Surge discharge circuit and power supply system

Abstract

The utility model provides a kind of surge discharge circuit and power supply system, it is related to power supply technical field.The surge discharge circuit includes: at least one relay, surge protection unit and voltage conversion unit;At least one relay is connected in series between power supply and ground with surge protection unit;Power supply supplies power for each relay by voltage conversion unit;When power supply starts, each relay is turned on.In the present application, relay is automatically turned on after power supply starts, and when there is surge, it is discharged to ground through surge protection unit, effectively protecting power supply.Due to the setting of relay, the voltage of the circuit is effectively improved by the voltage division of the relay.

Description

Technical Field

[0001] This utility model relates to the field of power supply technology, and in particular to a surge discharge circuit and power supply system. Background Technology

[0002] A surge, also known as a voltage spike, is, as the name suggests, a momentary overvoltage exceeding the normal operating voltage. Essentially, a surge is a violent pulse that occurs within a fraction of a second. Potential causes of surges include heavy equipment, short circuits, power switching, or large motors. Products containing surge protection devices can effectively absorb sudden, massive energy surges, protecting connected equipment from damage.

[0003] The power supply of the distribution network is required to withstand a differential surge level of 4, which means that a 4kV surge signal is applied between the input terminal and the chassis ground. Therefore, a surge isolation device must be installed at the output terminal of the power supply to prevent surges from damaging the power supply.

[0004] In the existing technology, surge blocking devices are usually simply built using surge discharge components. The circuit is simple and the cost is low, but it cannot completely discharge high surge signals, which leads to abnormal power supply in the distribution network and fails the withstand voltage test. Utility Model Content

[0005] This utility model provides a surge discharge circuit and power supply system to solve the problem that the withstand voltage of the surge blocking device in the prior art is not high enough to meet the needs of practical applications.

[0006] In a first aspect, the present invention provides a surge discharge circuit, comprising: at least one relay, a surge protection unit, and a voltage conversion unit; At least one relay is connected in series with the surge protection unit between the power supply and the ground; The power supply provides power to each relay through a voltage conversion unit; when the power supply is started, each relay is turned on.

[0007] Optionally, the surge protection unit includes: at least one surge discharge subunit; At least one surge discharge subunit is connected in series between the two ends of the surge protection unit.

[0008] Optionally, the number of surge discharge sub-units is two; the first surge discharge sub-unit includes at least one varistor connected in parallel; the second surge discharge sub-unit includes at least one gas discharge tube connected in parallel.

[0009] Optionally, the first surge discharge subunit includes: a varistor; The second surge discharge subunit includes a gas discharge tube.

[0010] Optionally, the voltage conversion unit includes: a voltage conversion subunit and a current-limiting resistor; wherein, the voltage conversion subunit is located inside the power supply. The input terminal of the voltage conversion subunit is connected to the power supply, and the output terminal of the voltage conversion subunit supplies power to each relay through a current-limiting resistor.

[0011] Optionally, the relay is a normally open contact relay.

[0012] Secondly, this utility model provides a power supply system, including: a power supply and three surge discharge circuits as provided in any of the above embodiments; wherein the power supply is a three-phase AC power supply; The three surge discharge circuits are connected between the three-phase output terminals of the power supply and the ground, respectively.

[0013] Thirdly, this utility model provides a power supply system, including: a power supply, three surge discharge devices, and a surge discharge circuit as provided in any of the above embodiments; wherein the power supply is a three-phase AC power supply; The surge discharge circuit is connected between any one phase output terminal of the power supply and the ground; A surge discharge device is connected between each pair of the three-phase output terminals of the power supply.

[0014] Optionally, the surge discharge device is a varistor.

[0015] Optionally, the power supply system also includes: three capacitors; The three capacitors are connected between the three-phase output terminals of the power supply and the ground, respectively.

[0016] This utility model provides a surge discharge circuit and power supply system. The surge discharge circuit includes: at least one relay, a surge protection unit, and a voltage conversion unit; at least one relay and the surge protection unit are connected in series between the power supply and ground; the power supply supplies power to each relay through the voltage conversion unit; when the power supply is started, each relay is turned on. When the power supply is not started, the relays are off, and the withstand voltage across the relays is relatively high; when the power supply is started, the relays automatically turn on, and the withstand voltage of the power supply to ground is the sum of the withstand voltages of each relay and the surge protection unit, with the power supply having a higher withstand voltage rating to ground. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a surge discharge circuit provided in an embodiment of the present invention; Figure 2 This is a partial structural schematic diagram of the power supply system provided in an embodiment of this utility model. Detailed Implementation

[0018] To enable those skilled in the art to better understand this solution, the technical solutions in the embodiments of this solution will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this solution, not all of them. Based on the embodiments of this solution, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this solution.

