Standby-loss-free mobile power supply

Abstract

The invention discloses a standby-loss-free mobile power supply which comprises a battery pack and an inversion device, a capacitor is arranged in the inversion device, the positive electrode of the battery pack is connected with the positive electrode of the capacitor, the negative electrode of the battery pack is connected with the negative electrode of the capacitor, and a starting charging resistor and a first starting switch are connected between the negative electrode of the battery pack and the negative electrode of the capacitor in series. A loop is further formed between the positive electrode and the negative electrode of the capacitor through a coil of a contactor, a second starting switch is connected in the loop in series, and a normally-open main contact of the contactor is connected with the starting charging resistor in parallel. By adopting the standby-loss-free mobile power supply, standby loss can be avoided, and contact cremation can be prevented from being generated when the alternating-current power supply starting switch is switched on.

Description

Technical Field

[0001] The present invention relates to a mobile power supply, and more particularly to a mobile power supply with AC output. Background Art

[0002] A mobile power supply generally includes a battery pack and an inverter device. The battery pack stores electrical energy and can provide power for DC or AC electrical appliances, and its application is becoming increasingly widespread. When an AC power supply is required from the mobile power supply, the DC electrical energy in the battery pack is converted into AC electrical energy through the inverter device to supply power to the AC electrical appliance. In order to ensure the quality of the output AC power, obtain a pure sine wave of AC power, and store a certain amount of energy to ensure the stable operation of the inverter device, and to protect the components in the circuit and prevent the circuit components from being damaged by overcurrent or overvoltage, a capacitor with a certain capacity is provided in the inverter device. The inverter device is connected to the battery pack and is always in a standby state, which will inevitably cause continuous current loss and result in the loss of battery capacity. In addition, due to the presence of the capacitor in the inverter device, during the manufacturing and assembly process of the mobile power supply, when the battery pack is connected to the inverter device, a large current will be generated at the contact point due to the charging of the capacitor, and contact sparks will be generated at the contact point of the two-part circuit connection, which is extremely unfavorable for the assembly operation, and the same problem will also occur during subsequent maintenance operations. Isolating the battery pack and the inverter device through an AC power supply start switch can solve the problem of battery capacity loss caused by standby loss of the mobile power supply. However, when the mobile power supply needs to enter the AC output working state and this switch is turned on, due to the large capacitor charging current formed by the charging of the capacitor in the inverter device, contact sparks will also be generated at the contact point of the switch, and even the set switch will be burned out, causing the mobile power supply to malfunction. Summary of the Invention

[0003] Aiming at the above deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a mobile power supply without standby loss, which can avoid standby loss and prevent contact sparks from being generated when the AC power supply start switch is turned on.

[0004] To solve the above technical problem, a mobile power supply without standby loss of the present invention includes a battery pack and an inverter device. A capacitor is provided in the inverter device. The positive electrode of the battery pack is connected to the positive electrode of the capacitor, and the negative electrode of the battery pack is connected to the negative electrode of the capacitor. A starting charging resistor and a starting switch one are connected in series between the negative electrode of the battery pack and the negative electrode of the capacitor. A loop is also formed between the positive electrode and the negative electrode of the capacitor through the coil of a contactor, and a starting switch two is connected in series in this loop. The normally open main contact of the contactor is connected in parallel with the starting charging resistor.

[0005] After adopting the above technical solution, when the mobile power supply needs to output alternating current, the start switch one and the start switch two can be closed. At this time, the capacitor and the battery pack form a loop through the start charging resistor. The battery pack will charge the capacitor with a small current through the start charging resistor, avoiding the possibility of contact sparks at the switch contacts caused by directly setting a start switch between the battery pack and the inverter device and the capacitor charging with a large current rapidly. When the capacitor is fully charged through the start charging resistor, the potential at both ends of the capacitor is correspondingly equal to the potential at both ends of the battery pack. The coil of the contactor is energized and connected, driving the normally open main contact of the contactor to close. Since the potential between the negative pole of the battery pack and the negative pole of the capacitor is equal at this time, no contact sparks will be generated when the normally open main contact of the contactor closes. A path is formed between the negative pole of the battery pack and the negative pole of the capacitor through the closed normally open main contact of the contactor. The battery pack and the inverter device are smoothly connected, and the mobile power supply can output alternating current normally. At the same time, the coil of the contactor also remains energized and connected, and the normally open main contact of the contactor will remain closed to ensure the continuous output of alternating current of the mobile power supply. When the mobile power supply no longer needs to output alternating current, the start switch one and the start switch two are disconnected. On the one hand, the loop between the coil of the contactor and the capacitor is disconnected, the coil of the contactor loses power, and the normally open main contact of the contactor will open simultaneously, disconnecting the path formed between the negative pole of the battery pack and the negative pole of the capacitor through the normally open main contact of the contactor. On the other hand, the path formed between the negative pole of the battery pack and the negative pole of the capacitor through the start charging resistor is also disconnected simultaneously. In this way, the connection relationship between the inverter device and the battery pack is completely disconnected, ensuring that no current loss occurs in the battery pack.

[0006] In a preferred embodiment of the present invention, the coil voltage of the contactor is consistent with the battery pack voltage. By adopting this embodiment, the contactor can only be energized and act to close its normally open main contact when the capacitor is charged to the same potential as the battery pack, ensuring that no contact sparks will occur when its normally open main contact closes.

