KR0137845B1 - Integrated type high frequency charger - Google Patents

Abstract

The present invention improves the power factor and efficiency of the conventional charger and discharger, reduces the size, and integrates the charge / discharge function. The main circuit configuration of the integrated charger / discharger is capable of two-way power transmission with a three-phase SPWM AC / DC converter unit. Phase Shift ZVS-FB consists of DC / DC converter section, and the three-phase SPWM AC / DC converter section improves input power factor and input current waveform, configures bi-directional power, and enables bi-directional power transfer. Phase Shift ZVS-FB DC / DC converter is configured to enable bi-directional power transfer to ensure electrical isolation and high efficiency.

Compared to the conventional charger / discharger (Dyster Rectifier), the device is smaller (more than 30%), lighter (more than 50%), and the efficiency is improved (more than 3%). The present invention relates to an integrated charger and discharger that minimizes external appearance.

Description

Integrated high frequency charger / discharger

1 is a circuit diagram of a conventional charger and discharger.

2 is a circuit diagram of another conventional charger / discharger.

3 is an integrated high-frequency charging and discharging main circuit diagram according to the present invention.

4 is a block diagram of a main circuit and a control circuit of a charger / discharger AC / DC input unit 3ψ SPWM converter according to the present invention.

FIG. 5A shows the operation principle of the three-phase SPWM converter main circuit of FIG.

(B) of FIG. 5 is an operating waveform of the three-phase SPWM converter of FIG.

(C) of FIG. 5 is an operation phase vector diagram of the three-phase SPWM converter of FIG.

6 is a main circuit diagram of the charger / discharger DC / DC converter according to the present invention.

FIG. 7A is an equivalent circuit of a DC / DC converter in the charging operation of FIG.

FIG. 7B is an equivalent circuit of the DC / DC converter in the discharge operation of FIG.

FIG. 8 is a timing diagram of a forward conversion operation (charging) of a primary bridge of a DC / DC converter unit capable of receiving power in both directions.

9 is a timing diagram of the reverse conversion operation (interruption) of the secondary bridge of the DC / DC converter section capable of receiving power in both directions.

10 is a block diagram of a DC / DC converter unit and a control circuit capable of receiving power in both directions.

The present invention relates to an integrated high frequency charger / discharger, which will be described in more detail. ) It is composed of AC / DC converter part and composed of Phase-Shift Phase-Shift ZVS-FB (Zero Votage Switching-Full Bridge) DC / DC converter for high efficiency and electrical isolation. The present invention relates to an integrated high frequency charger / discharger having a small size, light weight, and high power factor.

In general, a conventional charger / discharger, as shown in FIG. 1, has a step-down transformer (1) for electrical insulation at an input, and a variable output voltage, current and power can be converted from an AC commercial power supply to a DC, and a DC Rectifier (2) for converting power from the side (battery: battery) to the AC power source, and a magnet contactor (3) that reverses the output voltage-polarity to reverse the power to achieve reverse conversion of the power. Consists of.

In addition, another conventional charger / discharger uses the step-down transformer 4 as shown in FIG. 1 to electrically insulate the input as shown in FIG. 2, and the output voltage polarity conductive magnet contact for power reverse conversion. In order to improve the disadvantage of using magnet contactor, it consists of two thyristor six pulse converters (5), and the AC / DC converter acts as a rectifier during the pure operation, so that power is transferred from AC commercial power source to DC (Battery). The gate pulse of the converter 1 (51) is interrupted during the reverse conversion, and the converter 2 (52) is operated as an inverter mode, so that the output voltage polarity is the same, but only in both directions of the current (id) are reversed. It is configured to be.

The conventional charger / discharger configured as shown in FIG. 1 and FIG. 2 has the following problems.

1) When the thyristor phase angle is changed, the fundamental wave phase angle of the AC input current is equal to the firing angle, and not only the corresponding harmonic reactive power but also the fundamental wave reactive power are generated to generate the input current is. Has a distorted waveform, thus exhibiting low input power factor characteristics.

