Quick-start uninterruptible power supply system control method

Abstract

The invention relates to a quick-start uninterruptible power supply system control method, belongs to the technical field of uninterruptible power supplies, and solves the problem that an uninterruptible power supply cannot supply power to a load in time in the prior art. The control method comprises the steps that real-time voltage input by the mains supply is directly used for supplying power to a load, and meanwhile, a transformation starting signal and a mains supply synchronizing signal are sent to the alternating-current uninterruptible power supply combination; after receiving the voltage transformation starting signal, the AC uninterruptible power supply combination rectifies and inverts the real-time voltage input by the commercial power to obtain an inversion output voltage, and when the inversion output voltage meets the stable output condition, the phase of the inversion output voltage is adjusted according to the commercial power synchronizing signal to obtain the stable output voltage. Therefore, the phase of the inversion output voltage is synchronized with the phase of the commercial power, and the mode of supplying power to the load from the real-time voltage input by the commercial power is switched to the mode of supplying power to the load by the inversion output voltage. And rapid power supply for the load is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of uninterrupted power supply, in particular to a control method of an uninterrupted power supply system with fast start-up. BACKGROUND

[0002] In today's society, people are increasingly dependent on electricity, and the role of uninterrupted power supply systems is becoming increasingly important. Uninterrupted power supply systems have the following advantages:

[0003] ① Ensure the stable operation of load devices and protect them from external conditions such as abnormal mains power;

[0004] ② Protect load devices from harmonics;

[0005] ③ Automatic switching;

[0006] ④ Prolong the service life of load devices;

[0007] ⑤ Protect important data.

[0008] Uninterrupted power supply systems not only need seamless switching, but also need to have the function of fast start-up. How to reduce the start-up time of uninterrupted power supply systems is a pressing problem. Currently, there are two main methods to improve the start-up time of alternating current uninterrupted power supply systems:

[0009] One is to adjust the control parameters to improve the response rate of the uninterrupted power supply system;

[0010] The second is to adjust the slow start-up parameters to reduce the threshold of the bus voltage slow start-up.

[0011] These two methods can reduce the start-up time of the uninterrupted power supply system to a certain extent, but the adjustment range is limited and cannot fundamentally and significantly solve the problem of long start-up time of the uninterrupted power supply system. The above two methods excessively pursue the response rate of the uninterrupted power supply system and the lifting speed of the bus voltage, which is not conducive to the stable operation of the uninterrupted power supply system.

[0012] Therefore, there is an urgent need for a technical solution for an uninterrupted power supply system that can respond quickly to loads. SUMMARY

[0013] In view of the above analysis, the embodiments of the present application aim to provide a control method of an uninterrupted power supply system with fast start-up to solve the problem that the uninterrupted power supply in the prior art cannot supply power to the load in time.

[0014] The embodiments of the present application provide a control method of an uninterrupted power supply system with fast start-up, which includes a bypass switching combination and an alternating current uninterrupted power supply combination, and the control method comprises:

[0015] The bypass switching combination directly supplies the real-time voltage of the mains input to the load when receiving the mains input, and sends a start-transform signal and a mains synchronization signal to the AC UPS combination;

[0016] The AC UPS combination rectifies and inverts the real-time voltage of the mains input to obtain an inverted output voltage after receiving the start-transform signal, judges whether the inverted output voltage meets a stable output condition, and adjusts the phase of the inverted output voltage according to the mains synchronization signal to synchronize the phase of the inverted output voltage with the phase of the mains when the inverted output voltage meets the stable output condition.

[0017] The real-time voltage of the mains input is switched to the inverted output voltage for supplying the load when the phase of the inverted output voltage is synchronized with the phase of the mains.

[0018] Based on the further improvement of the control method, the bypass switching combination comprises a first DSP controller, a first switch S1 and a second switch S2.

[0019] The mains is connected to the load through the first switch S1, and the AC UPS combination is connected to the load through the second switch S2.

[0020] The first DSP controller selects the mains or the inverted output voltage of the AC UPS combination output for supplying the load by controlling the conduction and turn-off of the first switch S1 and the second switch S2.

