TWI488405B - Control method for achieving power transfer between stacked rechargeable battery cells and power transfer circuit thereof - Google Patents

Description

Control method for stacking charge battery cell power transfer and power transfer circuit thereof

The invention relates to a control method for electric quantity transfer and a power transfer circuit thereof. In particular, it relates to a control method for stacking charge cells between battery cells and a power transfer circuit thereof.

Rechargeable batteries are widely used in many products, such as notebook computers, tablets, mobile phones, and even large electric vehicles. The rechargeable battery is generally composed of a plurality of rechargeable battery cells of the same specification in parallel or in series, so as to achieve a certain power supply. Although the source of each rechargeable battery cell may be the same, there may be some differences in materials or manufacturing between the rechargeable battery cells, which causes the rechargeable battery to be unbalanced during use (charging or discharging). A phenomenon occurs. The imbalance of the rechargeable battery core is easily extended to reduce the charge of the rechargeable battery, and even the rechargeable battery core is liable to reduce the service life due to overcharging. Solving the problem of unbalanced rechargeable battery cells is each rechargeable battery Important issues to be faced during the development phase.

In order to solve the above problems, many conventional techniques provide a balancing circuit to dynamically balance the power of adjacent two rechargeable battery cells. A more common method is shown in Figure 1. A schematic diagram of a conventional multi-cell core balancing circuit 10. The balancing circuit 10 includes a plurality of battery cells including a battery core 101, a battery core 102 and a battery core 103 connected in series with a controller 100. The anode of battery cell 102 is coupled to a port 122 of controller 100 via a resistor 112. The cathode of the battery cell 102 is coupled to a port 121 of the controller 100 via a resistor 111. Within the controller 100, the inner partial path 132 is in parallel with the battery cell 102. The inner partial path 132 is coupled to an inner partial flow control switch 142. The controller 100 controls the internal partial flow control switch 142 via a control signal D2.

The anode of the battery cell 101 is coupled to a port 121 of the controller 100 via a resistor 111. The cathode of the battery cell 101 is coupled to a port 120 of the controller 100 via a resistor 100. In the controller 100, the internal partial path 131 is connected in parallel with the battery cell 101. The inner partial path 131 is connected to an inner partial flow control switch 141. The controller 100 controls the internal partial flow control switch 141 via a control signal D1. The anode of the battery cell 103 is coupled to a port 123 of the controller 100 via a resistor 113. The cathode of the battery cell 103 is coupled to a port 122 of the controller 100 via a resistor 112. In the controller 100, the internal partial path 133 is connected in parallel with the battery cell 103. The inner partial path 133 is connected to an inner partial flow control switch 143. The controller 100 controls the internal partial flow control switch 143 via a control signal D3.

When there is an imbalance between the battery cells, such as the battery core 102 When the voltage of the battery is higher than the voltage of the other cells in the battery pack, the controller 100 turns on the internal current control switch 142 to cause a shunt current (not shown) to flow through the inner partial path 132, thereby causing the battery cell 102 to The charging speed is slowed down, so that the voltage of each battery cell of the battery pack tends to be balanced.

However, this method has a disadvantage in that heat generated by the shunt current is accumulated inside the controller 100, possibly damaging the controller 100. Moreover, in order to balance the battery cells, the power of the higher voltage battery cells is consumed, and the performance of the battery pack is reduced.

Therefore, an effective control method for stacking rechargeable battery cells for power transfer and a power transfer circuit thereof are still to be developed by the industry.

The known rechargeable battery core balancing circuit has the disadvantages of generating heat and causing additional energy consumption. Therefore, it is required to be able to control the balancing effect of the rechargeable battery cells under various operating conditions, without consuming large amounts of electricity. A battery transfer circuit that charges the battery core. The method for controlling the power transfer provided by the present invention and the power transfer circuit thereof satisfy the above requirements.

