A UPS power supply system and control method with dynamic bypass and backup automatic switching device

Abstract

A UPS power system and control method with dynamic bypass and backup automatic switching device, the system includes a first AC power supply, a second AC power supply, a first battery, a second battery, a first UPS, a second UPS, a first switch, a second switch, a third switch, and a fourth switch; and also includes a backup automatic switching device; breaking through the parallel operation mode of traditional UPS devices, adjusting the structure of the traditional primary system, and connecting the backup automatic switching device between two UPS power supplies running in parallel, thereby ensuring the normal power consumption of users supplied by the UPS power supply. While solving the reliability of the uninterruptible power supply system, it also takes into account the safe and stable operation characteristics of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic operation control of electric power systems, and in particular to a UPS power supply system coordinated with a dynamic bypass and a standby automatic switching device. Background Art

[0002] UPS (Uninterruptible Power Supply) is a constant voltage and frequency power supply device with an energy storage device and an inverter as its main component. Its main function is to provide a stable, continuous and uninterrupted power supply device to computer network systems or other power and electronic equipment through the UPS system. With the rapid development of various advanced technologies such as information technology and computer technology, human beings have higher and higher requirements for the reliability of power supply systems and the quality of power, especially in computers, medical care and administration. The instability of grid voltage and frequency, instantaneous or long-term interruption of power supply will cause equipment operation interruption, data loss and even hardware damage, leading to system paralysis and causing significant losses. The best way to solve the power supply problem is to use UPS. When the mains power is input normally, the UPS power supply stabilizes the mains power and supplies it to the load, and charges the battery pack inside the UPS; when the mains power is interrupted, the UPS detects this signal and is immediately put into use, that is, the battery pack inside the UPS converts DC into sinusoidal AC through the inverter to supply the load. At present, in the design and manufacture of UPS, due to the use of intelligent monitoring and IGBT (insulated gate transistor) modules and other high-tech, the failure rate of UPS has been greatly reduced, and the mean time between failures (MTBF) of large and medium-sized UPS has reached 200,000-250,000 hours. Therefore, from the perspective of the UPS equipment itself, its reliability is very high. However, there are inherent defects when a single power supply is used. Once a failure occurs, it may cause the system to paralyze and cause immeasurable losses.

[0003] In current uninterruptible power supply systems, inverter power supply parallel technology is often used to improve the reliability of UPS power supply system operation and expand the power supply capacity. At this time, the phase, frequency and amplitude of the output voltage of each UPS must be consistent, and the UPS in the UPS parallel system must be in a state of evenly sharing the load voltage, otherwise a circulating current will be generated between the UPS in the system; synchronous communication lines must be connected between each UPS. Once the synchronous line fails or is interrupted, the entire UPS device will lose step, causing the inverter circuit to burn out. Summary of the invention

[0004] In order to solve the technical problems in the background technology, the present invention provides a UPS power system and control method with dynamic bypass and backup automatic switching device, breaking through the parallel operation mode of traditional UPS devices, adjusting the structure of the traditional primary system, and connecting the backup automatic switching device between two UPS power supplies running in parallel, thereby ensuring the normal power consumption of users supplied by the UPS power supply. While solving the reliability of the uninterruptible power supply system, it also takes into account the safe and stable operation characteristics of the system.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A UPS power system with dynamic bypass and automatic backup device, comprising a first AC power source, a second AC power source, a first battery, a second battery, a first UPS, a second UPS, a first switch, a second switch, a third switch, and a fourth switch; and also comprising an automatic backup device;

[0007] The connection structure of the primary system of the UPS power supply system is as follows:

[0008] The AC input port of the first UPS is connected to a first AC power source, and the DC input port is connected to a first battery;

[0009] The AC input port of the second UPS is connected to a second AC power source, and the DC input port is connected to a second battery;

[0010] The output end of the first UPS is connected to the first power supply bus, the first switch is connected between the output end of the first UPS and the first power supply bus, the output end of the second UPS is connected to the second power supply bus, the second switch is connected between the output end of the second UPS and the second power supply bus, and the backup automatic switching device is connected between the first power supply bus and the second power supply bus;

[0011] The second AC power source also serves as a bypass power source for the first UPS and is connected to the first power supply bus via a third switch. The first AC power source also serves as a bypass power source for the second UPS and is connected to the second power supply bus via a fourth switch.

