Low-power-consumption standby control circuit adaptive to new and old charging piles

Abstract

The invention relates to the technical field of electric vehicle charging equipment, in particular to a low-power-consumption standby control circuit adaptive to new and old charging piles. The circuit comprises a main loop control unit, a pre-charging control unit, an EMC filtering unit, a main power rectification unit, a zero power consumption control unit, a low power consumption control unit, an auxiliary power supply unit and an auxiliary rectification unit. Through the relay combination design of the main loop control unit, the zero-power-consumption control unit and the low-power-consumption control unit, dual-mode switching of zero power consumption and low power consumption in a standby state is realized. The module does not need to replace a magnetic latching relay or newly add an auxiliary power supply system, an old charging pile can directly achieve low power consumption (zero reactive power + low active power), a new charging pile achieves zero power consumption (zero reactive power + zero active power) through a 12V driving signal, standby power consumption and design cost are remarkably reduced, and the method is suitable for energy efficiency optimization of various non-vehicle-mounted chargers.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle charging equipment, and in particular to a low-power standby control circuit adapted to new and old charging piles. Background Art

[0002] The standby power consumption of electric vehicle charging equipment is a growing concern. Off-board chargers may maintain some circuitry (such as communication modules, EMI filtering circuits, and MCUs) even when no vehicle is connected or charging is complete, resulting in continuous standby power consumption (5W-20W active power and 300Var-600Var reactive power). This standby power consumption not only increases user electricity costs but also reduces equipment lifespan and violates increasingly stringent energy efficiency regulations (such as the EU ErP directive, which requires standby power consumption to be ≤0.5W).

[0003] At present, existing technologies all have certain defects. For example, low-power solutions based on power management chips (PMICs) use low-power PMICs to achieve low standby active power consumption, but the PMIC, wake-up circuit, and signal detection module still require microampere-level static current, which cannot achieve zero active power consumption, and the reactive power consumption is not reduced. Magnetic latching relay solution: By cutting off the main circuit through the magnetic latching relay, zero power consumption can be achieved in theory, but there are the following defects: driving a single high-power magnetic latching relay requires more than 3W of power, which increases the difficulty of power management design of the charging pile; after the magnetic latching relay is placed at the front end, the power-on process cannot be pre-charged, and the instantaneous impact current when the relay is attracted can reach hundreds of A, affecting its service life; the high cost of magnetic latching relays leads to an increase in the cost of the entire pile life cycle; when the mains power or control signal is abnormal, the relay may not be reset in time, causing a surge current risk. In order to enable the old charging pile to achieve the low-power mode of "zero reactive loss + low active loss" without modification, and at the same time allow the new charging pile to add a 12V drive signal to achieve the zero-power mode of "zero reactive loss + zero active loss", reduce the design cost and drive power, and improve the system reliability and compatibility, therefore, we propose a low-power standby control circuit suitable for new and old charging piles. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the existing solutions, such as the low-power solution based on the power management chip cannot achieve zero power consumption, and the magnetic latching relay solution has defects such as large driving power, high cost, and short life. In order to enable old charging piles to achieve the low-power mode of "zero reactive loss + low active loss" without modification, the design cost and driving power are reduced, and the system reliability and compatibility are improved.

[0005] To achieve the above objectives, the present invention provides a low-power standby control circuit that is compatible with new and old charging piles, including a main circuit control unit, a pre-charge control unit, an EMC filter unit, a main power rectifier unit, a zero-power control unit, a low-power control unit, an auxiliary power supply unit, and an auxiliary rectifier unit. The main circuit control unit is pre-placed at the input port to control the switch of the EMC filter unit. The zero-power control unit and the low-power control unit are arranged in series to control the on and off of the auxiliary rectifier unit. The auxiliary power supply unit provides input for the auxiliary filter unit in standby mode.

[0006] In standby mode, the main circuit control unit is disconnected and the EMC filter unit is cut off to eliminate reactive power loss. If the charging pile provides a 12V drive signal, the zero-power control unit is disconnected, and the module is completely cut off from the mains to achieve zero active power loss. If the charging pile does not provide a 12V drive signal, the zero-power control unit is closed, the auxiliary rectifier unit works, and the module enters a low active power loss mode. When the power is turned on, the pre-charge control unit is first energized to pre-charge the capacitor of the EMC filter unit through the pre-charge resistor. After the pre-charge is completed, the main circuit control unit is energized to connect the main power rectifier unit. After the main circuit is connected, the low-power control unit is disconnected, and the auxiliary rectifier unit is cut off. The main power rectifier unit takes over the power supply of the auxiliary power supply unit.

