minimum current, and finally, in the fourth mode, the minimum current is set for a certain time. Controlled to last for a while.

With the control of the current ip of the switching inductor L2 as described above, the stabilization switching elements MW1, MW2, MW3, and MW4 constituting the stabilization unit 7 are selectively controlled by a control means (not shown). By being controlled to be turned on or off, the operation voltage applying means 10 may generate and output two separated operation voltages Vo1 and Vo2 that are stabilized.

Hereinafter, the operation of the operating voltage applying means 10 constituting the zero voltage discharge device 100 according to the embodiment of the present invention configured as described above will be described with reference to the circuit diagrams of FIGS. 5 to 8 and the waveform diagrams of FIG. 9 . Explain. 5 to 8 are circuit diagrams for explaining the operation of the operating voltage applying means 10 in the first mode, the second mode, the third mode, and the fourth mode, respectively.

In the process described below, it is assumed that the input power Vin is equal to the product of the turns ratio of the transformer and the sum of the operating voltages output from the operating voltage applying means (Vo = Vo1 + Vo2). That is, it is assumed that there is no voltage drop of the switching elements in the turned-on state under an ideal condition, and it is assumed that Vin = nVo and will be described below.

In the first mode (Mode 1), as described above, the current ip of the switching inductor L2 is controlled to increase from the minimum current to the maximum current, and at the same time, the second stabilization switching element MW2 and the fourth stabilization The switching element MW4 is controlled to conduct. That is, as shown in FIG. 5 , in the first mode, the first switching switching element SW1 and The third switching switching element SW3 is controlled to be turned on.

In the first mode, the primary side current ip in the switching unit 1 is the input power Vin -> the first switching switching element SW1 -> the switching inductor L2 -> the primary winding -> the first 3 Change-over switching element (SW3) -> As it flows along the closed circuit formed by the input power (Vin), the current rises from the minimum current to the maximum current.

Looking at the specific operation in the first mode, since the voltage Vi1 at the front end of the switching inductor L2 becomes the input voltage Vin and the voltage Vi2 at the rear end of the switching inductor L2 is maintained at -nVo, the voltage VL of the switching inductor L2 is becomes the quantity. Accordingly, the transformer primary winding current rises. And among the secondary windings, is1 flowing in the first winding 4 flows through the second stabilizing switching element MW2 -> the second link capacitor Co2, and among the secondary windings, flowing in the second winding 5 The current is2 flows through the first link capacitor Co1 -> the fourth stabilizing switching element MW4.

Next, in the second mode (Mode 2), as described above, the current ip of the switching inductor L2 is controlled to maintain the maximum current, and at the same time, the first stabilizing switching element MW1 and the third stabilizing switching element are controlled. (MW3) is controlled to conduct. That is, as shown in FIG. 6 , in the second mode, the first stabilizing switching element MW1 and The third stabilization switching element MW3 is controlled to be turned on.

In the second mode, the primary side current ip in the switching unit 1 is input power Vin -> first switching switching element SW1 -> switching inductor L2 -> primary winding -> first 3 Change-over switching element (SW3) -> flows while maintaining the maximum current along the closed circuit formed by the input power supply (Vin). That is, the primary-side current ip in the second mode flows along the same closed circuit as in the first mode, but is maintained as the maximum current raised in the first mode.

Looking at the specific operation in the second mode, in a state in which the first switching switching element SW1 and the third switching switching element SW3 included in the switching unit 1 connected to the primary side of the transformer are in conduction, the The first stabilizing switching element MW1 and the third stabilizing switching element MW3 included in the stabilizing unit 7 connected to the secondary side of the transformer are turned on. In this second mode, the voltage Vi1 at the front end of the switching inductor L2 becomes the input voltage Vin and the voltage Vi2 at the rear end of the switching inductor L2 becomes +nVo, so that the voltage VL of the switching inductor L2 becomes 0. Therefore, the primary side current ip of the transformer is kept constant. And among the secondary windings, is1 flowing in the first winding 4 flows through the first stabilizing switching element MW1 -> the first link capacitor Co1, and among the secondary windings, flowing in the second winding 5 The current is2 flows through the second link capacitor Co2 -> the third stabilizing switching element MW3.

In the third mode (Mode 1), as described above, the current ip of the switching inductor L2 is controlled to fall from the maximum current to the minimum current, and at the same time, the first stabilization switching element MW1 and the third stabilization The switching element MW4 is controlled so that conduction is maintained. That is, as shown in FIG. 7 , in the third mode, the second switching switching element SW2 and The fourth switching switching element SW4 is controlled to be turned on.

