Special voltage sag compensation device for super-capacitor type frequency converter

Abstract

The utility model relates to the field of power electronic technology and electric energy quality management, in particular to a voltage sag compensation device special for a super capacitor type frequency converter, which comprises a back-up power supply module and a power supply management module. According to the utility model, through integration of the backup power supply module and the power supply management module, real-time monitoring and rapid response to the voltage of the power grid are realized. When voltage sag occurs, the device can be quickly started, the power management module controls the backup power supply module to provide electric energy for the direct current side of the frequency converter, voltage stability is ensured, shutdown of the frequency converter due to power shortage is avoided, and normal operation of a sensitive load is protected. The device is easy and convenient to install, compared with a traditional parallel compensation device, the electric energy loss in the floating charge state is reduced, the compensation time can be customized according to actual requirements, and the overall efficiency and reliability of the system are improved.

Description

Technical Field

[0001] The utility model relates to the fields of power electronics technology and power quality management, and specifically, to a special voltage sag compensation device for a supercapacitor type frequency converter. Background Art

[0002] In modern power systems, stable and reliable power supply is the foundation to ensure the orderly progress of industrial production, commercial operation, and even daily life. However, the power grid often faces the challenge of voltage sag during operation, which is caused by various factors, including but not limited to transmission line faults, starting operations of large-scale electrical equipment, etc. Although the voltage sag is short, its impact is profound. It can cause the frequency converter that relies on stable voltage operation to stop working due to momentary power shortage, and then affect sensitive loads that rely on the speed control of the frequency converter, such as precision manufacturing equipment, medical instruments, etc. Such shutdowns not only interrupt the production process and increase economic losses, but also can trigger a chain reaction in severe cases, leading to power outages in local areas of the power grid and even causing major electrical safety accidents.

[0003] In view of the universality and potential hazards of the voltage sag phenomenon, the prior art has proposed a solution, that is, a voltage sag compensation device is installed in parallel on the DC side of the frequency converter. This device is designed compactly, with a small volume, and its shape is close to a computer chassis, which is convenient for installation and occupies little space, and is very suitable for implementation in various environments. The core component is a supercapacitor module, which is an efficient energy storage unit that can quickly release electrical energy at the moment when the grid voltage suddenly drops, fill the voltage gap, help the frequency converter survive the sag period, and ensure its continuous operation. In order to enhance the interactivity and monitorability of the system, a communication module is also integrated, which can transmit the voltage and current information of the supercapacitor to the monitoring center in real time, facilitating the operation and maintenance personnel to master the operating status of the equipment and make timely responses.

[0004] Although the prior art has alleviated the problems caused by voltage sag to a certain extent, the power consumption in its continuous floating charge state has become a drawback that cannot be ignored. This means that the device continuously consumes electrical energy even in non-emergency situations, increasing the operating cost of the system and reducing the overall energy efficiency. Therefore, seeking an innovative solution that can effectively cope with voltage sag and reduce energy losses during normal times has become an urgent need in the current power technology field. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a special voltage sag compensation device for a supercapacitor type frequency converter to solve the problem of continuous power consumption of the voltage sag compensation device in the floating charge state proposed in the above background art.

[0006] To achieve the above object, the present utility model provides a voltage sag compensation device for a supercapacitor type frequency converter, which includes a backup power supply module and a power management module. The power management module includes a voltage detection unit, a power management controller, and a voltage conversion unit. The backup power supply module is connected to the power management controller and the voltage conversion unit;

[0007] The voltage sag compensation device is connected in parallel to the DC side of the frequency converter;

[0008] Wherein a rectification unit is provided in the frequency converter, and the rectification unit is used to convert an AC circuit into a DC circuit;

[0009] The power management controller is connected to the DC circuit and can charge the backup power supply module;

[0010] The power management controller is connected to the voltage detection unit. The voltage detection unit is used to detect the DC side voltage in real time. When the voltage is abnormal, the backup power supply module releases electrical energy to supply power to the frequency converter to compensate to the specified voltage.

[0011] As a further improvement of this technical solution, the voltage conversion unit includes a transformer T2, a triode VT1, a diode D1, and a capacitor C1. The positive pole of the main winding of the transformer T2 is connected to the positive pole of the backup power supply module. The negative pole of the main winding of the transformer T2 is connected to the collector of the triode VT1. The emitter of the triode VT1 is connected to the negative pole of the backup power supply module. The base of the triode VT1 is connected to the power management controller. The positive pole of the secondary winding of the transformer T2 is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive pole of the capacitor C1 and the positive pole of the DC side of the frequency converter. The negative pole of the secondary winding of the transformer T2 is connected to the negative pole of the capacitor C1 and the negative pole of the DC side of the frequency converter.

[0012] As a further improvement of this technical solution, the voltage detection unit is provided with a transformer T1. The positive pole of the main winding of the transformer T1 is connected to a fuse FU1. The other end of the fuse FU1 is connected to the positive pole of the DC side of the frequency converter. The negative pole of the main winding of the transformer T1 is connected to a fuse FU2. The other end of the fuse FU2 is connected to the negative pole of the DC side of the frequency converter. The positive pole of the secondary winding of the transformer T1 is connected to a fuse FU3. The negative pole of the secondary winding of the transformer T1 is grounded. The secondary winding of the transformer T1 is connected in parallel with a voltage detector V and a voltage drop U<, and the secondary winding of the transformer T1 is connected to the power management controller.

