Circuit structure for reducing standby reactive power of charging pile power supply module

Abstract

The invention relates to the field of charging pile power supply modules, and discloses a circuit structure for reducing standby reactive power of a charging pile power supply module, which comprises an alternating-current power grid, a relay assembly, an auxiliary power supply circuit with two power taking circuits and a filter circuit, and is characterized in that the alternating-current power grid is connected with the relay assembly, and the relay assembly is connected with the filter circuit; the two electricity taking circuits of the auxiliary power supply circuit are respectively connected with the relay assembly and the filter circuit, the relay assembly and the filter circuit output voltage to the auxiliary power supply circuit, during standby work, reactive power of the EMC filter circuit can be reduced, meanwhile, the control circuit is powered on, communication signals can be kept smooth, and starting can be conducted at any time; during normal work, a newly added auxiliary power supply electricity taking access can be cut off through the small relay, a better EMC filtering effect is obtained, and the electric energy conversion efficiency is higher.

Description

Technical Field

[0001] The present invention relates to the field of charging pile power modules, and in particular to a circuit structure for reducing the standby reactive power of a charging pile power module. Background Art

[0002] The AC input of the existing charging pile power module contains an EMC filter circuit. This part of the circuit will generate a large amount of capacitive reactive power when in standby mode (the main power circuit is not working), which will have a certain pollution effect on the power grid. There are currently two solutions. One is to add an AC contactor to the charging pile to disconnect the AC input of the charging power module when in standby mode; the other is to add a reactive compensator to the external power distribution device of the charging pile without an AC contactor to eliminate the reactive power in standby mode. The cost of high-power AC contactors and reactive compensators is relatively expensive. If a circuit can be added inside the charging power module to reduce the reactive power in standby mode, the cost of the charging pile system can be greatly reduced. For this reason, we propose a circuit structure for reducing the reactive power in standby mode of the charging pile power module. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention provides a circuit structure for reducing the standby reactive power of the charging pile power module. By adding a circuit, the reactive power generated by the EMC filter circuit during standby operation is reduced. At the same time, when the power module is working normally, the EMC can function normally to filter out high-frequency electromagnetic interference signals to the power grid. In addition, the constructed independent auxiliary power supply circuit can ensure that when the power module is working on standby, the communication circuit can be kept working normally and can receive communication signal instructions such as power on and off.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: a circuit structure for reducing the standby reactive power of a charging pile power module, comprising an AC power grid, a relay assembly, an auxiliary power supply circuit having two power supply circuits, and a filter circuit, the AC power grid is connected to the relay assembly, the relay assembly is connected to the filter circuit, the two power supply circuits of the auxiliary power supply circuit are respectively connected to the relay assembly and the filter circuit, and the relay assembly and the filter circuit output a low voltage to the auxiliary power supply circuit.

[0005] Preferably, the relay assembly includes a high-power relay, a control circuit and a small relay, the control circuit is electrically connected to the high-power relay and the small relay, and the AC power grid is electrically connected to the high-power relay and the small relay respectively.

[0006] Preferably, the auxiliary power supply circuit draws power from a small relay, the auxiliary power supply circuit is electrically connected to the control circuit, and the auxiliary power supply circuit outputs a low voltage to the control circuit.

[0007] Preferably, the high-power relay is connected to a filter circuit, the filter circuit includes an EMC filter circuit and a main power circuit, the main power circuit is electrically connected to the auxiliary power supply circuit, the main power circuit outputs voltage to the auxiliary power supply circuit, one of the power supply circuits of the auxiliary power supply circuit is connected between the EMC filter circuit and the main power circuit, and another power supply circuit of the auxiliary power supply circuit is connected to the small relay.

[0008] Preferably, the high-power relay may be a single relay or a plurality of relays used in parallel.

[0009] Compared with the prior art, the present invention provides a circuit structure for reducing the standby reactive power of the charging pile power module, which has the following beneficial effects: 1. The circuit structure for reducing the standby reactive power of the charging pile power module can reduce the reactive power of the EMC filter circuit when in standby mode. At the same time, the control circuit has power, which can keep the communication signal unobstructed and can be started at any time. During normal operation, the newly added auxiliary power supply path can be cut off through a small relay to obtain better EMC filtering effect and higher energy conversion efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the circuit structure of the present invention; Figure 2 It is a schematic diagram of the structure of the three-phase EMC filter of the present invention. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0012] See also Figure 1-2 A circuit structure for reducing the standby reactive power of a charging pile power module includes an AC power grid, a relay assembly, an auxiliary power supply circuit with two power supply circuits, and a filter circuit. The AC power grid is connected to the relay assembly, the relay assembly is connected to the filter circuit, the two power supply circuits of the auxiliary power supply circuit are respectively connected to the relay assembly and the filter circuit, and the relay assembly and the filter circuit output voltage to the auxiliary power supply circuit.