In the third mode, the primary side current ip in the switching unit 1 is the input power Vin -> the fourth switching switching element SW1 -> the primary winding -> the switching inductor L2 -> the second 2 switching switching element (SW2) -> flows along the closed circuit formed by the input power supply (Vin) and falls from the maximum current to the minimum current.

Looking at the specific operation in the third mode, the second switching switching element SW2 included in the switching part in a state in which the first stabilizing switching element MW1 and the third stabilizing switching element MW3 included in the stabilizing part are conducting. ) and the fourth switching switching element SW4 are turned on. In the third mode, the voltage Vi1 at the front end of the switching inductor L2 becomes the input voltage -Vin and the voltage Vi2 at the rear end of the switching inductor L2 is maintained at +nVo, so that the voltage VL of the switching inductor L2 becomes negative. Accordingly, the primary side current of the transformer falls. And among the secondary windings, is1 flowing in the first winding 4 flows through the first link capacitor Co1 -> the first stabilizing switching element MW1, and among the secondary windings, flowing in the second winding 5 The current is2 flows through the third stabilizing switching element MW3 -> the second link capacitor Co2.

Finally, in the fourth mode (Mode 4), as described above, the current ip of the switching inductor L2 is controlled to maintain the minimum current, and at the same time, the second stabilizing switching element MW2 and the fourth stabilizing switching The element MW4 is controlled to conduct. That is, as shown in FIG. 8 , in the fourth mode, the second stabilizing switching element MW2 and The fourth stabilizing switching element MW4 is controlled to be turned on.

In the fourth mode, the primary side current ip in the switching unit 1 is the input power Vin -> the fourth switching switching element SW4 -> the primary winding -> the switching inductor L2 -> the second 2 switching switching element (SW2) -> flows while maintaining the minimum current along the closed circuit formed by the input power supply (Vin). That is, the primary-side current ip in the fourth mode flows along the same closed circuit as in the third mode, but is maintained as the minimum current that has fallen in the third mode.

Looking at the specific operation in the fourth mode, in a state in which the second switching switching element SW2 and the fourth switching switching element SW4 included in the switching unit 1 connected to the primary side of the transformer are in conduction, the The second stabilizing switching element MW2 and the fourth stabilizing switching element MW4 included in the stabilizing unit 7 connected to the secondary side of the transformer are turned on. In the fourth mode, the voltage Vi1 at the front end of the switching inductor L2 becomes the input voltage -Vin and the voltage Vi2 at the rear end of the switching inductor L2 becomes -nVo so that the voltage VL of the switching inductor L2 becomes 0. Therefore, the primary side current of the transformer is kept constant. And among the secondary windings, is1 flowing in the first winding 4 flows through the second link capacitor Co2 -> the second stabilizing switching element MW2, and among the secondary windings, flowing in the second winding 5 The current is2 flows through the fourth stabilizing switching element MW4 -> the first link capacitor Co1.

5 to 9, the input currents io1 and io2 of each of the link capacitors Co1 and Co2 are the input currents of the first link capacitor Co1 and the second link capacitor Co2, respectively, and in an ideal steady state, The average value of io1 is the same as the upper load current ILD1, and the average value of io2 is the same as the lower load current ILD2. Also, io1 is -(iMW1+iMW4) and io2 is -(iMW2+iMW3), so the secondary side switching current has a bias according to the load current deviation. In the extreme, when ILD2 = 0 and a load current occurs only in the upper side, the average current of the lower switching currents iMW2 and iMW3 becomes 0 (that is, the average current of io2 becomes 0), and the second link capacitor Co2 has an average A circulating current of zero is generated and an ideal steady state is maintained in which there is no rise or fall of voltage even at no load.

10 and 11 are waveform diagrams of voltage and current showing simulation results for a zero voltage discharge device according to an embodiment of the present invention.

A simulation experiment was performed to verify the zero voltage discharge device according to the embodiment of the present invention. The simulation specifications were assumed to be Vin=380V, Vo=12V (Vo1=Vo2=6V), iL=+/-150A, and Vbatt variable between 0 and 4V.

As shown in FIGS. 10 and 11 , it can be seen that charging and discharging are well performed in the zero voltage discharging device according to the embodiment of the present invention in the entire battery voltage range, and the first operating voltage Vo1 and the first operating voltage Vo1 2 It can be seen that the operating voltage Vo1 is well maintained at 6V. As a result, by generating and applying two stabilized operating voltages, it is possible to improve the charging and discharging efficiency of the battery.