[0012] The output end of the first UPS is further provided with a first voltage sensor, and the output end of the second UPS is further provided with a second voltage sensor.

[0013] Furthermore, the first switch, the second switch, the third switch and the fourth switch are circuit breakers.

[0014] Furthermore, the first battery and the second battery have the same structure, both comprising 50 24V, 20MWh batteries, 5 batteries are connected in parallel to form 10 groups, and then these 10 groups are connected in series to form an overall battery pack.

[0015] Furthermore, the DC power supply port and AC input port of the first UPS and the second UPS are also provided with voltage sensors.

[0016] A switching control method for a UPS power system with dynamic bypass and backup automatic switching devices, comprising the following:

[0017] 1. When the total load does not exceed the set ratio of a single UPS, the standby automatic transfer device will be put into operation first:

[0018] 1) When the first voltage sensor has no signal output, the first switch K1 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply;

[0019] 2) When the second voltage sensor has no signal output, the second switch K2 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0020] 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected. At this time, it is more stable to put the third switch K3 and the fourth switch K4 into operation. The first UPS and the second UPS are completely bypassed, and the backup automatic switching device should be kept in the open state and cannot be locked;

[0021] 2. When the total load exceeds the set ratio of a single UPS, the bypass is put into operation first:

[0022] 1) When the first voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0023] 2) When the second voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0024] 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected, and the third switch K3 and the fourth switch K4 are switched on. Bypass the first UPS and the second UPS. If one of the third switch K3 and the fourth switch K4 cannot be switched on:

[0025] ① If there is output after the first UPS bypasses, the fourth switch K4 is cut off and the backup automatic transfer device is put into operation;

[0026] ② If there is output after the second UPS bypass, cut off the third switch K3 and activate the backup automatic transfer device.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1) The present invention breaks through the parallel operation mode of traditional UPS devices, adjusts the structure of the traditional primary system, and connects a backup automatic switch device between two UPS power supplies running in parallel. When the mains power and DC battery of one UPS fail, the backup automatic switch device can be quickly put into operation; when the total load at the time of failure does not exceed a certain proportion of a single UPS, the backup automatic switch device is first put into operation. If the total load at the time of failure exceeds a certain proportion of the single machine load, the bypass power supply is started first. When the bypass of the faulty UPS cannot be put into operation, the backup automatic switch device is put into operation. At the same time, the other UPS is bypassed, thereby ensuring the normal power consumption of users supplied by the UPS power supply. While solving the reliability of the uninterruptible power supply system, the safe and stable operation characteristics of the system are taken into account.

[0029] 2) In this power supply system, the first AC input source also serves as the input of the UPS2 bypass, and the second AC input source serves as the input of the UPS1 bypass, thereby forming a structure in which a UPS is associated with three power supply points, namely, AC input 1, AC input 2 and DC 1. At the same time, a backup automatic transfer device is connected to the output ends of the two UPSs, thereby forming an uninterruptible power supply system in which the backup automatic transfer device and the dynamic bypass cooperate, thereby improving its power supply reliability.

[0030] 3) The battery pack structure of this power system is more complicated than the previous battery pack wiring. For example, a normal battery pack is a structure of 10 24V batteries in a string, and the capacity of each battery is relatively large, thus forming a large battery pack. The battery pack structure of this power system is to split the 24V, 100MWh battery into 5 20MWh batteries in parallel, and the voltage at both ends remains unchanged at 24V. At this time, the number of batteries in the battery pack has increased from the original 10 to 50. In this case, when a battery in the battery pack is damaged and the internal resistance increases, it will not affect the change of the voltage of the entire battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a connection structure diagram of a primary system of a UPS power supply system of the present invention;

[0032] Figure 2 It is a secondary connection diagram of the UPS power supply system of the present invention;

[0033] Figure 3 It is a battery pack connection structure diagram of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation modes provided by the present invention are described in detail below with reference to the accompanying drawings.

