Generator set zero power failure transfer device and method

Abstract

The invention discloses a generator set zero-power-failure transfer device and method, and belongs to the technical field of power distribution networks, the generator set zero-power-failure transfer device comprises a control module and an energy storage power supply, the input end of the control module is connected with the energy storage power supply and a generator set, and the output end of the control module is connected with a power distribution cabinet on the power grid side; the control module comprises a main control unit, a line switching module, an electric energy conversion module and a voltage and current acquisition module, detects the voltage, frequency and phase of the output side and the power grid side of the generator set, and controls the voltage and current output by the energy storage power supply according to a detected signal; and the energy storage power supply is used as a conversion medium to complete load transfer of the generator set and the power grid side under zero power failure. Through the synergistic effect of the control module, the energy storage power supply and the generator set, grid connection and grid disconnection of the generator set are completed by connecting a group of cables, and the problem of power grid impact caused by mismatching of phases, voltages and frequencies is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power distribution network, in particular to a generator set zero power transfer device and method. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] The reliability and continuity of power supply have become an important standard for measuring the level of modern power service. Uninterrupted operation has important economic, social and technical significance. For large power users such as industrial enterprises, data centers and commercial complexes, power outage means production stagnation, data loss or business loss. Uninterrupted operation can avoid economic losses caused by planned power outages, especially for high-end manufacturing, semiconductor industry and other industries with high requirements for power quality. The promotion of uninterrupted operation has prompted power grid companies to continuously develop new technologies and new equipment, such as live working robots, unmanned intelligent inspection, flexible cable bypass systems, etc., improving operation efficiency and safety. At the same time, the application of this technology also promotes the development of power distribution network automation and intelligent operation and maintenance, making power grid management more refined and intelligent. For example, some provinces of State Grid have achieved more than 90% of uninterrupted operation of distribution network operation, and have expanded to higher voltage levels, gradually forming an uninterrupted operation system of "full voltage and full type". Uninterrupted operation of power grid is not only a manifestation of technological progress, but also an important measure to improve power supply service quality and support economic and social development. In the future, with the in-depth application of intelligent and automated technologies, uninterrupted operation will further expand to higher voltage levels and more complex scenarios, providing a solid guarantee for building a world-class power grid.

[0004] Currently, low-voltage power generation vehicles are gradually used for temporary power supply for loads during maintenance, but this scheme requires temporary power outage of the load and cannot guarantee zero power transfer for the load. Some generator sets of the power generation vehicles are provided with a grid-connected module to ensure zero power outage by generating power in parallel with the grid, but the grid-connected environment requires a set of cables (a total of 8 cables) to be connected to the power supply and the load side, which is a large amount of work, and it is difficult to find suitable connection positions, often resulting in failure to carry out grid-connected operation due to the lack of connection conditions of the on-site equipment. Moreover, the current grid-connected mode adjusts the phase and synchronization by adjusting the speed of the generator set, which has low control accuracy and is prone to cause excessive impact and equipment damage due to mismatch of phase, voltage and frequency. SUMMARY

[0005] In view of the above problems, the present application provides a generator set zero power transfer device and method, which realizes grid connection and off-grid of the generator set by connecting a set of cables through the cooperation of the control module, the energy storage power supply and the generator set, effectively solving the problem of power grid impact caused by mismatch of phase, voltage and frequency.

[0006] To achieve the above object, the present application adopts the following technical solutions: The first aspect of the present application provides a zero power outage transfer device for a generator set, comprising a control module and an energy storage power supply, an input end of the control module being connected with the energy storage power supply and the generator set respectively, and an output end of the control module being connected with a power distribution cabinet on the grid side. The control module comprises a main control unit, a line switching module, an electric energy conversion module, and a voltage and current acquisition module, the control module detecting the voltage, frequency and phase on the output side of the generator set and on the grid side, controlling the voltage and current output by the energy storage power supply according to the detected signals, and completing the load transfer between the generator set and the grid side under zero power outage by taking the energy storage power supply as a conversion medium.

[0007] As a further implementation manner, the power distribution cabinet on the grid side is connected with the control module through a grid incoming line switch.

