A multiple fan sequential start circuit

Abstract

The utility model discloses a kind of multiple fan sequential starting circuits, including first circuit and second circuit, first circuit and second circuit are in parallel, first circuit includes three-phase ac power supply, N fan groups and AC contactor normally open contact, one or more fans are included in each fan group, three-phase ac power supply is taken from diesel generating set, and there is an AC contactor normally open contact in series between each fan and three-phase ac power supply;Second circuit includes single-phase power supply, main control branch and N-1 sub-control branch, single-phase power supply is electrically connected with main control branch and sub-control branch respectively, single-phase power supply is taken from diesel generating set, main control branch includes passive switch, N-1 power-on delay relay coil and the AC contactor coil corresponding to the AC contactor normally open contact in series with fan in one of fan groups, and the power-on delay relay coil and AC contactor coil in parallel are connected with passive switch and single-phase power supply in series, each sub-control branch corresponds to control the opening of one of fan group in remaining fan group, and sub-control branch includes AC contactor coil and one power-on delay relay normally open contact, the power-on delay relay normally open contact in all sub-control branch and the power-on delay relay coil in main control branch one-to-one, the AC contactor coil in sub-control branch and the AC contactor normally open contact in series with fan in fan group controlled by this sub-control branch one-to-one, multiple AC contactor coils in same sub-control branch are connected in parallel, and the AC contactor coil in parallel is connected with the power-on delay relay normally open contact in this sub-control branch and single-phase power supply in series.The utility model can control multiple fan groups to start sequentially in turn, avoid diesel generating set to be loaded too much at same time, and improve power quality.

Description

Technical Field

[0001] This utility model belongs to the field of circuit control technology, and more specifically, it relates to a multi-fan sequential start-up circuit. Background Technology

[0002] The generator container is equipped with a diesel generator set. When the diesel generator set is working, the louvers on the generator container are opened to ensure airflow inside and outside the generator container. The coolant in the diesel engine cooling passage absorbs the heat generated and flows to the radiator. A cooling fan is installed on the radiator. The fan blades rotate to accelerate the airflow, which lowers the temperature of the radiator. After the engine coolant temperature is lowered, it flows towards the generator set.

[0003] When the generator set power increases, the volume and length of the cooling pipes increase accordingly due to the increase in the size of the engine itself, and the power and number of cooling fans on the radiator also increase at the same time.

[0004] After the unit starts running, multiple cooling fans start simultaneously, causing the unit to be under excessive load for a period of time, which reduces the generator's output voltage and affects power quality. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model innovatively provides a multi-fan sequential start-up circuit that controls multiple fan units to start sequentially, avoiding excessive load on diesel generator sets at the same time and improving power quality.

[0006] To achieve the aforementioned technical objectives, this utility model discloses a multi-fan sequential start-up circuit, comprising a first circuit and a second circuit, wherein the first circuit and the second circuit are connected in parallel.

[0007] The first circuit includes a three-phase AC power supply, N fan units, and normally open contacts of AC contactors, where N is a natural number greater than or equal to 2. Each fan unit includes one or more fans, the N fan units are connected in parallel, and multiple fans in each fan unit are connected in parallel. The three-phase AC power supply is taken from a diesel generator set. The number of normally open contacts of the AC contactors is the same as the total number of fans in the N fan units. Each fan is connected in series with the three-phase AC power supply via one normally open contact of the AC contactor.

[0008] The second circuit includes a single-phase power supply, a main control branch, and N-1 auxiliary control branches. The main control branch and the auxiliary control branches are connected in parallel. The single-phase power supply is electrically connected to both the main control branch and the auxiliary control branches. The single-phase power supply is taken from a diesel generator set.

