Dual-power-supply power battery system

Abstract

The utility model discloses a dual-power-supply power battery system. The dual-power-supply power battery system comprises a battery unit for providing electric energy, a control unit for controlling the flow direction of current and a protection unit for protecting the battery system, the battery unit comprises a first power battery and a second power battery; the control unit comprises a plurality of relays; the protection unit comprises a plurality of diodes. According to the utility model, the adhesion of the relay can be eliminated and the service life of the relay can be prolonged under the condition of switching among various charging and discharging modes.

Description

Technical Field

[0001] The utility model relates to the field of power batteries, and in particular to a dual-power supply power battery system. Background Art

[0002] At present, the existing power battery technology solution can make the power battery system enter the series mode and parallel mode through relay connection, and prevent the power battery with higher voltage from charging the power battery with lower voltage with high current through the reverse cutoff characteristics of the diode, so as to realize parallel charging and discharging when the voltage of the first power battery is higher than that of the second power battery;

[0003] However, in the above technical solution, when the voltage of the second power battery is higher, the two branches connected in parallel cannot play a protective role due to the forward conduction characteristics of the diode, and directly closing the electromagnetic relay may generate an impact current; and when the voltage of the first power battery is higher than that of the second power battery during driving, the power battery discharge polarization will lead to inaccurate voltage judgment through the diode discharge state, and the closing of the electromagnetic relay will also have a large impact current, which may cause the relay to stick.

[0004] Therefore, in order to solve the problem of relay adhesion in a dual-power battery system that can switch between series and parallel, a new dual-power battery system is urgently needed that can eliminate relay adhesion and extend the service life of the relay when switching between various charging and discharging modes. Utility Model Content

[0005] In view of this, the purpose of the utility model is to overcome the defects in the prior art and provide a dual-power power battery system that can eliminate the adhesion of the relay and extend the service life of the relay when switching between various charging and discharging modes.

[0006] The dual-power battery system of the utility model comprises a battery unit for providing electric energy, a control unit for controlling the flow of current, and a protection unit for protecting the battery system;

[0007] The battery unit includes a first power battery and a second power battery;

[0008] The control unit includes a number of relays;

[0009] The protection unit includes a plurality of diodes.

[0010] Further, the charging positive interface DC+ is connected to the first end of the electromagnetic relay K3, the second end of the electromagnetic relay K3 is connected to the first end of the electromagnetic relay K8, the second end of the electromagnetic relay K8 is connected to the first end of the electromagnetic relay K1, and the second end of the electromagnetic relay K1 is connected to the discharging positive interface HV+;

[0011] The first end of the solid-state relay S1 is connected to the common connection point of the electromagnetic relay K3 and the electromagnetic relay K8, the second end of the solid-state relay S1 is connected to the common connection point of the electromagnetic relay K8 and the electromagnetic relay K1, the first end of the pre-charge relay K2 is connected to the common connection point of the electromagnetic relay K8 and the electromagnetic relay K1, and the second end of the pre-charge relay K2 is connected to the common connection point of the electromagnetic relay K1 and the discharge positive interface HV+ through the resistor R;

[0012] The positive electrode of the first power battery is connected to the common connection point of the electromagnetic relay K3 and the electromagnetic relay K8, the negative electrode of the first power battery is connected to the first end of the electromagnetic relay K7, and the second end of the electromagnetic relay K7 is connected to the discharge negative interface HV- through the electromagnetic relay K4;

[0013] The first end of the electromagnetic relay K6 is connected to the common connection point of the first power battery and the electromagnetic relay K7, and the second end of the electromagnetic relay K6 is connected to the common connection point of the electromagnetic relay K1 through the electromagnetic relay K5 and the electromagnetic relay K8;

[0014] The anode of the diode D1 is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, the cathode of the diode D1 is connected to the common connection point of the electromagnetic relay K5 and the electromagnetic relay K1, the first end of the solid-state relay S2 is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, and the second end of the solid-state relay S2 is connected to the common connection point of the electromagnetic relay K5 and the electromagnetic relay K1;

[0015] The positive pole of the second power battery is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, the negative pole of the second power battery is connected to the negative charging interface DC-, and the common connection point of the second power battery and the negative charging interface DC- is connected to the common connection point of the electromagnetic relay K7 and the electromagnetic relay K4.