[0021] Based on the further improvement of the control method, the bypass switching combination further comprises a differential circuit and a zero-crossing comparator, and the mains synchronization signal is generated by the following steps:

[0022] The differential circuit and the zero-crossing comparator are used to detect the positive and negative zero voltage points of the AC power input of the mains to generate a square wave signal synchronized with the zero-crossing point of the mains.

[0023] The square wave signal is sent to the CAP capture interface of the first DSP controller, and the rising edge of the square wave signal is detected by the CAP capture interface to trigger a capture interrupt, and the IO port outputs the mains synchronization signal in phase with the zero-crossing point of the AC power input of the mains in the capture interrupt.

[0024] Based on the further improvement of the control method, the real-time voltage of the mains input is rectified and inverted to obtain an inverted output voltage, and whether the inverted output voltage meets a stable output condition is judged, which comprises:

[0025] A plurality of inverted output voltages in a preset time period before the current time point are collected to judge whether the plurality of inverted output voltages are in a stable output voltage range.

[0026] When the plurality of inverter output voltages are all within the stable output voltage range, the inverter output voltage satisfies the stable output condition.

[0027] Based on the further improvement of the above control method, the alternating current uninterruptible power supply combination comprises a second DSP controller, a rectifier circuit and an inverter circuit.

[0028] The second DSP controller receives the start voltage signal and the mains synchronization signal sent by the first DSP controller.

[0029] The second DSP controller controls the rectifier circuit and the inverter circuit to rectify and invert the alternating current input from the mains according to the start voltage signal, so as to obtain the inverter output voltage.

[0030] Based on the further improvement of the above control method, the rectifier circuit comprises a power inductor L1, a first diode D1, a second diode D2, a first capacitor C1 and a second capacitor C2, a first switch tube V1 and a second switch tube V2.

[0031] One end of the power inductor L1 is used as the input end of the rectifier circuit, and is used for receiving the alternating current input from the mains.

[0032] The other end of the power inductor L1 is connected to the anode of the first diode D1, the cathode of the second diode D2 and the emitter of the first switch tube V1; the collector of the first switch tube V1 is connected to the collector of the second switch tube V2.

[0033] The cathode of the first diode D1 is used as the anode of the DC bus, and is connected to one end of the first capacitor C1.

[0034] The anode of the second diode D2 is used as the cathode of the DC bus, and is connected to one end of the second capacitor C2.

[0035] The other end of the first capacitor C1, the other end of the second capacitor C2 and the emitter of the second switch tube V2 are connected and used as the zero end of the DC bus.

[0036] Based on the further improvement of the above control method, the inverter circuit comprises a filter inductor L2, a filter capacitor C5, a third capacitor C3, a fourth capacitor C4, a third switch tube V3, a fourth switch tube V4, a fifth switch tube V5 and a sixth switch tube V6.

[0037] One end of the third capacitor C3 is connected to the anode of the DC bus and the collector of the third switch tube V3; the other end of the third capacitor C3 is connected to the zero end of the DC bus, one end of the fourth capacitor C4 and the emitter of the fifth switch tube V5; the collector of the fifth switch tube V5 is connected to the collector of the sixth switch tube V6.

[0038] One end of the fourth capacitor C4 is connected to the negative pole of the DC bus, and the emitter of the fourth switch tube V4; the collector of the fourth switch tube V4 is connected to the emitter of the third switch tube V3, the emitter of the sixth switch tube V6 and one end of the filter inductor L2;

[0039] The other end of the filter inductor L2 is the output end of the inverter circuit, and is connected to one end of the filter capacitor C5; the other end of the filter capacitor C5 is connected to the zero pole of the DC bus.

[0040] Based on the further improvement of the above control method, the second DSP controller adjusts the phase of the inverter output voltage according to the mains synchronization signal, specifically including:

[0041] Calculate the real-time phase difference value of the mains synchronization signal and the inverter output voltage, and determine whether the real-time phase difference value meets the set error;

[0042] If not, adjust the duty cycle of the third switch tube V3 to the sixth switch tube V6 based on the controller until the real-time phase difference value meets the set error; at the same time, turn off the fourth switch tube V4 when adjusting the duty cycle of the third switch tube V3, and turn off the third switch tube V3 when adjusting the duty cycle of the fourth switch tube V4;

[0043] Among them, the fifth switch tube V5 and the third switch tube V3 have opposite switching states, and the sixth switch tube V6 and the fourth switch tube V4 have opposite switching states.