2) The circuit consists of a step-down transformer, a thyristor rectifier, and an LC filter, which has the advantage of low cost, but is bulky and heavy, making it difficult to manufacture and install with a large-capacity charger, Low noise, especially in the step-down transformers and reactors has a big disadvantage.

3) DC output voltage (Vd) is limited in inverter mode due to the minimum firing angle requirement of converter 2 (52) when converter 2 (52) is operated in inverter mode. There is this.

4) There is a possibility of current failure in inverter mode due to disturbance of AC input power.

In addition, in recent years, as the information society progresses, DC power supplies that use storage batteries have been increasing. In general, chargers employing semiconductor devices such as thyristors and diodes are shown in FIG. (Figure 2) Since it contains a lot of harmonic currents, the harmonic currents are introduced into the power supply, causing harmonic disturbances such as malfunctioning electronics.The IEC is considering the replacement of harmonic rectification in TC77. This regulation can be a big factor in trade barriers.

Therefore, it is necessary to develop a product that can meet the IEC standard, and the miniaturization, light weight, low noise, and high efficiency of the charger are greatly required according to the development and spread of IGBT, Power Mosfet, etc., which are elements in the high-speed switching peninsula of power electronics. have.

The present invention was invented to overcome the shortcomings of the conventional charger and discharger, and the three-phase sinusoidal pulse width modulation (SPWM) AC / DC converter unit 6 and the ZVS-FB PWM DC / DC converter unit capable of two-way power transfer (7). The purpose of the present invention is to provide a charger / discharger consisting of a three-phase sinusoidal pulse width modulation (SPWM) AC / DC converter (6) while controlling the AC input current to a sinusoidal wave 5% or less harmonic distortion, power factor 0.95 The ZVS-FB PWM DC / DC converter unit 7, which can be maintained abnormally and configured to allow bidirectional power transfer, and which can operate bidirectional power transfer, operates at a high sweeping frequency, thereby providing a high frequency transformer for electrical isolation from the input power supply side. It can be used to make the charger small, high efficiency and low noise.

With reference to the accompanying drawings will be described in detail the charging and discharging embodiment according to the present invention.

1) 3-phase sine wave pulse width modulation (SPWM) 3-phase sine wave pulse width modulation (SPWM) applied to AC / DC converter main circuit part and control circuit part integrated high frequency charge / discharger AC / DC input part The DC converter 6 charges the energy of the battery from the AC commercial input power source 20 and discharges the AC commercial input power source 20 again, while controlling the AC input current to a sine wave, while harmonic distortion rate 5%. Hereinafter, it is used as a means for obtaining a power factor of 0.95 or more, and the main circuit configuration consists of a three-phase boost inductor 9 and a three-phase voltage source converter 10.

Mode 1. Three-phase converter when the three-phase converter switch (T ₁ ) is turned off (Turn-off), and the switch (T ₂ ) is turned on (Tun-on) → step-up inductor (L _R ) The switch T ₂ becomes a short-circuit mode of the three-phase power source, whereby the inductor current rises, and its energy is accumulated in the magnetic field of the boost inductor L _R.

A diode (T D ₁₎ on the top of the leg (leg) on banbyeon may be reverse biased, and the output capacitor (C _O) is supplied to an electric power to a load (DC / DC converter unit).

Mode 2. As soon as the three-phase AC / DC converter switch (T ₂ ) is turned off, the energy accumulated in the boost inductor (L _R ) is combined with the energy from the AC commercial input power source (20). through ₁ D) is applied to the output capacitor (C _O).

Here, if the switching frequency is much higher than the frequency of the input voltage, equations (1) and (2) can be enclosed by d ', which defines the average turn-off duty ratio of the switch in one switching period. have.

Where Mode 1; d '= 0, Mode 2; d '= 1.