According to an aspect of the present invention, a control method for stacking charge cell-to-cell power transfer includes the steps of: providing an inductor connected in parallel with a series-connected two-cell battery cell but not electrically conducting, one of which The positive electrode of the rechargeable battery cell is electrically connected to the negative electrode of another rechargeable battery cell in a direct or indirect manner to form a loop; the current flowing through the inductor is set to be cut off. Determining which of the two rechargeable battery cells has a higher charge; conducting a higher-charged rechargeable battery cell and the circuit of the inductor, so that the inductor stores power until the current flowing through the inductor reaches the cutoff amount; And conducting a lower-charge rechargeable battery cell and the circuit of the inductor, so that the inductor releases the stored power to the lower-charged rechargeable battery cell until the current flowing through the inductor changes direction.

According to the concept of the present invention, the rechargeable battery cell with a higher state of charge has a higher power.

According to another aspect of the present invention, a power transfer circuit for stacking charge between battery cells includes: an inductor connected in parallel with a series of stacked two rechargeable cells, but not electrically connected. For storing and discharging power, a positive electrode of one of the rechargeable battery cells and a negative electrode of another rechargeable battery cell are electrically connected in a direct or indirect manner to form a loop; a first switch is connected to the inductor and one of the two rechargeable battery cells. After receiving the first communication number, the circuit connecting the inductor and the charging battery core is connected; and a second switch is connected to the other of the inductor and the second charging battery core for receiving a guiding communication number and conducting the connection And a controller, comprising: a first comparator connected to a first end of the first switch and a second end for detecting across the first switch a potential difference between the two ends, and outputting a communication number to the first switch; a second comparator connected to a third end and a fourth end of the second switch for detecting a potential difference across the second switch And outputs the turn-on signal to the second switch; a first signal source for transmitting the pilot The communication number is given to the first switch; and a second signal source is used to send the communication number to the second switch.

According to the concept of the present invention, the current flowing through the inductor is preset to a cutoff amount. When the rechargeable battery core connected to the first switch has a higher power, the first signal source sends the pilot communication number to the first switch, so that the first switch Turning on the inductor and storing the power until the current flowing through the inductor reaches the cutoff amount, then the second comparator detects the potential difference across the second switch, and outputs a conduction signal to the second switch, so that the second switch is turned on and the inductor The device releases the stored charge to the lower battery charge cell until the direction of current flow through the inductor changes.

According to the concept of the present invention, the current flowing through the inductor is preset with a cutoff amount. When the rechargeable battery core connected to the second switch has a higher power, the second signal source sends the communication signal to the second switch to make the second switch. Turning on the inductor and storing the power until the current flowing through the inductor reaches the cutoff amount, then the first comparator detects the potential difference across the first switch, and outputs a conduction signal to the first switch, so that the first switch is turned on and the inductor is turned on. The device releases the stored charge to the lower battery charge cell until the direction of current flow through the inductor changes.

According to the present invention, the first switch is an N-channel metal oxide semiconductor field effect transistor or a P-channel metal oxide semiconductor field effect transistor.

According to the present invention, the second switch is an N-channel metal oxide semiconductor field effect transistor or a P-channel metal oxide semiconductor field effect transistor.

According to the concept of the present invention, the rechargeable battery cell with a higher state of charge has a higher power.

According to the present concept, when the current flowing through the inductor changes direction, the voltage difference across the switch connected to the lower battery charge cell is zero.

According to the concept of the present invention, when the difference in state of charge between the two rechargeable battery cells is less than a minimum difference value, both the first switch and the second switch are closed.

The method for controlling the power transfer and the power transfer circuit provided by the invention can use the inductor to buffer a large amount of electric energy to charge the battery core, and then fill the charged battery core with less power to achieve a rechargeable battery. The purpose of balancing between cores is not to consume unnecessary power.