[0035] like Figure 1 As shown, a UPS power system with dynamic bypass and automatic backup device includes a first AC power supply, a second AC power supply, a first battery, a second battery, a first UPS, a second UPS, a first switch K1, a second switch K2, a third switch K3, a fourth switch K4, and also includes an automatic backup device.

[0036] The connection structure of the primary system of the UPS power supply system is as follows:

[0037] The AC input port of the first UPS is connected to a first AC power source, and the DC input port is connected to a first battery;

[0038] The AC input port of the second UPS is connected to a second AC power source, and the DC input port is connected to a second battery;

[0039] The output end of the first UPS is connected to the first power supply bus, the first switch K1 is connected between the output end of the first UPS and the first power supply bus, the output end of the second UPS is connected to the second power supply bus, the second switch K2 is connected between the output end of the second UPS and the second power supply bus, and the backup automatic switching device is connected between the first power supply bus and the second power supply bus;

[0040] The second AC power source also serves as a bypass power source for the first UPS and is connected to the first power supply bus via the third switch K3. The first AC power source also serves as a bypass power source for the second UPS and is connected to the second power supply bus via the fourth switch K4.

[0041] The first switch K1, the second switch K2, the third switch K3, and the fourth switch K4 are circuit breakers.

[0042] like Figure 3 As shown, the first battery and the second battery have the same structure, both including 50 24V, 20MWh batteries, 5 batteries are connected in parallel to form 10 groups, and then these 10 groups are connected in series to form an overall battery pack.

[0043] The output end of the first UPS is also provided with a first voltage sensor PT1, and the output end of the second UPS is also provided with a second voltage sensor PT2. As output monitoring of the first UPS and the second UPS, it is used to monitor whether the first UPS and the second UPS fail to output.

[0044] The DC power supply port and AC input port of the first UPS and the second UPS are also provided with voltage sensors.

[0045] like Figure 2 As shown, the secondary part of the power supply system of the present invention has the control and adjustment function of the acquisition control terminal, and the central processing unit (PLC or industrial computer) analyzes the information collected by the first voltage sensor PT1 and the second voltage sensor PT2 to determine the linkage status of each switch. The switching control method of the UPS power supply system of the present invention includes the following:

[0046] 1. When the total load does not exceed the set ratio of a single UPS (generally 70-80%), the backup automatic transfer device will be put into operation first:

[0047] 3) When the first voltage sensor has no signal output, the first switch K1 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply;

[0048] 4) When the second voltage sensor has no signal output, the second switch K2 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0049] 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected. At this time, it is more stable to put the third switch K3 and the fourth switch K4 into operation. The first UPS and the second UPS are completely bypassed, and the backup automatic switching device should be kept in the open state and cannot be locked;

[0050] 2. When the total load exceeds the set ratio of a single UPS (generally 70-80%), the bypass is put into operation first:

[0051] 1) When the first voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0052] 2) When the second voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply;

[0053] 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected, and the third switch K3 and the fourth switch K4 are switched on. Bypass the first UPS and the second UPS. If one of the third switch K3 and the fourth switch K4 cannot be switched on, then:

[0054] ① If the first UPS has output after bypassing and the second UPS has no output, the fourth switch K4 is cut off and the standby automatic transfer device is put into operation;

[0055] ② If the second UPS has output after bypassing and the first UPS has no output, the third switch K3 is cut off and the backup automatic transfer device is put into operation.

[0056] The central processor of the present invention also analyzes the inside of each UPS through the voltage sensors of the DC power supply port and AC input port of the first UPS and the second UPS, and reports the UPS and its specific modules with problems, such as inverter failure, rectifier failure, etc., and the problem can be reflected according to the digital information and analog information collected by the collection terminal, such as voltage drop, rectifier self-test information, fault or location information. The central processing server collects data from the first UPS and the second UPS terminals, analyzes the collected data, finds out the specific fault point, and gives safety measures and the final processing method, and finally forms decision-making information to be transmitted to the control host.