[0044] Based on the further improvement of the above control method, the adjustment of the duty cycle of the third switch tube V3 and the fourth switch tube V4 based on the controller includes:

[0045] The transfer function of the inverter circuit switch tube duty cycle and the inverter output voltage phase is compensated by using a switching power supply III type compensator;

[0046] The switching power supply III type compensator includes two zeros and three poles.

[0047] Based on the further improvement of the above control method, the two zeros and three poles of the switching power supply III type compensator are determined by the following steps:

[0048] The transfer function Bode diagram of the duty cycle of the third switch tube V3, the fourth switch tube V4, the fifth switch tube V5 and the sixth switch tube V6 of the inverter circuit and the inverter output voltage phase is obtained by simulation, and one conjugate pole ω p0 And one zero ω z0 ;

[0049] Then the two zeros and three poles of the switching power supply III type compensator are determined by the following formula:

[0050]

[0051] ω p1 = 0, ω p2 = ω z0 ,

[0052] wherein ω z1 , ω z2 represent two zero points, ω p1 , ω p2 and ω p3 represent three pole points, and ω p represents the angular frequency of the third switch V3.

[0053] Compared with the prior art, the present application can achieve at least the following beneficial effects:

[0054] 1. When receiving the mains input through the bypass switching combination, the real-time voltage of the mains input is directly used to supply power to the load, thereby quickly supplying power to the load; meanwhile, it is judged whether the inverter output voltage of the alternating uninterruptible power supply meets the stable output condition, and after the stable output condition is met, the phase of the inverter output voltage is adjusted to be synchronized with the phase of the mains, thereby switching from the real-time voltage of the mains to the inverter output voltage for supplying power to the load, meeting the working response scene of the load with high startup time requirement and requiring fast power supply, and quickly supplying power to the load.

[0055] 2. The transfer function of the switching power supply III type compensator to the inverter circuit switch duty ratio and the inverter output voltage phase is compensated, the time for adjusting the phase of the inverter output voltage to be synchronized with the phase of the mains input alternating current by the controller is shortened, the inverter output voltage can be used to supply power to the load as soon as possible, and the stability of the uninterruptible power supply system is improved.

[0056] In the present application, the above technical solutions can be combined with each other to realize more preferred combination solutions. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification or be understood by implementing the present application. The purposes and other advantages of the present application can be realized and obtained from the contents specifically indicated in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0057] The accompanying drawings are included to provide a further understanding of the present application and are incorporated in and constitute a part of this specification, illustrate embodiments of the present application and serve to explain the principles of the present application.

[0058] Figure 1 A flowchart of a fast-starting uninterruptible power supply system control method provided by the embodiments of the present application is shown in the figure.

[0059] Figure 2 Structure diagram of bypass switch combination provided by the embodiment of the present application;

[0060] Figure 3 Structure diagram of AC uninterruptible power supply combination provided by the embodiment of the present application;

[0061] Figure 4 Structure diagram of rectifier circuit provided by the embodiment of the present application;

[0062] Figure 5 Structure diagram of inverter circuit provided by the embodiment of the present application;

[0063] Figure 6 Control signal diagram of inverter circuit provided by the embodiment of the present application through third switch tube V3, fourth switch tube V4, fifth switch tube V5 and sixth switch tube V6;

[0064] Figure 7 Bode plot of transfer function of duty cycle of inverter circuit and phase of inverter output voltage when III type compensator of switching power supply is not added provided by the embodiment of the present application;

[0065] Figure 8 Bode plot of transfer function of duty cycle of inverter circuit and phase of inverter output voltage when III type compensator of switching power supply is added provided by the embodiment of the present application. DETAILED DESCRIPTION

[0066] The preferred embodiments of the present application will be described in detail below with reference to the drawings, which form a part of this application. The drawings and the associated descriptions are provided to illustrate the embodiments of the present application and to explain the principle of the present application, but are not intended to limit the scope of the present application.

[0067] The conventional method of reducing the starting time of the uninterruptible power supply system cannot fundamentally solve the problem, and has poor stability. In order to solve the problem of long starting time of the uninterruptible power supply system, the control method of the uninterruptible power supply system is improved and researched.

