Smart energy box-type transformer substation

Abstract

The invention provides a smart energy box-type substation. The smart energy box-type substation comprises a phase-shifting transformer; one end of the alternating current contactor is connected with the secondary side of the phase-shifting transformer; a rectifier module; the voltage regulation circuit is arranged between the direct current output end of the rectification module and a load, and the voltage regulation circuit comprises a resistor and a direct current contactor which are connected in series; and the central processing unit is used for acquiring a voltage value input to the load and controlling the direct current contactor and the alternating current contact according to a set voltage upper limit value, a set voltage lower limit value and the corrected voltage value so as to adjust the voltage value input to the load. By controlling whether the voltage regulating circuit is connected or not, the voltage value input to the load can be quickly adjusted in advance, the phenomenon that the whole machine is shut down or the load cannot be started in time due to power grid voltage fluctuation, direct current side capacitor charging and discharging and the like is prevented, the benefit of the smart energy box transformer substation is improved, and the whole device is simple in element, durable, economical and convenient to use. A control logic program is easy to compile and high in response speed.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment, and particularly to an intelligent energy box transformer. Background Art

[0002] An intelligent energy box transformer is a highly integrated device in the power system. It integrates a high-voltage unit, a transformer unit, and a low-voltage unit, and not only has the basic functions of receiving and distributing electric energy, but also realizes the control, protection, and precise monitoring of the circuit.

[0003] Due to grid fluctuations and the charging and discharging of the DC-side capacitor, the output voltage of the intelligent energy box transformer may fluctuate. Once it reaches the set upper or lower limit of the output voltage, it may cause the intelligent energy box transformer to directly shut down, or the load cannot be started in time.

[0004] In related technologies, although there is a solution to increase the voltage withstand module to improve the voltage withstand value of the whole machine and increase the shutdown upper limit of the whole machine, this method will cause the volume of the whole device to become larger and the energy consumption of internal components to become larger. In addition, the electronic circuit design of the voltage withstand module generally uses IGBT (Insulate-Gate Bipolar Transistor) or silicon carbide, and it is necessary to use PWM (Pulse Width Modulation) to adjust the angle of IGBT or silicon carbide. This will not only increase the number of peripheral discrete components, aggravate the EMC (Electromagnetic Compatibility) anti-interference, increase the workload of single-chip microcomputer program writing, but also cause problems such as high professional requirements, high price, and high maintenance cost, resulting in inconvenient operation and maintenance and low yield. Summary of the Invention

[0005] To solve the above technical problems, the object of the present invention is to provide an intelligent energy box transformer.

[0006] The technical solution adopted by the present invention is as follows:

[0007] An embodiment of the first aspect of the present invention provides a smart energy box transformer, comprising: a phase-shifting transformer, the primary side of the phase-shifting transformer is connected to alternating current; an AC contactor, one end of the AC contactor is connected to the secondary side of the phase-shifting transformer; a rectification module, the AC input end of the rectification module is connected to the other end of the AC contactor; a voltage regulation circuit, the voltage regulation circuit is arranged between the DC output end of the rectification module and the load, and the voltage regulation circuit includes: a resistor and a DC contactor connected in series; a central processing unit, the central processing unit is used to obtain the voltage value Ucharge input to the load, and according to the set voltage upper limit value Umax, the set voltage lower limit value Umin and the corrected voltage value ΔU, control the DC contactor and the AC contactor to adjust the voltage value Ucharge input to the load, where Umax > Umin > ΔU.

[0008] The smart energy box transformer proposed above in the present invention may further have the following additional technical features:

[0009] According to an embodiment of the present invention, the central processing unit is specifically used for: obtaining a corrected voltage upper limit value according to (Umax - ΔU1), obtaining a corrected voltage lower limit value according to (Umin + ΔU2), ΔU1 is the first voltage correction value, and ΔU2 is the second voltage correction value; if there is (Umax - ΔU1) ≤ Ucharge < Umax, then drive the DC relay to close to reduce the voltage value Ucharge input to the load to the standard voltage value, where Umin < standard voltage value < Umax; if there is Umin ≤ Ucharge < (Umin + ΔU2), then drive the DC relay to open to increase the voltage value Ucharge input to the load to the standard voltage value.

[0010] According to an embodiment of the present invention, the central processing unit is further used for: if there is Ucharge ≤ Umin or Ucharge ≥ Umax, then control the AC contactor to open to control the smart energy box transformer to shut down.

