TWI497795B - Battery pulse discharge method and device - Google Patents

Description

Battery pulse wave discharge method and device

The invention relates to a battery discharge technology, in particular to a method and a device for discharging a battery in a pulse wave type.

In recent years, the popularity of various portable electronic device products and the use of electric energy as a power source for electric vehicles have significantly increased. The main power sources of these electronic products or devices are dependent on secondary batteries, so the related technologies of batteries are becoming more and more important, especially the charging and discharging of batteries is more important. In the development of battery charging technology, many advanced charging methods have been proposed. These advanced charging methods can improve battery charging performance, such as charging speed, efficiency, temperature rise and life cycle, and make battery-powered The system can achieve the ultimate performance. However, in the part of the battery discharge, the related technology is less discussed. At present, techniques for battery discharge have been proposed, namely, integer linear programming, weighted-k round-robin scheduling, energy management algorithm method, fuzzy logic control (fuzzy) Logic control) and other methods. These methods optimize the battery source, which in turn increases discharge time and life cycle. At the same time, some studies have focused on the study of pulse current (PC) discharge performance. The pulse current technology provides a pulse current instead of a constant current (CC) when the battery is being charged/discharged, thus providing a break for ion diffusion. Time, the ion distribution of the electrolyte is more uniform to improve the discharge performance, and to achieve the purpose of delaying the polarization of the battery, and can increase the efficiency and life cycle of the battery discharge. In addition, other forms of discharge waveforms, such as triangles, zigzags, and trapezoidal waveforms, have also been explored. This non-constant current discharge technique seems to be the main requirement to increase the discharge performance of the battery. Therefore, the discharge technology of non-constant current is very promising and widely used in the future. In pulse wave discharge technology, the discharge frequency is an important factor in the discharge rate and discharge capacity of the battery. However, the traditional way of finding the lowest AC resistance frequency mostly adopts the trial method or the empirical method to measure the subjectively considered minimum AC resistance frequency, and it is difficult to accurately set the lowest AC resistance frequency to an objective and accurate frequency value. The focus of the solution is to be addressed.

The main object of the present invention is to solve the above problems and to discharge a battery using a pulse voltage or a pulse current. Furthermore, the frequency of the pulse wave voltage or pulse current used is equal to the lowest AC impedance frequency of the battery.

A battery pulse discharge method that discharges a battery using a pulse voltage or a pulse current. The battery discharge method as described above, wherein the frequency of the pulse wave voltage or the pulse current is equal to the lowest AC impedance frequency of the battery or the resonance frequency of the battery or between the lowest AC impedance frequency of the battery and the resonance frequency of the battery.

A battery pulse discharge method that discharges a battery using a pulse voltage or a pulse current. In the battery pulse discharge method as described above, the frequency of the pulse wave voltage or the pulse current used is equal to the lowest AC impedance frequency of the battery.

A battery pulse wave discharge method, wherein a battery is discharged by an output pulse wave voltage, and The discharge frequency is the lowest AC impedance frequency of the battery; the minimum AC impedance frequency of the battery is judged by using a pulse wave voltage with a fixed amplitude and a different frequency to discharge the battery, and measuring the discharge current, and the frequency corresponding to the maximum discharge current is The lowest AC impedance frequency of the battery.

A battery pulse wave discharge method, wherein a battery is discharged by an output pulse current, and a discharge frequency is a minimum AC impedance frequency of the battery; the lowest AC impedance frequency of the battery is determined by using a pulse current of a fixed amplitude and a different frequency to the battery Discharge, at the same time measure the battery AC voltage, the minimum battery AC voltage corresponds to the lowest AC impedance frequency of the battery.

A battery pulse wave discharge method, the battery is discharged by pulse wave voltage or current mode, and the discharge frequency is the lowest AC impedance frequency of the battery; the minimum AC impedance frequency of the battery is judged by using the same to measure the discharge current and the battery AC voltage. The size, and then calculate the battery AC impedance at each frequency, and find out the lowest AC impedance frequency of the battery.

