Diesel generating set multi-rotating-speed self-adaptive control strategy

Abstract

The invention discloses a multi-rotating-speed self-adaptive control strategy for a diesel generating set, relates to the technical field of diesel generating sets, and solves the technical problem of relatively high energy consumption caused by fixed rotating speed and manual rotating speed adjustment of an existing diesel generating set. The strategy comprises the steps that an electricity load current value is obtained, the working state of a relay set connected with a control circuit of a rotating speed controller is controlled according to the fact that the electricity load current value is located at a preset electricity load standard value, and therefore a rotating speed output mode, corresponding to the working state of the relay set, in the rotating speed controller is triggered. And the diesel engine operates at the preset rotating speed in the rotating speed output mode. Different rotating speeds of the diesel engine are controlled, electricity loads in different ranges automatically correspond to different rotating speeds of the diesel engine, the rotating speed of the diesel engine is increased when the electricity loads are large, the rotating speed of the diesel engine is reduced when the electricity loads are small, and the purpose of saving oil and energy is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of diesel generator sets, and more specifically, to a multi-speed adaptive control strategy for diesel generator sets. Background Art

[0002] Diesel generator sets, since the frequency of electrical equipment is generally fixed, such as 50Hz or 60Hz, commonly used diesel generator sets are generally based on constant speed. Diesel generator sets use a constant speed controller motherboard. The seventh and ninth terminals of the constant speed controller motherboard are connected to a manually adjustable resistor. The resistance value has been preset during debugging, that is, when there is no load output, it runs at idle speed. When there is load output, regardless of the load size, it must be adjusted to the rated working speed. When running at medium and low loads for a long time, the mechanical work loss at high speed must still be maintained. Moreover, the rated working speed of the diesel engine is generally not the lowest fuel consumption point, so the comprehensive energy consumption is relatively large.

[0003] The conventional constant speed control strategy of existing diesel generator sets generally has only one rated operating speed. The conventional constant speed control strategy of generator sets has the following problems:

[0004] 1. Since there is only one preset rated operating speed, regardless of the output load, it must be maintained at a high speed. The rated operating speed is not the lowest fuel consumption point of the diesel engine. At the same time, when running at low and medium loads for a long time, the mechanical work loss to maintain a high speed is large and the energy consumption is high.

[0005] 2. The rated operating speed of existing diesel generator sets is preset. If you want to change it to other operating speeds, you must adjust it manually, and the adjustment personnel must have a high level of skills. It is also impossible to automatically adjust it in real time according to the actual power load demand, resulting in a large overall energy consumption. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a multi-speed adaptive control strategy for a diesel generator set in view of the deficiencies in the prior art, so as to solve the technical problem that the existing diesel generator set has a fixed speed and the speed is manually adjusted, resulting in high energy consumption.

[0007] The present invention discloses a multi-speed adaptive control strategy for a diesel generator set, which strategy includes obtaining a power load current value, and controlling the working state of a relay group connected to a control circuit of a speed controller according to a comparison between the power load current value and a preset power load standard value, thereby triggering a speed output mode in the speed controller corresponding to the working state of the relay group, so that the diesel engine operates at a speed preset in the speed output mode.

[0008] As a further improvement, a relay group, M resistors and M standard values ​​of power load are set, the signal input end of the speed controller is electrically connected to the external power supply through M resistors connected in series, the relay group includes M relays, and the two ends of each resistor are connected to a normally open switch of a relay in a one-to-one correspondence, where M is a natural number greater than zero.

[0009] Furthermore, the speed output mode of the speed controller is determined according to the magnitude relationship between the power load standard value and the power load current value.

[0010] Furthermore, the method for determining the speed output mode of the speed controller is:

[0011] When M is equal to one, when the electric load current value is less than the first electric load standard value A1, the M relays are in an off state, and the external power supply is connected to the signal input end of the speed controller through M resistors, so that the speed controller controls the speed of the generator set to be in N1 mode; otherwise, the M relays are in an on state, and the external power supply inputs a signal to the signal input end of the speed controller, so that the speed controller controls the speed of the generator set to be in N2 mode;

[0012] When M is greater than one, when the electric load current value is less than the first electric load standard value A1, the M relays are all in a disconnected state, and the external power supply is connected to the signal input end of the speed controller through M resistors, so that the speed controller controls the speed of the generator set to be in N1 mode, otherwise, it is determined whether the electric load current value is less than the m+1th electric load current standard value;

[0013] When the electric load current value is less than the m+1th electric load current standard value, m of the relays are controlled to be turned on and the other relays are turned off, so that the speed controller controls the speed of the generator set to be in N(m+1) mode;

[0014] When m+1=M, the M relays are all in the on state, and the external power supply is connected to the signal input terminal of the speed controller, so that the speed controller controls the speed of the generator set to be in N(M+1) mode;

[0015] Here, m is a natural number greater than or equal to one and less than M.