[0008] As a further implementation manner, the power distribution cabinet on the grid side is connected with the load through a load switch.

[0009] As a further implementation manner, a plurality of load switches are provided, and the power distribution cabinet on the grid side is connected with different loads through the plurality of load switches respectively.

[0010] As a further implementation manner, the power distribution cabinet on the grid side is connected with the grid side through a grid incoming line switch.

[0011] As a further implementation manner, the load transfer between the generator set and the grid side under zero power outage is completed by taking the energy storage power supply as a conversion medium, specifically: When the grid side needs to be shut down for maintenance, the generator set is connected with the grid for power supply, the grid incoming line switch is disconnected, the control module detects the voltage, frequency and phase on the grid side, the energy storage power supply is synchronized with the grid side under the control of the control module, the output voltage is ensured to be consistent with that on the grid side to supply power to the load, at the same time, the generator set is started, the controller detects the voltage, frequency and phase on the output end of the generator set, and controls the output of the energy storage power supply to be consistent with the voltage on the output end of the generator set to complete the synchronization with the output of the generator set, then the generator set is put into operation, and the energy storage power supply is withdrawn from operation.

[0012] As a further implementation manner, the load transfer between the generator set and the grid side under zero power outage is completed by taking the energy storage power supply as a conversion medium, specifically: When the power grid side needs to resume power supply after maintenance, the control module cuts off the power supply circuit of the generator set, the energy storage power supply keeps consistent with the generator set through the voltage output by the control module, and supplies power to the load, then the energy storage power supply keeps consistent with the voltage of the power grid side under the control of the control module, after the synchronization of the energy storage power supply and the power grid side is completed, the power grid incoming line switch is closed, the energy storage power supply gradually exits the power supply, and the power grid completes the resumption of power supply.

[0013] In a second aspect, the application provides a zero-outage power supply switching method for a generator set, based on the zero-outage power supply switching device for a generator set in the first aspect, comprising the following steps: When the power grid side needs to be powered by the generator set for maintenance, the power grid incoming line switch is disconnected, the control module detects the voltage, frequency and phase of the power grid side, the energy storage power supply is synchronized with the power grid side under the control of the control module, the output voltage is kept consistent with the power grid side, and power is supplied to the load, at the same time, the generator set is started, the controller detects the voltage, frequency and phase of the output end of the generator set, controls the output of the energy storage power supply to be consistent with the voltage of the output end of the generator set, and completes the synchronization with the output of the generator set, then the generator set is put into operation, and the energy storage power supply exits the operation.

[0014] As a further implementation, it further comprises: When the power grid side needs to resume power supply after maintenance, the control module cuts off the power supply circuit of the generator set, the energy storage power supply keeps consistent with the generator set through the voltage output by the control module, and supplies power to the load, then the energy storage power supply keeps consistent with the voltage of the power grid side under the control of the control module, after the synchronization of the energy storage power supply and the power grid side is completed, the power grid incoming line switch is closed, the energy storage power supply gradually exits the power supply, and the power grid completes the resumption of power supply.

[0015] As a further implementation, the control module detects the voltage of the power grid side, when the voltage meets the set threshold, the energy storage power supply supplies power to the load under the control of the control module.

[0016] Compared with the prior art, the application has the following beneficial effects: The zero-outage power supply switching device for a generator set of the application has one end connected to a generator set and the other end connected to a standby interval of a power distribution cabinet on the power grid side. When the power grid side needs to be maintained, the energy storage power supply in the device rapidly supplies power to the load under the control of the control module without affecting sensitive loads when the power grid is powered off and the generator set has not been connected to the load. Through the cooperative action of the energy storage power supply, the control module and the generator set in the control device, the load end does not need to be powered off when the power grid side is maintained. A set of cables is connected to realize the connection of the generator set and the off-grid, the non-outage operation can be realized, the use occasions are more extensive, and the problem of power grid impact caused by the mismatch of phase, voltage and frequency is effectively solved. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which form a part of this specification, are included to provide a further understanding of the application, and are incorporated into and constitute a part of this specification. The embodiments of the application, and their

[0018] Figure 1 A topological structure diagram of a zero power transfer device for a generator set; Figure 2 A state diagram when the power grid is normally powered; Figure 3 A state diagram when the energy storage power supply is used to power when the diesel generator car is grid-connected; Figure 4 A power supply state diagram after the diesel generator car is grid-connected. DETAILED DESCRIPTION

[0019] The application will be further described below with reference to the drawings and embodiments.