[0068] The present application controls the inverter input and the mains input, enters the bypass mode first and then enters the inverter mode when power on, and the seamless switching of the two modes can ensure that the input side can supply power to the load as soon as power on, and the output is uninterrupted, which lays the foundation for the fast power-on, fast arrangement and work of the entire system in specific occasions with high requirements for starting time and fast power supply.

[0069] One specific embodiment of the present application discloses a control method of an uninterruptible power supply system with fast starting, and the uninterruptible power supply system includes a bypass switch combination and an AC uninterruptible power supply combination, as shown in Figure 1 The control method includes:

[0070] Step S1: When the bypass switching combination receives the mains input, directly supply the real-time voltage of the mains input to the load, and send a start voltage conversion signal and a mains synchronization signal to the AC UPS combination;

[0071] Step S2: After receiving the start voltage conversion signal, the AC UPS combination rectifies and inverts the real-time voltage of the mains input to obtain an inverted output voltage, and judges whether the inverted output voltage meets the stable output condition; when the inverted output voltage meets the stable output condition, adjusts the phase of the inverted output voltage according to the mains synchronization signal, so that the phase of the inverted output voltage is synchronized with the phase of the mains;

[0072] Step S3: When the phase of the inverted output voltage is synchronized with the phase of the mains, switch from supplying the real-time voltage of the mains to the load to supplying the inverted output voltage to the load.

[0073] Specifically, as shown in Figure 1 , in step S1, when the mains input, through two lines, enters the bypass switching combination and the AC UPS combination in the uninterruptible power supply system at the same time. In the bypass switching combination, after confirming that the mains input is received, the real-time voltage of the mains input is directly input to the load to supply power to the load, so that the load quickly responds to work.

[0074] Specifically, in the bypass switching combination, after confirming that the mains input is received, a start voltage conversion signal and a mains synchronization signal are sent to the AC UPS combination.

[0075] Preferably, as shown in Figure 2 , the bypass switching combination includes a first DSP controller, a first switch S1 and a second switch S2;

[0076] The mains is connected to the load through the first switch S1, and the AC UPS combination is connected to the load through the second switch S2;

[0077] The first DSP controller selects the inverted output voltage output by the AC UPS combination or the mains to supply power to the load by controlling the conduction and shutdown of the first switch S1 and the second switch S2.

[0078] Specifically, as shown in Figure 2 , in the bypass switching combination, when the mains input, the first DSP controller can make the mains input directly input to the load by controlling the first switch S1. The inverted output voltage of the AC UPS combination is input to the second switch S2 through an inverter input port, and the bypass switching combination makes the inverted output voltage output by the AC UPS combination supply power to the load by controlling the conduction and shutdown of the second switch S2.

[0079] Preferably, the bypass switching combination further comprises a differential circuit and a zero-crossing comparator, and the mains synchronization signal is generated by the following steps:

[0080] The positive zero voltage point and the negative zero voltage point of the AC power input are detected by the differential circuit and the zero-crossing comparator to generate a square wave signal synchronized with the zero-crossing point of the AC power input;

[0081] The square wave signal is sent to the CAP capture interface of the first DSP controller, and a capture interrupt is triggered when the CAP capture interface detects the rising edge of the square wave signal, and in the capture interrupt, the IO port is controlled to output the mains synchronization signal in phase with the zero-crossing point of the AC power input.

[0082] Specifically, as shown in Figure 2 the bypass switching combination further comprises a differential circuit and a zero-crossing comparator, and the positive zero voltage point and the negative zero voltage point of the AC power input are detected by the differential circuit and the zero-crossing comparator to generate a square wave signal synchronized with the zero-crossing point of the AC power input. It can be understood that the positive zero voltage point refers to the point where the voltage changes from positive to zero, and the negative zero voltage point refers to the point where the voltage changes from negative to zero.

[0083] Specifically, the generated square wave signal is input to the CAP capture interface of the first DSP controller, and a capture interrupt is triggered when the CAP capture interface detects the rising edge of the square wave signal, and in the capture interrupt, the IO port is controlled to output the mains synchronization signal in phase with the zero-crossing point of the AC power input.

