KR200181443Y1 - Charger contained inverting function - Google Patents

Abstract

The present invention relates to an inverter combined charger, the push pull converter 110 capable of DC / DC power conversion in one direction; A forward converter 120 capable of unidirectional DC / DC power conversion; A converter control unit 140 for controlling the push pull converter 110 and the forward converter 120 so as to operate as a single DC / DC converter having bidirectionality to form a stable DC power source; A full bridge inverter 130 capable of bidirectional power transfer; The full bridge inverter 130 is controlled to convert the output of the push pull converter 110 into a stable AC power source, or the full bridge inverter 130 is operated as a bridge rectifier circuit to convert the rectified output into the forward converter ( An inverter controller 150 applied as an input of the 120; And a mode selection switch 160 interlocked to determine the inverter mode and the charger operation mode. When the inverter mode is selected, the DC low voltage of the battery 182 is controlled by the push-pull converter 130 and the converter controller 140. Is converted into a stable DC high voltage, and this DC high voltage is output at a stable AC voltage under the control of the full bridge inverter 130 and the inverter controller 150. When a charger operation mode is selected, an external AC power is supplied to the full AC voltage. The DC voltage is converted into a stable DC voltage by the control of the bridge inverter 130 and the inverter controller 150. The DC voltage forms a stable DC low voltage by the control of the forward converter 120 and the converter controller 140 to form a storage battery ( An inverter combined charger charged in 182 is a technical gist. As a result, one product can be used simultaneously as an inverter and a charger.

Description

Inverter Charger {charger contained inverting function}

The present invention relates to an inverter combined charger, and more particularly, to an inverter combined charger that can be used simultaneously as an inverter and a charger in one product in the use of a mobile power supply.

In general, in the case of the mobile power supply, most of them use the low voltage of the automotive battery to generate the required high voltage AC voltage. The mobile power supply converts the low voltage of the battery into a high DC voltage first, and then converts the high DC voltage into an AC high voltage to generate a desired output. A device for converting a low voltage of the battery, that is, a DC low voltage into a DC high voltage, is called a boost type DC / DC converter. It is called. In addition, a push pull converter is generally applied as the boost type DC / DC converter.

Figure 1 (a) is a view for explaining the configuration of the push pull converter, briefly, two switches (Q1, Q2) are symmetrically connected to the primary side of the transformer, the secondary side of the transformer Is composed of bridge rectifier circuit and LC filter.

In the push pull converter, two switches Q1 and Q2 are alternately turned on every half cycle to transfer power energy of the battery to the load. That is, one switch is turned ON to apply the power supply voltage to the transformer and twice the power supply voltage to the collector of the opposite switch. Therefore, when the power supply voltage is high, care must be taken when selecting components. In general, in the case of generating an AC voltage using a vehicle battery, a high boost ratio is required, and the input terminal current is considerably large because the input terminal voltage is low. In such a power converter, the addition of one switch results in enormous conduction losses. Therefore, in a power circuit requiring a low voltage input and a high voltage output, a push pull converter having a merit of reducing the conduction loss in the case of a large current is applied as a single switch.

When all of the batteries are discharged, the batteries need to be charged, and a separate charger is required, and the charging is usually performed by applying a forward converter.

As shown in FIG. 1 (b), when the main switch is turned on at the same time, the forward converter is applied with the power supply voltage to the primary side of the transformer, and thus the voltage generated in the secondary winding is rectified through the output diode. It is smoothed by the output filter and supplied to the load. In this way, if the main switch is turned off while power is being supplied to the load, the energy and excitation energy accumulated in the leakage inductance of the transformer are returned to the input power source through the reflux diode. At this time, the primary winding voltage of the transformer is clamped to the input power supply voltage by the reflux diode, so the voltage across the main switch becomes the power supply voltage, and the circuit forming the current path is composed of two switches. The saturation voltage of can be ignored. Therefore, the forward converter is a suitable circuit when the input supply voltage is high.

However, in the push pull converter and the forward converter, since energy transfer is transferred from the input side to the output side, the inverter function and the charger function are operated separately, and the user has to purchase and use the inverter and the charger separately. There is discomfort.

Therefore, the present invention has been devised to solve the above problems, and in using a mobile power supply, an AC high voltage is output using the DC low voltage of the battery, and at the same time, the operation of charging the battery using the AC voltage is performed. Since it consists of one product, it aims to provide the inverter combined charger which can be used simultaneously as an inverter and a charger in one product.