[0011] According to an embodiment of the present invention, the central processing unit is further used for: obtaining the current value I input to the load, if there is I ≥ Imax, where Imax is the set current threshold, then control the AC contactor to open to control the smart energy box transformer to shut down.

[0012] According to an embodiment of the present invention, the central processing unit is further used for: obtaining the temperature value T of the secondary side winding of the phase-shifting transformer, if there is T ≥ Tmax, where Tmax is the set temperature threshold, then control the AC contactor to open to control the smart energy box transformer to shut down.

[0013] According to an embodiment of the present invention, the above-mentioned intelligent energy box transformer further includes: a capacitor, and the capacitor is connected in parallel with the DC output terminal of the rectification module.

[0014] According to an embodiment of the present invention, the load is a rectifier cabinet of a charging pile.

[0015] Advantages of the present invention:

[0016] The present invention can, when the voltage value input to the load is close to the set threshold, control whether the voltage regulation circuit is connected, so as to quickly adjust in advance the voltage value input to the load, making the voltage value input to the load always within the threshold range, preventing the phenomenon that the intelligent energy box transformer directly shuts down or the load cannot be started in time due to reasons such as power grid voltage fluctuations and DC side capacitor charging and discharging, improving the efficiency of the intelligent energy box transformer, and the entire control logic program is easy to write and has a fast response speed. The entire device does not need to additionally adopt a voltage withstand module, and the components are simple, durable, economical, and have strong EMC anti-interference.

[0017] The present invention also real-time tracks the current and temperature of the intelligent energy box transformer, and if either of them exceeds the corresponding threshold, it controls the shutdown protection of the whole machine to avoid losses caused by overcurrent and overheating. Description of the Drawings

[0018] Figure 1 is the electrical topology diagram of the intelligent energy box transformer according to an embodiment of the present invention;

[0019] Figure 2 is the working flow chart of the central processing unit according to an embodiment of the present invention. Detailed Embodiments

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Figure 1 is the electrical topology diagram of the intelligent energy box transformer according to an embodiment of the present invention, as Figure 1 shown, the intelligent energy box transformer includes: a phase-shifting transformer T, an AC contactor KM, a rectification module D, a voltage regulation circuit, and a central processing unit.

[0022] Among them, the primary side of the phase-shifting transformer T is connected to the alternating current (UA, UB, and UC); one end of the AC contactor KM is connected to the secondary side of the phase-shifting transformer T; the AC input end of the rectification module D is connected to the other end of the AC contactor KM; the voltage regulation circuit is arranged between the DC output end of the rectification module D and the load, and the voltage regulation circuit includes: a resistor R and a DC contactor KMz connected in series; the central processor is used to obtain the voltage value Ucharge input to the load, and according to the set voltage upper limit value Umax, the set voltage lower limit value Umin, and the correction voltage value ΔU, control the DC contactor KMz and the AC contact KM to adjust the voltage value Ucharge input to the load, where Umax > Umin > ΔU.

[0023] Specifically, the alternating currents UA, UB, and UC are 10 kV AC voltages on the grid side, the phase-shifting transformer T can be a 12-phase 24-pulse phase-shifting transformer, QF is an AC circuit breaker, the rectification module D can be a 12-phase 24-pulse full-bridge rectification module, and the central processor can be a PLC (Programmable Logic Controller). The central processor controls the DC contactor KMz and the AC contact in real time according to the voltage value Ucharge input to the load detected by the voltage hall TV, the set voltage upper limit value Umax, the set voltage lower limit value Umin, and the correction voltage value ΔU to adjust the voltage value Ucharge input to the load. The grid fluctuation and the charge and discharge of the DC side capacitor are a gradually changing process. When Ucharge is about to reach the set voltage upper limit value Umax or the set voltage lower limit value Umin, the DC contactor KMz is controlled to control whether the resistor R is connected to the circuit, so as to adjust the voltage value Ucharge input to the load, complete the correction of Ucharge, and make the voltage value input to the load be corrected within the threshold range in time, preventing the phenomenon that the intelligent energy box transformer directly shuts down or the load cannot be started in time due to reasons such as grid voltage fluctuation and charge and discharge of the DC side capacitor, improving the efficiency of the intelligent energy box transformer, and the entire control logic program is easy to write and has a fast response speed. The entire device does not need to adopt a voltage withstand module additionally, and the components are simple, durable, economical, and have strong EMC anti-interference.