Although the embodiments according to the present invention have been described above, these are merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent ranges of embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

Vin: input power 1: switching part
SW1: first change-over switching element SW2: second change-over switching element
SW3: third change-over switching element SW4: fourth change-over switching element
L2: switching inductor
3: transformer 4: primary winding
5: Second winding
7: stabilization part MW1: first stabilization switching element
MW2: second stabilizing switching element MW3: third stabilizing switching element
MW4: fourth stabilizing switching element
10: operating voltage application means N1: first node
N2: second node N3: third node
Co1: first link capacitor Co2: second link capacitor
CSW1: first charge-discharge switching element CSW2: second charge-discharge switching element
L1: charge/discharge inductor Vbatt: battery
100: zero voltage discharge device

Claims (4)

actuating voltage applying means for generating and applying the first actuation voltage and the second actuation voltage;
a first link capacitor connected to an output node of the operating voltage applying means and connected between a first node and a second node so that the first operating voltage is applied;
a second link capacitor connected to an output node of the operating voltage applying means and connected between a second node and a third node so that the second operating voltage is applied;
a first charge/discharge switching element having one end connected to the first node and the other end connected to one end of the charge/discharge inductor;
a second charge/discharge switching element having one end connected to one end of the charge/discharge inductor and the other end of the first charge/discharge switching element and the other end connected to the third node;
a charging/discharging inductor having one end connected to one end of the second charge/discharge switching element and the other end of the first charge/discharge switching element, and the other end connected to a positive (+) terminal of the battery;
Doedoe comprising a battery connected to a positive (+) terminal at the other end of the charging/discharging inductor and a negative (-) terminal connected to the second node,
In the charging mode, only the first charging/discharging switching element is turned on to perform an operation in which the battery is charged by the first operating voltage,
In the discharging mode, only the second charging/discharging switching element is turned on, and an operation of discharging the battery by the second operating voltage is performed.
The method according to claim 1,
The operating voltage application means,
A switching unit for switching the direction in which the voltage output from the input power is applied to the primary winding of the transformer, and connected to the secondary winding of the transformer to stabilize the first and second operating voltages and output stabilization made up of wealth,
Here, the secondary winding of the transformer is composed of a first winding and a second winding coupled to each other, the negative pole of the first winding and the positive pole of the second winding are connected to the second node,
The switching unit,
A first change-over switching element having one end connected to the positive (+) terminal of the input power, one end connected to the other end of the first change-over switching element, and the other end connected to the negative (-) terminal of the input power source a switching element, a switching inductor having one end connected to one end of the second switching switching element and the other end of the first switching switching element and the other end connected to the positive electrode of the first winding, and one end connected to the negative electrode of the first winding, a third change-over switching element having the other end connected to the other end of the second change-over switching element, and a fourth change-over switching element having one end connected to the first change-over switching element and the other end connected to one end of the third change-over switching element and
The stabilization unit,
A first stabilizing switching element having the other end connected to the anode of the first winding and having one end connected to the first node, a second end connected to the other end of the first stabilizing switching element and the other end connected to the third node a stabilizing switching element, a third stabilizing switching element having one end connected to the cathode of the second winding and the other end connected to the third node, and one end connected to the first node and the other end connected to one end of the third stabilizing switching element A zero voltage discharge device comprising a fourth stabilizing switching element connected thereto.
3. The method according to claim 2,
The operation voltage application means is that the current in the switched inductor is controlled to be increased to the maximum current (I + _P) from the minimum current (-I _P), the switching current of the inductor in the second mode in the first mode, up to current (I + _P) is controlled to maintain a, in the third mode is controlled to a current of said switching inductor lowered to the maximum current (I + _P) a minimum current (-I _P) in, in the fourth mode, Zero voltage discharge device, characterized in that the current of the switching inductor is _{controlled to maintain a minimum current (-I P ).}
4. The method according to claim 3,
In the first mode, the first switching switching element and the third switching switching element are controlled to be turned on while the second stabilizing switching element and the fourth stabilizing switching element are conducting;
In the second mode, the first stabilizing switching element and the third stabilizing switching element are controlled to be turned on in a state in which the first switching switching element and the third switching switching element are conducting;
In the third mode, the second switching switching element and the fourth switching switching element are controlled to be turned on while the first stabilizing switching element and the third stabilizing switching element are conducting;
In the fourth mode, the second stabilizing switching element and the fourth stabilizing switching element are controlled so that the second and fourth stabilizing switching elements are turned on while the second and fourth switching switching elements are electrically connected.

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