[0007] Compared with the prior art, the present invention has the following beneficial effects:

[0008] 1. This low-power standby control module, which is compatible with both new and existing charging piles, controls the disconnection of relays JK1, JK2, and JK3 through the main circuit control unit, disconnecting the EMC filter unit to achieve zero reactive power loss. The series design of the zero-power control unit and the low-power control unit enables adaptive dual-mode switching between "zero power" and "low power" (compatibility with both new and existing charging piles). It uses non-magnetic latching power relays and low-power relays to replace high-cost magnetic latching relays, reducing hardware costs and avoiding the risk of abnormal resets.

[0009] 2. The pre-charge control unit pre-charges the EMC filter capacitor at startup to eliminate the inrush current when the main relay is energized, extending the relay life. In standby mode, the auxiliary rectifier unit provides low-load input. After startup, it switches to the main power rectifier unit, ensuring low standby power consumption while avoiding overload of the auxiliary rectifier unit, thereby improving system reliability.

[0010] As a further improvement of the present technical solution, the main circuit control unit receives the control signal output by the DSP, and controls the disconnection and connection of the AC power and the main power circuit by controlling the conduction and disconnection of the non-magnetic power relay JK1, the non-magnetic power relay JK2 and the non-magnetic power relay JK3.

[0011] As a further improvement of the present technical solution, the pre-charge control unit adopts non-magnetic holding normally open low-power relays JK8, JK9 and pre-charge resistors R3, R4 to pre-charge the capacitor of the EMC filter unit before the non-magnetic power relay JK2 and the non-magnetic power relay JK3 are energized.

[0012] The beneficial effect of adopting the above further improvement is that, if not pre-charged, the X capacitors (CX1-CX6) and busbar electrolytic capacitors (CD1-CD2) of the EMC filter unit are in a zero voltage state at the moment of power-on. When the main relay is energized, the AC power will directly charge the capacitors through the main power rectifier unit, generating an inrush current of up to 200A. When the large current passes through the relay contacts, a strong arc will be generated, causing the contact metal to melt and burn. Long-term use can easily cause contact adhesion (the relay cannot be disconnected) or increase contact resistance (increased heat loss).

[0013] As a further improvement of the present technical solution, the EMC filter unit includes a common mode inductor L4;

[0014] The upper left end of the common-mode inductor L4 is connected to one end of the capacitor CX2, and is connected in parallel to one end of the capacitor CY3 and one end of the capacitor CX1. The left middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX2 and one end of the capacitor CX3, and is connected in parallel to one end of the capacitor CY2. The lower left end of the common-mode inductor L4 is connected to the other end of the capacitor CX3, and is connected in parallel to the other end of the capacitor CX1 and one end of the capacitor CY1.

[0015] The upper right end of the common-mode inductor L4 is connected to one end of the capacitor CX5, and is connected to one end of the capacitor CY4 and one end of CX4. The right middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX5 and one end of CX6, and is connected to one end of the capacitor CY5. The lower right end of the common-mode inductor L4 is connected to the other end of the capacitor CX6, and is connected to the other end of the capacitor CX4 and one end of the capacitor CY6.

[0016] As a further improvement of the technical solution, the main power rectifier unit includes a PFC inductor L1, a PFC inductor L2 and a PFC inductor L3;

[0017] One end of the PFC inductor L1 is connected to the anode of the diode D1 and to the cathode of the diode D4. One end of the PFC inductor L2 is connected to the anode of the diode D2 and to the cathode of the diode D5. One end of the PFC inductor L3 is connected to the anode of the diode D3 and to the cathode of the diode D6. The cathode of the diode D3 is connected to the cathode of the diode D1 and the cathode of the diode D2, and to one end of the capacitor CD1. The other end of the capacitor CD1 is connected to one end of the capacitor CD2. The other end of the capacitor CD2 is connected to the anode of the diode D4 and the anode of the diode D5, and to the anode of the diode D6.

[0018] The beneficial effect of adopting the above-mentioned further improvements is that when the charging module is operating, the high-frequency switching action of the power devices (such as IGBTs) will generate common-mode (CM) and differential-mode (DM) electromagnetic interference with a frequency range of 10kHz to 30MHz. The EMC filter unit can suppress this interference. After being attenuated by the EMC filter unit, interference such as lightning surges and harmonics in the power grid can be prevented from causing malfunctions to the module's internal DSP, sampling circuits and other precision components.

[0019] The main power rectifier unit consists of PFC inductors (L1-L3) and power rectifier diodes (D1-D6), which converts three-phase 380V AC power into pulsating DC voltage (about 310V), which is filtered by bus electrolytic capacitors (CD1-CD2) and then supplies power to the main power circuit.

[0020] As a further improvement of the present technical solution, the zero-power control unit includes a non-magnetic holding normally closed relay JK4 and a non-magnetic holding normally closed relay JK6, which controls the on and off of relay JK4 and relay JK6 through the 12V drive signal provided by the charging pile to control the input power supply of the auxiliary rectifier unit.