[0024] In the embodiment of the present invention, for the set voltage upper limit value Umax, the set voltage lower limit value Umin, and the correction voltage value ΔU, the user can set them on the HMI (Human Machine Interface) according to actual needs, and can set parameters at any time locally and remotely through the mobile phone cloud to ensure the safe operation of the system. For example, the voltage upper limit value Umax can be 860 V, the voltage lower limit value Umin can be 630 V, and the correction voltage value ΔU can be 10 V - 20 V.

[0025] The resistor R can be a wire-wound resistor.

[0026] In an embodiment of the present invention, as Figure 1 shown, the above-mentioned intelligent energy box transformer further includes: a capacitor C, and the capacitor C is connected in parallel with the DC output terminal of the rectification module D. The setting of the capacitor C can improve the power quality.

[0027] The following describes how the central processing unit controls the voltage regulation circuit in combination with specific embodiments.

[0028] According to an embodiment of the present invention, the central processing unit is specifically configured to: obtain a corrected voltage upper limit value according to (Umax - ΔU1), obtain a corrected voltage lower limit value according to (Umin + ΔU2), where ΔU1 is a first voltage correction value and ΔU2 is a second voltage correction value (S1); if there is (Umax - ΔU1) ≤ Ucharge < Umax, drive the DC relay to close, so that the voltage value Ucharge input to the load is reduced to the standard voltage value, where Umin < standard voltage value < Umax (S2); if there is Umin ≤ Ucharge < (Umin + ΔU2), drive the DC relay to open, so that the voltage value Ucharge input to the load is increased to the standard voltage value (S3); if there is Ucharge ≤ Umin, or Ucharge ≥ Umax, control the AC contactor to open to control the shutdown of the intelligent energy box transformer (S4).

[0029] Specifically, (Umax - ΔU1) is used as the corrected voltage upper limit value, and (Umin + ΔU2) is used as the corrected voltage lower limit value; ΔU1 and ΔU2 can be set according to actual conditions, and ΔU1 and ΔU2 can be the same or different. For example, 10V, 20V, etc., and the standard voltage value can be 720V, and the resistance value of R is set according to actual conditions. If 850V ≤ Ucharge < 860V, the central processing unit issues an instruction to the hardware port to drive the DC contactor KMz to close. At this time, Ucharge will quickly reduce the voltage to 720Vdc due to the input of the resistor R to complete the high-voltage value step-down; if 630V ≤ Ucharge < 640V, the central processing unit issues an instruction to the hardware port to drive the DC contactor KMz to open and close, and Ucharge will quickly rise to about 720Vdc because there is no resistor R input. Thus, the adjustment is carried out cyclically to achieve the purpose of adjusting the voltage segment. If there is Ucharge ≤ 630, or Ucharge ≥ 860, it means that the output voltage reaches the upper limit or the lower limit. To ensure the safety of the circuit, the central processing unit also controls the AC contactor KM to directly open to control the shutdown protection of the intelligent energy box transformer.

[0030] In an embodiment of the present invention, the central processing unit can also be used to: obtain the current value I input to the load. If there is I≥Imax, where Imax is a set current threshold, then control the AC contactor to disconnect to control the intelligent energy box transformer to shut down.

[0031] Specifically, as Figure 1 shown, the central processing unit can obtain the current value I input to the load through the current Hall TA. If I≥Imax, it indicates that the intelligent energy box transformer is overcurrent. The central processing unit controls the AC contactor KM to directly disconnect to control the intelligent energy box transformer to shut down and sends an alarm message in time to prevent the expansion of the backend fault point and cause losses, and also prevent overcapacity.

[0032] In an embodiment of the present invention, the central processing unit can also be used to: obtain the temperature value T of the secondary winding of the phase-shifting transformer. If there is T≥Tmax, where Tmax is a set temperature threshold, then control the AC contactor to disconnect to control the intelligent energy box transformer to shut down.

[0033] Specifically, the highest temperature value of the diode modules in phases A, B, and C of the secondary winding of the phase-shifting transformer can be obtained as the temperature value T. Once T≥Tmax, it indicates that there is a risk of overheating. The central processing unit controls the AC contactor KM to directly disconnect to control the intelligent energy box transformer to shut down and sends an alarm message in time. Since the temperature difference in each region is different, Tmax can be continuously adjusted through on-site local temperature measurement operation to optimize the valve to achieve lean adjustment.

[0034] In an embodiment of the present invention, the load can be a charging pile rectifier cabinet.

