CN114336863B - Capacitive inductance solving circuit of battery module short-plate battery monomer - Google Patents

Abstract

The invention discloses a capacitance-inductance solving circuit of a battery module short-plate battery cell, which comprises a battery module, a capacitance-inductance balancing module and a unidirectional MOS tube switch assembly. The beneficial effects of the invention are as follows: the energy of each battery cell in the whole series module can be independently controlled, so that the consistency of the battery cells of the series battery module in the working state is ensured; by adopting a standby battery monomer mode, each battery monomer can be basically filled and discharged with energy, so that the energy of the battery module is maximally utilized; any two battery monomers of the battery module can directly transfer electric energy through the capacitance-inductance equalization module, discharging of the battery monomer with high voltage and charging of the battery monomer with low voltage are simultaneously carried out, energy flows bidirectionally, and energy transfer speed is high; the use of the whole battery module can not be influenced by the appearance of the short-plate battery monomer in the battery module, and the service life of the battery module is greatly prolonged.

Description

Capacitive inductance solving circuit of battery module short-plate battery monomer

Technical Field

The invention relates to a capacitance-inductance solution circuit, in particular to a capacitance-inductance solution circuit of a battery module short-plate battery cell, and belongs to the technical field of battery management.

Background

The working scheme of the existing battery module is that the whole series battery module is charged and discharged, namely, in the charging process, as long as any one of the battery monomers reaches a charging voltage cut-off threshold value, the whole battery module stops charging; in the discharging process, as long as any one of the single batteries reaches the discharge voltage cut-off threshold, the whole battery module stops discharging. In this working process, it can be seen that a certain short-plate battery cell in the battery module, which reaches the cut-off threshold of the charge-discharge voltage first, can severely restrict the charge-discharge capability of the whole battery module.

The service life of the battery module is seriously affected by the inconsistency of the batteries, and the battery module is obviously inferior to the single battery performance in the aspects of cycle life, capacity utilization rate and the like according to the wooden barrel effect. Along with the recycling of the battery module, the inconsistency of the battery cells is aggravated, and the appearance of the short-plate battery cells is further promoted, so that the performance of the battery module is greatly attenuated, and in extreme cases, even serious accidents such as combustion, explosion and the like are possible.

At present, a traditional battery management technology solves the problem of short-circuit effect of a battery module by adopting battery equalization. The battery balance management means that the capacity between the battery cells reaches approximately uniform level by directly consuming generated heat through a bypass resistor or transferring the electric quantity of the phase difference between the battery cells by using an energy storage element. The conversion efficiency of the battery module can be improved, the service life of the battery module is prolonged, the available capacity of the battery module is improved, and the battery module can be prevented from being in an unsafe state to a certain extent. However, the battery equalizer can only solve the problem that the battery capacity of each battery cell is inconsistent after the battery module is used for a long time, that is, the battery module with the short-plate battery cell can only be independently equalized, so that the performances of all battery cells in the battery module are consistent, and the short-plate effect is eliminated.

Therefore, the conventional battery management solution cannot solve the problem that the battery module has the short-plate battery cell during actual use, so that the performance of the battery module cannot be fully exerted.

Disclosure of Invention

The invention aims to solve the problem and provide a capacitance-inductance solving circuit of a battery module short-plate battery cell, which can basically enable each battery cell to charge and discharge to a target cut-off voltage threshold value, thereby achieving the maximum utilization of the performance of the battery module.

The invention realizes the above purpose through the following technical scheme: the capacitive and inductive solving circuit for short-plate battery cell of battery module comprises

The battery module is formed by connecting a plurality of battery monomers in series;

the battery module comprises a capacitor-inductor balancing module, wherein all battery cells of the battery modules which are connected in series are shared by the capacitor-inductor balancing module, the capacitor-inductor balancing module comprises a plurality of energy storage inductors and an energy storage capacitor, and each battery cell is connected with the capacitor-inductor balancing module in parallel;

the unidirectional MOS tube switch assembly consists of a plurality of unidirectional MOS tube switches, controls any combination and on-off of the unidirectional MOS tube switches and overall working logic among the unidirectional MOS tube switches through the control circuit, can receive and monitor the working state information of the whole circuit integration, and processes and judges the received information.