[0020] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the application pertains.

[0021] In the case of no conflict, the embodiments in the application and the features in the embodiments can be combined with each other.

[0022] Embodiment one As shown in Figures 1-4 The present embodiment provides a zero power transfer device for a generator set, comprising a control module and an energy storage power supply, the control module comprising a main control unit, a line switching module, an electric energy conversion module and a voltage and current acquisition module. The input end of the control module is connected with the energy storage power supply and the generator set, respectively, wherein the generator set is directly connected to the line switching module of the control module, and the energy storage power supply is connected to the line switching module after passing through the electric energy conversion device. The output end of the control module is connected to the power distribution cabinet on the grid side; the control module detects the voltage, frequency and phase signals of the output side of the generator set, as well as the voltage, frequency and phase signals of the grid side, and controls the voltage and current output by the energy storage power supply according to the detected signals, so as to complete the load transfer between the generator set and the grid side under zero power outage by taking the energy storage power supply as a conversion medium.

[0023] The application discloses a generator set zero power-off transfer device, which comprises a control module and an energy storage power supply.

[0024] Specifically, the energy storage power supply is used for supplying power for the load rapidly under the condition that the power grid is powered off and the generator set has not been connected to the load, so that the sensitive load is not affected, and the load end does not need to be powered off during the maintenance of the power grid.

[0025] The control module is the core of the control device, and comprises a main control unit, a line switching module, an electric energy conversion module and a voltage and current acquisition module. The control module has two inputs, namely an energy storage power supply input and a diesel generator car input. The control module has one output connected to a power distribution cabinet on the power grid side. The control module acquires signals such as voltage, frequency and phase of the output side of the generator set. Meanwhile, the control module also acquires signals such as voltage, frequency and phase of the power grid side switch QF (power grid incoming line switch). When the power grid side needs to be maintained or the maintenance is completed and the switch needs to be closed to supply power for the load end, the control module sends a control instruction to complete the corresponding operation.

[0026] The application will be further described in combination with the drawings.

[0027] As shown in Figure 1 , Q1, Q2 and Q3 in the distribution box are load switches, QF is a power grid incoming line switch, and Q4 is a control device access switch. The control module has two connection terminals, which are connected to the generator set and the distribution box respectively. The two inputs of the control module are the energy storage power supply and the output end of the generator set respectively. The control module acquires signals such as voltage, frequency and phase of the output side of the generator car. Meanwhile, the control module also acquires signals such as voltage, frequency and phase of the power grid side switch QF.

[0028] When working normally, as shown in Figure 2 , Q1, Q2 and Q3 load switches are closed, QF power grid incoming line switch is closed, and Q4 control device access switch is opened, so that the power grid supplies power for the load.

[0029] As shown in Figure 3As shown, when grid-connected operation is required, first close Q4 switch, then open diesel generator, diesel generator starts and output port voltage reaches the set value, at the same time, the control module always detects the voltage, frequency and phase signals of the grid side, and the energy storage power supply always synchronizes with the grid side under the control of the control module, ensuring that the output voltage is consistent with the grid side. When the grid side switch QF is opened, the voltage and current acquisition module of the control module detects the voltage drop at the load end of the QF switch and transmits the signal to the main control unit. When the voltage drops to 90% of the rated voltage, the main control unit issues an instruction to control the energy storage power supply output power through the energy conversion unit to quickly supply power to the load, ensuring continuous power supply to the load side. At this time, the output voltage, frequency and phase are consistent with the grid side, and there is no impact load.

