JPH06245501A - Power device - Google Patents

Abstract

PURPOSE:To miniaturize a device by simplifying the constitution of a detector and a control circuit in the power device converting power in the bidirections. CONSTITUTION:A power device has a first inverter 21 being connected to first power terminals 11, 12 and converting power in the direction of second power terminals 13, 14 having different voltage and a second inverter 22 being connected to the second power terminals 13, 14 and converting power in the direction of the first power terminals 11, 12, and load is bonded with the first or second power terminals. A detector 1 detecting the currents and voltage of the first inverter 21 and a control circuit 2 controlling the first or second inverters 21, 22 on the basis of the detecting signal of the detector 1 are provided.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention can be used for a power supply device capable of bidirectionally converting power and for controlling power supplied to each load according to load fluctuation.

[0002]

2. Description of the Related Art FIG. 5 is a circuit diagram of a conventional example. This circuit
Is designed to enable bidirectional power conversion between the A side and the B side.
It is made, and the capacitor C on the side of the instep₁DC power source E₁
Or the load is connected. Capacitor C₁The positive electrode of
Inductor L₁Through the high frequency transformer T₁Instep winding
Is connected to the middle tap. At both ends of the instep winding,
Transistor Q respectively₁, Q₂The collector of is connected
ing. Each transistor Q₁, Q₂The emitter of
Densa C₁Is connected to the negative electrode of. In addition,
Densa C₂DC power source E₂Or the load is connected
It Capacitor C₂Inductor L is connected to the positive electrode of₂Through
High frequency transformer T₁Connected to the middle tap of the second winding of
ing. Transistor Q is connected to both ends of the winding on the second side.
₃, Q_FourThe collector of is connected. Each transistor
Q₃, Q_FourThe emitter of is the capacitor C₂Connect to the negative electrode of
Has been done. Each transistor Q₁~ Q_FourCollector's
Between the mitters, each diode D₁~ D_FourIs antiparallel
It is connected. Inductor L ₁The secondary winding of the
The circuit 1a is connected and the control signal
Path 2b is transistor Q₃, Q_FourGenerates the control signal of
Transistor Q via drive circuit 3b₃, Q_FourIs driven
Be done. Also, inductor L₂The secondary winding has a detection circuit
1b is connected to the control circuit 2 according to the detection signal.
a is transistor Q₁, Q₂Generates and drives the control signal of
Transistor Q via circuit 3a₁, Q₂Is driven
It

[0003]

In the above-mentioned conventional example, when the power conversion is performed from the A side to the B side and the supplied power is controlled depending on the state of the load connected to the B side, the B side is connected to the B side. The load current I ₂ was detected by the inductor L ₂ thus fed, and this was fed back to the control circuit 2a of the inverter on the side of A to send a control signal to the inverter on the side of A. On the other hand, when the power conversion from the B side to the A side is performed to control the power supplied to the load connected to the A side, similarly, the load current I ₄ is detected by the inductor L ₁ and the load current I ₄ is detected. The feedback was applied to the control circuit 2b of the inverter of the above, and the control signal was sent to the inverter on the other side.
Therefore, the detection circuits 1a and 1b on both sides
And control circuits 2a, 2b and their power supply circuits are required,
Moreover, insulation of the detection circuits 1a and 1b is also required. This has been a major obstacle to downsizing of the device.

The present invention has been made in view of the above points, and an object thereof is to simplify the configurations of a detection circuit and a control circuit in a power supply device that bidirectionally converts power. Especially.

[0005]

In order to solve the above-mentioned problems, in the power supply device of the present invention, as shown in FIG. 1, the first power supply terminals 11 and 12 are Different second power supply terminals 13 and 14, a first inverter 21 connected to the first power supply terminal to convert electric power in the direction of the second power supply terminal, and a first power supply terminal connected to the second power supply terminal A second inverter 22 for converting electric power in the direction of the power supply terminal of the first power supply terminal and a load connected to the first or second power supply terminal, and detecting the current and voltage of the first inverter 21. A circuit 1 and a control circuit 2 for controlling the first or second inverter 21, 22 based on the detection signal of the detection circuit 1 are provided.

[0006]

In the circuit shown in FIG. 1, the inverter 21 on the instep side is
More power can be converted from Party A to Party B, and
Inverter 22 performs power conversion from B side to A side
be able to. Now, the switch of the inverter 21 on the instep side
Element Q₁, Q₂Switching operation of the transformer
T₁When the power is converted to the other side via the
Current I depending on the condition₁Changes. This
Inductor L ₁Is detected by the detection circuit 1 connected to
A control signal suitable for the instep side inverter 21 from the control circuit 2
Send out. At this time, the switch SW1 is energized to the B side.
Has become. As a result, the load connected to the B side is output.
The input power can be detected and controlled on the instep side.
It Next, in case of power conversion from B side to A side, B side
Switching element Q of the inverter 22 of₃, Q_FourThe sui
And the transformer T₁Power to the instep side via
At the time of supply, the state of the power source on the other side or
Current I depending on the state of the load connected to the_FourChanges.
This is inductor L₁Detected by the detection circuit 1 connected to
Then, the control circuit 2 sends a control signal to the B-side inverter 22.
Put out. At this time, the switch SW1 is energized to the A side.
It

