CN202872457U - Mechanical-electronic mixing type dual-supply automatic change-over switch - Google Patents

Abstract

The utility model discloses a mechanical-electronic hybrid dual-power automatic transfer switch, which comprises a traditional mechanical dual-power transfer switch composed of two AC contactors of the same specification and a mechanical interlock mechanism, and 2 to 12 two-way An electronic dual-power transfer switch composed of thyristors and their protection and drive units; the control signals for the sequential actions of the AC contactor of the mechanical dual-power transfer switch and the bidirectional thyristors come from the MCU logic unit, and the MCU logic unit includes Power supply part, voltage frequency sampling part, electrical interlock part, alarm and display part. The utility model can solve the technical problems that the traditional dual-power automatic transfer switch cannot have both the manufacturing cost, the short-circuit current resistance performance and the power conversion speed and the like.

Description

Mechatronics Hybrid Dual Power Automatic Transfer Switch

technical field

The utility model relates to a mechanical/electronic hybrid switch.

Background technique

Known dual power supply automatic transfer switch has pure mechanical type and pure electronic type at present. The mechanical automatic transfer switch has the advantages of low cost, high resistance to short-circuit current, and no need for special cooling measures; its disadvantage is that the switching speed is slow, and the fastest power-off time is greater than 50 milliseconds when the power is automatically switched, and the return is automatically switched. The fastest power-off time of 25 milliseconds. The pure electronic automatic transfer switch has the advantages of no contact and no arc, especially the advantage of fast switching speed, and its power-off time can be less than 5 milliseconds; its disadvantages are high cost and low short-circuit current resistance.

Contents of the invention

The purpose of this utility model is to provide a mechanical and electronic hybrid dual-power automatic transfer switch to solve the technical problems of the traditional dual-power automatic transfer switch in terms of cost, short-circuit resistance performance and power conversion speed.

In order to achieve the above object, the adopted technical scheme of the utility model is as follows:

Mechanical and electronic hybrid dual-power automatic transfer switch, which includes a traditional mechanical dual-power transfer switch composed of two AC contactors of the same specification and a mechanical interlock mechanism, and 2 to 12 bidirectional thyristors (the number depends on the number of electrodes) and current level) and its protection and drive unit composed of an electronic dual-power transfer switch; the control signal for the sequential action of the AC contactor of the mechanical dual-power transfer switch and the bidirectional thyristor comes from the MCU logic unit, and the MCU The logic unit includes a power supply part, a voltage frequency sampling part, an electrical interlock part, an alarm and a display part; the A1 and A2 electrodes of the bidirectional thyristor are connected in parallel with the main contacts of the AC contactor, and the main contacts of each phase of the AC contactor Each head is connected in parallel with a group of thyristors according to the load requirements.

The mechanical-electronic hybrid dual-power automatic transfer switch has two-way input power sources, which are independent power sources. The power sources are generator sets, transformers, UPS, and inverters, and phase differences in any electrical angle are allowed.

In the mechanical-electronic hybrid dual-power automatic transfer switch, during stable operation, the thyristor does not carry or switch loads, and only the thyristors switch loads during the conversion period.

In the mechanical-electronic hybrid dual-power automatic transfer switch, the A1 and A2 electrodes of the bidirectional thyristor are connected in parallel with the main contact of the AC contactor after the fuse is connected in series.

The advantages and positive effects of the utility model are that through the ingenious cooperation of the thyristor and the AC contactor, it not only inherits the advantages of high performance and low cost of the mechanical switch against short-circuit current, but also exerts the characteristics of the fast switching speed of the electronic switch to achieve power failure. Power-off time of less than 20 milliseconds on automatic transfer and 5 milliseconds on back-to-auto transfer. The mechanical and electronic hybrid dual-power automatic transfer switch of the utility model has been tested, and fully meets the characteristics of fast conversion speed, stable operation, and strong short-circuit capability. Compared with the existing automatic transfer switch, it is shown in Table 1.

Description of drawings

Fig. 1 is the schematic circuit diagram of the utility model.

Numbers in the figure: ①-input power 1, ②-AC contactor 1, ③-load, ④-AC contactor 2, ⑤-input power 2, ⑥-thyristor 1, ⑦-thyristor 2, ⑧-mechanical interlock.