[0021] As a further improvement of the present technical solution, the low-power control unit includes a non-magnetic holding normally closed relay JK5 and a non-magnetic holding normally closed relay JK7, which are controlled by a DSP chip. When in standby mode, relay JK5 and relay JK7 are normally closed. The power consumption mode is switched according to the state of the zero-power control unit. After power-on, relay JK5 and relay JK7 are disconnected to cut off the auxiliary rectifier unit.

[0022] The beneficial effect of adopting the above further improvement is that the AC input of the auxiliary rectifier unit is disconnected by the relay, so that the module is completely isolated from the mains power when in standby mode, eliminating the active power loss of the main power rectifier unit, auxiliary power supply unit, etc.

[0023] When the charging pile does not provide a 12V drive signal, the low-power control unit remains normally closed, allowing the auxiliary rectifier unit to work, providing a low-load input for the auxiliary power supply (power consumption <8W), maintaining low-frequency communication between the module and the charging pile (such as CAN signal heartbeat packets), and meeting the standby requirements of the old charging pile;

[0024] The zero-power control unit (JK4-JK6) and the low-power control unit (JK5-JK7) are connected in series in the input circuit of the auxiliary rectifier unit. The zero-power unit is disconnected → regardless of the status of the low-power unit, the auxiliary rectifier unit is powered off → zero-power mode, the zero-power unit is closed + the low-power unit is closed → the auxiliary rectifier unit works → low-power mode, after starting up the low-power unit is disconnected → the auxiliary rectifier unit is bypassed → the main power circuit is powered.

[0025] As a further improvement of the present technical solution, the auxiliary rectifier unit includes a diode D7, a diode D8, a diode D9 and a diode D10;

[0026] The cathode of the diode D7 is connected to the cathode of the diode D8 and is connected in parallel to one end of the resistor R1. The other end of the resistor R1 is connected to one end of the capacitor CD3. The other end of the capacitor CD3 is connected to one end of the capacitor CD4. The other end of the capacitor CD4 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the anode of the diode D9 and is connected in parallel to the anode of the diode D10. The cathode of the diode D9 is connected to the anode of the diode D7. The cathode of the diode D10 is connected to the anode of the diode D8.

[0027] As a further improvement of the present technical solution, the zero-power control unit and the low-power control unit both use low-power relays with a driving power less than 0.5W, which are adapted to the charging pile control power supply design.

[0028] As a further improvement of the present technical solution, the auxiliary rectifier unit adopts a time-sharing multiplexing strategy. When in standby mode, the auxiliary rectifier unit provides low-load input. After startup, it switches to the main power rectifier unit to avoid overload of the auxiliary rectifier unit.

[0029] The beneficial effect of adopting the above further improvement is that the auxiliary rectifier unit consists of rectifier diodes (D7-D10), current-limiting resistors (R1-R2) and electrolytic capacitors (CD3-CD4). In standby mode, it rectifies the AC input to a DC bus voltage (approximately 310V), providing a low-load input (power <1W) for the auxiliary power supply unit. At this time, the auxiliary power supply only needs to maintain the operation of basic circuits such as the DSP main control chip and communication module (such as CAN signal heartbeat packets), ensure that the module maintains a communication connection with the charging station, and wait for the power-on command;

[0030] In standby mode, the auxiliary rectifier unit operates at low power consumption, providing only a low-load input of less than 1W for the auxiliary power supply. Compared with the 5-10W active power loss generated by the continuous operation of the main power rectifier unit in the traditional solution, the power consumption is reduced by more than 80%. After startup, the main power rectifier unit takes over the high load. When the auxiliary power load increases to 5-10W, it is powered by the main power rectifier unit and the auxiliary rectifier unit is bypassed, avoiding efficiency loss of the low-power circuit under high load.

[0031] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0033] Figure 2Schematic diagram of circuit connections between units of the present invention;

[0034] Figure 3 It is a schematic diagram of unit connection of the present invention.

[0035] The meaning of each number in the figure is:

[0036] 100, main circuit control unit; 200, pre-charge control unit; 300, EMC filter unit; 400, main power rectifier unit; 500, zero power control unit; 600, low power control unit; 700, auxiliary power supply unit; 800, auxiliary rectifier unit. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0038] At present, among the existing solutions, the low-power solution based on power management chips cannot achieve zero power consumption, and the magnetic latching relay solution has defects such as large driving power, high cost, and short life. In order to enable old charging piles to achieve the low-power mode of "zero reactive loss + low active loss" without modification, reduce design costs and driving power, and improve system reliability and compatibility.