[0007]

FIG. 2 is a circuit diagram of an embodiment of the present invention. Former
DC power source E on the side₁Load circuit 4 powered by
Converters are connected in parallel. Where DC power supply
E ₁Is generally a commercial power source that has been rectified and smoothed.
On the other hand, on the other side, DC power supply E ₂Inver powered by
Is connected. Here, DC power supply E₂Can be charged and discharged
Use a rechargeable battery. When converting power from the side A to the side B
In other words, that is, the secondary battery E from the commercial power source side₂Charge to
Sometimes the charging current I₂Is the input current I on the instep side₁And correlation
Input current I₁Is the inductor L₁And its second volume
Detected by the detection circuit 1 connected to the line, the control circuit
2, the control signal is sent to the inverter on the instep side
It At this time, the switch SW1 is energized to the B side.
Now DC voltage V₁Is constant, charging current I₂Is 2
Secondary battery E₂Input current I₁
Also changes according to this condition. Therefore, after full charge
Input current I₁Input to prevent overcharging
Current I₁Control signal to control the instep side inverter
Just send it out. Alternatively, DC voltage V₁Do not keep
If not, the battery voltage V after full charge₂Rises once and then falls
This battery voltage V₂Change of the instep
Current voltage V₁It is also possible to detect by.

On the other hand, DC power source E₁From the other side
When converting power to the instep side, that is, the secondary battery E₂Released from
Power and supply power to the load circuit 4 connected to the instep side
Discharge current I₃Is the output current I on the instep side_FourIs correlated to
It Output current I on this side_FourIs the inductor L₁And its
To the control circuit 2 via the detection circuit 1 connected to the secondary winding
Is sent. At this time, the switch SW1 is energized to the A side.
ing. Also, the battery voltage V₂Is a transformer T₁To the turns ratio
DC voltage V on the instep side with a proportional value₁Correlation with
Force current I_FourTogether with voltage V₁Is also detected by the detection circuit 1.
receive. Battery E ₂Battery capacity decreases as battery capacity decreases
V₂Decreases and the discharge current I₃Also decreases. For this reason,
Instep side voltage V correlated to these₁And output current I_FourModen
Pond E₂It will decrease as the capacity of the
Voltage V on the instep side so that it will not be discharged₁Or output power
Flow I_FourWhen the value becomes less than the specified value,
Sends a control signal to stop the operation. Furthermore, on the instep side
The current flowing to the connected load circuit 4 (the output current I on the instep side
_FourIs almost the same value) as the battery voltage V₂Decrease with decreasing
Battery voltage V₂Or discharge current I₃To
Battery E is detected on the instep side₂Even if the capacity of the
Send a constant control signal to the B-side inverter
It

FIG. 3 shows an example of the detection circuit 1. In this circuit, the voltage of the smoothing capacitor C ₁ of the DC power source E ₁ is divided by the resistors R ₁ and R ₂ and applied to the positive input terminal of the comparator CP. In addition, the voltage of the capacitor C ₁ is changed to the resistance R
_The reference voltage applied to the Zener diode ZD via ₃ and generated across the Zener diode ZD is applied to the negative input terminal of the comparator CP. The operating voltage of the comparator CP is supplied from the capacitor C ₁ . The output voltage of the comparator CP becomes the voltage detection signal of the capacitor C ₁ . On the other hand, the voltage generated in the secondary winding of the inductor L ₁ is half-wave rectified by the diode D ₅ and charged in the capacitor C ₄ . A discharging resistor R ₄ is connected in parallel to the capacitor C ₄ . The voltage generated in the capacitor C ₄ becomes a detection signal of the current flowing in the inductor L ₁ .

In the above embodiment, when the electric power is converted from the side B to the side A, the battery is discharged and power is immediately supplied to the load. In this way, however, the power is immediately supplied to operate the load. Instead, operate the B-side inverter under a certain switching operation for a certain period of time in the initial stage,
The output power is detected by the detection circuit on the A side, the preset power supply is compared with the output power in the proper state, and the control signal matching that state is sent to the B side inverter to perform this operation. You may move to. At this time, the electric power output to the instep side for a certain initial period is at a low level such that the load does not operate. By performing such an operation, for example, when the voltage of the battery, which is the power source on the other side, is significantly reduced, the discharge is stopped to prevent over-discharging, or a battery with a different rating is erroneously connected. Also in this case, there is an effect of preventing the destruction and stress of other circuits by controlling the discharge or limiting the output. In addition, it is possible to detect the short-circuited state of battery life, non-connection, etc.

