CN203984082U - The fast switch circuit of a kind of UPS - Google Patents

Abstract

The utility model relates to the fast switch circuit of a kind of UPS, in addition, on each loop, there are NO and the series connection of NC node of 2 relays, on the loop that needs to disconnect, there are 2 nodes to move simultaneously, avoid because of the contact endurance that draws electric arc influence relay between the action contact, a contact of a relay, in some frequent occasions of switching, the useful life that can greatly improve commutation circuit.

Description

A Fast Switching Circuit of UPS

technical field

The utility model relates to a fast switching circuit of UPS.

Background technique

At present, in the switching circuit of small UPS (5kW and below power level), in consideration of cost and other reasons, fast relays are generally used as switching elements. Generally, a relay or two relays are used to form a switching circuit. It is easiest to use a relay with a changeover contact to form a switching circuit, but the switching time of one party does not meet the national standard requirements, and because the normally open and normally closed nodes are in a small relay, the distance between the contacts is very close, and it is easy to switch Arcing has an impact on the life of the contacts of the relay. Using two relays with changeover contacts for switching can meet the switching time requirements of both parties, but it will inevitably cause a short circuit of the two outputs of about 10ms.

Utility model content

The purpose of the utility model is to provide a fast switching circuit of UPS to solve the problems of slow switching speed or output short circuit of the existing switching circuit.

In order to achieve the above object, the scheme of the present utility model includes:

A fast switching circuit for UPS, at least two relays are connected in series on the bypass line, one is a bypass normally open relay and the other is a bypass normally closed relay, and two relays are connected in series on the inverter output line, one is The inverter normally open relay, the other is an inverter normally closed relay; the bypass output line and the inverter output line are shorted on the output side; the bypass normally closed relay and the inverter normally closed relay are powered on by the auxiliary power supply of the UPS When the bypass input is normal, the bypass normally open relay acts; when the inverter output is normal, the inverter normally open relay acts.

The bypass normally open relay, bypass normally closed relay, inverter normally open relay, and inverter normally closed relay have 2-3 relays of the same type and model in parallel connection on each relay.

A switching control method, comprising the steps of:

When the bypass input line output is required, release the bypass normally closed relay; when the inverter output is required, release the inverter normally closed relay;

When switching from inverter to bypass normally, the inverter normally open relay and bypass normally closed relay are released at the same time, and the inverter normally closed relay is activated; after a certain time delay, the inverter normally open relay is activated to switch from bypass to inverter Be ready for the switch of change;

When switching from bypass to inverter normally, release the bypass normally open relay and inverter normally closed relay at the same time, and activate the bypass normally closed relay; Prepare for road switching;

Abnormal switching from inverter to bypass, release the inverter normally open relay, bypass normally closed relay at the same time, and activate the inverter normally closed relay;

For abnormal switching from bypass to inverter, release the bypass normally open relay and inverter normally closed relay at the same time, and activate the bypass normally closed relay.

With the structure and operation of the utility model, the switching time is only related to the release time of the relay. Because the release time of small relays is generally more than twice as fast as the action time, it is possible to use ordinary relays with action/release times of 15ms/5ms to complete fast switching within 5ms.

In addition, there are two NO and NC nodes of relays connected in series on each circuit, and two nodes on the circuit that needs to be disconnected act at the same time, which avoids the influence of the electric arc between contacts caused by one contact action of one relay. Contact life, in some frequent switching occasions, can greatly improve the service life of the switching circuit.

Description of drawings

Fig. 1 is the circuit schematic diagram of the present embodiment of the utility model;

Figure 2 is a schematic diagram of bypass output;

Fig. 3 is the principle diagram when inverting the output;

Figure 4 is a signal diagram of the normal switching relay action from inverter to bypass;

Fig. 5 is a normal switching relay action signal diagram from bypass to inverter;

Fig. 6 is the action signal diagram of the fault switching relay from inverter to bypass;

Fig. 7 is a diagram of the action signal of the fault switching relay from the bypass to the inverter.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Set two relays in series on the bypass line, one is a bypass normally open relay and the other is a bypass normally closed relay, and two relays are connected in series on the inverter output line, one is an inverter normally open relay and the other is a bypass relay. The inverter normally closed relay; the bypass output line and the inverter output line are shorted on the output side. Bypass refers to the bypass input circuit, and inverter refers to the inverter output circuit.

1. The bypass normally closed relay and the inverter normally closed relay operate after the auxiliary power supply of the UPS is powered on. When the bypass input is normal, the bypass normally open relay acts; when the inverter output is normal, the inverter normally open relay also acts. When the bypass input line output is required, release the bypass normally closed relay; when the inverter output is required, release the inverter normally closed relay.

2. When switching from inverter to bypass, release the inverter normally open relay and bypass normally closed relay at the same time, and act as the inverter normally closed relay. Due to the fast action of the release relay, the output can be quickly switched to the bypass. After a certain time delay, the inverter normally open relay will be activated to prepare for the switch from bypass to inverter.