[0039] Therefore, the present invention proposes that, in the standby state, the main circuit control unit is disconnected, and the EMC filter unit is cut off to eliminate reactive loss. If the charging pile provides a 12V drive signal, the zero-power control unit is disconnected, and the module is completely cut off from the mains to achieve zero active power loss. If the charging pile does not provide a 12V drive signal, the zero-power control unit is closed, the auxiliary rectifier unit works, and the module enters a low active power loss mode. When the power is turned on, the pre-charge control unit is first energized to pre-charge the capacitor of the EMC filter unit through the pre-charge resistor. After the pre-charge is completed, the main circuit control unit is energized to connect the main power rectifier unit. After the main circuit is connected, the low-power control unit is disconnected, and the auxiliary rectifier unit is cut off. The main power rectifier unit takes over the power supply of the auxiliary power supply unit.

[0040] The details are as follows:

[0041] See also Figure 1As shown, the present invention provides a low-power standby control circuit adapted to new and old charging piles, including a main circuit control unit 100, a pre-charge control unit 200, an EMC filter unit 300, a main power rectifier unit 400, a zero-power control unit 500, a low-power control unit 600, an auxiliary power supply unit 700 and an auxiliary rectifier unit 800. The main circuit control unit 100 is pre-placed at the input port to control the switch of the EMC filter unit 300. The zero-power control unit 500 and the low-power control unit 600 are arranged in series to control the on and off of the auxiliary rectifier unit 800. The auxiliary power supply unit 700 provides input for the auxiliary rectifier unit 800 in standby mode.

[0042] In standby mode, the main circuit control unit 100 is disconnected and the EMC filter unit 300 is cut off to eliminate reactive loss. If the charging pile provides a 12V drive signal, the zero-power control unit 500 is disconnected, and the module is completely cut off from the mains to achieve zero active power loss. If the charging pile does not provide a 12V drive signal, the zero-power control unit 500 is closed, the auxiliary rectifier unit 800 works, and the module enters a low active power loss mode. When the power is turned on, the pre-charge control unit 200 is first energized to pre-charge the capacitor of the EMC filter unit 300 through the pre-charge resistor. After the pre-charge is completed, the main circuit control unit 100 is energized to connect the main power rectifier unit 400. After the main circuit is connected, the low-power control unit 600 is disconnected, and the auxiliary rectifier unit 800 is cut off. The main power rectifier unit 400 takes over the power supply of the auxiliary power supply unit 700.

[0043] In order to better realize the on-off control of the mains and the main power circuit, the main circuit control unit 100 receives the control signal output by the DSP, and controls the disconnection and connection of the mains and the main power circuit by controlling the conduction and disconnection of the non-magnetic power relay JK1, the non-magnetic power relay JK2 and the non-magnetic power relay JK3;

[0044] The non-magnetic latching relay is driven by an electromagnetic coil, with an activation / release time of less than 10ms. Compared with the magnetic latching relay (operation time of 20-30ms), it responds faster and is suitable for safety scenarios that require rapid disconnection of the main circuit. Each phase of the mains power is controlled by an independent relay (JK1 / JK2 / JK3). The failure of any relay does not affect the disconnection of other phases. Compared with the single-phase master control solution, the safety is improved by three times. The independent control of the three phases can prevent the impact of sudden load changes in one phase on other phases. For example, during startup pre-charging, the three-phase relays are time-sharingly activated (at intervals of 5-10ms) to reduce the current superposition impact caused by simultaneous activation.

[0045] The main circuit control unit is disconnected in standby mode, completely isolating the EMC filter unit 300 (including the X capacitor and the common mode inductor) from the mains, thereby eliminating reactive power loss of the X capacitor under AC input.

[0046] In order to better reduce the inrush current, the pre-charge control unit 200 uses non-magnetic latching normally open low-power relays JK8 and JK9 and pre-charge resistors R3 and R4 to pre-charge the capacitor of the EMC filter unit 300 before the non-magnetic power relay JK2 and the non-magnetic power relay JK3 are energized;

[0047] After the DSP outputs the power-on command, it first activates the pre-charge control unit (JK8-JK9), pre-charging the EMC filter capacitor for 500ms through the pre-charge resistor (R3-R4), raising the capacitor voltage to over 90% of the rated value. The main circuit relay (JK1-JK3) is then closed. This process reduces the inrush current from 200A to below 30A, extending the life of the relay contacts by five times.

[0048] The DSP detects the bus voltage (the voltage across CD1-CD2) to confirm that the pre-charging is complete before outputting a stable drive signal to the main circuit relay to avoid false closure or contact jitter due to voltage fluctuations.

[0049] In order to better suppress electromagnetic interference, Figure 2 As shown, the EMC filter unit 300 includes a common mode inductor L4;

[0050] The upper left end of the common-mode inductor L4 is connected to one end of the capacitor CX2, and is connected in parallel to one end of the capacitor CY3 and one end of the capacitor CX1. The left middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX2 and one end of the CX3, and is connected in parallel to one end of the capacitor CY2. The lower left end of the common-mode inductor L4 is connected to the other end of the capacitor CX3, and is connected in parallel to the other end of the capacitor CX1 and one end of the capacitor CY1.

