[0032] The invention provides a hybrid uninterruptible power supply system, which makes full use of the advantages of static UPS and rotating UPS, provides timely and reliable uninterrupted power supply for downstream load equipment, and ensures the safe operation of downstream load equipment.
[0033] In order to make full use of the advantages of the static UPS and the rotating UPS, the present invention combines the static UPS and the rotating UPS to form a hybrid UPS. It has the advantages of static and rotating UPS at the same time, such as small output impedance, small output power distortion, high reliability, strong transient overload capability and fast dynamic frequency response. There are three common types of hybrid UPS, one is offline hybrid UPS, which is composed of offline UPS and rotary UPS, the other is online interactive hybrid UPS, which is composed of online interactive UPS and rotary UPS, and the third is On-line hybrid UPS is composed of on-line UPS and rotary UPS. The advantages and disadvantages of each structure are related to the characteristics of its components.
[0034] In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.
[0035] See image 3 , This figure is a structural diagram of a hybrid uninterruptible power supply system according to an embodiment of the present invention.
[0036] The hybrid uninterruptible power supply system according to the embodiment of the present invention includes: a Fast Utility Disconnect (FUD), a generator, a diesel engine, a motor/generator device, a bidirectional converter, and a battery.
[0037] The generator is connected to the quick power cut-off device.
[0038] The diesel engine is connected to the generator through a clutch.
[0039] The battery is connected to the bidirectional converter, and the bidirectional converter is connected to the motor/generator device;
[0040] The generator is coaxial with the motor/generator device.
[0041] The fast power cut-off device is connected in series with the input power supply and the downstream load equipment ( image 3 Not shown in). When the input power fails or the power is interrupted, the path between the input power and the downstream load equipment is quickly disconnected. When the input power source is normal, the input power source charges the battery through the generator, the motor/generator device, and the bidirectional converter. When the input power fails, the battery is discharged, and energy is provided to the downstream load device through the bidirectional converter, the motor/generator device and the generator. While the battery is discharged to provide energy to the downstream load equipment, the diesel engine completes the starting process. After the diesel engine starts normally, the battery stops supplying power, and the diesel engine drives the generator to provide power to the downstream equipment.
[0042] The electric/generator device works in the generator state when charging the battery; the electric/generator device works in the motor state when driving the diesel engine and generator.
[0043] The input power source may specifically be a power source provided by the medium-voltage power grid after passing through a power station transformer.
[0044] The voltage of the medium-voltage power grid is transformed by the medium-voltage power station transformer and used as the input power source. The input power source is connected to the fast power cut-off device FUD to supply power to the downstream medium-voltage input power distribution unit and other equipment when the grid voltage is normal.
[0045] The fast power cut-off device FUD quickly disconnects the path between the input power and the downstream load equipment when the input power fails or the power is interrupted, so as to avoid threats to the downstream load equipment. When the input power is normal, the input voltage charges the battery through the generator and the coaxial motor/generator and the two-way converter; when the input power fails, the battery discharges and goes backwards through the two-way converter, motor/generator and generator Class equipment provides energy.
[0046] The battery provides short-term energy when the input power fails or is interrupted. Long-term power supply needs to start the diesel engine. The diesel engine starts when the battery is discharged. After the diesel engine starts normally, the battery stops supplying power, and the diesel engine drives the generator to provide power to the downstream equipment.
[0047] The hybrid uninterruptible power supply system according to the embodiment of the present invention provides timely and reliable uninterruptible power supply to the downstream load equipment through the use of rotating electromagnetic power equipment such as static bidirectional converters, batteries and motors, and ensures the safe operation of the downstream load equipment .
[0048] The hybrid uninterruptible power supply system according to the embodiment of the present invention has the following advantages: due to the application of a bidirectional converter, no separate battery charging circuit and discharging circuit are required; the generator and the motor/generator device are coaxially coupled, which can have synchronous adjustment Phase capacity; due to the use of motor/generator devices, any level of voltage conversion can be realized, making the system relatively high efficiency.
[0049] The hybrid uninterruptible power supply system described in the embodiment of the present invention is widely used. See Figure 4 , This figure is a schematic diagram of the application of the hybrid uninterruptible power supply system according to the embodiment of the present invention.
[0050] Figure 4 Shown is one of the application methods. The hybrid uninterruptible power supply system described in the embodiment of the present invention specifically provides power for the downstream medium-voltage input power distribution unit PDU (Power Distribution Unit), server, point of load (POL), etc. That is, the downstream load equipment is the downstream medium voltage input power distribution unit, server, and load point.