[0084] Specifically, as shown in Figure 1 in step S2, the AC UPS combination rectifies and inverts the real-time voltage of the AC power input to obtain an inverter output voltage after receiving the start voltage signal sent by the bypass switching combination, and judges whether the inverter output voltage meets the stable output condition. As shown in Figure 2 the first DSP controller generates the start voltage signal and the mains synchronization signal.

[0085] Preferably, rectifying and inverting the real-time voltage of the AC power input to obtain an inverter output voltage, and judging whether the inverter output voltage meets the stable output condition, comprises:

[0086] Collecting a plurality of inverter output voltages in a preset time period before the current time point, and judging whether the plurality of inverter output voltages are within the stable output voltage range;

[0087] When the plurality of inverter output voltages are all within the stable output voltage range, the inverter output voltage meets the stable output condition.

[0088] Specifically, the AC uninterruptible power supply combination rectifies, inverts the AC power input, and determines whether the inverted output voltage meets the stable output condition. It is worth noting that the stable output condition is that the inverted output voltage can continuously output stable voltage, AC power with small amplitude and few harmonics. In this way, whether the multiple inverted output voltages in a preset time period before the current time point are within the stable output voltage range is determined. The stable output voltage range and the preset time period need to be reasonably set according to actual conditions.

[0089] It is worth noting that when the multiple inverted output voltages are all within the stable output voltage range, the inverted output voltage meets the stable output condition.

[0090] Preferably, the AC uninterruptible power supply combination comprises a second DSP controller, a rectifier circuit and an inverter circuit.

[0091] The second DSP controller receives the start voltage signal and the AC power synchronization signal sent by the first DSP controller.

[0092] The second DSP controller controls the rectifier circuit and the inverter circuit to rectify and invert the AC power input according to the start voltage signal, to obtain the inverted output voltage.

[0093] Specifically, as shown in Figure 3 The second DSP controller receives the start voltage signal and the AC power synchronization signal sent by the first DSP controller, and controls the rectifier circuit and the inverter circuit to rectify and invert the AC power input according to the start voltage signal, to obtain the inverted output voltage. The inverted output voltage is transmitted to the inverter input port of the bypass switching combination through the inverter output port.

[0094] Figure 4 Preferably, as shown in

[0095] The one end of the power inductor L1 is used as the input end of the rectifier circuit, for receiving the AC power input.

[0096] The other end of the power inductor L1 is connected to the anode of the first diode D1, the cathode of the second diode D2 and the emitter of the first switch V1. The collector of the first switch V1 is connected to the collector of the second switch V2.

[0097] The cathode of the first diode D1 is used as the anode of the DC bus, and is connected to one end of the first capacitor C1.

[0098] The anode of the second diode D2 is used as the cathode of the DC bus, and is connected to one end of the second capacitor C2. ​​​​​​​​​​​​

[0099] The other end of the first capacitor C1, the other end of the second capacitor C2, and the emitter of the second switching transistor V2 are connected and serve as the zero pole of the DC bus.

[0100] Specifically, such as Figure 4 As shown, the mains power input is fed into the rectifier circuit through the power inductor L1. In the rectifier circuit, the first diode D1, the second diode D2, the first capacitor C1 and the second capacitor C2, the first switch V1 and the second switch V2 work together to output the DC bus from the +BUS and -BUS ports. The N port serves as the zero terminal of the DC bus. That is, the successfully rectified DC bus voltage is output to the inverter circuit through the +BUS, -BUS and N ports of the rectifier circuit.

[0101] Preferably, such as Figure 5 As shown, the inverter circuit includes a filter inductor L2, a filter capacitor C5, a third capacitor C3, a fourth capacitor C4, a third switch V3, a fourth switch V4, a fifth switch V5, and a sixth switch V6.

[0102] One end of the third capacitor C3 is connected to the positive terminal of the DC bus and also to the collector of the third switch V3; the other end of the third capacitor C3 is connected to the zero terminal of the DC bus and also to one end of the fourth capacitor C4 and the emitter of the fifth switch V5; the collector of the fifth switch V5 is connected to the collector of the sixth switch V6.

[0103] One end of the fourth capacitor C4 is connected to the negative terminal of the DC bus and also to the emitter of the fourth switch V4; the collector of the fourth switch V4 is connected to the emitter of the third switch V3, the emitter of the sixth switch V6, and one end of the filter inductor L2.