[0051] The upper right end of the common-mode inductor L4 is connected to one end of the capacitor CX5, and is connected to one end of the capacitor CY4 and one end of CX4. The right middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX5 and one end of CX6, and is connected to one end of the capacitor CY5. The lower right end of the common-mode inductor L4 is connected to the other end of the capacitor CX6, and is connected to the other end of the capacitor CX4 and one end of the capacitor CY6.

[0052] In this circuit, the common-mode inductor L4 is two sets of coils wound bidirectionally on the same magnetic core, with the same number of turns and opposite winding directions. When the common-mode interference current passes through, the magnetic fields generated by the two sets of coils are superimposed in the same direction, the saturation inductance of the magnetic core increases, and the common-mode current is suppressed; when the differential-mode interference current passes through, the magnetic fields are reversely offset, the inductance is small, and the normal current is not affected.

[0053] When the common-mode interference current flows through the common-mode inductor L4, the superposition of the magnetic field generates high impedance, forcing the current to flow through the Y capacitors (CY1-CY6) into the ground, attenuating the common-mode interference voltage (for example, from 1000mV to below 100mV);

[0054] The differential-mode interference current (L→N) has low impedance when flowing through the common-mode inductor and needs to be short-circuited to the other phase line through X capacitors (CX1-CX6) to form a low-resistance path (for example, the capacitive reactance of a 10nFX capacitor to 1MHz interference is approximately 1.6kΩ) to prevent the interference from entering the main power rectifier unit 400.

[0055] In standby mode, the main power rectifier unit 400 is disconnected, the EMC filter unit 300 is disconnected from the mains, and the X capacitor is no longer excited, eliminating 300-600Var reactive power loss (in traditional solutions, X capacitors continue to work and generate reactive power loss);

[0056] During startup, the pre-charge control unit 200 charges the X capacitors (CX1-CX6) and busbar electrolytic capacitors through resistors to prevent the residual charge in the X capacitors from being superimposed on the mains power when the main relay is energized, generating an inrush current. After pre-charging, the X capacitor voltage gradually rises, evenly distributing the withstand voltage stress of the common-mode inductor L4 and the Y capacitor, protecting the EMC components from damage due to transient overvoltages.

[0057] In order to better convert AC power into DC power, the main power rectifier unit 400 includes PFC inductor L1, PFC inductor L2 and PFC inductor L3;

[0058] One end of the PFC inductor L1 is connected to the anode of diode D1, in parallel with the cathode of diode D4. One end of the PFC inductor L2 is connected to the anode of diode D2, in parallel with the cathode of diode D5. One end of the PFC inductor L3 is connected to the anode of diode D3, in parallel with the cathode of diode D6. The cathode of diode D3 is connected to the cathode of diode D1 and the cathode of diode D2, and to one end of capacitor CD1. The other end of capacitor CD1 is connected to one end of capacitor CD2. The other end of capacitor CD2 is connected to the anode of diode D4 and the anode of diode D5, and to the anode of diode D6.

[0059] In this circuit, the three-phase AC power has a phase difference of 120°. At any moment, two diodes in the rectifier bridge are turned on (one upper bridge and one lower bridge), converting the AC power of the corresponding phase into DC power. When the voltage of inductor L1 is higher than that of inductor L2 and inductor L3, diode D1 (upper bridge) and diode D5 (lower bridge) are turned on, and the current forms a loop through inductor L1 → diode D1 → DC bus → load → DC bus → diode D5 → inductor L2.

[0060] By utilizing the energy storage characteristics of inductor L4, the rising edge of the current is delayed, making the input current waveform close to a sine wave and in phase with the voltage, suppressing high-order harmonics (such as the 5th and 7th harmonics), and reducing the total harmonic distortion (THD) to below 10%, in compliance with the IEEE519 standard.

[0061] In order to better control the input power of the auxiliary rectifier unit 800, the zero-power control unit 500 includes a non-magnetic latching normally closed relay JK4 and a non-magnetic latching normally closed relay JK6. The 12V drive signal provided by the charging pile controls the on and off of relays JK4 and JK6 to control the input power of the auxiliary rectifier unit 800;

[0062] When no drive signal is applied to the non-magnetic latching normally closed relay JK4 and the non-magnetic latching normally closed relay JK6, the contacts are in the closed state (normally closed), connecting the AC input circuit of the auxiliary rectifier unit 800. When the charging pile applies a 12V DC voltage to the relay coil, the electromagnetic coil generates a magnetic field, pushing the contacts open, and cutting off the connection between the auxiliary rectifier unit 800 and the mains.