3. When switching from bypass to inverter normally, release the bypass normally open relay and inverter normally closed relay at the same time, and activate the bypass normally closed relay. Due to the fast action of the release relay, the output can be quickly switched to the inverter output. After a certain time delay, the bypass normally open relay is activated again to prepare for the switching from inverter to bypass.

4. The abnormal switching from inverter to bypass is currently the output of the inverter. If the inverter fails, it must be switched to the bypass output. At the same time, the inverter normally open relay and the bypass normally closed relay are released. Close the relay.

5. Abnormal switching from bypass to inverter. Currently, it is bypass output. If bypass fails, it must switch to inverter output. At the same time, release the bypass normally open relay and inverter normally closed relay, and the action bypass normally closed relay.

Specifically, as shown in the embodiment shown in Figure 1, a fast switching circuit for a small UPS, the bypass L line and the inverter L line are short-circuited at the output side, and the bypass normally open relay and the bypass normally closed relay are respectively denoted as BK1, BK2. The inverter normally open relay and the inverter normally closed relay are respectively marked as IK1 and IK2. The bypass N and inverter N wires are directly shorted. The front and rear positions of the two contacts BK1, BK2 (IK1, IK2) on the circuit can be interchanged.

The working process is:

1. After the auxiliary power supply of the UPS is powered on, both BK2 and IK2 operate without output. Detect whether the bypass input voltage is normal, if normal, BK1 acts, detect whether the inverter output is normal, if normal, IK1 also acts. At this time, if the inverter output is required, release IK2, and if the bypass input and output are required, release BK2. Figure 2 is a schematic diagram of bypass output, and Figure 3 is a schematic diagram of inverter output.

2. The normal switch from inverter to bypass is currently the output of the inverter. If you want to switch to bypass output, release IK1 and BK2 at the same time and act on IK2. Because both IK1 and BK2 are released, the action speed is fast and the output is fast When switching to the bypass, IK2 will act slowly, and after 20ms, it will act on IK1 to prepare for the switch from the bypass to the inverter. Fig. 4 is a diagram of relay action signals from inverter to bypass switching to normal switching. In Figure 4 to Figure 7, the high level is action, and the low level is release.

3. The normal switching from bypass to inverter is currently bypass output. If you want to switch to inverter output, release BK1 and IK2 at the same time, and act on BK2, because both BK1 and IK2 are released, the action speed is fast, and the output is switched quickly to the inverter output. BK2 moves slowly, after 20ms, then moves BK1 to prepare for switching from inverter to bypass. Figure 5 is a diagram of relay action signals from bypass to inverter switching.

4. The abnormal switching from inverter to bypass is currently the output of the inverter. If the inverter fails, it must be switched to the bypass output. At the same time, IK1 and BK2 are released, and IK2 is activated. Because both IK1 and BK2 are released, so The action speed is fast, the output is quickly switched to the bypass, and the IK2 action is slower. Figure 6 shows the relay action signal diagram for abnormal switching from inverter to bypass.

5. The abnormal switch from bypass to inverter is currently the bypass output. If the bypass fails, it has to switch to the inverter output, release BK1 and IK2 at the same time, and act on BK2, because both BK1 and IK2 are released, and the action speed Fast, the output is quickly switched to the inverter output, and BK2 moves slower. Fig. 7 is a relay action signal diagram for abnormal switching from bypass to inverter.

It can be seen from the above four switching situations that disconnection and input are both a quick release process of the relay. The guaranteed switching time is the release time of the relay. Depending on the selected relay, the guaranteed switching time is generally 2-4ms. For example, the finder relay 40.61.7024 selected in the illustration can guarantee a switching time of 3ms.

As other implementations, the application power range of the switching circuit can be expanded by connecting relays in parallel. For example, three identical relays are connected in parallel at each relay position, which can be applied to a 10kW UPS. However, due to the problem of current sharing and the deviation of operating time, it is generally advisable not to exceed 3-4 in parallel.

Specific implementations have been given above, but the utility model is not limited to the described implementations. The basic idea of the present utility model lies in the above-mentioned basic scheme. For those of ordinary skill in the art, according to the teaching of the present utility model, it does not need to spend creative labor to design various deformation models, formulas and parameters. Changes, modifications, replacements and modifications to the embodiments without departing from the principle and spirit of the present utility model still fall within the protection scope of the present utility model.

Claims (2)

1. the fast switch circuit of a UPS, it is characterized in that, in by-pass line, string is established at least two relays, one is bypass normally opened relay, another is bypass normally closed relay, on inversion outlet line, string is established two relays, and one is inversion normally opened relay, and another is inversion normally closed relay; Bypass outlet line and inversion outlet line are at outlet side short circuit; Described bypass normally closed relay, inversion normally closed relay move after the accessory power supply of UPS powers on; When bypass input is normal, the action of bypass normally opened relay; Inverter is exported when normal, the action of inversion normally opened relay.

2. the fast switch circuit of a kind of UPS according to claim 1, it is characterized in that, described bypass normally opened relay, bypass normally closed relay, inversion normally opened relay, inversion normally closed relay, be all parallel with the relay of 2-3 same model of the same type on each relay.