In addition, another object of the present invention is to provide an inverter combined charger in which the system is automatically turned off when the battery is over discharged and when the battery is overcharged.

1 is a circuit diagram of a DC / DC converter according to the prior art.

Figure 2-overall system configuration of the inverter combined charger according to the present invention.

3-Circuit diagram of a DC / DC converter capable of bidirectional power transfer.

4-Circuit diagram of a full bridge inverter capable of bidirectional power transfer.

5-Thevenin's equivalent circuit diagram for load current.

<Explanation of symbols for the main parts of the drawings>

100: bidirectional DC / DC converter 110: push pull converter

111: transformer 120: forward converter

121: capacitor 130: full bridge inverter

140: converter control unit 150: inverter control unit

160: mode selection switch 170: mode selection switch

180: start switch 181: DC power indicator

182: storage battery 183: inverter light

184: fault indicator 185: AC output indicator

186: AC input indicator 187: charging indicator

188: Charging complete indicator

The present invention for achieving the above object is a push-pull converter capable of DC / DC power conversion in one direction; A forward converter capable of DC / DC power conversion in one direction; A converter controller for controlling the push pull converter and the forward converter to operate as a single DC / DC converter having bidirectionality to form a stable DC power source; A full bridge inverter capable of bidirectional power transfer; An inverter controller which controls the full bridge inverter to convert the output of the push pull converter into a stable AC power source, or operates the full bridge inverter as a bridge rectifier circuit to apply the rectified output as an input of the forward converter; And a mode selection switch that is interlocked to determine the inverter mode and the charger operation mode. When the inverter mode is selected, the DC low voltage of the battery is converted into a stable DC high voltage by the control of the push-pull converter and the converter control unit. Is output at a stable AC voltage under the control of the full bridge inverter and the inverter control unit. When the charger operation mode is selected, external AC power is converted into a stable DC voltage under the control of the full bridge inverter and the inverter control unit. As a technical gist of the inverter, a charger using an inverter which forms a stable direct current low voltage under the control of the forward converter and the converter control unit and is charged in a storage battery.

Here, the push pull converter and the forward converter are preferably configured to share a transformer.

When the inverter mode is selected, the inverter control unit receives an output AC power of the full bridge inverter and transmits a feedback control signal to the converter control unit when the voltage, current, and waveform form are below a set value. It is preferable that the control signal is sent to the controller so that a stable AC power is output, and the operation is stopped when the charger operation mode is selected.

In addition, when the charger operating mode is selected, it is preferable that the charging method is configured to include a method selection switch selectable by the constant current charging or constant voltage charging.

Accordingly, an inverter mode is selected to output a low voltage of the battery as a stable sinusoidal AC voltage, and a charger operation mode is selected to connect an external AC external power source to charge the battery as an advantage.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is an overall system configuration diagram of a combined charger charger according to the present invention, Figure 2 is a circuit diagram of a DC / DC converter (hereinafter referred to as a bi-directional DC / DC converter) capable of bi-directional power transfer, Figure 4 is a bi-directional power transfer 5 is a circuit diagram of a possible full bridge inverter, and FIG. 5 is a Thevenin equivalent circuit diagram for a load current.

As shown, the inverter combined charger according to the present invention is largely the push pull converter (110), the forward of the push pull converter (110) as the output terminal, the output terminal as the input terminal forward (Forward) The converter 120 is a bidirectional DC / DC converter 100, the full bridge inverter 130, the converter control unit 140, the inverter control unit which is integrated by sharing the transformer 111, which enables power transfer in both directions And a mode selection switch 160 and a mode selection switch 170.

First, the configuration and role of each device when operating as an inverter will be described.

When the inverter mode is selected by using the mode selection switch 160 and the start switch 180 is turned on, the DC power indicator 181 lights up and the bidirectional DC / DC converter 100 connected in series with the battery 182. Receives the DC power of the storage battery 182. At this time, the converter control unit 140 connected in series with the storage battery 182 receives the voltage value Vs and the current value Is of the storage battery 182 and compares it with a preset value set in the converter control unit 140. The converter control unit 140 operates the push pull converter 110 as a boost converter to form a high voltage from the low voltage of the storage battery 182. The converter controller 140 transmits the energy of the storage battery 182 to the transformer 111 by turning on and off the transistors Q1 and Q2 of the push-pull converter 110 at appropriate intervals. The voltage induced to the secondary side of the transformer 111 is rectified by a bridge rectifier circuit formed of the diodes D1 and D2 of the forward converter 120 and the freewheeling diodes D3 and D4 of the transistors Q3 and Q4. It is applied to both ends of the capacitor 121. Therefore, the DC link voltage and V _DC are formed at both ends of the capacitor 121. At this time, the converter control unit 140 detects the output current, Io of the V _DC or the bridge rectifier circuit, compares it with a setting value, and then controls the ON and OFF periods of the transistors Q1 and Q2 so that V _DC or Io matches the setting value. . That is, the feedback voltage is controlled to control the switching widths of the transistors Q1 and Q2 so that the DC link voltage V _DC is stably output regardless of the fluctuation of the input power or the load of the storage battery 182.