As still further aspects of the invention: the unidirectional MOS tube switch assembly comprises a unidirectional MOS tube switch III and a unidirectional MOS tube switch IV which are used for controlling the charge and discharge of each battery cell, and the unidirectional MOS tube switch III and the unidirectional MOS tube switch IV are connected in parallel.

As still further aspects of the invention: the unidirectional MOS tube switch assembly comprises a unidirectional MOS tube switch five and a unidirectional MOS tube switch six which are used for controlling the bypass function of each battery cell, and the unidirectional MOS tube switch five and the unidirectional MOS tube switch six are connected in parallel.

As still further aspects of the invention: each energy storage inductor is connected with a unidirectional MOS tube switch nine in series, each energy storage inductor is connected with a unidirectional MOS tube switch ten which is arranged in parallel, and the two unidirectional MOS tube switches ten are designed back to back.

As still further aspects of the invention: the positive electrode circuit on the right side of the capacitance-inductance equalization module is connected with a unidirectional MOS tube switch I and a unidirectional MOS tube switch II which respectively control the working states of the positive electrode circuit of each battery cell and the capacitance-inductance equalization module, and the unidirectional MOS tube switch I and the unidirectional MOS tube switch II are connected in parallel.

As still further aspects of the invention: the positive electrode circuit on the left side of the capacitance-inductance equalization module is connected with a unidirectional MOS tube switch seven and a unidirectional MOS tube switch eight which respectively control the working states of the negative electrode circuit of each battery cell and the capacitance-inductance equalization module, and the unidirectional MOS tube switch seven and the unidirectional MOS tube switch F are connected in parallel.

A circuit method for solving capacitance and inductance of battery module short-plate battery cell comprises the following steps

Step one, adopting n+1 battery cells to connect in series to form a battery module, wherein the actual battery module adopts n battery cells and 1 standby battery cell to be put into operation;

and step two, performing rotation work between the standby battery monomer and other n battery monomers of the battery module.

The beneficial effects of the invention are as follows:

1. accessible one-way MOS pipe switch W₁ ～W_n+1 、X₁ ～X_n+1 、Y₁ ～Y_n+1 、V₁ ～V_n+1 Each battery monomer in the whole serial module is independently controlled in working state;

2. the energy of each battery cell in the whole series module can be independently controlled, so that the consistency of the battery cells of the series battery module in a working state is ensured, and the consistency requirement of the battery cells in the assembly process of the battery module is greatly reduced;

3. by adopting a standby battery monomer mode, each battery monomer can be basically filled and discharged with energy, so that the energy of the battery module is maximally utilized;

4. any two battery monomers of the battery module can directly transfer electric energy through the capacitance-inductance equalization module, discharging of the battery monomer with high voltage and charging of the battery monomer with low voltage are simultaneously carried out, energy flows bidirectionally, and energy transfer speed is high;

5. the invention can not influence the use of the whole battery module due to the appearance of the short-plate battery cells in the battery module, and greatly prolongs the service life of the battery module.

Drawings

FIG. 1 is a circuit diagram of a capacitive inductance solution circuit of a battery module short-plate battery cell of the invention;

FIG. 2 is a circuit diagram of a capacitive-inductive equalization module according to the present invention;

FIG. 3 is a schematic diagram of a battery cell B according to the present invention₁ A current diagram for charging the energy storage capacitor C;

FIG. 4 is a current pattern of the inductive energy storage and capacitive discharge of the present invention;

FIG. 5 is a current pattern of capacitive storage and inductive discharge in accordance with the present invention;

FIG. 6 is a schematic diagram of a battery cell B according to the present invention_n+1 A current pattern for charging the battery module by the bypass function of (a);

FIG. 7 shows a battery cell B according to the present invention_n A current pattern of the external discharge of the bypass function battery module;

fig. 8 is an external discharge and backup battery cell B of the battery module according to the present invention₁ Current patterns for delivering electrical energy.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Example 1

As shown in fig. 1 to 2, a capacitive-inductive solving circuit of a battery module short-plate battery cell comprises

