Power-saving circuit of AC contactor
Technical Field
The invention relates to the field of low-voltage electric appliances, in particular to a power-saving circuit of an alternating current contactor, which can enable a traditional alternating current contactor to save electric energy.
Background
An Alternating Current Contactor (Alternating Current Contactor) is a low-voltage electrical appliance with very wide application, and by 2012, the number of Alternating Current contactors in online operation in China is up to 10 hundred million, and is increased at a speed of 8000 ten thousand newly increased every year. The working principle is that the electromagnet drives the movable contact (dynamic contact) and the static contact (dynamic contact) to close or separate, so as to achieve the purpose of switching on or off the circuit, and the three-phase induction motor is suitable for starting or controlling three-phase induction motors and other electric equipment.
Fig. 1 is a schematic diagram illustrating the operation of a conventional ac contactor. The traditional alternating current contactor mainly comprises a movable iron core, a static iron core, an excitation coil, a reset spring, a movable break contact and a movable make contact. When the excitation coil is connected with the voltage of AC220V, AC110V or AC380V (hereinafter referred to as AC220V, AC110V or AC380V as AC voltage or excitation power supply), the movable iron core is closed with the static iron core under the action of the magnetic force generated by the excitation coil, the movable contact point linked with the movable iron core is also closed, and the external circuit is connected through the movable contact point; when the AC voltage on the excitation coil is disconnected, the movable iron core is demagnetized and is separated from the static iron core under the action of the return spring, the movable contact is reset and disconnected, and an external circuit is cut off accordingly. In the alternating current contactor, the 'contacts linked with the movable iron core' have four groups, wherein three groups are used for connecting or disconnecting the main contacts of 'three-phase electricity', and the other group is the 'auxiliary contacts' of 'dynamic disconnection' or 'dynamic connection', and is used for controlling the system.
In summary, the working process of the conventional ac contactor can be divided into three stages of "pull-in", "hold-in", and "reset":
1. attracting: and the excitation coil is connected with the AC voltage, and the movable iron core and the static iron core are attracted. At this stage, in order to overcome the inertia of the movable iron core and the elastic force of the return spring, the excitation power supply must provide larger power (hereinafter, this power is referred to as "attraction power"), the movable iron core and the static iron core can attract each other, and the larger the "attraction power" is, the more crisp and faster the attraction is;
2. holding: and the excitation coil loop is continuously connected with the AC voltage, and the movable iron core and the static iron core are continuously kept in a pull-in state. At this stage, the excitation power supply only needs to provide a small power (hereinafter, this power is referred to as "holding power"), and the moving iron core and the static iron core can be continuously attracted. If the excitation power supply provides overlarge holding power at this stage, electric energy is wasted, and the alternating current contactor is heated and heated up in an undesirable way;
3. resetting: and the excitation coil breaks AC voltage, and the movable iron core and the static iron core are separated in a reset way.
The ac contactors have different purposes and different structures, but their working principles are the same as those in fig. 1.
The conventional AC contactor has the following serious disadvantages because the same AC voltage is applied to both the attraction and attraction stages of the excitation coil loop:
1. unnecessary power consumption: as mentioned above, in the pull-in and pull-in stages, the same AC voltage is applied to both the coil loops of the conventional AC contactor, so that the pull-in power is too high, resulting in unnecessary power loss;
2. heat generation: the heating up is a nuisance caused by the electric energy loss, and even the excitation coil loop of the traditional AC contactor can be burnt when the heating up is serious;
aiming at the serious defects of the traditional alternating current contactor, technicians in the electronic and electric appliance industries research and design various 'power saving circuits', 'power savers' and 'energy-saving alternating current contactors' for improving the performance of the traditional alternating current contactor. The respective research results of the patent applicant are disclosed in the Chinese patent application No. 97216246.1 of "high-efficiency energy-saving AC contactor", the application No. 94202133.9 of "energy-saving AC contactor device", and the application No. 201010144412.4 of "an energy-saving AC contactor"; universities and institutions in Hangzhou, Changzhou, Zhuhai and other places also have an electricity saver for improving the performance of the traditional alternating current contactor.