D1‧‧‧ control signal

D2‧‧‧ control signal

D3‧‧‧ control signal

10‧‧‧Balance circuit

100‧‧‧ Controller

101‧‧‧ battery core

102‧‧‧ battery core

103‧‧‧ battery core

111‧‧‧resistance

112‧‧‧resistance

113‧‧‧resistance

120‧‧‧埠

121‧‧‧埠

122‧‧‧埠

123‧‧‧埠

Partial path within 131‧‧

132‧‧‧ Partial path

Partial path within 133‧‧

141‧‧‧Internal flow control switch

142‧‧‧Internal flow control switch

143‧‧‧Internal flow control switch

20‧‧‧Power Transfer Circuit

200‧‧‧Inductors

301‧‧‧First switch

3011‧‧‧ gate

3012‧‧‧First endpoint

3013‧‧‧second endpoint

302‧‧‧second switch

3021‧‧‧ gate

3022‧‧‧ third endpoint

3023‧‧‧ fourth endpoint

401‧‧‧First comparator

402‧‧‧Second comparator

403‧‧‧first signal source

404‧‧‧Second signal source

501‧‧‧First rechargeable battery core

502‧‧‧Second rechargeable battery core

503‧‧‧ Third rechargeable battery core

Figure 1 is a block diagram of a balanced circuit in front of a multi-cell.

Figure 2 is a block diagram of a power transfer circuit in accordance with the present invention.

Figure 3 depicts the stored power of an inductor in the power transfer circuit.

Figure 4 depicts the amount of charge stored in the inductor in the power transfer circuit.

Figure 5 depicts the charge transfer circuit returning to its original state.

Figure 6 is a flow chart of a method for controlling the amount of power transfer in accordance with the present invention.

Figure 7 depicts the operation of multiple sets of power transfer circuits in series.

The invention will be more specifically described by reference to the following examples.

Please refer to Figures 2 to 7. 2 is a block diagram of a power transfer circuit in accordance with the present invention, FIG. 3 depicts an inductor storage power in the power transfer circuit, and FIG. 4 depicts an amount of power released by the inductor in the power transfer circuit. Figure 5 depicts the power transfer circuit returning to the original state, Figure 6 is a flow chart of the power transfer control method in accordance with the present invention, and Figure 7 depicts the plurality of sets of power transfer circuits operating in series.

The present invention provides a power transfer circuit 20 for stacking charge cells between battery cells, comprising an inductor 200, a first switch 301, a second switch 302 and a controller 400. The inductors 200 are respectively connected in parallel with a first rechargeable battery cell 501 and a second rechargeable battery cell 502, and the two circuits formed by the first switch 301 and the second switch 302 are controlled to be non-conductive. The function of the inductor 200 is to store and release power. The first rechargeable battery core 501 and the second rechargeable battery core 502 are stacked in series with each other to provide a partial power source of a rechargeable battery pack (not shown). The negative electrode of the first rechargeable battery cell 501 is directly connected to the positive electrode of the second rechargeable battery cell 502, and the negative electrode of the second rechargeable battery cell 502 is indirectly connected to the positive electrode of the first rechargeable battery cell 501 to form a loop. The indirect method referred to herein may be through a load, such as a power supply device of an electronic device, or a charger connected to form a path. The power transfer circuit and the control method provided by the present invention can be applied regardless of whether the first rechargeable battery core 501 and the second rechargeable battery core 502 are in the case of power supply, charging, or no power in and out.

The first switch 301 is connected to the inductor 200 and the first rechargeable battery cell 501, and can be connected to the inductor 200 and the first after receiving a communication number. The circuit of the rechargeable battery cell 501. The second switch 302 is the same as the first switch 301, but the second switch 302 is connected to the inductor 200 and the second rechargeable battery cell 502, and can also be connected to the connected inductor 200 and the second rechargeable battery after receiving a communication number. The loop of the core 502. The first switch 301 is composed of a diode and a P-channel metal oxide semiconductor field effect transistor in parallel. The activation of a gate 3011 of the P-channel MOSFET is controlled by the pilot number. The communication number is a voltage value. Similarly, the second switch 302 is also composed of a diode in parallel with a P-channel metal oxide semiconductor field effect transistor. The activation of a gate 3021 of the P-channel MOSFET is also controlled by the pilot number. In practice, the P-channel metal oxide semiconductor field effect transistor can also be replaced by an N-channel metal oxide semiconductor field effect transistor, or the first switch 301 comprises a P-channel metal oxide semiconductor field effect transistor, and the second switch 302 comprises an N-channel metal oxide semiconductor field effect transistor and vice versa. For the subsequent description, in FIGS. 2 to 5 and 7, the gate 3011 of the first switch 301 and the gate 3021 of the second switch 302 are not activated by open circles, and the solid circles indicate that they have been activated.