Assuming that the input phase voltage V _R for one phase is a sine wave, the fundamental wave frequencies of Vconv = Cd'Vo and I _R are respectively as shown in (b) and (c) of FIG. It can be expressed as

At power frequency ω = 2π f Arbitrarily as If you select

The phase diagram corresponding to the above expression is as shown in Fifth (c).

In this case, the input converter I _R1 is delayed to the input phase voltage V _R by an arbitrary mounting angle θ.

Therefore, the active power P supplied to the SPWM converter by the AC source is

The reactive power Q supplied by the AC source in the phase diagram of FIG. 5C is positive and is expressed as follows.

In the equation (6), the invalid Q is the sum of the reactive power consumed by the PWM converter and the reactive power consumed by the boost inductance L _R. And if you solve for IR1

The active power (P), reactive power (Q), and supply current (LR) and reactive power (Q) required for the supply voltage VR and LR given by equations (9) and (10) are a single function of Vconv1. It can be seen.

Therefore, the magnitude and phase of the active power P, reactive power Q and power supply current LR (fundamental wave component) are uniquely determined by the pulse width modulator 17 compared to the triangular wave 16 in the control circuit. Can be controlled by Vconv1.

Therefore, in the forward conversion operation from the AC commercial input power supply 20 to the DC link output capacitor Co, the input power factor 1 can be achieved by varying Vconv1 to make θ equal to 0 (Zero). link) By controlling the magnitude and phase of Vconv1 when discharging from the output capacitor (Co) to the AC commercial input power supply 20, θ is set to -180 to control the AC input current to a sinusoidal wave at the time of discharging, thereby controlling the input power factor to almost 1. It is configured to be.

The control circuit mainly comprises a voltage compensator 12, a phase shifter 13, three multipliers 14, three independent current compensators 15 and a triangular wave generator 16, and a pulse width modulator ( It consists of 17).

The operation of this circuit assumes that the DC link output capacitor 11 is precharged with a voltage Vo large enough to reverse bias the IGBT antiparallel diode constituting the three-phase SPWM converter 10.

The output voltage is sensed by the voltage sensor LEM LV25-P 18 and compared with the reference voltage Verf.

The compared error signal Ve = Vref-Vfeed is used to maintain the output DC voltage at the level LeveL defined by the voltage compensator 12 and to have good transient characteristics.

The main purpose of the SPWM AC / DC converter unit 6 is to maintain the sinusoidal input current waveform in the input phase voltage and in phase (for forward conversion operation) or inverse (for reverse conversion). The input phase voltage is sensed by the transformer 19 to obtain three reference waveforms V _R , V _S , and V _T , and phase sensing of the phase shifter 13 is commercially available. In order to compensate for the phase difference angle and the power factor correction of the input power supply 20 and the sensed voltage.

The sensed voltage is obtained by multiplying the control signal Ve of the voltage compensator 12 to form the three-phase current command signal lcom (lcom = Ve · ksinwt).

In the forward conversion operation of the SPWM AC / DC converter 6, the three-phase current command signal lcom is sinusoidal and is in phase with the input phase voltage.

The current flowing through the actual input boost inductor 9 estimates the current command signal Icom almost accurately in the current compensator 15 (Ie = Ifeed-Icom), and compares the estimated control signal Ie with the triangular wave generator 15. By controlling the pulse width by comparison and supplying power to the rear-end DC / DC converter section 7, the system is operated while keeping the input power factor of 1 at almost the AC input current.

The reverse conversion operation of the SPWM AC / DC converter 6 is a phase-shifted phase-delay circuit for discharging the energy of the battery to the final voltage in the DC / DC converter unit 7 during the reverse conversion operation (during discharge). The control signal Ve of the voltage compensator 12 becomes negative by applying a constant output voltage larger than the output voltage Vo by the reference voltage Verf of the SPWM AC / DC converter 6 during constant current discharge. The three-phase current command signal Icom = -Ve ksinwt is also in reverse phase with the phase voltage, and the current flowing through the actual input step-up inductor 9 operates by estimating the three-phase current command signal Icom to perform reverse conversion operation. In addition, it operates while maintaining the input power factor of 1 while controlling the AC input current with a sine wave.