[0019] The term "comprising" and any other variations thereof in the specification, claims, and accompanying drawings of this invention mean "including but not limited to," and are intended to cover a non-exclusive inclusion, not limited to the examples listed herein. Furthermore, the terms "first" and "second," etc., are used to distinguish different objects, not to describe a specific order.

[0020] The implementation of this utility model will be described in detail below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a surge discharge circuit provided for an embodiment of the present invention. (Refer to...) Figure 1 The surge discharge circuit includes: at least one relay (JK1, JK2), surge protection unit 1, and voltage conversion unit; At least one relay (JK1, JK2) is connected in series with surge protection unit 1 between the power supply and ground (FG); The power supply supplies power to each relay (JK1, JK2) through a voltage conversion unit; when the power supply starts, each relay (JK1, JK2) is turned on.

[0021] When the power supply is not started, there is no output, the voltage conversion unit has no input voltage, and therefore cannot supply power to the relay coil. The relay is disconnected, and the surge protection circuit is not connected to the circuit.

[0022] When the power supply starts, it supplies power to the relay through the voltage conversion unit. The relay coil is energized and conducts, making the path from the power supply to the relay to the surge protection unit 1 to the ground (FG) completely open.

[0023] When a surge occurs, the surge is transmitted through the relay to surge protection unit 1. After the voltage of surge protection unit 1 exceeds the threshold, it conducts and quickly discharges to the ground, thus completing the discharge of the surge and greatly reducing the interference of the surge on the power supply.

[0024] When the relay is turned on, the withstand voltage of the power supply to ground is the sum of the withstand voltage values ​​of each relay (JK1, JK2) and surge protection unit 1, which effectively improves the withstand voltage value of the power supply output, making the surge discharge circuit applicable to high withstand voltage level application scenarios and improving the applicability of the circuit.

[0025] Meanwhile, the relay's "power-off disconnect" design completely cuts off the surge protection path when the equipment is not in operation, eliminating the risk of false triggering in non-operating states and ensuring the stability of the circuit when idle. It also reduces unnecessary leakage current losses, extending the service life of surge protection unit 1. This application precisely focuses protection resources on the critical stages of equipment operation, ensuring surge protection in core scenarios while avoiding resource waste and reducing the probability of equipment damage caused by surges.

[0026] It should be noted that the number of relays can be determined based on the voltage withstand requirements of the power supply. The more relays there are, the higher the voltage withstand value; the fewer relays there are, the lower the voltage withstand value.

[0027] In one possible implementation, refer to Figure 1 The surge protection unit 1 includes at least one surge discharge subunit 11; At least one surge discharge subunit 11 is connected in series between the two ends of the surge protection unit 1.

[0028] The withstand voltage of a single surge discharge element is limited. When the surge voltage that may occur in the circuit exceeds the withstand voltage of a single element, multiple surge discharge sub-units 11 can be connected in series to improve the withstand voltage level of the entire surge protection unit 1.

[0029] Each surge discharge subunit 11 can be different and connected in series to achieve tiered discharge.

[0030] For example, when the applied voltage to a gas discharge tube increases to exceed the insulation strength of the gas, the gap between the two electrodes will break down, changing from the original insulating state to a conductive state. After conduction, the voltage between the two electrodes of the discharge tube remains at the residual voltage level determined by the discharge arc. Gas discharge tubes have high insulation resistance, very low parasitic capacitance, strong surge protection capability, and relatively slow response speed, but large current carrying capacity, which can be used to discharge most of the energy of a surge. A varistor is a resistive device with nonlinear current-voltage characteristics, mainly used for voltage clamping when a circuit is subjected to overvoltage, absorbing excess current to protect sensitive components. Varistors have a fast response speed and can be used for further voltage clamping.

[0031] This application connects the two in series. The gas discharge tube first discharges the large surge current, and the varistor then processes the remaining surge energy, clamping the voltage at a lower level, thereby more effectively protecting the downstream circuit.

