Single-relay series-parallel connection switching circuit

Abstract

The utility model relates to the technical field of power electronics, in particular to a single-relay series-parallel switching circuit, which comprises at least two direct current output units, a state switching unit, a discharge unit and an anti-impact unit, and is characterized in that the direct current output units are connected with an output main circuit through the state switching unit; and the discharge unit and the anti-impact unit are respectively connected with the direct current output unit. According to the utility model, the size of the circuit can be reduced, the cost is reduced, and the control logic of the relay is simplified.

Description

A single relay series-parallel switching circuit Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a single relay series-parallel switching circuit. Background Technology

[0002] With the continuous advancement and innovation of science and technology, the demand for DC output power has shown a significant growth trend. In order to better adapt to the working environment of high voltage and high current, the series-parallel switching circuit technology of DC output has received widespread attention and application. This circuit technology can not only effectively improve the stability and reliability of the power system, but also show its unique advantages and importance in many demanding industrial applications, such as power transmission, large data centers and electric vehicle charging stations.

[0003] Existing series-parallel switching circuits generally require at least three relays to complete the series-parallel switching. For example, Chinese patent publication number CN110149041A discloses a series-parallel switching circuit and its control method, which realizes the series-parallel switching by controlling the on and off of relays S1-S5. However, the above-mentioned circuit is large in size, expensive, and the control logic of the relays is complex. Summary of the Invention

[0004] The purpose of this invention is to provide a single-relay series-parallel switching circuit that reduces circuit size, lowers cost, and simplifies relay control logic.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] In a first aspect, this utility model provides a single relay series-parallel switching circuit, including at least two DC output units, a state switching unit, a discharge unit, and an anti-surge unit. The DC output units are connected to the main output circuit through the state switching unit, and the discharge unit and the anti-surge unit are respectively connected to the DC output units.

[0007] In conjunction with the first aspect, optionally, the state switching unit is a single-pole double-throw relay.

[0008] In conjunction with the first aspect, optionally, a first DC output unit and a second DC output unit are included. The DC output unit is connected to the main output circuit through the state switching unit, including: the negative terminal of the first DC output unit is connected to the third pin of the single-pole double-throw relay; the positive terminal of the second DC output unit is connected to the fifth pin of the single-pole double-throw relay; the negative terminal of the second DC output unit is connected to the fourth pin of the single-pole double-throw relay; the positive terminals of the first and second DC output units are respectively connected to the positive terminal of the main output circuit through an anti-surge unit; the negative terminal of the second DC output unit is connected to the negative terminal of the main output circuit; the first pin of the single-pole double-throw relay is grounded; and the second pin of the single-pole double-throw relay is connected to the enable signal RLY_EN.

[0009] In conjunction with the first aspect, optionally, the shockproof unit includes diode D1 and diode D2, wherein the anode of diode D1 is connected to the positive terminal of the first DC output unit, the cathode of diode D1 is connected to the positive terminal of the main output circuit, the anode of diode D2 is connected to the positive terminal of the second DC output unit, and the cathode of diode D2 is connected to the positive terminal of the main output circuit.

[0010] In conjunction with the first aspect, optionally, the discharge unit includes diode D3, diode D4, resistor R1, and MOSFET Q1. The anode of diode D3 is connected to the positive terminal of the first DC output unit, the anode of diode D4 is connected to the positive terminal of the second DC output unit, the cathodes of diodes D3 and D4 are both connected to one end of resistor R1, the other end of resistor R1 is connected to the drain of MOSFET Q1, the source of MOSFET Q1 is connected to the negative terminal of the second DC output unit, and the gate of MOSFET Q1 is connected to the enable signal DISCHARGE.

[0011] The beneficial effects of this utility model are as follows: The DC output unit is connected to the main output circuit through the state switching unit, and the series-parallel connection state of the DC output unit is changed through the state switching unit. The discharge unit and the anti-surge unit are respectively connected to the DC output unit. When the system is in parallel state, the current is output to the outside through the anti-surge unit. When the system switches from parallel state to series state, the discharge circuit discharges the residual charge in the DC output unit. Therefore, the series-parallel switching circuit composed of the DC output unit, the state switching unit, the discharge unit and the anti-surge unit only requires a single relay to complete the stable switching of the series-parallel state, which indirectly reduces the circuit size, reduces the cost and simplifies the relay control logic. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0013] Figure 1 is a circuit diagram of this utility model;

[0014] Figure 2 is a signal diagram of each unit in this utility model;

[0015] The markings in the diagram are: 1 for the first DC output unit, 2 for the second DC output unit, 3 for the state switching unit, 4 for the discharge unit, and 5 for the anti-impact unit. Detailed Implementation

[0016] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments and specific features in the embodiments are detailed descriptions of the technical solution of this application, rather than limitations thereof.

[0017] In the description of this utility model, the terms "first" and "second" are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features or the order of the technical features.

[0018] In the description of this utility model, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0019] As shown in Figure 1, this utility model provides a single relay series-parallel switching circuit, including at least two DC output units, a state switching unit 3, a discharge unit 4, and an anti-surge unit 5. The DC output units are connected to the main output circuit through the state switching unit 3, and the discharge unit 4 and the anti-surge unit 5 are respectively connected to the DC output units.