The battery module is formed by connecting a plurality of battery monomers B in series;

the battery module comprises a capacitor-inductor balancing module, wherein all battery cells B of the whole battery module which are connected in series share one capacitor-inductor balancing module, the capacitor-inductor balancing module comprises a plurality of energy storage inductors L and an energy storage capacitor C, and each battery cell B is connected with the capacitor-inductor balancing module in parallel;

the unidirectional MOS tube switch assembly consists of a plurality of unidirectional MOS tube switches, controls any combination and on-off of the unidirectional MOS tube switches and overall working logic among the unidirectional MOS tube switches through the control circuit, can receive and monitor the working state information of the whole circuit integration, and processes and judges the received information.

In the embodiment of the invention, the unidirectional MOS tube switch assembly comprises unidirectional MOS tube switches three W and unidirectional MOS tube switches four X for controlling charge and discharge of each battery cell B, and the unidirectional MOS tube switches three W and the unidirectional MOS tube switches four X are connected in parallel.

In the embodiment of the invention, the unidirectional MOS tube switch assembly comprises unidirectional MOS tube switches five Y and unidirectional MOS tube switches six V for controlling the bypass function of each battery cell B, and the unidirectional MOS tube switches five Y and the unidirectional MOS tube switches six V are connected in parallel.

In the embodiment of the invention, each energy storage inductor L is connected with a unidirectional MOS tube switch nine S in series, each energy storage inductor L is connected with a unidirectional MOS tube switch ten Q which is arranged in parallel, and the two unidirectional MOS tube switches ten Q are designed back to back.

In the embodiment of the invention, a positive electrode line on the right side of the capacitance-inductance equalization module is connected with a unidirectional MOS tube switch I J and a unidirectional MOS tube switch II K which respectively control the working states of the positive electrode circuit of each battery cell B and the capacitance-inductance equalization module, and the unidirectional MOS tube switch I J and the unidirectional MOS tube switch II K are connected in parallel.

In the embodiment of the invention, a positive electrode line on the left side of the capacitance-inductance equalization module is connected with a unidirectional MOS tube switch seven E and a unidirectional MOS tube switch eight F which respectively control the working states of a negative electrode circuit of each battery cell B and the capacitance-inductance equalization module, and the unidirectional MOS tube switch seven E and the unidirectional MOS tube switch eight F are connected in parallel.

Example two

As shown in fig. 3 to 8, a circuit for solving the capacitance and inductance of a short-plate battery cell of a battery module will now be described in detail with reference to the working logic process of the whole battery module. The specific implementation steps are as follows:

in the first case, the capacitance and inductance of the battery module are balanced.

Capacitance-inductance equalization module and each battery cell B of the whole series battery module₁ ～B_n+1 And each battery cell in the whole series battery module shares the same capacitance-inductance equalization module for a parallel circuit. Any two battery monomers in the battery module can be directly transferred through the intermediation of the capacitance-inductance equalization moduleThe energy is equalized.

In order to improve the equalization efficiency, energy transfer equalization between the highest voltage battery cell and the lowest voltage battery cell is preferentially performed. The specific equalization steps are as follows:

suppose that battery cell B in battery module₁ Voltage value of (a) is higher than that of battery cell B_n The voltage values of the battery module are high, and the battery module is respectively the highest voltage battery cell and the lowest voltage battery cell at the moment, and the two battery cells can be balanced preferentially at the moment.

Step 1, enabling a unidirectional MOS tube switch X through a control circuit₁ 、F₁ 、S₂ 、Q₃ Conduct and let battery cell B₁ Positive electrode, energy storage inductance L₁ Energy storage capacitor C and energy storage inductor L₄ Battery cell B_n The negative electrode forms a current path, so that one end of the energy storage capacitor C is a battery cell B₁ The other end of the positive electrode is a battery cell B_n The negative electrode causes the voltage difference between the two ends of the energy storage capacitor C to exist in the battery cell B₁ Positive electrode and battery cell B_n And a current I for charging the energy storage capacitor C is formed between the cathodes, and finally the energy storage capacitor C is fully charged. Such battery cell B₁ And a part of the electric energy is transferred to the storage capacitor C. In the process, only the energy storage capacitor C stores the electric energy, and the energy storage inductor L₁ And L₄ No electrical energy is stored.