[0051] See Figure 5 , This figure is a schematic diagram of the connection between the hybrid uninterruptible power supply system and the peripheral circuit according to the embodiment of the present invention.
[0052] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a detection unit (to realize voltage and current detection) arranged between the fast power cut-off device and the input power source, and is used for sampling the front end of the fast power cut-off device Voltage signal and/or current signal.
[0053] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a controller connected to the detection unit, and the controller determines the input according to the voltage signal and/or current signal of the input power sampled by the detection unit When the power fails or the power is interrupted, quickly disconnect the path between the input power and the downstream load device; control the battery to discharge, and provide energy to the downstream load device through the two-way converter, motor/generator and generator .
[0054] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a generator connected to the generator, the motor/generator, and a motor/generator rotation speed detection unit. The generator, motor/generator speed detection unit sends the detected signal to the controller. The controller controls the operation state of the generator and the motor/generator according to the detected signal.
[0055] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a bidirectional converter current and voltage signal detection unit connected to the bidirectional converter.
[0056] The bidirectional converter current and voltage signal detection unit sends the detected signal to the controller. The controller controls the working state of the bidirectional converter according to the detected signal. When working in the rectifier mode, it charges the rear-stage battery, and when working in the inverter mode, the battery discharges.
[0057] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a battery voltage, temperature, and power detection unit connected to the battery.
[0058] The battery voltage, temperature, and power detection unit sends the detected signals to the controller. The controller controls the battery to work in a safe working range according to the above detected signal.
[0059] Since the two-way converter is a power electronic device with fast response speed, it can immediately provide energy to the downstream load equipment at the initial moment of input power failure. However, due to the low energy density of the battery, the stored energy can only maintain the running time of the downstream equipment from a few milliseconds to a few seconds. The specific maintenance time is related to the capacity of the battery and the size of the downstream load.
[0060] When the input power fails, the controller will send instructions to the diesel engine at the same time, such as Figure 5 Shown. The electric/generator drives the diesel engine through the clutch to make the diesel engine start smoothly. After the diesel engine starts normally, the battery stops discharging. The diesel engine provides power to the downstream equipment through the generator. Diesel engines and electric/generators belong to electromagnetic power equipment. The main components are magnetic components, so the dynamic response speed is slow. The diesel engine completes the startup process within the time when the battery supplies power to the load to provide energy to the downstream equipment. The role of the clutch is to make the diesel engine and the electric motor/generator work together and smoothly to avoid damage to the diesel engine and electric/generator due to shock.
[0061] The periphery of the hybrid uninterruptible power supply system of the present invention may further include a filtering device provided at the output end of the system.
[0062] The filtering device may specifically be a filter composed of an inductor and a capacitor.
[0063] The filtering device can also use software filtering in the control software to filter out certain harmonics.
[0064] For occasions with stricter requirements on output quality, you can consider setting up a frequency correction device at the output end of the system. By detecting the phase of the output signal of the system, comparing it with a reference signal and controlling it, the frequency correction device can output a signal. The frequency meets the actual needs of the downstream load equipment.
[0065] The hybrid uninterruptible power supply system according to the embodiment of the present invention may further include a grid voltage undervoltage and overvoltage protection device connected to the input power source for protection in the case of grid voltage undervoltage and overvoltage.
[0066] According to different control schemes, the voltage signal and current signal of the FUD front end can be sampled separately, or voltage and current signals can be sampled at the same time, the speed of the generator, motor/generator and other signals, the current and voltage signals of the bidirectional converter, and the battery Signals such as voltage, temperature, and electric quantity are used in the controller to control the entire system. Through mathematical processing and logical judgment of the signals, control commands are issued to control diesel engines, generators, electric/generators, batteries and bidirectional converters. Actions. When the grid voltage is overvoltage and undervoltage, it will act in time to disconnect the FUD.
[0067] The hybrid uninterruptible power supply system described in the embodiment of the present invention can be used under different voltage systems, the working principle is similar, and the power level is not limited. Through the use of static two-way converters, batteries, motors and other rotating electromagnetic power equipment, it provides timely and reliable uninterrupted power to the downstream load to ensure the safe operation of the downstream load equipment.
[0068] The above are only the preferred embodiments of the hybrid uninterruptible power supply system of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and improvements can be made. Retouching, these improvements and retouching should also be regarded as the protection scope of the present invention.