Detailed ways

The mechanical and electronic hybrid dual-power automatic transfer switch described in the utility model includes a traditional mechanical dual-power transfer switch composed of two AC contactors of the same specification and a mechanical interlock mechanism, and 2 to 12 bidirectional thyristors (quantity Depending on the number of poles and current level) and its protection and drive unit composed of electronic dual power switch. Under the coordination of the MCU logic unit, the AC contactor and the thyristor operate in sequence according to the design sequence to complete reliable high-speed conversion. The MCU logic unit also includes a power supply part, a voltage frequency sampling part, an electrical interlock part, an alarm and a display part. During stable operation, the operating current of the load is provided through one of the AC contactors, and this AC contactor bears the overcurrent and short circuit conditions. During the conversion period, the MCU logic unit sequentially triggers and turns off the thyristor according to the on-off state of the auxiliary contact of the AC contactor, so as to realize high-speed power conversion, and then enter the next stable working period. The A1 and A2 electrodes of the bidirectional thyristor are connected in parallel with the main contacts of the AC contactor (or further protected by series fuses), and the main contacts of each phase of the AC contactor are connected in parallel with a group of thyristors according to the load requirements. The input power supply is a dual-circuit power supply, which can be independent power supplies. The power source can be a generator set, transformer, UPS, inverter, etc., and any electrical angle phase difference is allowed. During stable operation, the thyristor does not carry or switch loads, only during transitions the thyristors switch loads. Thyristors must cooperate with protection circuits and reliable drive circuits and control logic to prevent false triggers from shorting the input power supply.

See Figure 1 for the specific working principle. The input power 1① and input power 2⑤ are sent to the MCU logic unit for judgment after the voltage and frequency sampling circuit. According to the preset automatic conversion mode, the MCU controls an AC contactor in Figure 1 (for example The AC contactor 1②) is closed, so that the load ③ gets the qualified power accepted by the MCU (such as input power 1①). When the input power supply 1① fails or cannot be accepted by the MCU, the MCU controls the AC contactor 1② to disconnect, and at the same time, according to the feedback signal of the AC contactor 1② disconnection, the MCU controls the thyristor ⑦ to turn on, and the AC contactor 2④ accepts at the same time Close command, until the AC contactor 2④ close feedback signal is delivered to the MCU, and the MCU turns off the thyristor ⑦. At this time, the power supply for the load ③ is provided by the input power 2⑤ through the AC contactor 2④. At this point, an automatic conversion from the common power supply to the backup power supply is completed. When the input power supply 1① is restored, after the preset return delay, the MCU controls the AC contactor 2④ to disconnect, and at the same time, according to the feedback signal of the AC contactor 2④ disconnection, the MCU controls the thyristor ⑥ to conduct, and the AC contactor 1② accepts closing at the same time command until the AC contactor 1② closes the feedback signal to the MCU, and the MCU turns off the thyristor ⑥. At this time, the power supply for the load ③ is provided by the input power 1① through the AC contactor 1②. At this point, a return conversion from the backup power supply to the normal power supply is completed.

Table 1:

Claims (4)

1. Mechanical and electronic hybrid dual power automatic transfer switch, characterized in that it includes a traditional mechanical dual power transfer switch composed of two AC contactors of the same specification and a mechanical interlock mechanism, and 2 to 12 bidirectional thyristors The electronic dual-power transfer switch composed of its protection and drive unit; the control signal of the AC contactor of the mechanical dual-power transfer switch and the sequential action of the bidirectional thyristor comes from the MCU logic unit, and the MCU logic unit includes a power supply Part, voltage frequency sampling part, electrical interlock part, alarm and display part; the A1 and A2 electrodes of the bidirectional thyristor are connected in parallel with the main contacts of the AC contactor, and the main contacts of each phase of the AC contactor are connected according to the load A set of thyristors needs to be connected in parallel. 2. According to claim 1, the mechanical and electronic hybrid dual-power automatic transfer switch is characterized in that the input power supply is a dual-circuit power supply, and they are independent power supplies, and the source of power supply is a generator set, a transformer, a UPS, an inverter, And any electrical angle phase difference is allowed. 3. The mechanical-electronic hybrid dual-power automatic transfer switch according to claim 1, characterized in that, during stable operation, the thyristor neither bears nor switches loads, and only switches the thyristors during switching. 4. The mechatronic hybrid dual-power automatic transfer switch according to claim 1, wherein the electrodes A1 and A2 of the bidirectional thyristor are connected in parallel with the main contact of the AC contactor after the fuse is connected in series.

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