[0016] Furthermore, the relay is an undercurrent relay.

[0017] Beneficial Effects

[0018] The advantages of the present invention are:

[0019] The present invention obtains the electric load current value, and controls the working state of a relay group connected to a control circuit of a speed controller according to the electric load current value being within a preset electric load standard value, thereby triggering a speed output mode in the speed controller corresponding to the working state of the relay group, so that the diesel engine runs at a speed preset in the speed output mode, and realizes control of different speeds of the diesel engine, and realizes that different ranges of electric loads automatically correspond to different diesel engine speeds. When the electric load is large, the speed of the diesel engine increases, and when the electric load is small, the speed of the diesel engine decreases, thereby achieving the purpose of saving fuel and energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a flow chart of the diesel generator speed control strategy of the present invention;

[0021] Figure 2 It is the on-site installation diagram of the generator set of the present invention;

[0022] Figure 3 It is the wiring diagram of the relay group and the speed controller of the present invention.

[0023] Among them, U1-speed controller, R1-first resistor, R2-second resistor, R3-third resistor, KA1-first relay, KA2-second relay, KA3-third relay, KA1-1-normally open switch of the first relay, KA2-1-normally open switch of the second relay, KA3-1-normally open switch of the third relay. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0025] See also Figure 1-Figure 3 The present invention provides a multi-speed adaptive control strategy for a diesel generator set, which includes obtaining a power load current value, and controlling the working state of a relay group connected to a control circuit of a speed controller U1 according to a comparison between the power load current value and a preset power load standard value, thereby triggering a speed output mode in the speed controller U1 corresponding to the working state of the relay group, so that the diesel engine operates at a preset speed in the speed output mode.

[0026] A relay group, M resistors and M power load standard values ​​are set, the signal input end of the speed controller is electrically connected to the external power supply through the M resistors connected in series, the relay group includes M relays, and the two ends of each resistor are connected to a normally open switch of a relay in a one-to-one correspondence, where M is a natural number greater than zero. The speed output mode of the speed controller is determined according to the magnitude relationship between the power load standard value and the power load current value.

[0027] The method for determining the speed output mode of the speed controller is:

[0028] When M is equal to one, when the electric load current value is less than the first electric load standard value A1, the M relays are in an off state, and the external power supply is connected to the signal input terminal of the speed controller through the M resistors, so that the speed controller controls the speed of the generator set to be in the N1 mode; otherwise, the M relays are in an on state, and the external power supply inputs a signal to the signal input terminal of the speed controller, so that the speed controller controls the speed of the generator set to be in the N2 mode;

[0029] When M is greater than one, when the electric load current value is less than the first electric load standard value A1, the M relays are all in the disconnected state, and the external power supply is connected to the signal input terminal of the speed controller through M resistors, so that the speed controller controls the speed of the generator set to be in the N1 mode, otherwise, it is determined whether the electric load current value is less than the m+1th electric load current standard value;

[0030] When the electric load current value is less than the standard value of the electric load current of the m+1th electric load, m relays are controlled to be turned on and other relays are turned off, so that the speed controller controls the speed of the generator set to be in the N(m+1) mode;

[0031] When m+1=M, all M relays are in the on state, and the external power supply is connected to the signal input terminal of the speed controller, so that the speed controller controls the speed of the generator set to be in N(M+1) mode;

[0032] Here, m is a natural number greater than or equal to one and less than M.

[0033] The relay is an undercurrent relay. A relay that operates when the current passing through the relay decreases to below its setting value is called an undercurrent relay. When the detected current is greater than the undercurrent setting value, the undercurrent output relay is energized, otherwise the output relay is released. The maximum withstand current of the relay monitoring current range must be greater than the maximum output current of the generator set.

[0034] When the load current flows through the relay group, the relays in the relay group only determine whether the threshold for automatic opening or closing is reached according to the load current, and the relays will not disconnect the load current.

[0035] At the same time, a frequency-stabilizing current power supply device is added to the output current end of the diesel generator set. When the diesel generator set emits currents of different frequencies within the multi-speed range that can be set, the current frequency can be stabilized to the allowable deviation range of the required frequency (50Hz or 60Hz) of the electrical load, so as to protect the electrical equipment and ensure that the frequency of the output load current always meets the frequency requirements of the electrical equipment, thereby protecting the electrical equipment.

[0036] like Figure 3 As shown, the present invention provides an embodiment:

[0037] Set three standard values ​​of power load, and set three relays connected in series in the relay group.

[0038] The three electric load standard values ​​include a first electric load standard value A1 , a second electric load current value A2 , and a third electric load current value A3 .