[0030] At the same time, the controller detects the voltage, frequency and phase of the generator output end, and controls the energy conversion unit through the main control unit to adjust the output of the energy storage power supply to be consistent with the voltage, frequency and phase of the diesel generator output, complete synchronization with the diesel generator output, and then the main control unit issues an instruction to control the line switching module to put the diesel generator into operation, and then issues an instruction to control the energy conversion device to exit the operation of the energy storage power supply, as shown. Figure 4 At this time, the diesel generator completes the grid-connected operation. The grid side can be normally operated for maintenance, repair, inspection and the like, and the load side is powered by the diesel generator, achieving uninterrupted operation.

[0031] When the grid side completes maintenance, repair and other operations and needs to restore power supply, first control the line switching unit to cut off the diesel generator power supply circuit through the main control unit of the control module, and at the same time, control the energy conversion device to restore the energy storage power supply to supply power to the load through the control module, ensuring uninterrupted power supply, as shown. Figure 3 Then adjust the voltage, frequency and phase of the energy storage power supply output through the control module to be consistent with the voltage, frequency and phase of the grid side, and complete synchronization, then close the grid side switch QF, and the energy storage power supply gradually exits the power supply, as shown. Figure 2 Finally, the grid completes the restoration of power supply.

[0032] Example Two The embodiment provides a zero power failure transfer method for a generator set, and a zero power failure transfer device for the generator set based on example one, and includes the following steps: When the power grid side needs to be shut down for maintenance, the generator set is connected to the power grid, the power grid incoming line switch is disconnected, the control module detects the voltage, frequency and phase of the power grid side, and the energy storage power supply completes synchronization with the power grid side under the control of the control module, ensuring that the output voltage is consistent with the power grid side to supply power to the load. At the same time, the generator set is started, the controller detects the voltage, frequency and phase of the output end of the generator set, and controls the output of the energy storage power supply to be consistent with the output voltage of the generator set to complete synchronization with the output of the generator set. Subsequently, the generator set is put into operation, and the energy storage power supply exits operation.

[0033] It also includes: When the power grid side is completed, the power supply needs to be restored, the control module is used to cut off the power supply circuit of the generator set, the energy storage power supply is used to output voltage consistent with the generator set, and the load is powered. Subsequently, under the control of the control module, the output of the energy storage power supply is consistent with the voltage of the power grid side, and after synchronization between the energy storage power supply and the power grid side is completed, the power grid incoming line switch is closed, the energy storage power supply gradually exits the power supply, and the power grid completes the restoration of the power supply.

[0034] Specifically, the diesel generator car (generator set) is connected to the power grid through the control equipment as follows: First, start the diesel generator car, and the control module collects the output side voltage of the generator car. When the voltage reaches the set threshold value, it meets the conditions for grid connection. The threshold value is generally 95% of the output voltage. Second, cut off the voltage of the power grid side. The control module collects the voltage of the load end of the QF switch on the power grid side. When the voltage drops to the set threshold value (generally 90% of the rated voltage), the control device controller sends a signal to connect the energy storage power supply to supply power to the load, ensuring that the load is continuously powered. At this time, the energy storage power supply outputs the same voltage, phase and frequency as the power grid through the control module to supply power to the load; Third, the control module detects the voltage, frequency and phase information of the output end of the generator set, and the energy storage power supply output starts to synchronize with the output of the generator set through the control module. After synchronization is completed, the generator set can supply power to the load, and the energy storage power supply exits the power supply; The diesel generator car is disconnected through the control equipment as follows: First, issue a disconnection instruction through the control module, disconnect the diesel generator car from the load, and at the same time the energy storage power supply supplies power to the load through the control module to ensure that the load is continuously powered. At this time, the voltage, frequency and phase of the output of the energy storage power supply through the control module are consistent with the output of the diesel generator car; Second, the energy storage power supply keeps the output voltage, frequency and phase consistent with the power grid side through the control module. After synchronization with the power grid side is completed, the power grid side switch can be closed; Third, turn off the generator set, and thus complete the disconnection operation of the generator set.