[0016] Furthermore, the diode D1 is a power diode.

[0017] Furthermore, both the solid-state relay S1 and the solid-state relay S2 can be replaced by electromagnetic relays.

[0018] The beneficial effects of the utility model are as follows: a dual-power power battery system disclosed by the utility model, through the impact resistance characteristics of the solid-state relay, closes the solid-state relay during driving to achieve a preliminary parallel discharge mode, which can meet the demand for switching to the parallel discharge mode during high-speed driving, and when the vehicle brakes or coasts, it can switch to the electromagnetic relay to meet the discharge needs of extreme working conditions such as sudden acceleration; by preferentially closing the solid-state relay to meet the basic driving discharge needs, after the voltages of the two branches where the dual power sources are located are balanced (usually completed within 30 seconds), it switches to the electromagnetic relay, which solves the risk of relay adhesion, and at the same time can meet the preset conditions to switch from the partial discharge mode to the parallel discharge mode, which is more in line with actual needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 This is a schematic diagram of the circuit structure of a battery system according to an embodiment of the utility model;

[0021] Figure 2 This is a schematic diagram of the BAT1 partial discharge mode circuit structure of an embodiment of the utility model;

[0022] Figure 3 This is a schematic diagram of the BAT2 discharge mode circuit structure of an embodiment of the utility model;

[0023] Figure 4 This is a schematic diagram of the circuit structure of a parallel discharge mode of an embodiment of the utility model;

[0024] Figure 5 This is a schematic diagram of the BAT1 charging mode circuit structure of an embodiment of the utility model;

[0025] Figure 6 This is a schematic diagram of the BAT2 charging mode circuit structure of an embodiment of the utility model;

[0026] Figure 7 This is a schematic diagram of the circuit structure of a parallel charging mode of an embodiment of the utility model;

[0027] Figure 8 This is a schematic diagram of a series charging mode circuit structure of an embodiment of the utility model. DETAILED DESCRIPTION

[0028] The utility model is further described below in conjunction with the accompanying drawings of the specification, as shown in the figure:

[0029] The dual-power battery system of the utility model comprises a battery unit for providing electric energy, a control unit for controlling the flow of current, and a protection unit for protecting the battery system;

[0030] The battery unit includes a first power battery BAT1 and a second power battery BAT2;

[0031] The control unit includes electromagnetic relays K1, K3, K4, K5, K6, K7, K8, pre-charge relay K2 and solid-state relays S1, S2;

[0032] The protection unit includes a diode D1.

[0033] The battery system of the utility model can realize several charging and discharging modes including BAT1 partial discharge mode, BAT2 discharge mode, parallel discharge mode and BAT1 charging mode, BAT2 charging mode, parallel charging mode and series charging mode, and can switch between various charging and discharging modes without affecting the life of the relay.

[0034] By switching modes, when the vehicle switches to the series mode when charging at a super charging station, the charging voltage of the battery system can be increased from the 400V platform to the 800V platform, which can achieve high-power charging. At the same time, the battery system's power supply voltage for the entire vehicle remains at the 400V platform, and the vehicle's motor, electronic control, air conditioning and other components can still use lower-priced 400V voltage platform products.

[0035] In this embodiment, Figure 1 As shown, the charging positive interface DC+ is connected to the first end of the electromagnetic relay K3, the second end of the electromagnetic relay K3 is connected to the first end of the electromagnetic relay K8, the second end of the electromagnetic relay K8 is connected to the first end of the electromagnetic relay K1, and the second end of the electromagnetic relay K1 is connected to the discharge positive interface HV+;

[0036] The first end of the solid-state relay S1 is connected to the common connection point of the electromagnetic relay K3 and the electromagnetic relay K8, the second end of the solid-state relay S1 is connected to the common connection point of the electromagnetic relay K8 and the electromagnetic relay K1, the first end of the pre-charging relay K2 is connected to the common connection point of the electromagnetic relay K8 and the electromagnetic relay K1, and the second end of the pre-charging relay K2 is connected to the common connection point of the electromagnetic relay K1 and the discharge positive interface HV+ through the resistor R; wherein, by setting the pre-charging relay K2, the circuit is pre-charged when the battery system is started to protect the circuit elements and ensure stability.