[0009] The main control branch includes a passive switch, N-1 energized time-delay relay coils, and an AC contactor coil corresponding to the normally open contact of an AC contactor connected in series with one of the wind turbines in the wind turbine unit. The energized time-delay relay coils and the AC contactor coils are connected in parallel. The parallel-connected energized time-delay relay coils and AC contactor coils are connected in series with the passive switch and the single-phase power supply. The passive switch closes after the louvers on the generator container are opened or after the diesel generator set is running stably.

[0010] Each of the secondary control branches controls the activation of one of the remaining wind turbine units. Each secondary control branch controls one of the remaining wind turbine units. Each secondary control branch includes an AC contactor coil and a normally open contact of a time-delay relay. The normally open contacts of the time-delay relays in all the secondary control branches correspond one-to-one with the time-delay relay coils in the main control branch. The AC contactor coils in the secondary control branches correspond one-to-one with the normally open contacts of the AC contactors connected in series with the wind turbines in the wind turbine unit controlled by the secondary control branch. Multiple AC contactor coils in the same secondary control branch are connected in parallel. The parallel AC contactor coils are connected in series with the normally open contacts of the time-delay relays in the secondary control branch and the single-phase power supply.

[0011] Furthermore, it also includes thermal relays in the same number as the fans, wherein the coil of the thermal relay is connected in series with the normally open contact of the AC contactor and the fans, and the normally closed contact of the thermal relay is connected in series with the coil of the AC contactor.

[0012] Furthermore, the first circuit also includes miniature circuit breakers in the same number as the wind turbine units. Each miniature circuit breaker corresponds to one of the wind turbine units. The miniature circuit breaker is used to control the connection between each wind turbine unit and the three-phase AC power supply. The miniature circuit breaker is connected in series between the normally open contacts of the AC contactors connecting the three-phase AC power supply and the wind turbines in the wind turbine units.

[0013] Furthermore, the first circuit also includes a first main circuit breaker, which is connected in series between the three-phase AC power supply and the miniature circuit breaker.

[0014] Furthermore, the second circuit also includes a second main circuit breaker, which is connected in series between the single-phase power supply and the main control branch and the auxiliary control branch.

[0015] Furthermore, the passive switch is a rotary switch, which closes after the louvers on the power generation container are opened.

[0016] The passive switch is a relay, and the passive switch is electrically connected to the generator set controller. After the generator set controller detects that the voltage of the diesel generator set is stable, the generator set controller controls the passive switch to close.

[0017] The beneficial effects of this utility model are as follows:

[0018] This utility model's multi-fan sequential start circuit controls multiple fan units to start sequentially, avoiding excessive load on the diesel generator set at the same time and improving power quality. Attached Figure Description

[0019] Figure 1 This is a circuit diagram of the first circuit according to an embodiment of the present invention.

[0020] Figure 2 This is a circuit diagram of the second circuit in an embodiment of this utility model. Specific Implementation

[0021] The multi-fan sequential start-up circuit provided by this utility model will be explained and described in detail below with reference to the accompanying drawings.

[0022] This embodiment specifically discloses a multi-fan sequential start-up circuit, such as... Figure 1 and 2 As shown, it includes a first circuit and a second circuit, which are connected in parallel. The first circuit is a power generation circuit, and the second circuit is a control circuit.

[0023] like Figure 1 As shown, the first circuit includes a three-phase AC power supply, N fan units, and normally open contacts of AC contactors, where N is a natural number greater than or equal to 2. Each fan unit includes one or more fans, and the N fan units are connected in parallel. Multiple fans within each fan unit are connected in parallel. The number of fans in each fan unit can be the same or different. Fans can be grouped according to the number of fans or their power; this application does not limit the specific grouping rules. The three-phase AC power supply is taken from a diesel generator set. The number of normally open contacts of the AC contactors is the same as the total number of fans in the N fan units. Each fan is connected in series with a normally open contact of the AC contactor. In this application, one normally open contact of the AC contactor includes three normally open contacts, which are electrically connected to the U, V, and W phases of the three-phase AC power supply, respectively, to control the on / off switching of the three-phase AC power supply to the fans. The normally open contacts of the AC contactors connected to each fan unit close simultaneously, so that the three-phase AC power supply simultaneously supplies power to the fans in the same group, allowing the fans in the same group to work simultaneously.

