Auxiliary power supply circuit of direct-current electric energy meter

Abstract

The utility model belongs to the technical field of circuits, and relates to an auxiliary power supply circuit of a direct-current electric energy meter, which comprises a switching power supply DC circuit, the switching power supply DC circuit is coupled with an alternating-current voltage input circuit and a direct-current voltage input circuit, and the alternating-current voltage input circuit is coupled with an ACL end and an ACN end. The alternating-current voltage input circuit comprises a variable resistor VR1, a capacitor CX1, an inductor L2, an inductor L3, a power supply internal resistor RS1 and a bridge rectifier DB1, the positive electrode of the bridge rectifier DB1 is connected with a switching power supply DC circuit, the negative electrode of the bridge rectifier DB1 is connected with a grounding end, the direct-current voltage input circuit is coupled with a DC + end and a DC-end, and the DC + end and the DC-end are connected with the capacitor CX1. The direct-current voltage input circuit comprises a diode DN6, a diode DN7, a booster circuit and an electrolytic capacitor EN2, and the electrolytic capacitor EN2 is connected with the switching power supply DC circuit; compared with the prior art, the utility model can reduce the variety of direct current meters, and reduce the material cost and management cost of a charging pile enterprise.

Description

TECHNICAL FIELD

[0001] The utility model relates to circuit technical field more specifically, it relates to a direct current electric energy meter auxiliary power supply circuit. BACKGROUND

[0002] With the national vigorously promotes the development of electric vehicles, and the matching direct current electric energy meter has also been widely applied.

[0003] The auxiliary power supply design of direct current electric energy meter usually needs to meet multiple power supply conditions to adapt to different application environments. For example, it can receive both high-voltage alternating current power supply and low-voltage direct current power supply. In order to realize the compatibility of this double power supply mode, the circuit design generally includes the following key parts:

[0004] 1. Multi-input power supply compatibility design: the circuit needs to be able to receive high-voltage alternating current (such as 220V AC) and low-voltage direct current (such as 5V to 60V DC). In order to achieve this, a rectifier circuit is usually set at the input end, which can convert alternating current into direct current, while allowing direct current to pass directly. This makes the circuit compatible with multiple input power supplies.

[0005] 2. Rectification and filtering: for high-voltage alternating current input, the rectifier circuit converts it into direct current and smooths the voltage waveform through a filter capacitor. For low-voltage direct current input, the rectification part may be bypassed because the direct current power supply itself does not need rectification. The filter circuit is still important to ensure a stable direct current voltage supply to the subsequent circuit.

[0006] 3. Voltage boosting or bucking circuit: in the electric energy meter, if a unified working voltage (for example, 80V DC) is needed, regardless of whether the input is high-voltage alternating current or low-voltage direct current, the circuit will include a voltage boosting or bucking converter. This allows the input voltage to be converted to the standard voltage required by the circuit.

[0007] 4. Power switching mechanism: the design may include a power switching mechanism that allows the use of a certain power supply to be prioritized when both high-voltage alternating current and low-voltage direct current power supplies are connected, or dynamically switches according to demand. This is usually achieved through control circuit or diode logic to ensure that the electric energy meter can obtain stable power supply in any case.

[0008] 5. Protection circuit: in order to ensure the safe operation of the electric energy meter, an overvoltage and overcurrent protection circuit is usually designed in the circuit to prevent the electric energy meter from being damaged due to power fluctuations or faults

[0009] This design is suitable for scenarios that need to adapt to different power supply environments, such as:

[0010] Some areas can only provide AC power, while in other cases low voltage DC power sources (such as solar cells, energy storage devices, etc.) can need to be used. In mobile or temporary installations, vehicle mounted power sources or batteries can be used.

[0011] However, due to the variety of charging columns, the auxiliary power supply of the DC electric energy meter is also complex. The auxiliary power supply of the DC electric energy meter can only use high voltage AC power or low voltage DC power, which has great limitations. Practical new type content

[0012] In view of the deficiencies in the prior art, the purpose of the utility model is to provide a DC electric energy meter auxiliary power supply circuit which can use both high voltage AC power and low voltage DC power.