[0013] The relay assembly includes a high-power relay, a control circuit and a small relay. The control circuit is connected to the high-power relay and the small relay by electrical signals, and the AC power grid is electrically connected to the high-power relay and the small relay respectively.

[0014] The auxiliary power supply circuit is electrically connected to the small relay through a power supply circuit, and the auxiliary power supply circuit is electrically connected to the control circuit, and the small relay is connected to the control circuit for signal transmission.

[0015] When the circuit works in standby mode, the main power relay is disconnected, the small relay is closed, and the auxiliary power supply is powered by the independent circuit formed by the small relay. The control circuit has power and the communication function can be kept normal. At the same time, after the main power relay is disconnected, the connection between the EMC filter and the power grid is effectively segmented, reducing reactive power.

[0016] The high-power relay is connected to the filter circuit, the filter circuit includes an EMC filter circuit and a main power circuit, the main power circuit is electrically linked to the auxiliary power circuit, and one of the power-taking circuits of the auxiliary power circuit is connected between the EMC filter circuit and the main power circuit.

[0017] When the circuit is working normally with main power, the main power relay is closed, the low-power relay is disconnected, and the auxiliary power supply is powered from the main power circuit after the EMC filter, thereby improving the working efficiency of the power supply circuit; at the same time, after the main power is closed, the EMC circuit can effectively reduce the electromagnetic interference of the main power circuit to the power grid.

[0018] High-power relays can be a single relay or multiple relays can be used in parallel.

[0019] Working principle: In the charging pile power module, there are two relays, one for disconnecting the main power circuit and the other for disconnecting the auxiliary power supply circuit, both of which are controlled by the control circuit. The high-power relay is located between the AC power grid and the EMC filter, and the low-power relay is located between the AC power grid and the auxiliary power supply; in this way, the auxiliary power supply has two power supply circuits, one is connected to the small relay, and the other is connected between the EMC filter circuit and the main power circuit. When the circuit works in standby mode, the high-power relay is disconnected, the small relay is closed, and the auxiliary circuit power supply is powered from the independent circuit formed by the small relay. The control circuit has power and can maintain normal communication function; at the same time, after the main power relay is disconnected, the connection between the EMC filter and the power grid is effectively segmented, reducing reactive power. When the circuit is working normally with the main power, the high-power relay is closed, the small-power relay is disconnected, and the auxiliary power supply is powered from the main power circuit after the EMC filter circuit, improving the working efficiency of the power supply circuit; at the same time, after the main power is closed, the EMC filter circuit can well reduce the electromagnetic interference of the main power circuit to the power grid.

[0020] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A circuit structure for reducing the standby reactive power of a charging pile power module, characterized in that: It includes an AC power grid, a relay assembly, an auxiliary power supply circuit with two power supply circuits and a filter circuit. The AC power grid is connected to the relay assembly, the relay assembly is connected to the filter circuit, the two power supply circuits of the auxiliary power supply circuit are respectively connected to the relay assembly and the filter circuit, and the relay assembly and the filter circuit output voltage to the auxiliary power supply circuit.

2. A circuit structure for reducing the standby reactive power of a charging pile power module according to claim 1, characterized in that: The relay assembly comprises a high-power relay, a control circuit and a small relay. The control circuit is electrically connected to the high-power relay and the small relay. The AC power grid is electrically connected to the high-power relay and the small relay respectively.

3. A circuit structure for reducing the standby reactive power of a charging pile power module according to claim 2, characterized in that: The auxiliary power circuit draws power from the small relay, is electrically connected to the control circuit, and outputs a low voltage to the control circuit.

4. A circuit structure for reducing the standby reactive power of a charging pile power module according to claim 2, characterized in that: The high-power relay is connected to the filter circuit, the filter circuit includes an EMC filter circuit and a main power circuit, the main power circuit is electrically connected to the auxiliary power circuit, the main power circuit outputs a low voltage to the auxiliary power circuit, one of the power circuits of the auxiliary power circuit is connected between the EMC filter circuit and the main power circuit, and another power circuit of the auxiliary power circuit is connected to the small relay.

5. A circuit structure for reducing the standby reactive power of a charging pile power module according to claim 2, characterized in that: The high-power relay may be a single relay or a plurality of relays may be used in parallel.

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