[0024] The first circuit ensures the transmission and distribution of the three-phase AC power output from the diesel generator set, guaranteeing the power demand of the wind turbine.

[0025] like Figure 2As shown, the second circuit includes a single-phase power supply, a main control branch, and N-1 auxiliary control branches. The main control branch and auxiliary control branches are connected in parallel. The single-phase power supply is electrically connected to both the main control branch and the auxiliary control branch, and is drawn from a diesel generator set. The main control branch includes a passive switch, N-1 energized time-delay relay coils, and an AC contactor coil corresponding to the normally open contact of an AC contactor connected in series with one of the wind turbines in the wind turbine set. The energized time-delay relay coils and AC contactor coils are connected in parallel. The parallel energized time-delay relay coils and AC contactor coils are connected in series with the passive switch and the single-phase power supply. The passive switch is connected in series with the generator set. The louvers on the generator container open and close, or close after the diesel generator set is running stably. In actual operation, the louvers on the generator container open upon startup to allow for ventilation and heat dissipation, ensuring airflow. At this time, the passive switch can be controlled to close, meaning it closes when the diesel generator set starts. The passive switch can also close upon receiving a signal indicating stable operation of the diesel generator set (such as a voltage stability signal). This voltage stability signal can be output through the generator set controller. When the programmable output port of the generator set controller is closed, it outputs the diesel generator set voltage stability signal, and the passive switch closes. After the diesel generator set starts or runs stably, it supplies power to the second circuit. The specific timing of this power supply is set according to actual heat dissipation requirements.

[0026] Each secondary control branch controls the activation of one of the remaining wind turbine units. Each secondary control branch controls one of the remaining wind turbine units. Each secondary control branch includes an AC contactor coil and a normally open contact of a time-delay relay. The normally open contact of the time-delay relay in each secondary control branch corresponds to one of the time-delay relay coils in the main control branch. All normally open contacts of the time-delay relays in the secondary control branches correspond one-to-one with the time-delay relay coils in the main control branches. The number of AC contactor coils in a secondary control branch is determined by the number of wind turbines in the wind turbine unit it controls. Each AC contactor coil in a secondary control branch corresponds one-to-one with the normally open contact of the AC contactor connected in series with the wind turbine in the corresponding wind turbine unit. Multiple AC contactor coils in the same secondary control branch are connected in parallel. Each parallel AC contactor coil is connected in series with the normally open contact of the time-delay relay in that secondary control branch and a single-phase power supply. In this application, the delay time of the energizing delay relay is an increasing sequence, preferably an arithmetic progression, such as delay times of 5s, 10s, 15s, ..., meaning the wind turbines start sequentially at 5-second intervals. The time interval for starting the wind turbines is set according to specific needs.

[0027] After the diesel generator set starts or reaches stable operation, the passive switch closes, energizing the AC contactor coil and the time-delay relay coil in the main control branch. This closes the normally open contact of the AC contactor coil in the first circuit corresponding to the AC contactor coil in the main control branch, energizing the fans in the fan unit connected to that contactor, causing the fans in that group to start operating simultaneously. After the time-delay relay coil is energized, after the corresponding delay time, the normally open contact of the corresponding time-delay relay closes, energizing the AC contactor coil in the secondary control branch. This closes the normally open contact of the AC contactor coil in the first circuit corresponding to the contactor coil in that secondary control branch, causing the next fan unit to start. This process is repeated to ensure all fan units start sequentially according to the delay time sequence.

[0028] This application effectively avoids the problem of excessive load on the diesel generator set due to the simultaneous operation of all wind turbines, which affects power quality and effectively improves power quality.