[0104] The other end of the filter inductor L2 serves as the output terminal of the inverter circuit and is also connected to one end of the filter capacitor C5. The other end of the filter capacitor C5 is connected to the zero pole of the DC bus.

[0105] Specifically, such as Figure 5 As shown, the +BUS, -BUS, and N ports of the inverter circuit are connected to the corresponding +BUS, -BUS, and N ports of the rectifier circuit. The inverter circuit converts the DC bus voltage into AC voltage and outputs it through port O2.

[0106] Specifically, such as Figure 6 As shown, G3 is the control signal for the third switch V3, G4 is the control signal for the fourth switch V4, G5 is the control signal for the fifth switch V5, G6 is the control signal for the sixth switch V6, and Uo 1N for Figure 5 The output voltage signal at point o1, Uo 2N for Figure 5The output voltage signal of the o2 point.

[0107] The output voltage of the o1 point is adjusted by controlling the duty cycles of the third switch V3, the fourth switch V4, the fifth switch V5 and the sixth switch V6, and the inverter output voltage is output at the o2 point through filtering of the filter inductor L2 and the filter capacitor C5.

[0108] Preferably, the second DSP controller adjusts the phase of the inverter output voltage according to the mains synchronization signal, and the adjustment specifically includes:

[0109] calculating the real-time phase difference between the mains synchronization signal and the inverter output voltage, and determining whether the real-time phase difference meets the set error;

[0110] If not, adjusting the duty cycles of the third switch V3 to the sixth switch V6 based on the controller until the real-time phase difference meets the set error; and turning off the fourth switch V4 when adjusting the duty cycle of the third switch V3, and turning off the third switch V3 when adjusting the duty cycle of the fourth switch V4.

[0111] The fifth switch V5 and the third switch V3 have opposite switching states, and the sixth switch V6 and the fourth switch V4 have opposite switching states.

[0112] Specifically, at each adjustment, the phase difference between the mains output at the current time point and the inverter output voltage is determined first. If the real-time phase difference does not meet the set error, the duty cycles of the third switch V3, the fourth switch V4, the fifth switch V5 and the sixth switch V6 need to be adjusted to reduce the real-time phase difference at the next adjustment. Through multiple adjustments, the real-time phase difference meets the set error. It can be understood that the set error needs to be reasonably set in advance according to actual needs.

[0113] As shown in Figure 5 and Figure 6 When adjusting the duty cycles of the third switch V3, the fourth switch V4, the fifth switch V5 and the sixth switch V6, the fourth switch V4 is turned off when adjusting the duty cycle of the third switch V3, and the third switch V3 is turned off when adjusting the duty cycle of the fourth switch V4; the fifth switch V5 and the third switch V3 have opposite switching states, and the sixth switch V6 and the fourth switch V4 have opposite switching states.

[0114] Preferably, the adjusting of the duty cycles of the third switch V3 and the fourth switch V4 based on the controller includes:

[0115] The transfer function of the inverter circuit switch duty cycle and the inverter output voltage phase is compensated by the switching power supply III type compensator.

[0116] The switching power supply III type compensator includes two zero points and three poles.

[0117] Specifically, when the switching power supply III type compensator does not compensate the transfer function of the inverter circuit switch duty ratio and the inverter output voltage phase, the Bode diagram of the transfer function of the inverter circuit switch duty ratio and the inverter output voltage phase is as shown in Figure 7 ; the Bode diagram of the transfer function of the inverter circuit switch duty ratio and the inverter output voltage phase after adding the switching power supply III type compensator is as shown in Figure 8 .

[0118] It is worth noting that, in Figure 7 , there is a conjugate pole ωp0=1330 rad / s and a zero point ωz0=13537 rad / s in the low frequency band, and the phase margin is only 17 deg when the switching power supply III type compensator is not added; at the same time, the amplitude-frequency characteristic curve crosses the 0dB line at -40dB / dec, and the low frequency gain is low. In Figure 8 , the phase margin is 80.7° after adding the compensator, crosses the 0dB line at -20dB / dec, and the low frequency gain is improved, the system is stable, and can accelerate the synchronization adjustment of the phase of the inverter output voltage and the phase of the AC power supply.