[0063] When the charging pile outputs a continuous 12V signal to the zero-power control unit, the JK4 and JK6 relays are disconnected, the auxiliary rectifier unit 800 cannot obtain AC input, the auxiliary power supply stops working, and the module is completely isolated from the mains, achieving "zero active power loss". When the charging pile has no 12V signal, the JK4 and JK6 relays remain normally closed, the auxiliary rectifier unit 800 is connected to the mains, providing a low-load input (power consumption < 0.8W) for the auxiliary power supply, and the module enters the "low active power + zero reactive power" low-power mode, which is compatible with old charging piles;

[0064] The zero-power control unit 500 is connected in series in the input circuit of the auxiliary rectifier unit 800. When its relay is disconnected, the power supply can be cut off regardless of whether the internal components of the auxiliary rectifier unit 800 are normal. After powering on, the DSP inside the module controls the low-power control unit 600 (JK5, JK7) to disconnect. Even if the zero-power control unit 500 remains closed due to a fault, the auxiliary rectifier unit 800 will be bypassed to avoid damage to it due to the high load of the main power circuit.

[0065] In order to better switch the power consumption mode, the low-power control unit 600 includes a non-magnetic latching normally closed relay JK5 and a non-magnetic latching normally closed relay JK7, which are controlled by the DSP chip. In standby mode, relays JK5 and JK7 are normally closed. The power consumption mode is switched according to the state of the zero-power control unit 500. After power on, relays JK5 and JK7 are disconnected to cut off the auxiliary rectifier unit 800.

[0066] When there is no DSP control signal, the contacts of the non-magnetic latching normally closed relays (JK5, JK7) remain closed, connecting the output circuit of the auxiliary rectifier unit 800. When the DSP outputs a control signal, the relay coil is energized and the contacts are opened, cutting off the connection between the auxiliary rectifier unit 800 and the auxiliary power supply unit 700.

[0067] The low-power control unit 600 (JK5, JK7) and the zero-power control unit 500 (JK4, JK6) are connected in series in the loop of the auxiliary rectifier unit 800, forming a "dual-switch" interlocking mechanism:

[0068] The zero-power control unit 500 is disconnected → regardless of the state of the low-power control unit 600, the auxiliary rectifier unit 800 is powered off → zero-power mode;

[0069] The zero-power control unit 500 is closed and the low-power control unit 600 is closed → the auxiliary rectifier unit 800 works → low-power mode;

[0070] After startup, the low power control unit 600 is disconnected → the auxiliary rectifier unit 800 is bypassed → the main power circuit is powered.

[0071] In order to better achieve low-power standby and zero-power switching, the auxiliary rectifier unit 800 includes a diode D7, a diode D8, a diode D9 and a diode D10;

[0072] The cathode of diode D7 is connected to the cathode of diode D8 and to one end of resistor R1. The other end of resistor R1 is connected to one end of capacitor CD3. The other end of capacitor CD3 is connected to one end of capacitor CD4. The other end of capacitor CD4 is connected to one end of resistor R2. The other end of resistor R2 is connected to the anode of diode D9 and to the anode of diode D10. The cathode of diode D9 is connected to the anode of diode D7. The cathode of diode D10 is connected to the anode of diode D8.

[0073] In this circuit, mains power (380V AC) enters the bridge rectifier circuit (D7-D10) through current-limiting resistors (R1-R2), converting the AC power into pulsating DC. Current-limiting resistors (R1-R2) precharge the electrolytic capacitors (CD3-CD4). The pulsating DC is filtered by the electrolytic capacitors (CD3-CD4) to output a smooth 310V DC bus voltage, providing a low-load input for the auxiliary power supply unit 700 and maintaining the operation of the DSP basic circuit.

[0074] Zero power consumption control unit 500 (JK4, JK6) is disconnected → AC input of auxiliary rectifier unit 800 is cut off → no rectifier output → auxiliary power supply is powered off → active power loss is 0W;

[0075] The zero-power control unit 500 is closed → the auxiliary rectifier unit 800 works → outputs 310V DC → the auxiliary power supply outputs 12V / 0.1A → the module maintains low-power communication.

[0076] In order to better reduce power consumption, the zero-power control unit 500 and the low-power control unit 600 both use low-power relays with a driving power less than 0.5W, which are adapted to the charging pile control power supply design;

[0077] Traditional magnetic latching relay solutions require the charging pile auxiliary power supply to provide more than 3W of driving power, while the low-power relay solution consumes only less than 0.5W, reducing the auxiliary power supply load by 80%. It is particularly suitable for charging piles with small-capacity auxiliary power supplies (such as 12V / 1A) to avoid auxiliary power supply overload protection.