[0032] In one possible implementation, refer to Figure 1The number of surge discharge subunits 11 can be two; the first surge discharge subunit 11 may include at least one varistor (RV1) connected in parallel; the second surge discharge subunit 11 may include at least one gas discharge tube (FD1) connected in parallel.

[0033] Based on the above, this application sets up two surge discharge subunits 11, one formed by a varistor (RV1) and the other by a gas discharge tube (FD1), to achieve staged discharge. When a surge voltage occurs in the circuit, the varistor in the first surge discharge subunit 11 responds quickly, its resistance value decreases sharply, entering a low-resistance state, quickly clamping the surge voltage to a certain level, initially suppressing transient overvoltage, and preventing the surge voltage from causing instantaneous impact on the downstream circuit. After the varistor initially clamps the surge voltage, if the surge energy is large and the voltage continues to rise to the breakdown voltage of the gas discharge tube, the gas discharge tube in the second surge discharge subunit 11 will conduct, discharging a large amount of surge current to the ground, undertaking the main current discharge task, thereby protecting the circuit from damage by high-energy surges. The varistor and the gas discharge tube work together, playing their roles at different stages, improving the reliability of the protection.

[0034] Meanwhile, connecting multiple varistors or multiple gas discharge tubes in parallel can increase current carrying capacity and reliability. If one varistor / gas discharge tube fails, the others can still work.

[0035] In one possible implementation, the first surge discharge subunit 11 may include a varistor (RV1). The second surge discharge subunit 11 includes a gas discharge tube (FD1).

[0036] When parameters allow, only one varistor and one gas discharge tube can be set, resulting in a simpler circuit and lower cost.

[0037] The varistor / gas discharge tube can be set according to the actual application requirements, and no specific limit is made here.

[0038] In one possible implementation, refer to Figure 1 The voltage conversion unit includes: a voltage conversion subunit and a current-limiting resistor R1; wherein, the voltage conversion subunit is located inside the power supply. The input terminal of the voltage conversion subunit is connected to the power supply, and the output terminal of the voltage conversion subunit supplies power to each relay through the current limiting resistor R1.

[0039] Voltage conversion unit ( Figure 1(Not shown) is used for voltage adaptation. For example, if the power supply is AC and the relay coil's rated voltage is DC, the voltage conversion unit provides a suitable power supply voltage to the relay after rectification and voltage conversion. The current-limiting resistor R1 is used for current protection to prevent overcurrent, thereby extending the relay's service life.

[0040] If the power supply can directly output a suitable supply voltage, the voltage conversion unit can be omitted, and the power supply can directly supply power to each relay through the current limiting resistor R1, simplifying the circuit and reducing costs.

[0041] In one possible implementation, the relay can be a normally open contact relay.

[0042] The normally open contact relay disconnects when power is off and engages when power is on, which can satisfy the relay engaging and conducting action logic when power is supplied for startup.

[0043] correspond Figure 1 The surge discharge circuit shown can withstand a 7kV differential mode surge test, which meets the needs of practical applications.

[0044] Corresponding to the above embodiments, this utility model embodiment also provides a power supply system, including: a power supply and three surge discharge circuits as provided in the above embodiments; wherein, the power supply is a three-phase AC power supply; The three surge discharge circuits are connected between the three-phase output terminals of the power supply and the ground, respectively.

[0045] Since the power supply is a three-phase AC power supply, each phase may be subjected to surges independently. Therefore, this application can set up surge discharge circuits between each phase and the ground to provide surge protection for each phase, thereby improving the reliability of the protection.

[0046] Corresponding to the above embodiments, this utility model embodiment also provides a power supply system, including: a power supply, three surge discharge devices (RV2, RV3, RV4), and a surge discharge circuit as provided in the above embodiments; wherein, the power supply is a three-phase AC power supply; The surge discharge circuit is connected between any one phase output terminal of the power supply and ground (FG); A surge discharge device (RV2, RV3, RV4) is connected between each pair of the three-phase output terminals of the power supply (between A, B, and C).

[0047] refer to Figure 2To reduce costs, this application may also provide a surge discharge circuit in only one phase, and surge discharge devices (RV2, RV3, RV4) between phases to form a surge discharge path. When a phase does not have a surge discharge circuit, its surge can also be connected to the phase with the surge discharge circuit through the surge discharge device to form a discharge path and realize surge discharge to ground.

