CN203896009U - On-line discharge control modular circuit for transformer station storage battery - Google Patents

Abstract

The utility model discloses an on-line discharge control modular circuit for a transformer station storage battery. The on-line discharge control modular circuit comprises a first freewheeling diode, a major loop contactor, a charging contactor, a first direct current bus, and a second direct current bus. The major loop contactor and the charging contactor are connected with the first freewheeling diode in parallel. The positive of the first freewheeling diode is connected to the positive of the transformer station storage battery. The first direct current bus is connected with the negative of the transformer station storage battery. The second direct current bus is connected with the negative of the first freewheeling diode. With the discharge control modular circuit, the discharge process is enabled to be safe, energy-saving and environment-friendly; a storage battery cannot be disengaged from the bus in the discharge process, direct current discharged by the storage battery is converted into alternating current with the frequency and phase identical to that of commercial power, and then the alternating current is fed to an electrical network; and when commercial power or a charging device fails in the storage battery discharge process, discharge of the storage battery is immediately stopped and power supply for the bus is activated.

Description

An online discharge control module circuit for substation storage battery

technical field

The utility model relates to an inverter power supply circuit, in particular to an on-line discharge control module circuit for storage batteries in substations.

Background technique

At present, the power industry generally adopts "load-type" discharge technology to carry out battery check discharge tests to find out the problems existing in battery packs and single cells. In the process of practice, it is found that this method has disadvantages such as complicated operation, heavy workload, and potential safety hazards such as heating.

However, no matter whether electric heating device or active inverter discharge device is used for battery I ₁₀ discharge test, the battery pack must be separated from the DC bus and replaced by a spare battery pack. In the case of only one set of battery packs in the station, during the discharge of the nuclear capacity, once a failure such as mains interruption occurs, the battery packs cannot provide backup power to the DC bus in time, which will bring potential safety hazards.

Utility model content

The purpose of this utility model is to provide an on-line discharge control module circuit for substation batteries, which can realize the safety, energy saving and environmental protection of the discharge process. The battery discharge process does not need to be separated from the busbar, and the DC power released by the battery is inverted into the same frequency and phase as the mains. The AC power is fed back to the power grid. When the battery discharges in case of abnormal conditions such as a power outage or a failure of the charging device, the discharge will be stopped immediately, and the power supply will be transferred to the bus.

In order to achieve the above purpose, the utility model is realized through the following technical solutions: an online discharge control module circuit for substation batteries, which is characterized in that it includes:

a first freewheeling diode;

A main circuit contactor and a charging contactor connected in parallel with the first freewheeling diode;

The anode of the first freewheeling diode is connected to the anode of the substation storage battery;

a first DC bus, connected to the negative pole of the battery in the substation;

A second DC bus, connected to the cathode of the first freewheeling diode.

The cathode of the first freewheeling diode is connected to the second DC bus through a first main circuit fuse.

The first DC bus and the second DC bus are connected to the AC bus through a charging module.

A second main circuit fuse is provided between the first DC bus and the negative pole of the substation battery.

Preferably, the online discharge control module circuit further includes a second freewheeling diode connected in parallel with the first freewheeling diode, the anode of the second freewheeling diode is connected to the anode of the first freewheeling diode, and its cathode is connected to the first freewheeling diode. Negative connection of a freewheeling diode.

Preferably, the circuit of the online discharge control module further includes an emergency switch, and the emergency switch is connected in parallel with the main circuit contactor.

Preferably, the on-line discharge control module circuit further includes a pair of parallel current-limiting charging resistors, which are connected in series with the charging contactor to the positive pole of the substation battery.

Compared with the prior art, an online discharge control module circuit for storage batteries in substations of the utility model has the following advantages: the discharge process of storage batteries in substations does not break away from the busbar, and safe discharge is realized; the access to the DC system is simple, and the working efficiency of nuclear capacity discharge tests is improved. ; No need to carry a heavy backup power supply, reducing labor intensity; online monitoring of "mains voltage", "bus voltage" and "inverter voltage", once an abnormality occurs, it will be transferred to the DC bus to supply power.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of an online discharge control module circuit for a substation storage battery according to the present invention.

Figure 2 is a diagram of an embodiment of the utility model.

Detailed ways

The utility model will be further elaborated below by describing a preferred specific embodiment in detail in conjunction with the accompanying drawings.

As shown in Figure 1, an on-line discharge control module circuit for substation batteries, including: a first freewheeling diode 1 (model: MURT20060, using heat sinks for heat dissipation, safety and insurance); connected in parallel with the first freewheeling diode 1 The main circuit contactor 2 (model: BCZ4-200-0111) and the charging contactor 3; the anode of the first freewheeling diode 1 is connected to the anode of the substation battery 4; a first DC bus 5 is connected to the The negative pole of the substation storage battery 4 ; a second DC bus 6 connected to the negative pole of the first freewheeling diode 1 . The cathode of the first freewheeling diode 1 is connected to the second DC bus 6 through a first main circuit fuse 7 .

The first DC bus 5 and the second DC bus 6 are connected to the AC bus through a charging module 8 .