[0029] Optionally, the passive switch is a rotary switch. The passive switch closes after the louvers on the generator container are opened. In this embodiment, the passive switch is manually controlled to close. When the diesel generator set is started, the rotary switch is turned to close it and supply power to the second circuit.

[0030] Optionally, the passive switch is a relay. The passive switch is electrically connected to the generator set controller. After the generator set controller detects that the voltage of the diesel generator set is stable, the generator set controller programmable output port closes and outputs a diesel generator set voltage stability signal. The passive switch receives the signal and closes. The generator set controller controls the passive switch to close.

[0031] In some embodiments, such as Figure 1 and 2 As shown, the multi-fan sequential start circuit of this application also includes thermal relays of the same number as the number of fans. The coils of the thermal relays are connected in series with the normally open contacts of the AC contactors and the fans, respectively, and the normally closed contacts of the thermal relays are connected in series with the coils of the AC contactors, respectively. The coils and normally closed contacts of the same thermal relay are respectively connected to the normally open contacts and coils of the same AC contactor, thereby controlling the same fan. The thermal relays are installed in the circuit at the front end of the fan to protect the fan from damage caused by overload, phase loss, three-phase current imbalance, and other faults. When the diesel generator set is overloaded, the winding current increases, the current in the thermal element of the thermal relay increases accordingly, the temperature of the bimetallic strip rises, and the degree of bending increases. When a certain value is reached, it pushes the internal mechanism to act, the normally closed contacts of the thermal relay open, and disconnects the fan from the three-phase AC power supply. In this embodiment, as shown... Figure 1As shown, the coil of the thermal relay is connected in series between the normally open contact of the AC contactor and the fan. When the fan is started, after the passive switch is closed, the normally closed contact of the thermal relay and the coil of the AC contactor are energized. After the normally open contact of the AC contactor is closed, the coil of the thermal relay is energized.

[0032] The appropriate model of AC contactor and thermal relay is selected based on the rated voltage, current and number of phases of a single fan.

[0033] In some embodiments, such as Figure 2 As shown, the first circuit also includes miniature circuit breakers (MCBs) in the same number as the wind turbine units. Each MCB corresponds to one wind turbine unit and controls the connection between each wind turbine unit and the three-phase AC power supply. The MCBs are connected in series between the three-phase AC power supply and the normally open contacts of the AC contactors connecting the wind turbines within the wind turbine units. This allows for individual control of each wind turbine unit's connection to the three-phase AC power supply, enabling more precise grouping of the wind turbines. Under normal conditions, the MCBs for each wind turbine unit are in the normally closed position. In the event of a wind turbine failure, the MCB is opened, and the wind turbine unit stops operating. The MCBs allow for individual control of each wind turbine unit. When a wind turbine in a particular unit fails, that unit is isolated from the others, allowing the other wind turbine units to continue operating normally, thus reducing the impact on heat dissipation efficiency.

[0034] The type of miniature circuit breaker is selected based on the sum of the power of the wind turbine unit, with appropriate pole number, current, and tripping characteristics. Since the wind turbine is an inductive load of motor type, a miniature circuit breaker with D-type tripping is selected.

[0035] Furthermore, such as Figure 1 As shown, the first circuit also includes a first main circuit breaker, which is connected in series between the three-phase AC power supply and the miniature circuit breaker to control the on / off state of the first circuit. When the diesel generator set is running stably, the first main circuit breaker closes and outputs power to provide a stable power supply to the wind turbine. Before the generator container is put into use, the first main circuit breaker is in the open state to ensure that the diesel generator set starts under no-load conditions.

[0036] In some alternative embodiments, such as Figure 2 As shown, the second circuit also includes a second main circuit breaker, which is connected in series between the single-phase power supply and the main control branch and the auxiliary control branch to control the on / off state of the second circuit.