[0119] Preferably, the two zero points and three poles of the switching power supply III type compensator are determined by the following steps:

[0120] The Bode diagram of the transfer function of the duty ratio of the third switch V3, the fourth switch V4, the fifth switch V5 and the sixth switch V6 of the inverter circuit and the phase of the inverter output voltage is obtained by simulation, and a conjugate pole ω p0 and a zero point ω z0 are determined according to the Bode diagram of the transfer function.

[0121] Then the two zero points and three poles of the switching power supply III type compensator are determined by the following formula:

[0122]

[0123] ω p1 =0, ω p2 =ω z0 ,

[0124] Wherein, ω z1 , ω z2 represent two zero points, ω p1 , ω p2 and ω p3 represent three poles, and ω pThe angular frequency of the third switch V3 is represented.

[0125] Specifically, the simulation can be performed by using a psim simulation software.

[0126] Compared with the prior art, the control method of the fast-starting uninterruptible power supply system provided by the embodiment directly supplies the real-time voltage of the mains input to the load for fast power supply to the load when the bypass switching combination receives the mains input; meanwhile, it is judged whether the inverter output voltage of the alternating-current uninterruptible power supply meets the stable output condition, and after the stable output condition is met, the phase of the inverter output voltage is adjusted to be synchronized with the phase of the mains, so that the real-time voltage of the mains input is switched to the inverter output voltage for power supply to the load, which meets the working response scene of the load with high startup time requirement and fast power supply requirement, and fast power supply is performed to the load; meanwhile, the transfer function of the duty cycle of the inverter circuit switch and the phase of the inverter output voltage is compensated by the switching power supply III type compensator, the time for adjusting the phase of the inverter output voltage to be synchronized with the phase of the alternating current of the mains input is shortened, the inverter output voltage can be used to supply power to the load as soon as possible, and the stability of the uninterruptible power supply system is improved.

[0127] Those skilled in the art can understand that all or part of the processes of the above-mentioned embodiments can be completed by a computer program instructing related hardware, and the program can be stored in a computer readable storage medium, wherein the computer readable storage medium is a disk, an optical disk, a read-only memory or a random access memory, etc.

[0128] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A fast-start uninterruptible power supply system control method, characterized by, The control method comprises the following steps: When the bypass switching combination receives the mains input, the real-time voltage of the mains input is directly supplied to the load, and a start voltage conversion signal and a mains synchronization signal are sent to the AC UPS combination; After receiving the start voltage conversion signal, the AC UPS combination rectifies and inverts the real-time voltage of the mains input to obtain an inverted output voltage, judges whether the inverted output voltage meets a stable output condition, and adjusts the phase of the inverted output voltage according to the mains synchronization signal to synchronize the phase of the inverted output voltage with the phase of the mains when the inverted output voltage meets the stable output condition; When the phase of the inverted output voltage is synchronized with the phase of the mains, the real-time voltage of the mains is switched to the inverted output voltage to supply power to the load.

2. The control method according to claim 1, characterized by, The bypass switching combination comprises a first DSP controller, a first switch S1 and a second switch S2; The mains is connected to the load through the first switch S1, and the AC UPS combination is connected to the load through the second switch S2; The first DSP controller selects the inverted output voltage output by the AC UPS combination or the mains to supply power to the load by controlling the conduction and shutdown of the first switch S1 and the second switch S2.

3. The control method according to claim 2, characterized by, The bypass switching combination further comprises a differential circuit and a zero-crossing comparator, and the mains synchronization signal is generated through the following steps: The differential circuit and the zero-crossing comparator are used to detect the positive zero voltage point and the negative zero voltage point of the AC power input to generate a square wave signal synchronized with the zero-crossing point of the mains; The square wave signal is sent to the CAP capture interface of the first DSP controller; when the CAP capture interface detects the rising edge of the square wave signal, a capture interrupt is triggered, and the mains synchronization signal in the same phase as the zero-crossing point of the mains input is output from the IO port in the capture interrupt.