2) ZVS-FB DC / DC Converter and Control Circuit

In the present invention, it is possible to reduce the size and weight of the electrical insulation and transformer in order to have a charge and discharge function while using the charger as it is, bi-directional DC / DC converter to stabilize the voltage and current and high functionality of the charge and discharge system 6 as shown in FIG. 6, and when charging, the voltage supplied from the 3-phase SPWM AC / DC converter 6 to be supplied to the battery as a constant current (or constant voltage) through a high frequency transformer for electrical insulation. The secondary bridge 21 switches the phase shift circuit and the secondary bridge 22 does not give the IGBT gate signal, so the secondary bridge 22 is the IGBT. By making the anti-parallel diode act only as a rectifier, a forward conversion operation is performed. At this time, the phase delay circuit operation of the primary bridge 21 is as follows.

The secondary side of the high frequency transformer H. F TR by causing the gate signals for the switches Q ₂ and Q _{4 of} FIG. ₆ to be phase shifted with respect to the switches Q ₁ and Q ₃ . One of the primary bridge 21 switches is controlled to be left-on at all during the time interval (ΔD) when the voltage is zero.

On the other hand, for example, when the switch Q ₁ is open, the current (leakage current) is caused to start to be challenged by the anti-parallel diode D3 of the switch Q ₃ on the same leg. Current is charged while charging the parasitic capacitance of the switch Q ₁ .

Switch leg switch (Q ₃₎ in (Leg) such as when the conductive anti-parallel diode (D3) of (Q ₃₎ can be turned on (Turn-on) from the zero voltage condition.

In addition, when the switch Q ₂ is opened, the parasitic capacitance of the switch Q ₂ is charged, and at the same time, the current flowing through the high frequency transformer is conducted through the anti-parallel diode D4 of the switch Q ₄ . .

At this time, by the conductive switch (Q ₄₎ switch (Q ₄₎ are turned on (Turn-on) in the zero-voltage condition, an alternating current switch (Q ₄₎ → the high-frequency transformer (H. F → TRO series inductor (L _1k ) → It operates to flow through the switch (Q ₃ ).

This is to solve the problem of parasitic vibration related to the existing FB-PWM converter and low impedance to circulate the current according to the leakage inductance of the high frequency transformer (H.F TR) and the series inductor (L _1k ) and the output inductor (L _b ). Provide a path.

The timing diagram (Timming) for this is shown in FIG.

When discharging, the three-phase SPWM AC / DC converter (in order to discharge the constant current from the full charge voltage of the battery to the final voltage to the AC commercial input power 20 through the three-phase SPWM AC / DC converter 6) 6) The reverse conversion operation of the ZVS-FB DC / DC converter (7) capable of bidirectional power transmission is required to supply a voltage higher than the reference voltage Vo output from the secondary bridge (22) converter (22). Phase-shift switching operation, and the primary side is configured to operate only as a rectifier by blocking the IGBT gate signal of the bridge 21.

Step-up Phase Shift Switching Mechanism is to simultaneously turn on the switch Q _a and the switch Q _c as shown in FIG. 6 and FIG. Switch (Q _c ) OFF, switch (Q _a ) and switch (Q _b ) ON (mode 2) → switch (Q _a ) OFF, switch (Q _d ) and switch (Q _b ) ON (mode 3) → switch ( Q _b ) The operation of OFF, switch (Q _c ) and switch (Q _d ) ON (mode 4) is repeated at high frequency.

Mode 1 and Mode 3 in the store energy while a current 1 _L a boost inductor (L _b) to a state so boost inductor (L _b) short-circuit through the battery (Battery) rises, mode 2 and mode 4, the battery (Battery The sum of the voltage and the voltage accumulated in the boost inductor L _b is applied to the high frequency transformer with positive or negative polarity.

