Power frequency rectification charging pile

Abstract

The utility model discloses a power frequency rectification charging pile, which comprises a power frequency rectification transformer, a filter circuit and a direct current voltage regulation module, the power frequency rectification transformer outputs 800V direct current electric energy with twelve pulse waves through two groups of three-phase full-bridge rectification circuits which are connected in series and staggered, and the power factor is improved to 0.98 after the direct current electric energy passes through the filter circuit. Equivalently, two three-phase full-bridge rectifier circuits and a filter circuit are used for replacing a PFC module of a traditional charging pile; in a high-power occasion, a large number of PFC modules of traditional charging piles are replaced, and the cost reduction effect is remarkable.

Description

Technical Field

[0001] The utility model belongs to the technical field of charging piles, and in particular relates to an industrial frequency rectification charging pile. Background Art

[0002] like Figure 1 As shown, the charging module in a traditional charging pile receives power from the high-voltage distribution network. The power is then routed through a 10kV high-voltage circuit breaker, transformer, and low-voltage distribution infrastructure to the charging pile, where it converts the low-voltage AC power into DC power for charging the electric vehicle battery. A traditional charging pile includes a PFC module and a DC voltage regulator module. The PFC module has two functions: 1. Rectification and boost: It converts 380V AC into 800V DC; 2. Power factor improvement: Through a control algorithm, the input current follows the input voltage with a near-zero phase difference, thereby achieving a power factor close to unity. The DC voltage regulator module receives the 800V DC power output from the PFC and converts it into the adjustable voltage and current required by the electric vehicle. Common power ratings for traditional charging pile modules range from 20kW, 30kW, and 40kW. Multiple modules are connected in parallel to achieve high charging power. Due to the relatively high cost of the PFC module, the cost of traditional charging pile modules is high, requiring further improvement. Utility Model Content

[0003] The utility model provides an industrial frequency rectification charging pile, which adopts an industrial frequency rectification transformer and a filter circuit to replace the PFC in the traditional charging module, greatly reducing the cost and having a higher cost performance than the traditional charging pile.

[0004] In order to solve the above problems, the technical solutions provided by the present invention are as follows:

[0005] The present invention provides an industrial frequency rectifier charging pile, comprising an industrial frequency rectifier transformer, a filter circuit, and a DC voltage regulation module. The industrial frequency rectifier transformer is composed of an ordinary transformer plus two sets of three-phase full-bridge rectifier circuits connected in series and staggered, and is used to receive 10kV AC power and output 800V, twelve-pulse DC power. The filter circuit is used to improve the waveform distortion and harmonics of the 800V DC voltage output by the industrial frequency rectifier transformer, improve the fundamental factor, thereby increasing the power factor to 0.98, reducing voltage ripple, and reducing the voltage transformation ratio of the subsequent DC voltage regulation module. The DC voltage regulation module is used to receive the 800V DC power filtered by the filter circuit and convert it into the voltage and current adjustable DC power required by the electric vehicle battery.

[0006] In an optional embodiment of the present invention, the power of the three-phase full-bridge rectifier circuit is a high power of 240 kW or above.

[0007] Compared with the prior art, the embodiments of the present invention provide an industrial frequency rectifier charging pile with the following beneficial effects: the industrial frequency rectifier transformer of the present invention outputs 800V, twelve-pulse DC power through two sets of three-phase full-bridge rectifier circuits interleaved in series, and then improves the power factor to 0.98 after passing through the filter circuit, which is equivalent to replacing the PFC module of a traditional charging pile with two three-phase full-bridge rectifier circuits plus a filter circuit; in high-power applications, it can replace a large number of PFC modules in traditional charging piles, significantly reducing costs. Taking a 720kW high-power conventional charging pile as an example, 36 20kW charging modules are required in parallel, including 36 20kW PFC modules; if the 36 20kW PFC modules are replaced by two high-power three-phase full-bridge rectifier circuits interleaved in series and a filter circuit of the present invention, the cost can be reduced by about 30%. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments or prior art, the following briefly introduces the drawings required for use in the embodiments or prior art descriptions. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0009] Figure 1 This is a structural diagram of the charging module of a traditional charging pile.