[0013] To achieve the above purpose, the utility model provides the following technical scheme:

[0014] A DC electric energy meter auxiliary power supply circuit of a DC power supply, comprising a switching power supply DC circuit, the switching power supply DC circuit is coupled with an AC voltage input circuit and a DC voltage input circuit,

[0015] The AC voltage input circuit is coupled with AC_L and AC_N terminals, and the AC voltage input circuit comprises a variable resistor VR1, a capacitor CX1, an inductor L2 and an inductor L3, a power supply internal resistance RS1 and a bridge rectifier DB1, the positive electrode of the bridge rectifier DB1 is connected with the switching power supply DC circuit, and the negative electrode of the bridge rectifier DB1 is connected with the ground terminal,

[0016] The DC voltage input circuit is coupled with DC+ and DC- terminals, and the DC voltage input circuit comprises a diode DN6 and a diode DN7, a boost circuit and an electrolytic capacitor EN2, and the electrolytic capacitor EN2 is connected with the switching power supply DC circuit.

[0017] The utility model is further provided with: the AC_L, AC_N terminal is connected with variable resistor VR1, resistor VR1 and capacitor CX1 are connected in parallel, the positive electrode of inductor L2 is connected with capacitor CX1, the negative electrode of power supply internal resistance RS1 is connected with capacitor CX1,

[0018] The other end of inductor L2 and capacitor CX1 is connected with inductor L3, and the other end of inductor L3 is connected with bridge rectifier DB1.

[0019] The utility model is further provided with: the positive electrode of DC+ and DC- terminals is connected with diode DN6, the negative electrode of DC+ and DC- terminals is connected with the negative electrode of boost circuit, the positive electrode of boost circuit is connected with diode DN6, the other end positive electrode of boost circuit is connected with diode DN7, diode DN7 is connected with electrolytic capacitor EN2, and the other end negative electrode of boost circuit is connected with switching power supply DC circuit.

[0020] The utility model further sets up: input voltage range of alternating voltage input circuit is 80V to 265V.

[0021] The utility model further sets up: input voltage of direct current voltage input circuit is 5V to 60V.

[0022] Compared with the prior art, the utility model has the beneficial effects that:

[0023] By increasing two wiring ends, and two wiring ends are connected with direct current voltage input circuit and alternating voltage input circuit respectively, the variety of direct current meter can be reduced, and the material cost and management cost of charging pile enterprise are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] Fig. 1 It is alternating voltage input circuit structure schematic drawing of the utility model embodiment;

[0025] Fig. 2 It is direct current voltage input circuit structure schematic drawing of the utility model embodiment. DETAILED DESCRIPTION

[0026] The technical scheme in the utility model embodiments will be described clearly and completely below in conjunction with the drawings of the utility model embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the utility model.

[0027] In the description of the utility model, it is understood that the terms "up", "down", "front", "back", "left", "right", "top", "bottom", "in", "out" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the utility model.

[0028] As Figs. 1-2 Shown,

[0029] A direct current power supply DC power meter auxiliary power supply circuit, including switching power supply DC circuit, switching power supply DC circuit is coupled with alternating voltage input circuit and direct current voltage input circuit, the input voltage range of alternating voltage input circuit is 80V to 265V, the input voltage of direct current voltage input circuit is DC 5 to 60V.

[0030] The AC voltage input circuit is coupled with AC_L and AC_N terminals, and includes variable resistor VR1, capacitor CX1, inductor L2 and inductor L3, power supply internal resistance RS1 and bridge rectifier DB1. The positive terminal of the bridge rectifier DB1 is connected with the switching power supply DC circuit, and the negative terminal of the bridge rectifier DB1 is connected with the ground terminal.

[0031] The positive and negative terminals of the AC_L and AC_N terminals are connected with the variable resistor VR1. The variable resistor VR1 is used to limit the inrush current during starting. When the circuit is powered on, the resistance value is large to limit the inrush current. As the temperature of the circuit rises, the resistance value decreases, so that the resistance of the circuit during normal operation becomes very small.

[0032] The resistor VR1 and the capacitor CX1 are connected in parallel. The inductor L2 is connected with the positive terminal of the capacitor CX1, and the power supply internal resistance RS1 is connected with the negative terminal of the capacitor CX1. The capacitor CX1 is used to suppress electromagnetic interference in the alternating current. It is connected between the phase line and the zero line to filter high-frequency noise.

[0033] The inductor L2 and the other end of the capacitor CX1 are connected with the inductor L3. The inductor L3 converts the alternating current into a suitable voltage level.

[0034] The other end of the inductor L3 is connected with the bridge rectifier DB1. The inductor L2 is used to further suppress electromagnetic interference in the power supply line to protect the subsequent circuit from high-frequency noise.