When the V _DC link voltage equal to the set value is stably output from the push pull converter 110 operated as the boost converter, the voltage is transferred to the full bridge inverter 130. The full bridge inverter 130 is operated using the stable voltage V _DC transmitted from the bidirectional DC / DC converter 100 as an input source, and the inverter controller 150 is connected in series to the full bridge inverter 130. The output voltage of the full bridge inverter 130 is controlled.

When the command value of the output voltage from the inverter control unit 150 is positive, the transistors Q _A and Q _D of the full bridge inverter 130 are turned on to generate a positive output voltage, but when the transistors Q _A and Q _D are turned off, the full bridge When the output current of the inverter 130 is positive, the output current flows through D _B and D _C. Therefore, the polarity of the output voltage is added until the output current becomes zero. If the output current is negative, the current loop through D _A and D _D is negative. Due to this, the output voltage polarity is added. Therefore, when all the transistors are turned off, the polarity of the output voltage depends on the polarity of the output current.

Therefore, in order not to be affected by the output current, the inverter controller 150 transmits a control signal to turn off the transistors Q _A and Q _D that were turned on to generate a positive output voltage and to turn on the Q _B and Q _C at the same time. Control to output negative output voltage. Therefore, the inverter controller 150 turns on and off the transistors Q _A , Q _D , Q _B , and Q _C of the full bridge inverter 130 according to the polarity of the output voltage to be generated. AC is output at the output.

The inverter control unit 150 controls the switching cycle of the transistors Q _A , Q _B , Q _C , Q _D of the full bridge inverter 130 to output DC input power input to the full bridge inverter 130 input terminal. Convert it to a power source and output it. When the full bridge inverter 130 is operated, the inverter controller 150 controls the inverter indicator light 183 to be turned on. And the output current (I _1O, I _C2) and output voltage (V _C) at the output terminal of the full bridge inverter 130 is transmitted to the inverter controller 150 does not reach the set value compared to the set point of the inverter controller 150 If not, it sends a control signal to the converter control unit 140 and the full bridge inverter 130.

The converter control unit 140 receives the control signal of the inverter control unit 150 to control the output voltage by controlling the switching widths of the transistors Q1 and Q2 of the bidirectional DC / DC converter 100 to the full bridge inverter 130. The transferred control signal controls the switching widths of the transistors Q _A , Q _B , Q _C , and Q _D to output a stable sine wave.

Here, the output current control method of the full bridge inverter 130 detects the capacitor current (I _C2 ) at the output terminal and performs a delta (DELTA) modulation by using the value and the value of the inverter controller 150 as an input variable. In addition, the inverter controller 150 is configured to output a sinusoidal wave with improved THD. Here, when the battery 182 is over-discharged during the above process, the fault indicator 184 lights up and the system is turned off under the control of the converter controller 140. ) Damage is prevented. Then press the reset switch to restart the system.

The sinusoidal AC power output from the full bridge inverter 130 through the above process passes through a filter formed by the coil L ₁ and the condenser C ₂ and is then output to the AC output unit. At this time, the AC output indicator 185 is turned on.

The following describes the configuration and role of each device when operating as a charger.

Connect the AC input terminal to an external power source, select the charger operation mode in the mode selector switch 160, select one of constant voltage charging, constant current charging, or rapid charging in the method selector switch 170, and then start the switch ( 180) ON. When the start switch 180 is turned on, the AC input indicator 186 is turned on, and the external AC power is input to the input terminal of the full bridge inverter 130 after passing through the capacitor C ₂ and the coil L ₁ .