A battery pulse wave discharge device that discharges a battery using a pulse voltage or a pulse current, wherein a pulse wave voltage or a pulse current frequency is equal to a minimum AC impedance frequency of the battery; the minimum AC impedance frequency is associated with the battery Different and different, will also vary with battery life and usage environment. The device for determining the discharge frequency of the battery may include a current measuring device serially connected to the pulse wave discharge device and the battery; the pulse wave discharge device outputs a pulse wave voltage with a fixed amplitude and a different frequency to discharge the battery. At the same time, the current measuring device measures the magnitude of the discharging current; the frequency corresponding to the maximum discharging current is the lowest AC impedance frequency. Or the device for determining the discharge frequency of the battery may include a voltage measuring device connected to both ends of the battery; the pulse discharge device outputs a pulse current of a fixed amplitude and a different frequency to discharge the battery, and the voltage is simultaneously The measuring device measures the AC voltage of the battery; the minimum battery AC voltage The corresponding frequency is the lowest AC impedance frequency. Or the device for determining the discharge frequency of the battery may include a voltage measuring device and a current measuring device, the current device is connected in series to the pulse wave generating circuit and the battery, and the voltage measuring device is connected to both ends of the battery; the voltage The measuring device and the current measuring device measure the discharge current and the battery AC voltage, thereby calculating the AC impedance of the battery at each frequency, and thereby finding the lowest AC impedance frequency of the battery.

A minimum AC impedance frequency detecting method for a battery pulse wave discharge device, which uses a pulse wave voltage with a fixed amplitude and a different frequency to discharge the battery, and simultaneously measures the discharge current, and the frequency corresponding to the maximum discharge current is the lowest battery. AC impedance frequency.

A minimum AC impedance frequency detecting method for a battery pulse wave discharge device, which uses a pulse wave current with a fixed amplitude and a different frequency to discharge the battery, and simultaneously measures the AC voltage of the battery, and the frequency corresponding to the minimum battery AC voltage is The lowest AC impedance frequency of the battery.

A minimum AC impedance frequency detecting method for a battery pulse wave discharge device, which uses a pulse wave voltage or current with a fixed amplitude and a different frequency to discharge a battery, and simultaneously measures a discharge current and a battery AC voltage, thereby calculating each frequency. Under the battery AC impedance, and based on this to find the battery's lowest AC impedance frequency.

The main object of the present invention is to solve the method for improving the discharge performance of a battery and to provide a battery discharge method in a pulse wave type. The battery is kept at the lowest AC resistance frequency by accurately detecting the lowest AC resistance frequency when the battery is discharged. Lower discharge; by the phase detection of the battery AC voltage and current, the battery is kept discharged at the resonant frequency to increase the battery discharge time and extend the discharge speed, and improve the battery life.

10‧‧‧ Pulse discharge device

20‧‧‧Battery

110‧‧‧ Pulse Generator

30‧‧‧Voltage measuring device

120‧‧‧Controllable current device

40‧‧‧current measuring equipment

121‧‧‧Operational Amplifier

122‧‧‧Optoelectronics

123‧‧‧resistance

L _d1 ‧‧‧electrode inductance

L _d2 ‧‧‧electrode inductance

C _d1 ‧‧‧Electric double layer capacitor

C _d2 ‧‧‧Electric double layer capacitor

R _ct1 ‧‧‧Electronic transmission resistance

R _{ct2 ‧‧‧Electronic} transmission resistance

Z _w1 ‧‧‧Ion Diffusion Reactance

Z _w2 ‧‧‧Ion Diffusion Reactance

R _o ‧‧‧ohm resistance

Z _AC ‧‧‧ AC impedance value

f _r ‧‧‧resonance frequency

f _{zmin ‧‧‧lowest} AC impedance frequency

Fig. 1A is a circuit diagram of an alternating current impedance model of the battery of the present invention.

Figure 1B is an equivalent model circuit of Figure 1.

Figure 2 is a diagram of the battery impedance Bode diagram.

Figure 3 is a preferred embodiment of the invention.

Fig. 4 is a view showing a preferred embodiment of the pulse wave discharge device of the present invention.

Figure 5 is a preferred embodiment of the invention.

Figure 6 is a preferred embodiment of the invention.

Figure 7 is a preferred embodiment of the invention.

Figure 8 is a flow chart of a battery pulse discharge method of the present invention.

Figure 9 is a flow chart of a battery pulse discharge method of the present invention.

Figure 10 is a flow chart of a battery pulse discharge method of the present invention.