[0007] In another preferred embodiment of the present invention, the rated current of the normally open main contact of the contactor is consistent with the operating current of the inverter device. By adopting this embodiment, it can be ensured that the current that the normally open main contact of the contactor can pass through will not be burned out due to being less than the current during the normal operation of the inverter device, nor will it be wasted due to being much greater than the current during the normal operation of the inverter device.

[0008] In still another preferred embodiment of the present invention, the resistance value of the start charging resistor is matched with the operating voltage and power of the inverter device. By adopting this embodiment, it can be ensured that the start charging resistor can meet the requirement of charging the capacitor in the inverter device with an appropriate current.

[0009] A further preferred embodiment of the present invention is that the battery pack is a lithium battery pack. With this embodiment, the lithium battery pack is composed of lithium batteries, which has high energy density, long service life, light weight, is green and environmentally friendly, and has excellent performance.

[0010] Another further preferred embodiment of the present invention is that the first start switch and the second start switch are two single-pole switches in the same double-pole single-throw switch. With this embodiment, the first start switch and the second start switch are constituted by a double-pole single-throw switch, and both installation and use are very convenient.

[0011] Yet another further preferred embodiment of the present invention is that the normally open main contact of the contactor is connected in parallel with the start charging resistor and the first start switch. With this embodiment, the first start switch can adopt a control switch with a small current, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The following further describes the mobile power supply without standby loss of the present invention in detail with reference to the drawings and specific embodiments.

[0013] Figure 1 It is a schematic structural diagram of a specific embodiment of the mobile power supply without standby loss of the present invention.

[0014] In the figure: 1 - battery pack, 2 - start charging resistor, 31 - coil of the contactor, 32 - normally open main contact of the contactor, 41 - first start switch, 42 - second start switch, 5 - inverter device, 51 - capacitor. SPECIFIC EMBODIMENTS

[0015] In Figure 1In the mobile power supply without standby loss shown, the battery pack 1 is a lithium battery pack composed of a plurality of lithium batteries. The inverter device 5 is a device that converts the DC electrical energy in the battery pack 1 into AC electrical energy. A capacitor 51 is provided in the inverter device 5. The positive electrode of the battery pack 1 is connected to the positive electrode of the capacitor 51. A starting charging resistor 2 and a first starting switch 41 are connected in series between the negative electrode of the battery pack 1 and the negative electrode of the capacitor 51. In this way, the negative electrode of the battery pack 1 is connected to the negative electrode of the capacitor 51 through the starting charging resistor 2 and the first starting switch 41. The resistance value of the starting charging resistor 2 should match the working voltage and power of the inverter device 5. A contactor is also provided between the battery pack 1 and the inverter device 5. A loop is formed between the positive electrode and the negative electrode of the capacitor 51 through the coil 31 of the contactor. The voltage requirement of the coil 31 of the contactor is consistent with the voltage of the battery pack 1. A second starting switch 42 is connected in series in this loop. The normally open main contact 32 of the contactor is connected in parallel with the starting charging resistor 2, and the rated current requirement of the normally open main contact 32 of the contactor is consistent with the working current of the inverter device 5. As a preferred embodiment, the normally open main contact 32 of the contactor is connected in parallel with the starting charging resistor 2 and the first starting switch 41. The first starting switch 41 and the second starting switch 42 are two single-pole switches in the same double-pole single-throw switch. The double-pole single-throw switch is preferably a boat-shaped switch with 2 channels having 2 moving contacts and 2 static contacts. One of the moving contacts and one of the static contacts serve as the first starting switch 41, and the other moving contact and the other static contact serve as the second starting switch 42. Operating the boat-shaped switch can cause the first starting switch 41 and the second starting switch 42 to act simultaneously.

[0016] Only some preferred embodiments of the present invention are listed above, but the present invention is not limited thereto, and many improvements and transformations can be made. As long as the improvements and transformations are made based on the basic principle of the present invention, they should be regarded as falling within the protection scope of the present invention.

Claims

1. A mobile power supply without standby loss, comprising a battery pack (1) and an inverter device (5). A capacitor (51) is provided in the inverter device (5). The positive electrode of the battery pack (1) is connected to the positive electrode of the capacitor (51), and the negative electrode of the battery pack (1) is connected to the negative electrode of the capacitor (51). Characterized in that: A starting charging resistor (2) and a starting switch one (41) are connected in series between the negative electrode of the battery pack (1) and the negative electrode of the capacitor (51). A loop is also formed through the coil (31) of the contactor between the positive electrode and the negative electrode of the capacitor (51). A starting switch two (42) is connected in series in this loop. The normally open main contact (32) of the contactor is connected in parallel with the starting charging resistor (2).

2. The mobile power supply without standby loss according to claim 1, Characterized in that: The voltage of the coil (31) of the contactor is consistent with the voltage of the battery pack (1).

3. The mobile power supply without standby loss according to claim 1 or 2, Characterized in that: The rated current of the normally open main contact (32) of the contactor is consistent with the working current of the inverter device (5).

4. The mobile power supply without standby loss according to claim 1, Characterized in that: The resistance value of the starting charging resistor (2) is matched with the working voltage and power of the inverter device (5).

5. The mobile power supply without standby loss according to claim 1, Characterized in that: The battery pack (1) is a lithium battery pack.

6. The mobile power supply without standby loss according to claim 1, Characterized in that: The starting switch one (41) and the starting switch two (42) are two single-pole switches in the same double-pole single-throw switch.

7. The mobile power supply without standby loss according to claim 1, Characterized in that: The normally open main contact (32) of the contactor is connected in parallel with the starting charging resistor (2) and the starting switch one (41).

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