The controller 400 includes a first comparator 401, a second comparator 402, a first signal source 403, and a second signal source 404. The first comparator 401 is coupled to a first terminal 3012 and a second terminal 3013 of the first switch 301 for detecting a potential difference across the first switch 301. The second comparator 402 is coupled to a third terminal of the second switch 302 and a third terminal 3023 of the second switch 302 for detecting a potential difference across the second switch 302. First signal source 403 or first ratio The comparator 401 can send the communication number to the gate 3011 of the first switch 301, and the second signal source 404 or the second comparator 402 can send the communication number to the gate 3021 of the second switch 302.

In order to explain the operation of the power transfer circuit 20 (the control method of the power transfer), please refer to the flowchart of FIG. The inductors 200 are respectively connected in parallel with the first rechargeable battery cells 501 and the second rechargeable battery cells 502 stacked in series, but the first switches 301 and the second switches 302 are not turned on, and are not electrically conductive. The connection arrow of the two rechargeable battery cells is connected to an electric heater (not shown) to form a loop (S01). Before the operation of the power transfer circuit 20, the current flowing through the inductor 200 is set to a cutoff amount (S02). There is no certain way to determine the cutoff amount, as long as the cutoff amount occurs, the amount of electricity stored by the inductor 200 is still within its limits.

Since the imbalance between the first rechargeable battery core 501 and the second rechargeable battery core 502 occurs, it is necessary to determine which of the first rechargeable battery core 501 and the second rechargeable battery core 502 has a higher amount of power (S03). There are many ways to determine the amount of charge in a rechargeable battery cell. A preferred example is measuring the state of charge. A rechargeable battery cell of the same specification has a higher power state with a higher power state, and a battery management system of many rechargeable battery cells can achieve the above purpose. The invention does not limit the manner in which the charge of the battery cells is determined.

If the first rechargeable battery core 501 has a higher power, the first signal source 403 sends the communication number to the first switch 301, causing the first switch 301 to be turned on and the inductor 200 to store the power. Referring to FIG. 3, a part of the charged battery core 501 is charged to the inductor 200 via the first switch 301 (for example, the arrow side). Towards). Sending the communication number until the current flowing through the inductor 200 reaches the cutoff amount (S04), then the second comparator 402 detects the potential difference between the second switch 302, and sends the communication number to the second switch 302, so that The second switch 302 is turned on and the inductor 200 releases the stored power to the second rechargeable battery core 502 having a lower power. See Figure 4, as shown by the direction of the arrow in the figure. The transmission of the communication number is continued until the direction of the current flowing through the inductor 200 is changed (see Fig. 5, S05). The direction of current flow through the inductor 200 changes, meaning that the second rechargeable battery cell 502 absorbs the discharged power (charging) and resumes the discharge state again, so the direct current power is reversed. At this time, the potential difference across the second switch 302 in the conduction loop is zero, which can be detected by the second comparator 402. On the other hand, if the second rechargeable battery core 502 has a higher power, the second switch 302 will be turned on first, and the inductor 200 first receives the power from the second rechargeable battery core 502 and then transmits it to the first rechargeable battery core 501. It should be noted that the control method of the power transfer is not necessarily achieved once, and the present invention allows the first switch 301 and the second switch 302 to be alternately alternately switched to achieve balance between the rechargeable battery cells. The best condition is to set a minimum difference value of the difference in state of charge between the two charged batteries, for example, 1%. When the difference in state of charge is less than the minimum difference, the first switch 301 and the second switch 302 are both turned off. Therefore, the balance between the rechargeable battery cells can be determined in a more economical way.

Finally, the power transfer circuit of the present invention can be alternately disposed between the series of rechargeable battery cells to achieve an equilibrium state of the entire series of rechargeable battery cells. Please refer to FIG. 7 in the original first rechargeable battery core 501 and the second rechargeable battery core. Below the 502, a third rechargeable battery cell 503 is connected in series. Another power transfer circuit 20 is connected to the second rechargeable battery cell 502 and the third rechargeable battery core 503. The two power transfer circuit 20 operates in the same manner, except that the lower power transfer circuit 20 is used to balance the second rechargeable battery core 502 and the third rechargeable battery core 503.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