The above-mentioned prior art does provide a useful search and a certain achievement for improving the performance of the conventional ac contactor, but the following drawbacks are common:
1. the structure is complex and difficult to implement;
2. too many electronic devices are used, and electronic circuits are too complex; the 'AC contactor electricity-saving device' controlled by the single chip microcomputer is easy to be interfered by the AC contactor itself or the electromagnetic interference of the electrical appliances such as the motor and the like to cause the error execution of the internal program and the 'flying jump' error control which can cause a large accident in some occasions!
3. The sale price of the product is too high, for example, the sale price of the QXJB type AC contactor electricity-saving device produced by a certain limited company in Zhuhai city of Guangdong province is as high as 1500 yuan/station! The selling price of the small AC contactor is more than twenty yuan, the selling price of the medium AC contactor is also only about hundred yuan, and the expensive 'QXJB type AC contactor electricity-saving appliance' can lead users to be few.
4. Because the electronic circuit is complicated and the used electronic devices are more, the electricity-saving control part of the AC contactor is difficult to integrate with the AC contactor, and the electricity-saving control part needs to be additionally provided with a box, thereby causing inconvenient installation and troublesome wiring for users.
5. Because electronic circuits are complex and many electronic devices are used, the power consumption (AC-DC conversion loss, IC power consumption, actuator power consumption, etc.) of the power saving control part of the AC contactor will increase, and some power consumption may even be as large as the holding power of a small contactor.
Due to the above drawbacks of the prior art, the following situations arise: "at present, our country has already had a certain market for electricity-saving ac contactor, but it is not yet popular enough, and the traditional ac contactor is dominant in the use of users at present. The main reason is that the price of the energy-saving contactor is expensive, and a user cannot accept the energy-saving contactor once, so that the policy strength is increased on the popularization of the energy-saving contactor in China and the wide application of the energy-saving contactor is promoted. (reference 1: Qian Jinchuan et al. overview of energy-saving technology of AC contactor, China electronic business conditions, No. 4 of 2011)
Aiming at the current situation of the prior art, the invention aims to include: the purpose of 'from essence to simple and can be released for a long time only by simple and practical' is adhered to, 'the electronic technology is applied, the traditional industry is improved', and the 'alternating current contactor with the power-saving circuit', which has the advantages that an electronic circuit is as simple as possible, used devices are as few as possible, the price is as low as possible, and the performance exceeds that of the 'from essence to simple' in the prior art, is designed.
Disclosure of Invention
A power-saving circuit of an alternating current contactor is a four-port network provided with four ports N1, N2, P1 and P2, wherein the ports N1 and N2 are two input ports of the power-saving circuit, and the ports P1 and P2 are two output ports of the power-saving circuit; the input port N1 is connected with the terminal S1 of the AC voltage and the terminal 11 of the 'dynamic break auxiliary contact K' of the traditional AC contactor; the output port P1 is connected with the 12 ends of the dynamic breaking auxiliary contact K and the A1 end of the excitation coil L of the traditional AC contactor; the input port N2 is connected to the terminal S2 of the AC voltage, and the output port P2 is connected to the terminal a2 of the "exciting coil L".
The terminals S1 and S2 of the AC voltage can be connected reciprocally.
The ends 11 and 12 of the 'dynamic breaking auxiliary contact K' can be connected mutually and easily.
The A1 end and the A2 end of the exciting coil L can also be connected reciprocally.