[0020] In some embodiments, as shown in FIG1, the state switching unit is a single-pole double-throw relay; the single-relay series-parallel switching circuit includes a first DC output unit 1 and a second DC output unit 2. The negative terminal of the first DC output unit 1 is connected to the third pin of the single-pole double-throw relay, the positive terminal of the second DC output unit 2 is connected to the fifth pin of the single-pole double-throw relay, and the negative terminal of the second DC output unit 2 is connected to the fourth pin of the single-pole double-throw relay. The positive terminals of the first DC output unit 1 and the second DC output unit 2 are respectively connected to the positive terminal of the main output circuit through an anti-impact unit, and the negative terminal of the second DC output unit 2 is connected to the negative terminal of the main output circuit. The first pin of the single-pole double-throw relay is grounded, and the second pin of the single-pole double-throw relay is connected to the enable signal RLY_EN.

[0021] The shockproof unit 5 includes diodes D1 and D2. The anode of diode D1 is connected to the positive terminal of the first DC output unit, and the cathode of diode D1 is connected to the positive terminal of the main output circuit. The anode of diode D2 is connected to the positive terminal of the second DC output unit, and the cathode of diode D2 is connected to the positive terminal of the main output circuit.

[0022] The discharge unit 4 includes diodes D3 and D4, resistor R1 and MOSFET Q1. The anode of diode D3 is connected to the positive terminal of the first DC output unit, and the anode of diode D4 is connected to the positive terminal of the second DC output unit. The cathodes of diodes D3 and D4 are both connected to one end of resistor R1, and the other end of resistor R1 is connected to the drain of MOSFET Q1. The source of MOSFET Q1 is connected to the negative terminal of the second DC output unit, and the gate of MOSFET Q1 is connected to the enable signal DISCHARGE.

[0023] The working principle of this utility model is as follows:

[0024] As shown in Figure 2, before time T0, the RLY_EN signal is low and the coil voltage of the single-pole double-throw relay is 0V. The third and fourth pins of the single-pole double-throw relay are short-circuited. At this time, the system is in parallel. The first DC output unit outputs current through diode D1 and the second DC output unit outputs current through diode D2.

[0025] When the system switches from parallel to series connection, at time T0, the first and second DC output units (DC VOUT1 and DC VOUT2 as shown in Figure 1) are first turned off. Then, the discharge unit is activated, the Discharge signal goes high, the MOSFET Q1 is triggered, and DS is in the on state. The residual charge of capacitors C1 and C2 in the first and second DC output units is discharged in the form of heat through diodes D3 and D4 in resistor R1. Until time T1, when the system detects that the voltage of capacitors C1 and C2 has dropped to a certain low value, Discharge goes low, the discharge circuit stops working, and then the RLY_EN signal goes high, the coil of the single-pole double-throw relay is energized. At this time, the third and fifth pins of the single-pole double-throw relay are in contact. Delay until time T2 to ensure that the relay has been energized, and the first and second DC output units are turned on. At this time, the system is in series connection, the current is output from diode D1, and diode D2 is in reverse bias and no current flows through it.

[0026] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A single-relay series-parallel switching circuit, characterized in that, It includes at least two DC output units, a state switching unit, a discharge unit, and an anti-surge unit. The DC output units are connected to the main output circuit through the state switching unit, and the discharge unit and the anti-surge unit are respectively connected to the DC output units.

2. The single-relay series and shunt switching circuit of claim 1, wherein, The state switching unit is a single-pole double-throw relay.

3. The single-relay series-parallel switching circuit according to claim 2, characterized in that, The system includes a first DC output unit and a second DC output unit. The DC output units are connected to the main output circuit via the state switching unit. Specifically, the negative terminal of the first DC output unit is connected to the third pin of a single-pole double-throw relay, the positive terminal of the second DC output unit is connected to the fifth pin of the single-pole double-throw relay, and the negative terminal of the second DC output unit is connected to the fourth pin of the single-pole double-throw relay. The positive terminals of the first and second DC output units are connected to the positive terminal of the main output circuit via an anti-surge unit, and the negative terminal of the second DC output unit is connected to the negative terminal of the main output circuit. The first pin of the single-pole double-throw relay is grounded, and the second pin of the single-pole double-throw relay is connected to the enable signal RLY_EN.

4. The single relay series-parallel switching circuit according to claim 3, characterized in that, The shockproof unit includes diodes D1 and D2. The anode of diode D1 is connected to the positive terminal of the first DC output unit, and the cathode of diode D1 is connected to the positive terminal of the main output circuit. The anode of diode D2 is connected to the positive terminal of the second DC output unit, and the cathode of diode D2 is connected to the positive terminal of the main output circuit.

5. The single relay series-parallel switching circuit according to claim 3 or 4, characterized in that, The discharge unit includes diodes D3 and D4, resistor R1, and MOSFET Q1. The anode of diode D3 is connected to the positive terminal of the first DC output unit, and the anode of diode D4 is connected to the positive terminal of the second DC output unit. The cathodes of diodes D3 and D4 are both connected to one end of resistor R1, and the other end of resistor R1 is connected to the drain of MOSFET Q1. The source of MOSFET Q1 is connected to the negative terminal of the second DC output unit, and the gate of MOSFET Q1 is connected to the enable signal DISCHARGE.

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