[0037] The control logic of the multi-fan sequential start-up circuit of this application is illustrated below with a specific embodiment:

[0038] This embodiment uses a total of 13 fans, numbered 1D, 2D, 3D, 4D, 5D, 6D, 7D, 8D, 9D, 10D, 11D, 12D, and 13D. Fans 1D, 2D, and 3D form the first fan group, fans 4D, 5D, and 6D form the second fan group, fans 7D, 8D, and 9D form the third fan group, and fans 10D, 11D, 12D, and 13D form the fourth fan group.

[0039] The delay time of the power-on delay relay controlling the start of the second group of wind turbines is 5 seconds, the delay time of the power-on delay relay controlling the start of the third group of wind turbines is 10 seconds, and the delay time of the power-on delay relay controlling the start of the fourth group of wind turbines is 15 seconds. The delay time is calculated from the start of the first group of wind turbines.

[0040] When the diesel generator set starts, the second main circuit breaker 6QF closes, and the miniature circuit breakers 2QF, 3QF, 4QF, and 5QF corresponding to the first, second, and third wind turbine units close. The passive switch closes when the diesel generator set starts or when it receives a signal indicating stable operation. This energizes the coils of AC contactors 1KM, 2KM, and 3KM, as well as the coils of time-delay relays 1KT, 2KT, and 3KT. If a first main circuit breaker and a miniature circuit breaker are installed, when the diesel generator set is running stably, the first main circuit breaker 1QF closes, and the normally open contacts of AC contactors 1KM, 2KM, and 3KM close, energizing and starting the first set of wind turbines (fans 1D, 2D, and 3D). Five seconds after the fans 1D, 2D, and 3D start running, the normally open contact of time-delay relay 1KT closes, and the normally open contacts of AC contactors 4KM, 5KM, and 6KM close, energizing the second set of wind turbines. Fans 3D, 4D, and 5D were energized and started running. Ten seconds after fans 1D, 2D, and 3D started running, the normally open contact of the 2KT time-delay relay closed, and the normally open contacts of AC contactors 7KM, 8KM, and 9KM closed, energizing fans 7D, 8D, and 9D in the third fan group and starting running. Fifteen seconds after fans 1D, 2D, and 3D started running, the normally open contact of the 3KT time-delay relay closed, and the normally open contacts of AC contactors 10KM, 11KM, 12KM, and 13KM closed, energizing fans 10D, 11D, 12D, and 13D in the fourth fan group and starting running. At this point, all fans had successfully started running, completing the sequential startup of the four fan groups.

[0041] The coils of thermal relays FR1, FR2, and FR3 are connected in series in the circuit containing the normally open contacts of AC contactors 1KM, 2KM, and 3KM; the normally closed contacts of thermal relays FR1, FR2, and FR3 are connected in series in the circuit containing the coils of AC contactors 1KM, 2KM, and 3KM. The coils of thermal relays FR4, FR5, and FR6 are connected in series in the circuit containing the normally open contacts of AC contactors 4KM, 5KM, and 6KM; the normally closed contacts of thermal relays FR4, FR5, and FR6 are connected in series in the circuit containing the coils of AC contactors 4KM, 5KM, and 6KM. The coils of thermal relays FR7, FR8, and FR9 are connected in series in the circuit containing the normally open contacts of AC contactors 7KM, 8KM, and 9KM. The normally closed contacts of relays FR7, FR8, and FR9 are connected in series in the circuit containing the coils of AC contactors 7KM, 8KM, and 9KM; the coils of thermal relays FR10, FR11, FR12, and FR13 are connected in series in the circuit containing the normally open contacts of AC contactors 10KM, 11KM, 12KM, and 13KM; the normally closed contacts of thermal relays FR10, FR11, FR12, and FR13 are connected in series in the circuit containing the coils of AC contactors 10KM, 11KM, 12KM, and 13KM. When a thermal relay element operates, its normally closed contact opens, the coil of the AC contactor in its circuit is de-energized, and the normally open contact of the AC contactor changes from closed to open, stopping the corresponding fan and effectively protecting the fan.