[0035] The bridge rectifier DB1 is used to convert alternating current into direct current. The "AC1" and "AC2" terminals of DB1 receive alternating current from the primary winding of the L3 transformer, which is converted into direct current output through the internal diode network.

[0036] The DC voltage input circuit is coupled with DC+ and DC- terminals, and includes diode DN6 and diode DN7, boost circuit and electrolytic capacitor EN2. The electrolytic capacitor EN2 is connected with the switching power supply DC circuit.

[0037] The positive terminal of the DC+ and DC- terminals is connected with the diode DN6. The input voltage enters the circuit through the diode DN6 to prevent reverse connection protection.

[0038] The negative terminal of the DC+ and DC- terminals is connected with the negative terminal of the boost circuit. The positive terminal of the boost circuit is connected with the diode DN6. The boost circuit boosts the input direct current voltage to a higher voltage required.

[0039] The other end of the positive terminal of the boost circuit is connected with the diode DN7. The diode DN7 is connected with the electrolytic capacitor EN2. The other end of the negative terminal of the boost circuit is connected with the switching power supply DC circuit. DN7 is used to transmit the boosted voltage to the switching power supply DC circuit.

[0040] Working principle: when the electric energy meter is used in the charging pile, according to the on-site use environment, if AC 110V or AC 220V is used as the alternating current source, AC_L and AC_N are connected; if DC 5~60V is used as the direct current source, DC+ and DC- are connected, high-voltage alternating current rectification forms intermediate voltage DC 80V for POWER, low-voltage direct current source is also converted into intermediate voltage DC 80V for POWER; the diode in DB1 and DN7 form OR logic; the purpose that high-voltage alternating current source and voltage direct current source can supply power to the direct current electric energy meter is achieved.

[0041] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application, and any common change and replacement within the technical scheme range of the present application should be included in the protection range of the present application.

Claims

1. A DC power meter auxiliary power supply circuit for a DC power supply comprising a switching power supply DC circuit, characterized by: The switch power supply DC circuit is coupled with an alternating voltage input circuit and a direct voltage input circuit, The alternating voltage input circuit is coupled with AC_L and AC_N terminals, and comprises a variable resistor VR1, a capacitor CX1, inductors L2 and L3, a power supply internal resistor RS1 and a bridge rectifier DB1, the positive electrode of the bridge rectifier DB1 is connected with the switch power supply DC circuit, and the negative electrode of the bridge rectifier DB1 is connected with a ground terminal, The direct voltage input circuit is coupled with DC+ and DC- terminals, and comprises diodes DN6 and DN7, a boost circuit and an electrolytic capacitor EN2, the electrolytic capacitor EN2 is connected with the switch power supply DC circuit.

2. The DC power supply circuit for a DC energy meter auxiliary power supply circuit according to claim 1, characterized in that: The AC_L and AC_N terminals are connected with the variable resistor VR1, the resistor VR1 and the capacitor CX1 are connected in parallel, the inductor L2 is connected with the positive electrode of the capacitor CX1, and the power supply internal resistor RS1 is connected with the negative electrode of the capacitor CX1. The inductor L2 and the power supply internal resistor RS1 are both connected with one end of the inductor L3, and the other end of the inductor L3 is connected with the bridge rectifier DB1.

3. The DC power supply circuit for a DC energy meter auxiliary power supply circuit according to claim 2, characterized by: The DC+ terminal is connected with one end of the diode DN6, the DC- terminal is connected with one end of the boost circuit negative electrode, the other end of the boost circuit positive electrode is connected with the other end of the diode DN6, the other end of the boost circuit positive electrode is connected with one end of the diode DN7, the other end of the boost circuit negative electrode and the other end of the diode DN7 are both connected with the switch power supply DC circuit, one end of the electrolytic capacitor EN2 is connected with the other end of the diode DN7 and the switch power supply DC circuit, and the other end of the electrolytic capacitor EN2 is connected with the other end of the boost circuit negative electrode and the switch power supply DC circuit.

4. The DC power supply circuit for a DC energy meter auxiliary power supply circuit according to claim 3, characterized by: The input voltage range of the alternating voltage input circuit is 80V to 265V.

5. The DC power supply circuit for a DC energy meter auxiliary power supply circuit according to claim 4, characterized by: The input voltage of the direct voltage input circuit is 5V to 60V.

Images