[0057] The above embodiments are implemented based on the technical solution of the present invention, and detailed implementation methods and specific operation processes are given, but the protection scope of the present invention is not limited to the above embodiments. The methods used in the above embodiments are conventional methods unless otherwise specified.

Claims

1. A UPS power system with dynamic bypass and backup automatic switching device, characterized in that: It includes a first AC power supply, a second AC power supply, a first battery, a second battery, a first UPS, a second UPS, a first switch, a second switch, a third switch, and a fourth switch; and also includes a standby automatic switching device; The connection structure of the primary system of the UPS power supply system is as follows: The AC input port of the first UPS is connected to a first AC power source, and the DC input port is connected to a first battery; The AC input port of the second UPS is connected to a second AC power source, and the DC input port is connected to a second battery; The output end of the first UPS is connected to the first power supply bus, the first switch is connected between the output end of the first UPS and the first power supply bus, the output end of the second UPS is connected to the second power supply bus, the second switch is connected between the output end of the second UPS and the second power supply bus, and the backup automatic switching device is connected between the first power supply bus and the second power supply bus; The second AC power source also serves as a bypass power source for the first UPS and is connected to the first power supply bus via a third switch. The first AC power source also serves as a bypass power source for the second UPS and is connected to the second power supply bus via a fourth switch. The output end of the first UPS is further provided with a first voltage sensor, and the output end of the second UPS is further provided with a second voltage sensor.

2. A UPS power supply system with dynamic bypass and backup automatic switching device according to claim 1, characterized in that: The first switch, the second switch, the third switch and the fourth switch are circuit breakers.

3. A UPS power supply system with dynamic bypass and backup automatic switching device according to claim 1, characterized in that: The first battery and the second battery have the same structure, both comprising 50 24V, 20MWh batteries, 5 batteries each being connected in parallel to form 10 groups, and then these 10 groups are connected in series to form an overall battery pack.

4. A UPS power supply system with dynamic bypass and backup automatic switching device according to claim 1, characterized in that: The DC power supply port and AC input port of the first UPS and the second UPS are also provided with voltage sensors.

5. The switching control method of a UPS power system with dynamic bypass and backup automatic switching device according to claim 1 is characterized in that: These include:

1. When the total load does not exceed the set ratio of a single UPS, the standby automatic transfer device will be put into operation first: 1) When the first voltage sensor has no signal output, the first switch K1 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply; 2) When the second voltage sensor has no signal output, the second switch K2 is disconnected, and the backup automatic switching device is switched on first. If the backup automatic switching device cannot be switched on, the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply; 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected. At this time, it is more stable to put the third switch K3 and the fourth switch K4 into operation. The first UPS and the second UPS are completely bypassed, and the backup automatic switching device should be kept in the open state and cannot be locked; 2. When the total load exceeds the set ratio of a single UPS, the bypass is put into operation first: 1) When the first voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply; 2) When the second voltage sensor has no signal output, the first switch K1 is disconnected, the third switch K3 is closed, and the first UPS is bypassed by the second AC power supply. If the bypass cannot be switched, the backup automatic switching device is switched on. In order to prevent the load from exceeding 70% of the single machine load, the second switch K2 is disconnected again, and the fourth switch K4 is closed, and the second UPS is bypassed by the first AC power supply; 3) When the first voltage sensor and the second voltage sensor have no signal output, the first switch K1 and the second switch K2 are disconnected, and the third switch K3 and the fourth switch K4 are turned on, and the first UPS and the second UPS are bypassed. If one of the third switch K3 and the fourth switch K4 cannot be turned on: ① If there is output after the first UPS bypasses, the fourth switch K4 is cut off and the backup automatic transfer device is put into operation; ② If there is output after the second UPS bypass, cut off the third switch K3 and activate the backup automatic transfer device.

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