Battery cell B₁ The current diagram for charging the storage capacitor C is shown in fig. 3.

Step 2, after the electric energy transfer in the step 1, the energy storage capacitor C is fully charged, and the unidirectional MOS tube switch X is enabled by the control circuit₁ 、F₁ 、S₂ Keep on, Q₃ Closing, S₄ 、S₅ 、Q₄ 、K_n 、W_n All are conducted, at this time, battery cell B₁ Current I flowing out₁ Inductance L is made₁ Storing energy; capacitor C discharge current I₂ Inductance L is made₄ Energy storage and simultaneous supply to cell B_n And (5) transferring the electric quantity by charging. Battery cell B₁ Is formed by the discharge of (a) and the battery cell B_n Is filled with (a)The electricity is performed simultaneously, and the energy flows bidirectionally.

The current patterns of the inductive storage and capacitive discharge are shown in fig. 4.

Step 3, following the step 2 battery cell B above₁ To inductance L₁ Charging current I is obtained by simultaneously charging energy storage and discharging capacitor C₁ And discharge current I₂ Will gradually increase to peak current, at which point X₁ 、F₁ 、S₂ Switch S of one-way MOS tube is kept on and closed₅ Turn on S₇ ，S₄ 、Q₄ 、K_n 、W_n The on state is maintained. Battery cell B at this time₁ And inductance L₁ The inductive electromotive force is added to charge the capacitor C, and the charging current I₁ The capacitor C stores energy; inductance L₄ Discharging the energy stored in the step 2, and discharging the current I₂ To battery cell B_n And (5) transferring the electric quantity by charging. Battery cell B₁ Is formed by the discharge of (a) and the battery cell B_n Simultaneously, energy flows in both directions.

The current patterns of capacitive storage and inductive discharge are shown in fig. 5.

Step 4, following the above step 3, the battery cell B₁ And inductance L₁ Inductive electromotive force is added to charge capacitor C and inductance L₄ Simultaneous discharge and charging current I₁ And discharge current I₂ The peak current is gradually reduced to zero, the capacitor C stores energy, and the unidirectional MOS transistor switch S is closed at the moment₇ 、S₂ 、S₄ 、Q₄ 、K_n 、W_n 。

The circuit state at the end of the 4 th step is the same as the circuit state at the end of the 1 st step, and if the energy transfer is to be continued, the steps of 2, 3 and 4 can be sequentially performed.

Through the electric energy transfer from the step 1 to the step 4, the battery cell B can be obtained₁ Battery cell B_n Much of the electrical energy is transferred to cell B_n Thereby finally making battery cell B₁ And battery cell B_n The stored electric energy is consistent, and the voltages are substantially equal.

Similarly, the electric energy transfer between any two battery cells in the battery module can be completed through similar steps from the steps 1 to 4, so that the electric energy consistency of all the battery cells in the battery module can be finally achieved.

In the second case, the battery module is charged.

Assuming that all the battery cells in the battery module are charged initially, as the battery module is charged, one of the battery cells must first reach the cut-off charging voltage value, if the condition is left according to the existing circuit method, all other battery cells in the battery module are not fully charged, and the usable capacitance of the battery module is greatly reduced, and the coping strategy of the circuit scheme of the invention under the condition has two:

1) Policy one assumes battery cell B in battery module_n+1 The charge cut-off threshold is reached first, and at this time, battery cell B is adopted_n+1 By-pass function of (a) to let battery cell B_n+1 The charging is stopped, and the other battery cells in the battery module continue to be charged.

Control circuit makes and battery cell B_n+1 Related unidirectional MOS transistor switch Y_n+1 Turned on and W_n+1 、X_n+1 、V_n+1 Closing, charging current i passes through unidirectional MOS tube switch Y_n+1 Bypass cell B_n+1 The current bypasses the battery module to continue to charge the battery module.

Battery cell B_n+1 The direction of the current for charging the battery module by the bypass function of (a) is shown in fig. 6.

