Parallel battery module and method

Abstract

The invention discloses a parallel battery module. The parallel battery module comprises a filtering circuit, a rectifying circuit, a PFC (Power Factor Correction) circuit, a first DC / DC converter, an energy storage element and a current limiting element which are sequentially connected, wherein an output end of the PFC circuit is connected with a storage battery through a second DC / DC converter, and charges the storage battery when an AC power supply is normal; the storage battery boosts and converts a DC power supply inputted by the storage battery into 110V or 220V DC voltage through a third DC / DC converter, the third DC / DC converter is connected with an output end of the first DC / DC converter in parallel, and the 110V or 220V DC voltage is outputted to a module output end through the energy storage element and the current limiting element. The parallel battery module acts as a hot backup of the first DC / DC converter in normal operation, can provide current output in overload, and drives a load together with the first DC / DC converter. The overload capacity of the parallel battery module is effectively improved.

Description

technical field [0001] The invention relates to a parallel battery module and a method. Background technique [0002] As the core part of the substation / power plant DC power system, the battery's reliability directly determines the reliability of the DC power system's power supply. The traditional DC power supply system is used by connecting multiple batteries in series to form a battery pack. [0003] The use of batteries in series has the following disadvantages: [0004] 1) The failure of a single battery affects the output of the whole group. It is difficult to precisely control the chemical reaction or ion migration inside the battery. The more the number of series connected batteries, the greater the probability of single failure. [0005] 2) The electrical parameters of the battery must be consistent. Batteries of different brands, different types, or even different batches of the same manufacturer cannot be mixed, and the utilization efficiency of the battery wil...

AI Technical Summary

Problems solved by technology

Batteries of different brands, different types, or even different batches of the same manufacturer cannot be mixed, and the utilization efficiency of the battery will be reduced

[0006] 3) It is difficult to expand the capacity of the battery pack, and it is generally necessary to replace the entire battery pack

[0007] 4) The battery pack can only be configured redundantly, and the cost of redundant configuration is high

[0008] 5) The battery pack cannot realize online full-capacity nuclear capacity, online maintenance and replacement

[0009] At present, parallel battery modules are usually used to solve the above problems, such as figure 2 As shown, however, when the AC input of the existing parallel battery modules loses power, the battery supplies power to the load through the two-stage DC conversion of the first DC conversion circuit and the second DC conversion circuit, and each DC conversion will lose part of the efficiency. The overall efficiency is low; the overload capacity is poor; when the load is short-circuited, the short-circuit current provided by the DC conversion circuit is small, and the circuit breaker of the fault circuit cannot be reliably disconnected, causing the fault range to expand

[0010] At the same time, the existing parallel battery modules are only for single-cell 12V lead-acid batteries, and the scope of application is narrow

Generally, there is no battery monitoring unit, and it is impossible to monitor parameters such as battery temperature, single-cell voltage, and single-cell internal resistance.

The protection, monitoring, and control functions of parallel battery modules are rarely mentioned, and the functions are not perfect and the efficiency of the DC conversion circuit is low

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