[0013] As a further improvement of this technical solution, the power management controller is connected to the backup power supply module, the base of the triode VT1, the voltage detection unit, and the DC side of the frequency converter.

[0014] As a further improvement of this technical solution, the backup power supply module integrates a supercapacitor module, a capacitor management unit, and a communication module.

[0015] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0016] 1. In the supercapacitor type voltage sag compensation device for a frequency converter, the capacitor management unit integrated in the backup power supply module monitors the capacitor state in real time, and the communication module transmits the capacitor data in real time. Then, through the charge and discharge strategy optimized by the power management controller, the energy waste in daily operation is greatly reduced, thereby significantly improving the overall energy efficiency without affecting the emergency response ability.

[0017] 2. In the supercapacitor type voltage sag compensation device for a frequency converter, through the backup power supply module and the power management module, the protection mechanism is not only limited to voltage sags, but also covers extreme situations such as voltage interruptions, and the compensation time can be customized according to the on-site situation, providing comprehensive power protection for the frequency converter and subsequent loads, and enhancing the stability and reliability of the entire power system.

[0018] 3. In the supercapacitor type voltage sag compensation device for a frequency converter, this device is directly installed on the DC side of the frequency converter, with a simple structure. A modular box design can be adopted, making the size compact, the installation process simple and fast, the layout flexible, and having low requirements for the installation space, which helps to reduce the installation cost and time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the overall structure of the present utility model;

[0020] Figure 2 is a circuit diagram of the voltage sag compensation device for the frequency converter of the present utility model.

[0021] The meanings of each label in the figure are as follows:

[0022] 100, frequency converter; 110, rectification unit; 120, inversion unit; 210, power management module; 211, power management controller; 212, voltage conversion unit; 213, voltage detection unit; 220, backup power supply module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0024] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0025] Please refer to Figure 1 - Figure 2 As shown, this embodiment provides a dedicated voltage sag compensation device for a supercapacitor type frequency converter, which includes a backup power supply module 220 and a power management module 210. The power management module 210 includes a voltage detection unit 213, a power management controller 211, and a voltage conversion unit 212. The backup power supply module 220 is connected to the power management controller 211 and the voltage conversion unit 212;

[0026] The voltage sag compensation device is connected in parallel to the DC side of the frequency converter 100;

[0027] Among them, a rectification unit 110 is provided in the frequency converter 100, and the rectification unit 110 is used to convert an AC circuit into a DC circuit;

[0028] The power management controller 211 is connected to the DC circuit and can charge the backup power supply module 220;

[0029] The power management controller 211 is connected to the voltage detection unit 213. The voltage detection unit 213 is used to detect the voltage condition of the DC side in real time. When the voltage is abnormal, the backup power supply module 220 releases electrical energy to supply power to the frequency converter 100 to compensate to the specified voltage.

[0030] The voltage conversion unit 212 includes a transformer T2, a triode VT1, a diode D1, and a capacitor C1. The positive pole of the main winding of the transformer T2 is connected to the positive pole of the backup power supply module 220, the negative pole of the main winding of the transformer T2 is connected to the collector of the triode VT1, the emitter of the triode VT1 is connected to the negative pole of the backup power supply module 220, the base of the triode VT1 is connected to the power management controller 211, the positive pole of the secondary winding of the transformer T2 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the positive pole of the capacitor C1 and the positive pole of the DC side of the frequency converter 100, and the negative pole of the secondary winding of the transformer T2 is connected to the negative pole of the capacitor C1 and the negative pole of the DC side of the frequency converter 100. When the voltage is abnormal, the power management controller 211 receives the abnormal voltage condition detected by the voltage detection unit 213 and calculates the required voltage difference for compensation, controls the discharge of the backup power supply module 220, and then controls the switch of the triode VT1, adjusts the output of the required compensation voltage through the transformer, and outputs it to the frequency converter 100 to ensure the stable power supply of the frequency converter 100.

[0031] The voltage detection unit 213 is provided with a transformer T1. The positive pole of the main winding of the transformer T1 is connected to the fuse FU1, and the other end of the fuse FU1 is connected to the positive pole of the DC side of the frequency converter 100. The negative pole of the main winding of the transformer T1 is connected to the fuse FU2, and the other end of the fuse FU2 is connected to the negative pole of the DC side of the frequency converter 100. The positive pole of the secondary winding of the transformer T1 is connected to the fuse FU3, the negative pole of the secondary winding of the transformer T1 is grounded, the voltage detector V and the voltage drop U< are connected in parallel to the secondary winding of the transformer T1, and the secondary winding of the transformer T1 is connected to the power management controller 211. The transformer T1 is connected with fuses and grounded to protect the circuit from harm when the voltage is abnormal. The voltage detector V and the voltage drop detector U< are connected in parallel to the secondary winding of the transformer T1 to achieve accurate voltage monitoring, and finally connected to the power management controller 211 to transmit voltage data to the power management controller 211 in real time.