[0037] The positive electrode of the first power battery is connected to the common connection point of the electromagnetic relay K3 and the electromagnetic relay K8, the negative electrode of the first power battery is connected to the first end of the electromagnetic relay K7, and the second end of the electromagnetic relay K7 is connected to the discharge negative interface HV- through the electromagnetic relay K4;

[0038] The first end of the electromagnetic relay K6 is connected to the common connection point of the first power battery and the electromagnetic relay K7, and the second end of the electromagnetic relay K6 is connected to the common connection point of the electromagnetic relay K1 through the electromagnetic relay K5 and the electromagnetic relay K8;

[0039] The anode of the diode D1 is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, the cathode of the diode D1 is connected to the common connection point of the electromagnetic relay K5 and the electromagnetic relay K1, the first end of the solid-state relay S2 is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, and the second end of the solid-state relay S2 is connected to the common connection point of the electromagnetic relay K5 and the electromagnetic relay K1;

[0040] The positive pole of the second power battery is connected to the common connection point of the electromagnetic relay K6 and the electromagnetic relay K5, the negative pole of the second power battery is connected to the negative charging interface DC-, and the common connection point of the second power battery and the negative charging interface DC- is connected to the common connection point of the electromagnetic relay K7 and the electromagnetic relay K4.

[0041] The diode D1 is a power diode. The power diode is provided to prevent current backflow, and when switching between the charging battery and the discharging battery, for example, the current of the charging battery can be prevented from backflowing into the discharging battery, thereby protecting the charging battery from damage.

[0042] In this embodiment, the impact resistance of the solid-state relay is utilized, and the solid-state relay is closed during driving to realize the need for preliminary switching of the discharge mode during high-speed driving. The electromagnetic relay can be switched to meet the discharge demand in the next step; by preferentially closing the solid-state relay, the basic driving discharge demand is met, and after the voltages of the two branches where the dual power supply is located are balanced (usually completed within 30 seconds), the electromagnetic relay is switched, which solves the problem of easy generation of circulating current when the relay is closed in parallel in the dual branches, avoids the risk of relay adhesion, and is more in line with actual needs.

[0043] The solid-state relay S1 and the solid-state relay S2 can be replaced by electromagnetic relays. When the solid-state relays in the circuit are replaced by electromagnetic relays, the power inductance can be increased and the instantaneous current impact of the relay closing can be reduced.

[0044] It should be noted that the Figure 1 No insurance added, actually Figure 1 Adding insurance at each location can be understood as the same as this solution.

[0045] like Figure 2As shown, BAT1 partial discharge mode: when the difference between BAT1 voltage U1 and BAT2 voltage U2 is greater than the preset voltage value 1, by closing relays K1, K2, K4, K7, K8, and disconnecting the other relays, BAT1 and BAT2 can be discharged simultaneously, and BAT2 discharges through diode D1. Due to the unidirectional discharge characteristics of the diode, although U1>U2, BTA1 will not charge BTA2 to cause circulating current and overcurrent. When U1<U2, BAT2 discharges through the diode, which can keep the voltages of BAT1 and BAT2 balanced. At this time, BAT2 has no feedback current.

[0046] When U1-U2≤preset voltage value 1, the solid-state relay S2 is controlled to close. When the absolute value of the BAT2 current is less than the preset current value 1, the relay K5 is controlled to close, disconnect the solid-state relay S2, and enter the parallel discharge mode. Through the impact resistance of the solid-state relay S2, the BAT1 partial discharge mode is initially switched to the parallel discharge mode during driving. After the power branch current meets the conditions, it is switched to the electromagnetic relay path to enter the steady-state parallel discharge mode.

[0047] like Figure 3 As shown, BAT2 discharge mode: when the difference between BAT2 voltage U2 and BAT1 voltage U1 is greater than the preset voltage value 2, close relays K1, K4, K5 and enter BAT2 discharge mode; when U2-U1≤preset voltage value 2 and the absolute value of BAT2 current is less than the preset current value 1, disconnect relay K5, close relay K7 and solid-state relay S1; when the absolute value of BAT1 current is less than the preset current value 1, close relay K8 and disconnect solid-state relay S1 to enter BAT1 partial discharge mode. Through the impact resistance of solid-state relay S1, the initial switching from BAT2 discharge mode to BAT1 partial discharge mode is achieved during driving. After the power branch current meets the conditions, it is switched to the electromagnetic relay path to enter the steady-state BAT1 partial discharge mode.