[0010] Figure 2 A schematic structural diagram of an industrial frequency rectification charging pile provided in an embodiment of the present application. DETAILED DESCRIPTION

[0011] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0012] like Figure 2As shown, an embodiment of the present invention provides an industrial frequency rectifier charging pile, including an industrial frequency rectifier transformer, a filter circuit and a DC voltage regulator module. The industrial frequency rectifier transformer is composed of an ordinary transformer plus two sets of three-phase full-bridge rectifier circuits connected in series and staggered, and is used to receive 10kV AC power and output 800V, twelve-pulse DC power. The filter circuit is used to improve the waveform distortion and harmonics of the 800V DC voltage output by the industrial frequency rectifier transformer, improve the fundamental factor, thereby increasing the power factor to 0.98, reducing the voltage ripple, and reducing the voltage transformation ratio of the subsequent DC voltage regulator module. The DC voltage regulator module is used to receive the 800V DC power filtered by the filter circuit and convert it into the voltage and current adjustable DC power required by the electric vehicle battery. The power of the three-phase full-bridge rectifier circuit is a high power of 240kW and above.

[0013] The industrial frequency rectifier transformer in this embodiment outputs 12-pulse DC power per cycle. Theoretically, the power factor can reach 0.9886. However, due to the leakage inductance of the transformer windings, the output voltage waveform undergoes some distortion during the commutation process, reducing the fundamental current content (i.e., the fundamental factor). This results in an actual power factor of approximately 0.95. Furthermore, the 12-pulse DC voltage ripple is relatively large. After filtering, the waveform distortion of the 800V DC voltage is significantly reduced, raising the power factor to 0.98.

[0014] The expected benefits and commercial value of the technical solution of this utility model after conversion are as follows: the industrial frequency rectifier transformer outputs 800V, twelve-pulse DC power through two sets of three-phase full-bridge rectifier circuits connected in series and interleaved. After passing through the filter circuit, the power factor is increased to 0.98, which is equivalent to replacing the PFC module with two three-phase full-bridge rectifier circuits plus a filter circuit. In low-power applications, the number of traditional PFC modules replaced is small, and the cost advantage is not obvious; in high-power applications, replacing a large number of PFC modules can significantly reduce costs. Taking a 720kW high-power conventional charging pile as an example, 36 20kW charging modules are required in parallel, including 36 20kW PFC modules. If the two high-power three-phase full-bridge rectifier circuits connected in series and interleaved plus a filter circuit of the utility model are used to replace the 36 20kW PFC modules, the cost can be reduced by about 30%.

[0015] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. A person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the claims.

Claims

1. A power frequency rectifier charging pile, characterized in that: The system comprises a power-frequency rectifier transformer, a filter circuit, and a DC voltage regulator module. The power-frequency rectifier transformer is composed of an ordinary transformer plus two sets of three-phase full-bridge rectifier circuits connected in series and interleaved. It is used to receive 10kV AC power and output 800V, twelve-pulse DC power. The filter circuit is used to improve the waveform distortion and harmonic characteristics of the 800V DC voltage output by the power-frequency rectifier transformer, thereby improving the fundamental factor, thereby increasing the power factor to 0.98, reducing voltage ripple, and reducing the voltage transformation ratio of the subsequent DC voltage regulator module. The DC voltage regulator module is used to receive the 800V DC power filtered by the filter circuit and convert it into the voltage and current adjustable DC power required by the electric vehicle battery.

2. The power frequency rectification charging pile according to claim 1, characterized in that: The power of the three-phase full-bridge rectifier circuit is a high power of 240kW or above.

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