[0078] The low-power relay has a small driving current and low coil heat generation (temperature rise ≤ 20°C), which avoids insulation aging caused by long-term power-on and extends the relay life to more than 1 million times.

[0079] In order to better avoid overload, the auxiliary rectifier unit 800 adopts a time-sharing multiplexing strategy. When in standby mode, the auxiliary rectifier unit 800 provides low-load input. After startup, it switches to the main power rectifier unit 400 to avoid overload of the auxiliary rectifier unit 800.

[0080] In standby mode, the zero-power control unit 500 (JK4, JK6) is closed and the low-power control unit 600 (JK5, JK7) is normally closed. The AC input of the auxiliary rectifier unit 800 is connected. After rectification by diodes D7-D10, current limiting by resistors R1-R2, and filtering by capacitors CD3-CD4, a 310V DC bus voltage is output. This provides a low-load input (≤1W) for the auxiliary power supply unit 700, maintaining the operation of basic circuits such as the DSP and communication module.

[0081] After power-on, the pre-charge control unit 200 completes the pre-charge of the EMC filter capacitor → the relay is energized to connect the main power rectifier unit 400 → the DSP controls the low-power control unit 600 (JK5, JK7) to disconnect → the output circuit of the auxiliary rectifier unit 800 is cut off, and the main power rectifier unit 400 provides high-load input for the auxiliary power supply.

[0082] like Figure 3As shown, the main circuit control unit 100 cooperates with the pre-charge control unit 200 to control the on-off of the main power circuit, and cooperates with the EMC filter unit 300 and the main power rectifier unit 400 to achieve efficient transmission of electric energy. The EMC filter unit 300 filters the main power interference, ensures the power quality, and provides clean input for subsequent units. The main power rectifier unit 400 converts AC power into DC power and provides high-power DC output for the core link of charging. The auxiliary power supply unit 700 provides a stable low-voltage power supply for each control circuit in the module (such as DSP, relay drive). The DSP main control unit serves as the "brain" of the module, collecting signals, performing calculations, and coordinating the various units. Meta-timing and mode switching (zero power consumption / low power consumption), the auxiliary rectifier unit 800 provides low-load input when in standby mode, and switches to the main power rectifier unit 400 after startup to avoid self-overload and realize time-sharing multiplexing. The zero-power control unit 500 contains a non-magnetic holding normally closed relay (JK4 / JK6), which controls the input power of the auxiliary rectifier unit 800 through the 12V driving signal of the charging pile to trigger the "zero power consumption" mode. The low-power control unit 600 contains a non-magnetic holding normally closed relay (JK5 / JK7), which is controlled by the DSP. It remains normally closed to maintain low power consumption in standby mode and disconnects the auxiliary rectifier unit 800 after startup to protect the circuit.

[0083] In summary, the working principle of this solution is as follows:

[0084] This low-power standby control module, which is compatible with both new and old charging piles, controls the disconnection of relays JK1, JK2, and JK3 through the main circuit control unit 100, disconnecting the EMC filter unit 300 to achieve zero reactive power loss. Combined with the series design of the zero-power control unit 500 and the low-power control unit 600, it achieves "zero power-low power" dual-mode adaptive switching, is compatible with both new and old charging piles, and uses non-magnetic latching power relays and low-power relays to replace high-cost magnetic latching relays, reducing hardware costs and avoiding the hidden dangers of abnormal resets.

[0085] The pre-charge control unit 200 pre-charges the EMC filter capacitor when the power is turned on, eliminating the impact current when the main relay is energized, thereby extending the life of the relay. In standby mode, the auxiliary rectifier unit 800 provides low-load input, and after power is turned on, it switches to the main power rectifier unit 400, which not only ensures low standby power consumption, but also avoids overload of the auxiliary rectifier unit 800, thereby improving system reliability.

[0086] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A low-power standby control circuit adapted to both new and old charging piles, characterized by: The invention comprises a main circuit control unit (100), a pre-charge control unit (200), an EMC filter unit (300), a main power rectifier unit (400), a zero power consumption control unit (500), a low power consumption control unit (600), an auxiliary power supply unit (700) and an auxiliary rectifier unit (800); the main circuit control unit (100) is pre-placed at an input port to control the switch of the EMC filter unit (300); the zero power consumption control unit (500) and the low power consumption control unit (600) are arranged in series to control the on / off of the auxiliary rectifier unit (800); and the auxiliary power supply unit (700) provides input for the auxiliary rectifier unit (800) when in standby mode; In the standby state, the main circuit control unit (100) is disconnected, and the EMC filter unit (300) is cut off to eliminate reactive power loss. If the charging pile provides a 12V driving signal, the zero power consumption control unit (500) is disconnected, and the module is completely cut off from the mains power to achieve zero active power loss. If the charging pile does not provide a 12V driving signal, the zero power consumption control unit (500) is closed, the auxiliary rectifier unit (800) works, and the module enters a low active power loss mode. When the module is turned on, the pre-charge control unit (200) is first attracted to pre-charge the capacitor of the EMC filter unit (300) through the pre-charge resistor. After the pre-charge is completed, the main circuit control unit (100) is attracted to connect the main power rectifier unit (400). After the main circuit is connected, the low power consumption control unit (600) is disconnected, and the auxiliary rectifier unit (800) is cut off. The main power rectifier unit (400) takes over the power supply of the auxiliary power supply unit (700).

2. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The main circuit control unit (100) receives the control signal output by the DSP and controls the disconnection and connection of the main power circuit by controlling the conduction and disconnection of the non-magnetic power relay JK1, the non-magnetic power relay JK2 and the non-magnetic power relay JK3.

3. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The pre-charge control unit (200) uses non-magnetic latching normally open low-power relays JK8 and JK9 and pre-charge resistors R3 and R4 to pre-charge the capacitance of the EMC filter unit (300) before the non-magnetic power relay JK2 and the non-magnetic power relay JK3 are closed.

4. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The EMC filter unit (300) includes a common mode inductor L4; The upper left end of the common-mode inductor L4 is connected to one end of the capacitor CX2, and is connected in parallel to one end of the capacitor CY3 and one end of the capacitor CX1. The left middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX2 and one end of the capacitor CX3, and is connected in parallel to one end of the capacitor CY2. The lower left end of the common-mode inductor L4 is connected to the other end of the capacitor CX3, and is connected in parallel to the other end of the capacitor CX1 and one end of the capacitor CY1. The upper right end of the common-mode inductor L4 is connected to one end of the capacitor CX5, and is connected to one end of the capacitor CY4 and one end of CX4. The right middle end of the common-mode inductor L4 is connected to the other end of the capacitor CX5 and one end of CX6, and is connected to one end of the capacitor CY5. The lower right end of the common-mode inductor L4 is connected to the other end of the capacitor CX6, and is connected to the other end of the capacitor CX4 and one end of the capacitor CY6.

5. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The main power rectifier unit (400) comprises a PFC inductor L1, a PFC inductor L2 and a PFC inductor L3; One end of the PFC inductor L1 is connected to the anode of the diode D1 and to the cathode of the diode D4. One end of the PFC inductor L2 is connected to the anode of the diode D2 and to the cathode of the diode D5. One end of the PFC inductor L3 is connected to the anode of the diode D3 and to the cathode of the diode D6. The cathode of the diode D3 is connected to the cathode of the diode D1 and the cathode of the diode D2, and to one end of the capacitor CD1. The other end of the capacitor CD1 is connected to one end of the capacitor CD2. The other end of the capacitor CD2 is connected to the anode of the diode D4 and the anode of the diode D5, and to the anode of the diode D6.

6. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The zero-power control unit (500) comprises a non-magnetic latching normally closed relay JK4 and a non-magnetic latching normally closed relay JK6, and controls the on and off of relays JK4 and JK6 through a 12V driving signal provided by the charging pile, thereby controlling the input power supply of the auxiliary rectifier unit (800).

7. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The low-power control unit (600) comprises a non-magnetic latching normally closed relay JK5 and a non-magnetic latching normally closed relay JK7, which are controlled by a DSP chip. In standby mode, relays JK5 and JK7 are normally closed. The power consumption mode is switched according to the state of the zero-power control unit (500). After power-on, relays JK5 and JK7 are disconnected to cut off the auxiliary rectifier unit (800).

8. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The auxiliary rectifying unit (800) comprises a diode D7, a diode D8, a diode D9 and a diode D10; The cathode of the diode D7 is connected to the cathode of the diode D8 and is connected in parallel to one end of the resistor R1. The other end of the resistor R1 is connected to one end of the capacitor CD3. The other end of the capacitor CD3 is connected to one end of the capacitor CD4. The other end of the capacitor CD4 is connected to one end of the resistor R2. The other end of the resistor R2 is connected to the anode of the diode D9 and is connected in parallel to the anode of the diode D10. The cathode of the diode D9 is connected to the anode of the diode D7. The cathode of the diode D10 is connected to the anode of the diode D8.

9. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The zero-power control unit (500) and the low-power control unit (600) both use low-power relays, with a driving power less than 0.5W, and are adapted to the charging pile control power supply design.

10. The low-power standby control module adapted to both new and old charging piles according to claim 1, characterized in that: The auxiliary rectifier unit (800) adopts a time-division multiplexing strategy. When in standby mode, the auxiliary rectifier unit (800) provides a low-load input. After startup, the auxiliary rectifier unit (800) switches to the main power rectifier unit (400) to avoid overloading of the auxiliary rectifier unit (800).

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