Referring to Figures 1 through 10, the structure of the embodiment selected for use in the present invention is for illustrative purposes only and is not limited by such structure in the patent application.

The present embodiment provides a method and apparatus for discharging a battery in a pulse wave pattern. Before describing the method and apparatus, we must first understand how to generate an optimal battery discharge frequency to improve the conventional method and find a more easily implementable method. Please refer to Figure 1A for the AC impedance model of the battery, including the electron transfer resistors R _{ct 1} and R _{ct 2} (charge transfer resistance) in series with the ion diffusion reactances Z _{w 1} and Z _{w 2} (Warburg impedance). The electric double-layer capacitors C _{d 1} and C _{d 2} (capacitance) are connected in parallel, and finally connected in series with the ohmic resistance R _o (ohmic resistance) and the electrode inductances L _{d 1} , L _{d 2} (electrode inductance), and finally connected to an ideal battery (battery) ) (Refs. 19 to 22). Converting the above battery to an equivalent model circuit is an impedance Z _AC in series with an ideal battery, as shown in Figure 1B. By analyzing the battery equivalent model through the circuit method, if a variable frequency is added to both ends of the battery, the battery impedance is also changed while changing the frequency; therefore, the frequency can be changed to obtain the lowest AC impedance Z _min on the battery. The loss of electrical energy on the AC impedance of the battery can be reduced; therefore, the amount of power loss on the battery can be controlled by the frequency of the power supply. In other words, in order to maximize the energy transfer efficiency of the battery during discharge, the minimum value of the battery AC impedance, that is, the minimum AC impedance frequency fz _min of the battery corresponding to the electrochemical reaction, must be selected. At the lowest AC resistance frequency fz _min , the lowest impedance Z _min can be obtained. Therefore, at this frequency, the battery temperature is not increased in a large amount, and the problem of the battery life can be effectively improved. As shown in Fig. 2 is the impedance of a battery Bode diagram, the battery may be apparent at the lowest frequency fz _min AC impedance do have the lowest impedance Z _min.

FIG. 3 is a schematic diagram of a battery pulse discharge method and apparatus disclosed in the present patent. In addition to the battery 20 and the load 70, a pulse discharge device 10 is connected in series with the two. A preferred embodiment of the pulse discharge device 10 is shown in FIG. 4, which is composed of at least a pulse generator 110 and a controllable current device 120. The controllable current device 120 is at least operated by an operational amplifier 121. A transistor 122 is constructed with a resistor 123. The pulse generator 110 is used to generate a pulse wave and the frequency is at the lowest AC impedance frequency fz _min .

Another embodiment is shown in FIG. 5, and a voltage measuring device 30 is used to measure the battery AC voltage as compared with FIG. If the discharge current is fixed, when the pulse discharge device 10 discharges at the pulse current of the lowest AC impedance frequency fz _min , there is a minimum battery AC voltage ( V = I ^* Z _min ), from which it can be judged whether the battery is operating. Optimal discharge frequency.

As shown in Fig. 6, in still another embodiment, a current measuring device 30 is used to measure the battery current as compared with Fig. 3. If the discharge voltage is fixed, when the pulse discharge device 10 discharges at the pulse current of the lowest AC impedance frequency fz _min , there is a maximum battery current, and accordingly, it can be determined whether the battery operates at the optimum discharge frequency.

As shown in FIG. 7, another embodiment is shown. Compared with FIG. 3, a voltage measuring device 30 and a current measuring device 40 are used to measure the battery AC voltage and current. Ohm's law The AC impedance value of the battery can be calculated to select the lowest AC resistance frequency fz _{min of the} lowest impedance Z _min of the battery 20 to charge the battery.

Figure 8 is a flow chart of a battery pulse discharge method of the present invention. At the beginning, the battery discharges a pulse current of a fixed current at a different frequency to measure the load, and simultaneously measures the AC voltage of the battery at each frequency. The frequency at which the minimum battery AC voltage is applied is the minimum AC impedance frequency fz _{min of} the battery. Finally, the system continues to discharge the load with the pulse current of the lowest AC impedance frequency fz _min of the battery.