[0048] like Figure 4 As shown, parallel discharge mode: when |U1-U2|≤preset voltage value 1, close relays K1, K4, K5, K7, and K8 to enter parallel discharge mode.

[0049] like Figure 5As shown, BAT1 charging mode: when the parallel charging mode U2-U1> preset voltage value 1, close relays K1, K3, K4, K7, K8, and enter BAT1 charging mode. When |U1-U2|≤ preset voltage value 1, reduce the charging request current to preset current value 2, close solid-state relay S2, and when the absolute value of BAT2 current is less than preset current value 1, close relay K5, disconnect solid-state relay S2, and enter parallel charging mode. Through the impact resistance characteristics of solid-state relay S2, the initial switch from BAT1 charging mode to parallel charging mode is realized. After the power branch current meets the conditions, it is switched to the electromagnetic relay path to enter the steady-state parallel charging mode.

[0050] like Figure 6 As shown, BAT2 charging mode: when the parallel charging mode U1-U2> preset voltage value 1, close relays K1, K3, K4, K5, K8 to enter BAT2 charging mode; when |U1-U2|≤preset voltage value 1, reduce the charging request current to preset current value 2, close relay K7, and enter parallel charging mode.

[0051] like Figure 7 As shown, parallel charging mode: when the parallel charging mode |U1-U2| ≤ the preset voltage value 1, the relays K1, K3, K4, K5, K7, and K8 are closed to enter the parallel charging mode.

[0052] like Figure 8 As shown, series charging mode: when the charging pile meets the series charging requirements, relays K1, K3, K4, K5, and K6 are closed to enter the series charging mode, and BAT2 is used to discharge the entire vehicle.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A dual power battery system, characterized in that: It includes a battery unit for providing electric energy, a control unit for controlling the flow of current, and a protection unit for protecting the battery system; The battery unit includes a first power battery and a second power battery; The control unit includes a number of relays; The protection unit includes a plurality of diodes.

2. The dual power battery system according to claim 1, characterized in that: The charging positive interface DC+ is connected to the first end of the relay K3, the second end of the relay K3 is connected to the first end of the relay K8, the second end of the relay K8 is connected to the first end of the relay K1, and the second end of the relay K1 is connected to the discharging positive interface HV+; The first end of relay S1 is connected to the common connection point of relay K3 and relay K8, the second end of relay S1 is connected to the common connection point of relay K8 and relay K1, the first end of relay K2 is connected to the common connection point of relay K8 and relay K1, and the second end of relay K2 is connected to the common connection point of relay K1 and discharge positive interface HV+ through resistor R; The positive electrode of the first power battery is connected to the common connection point of the relay K3 and the relay K8, the negative electrode of the first power battery is connected to the first end of the relay K7, and the second end of the relay K7 is connected to the discharge negative interface HV- through the relay K4; A first end of the relay K6 is connected to a common connection point of the first power battery and the relay K7, and a second end of the relay K6 is connected to a common connection point of the relay K1 through the relay K5 and the relay K8; The anode of the diode D1 is connected to the common connection point of the relay K6 and the relay K5, the cathode of the diode D1 is connected to the common connection point of the relay K5 and the relay K1, the first end of the relay S2 is connected to the common connection point of the relay K6 and the relay K5, and the second end of the relay S2 is connected to the common connection point of the relay K5 and the relay K1; The positive pole of the second power battery is connected to the common connection point of relay K6 and relay K5, the negative pole of the second power battery is connected to the negative charging interface DC-, and the common connection point of the second power battery and the negative charging interface DC- is connected to the common connection point of relay K7 and relay K4.

3. The dual power battery system according to claim 2, characterized in that: The relays K1, K3, K4, K5, K6, K7 and K8 are electromagnetic relays.

4. The dual power battery system according to claim 2, characterized in that: The relay K2 is a pre-charge relay.

5. The dual power battery system according to claim 2, characterized in that: The relays S1 and S2 are solid-state relays.

6. The dual power battery system according to claim 2, characterized in that: The diode D1 is a power diode.

7. The dual power battery system according to claim 5, characterized in that: The solid-state relay S1 is replaced by an electromagnetic relay.

8. The dual power battery system according to claim 5, characterized in that: The solid-state relay S2 is replaced by an electromagnetic relay.

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