[0039] The three relays include a first relay KA1 , a second relay KA2 , and a third relay KA3 .

[0040] The external power supply is electrically connected to the signal input end of the speed controller U1 through a first resistor R1, a second resistor R2 and a third resistor R3 connected in series. The normally open switch KA1-1 of the first relay is connected in parallel with the first resistor R1, the normally open switch KA2-1 of the second relay is connected in parallel with the second resistor R2, and the normally open switch KA3-1 of the third relay is connected in parallel with the third resistor R3.

[0041] When the electrical load current value is less than the first electrical load standard value A1, the normally open switch KA1-1 of the first relay, the normally open switch KA2-1 of the second relay and the normally open switch KA3-1 of the third relay remain in the normally open state, and the external power supply is connected to the signal input end of the speed controller U1 through the first resistor R1, the second resistor R2 and the third resistor R3 connected in series, and the speed controller U1 controls the speed of the generator to be in N1 mode.

[0042] When the electrical load current value is less than the second electrical load standard value A2 and greater than or equal to the first electrical load standard value A1, the first relay KA1 is turned on, the normally open switch KA1-1 of the first relay is closed, the normally open switch KA2-1 of the second relay and the normally open switch KA3-1 of the third relay both remain in the normally open state, and the external power supply is connected to the signal input end of the speed controller U1 through the second resistor R2 and the third resistor R3, and the speed controller U1 controls the speed of the generator to be in N2 mode.

[0043] When the electrical load current value is greater than or equal to the second electrical load standard value A2 and less than the third electrical load standard value A3, the first relay KA1 and the second relay KA2 are both connected, the normally open switch KA1-1 of the first relay and the normally open switch KA2-1 of the second relay are closed, and the normally open switch KA3-1 of the third relay remains normally open. The external power supply is connected to the signal input end of the speed controller U1 through the third resistor R3, and the speed controller U1 controls the speed of the generator to be in N3 mode.

[0044] When the electrical load current value is greater than or equal to the third electrical load standard value A3, the first relay KA1, the second relay KA2 and the third relay KA3 are all connected, the normally open switch KA1-1 of the first relay, the normally open switch KA2-1 of the second relay and the normally open switch KA3-1 of the third relay are all closed, the external power supply is directly connected to the signal input terminal of the speed controller U1, and the speed controller U1 controls the speed of the generator to be in N4 mode.

[0045] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A multi-speed adaptive control strategy for a diesel generator set, characterized in that: The strategy includes obtaining the power load current value, and controlling the working state of a relay group connected to the control circuit of a speed controller based on a comparison between the power load current value and a preset power load standard value, thereby triggering a speed output mode in the speed controller corresponding to the working state of the relay group, so that the diesel engine runs at a speed preset in the speed output mode.

2. A diesel generator set multi-speed adaptive control strategy according to claim 1, characterized in that: A relay group, M resistors and M standard values ​​of electrical load are set, the signal input end of the speed controller is electrically connected to the external power supply through the M resistors connected in series, the relay group includes M relays, and the two ends of each resistor are connected to a normally open switch of a relay in a one-to-one correspondence, wherein M is a natural number greater than zero.

3. A diesel generator set multi-speed adaptive control strategy according to claim 2, characterized in that: The speed output mode of the speed controller is determined according to the magnitude relationship between the power load standard value and the power load current value.

4. A diesel generator set multi-speed adaptive control strategy according to claim 3, characterized in that: The method for determining the speed output mode of the speed controller is: When M is equal to one, when the electric load current value is less than the first electric load standard value A1, the M relays are in an off state, and the external power supply is connected to the signal input end of the speed controller through M resistors, so that the speed controller controls the speed of the generator set to be in N1 mode; otherwise, the M relays are in an on state, and the external power supply is directly connected to the signal input end of the speed controller, so that the speed controller controls the speed of the generator set to be in N2 mode; When M is greater than one, when the electric load current value is less than the first electric load standard value A1, the M relays are all in a disconnected state, and the external power supply is connected to the signal input end of the speed controller through M resistors, so that the speed controller controls the speed of the generator set to be in N1 mode, otherwise, it is determined whether the electric load current value is less than the m+1th electric load current standard value; When the electric load current value is less than the m+1th electric load current standard value, m of the relays are controlled to be turned on and the other relays are turned off, so that the speed controller controls the speed of the generator set to be in N(m+1) mode; When m+1=M, the M relays are all in the on state, and the external power supply is connected to the signal input terminal of the speed controller, so that the speed controller controls the speed of the generator set to be in N(M+1) mode; Here, m is a natural number greater than or equal to one and less than M.

5. A diesel generator set multi-speed adaptive control strategy according to claim 2, characterized in that: The relay is an undercurrent relay.

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