[0035] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0036] The above merely describes the preferred embodiments of the present application and is not intended to limit the present application. The present application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A zero-power-off power transfer device for a generator set, characterized in that: It includes a control module and an energy storage power supply, wherein the input end of the control module is connected to the energy storage power supply and the generator set respectively, and the output end thereof is connected to the power distribution cabinet on the grid side; The control module includes a main control unit, a line switching module, an electric energy conversion module, and a voltage and current acquisition module. The control module detects the voltage, frequency, and phase on the output side of the generator set and the grid side, controls the voltage and current output by the energy storage power supply according to the detected signals, and uses the energy storage power supply as a conversion medium to complete the load transfer between the generator set and the grid side under zero power outage.

2. A zero-power-off power transfer device for a generator set as claimed in claim 1, characterized in that: The grid-side power distribution cabinet is connected to the control module via a grid incoming line switch.

3. The zero-power-off power transfer device for a generator set according to claim 1, characterized in that: The grid-side power distribution cabinet is connected to the load via a load switch.

4. A zero-power-off power transfer device for a generator set as claimed in claim 3, characterized in that: There are multiple load switches, and the grid-side distribution cabinet is connected to different loads through the multiple load switches.

5. The zero-power-off power transfer device for a generator set according to claim 1, characterized in that: The grid-side power distribution cabinet is connected to the grid side via a grid incoming line switch.

6. The zero-power-off power transfer device for a generator set according to claim 1, characterized in that: Energy storage power is used as the conversion medium to complete the load transfer between the generator set and the grid side under zero power outage, specifically: When the grid side needs to be shut down for maintenance, the generator set is connected to the grid for power supply, the grid incoming line switch is disconnected, and the control module detects the voltage, frequency and phase on the grid side. The energy storage power supply completes synchronization with the grid side under the control of the control module to ensure that the output voltage is consistent with the grid side and supply power to the load. At the same time, the generator set is started, and the controller detects the voltage, frequency and phase at the output end of the generator set, and controls the output of the energy storage power supply to be consistent with the output voltage of the generator set, completing synchronization with the generator set output. Then the generator set is put into operation and the energy storage power supply is shut down.

7. The zero-power-off power transfer device for a generator set according to claim 1, characterized in that: Energy storage power is used as the conversion medium to complete the load transfer between the generator set and the grid side under zero power outage, specifically: When the grid side maintenance is completed and power supply needs to be restored, the power supply circuit of the generator set is cut off through the control module. The voltage output by the energy storage power supply through the control module is consistent with the generator set to supply power to the load. Then, under the control of the control module, the output of the energy storage power supply is consistent with the grid side voltage. After the synchronization of the energy storage power supply and the grid side is completed, the grid incoming line switch is closed, the energy storage power supply gradually withdraws from power supply, and the grid completes power supply restoration.

8. A method for transferring power to a generator set without power outage, characterized in that: A zero-power-off power transfer device for a generator set according to any one of claims 1 to 7 comprises the following steps: When the grid side needs to be shut down for maintenance, the generator set is connected to the grid for power supply, the grid incoming line switch is disconnected, and the control module detects the voltage, frequency and phase on the grid side. The energy storage power supply completes synchronization with the grid side under the control of the control module to ensure that the output voltage is consistent with the grid side and supply power to the load. At the same time, the generator set is started, and the controller detects the voltage, frequency and phase at the output end of the generator set, and controls the output of the energy storage power supply to be consistent with the output voltage of the generator set, completing synchronization with the generator set output. Then the generator set is put into operation and the energy storage power supply is shut down.

9. A method for transferring power to a generator set without power outage according to claim 8, characterized in that: It also includes: When the grid side maintenance is completed and power supply needs to be restored, the power supply circuit of the generator set is cut off through the control module. The voltage output by the energy storage power supply through the control module is consistent with the generator set to supply power to the load. Then, under the control of the control module, the output of the energy storage power supply is consistent with the grid side voltage. After the synchronization of the energy storage power supply and the grid side is completed, the grid incoming line switch is closed, the energy storage power supply gradually withdraws from power supply, and the grid completes power supply restoration.

10. A method for transferring power to a generator set without power outage according to claim 8, characterized in that: The control module detects the voltage on the grid side. When the voltage meets the set threshold, the energy storage power supply supplies power to the load under the control of the control module.

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