At this time, the inverter control unit 150 is applied with an AC power to the overcurrent detection unit of the inverter control unit 150, the inverter control unit 150 is interlocked and does not operate, so the inverter indicator light 183 maintains the OFF state. That is, the transistors Q _A , Q _B , Q _C , Q _D of the full bridge inverter 130 are stopped, and diodes D _A , D _B , D _C , D _D form a bridge rectifier circuit, and are transmitted through the input unit. Convert AC power to DC power and output it to the output terminal.

The DC power delivered to the output terminal of the full bridge inverter 130 is transmitted to an input terminal of the bidirectional DC / DC converter 100, that is, to an input terminal of the forward converter 120. Transistors Q3 and Q4 forming the forward converter 120 receive and control the control signal of the converter controller 140 to transfer DC power delivered to the input terminal of the bidirectional DC / DC converter 100 to the transformer 111. .

Since the low voltage and the high current are required to charge the storage battery 182, the converter controller 140 operates the bidirectional DC / DC converter 100 as a step-down forward converter 120. In order to operate in this way, the transistors Q1 and Q2 are interlocked, and the freewheeling diodes built in the transistors Q1 and Q2 form an onion rectifier circuit, and charging of the storage battery 182 is started. At this time, when charging of the battery 182 starts, the charging indicator 187 is turned on.

Here, the converter controller 140 detects the voltage Vs and the current Is of the output terminal of the bidirectional DC / DC converter 100, that is, both ends of the battery 182, and compares the set value with the previously set value. In this case, a control signal is sent to the transistors Q3 and Q4 of the bidirectional DC / DC converter 100. By the control signal, the switching widths of the transistors Q3 and Q4 are controlled to output the voltage and current corresponding to the set value. When the output voltage matches the set value, the stable DC power is output and the battery 182 is charged.

When the battery 182 is fully charged through the above process, the charge completion indicator 188 is turned on, and when overcharged or abnormal, the system is automatically turned off by the action of the interlock, the fault indicator 184 is turned on. After resolving this, the system is configured to restart only by pressing the reset switch.

The present invention by the above configuration, the inverter action and the charger action is configured in a single device to operate the rod using a battery, and when the battery is discharged can be immediately charged by using an AC power source separately from the inverter and the charger There is an effect that the hassle to be provided is eliminated.

In addition, by adopting the feedback control and the delta modulation method in the control method, there is an effect that the starting characteristic and the dynamic characteristic are remarkably improved.

When the inverter mode is selected or when the charger operation mode is selected, the interlock due to overcharge, over discharge, and over current is installed separately, and even if one of them is applied, the system operation is automatically stopped. This also has the effect of being prevented.

Claims (4)

A push pull converter 110 capable of DC / DC power conversion in one direction; A forward converter 120 capable of unidirectional DC / DC power conversion; A converter control unit 140 for controlling the push pull converter 110 and the forward converter 120 so as to operate as a single DC / DC converter having bidirectionality to form a stable DC power source; A full bridge inverter 130 capable of bidirectional power transfer; The full bridge inverter 130 is controlled to convert the output of the push pull converter 110 into a stable AC power source, or the full bridge inverter 130 is operated as a bridge rectifier circuit to convert the rectified output into the forward converter ( An inverter controller 150 applied as an input of the 120; It is composed of a mode selection switch 160 that is interlocked to determine the inverter mode and the charger operation mode, When inverter mode is selected, The direct current low voltage of the storage battery 182 is converted into a stable direct current high voltage by the control of the push pull converter 110 and the converter control unit 140, and the direct current high voltage of the full bridge inverter 130 and the inverter control unit 150 is changed. Output by stable AC voltage by control, When the charger operation mode is selected, The external AC power is converted into a stable DC voltage by the control of the full bridge inverter 130 and the inverter controller 150, and the DC voltage is a DC which is stable by the control of the forward converter 120 and the converter controller 140. The inverter combined charger, characterized in that to form a low voltage to charge the battery 182. The charger as claimed in claim 1, wherein the push-pull converter (110) and the forward converter (120) share a transformer (111). The method of claim 1, wherein the inverter controller 150, When the inverter mode is selected, when the output AC power of the full bridge inverter 130 is applied and the voltage, current, and waveform form are less than the set value, a feedback control signal is sent to the converter controller 140, and a full bridge inverter ( 130) to send a control signal to output a stable AC power, Inverter-compatible charger characterized in that the operation is stopped when the charger operation mode is selected. The charger as claimed in claim 1, further comprising a method selector switch (170) for selecting a charging mode as a constant current charging or a constant voltage charging.