FIG. 9 is a flow chart of a battery pulse discharge method according to the present patent. At the beginning, the battery discharges the pulse voltage with a fixed voltage of different frequencies to the load, and simultaneously measures the battery current at each frequency. The frequency at which the maximum battery current is applied is the lowest AC impedance frequency fz _{min of} the battery. Finally, the system continues to discharge the load with the pulse current of the lowest AC impedance frequency fz _min of the battery.

Figure 10 is a flow chart of a battery pulse discharge method of the present invention. At the beginning, the battery discharges the load with pulse waves of different frequencies, and simultaneously measures the AC voltage and current of the battery at each frequency, and calculates each according to this. Battery AC impedance at the frequency point. Finally, the system continues to discharge the load with the pulse current of the lowest AC impedance frequency fz _min of the battery.

To verify the feasibility of this patent, three commercial batteries A, B, and C (Sanyo 18650 1500 mAH lithium ion battery) were used for the experiment. The average of the experimental results for the three batteries is listed in the table below.

It can be seen from the table that the pulse current discharge of the lithium ion battery using the lowest AC impedance frequency fz _min of the battery can improve the discharge efficiency of the battery and also reduce the temperature rise of the battery.

It is not difficult to find out from the above description that the advantage of the present invention is that the battery can obtain a longer discharge time by the lowest AC resistance frequency, and the electrolyte of the battery can be balancedly distributed to improve the uniformity of the electrolyte reaction and effectively increase the discharge. Time And reduce the aging of the electrode, thereby improving battery life.

10‧‧‧ Pulse discharge device

110‧‧‧ Pulse Generator

120‧‧‧Controllable current device

121‧‧‧Operational Amplifier

122‧‧‧Optoelectronics

123‧‧‧resistance

20‧‧‧Battery

70‧‧‧ load

Claims (4)

A battery pulse wave discharge method, wherein a battery is discharged by an output pulse wave voltage, and a discharge frequency is a minimum AC impedance frequency of the battery; the minimum AC impedance frequency of the battery is determined by using a pulse wave voltage of a fixed amplitude and a different frequency to discharge the battery At the same time, the discharge current is measured, and the frequency corresponding to the maximum discharge current is the lowest AC impedance frequency of the battery. A battery pulse wave discharge method, wherein a battery is discharged by an output pulse current, and a discharge frequency is a minimum AC impedance frequency of the battery; the lowest AC impedance frequency of the battery is determined by using a pulse current of a fixed amplitude and a different frequency to the battery Discharge, at the same time measure the battery AC voltage, the minimum battery AC voltage corresponds to the lowest AC impedance frequency of the battery. A battery pulse wave discharge method, the battery is discharged by pulse wave voltage or current mode, and the discharge frequency is the lowest AC impedance frequency of the battery; the minimum AC impedance frequency of the battery is judged by using the same to measure the discharge current and the battery AC voltage. The size, and then calculate the battery AC impedance at each frequency, and find out the lowest AC impedance frequency of the battery. A battery pulse wave discharge device that discharges a battery using a pulse voltage or a pulse current, wherein a pulse wave voltage or a pulse current frequency is equal to a minimum AC impedance frequency of the battery; the minimum AC impedance frequency is associated with the battery Different from the battery life and the use environment change; the battery discharge frequency judging device may include a current measuring device, the current measuring device is connected in series with the pulse wave discharging device and the battery; The pulse wave discharge device outputs a pulse wave voltage with a fixed amplitude and a different frequency to discharge the battery, and the current measuring device measures the discharge current magnitude; the frequency corresponding to the maximum discharge current is the lowest AC impedance frequency; or the discharge frequency of the battery The determining device may include a voltage measuring device, and the voltage measuring device And connected to the two ends of the battery; the pulse discharge device outputs a pulse wave current with a fixed amplitude and different frequency to discharge the battery, and the voltage measuring device measures the AC voltage of the battery; the frequency corresponding to the minimum battery AC voltage is the lowest The AC impedance frequency; or the battery discharge frequency judging device may include a voltage measuring device and a current measuring device, the current device is connected in series to the pulse wave generating circuit and the battery, and the voltage measuring device is connected to the battery The voltage measuring device and the current measuring device measure the discharging current and the battery AC voltage, thereby calculating the AC impedance of the battery at each frequency, and thereby finding the lowest AC impedance frequency of the battery.