[0048] Compared to three surge discharge circuits, this application saves two surge discharge circuits and only adds three surge discharge devices. While ensuring protection reliability, the circuit is simpler and the cost is lower.

[0049] In one possible implementation, refer to Figure 2 Surge discharge devices can be varistors.

[0050] This application uses varistors (RV2, RV3, RV4) for phase-to-phase surge protection, which can respond quickly and clamp precisely, complementing the complete surge discharge circuit to ground, thus ensuring comprehensive coverage of ground and phase-to-phase surges in a three-phase system. At the same time, varistors are low-cost, effectively reducing circuit costs.

[0051] In one possible implementation, refer to Figure 2 The power supply system may also include three capacitors (C1, C2, C3). Three capacitors (C1, C2, C3) are connected between the three-phase output terminals (A, B, C) of the power supply and the ground (FG), respectively.

[0052] When high-frequency common-mode interference exists in the system, the surge discharge device has a high impedance to high-frequency signals due to its own parasitic inductance, and the filtering effect is limited. Therefore, this application can also add three capacitors (C1, C2, C3) to the power supply system, which are respectively connected between the three-phase output terminal and the ground (FG) to form a capacitor network, so as to bypass the high-frequency interference directly to the ground (FG) and avoid the interference signal triggering the surge discharge device to malfunction.

[0053] At the same time, capacitors can also slow down the rise rate of surge voltage, which reduces the instantaneous impact of surge on devices and ensures that energy is fully discharged.

[0054] Therefore, this application improves the electromagnetic compatibility of the system by utilizing the high-frequency filtering characteristics of capacitors, reduces the impact loss of protective devices by utilizing surge buffering characteristics, and works in synergy with the original surge discharge circuit to further optimize the surge protection effect of the system, resulting in more comprehensive protection and higher reliability.

[0055] Correspondingly, for the power supply system with three surge discharge circuits, a capacitor network can also be set up to supplement the protection.

[0056] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A surge discharge circuit, characterized in that, include: At least one relay, surge protection unit, and voltage conversion unit; The at least one relay is connected in series with the surge protection unit between the power supply and the ground; The power supply provides power to each of the relays through the voltage conversion unit; when the power supply is started, each of the relays is turned on.

2. The surge discharge circuit as described in claim 1, characterized in that, The surge protection unit includes: at least one surge discharge subunit; The at least one surge discharge subunit is connected in series between the two ends of the surge protection unit.

3. The surge discharge circuit as described in claim 2, characterized in that, The number of surge discharge subunits is two; The first surge discharge subunit includes at least one varistor connected in parallel; the second surge discharge subunit includes at least one gas discharge tube connected in parallel.

4. The surge discharge circuit as described in claim 3, characterized in that, The first surge discharge subunit includes: one of the varistors; The second surge discharge subunit includes: a gas discharge tube.

5. The surge discharge circuit as described in any one of claims 1 to 4, characterized in that, The voltage conversion unit includes: a voltage conversion subunit and a current-limiting resistor; wherein, the voltage conversion subunit is disposed inside the power supply. The input terminal of the voltage conversion subunit is connected to the power supply, and the output terminal of the voltage conversion subunit supplies power to each of the relays through the current limiting resistor.

6. The surge discharge circuit as described in any one of claims 1 to 4, characterized in that, The relay is a normally open contact relay.

7. A power supply system, characterized in that, include: A power supply and three surge discharge circuits as described in any one of claims 1 to 6; wherein the power supply is a three-phase AC power supply; The three surge discharge circuits are respectively connected between the three-phase output terminals of the power supply and the ground.

8. A power supply system, characterized in that, include: The power supply includes a power source, three surge discharge devices, and a surge discharge circuit as described in any one of claims 1 to 6; wherein the power supply is a three-phase AC power source. The surge discharge circuit is connected between any one phase output terminal of the power supply and the ground. Each of the three-phase output terminals of the power supply is connected to a surge discharge device between each pair of the three phase output terminals.

9. The power supply system as described in claim 8, characterized in that, The surge discharge device is a varistor.

10. The power supply system as claimed in claim 8, characterized in that, The power system also includes: three capacitors; The three capacitors are respectively connected between the three-phase output terminals of the power supply and the ground.

Images