2) And in the second strategy, in the process of charging the battery module, the voltage value of each battery cell in the battery module is monitored in real time through a control circuit, and at any moment, the process of transferring electric energy from the highest-voltage battery cell in the battery module to the lowest-voltage battery cell through the capacitance-inductance equalization module is performed. The strategy charging method can improve the rate of charging the battery module.

Through the cooperation of the strategy one and the strategy two, each battery cell in the battery module can be charged to a charge cut-off threshold value, so that the maximum chargeable capacity of the battery module can be realized.

And in the third case, discharging the battery module.

Assuming that all the battery cells in the battery module are discharged, as the battery module is discharged, one of the battery cells must first reach a cut-off discharge voltage value, if the condition occurs according to the existing circuit method, all other battery cells in the battery module are not discharged to a discharge cut-off threshold value, and the dischargeable electric quantity of the battery module is greatly reduced, and the coping strategy of the circuit scheme of the invention under the condition has two:

1) Policy one assumes battery cell B in battery module_n The discharge cut-off threshold is reached first, at this time, battery cell B is adopted_n By-pass function of (a) to let battery cell B_n The discharge is stopped and the other battery cells in the battery module continue to discharge.

Control circuit makes and battery cell B_n Related unidirectional MOS transistor switch V_n Turned on and W_n 、X_n 、Y_n Closing, discharging current i passes through unidirectional MOS tube switch V_n Bypass cell B_n The current bypasses the battery module and the battery module continues to discharge outwards.

Battery cell B_n The current direction of the external discharge of the bypass function battery module is shown in fig. 7.

2) And in the second strategy, in the process of discharging the battery module, the voltage value of each battery cell in the battery module is monitored in real time through a control circuit, and at any moment, the process of transferring electric energy from the highest-voltage battery cell in the battery module to the lowest-voltage battery cell through the capacitance-inductance equalization module is performed. The strategy discharging method can furthest delay the arrival time of the short-plate battery monomer in the discharging process.

Through the cooperation of the strategy one and the strategy two, each battery cell in the battery module can be discharged to a discharge cut-off threshold value, so that the maximum discharge capacity utilization of the battery module can be realized.

In the fourth case, a certain battery cell is used as a backup.

Assume that n+1 battery cells B in the scheme of the invention₁ ～B_n+1 The battery module formed by connecting n battery cells in series is only needed in the actual use process, so that an extra battery cell can be used as a backup battery cell which can be flexibly used, and the specific use strategies are as follows:

1) In the charging process of the battery module, a bypass function of the battery cells is adopted, so that the serial number of the battery cells of the battery module which is directly connected into the charging circuit is always n at any moment, the redundant battery cells and the battery cells which are being charged in the battery module are subjected to balanced energy transfer in real time, and each small period of time is passed, the redundant battery cells are connected into the battery module for charging, and the battery cells with the highest voltage value in the battery module which is being charged are naturally required to be replaced, so that the charging of the battery cells is alternated, and n+1 battery cells can be charged to a charging cut-off threshold value, so that the charging capacity of each battery cell is fully utilized.

2) In the discharging process of the battery module, a bypass function of the battery cells is adopted, so that the serial number of the battery cells directly connected to the discharging circuit of the battery module is always n at any moment, the redundant battery cells and the discharging battery cells in the battery module are subjected to balanced energy transfer in real time, and each small period of time is passed, the redundant battery cells are connected to the battery module for discharging, and the battery cells with the lowest voltage value in the discharging battery module are required to be replaced, so that the discharging of the battery cells is rotated, n+1 battery cells can be discharged to a discharging cut-off threshold value, and the discharging capacity of each battery cell is fully utilized.

3) With the use of the battery module, when one of the n+1 battery cells becomes a short-plate battery cell, the short-plate battery cell can still be used as a backup battery cell by adopting the method.