4. The control method according to claim 3, characterized by, The real-time voltage of the mains input is rectified and inverted to obtain an inverted output voltage, and whether the inverted output voltage meets a stable output condition is judged, comprising: A plurality of inverted output voltages in a preset time period before the current time point are collected to judge whether the plurality of inverted output voltages are within a stable output voltage range; When the plurality of inverted output voltages are all within the stable output voltage range, the inverted output voltage meets the stable output condition.

5. The control method according to claim 3, characterized by, The AC UPS combination comprises a second DSP controller, a rectifier circuit and an inverter circuit; The start voltage conversion signal and the mains synchronization signal sent by the first DSP controller are received by the second DSP controller; The second DSP controller controls the rectifier circuit and the inverter circuit to rectify and invert the AC power input according to the start voltage conversion signal to obtain an inverted output voltage.

6. The control method according to claim 5, characterized by, The rectifier circuit comprises a power inductor L1, a first diode D1, a second diode D2, a first capacitor C1 and a second capacitor C2, a first switch tube V1 and a second switch tube V2; One end of the power inductor L1 is used as the input end of the rectifier circuit to receive the AC power input by the mains; The other end of the power inductor L1 is connected to the anode of the first diode D1, the cathode of the second diode D2 and the emitter of the first switch V1; the collector of the first switch V1 is connected to the collector of the second switch V2; The cathode of the first diode D1 is connected to the anode of the DC bus and one end of the first capacitor C1; The anode of the second diode D2 is connected to the cathode of the DC bus and one end of the second capacitor C2; The other end of the first capacitor C1, the other end of the second capacitor C2 and the emitter of the second switch V2 are connected and serve as the zero terminal of the DC bus.

7. The control method according to claim 6, characterized by, The inverter circuit comprises a filter inductor L2, a filter capacitor C5, a third capacitor C3, a fourth capacitor C4, a third switch V3, a fourth switch V4, a fifth switch V5 and a sixth switch V6; One end of the third capacitor C3 is connected to the anode of the DC bus and the collector of the third switch V3; the other end of the third capacitor C3 is connected to the zero terminal of the DC bus, one end of the fourth capacitor C4 and the emitter of the fifth switch V5; the collector of the fifth switch V5 is connected to the collector of the sixth switch V6; One end of the fourth capacitor C4 is connected to the cathode of the DC bus and the emitter of the fourth switch V4; the collector of the fourth switch V4 is connected to the emitter of the third switch V3, the emitter of the sixth switch V6 and one end of the filter inductor L2; The other end of the filter inductor L2 serves as the output terminal of the inverter circuit and is connected to one end of the filter capacitor C5; the other end of the filter capacitor C5 is connected to the zero terminal of the DC bus.

8. The control method according to claim 6, characterized by, The second DSP controller adjusts the phase of the inverter output voltage according to the mains synchronization signal, specifically including: calculating the real-time phase difference between the mains synchronization signal and the inverter output voltage, and determining whether the real-time phase difference meets the set error; if not, adjusting the duty cycle of the third switch V3 to the sixth switch V6 based on the controller until the real-time phase difference meets the set error; at the same time, turning off the fourth switch V4 when adjusting the duty cycle of the third switch V3, and turning off the third switch V3 when adjusting the duty cycle of the fourth switch V4; wherein the switching state of the fifth switch V5 is opposite to that of the third switch V3, and the switching state of the sixth switch V6 is opposite to that of the fourth switch V4.

9. The control method according to claim 8, characterized by, The adjustment of the duty cycle of the third switch V3 and the fourth switch V4 based on the controller comprises: compensating the transfer function of the inverter circuit switch duty cycle and the inverter output voltage phase by using a switching power supply III type compensator; The switching power supply III type compensator comprises two zeros and three poles.

10. The control method according to claim 9, characterized by, The two zeros and three poles of the switching power supply III type compensator are determined by the following steps: The transfer function Bode chart of the duty cycle of the third switch V3, the fourth switch V4, the fifth switch V5 and the sixth switch V6 of the inverter circuit and the phase of the inverter output voltage is obtained through simulation, and according to the transfer function Bode chart, a conjugate pole ω p0 and a zero ω z0 are determined. The two zeros and three poles of the switching power supply III type compensator are determined by the following formula: where ω z1 , ω z2 represents two zeros, ω p1 , ω p2 and ω p3 represent three poles, and ω p represents the angular frequency of the third switch V3.

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