Therefore, by appropriately controlling the periods of Mode 2 and Mode 4, a high frequency AC voltage boosted to the high frequency transformer H. F TR is applied, and rectified through the IGBT anti-parallel diode of the primary bridge 21. It is configured to obtain the DC output power.

The equivalent model of the bidirectional DC / DC converter is shown in FIGS. 7A and 7B.

That is, when the power is supplied from the three-phase sinusoidal pulse width modulation (SPWM) AC / DC converter unit 6 to supply energy to the battery, the bidirectional DC / DC converter as shown in FIG. It operates as a step-down converter and converts the energy up to the end-of-charge voltage of the battery into a three-phase sine wave pulse width modulation (SPWM) AC / DC converter section (6). When discharging to 20, the bidirectional DC / DC converter 7 is configured to operate as a step-up converter as in an equivalent circuit as shown in FIG.

10 is a block diagram of a control circuit of the bidirectional DC / DC converter 7 to be constructed in the present invention.

The flip-flop 23 of this control circuit has a clock generator 25 for alternately providing a pulse signal to the IGBT gate of one leg of the bridge. A delay circuit triggered by a fixed 60 kHz clock signal and divided, and slightly delayed by about 200 ns to be driven to the other side of the bridge of the flip-flop 24. The PWM signal generated by the comparator 36 by comparing the signal of 26 and the output of the sawtooth generator 27 with the constant current or constant voltage control signal of the voltage compensator 28 is a NOR gate. Input and outputted to (37), triggered by the outputted gate (Nor gate) 37 (Trailing Edge) and divided.

Dead time set circuit 29a for blocking the output signals of the flip-flops 23 and 24 to prevent the short circuit of the IGBT arm in each of the bridge converters 21 and 22. Is input to the IGBT driving circuits 38 and 39 via.

At this time, the selection of the forward conversion operation (at the time of charging) and the reverse conversion operation (at the time of discharge) is performed by enabling and disabling the AND gates 30 and 31 by the external control signal 32. can be disabled.

The minimum duty limit circuit 34 and the maximum duty limit circuit 35 have a minimum and maximum signal during charging or discharging operation, so that the phase shift control signals of the bridges 21 and 22 are armed. As is in phase or reverse phase, it is used to prevent DC component from being applied to transformer and unstable switching operation.

The output voltage sensing of the battery uses the insulated voltage transducer of the voltage sensor LEM25-P 18 to drive the direct voltage control and protection circuit 33, and the battery Inflow or outflow sensing (Sensing) is used to drive the constant current control and overcurrent protection circuit using Hall CT.

As described above, the present invention is composed of a SPWM AC / DC converter unit and a ZVS-FB DC / DC converter unit. In the DC / DC converter section, to ensure electrical insulation and high efficiency.

Therefore, compared to the conventional charger / discharger (die thruster rectification method), the device can be miniaturized (30% or more), lightweight (50% or more), improved in efficiency (3% or more), and the input power factor is maintained at about 1 The present invention relates to an integrated charger and discharger that minimizes the distortion of the waveform.

Claims (3)