[0042] This application effectively enables the sequential starting of multiple wind turbines, avoiding excessive load on the diesel generator set at the same time, which could affect the power quality.

[0043] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0044] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0045] In the description of this specification, the references to terms such as "this embodiment," "an embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any at least one embodiment or example. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0046] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0047] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and simple improvements made on the substantive content of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A multi-fan sequential start-up circuit, characterized in that, It includes a first circuit and a second circuit, which are connected in parallel. The first circuit includes a three-phase AC power supply, N fan units, and normally open contacts of AC contactors, where N is a natural number greater than or equal to 2. Each fan unit includes one or more fans, the N fan units are connected in parallel, and multiple fans in each fan unit are connected in parallel. The three-phase AC power supply is taken from a diesel generator set. The number of normally open contacts of the AC contactors is the same as the total number of fans in the N fan units. Each fan is connected in series with the three-phase AC power supply via one normally open contact of the AC contactor. The second circuit includes a single-phase power supply, a main control branch, and N-1 auxiliary control branches. The main control branch and the auxiliary control branches are connected in parallel. The single-phase power supply is electrically connected to both the main control branch and the auxiliary control branches. The single-phase power supply is taken from a diesel generator set. The main control branch includes a passive switch, N-1 energized time-delay relay coils, and an AC contactor coil corresponding to the normally open contact of an AC contactor connected in series with one of the wind turbines in the wind turbine unit. The energized time-delay relay coils and the AC contactor coils are connected in parallel. The parallel-connected energized time-delay relay coils and AC contactor coils are connected in series with the passive switch and the single-phase power supply. The passive switch closes after the louvers on the generator container are opened or after the diesel generator set is running stably. Each of the secondary control branches controls the activation of one of the remaining wind turbine units. Each secondary control branch controls one of the remaining wind turbine units. Each secondary control branch includes an AC contactor coil and a normally open contact of a time-delay relay. The normally open contacts of the time-delay relays in all the secondary control branches correspond one-to-one with the time-delay relay coils in the main control branch. The AC contactor coils in the secondary control branches correspond one-to-one with the normally open contacts of the AC contactors connected in series with the wind turbines in the wind turbine unit controlled by the secondary control branch. Multiple AC contactor coils in the same secondary control branch are connected in parallel. The parallel AC contactor coils are connected in series with the normally open contacts of the time-delay relays in the secondary control branch and the single-phase power supply.

2. The multi-fan sequential start-up circuit according to claim 1, characterized in that, It also includes thermal relays in the same number as the fans, wherein the coil of the thermal relay is connected in series with the normally open contact of the AC contactor and the fans, and the normally closed contact of the thermal relay is connected in series with the coil of the AC contactor.

3. The multi-fan sequential start-up circuit according to claim 1, characterized in that, The first circuit also includes miniature circuit breakers in the same number as the wind turbine units. Each miniature circuit breaker corresponds to one of the wind turbine units. The miniature circuit breaker is used to control the on / off connection of each wind turbine unit to the three-phase AC power supply. The miniature circuit breaker is connected in series between the three-phase AC power supply and the normally open contacts of the AC contactors connecting the wind turbines in the wind turbine units.

4. The multi-fan sequential start-up circuit according to claim 3, characterized in that, The first circuit also includes a first main circuit breaker, which is connected in series between the three-phase AC power supply and the miniature circuit breaker.

5. The multi-fan sequential start-up circuit according to claim 1, characterized in that, The second circuit also includes a second main circuit breaker, which is connected in series between the single-phase power supply and the main control branch and the auxiliary control branch.

6. The multi-fan sequential start-up circuit according to claim 1, characterized in that, The passive switch is a rotary switch, which closes when the louvers on the power generation container are opened.

7. The multi-fan sequential start-up circuit according to claim 1, characterized in that, The passive switch is a relay, and the passive switch is electrically connected to the generator set controller. After the generator set controller detects that the voltage of the diesel generator set is stable, the generator set controller controls the passive switch to close.

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