[0035] In summary, according to the intelligent energy box transformer of the embodiments of the present invention, when the voltage value input to the load is close to the set threshold, by controlling whether the voltage regulating circuit is connected, the voltage value input to the load can be quickly adjusted in advance, so that the voltage value input to the load is always within the threshold range, preventing the phenomenon that the intelligent energy box transformer directly shuts down or the load cannot be started in time due to reasons such as power grid voltage fluctuations and DC side capacitor charging and discharging, improving the efficiency of the intelligent energy box transformer. Moreover, the entire control logic program is easy to write and has a fast response speed. The entire device does not need to additionally adopt a voltage withstand module, and the components are simple, durable, economical, and have strong EMC anti-interference. It also real-time tracks the current and temperature of the intelligent energy box transformer. If either of them exceeds the corresponding threshold, it controls the whole machine to shut down for protection to avoid losses caused by overcurrent and overheating.

[0036] In the description of the present invention, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Any process or method description represented in a flowchart or otherwise described herein can be understood to represent a module, segment, or portion of code including one or more executable instructions for implementing a customized logical function or process, and the scope of the preferred embodiments of the present invention includes additional implementations, where the functions can be executed in a substantially simultaneous manner or in an order opposite to that shown or discussed, according to the functions involved, which should be understood by those skilled in the technical field to which the embodiments of the present invention pertain.

[0037] The logic and / or steps represented in a flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing a logical function, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch and execute instructions from the instruction execution system, apparatus, or device), or in connection with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection portion having one or more wirings (electronic device), a portable computer diskette (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, followed by editing, interpretation, or other appropriate processing as necessary, and then stored in a computer memory.

[0038] Those of ordinary skill in the art of this technology can understand that all or part of the steps carried by the methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. When the program is executed, it includes one or a combination of the steps of the method embodiments.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A smart energy box transformer, characterized in that: include: A phase-shifting transformer, wherein the primary side of the phase-shifting transformer is connected to the alternating current; An AC contactor, one end of which is connected to the secondary side of the phase-shifting transformer; A rectifier module, wherein an AC input end of the rectifier module is connected to the other end of the AC contactor; A voltage regulating circuit, which is arranged between the DC output terminal of the rectifier module and the load, and comprises: a resistor and a DC contactor connected in series; The central processing unit is used to obtain the voltage value Ucharge input to the load, and control the DC contactor and the AC contact according to the set voltage upper limit value Umax, the set voltage lower limit value Umin and the correction voltage value ΔU to adjust the voltage value Ucharge input to the load, wherein Umax>Umin>ΔU.

2. The smart energy box transformer according to claim 1 is characterized in that: The central processing unit is specifically used for: The corrected voltage upper limit is obtained according to (Umax-ΔU1), and the corrected voltage lower limit is obtained according to (Umin+ΔU2), ΔU1 is the first voltage correction value, and ΔU2 is the second voltage correction value; If (Umax-ΔU1)≤Ucharge<Umax exists, the DC relay is driven to close, so that the voltage value Ucharge input to the load is reduced to the standard voltage value, Umin<standard voltage value<Umax; If Umin≤Ucharge<(Umin+ΔU2), the DC relay is driven to be disconnected, so that the voltage value Ucharge input to the load is increased to the standard voltage value.

3. The smart energy box transformer according to claim 2 is characterized in that: The central processing unit is also used for: If Ucharge≤Umin, or Ucharge≥Umax exists, the AC contactor is controlled to be disconnected to control the smart energy box to shut down.

4. The smart energy box transformer according to claim 1 is characterized in that: The central processing unit is also used for: The current value I input to the load is obtained. If I≥Imax exists, and Imax is the set current threshold, the AC contactor is controlled to be disconnected to control the smart energy box to shut down.

5. The smart energy box transformer according to claim 1 is characterized in that: The central processing unit is also used for: The temperature value T of the secondary winding of the phase-shifting transformer is obtained. If T≥Tmax exists, Tmax is a set temperature threshold, the AC contactor is controlled to be disconnected to control the smart energy box transformer to shut down.

6. The smart energy box transformer according to claim 1 is characterized in that: Also includes: A capacitor is connected in parallel with a DC output terminal of the rectifier module.

7. The smart energy box transformer according to claim 1 is characterized in that: The resistor is a wire-wound resistor.

8. The smart energy box transformer according to claim 1 is characterized in that: The load is a charging pile rectifier cabinet.

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