One device consists of a charging function that charges the battery by generating regulated DC voltage by inputting commercial AC input power and a discharge function that discharges the energy stored in the battery to commercial AC input power. In a two-way power transfer / discharger consisting of a three-phase sine wave pulse width modulated AC / DC converter section and a face shift ZVS-FB DC / DC converter section, an inverse conversion for discharging the energy stored in the battery 8 to a commercial power supply In operation, the secondary bridge 22 switches the phase-shifted phase-shifting operation of the step-up type, that is, simultaneously turns on the IGBT switch Q _a and the switch Q _c of the secondary bridge 22 (mode 1) → switch. (Q _c ) OFF, speech (Q _a ) and switch (Q _b ) ON (mode 2) → switch (Q _a ) OFF, switch (Q _d ) and switch (Q _b ) ON (mode 3) → switch ( Q _b) OFF, the switch (Q _d) and a switch (Q _c) by repeating the operation of the oN (mode 4) a high-frequency switch In this case, the boosted high frequency AC voltage is applied to the secondary side of the high frequency transformer (H. F TR), and the boosted high frequency AC voltage is applied to the primary side bridge 21 by not giving a control signal to the IGBT gate of the primary side bridge 21. Rectified through the IGBT antiparallel diode of (21) so that the boosted AC voltage larger than the reference output from the three-phase sine wave pulse width modulated AC / DC converter unit 6 is converted to 6) Integrated high frequency charger, discharger, characterized in that to output the battery energy to the AC commercial input power. A voltage sensor (18) for sensing the output voltage from the phase shift ZVS-FB DC / DC converter (7) and comparing it with a reference voltage (V _ref ); A voltage compensator (12) for voltage compensating the error signal (V _e = V _ref -V _feed ) compared by the voltage sensor (18) to maintain the output DC voltage at a prescribed level; A phase delay circuit 13 for phase difference angle compensation and power factor correction of the voltage sensed by the commercial input power supply and the molded connection transformer 19; A multiplier (14) for multiplying the signal from the voltage compensator (12) and the phase delay circuit (13) to form a three-phase current command signal; A current compensator 15 for estimating a current command signal signaled by the multiplier 14 for the current flowing through the input boost inductor 9 (I _e = I _feed -I _com ); A triangular wave generator 16 for generating triangular waves; Control signal of the three-phase sine wave pulse width modulation AC / DC converter unit 6 comprising a comparator 17 for comparing the estimated control signal I _e with a signal from the triangular wave generator 16 to control the pulse width. The forward conversion operation and the reverse conversion operation of the phase shift ZVS-FB DC / DC converter unit 7 in which the forward and reverse conversion operations of the three-phase sine wave pulse width modulation AC / DC converter unit 6 are bi-directional power can be achieved by configuring the polarity of the voltage compensator 12, the output signal (V _e) changing arrangement, the AC input phase voltage used in accordance with the polarity of the output signal (V _R, V _S, V _T) and phase (net conversion operation: charging) Alternatively, a three-phase current command signal (I _com = V _e · ksinωt), which is in reverse phase (inverted operation during discharge), generates an AC input line current flowing through the input boost inductor 9 so that the three-phase current command signal Icom is generated. To follow the integral type, characterized in that the forward change operation and the inverse conversion operation is made continuously High frequency charger. A clock generator (25) for generating a fixed clock frequency of about 60 kHz; A flip-flop (23) triggered by a fixed clock signal of the clock generator (25) to alternately provide a pulse signal to the IGBT gate of one leg of the bridge during forward or reverse conversion operation; A fixed delay circuit 26 for delaying a time of about 200 ns to drive the IGBT gate of the other leg of the bridge; A sawtooth generator 27 for generating a sawtooth wave; A voltage compensator 28 for compensating the DC output voltage to a prescribed level; A comparator 36 for generating a PWM signal by comparing the output of the sawtooth generator 27 with the constant current or constant voltage control signal of the voltage compensator 28; A NOR gate (37) for pulse-converting the signal from the comparator (36); A flip-flop (24) triggered by a pulse conversion signal of the NOR gate (37); A dead time set circuit 29a for preventing an IGBT arm short in each bridge 21 or 22; And gates (30) (31) for selecting the operation by an external control signal such as a charge / discharge mode control signal and an over-voltage, over-current fault signal and Eanble signal; The DC component is applied to the high frequency transformer (H. F TR) by causing the arm phase shift control signals of the bridges 21 and 22 to be in phase or reverse phase by making the signals minimum and maximum during charging or discharging operations. A minimum duty limit circuit 34 and a maximum duty limit circuit 35 for preventing a loss and unstable switching operation; An integrated high frequency charging comprising a control circuit of a face shift ZVS-FB DC / DC converter section 7 composed of IGBT drive circuits 38 and 39 for switching bridges 21 and 22, Discharger.