20‧‧‧Power Transfer Circuit

200‧‧‧Inductors

301‧‧‧First switch

3011‧‧‧ gate

3012‧‧‧First endpoint

3013‧‧‧second endpoint

302‧‧‧second switch

3021‧‧‧ gate

3022‧‧‧ third endpoint

3023‧‧‧ fourth endpoint

401‧‧‧First comparator

402‧‧‧Second comparator

403‧‧‧first signal source

404‧‧‧Second signal source

501‧‧‧First rechargeable battery core

502‧‧‧Second rechargeable battery core

503‧‧‧ Third rechargeable battery core

Claims (10)

A control method for stacking charge cells between charged cells, comprising the steps of: providing an inductor connected in parallel with a series of stacked two rechargeable cells, but not electrically conducting, wherein one of the positive cells of the rechargeable battery cell and the other The negative electrode of the rechargeable battery cell is electrically connected in a direct or indirect manner to form a loop; the current flowing through the inductor is set to a cutoff amount; the two rechargeable battery cells are determined to have a higher power; and the rechargeable battery core having a higher power is turned on. And the circuit of the inductor, the inductor stores the amount of electricity until the current flowing through the inductor reaches the cutoff amount; and turns on the lower battery cell and the circuit of the inductor to release the inductor The amount of electricity is transferred to the lower battery cell until the current flowing through the inductor changes direction. The control method according to claim 1, wherein the rechargeable battery cell having a higher power state has a higher power. A power transfer circuit for stacking charge between battery cells, comprising: an inductor connected in parallel with a two-cell battery cell stacked in series but not electrically connected for storing and discharging power, wherein one charging Battery core The positive electrode is electrically connected to the negative electrode of another rechargeable battery cell in a direct or indirect manner to form a loop; a first switch is connected to the inductor and one of the two rechargeable battery cells for receiving a conductive communication number and conducting a connection a circuit of the inductor and the rechargeable battery core; a second switch connected to the other of the inductor and the second rechargeable battery cell for receiving a conductive communication number, and conducting a circuit connecting the inductor and the rechargeable battery core; A controller includes: a first comparator connected to a first end of the first switch and a second end for detecting a potential difference across the first switch and outputting a communication number to the first a second comparator connected to a third end and a fourth end of the second switch for detecting a potential difference across the second switch and outputting a communication number to the second switch; a signal source for transmitting the communication number to the first switch; and a second signal source for transmitting the communication number to the second switch. The power transfer circuit of claim 3, wherein the current flowing through the inductor is preset with a cutoff amount, and when the rechargeable battery core connected to the first switch has a higher power, the first signal source is sent. The communication signal is given to the first switch, so that the first switch is turned on and the inductor stores power until the current flowing through the inductor reaches the cutoff amount, and then the second comparator detects the second The potential difference between the two ends of the switch, and the output communication number to the second switch, so that the second switch is turned on and the inductor releases the stored power to the lower battery cell until the current flowing through the inductor changes direction. The power transfer circuit of claim 3, wherein the current flowing through the inductor is preset with a cutoff amount, and when the rechargeable battery core connected to the second switch has a higher power, the second signal source is sent. The first communication switch is turned on and the inductor stores the power until the current flowing through the inductor reaches the cutoff amount, and then the first comparator detects the potential difference between the first switch and outputs the communication number. The first switch is turned on, and the first switch is turned on and the inductor releases the stored power to the lower battery cell until the current flowing through the inductor changes direction. The power transfer circuit of claim 3, wherein the first switch is an N-channel metal oxide semiconductor field effect transistor or a P-channel metal oxide semiconductor field effect transistor. The power transfer circuit of claim 3, wherein the second switch is an N-channel metal oxide semiconductor field effect transistor or a P-channel metal oxide semiconductor field effect transistor. The power transfer circuit of claim 4 or 5, wherein the rechargeable battery cell having a higher power state has a higher power. The power transfer circuit of claim 4, wherein the voltage difference across the switch connected to the lower battery charge cell is zero when the current flowing through the inductor changes direction. The power transfer circuit of claim 3, wherein when the difference in state of charge between the two rechargeable cells is less than a minimum difference value, both the first switch and the second switch are turned off.