[0032] The power management controller 211 is connected to the backup power supply module 220, the base of the triode VT1, the voltage detection unit 213 and the DC side of the frequency converter 100.

[0033] The backup power supply module 220 integrates a supercapacitor module, a capacitor management unit and a communication module. Cooperating with the power management controller 211 to optimize the charging and discharging strategy of the supercapacitor module, the supercapacitor is charged only when necessary, greatly reducing the power loss in the daily floating charge state, improving the overall energy efficiency, and the compensation time can also be customized according to the on-site situation, enhancing the power protection of the frequency converter 100 and subsequent loads.

[0034] Working principle:

[0035] The rectification unit 110 provided in the frequency converter 100 converts the input alternating current into direct current. The parallel intermediate capacitor smoothes the voltage fluctuation, filters the high-frequency noise and ripple generated by the rectifier. After the direct current flows to the inversion unit 120, it is converted into alternating current and supplied to the load to maintain the normal use of the frequency converter 100. The voltage sag compensation device is connected in parallel to the DC side of the frequency converter 100. The current flows directly to the backup power supply module 220 through the power management controller 211 to charge it. At the same time, the parallel voltage detection unit 213 monitors the voltage of the DC side of the frequency converter 100 in real time. When the power supply voltage is normal, while the rectification unit 110 in the frequency converter 100 establishes a DC system for the frequency converter 100, it directly charges the backup power supply module 220 through the power management controller 211, and detects the voltage situation in real time through the voltage detection unit 213. When the voltage is abnormal, the power management controller 211 controls the backup power supply module 220 to release electrical energy and adjusts the voltage to supply power to the frequency converter 100 through the voltage conversion unit 212. When the power supply voltage is restored, the frequency converter 100 resumes power supply from the power supply. At the same time, the rectification unit 110 of the frequency converter 100 continues to charge the backup power supply module 220. When the electrical energy is full, the power supply to the backup power supply module 220 is cut off through the power management controller 211.

[0036] The above has shown and described the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only preferred examples of the present utility model and are not used to limit the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and all these changes and improvements fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. A voltage sag compensation device dedicated to a supercapacitor type frequency converter, characterized in that: It includes a backup power supply module (220) and a power management module (210). The power management module (210) includes a voltage detection unit (213), a power management controller (211), and a voltage conversion unit (212). The backup power supply module (220) is connected to the power management controller (211) and the voltage conversion unit (212). The voltage sag compensation device is connected in parallel to the DC side of the frequency converter (100). Among them, a rectification unit (110) is provided in the frequency converter (100), and the rectification unit (110) is used to convert an AC circuit into a DC circuit. The power management controller (211) is connected to the voltage conversion unit (212) and can charge the backup power supply module (220). The power management controller (211) is connected to the voltage detection unit (213). The voltage detection unit (213) is used to detect the DC side voltage in real time. When the voltage is abnormal, the backup power supply module (220) releases electrical energy to supply power to the frequency converter (100) to compensate to the specified voltage.

2. A voltage sag compensation device for a supercapacitor type frequency converter according to claim 1, characterized in that: The voltage conversion unit (212) includes a transformer T2, a triode VT1, a diode D1, and a capacitor C1. The positive pole of the main winding of the transformer T2 is connected to the positive pole of the backup power supply module (220). The negative pole of the main winding of the transformer T2 is connected to the collector of the triode VT1. The emitter of the triode VT1 is connected to the negative pole of the backup power supply module (220). The base of the triode VT1 is connected to the power management controller (211). The positive pole of the secondary winding of the transformer T2 is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the positive pole of the capacitor C1 and the positive pole of the DC side of the frequency converter (100). The negative pole of the secondary winding of the transformer T2 is connected to the negative pole of the capacitor C1 and the negative pole of the DC side of the frequency converter (100).

3. The voltage sag compensation device for a supercapacitor type frequency converter according to claim 1, characterized in that: The voltage detection unit (213) is provided with a transformer T1. The positive pole of the main winding of the transformer T1 is connected to a fuse FU1. The other end of the fuse FU1 is connected to the positive pole of the DC side of the frequency converter (100). The negative pole of the main winding of the transformer T1 is connected to a fuse FU2. The other end of the fuse FU2 is connected to the negative pole of the DC side of the frequency converter (100). The positive pole of the secondary winding of the transformer T1 is connected to a fuse FU3. The negative pole of the secondary winding of the transformer T1 is grounded. The secondary winding of the transformer T1 is connected in parallel with a voltage detector V and a voltage drop U<, and the secondary winding of the transformer T1 is connected to the power management controller (211).

4. The voltage sag compensation device for a supercapacitor type frequency converter according to claim 3, characterized in that: The power management controller (211) is connected to the backup power supply module (220), the base of the triode VT1, the voltage detection unit (213), and the DC side of the frequency converter (100).

5. A voltage sag compensation device for a supercapacitor type frequency converter according to claim 1, characterized in that: The backup power supply module (220) integrates a supercapacitor module, a capacitor management unit, and a communication module.

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