The specific usage scheme of the backup battery cell is exemplified as follows:

suppose that the n+1 battery cells B₁ ～B_n+1 The series-connected battery modules are fully charged, and the battery modules formed by connecting n battery cells in series need to be used for discharging outwards, and the short-plate battery cells in n+1 battery cells are assumed to be sequenced as B in sequence₁ 、B_n+1 In this case, B is used₂ ～B_n+1 The battery modules formed by serial connection discharge outwards, and the battery unit B₁ As a battery cell. Due to B_n+1 In order to provide a short-plate battery cell during the external discharge of the battery module, a spare battery cell B is needed from the beginning of the discharge of the battery module₁ The electric energy of the battery module is continuously transferred to the short-plate battery cell B of the battery module through the capacitance-inductance equalization module_n+1 。

When the battery module discharges outwards, the spare battery monomer B₁ Operate in the discharge bypass function mode and supply short-circuit cell B_n+1 The power is transferred and the current pattern of the working circuit is shown in figure 8.

As shown in fig. 8, the working current of the battery module for external discharge is I₁ Standby battery cell B₁ The charging current of the discharging capacitor inductance equalization module is I₂ The capacitance-inductance equalization module discharges to the short-circuit battery cell B_n+1 The charging current is I₃ 。

With the discharge of the battery module and the standby battery cell B₁ Discharging short-plate battery cell B_n+1 Replenishing electric energy, and when a certain moment comes, short-plate battery cell B_n+1 May no longer be a short-plate cell, at which point battery cell B is ready₁ The supply of the battery cell B is stopped_n+1 Replenishing the electrical energy, but instead replenishing other cells considered as short plates. The cycle is repeated until the n+1 cells are depleted of stored electrical energy. Such an operation mode can exert the functions of the battery module to the greatest extent.

Working principle: n+1 battery cells are connected in series to form a battery module, and n battery cells and 1 standby battery cell are put into the actual battery module during operation; and the spare battery monomer and the other n battery monomers of the battery module are subjected to rotation work.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.

Claims (2)

1. A capacitance-inductance solving circuit of a battery module short-plate battery cell is characterized in that: the battery module is formed by connecting a plurality of battery cells (B) in series;

the battery module comprises a capacitor-inductor balancing module, wherein all battery cells (B) of the whole battery modules which are connected in series share one capacitor-inductor balancing module, the capacitor-inductor balancing module comprises a plurality of energy storage inductors (L) and an energy storage capacitor (C), and each battery cell (B) is connected with the capacitor-inductor balancing module in parallel;

the unidirectional MOS tube switch assembly consists of a plurality of unidirectional MOS tube switches, controls any combination and on-off of all the unidirectional MOS tube switches and overall working logic among the unidirectional MOS tube switches through the control circuit, can receive and monitor the working state information of the whole circuit integration, and processes and judges the received information;

the unidirectional MOS tube switch assembly comprises unidirectional MOS tube switches three (W) and unidirectional MOS tube switches four (X) which are used for controlling the charge and discharge of each battery cell (B), and the unidirectional MOS tube switches three (W) and the unidirectional MOS tube switches four (X) are connected in parallel;

the unidirectional MOS tube switch assembly comprises unidirectional MOS tube switches five (Y) and unidirectional MOS tube switches six (V) for controlling the bypass function of each battery cell (B), and the unidirectional MOS tube switches five (Y) and the unidirectional MOS tube switches six (V) are connected in parallel;

the positive electrode circuit on the right side of the capacitance-inductance equalization module is connected with a one-way MOS tube switch I (J) and a one-way MOS tube switch II (K) which respectively control the working states of the positive electrode circuit of each battery cell (B) and the capacitance-inductance equalization module, and the one-way MOS tube switch I (J) and the one-way MOS tube switch II (K) are connected in parallel;

the positive electrode circuit on the left side of the capacitance-inductance equalization module is connected with a unidirectional MOS tube switch seven (E) and a unidirectional MOS tube switch eight (F) which respectively control the working states of the negative electrode circuit of each battery cell (B) and the capacitance-inductance equalization module, and the unidirectional MOS tube switch seven (E) and the unidirectional MOS tube switch eight (F) are connected in parallel.

2. The capacitive-inductive solving circuit of a battery module short-plate battery cell according to claim 1, wherein: every energy storage inductance (L) all establishes ties has a one-way MOS pipe switch nine (S), and every all be connected with on the energy storage inductance (L) and be the ten (Q) of one-way MOS pipe switch that the parallel form set up, and two one-way MOS pipe switches ten (Q) are back-to-back design.