A second main circuit fuse 9 is provided between the first DC bus 5 and the negative pole of the substation battery 4 .

Further, the online discharge control module circuit includes a second freewheeling diode 10 (model: MURT20060, adopting heat sink for heat dissipation, safety insurance) connected in parallel with the first freewheeling diode 1, and the anode of the second freewheeling diode 10 is connected to the first freewheeling diode 10. The positive pole of the freewheeling diode 1 is connected, and the negative pole thereof is connected with the negative pole of the first freewheeling diode 1 .

Further, the circuit of the online discharge control module includes an emergency switch 11 (model is GM5-63/2-C-63-08), and the emergency switch 11 is connected in parallel with the main circuit contactor 2 . The emergency switch 11 manually closes the positive circuit of the battery 4 of the substation to force charging and discharging to prevent the contacts of the main circuit contactor 2 from being in good contact; it is used in emergency and special circumstances and is usually disconnected.

Further, the online discharge control module circuit includes a pair of parallel current-limiting charging resistors 12 (using high-power resistors with a resistance value of 2R500W or 5R500W, the model is RXLG-500W-5RJ, using heat sinks to dissipate heat, which is safe), reducing the pressure difference when the pressure difference is large. The charging impact is connected to the positive pole of the substation storage battery 4 after being connected in series with the charging contactor 3 .

Specific application: As shown in Figure 2, the online discharge control module circuit is applied to the active inverter system of the substation storage battery. It can be converted into alternating current for actual load use, with high conversion efficiency, low calorific value, safe and reliable.

When discharging, since the voltage of the DC bus (the first DC bus 5 and the second DC bus 6 ) is higher than the voltage at the terminal 4 of the battery in the substation, the first freewheeling diode 1 and the second freewheeling diode 10 have reverse voltage. The first freewheeling diode 1 and the second freewheeling diode 10 are cut off, and the charging module 8 cannot charge the substation battery 4 at this time.

During the discharge process, if the mains power fails or the charging module 8 is completely turned off, the DC bus voltage drops. If the DC bus voltage is abnormal and the DC bus voltage is lower than the voltage at the terminal 4 of the substation battery, the first freewheeling diode 1 and the second freewheeling diode 1 The diode 10 is turned on, the substation storage battery 4 supplies power to the DC bus, and the power of the substation storage battery 4 is switched to be used by the load, so as to ensure uninterrupted power supply during load switching.

When the discharge starts, the main circuit contactor 2 of the normally closed contact is disconnected, and the substation storage battery 4 and the active inverter 13 form a discharge circuit.

After the discharge is terminated for a certain period of time (such as 10 minutes), the discharge circuit of the active inverter 13 is disconnected, the charging contactor 3 is closed, and the charging current of the charging module 8 charges the substation battery 4 through a pair of parallel current-limiting charging resistors 12 , avoid high current charging, and protect the substation battery 4.

After the discharge is terminated for a certain period of time (such as 10 minutes), the main circuit contactor 2 is closed, and the charging module 8 directly charges the substation battery 4 without a pair of parallel current-limiting charging resistors 12 .

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be recognized that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions of the present utility model will be obvious to those skilled in the art after reading the above content. Therefore, the protection scope of the present utility model should be defined by the appended claims.

Claims (7)

1. for an online control of discharge modular circuit for storage batteries of transformer substation, it is characterized in that, comprise:

One first fly-wheel diode (1);

The major loop contactor (2) in parallel with the first fly-wheel diode (1) and charging contactor (3);

The positive pole of described the first fly-wheel diode (1) is connected to the positive pole of storage batteries of transformer substation (4);

One first DC bus (5), connects the negative pole of described storage batteries of transformer substation (4);

One second DC bus (6), connects the negative pole of described the first fly-wheel diode (1).

2. online control of discharge modular circuit as claimed in claim 1, is characterized in that, the negative pole of described the first fly-wheel diode (1) is connected to the second DC bus (6) by one first major loop protective tube (7).

3. online control of discharge modular circuit as claimed in claim 1, is characterized in that, described the first DC bus (5) and the second DC bus (6) are connected to alternating current bus bar by a charging module (8).

4. online control of discharge modular circuit as claimed in claim 1, is characterized in that, between described the first DC bus (5) and the negative pole of described storage batteries of transformer substation (4), is provided with the second major loop protective tube (9).

5. online control of discharge modular circuit as claimed in claim 1, it is characterized in that, further comprise second fly-wheel diode (10) in parallel with the first fly-wheel diode (1), the positive pole of described the second fly-wheel diode (10) is connected with the positive pole of the first fly-wheel diode (1), and its negative pole is connected with the negative pole of described the first fly-wheel diode (1).

6. online control of discharge modular circuit as claimed in claim 1, is characterized in that, further comprises an emergency button (11), and described emergency button (11) is in parallel with described major loop contactor (2).

7. online control of discharge modular circuit as claimed in claim 1, is characterized in that, further comprises the current-limiting charge resistance (12) of a pair of parallel connection, with the positive pole that is connected storage batteries of transformer substation (4) after described charging contactor (3) series connection.