FIG. 4 is a circuit diagram of another embodiment of the present invention. In the present embodiment, the half bridge system is used as the instep side inverter, and the push pull system is used as the other side inverter. In the side A inverter, a series circuit of switching elements Q ₁ and Q ₂ and capacitors C ₂ and C ₃
Are connected in parallel and are connected to the capacitor C ₁ via the inductor L ₁ . Switching element Q
The upper winding of the high frequency transformer T ₁ is connected between the connection point of ₁ and Q _{2 and} the connection point of the capacitors C ₂ and C ₃ . Switching elements Q ₁ and Q ₂ are alternately turned ON / OFF
Then, a high frequency current is passed through the instep winding of the high frequency transformer T ₁ . The input power source of the upper side inverter is configured by rectifying the commercial power source Vs with the full-wave rectifier DB and smoothing it with the capacitor C ₁ .

In this embodiment, the electric power is changed from the side A to the side B.
When converting, that is, from the commercial power source Vs to the secondary battery E₂What
Charging electricity amount when charging Φ₁Is the charging current I₂× charge
Electricity time t₁Can be calculated by This is the input current I on the instep side₁
× Charging time t₁Can be correlated with. Next, turn off the commercial power supply Vs.
Comb, when converting power from the B side to the A side, that is, 2
Supplying power to the load connected to the instep by discharging from the secondary battery
Discharge electricity amount Φ₂Is the discharge current I₃× Discharge time
t₂Can be calculated by This value is also the output current I on the instep side _Four× discharge
Time t₂Can be correlated with. These two correlated quantities of electricity Φ
₁And Φ₂Is the inductor L₁And its secondary winding
Input to the separately provided arithmetic circuit 5 via the detection circuit 1,
Battery E at any time₂Remaining capacity Φ₃Can be calculated. This
Battery E when₂Remaining capacity Φ₃Is Φ₃= Φ₁-Φ₂so
It can be calculated. Also, at this point, the battery E₂
To charge the battery to full charge.₂Full charge
State capacity Φ to remaining battery capacity Φ₃Or charge the value
If you think that charging with a constant charging current,
The charging time Tch is Tch = {(fully charged battery capacity Φ) − (battery remaining capacity Φ
₃)} / I₁ Can be found at. In the above formula, I₁Is the charging current
I₂Is the input current on the instep side that is correlated with. Therefore, there is
Charging time Tc after discharging for a certain period until the next full charge
The invertor side inverter is operated only during h and the charging current I₂To
Secondary battery E₂It would be good if it is thrown away. By this
Therefore, overcharging can be prevented. Also, it may cause over discharge.
The remaining battery capacity corresponding to the battery voltage
The inverter on the other side when it falls below this level during discharge.
Sends a control signal to stop the operation of the₂Over discharge
Can be prevented in advance.

In the above embodiment, the charging current I₂And discharge
Current I₃Explained under the condition that each is constant
However, these charging and discharging currents are
When changing to or changing to
To do. The amount of electricity charged to the battery Φ ₁Changes over time
Charging current I₂(T), charging time is t₁given that, Can be expressed as Next, the amount of electricity discharged from the battery Φ₂Is the time
The discharge current that changes together is I₃(T), discharge time is t₂
given that, Can be expressed as Charging time t₁, Discharge time t₂Battery remaining after
Capacity Φ₃Is Φ₃= Φ₁-Φ₂ Can be expressed as Here, the battery capacity when the battery is fully charged
Let Φ be Φ−Φ₃Is the amount of electricity consumed
The next time you charge it, Φ-Φ₃Charge an amount equivalent to
The charging current at that time is I₂(T) and
Then, the time Tch required for charging is Tch = (Φ−Φ₃) / I₂(T) = (Φ-Φ₁+ Φ₂) / I₂(T).

In the above equation, I ₂ (t), I ₃ (t),
Φ is I ₁ (t) and I ₄ by the detection circuit 1 on the instep side, respectively.
Since (t), Φ ₀ can be correlated, Becomes By increasing the value of I ₁ (t), the time Tch required for charging becomes shorter, so that rapid charging is possible. In addition, in FIG. 4, the half bridge method is adopted for the instep side inverter, but the inverter method is
There is no problem even if other methods are used for both Party A and Party B.

[0015]

According to the power supply device of the present invention, in the power supply device capable of bidirectional power conversion, it is possible to detect and control either one of the input power and the output power. The circuits can be integrated into one, which has the effect of simplifying the circuit and downsizing the device.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a basic configuration of the present invention.

FIG. 2 is a circuit diagram of an embodiment of the present invention.

FIG. 3 is a circuit diagram of a detection circuit used in an embodiment of the present invention.

FIG. 4 is a circuit circuit diagram of another embodiment of the present invention.

FIG. 5 is a circuit diagram of a conventional example.

[Explanation of symbols]

1 detection circuit 2 control circuit 3a drive circuit 3b drive circuit C ₁ capacitor C ₂ capacitor L ₁ inductor L ₂ inductor Q ₁ switching element Q ₂ switching element Q ₃ switching element Q ₄ switching element T ₁ high frequency transformer

Claims (1)

[Claims] 1. A first and a second power supply terminal having different voltages, a first inverter connected to the first power supply terminal for converting electric power in the direction of the second power supply terminal, and a second power supply terminal. A second inverter connected to the first power supply terminal for converting electric power in the direction of the first power supply terminal, and a load connected to the first or second power supply terminal. And a control circuit for controlling the first or second inverter based on a detection signal of the detection circuit.