The circuit structure of the four-port power-saving circuit and the connection mode of the four-port power-saving circuit and the dynamic-breaking auxiliary contact K are as follows:
(a) the dynamic breaking auxiliary contact K, the bipolar transient voltage suppression diode TVS and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (b), the 11 end of the dynamic breaking auxiliary contact K, the positive electrode of the first unipolar transient voltage suppression diode TVS1, and one end of the first capacitor C1 are all connected to the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the anode of the second unipolar transient voltage suppression diode TVS2 and the other end of the first capacitor C1 are connected with the P1 end; the cathode of the first unipolar transient voltage suppression diode TVS1 is connected to the cathode of the second unipolar transient voltage suppression diode TVS 2; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (C), the 11 end of the dynamic breaking auxiliary contact K, the cathode of the third unipolar transient voltage suppression diode TVS3, and one end of the first capacitor C1 are all connected to the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the cathode of the fourth unipolar transient voltage suppression diode TVS4 and the other end of the first capacitor C1 are connected with the P1 end; the anode of the third unipolar transient voltage suppression diode TVS3 is connected to the anode of the fourth unipolar transient voltage suppression diode TVS 4; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (d), the dynamic breaking auxiliary contact K, a Gas Discharge Tube (GDT) and a first capacitor C1 are connected in parallel, and then one end of the first capacitor is connected with the N1 terminal, and the other end of the first capacitor is connected with the P1 terminal; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (e), after the dynamic breaking auxiliary contact K, the semiconductor discharge Tubes (TSS) and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (f), the dynamic-breaking auxiliary contact K, an electrostatic suppressor (Electro-static discharge) ESD and a first capacitor C1 are connected in parallel, and then one end of the first capacitor is connected with the end N1, and the other end of the first capacitor is connected with the end P1; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (g), after the dynamic breaking auxiliary contact K, the piezoresistor VDR and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the end N1, and the other end of the dynamic breaking auxiliary contact K, the piezoresistor VDR and the first capacitor C1 is connected with the end P1; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (h), the 11 end of the dynamic breaking auxiliary contact K, the negative electrode of the first voltage stabilizing diode DW1 and one end of the first capacitor C1 are all connected with the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the negative electrode of the second voltage stabilizing diode DW2 and the other end of the first capacitor C1 are connected with the P1 end; the anode of the first zener diode DW1 is connected to the anode of the second zener diode DW 2; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
Or (i), the end 11 of the dynamic breaking auxiliary contact K, the anode of the third voltage stabilizing diode DW3 and one end of the first capacitor C1 are all connected with the end N1; the 12 end of the dynamic breaking auxiliary contact K, the anode of the fourth voltage stabilizing diode DW4 and the other end of the first capacitor C1 are all connected with the P1 end; the cathode of the third zener diode DW3 is connected to the cathode of the fourth zener diode DW 4; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The invention can achieve the following beneficial effects:
1. the price is low: the invention relates to a refined-to-simple 'electricity-saving circuit' for improving the performance of a traditional alternating current contactor, which only comprises three electronic devices (or four electronic devices), and the total cost is less than 0.5 RMB. The conventional ac contactor can be improved to a "power saving type ac contactor" of excellent performance with a few turns, solving the problem disclosed in reference 1: "at present, our country has already had a certain market for electricity-saving ac contactor, but it is not yet popular enough, and the traditional ac contactor is dominant in the use of users at present. The main reason is that the electricity-saving contactor is expensive, the user can not accept the electricity-saving contactor in one-time investment, the policy strength is increased in the popularization of the energy-saving contactor in China, the wide application of the energy-saving contactor is promoted, and conditions are created for the large-area popularization of the electricity-saving alternating current contactor;
2. and (5) material beauty: the three electronic devices (or four electronic devices) are all small in size, and can be integrated into the interior of a traditional alternating current contactor to manufacture an integrated power-saving alternating current contactor with a pleasant appearance. This is a problem that the prior art is not easy to realize;
3. reliable: the reliability of an electronic product is inversely proportional to the number of electronic devices used, and the price is proportional to the number of electronic devices used. The more electronic components used, the more complex the electronic circuitry, meaning the lower the reliability and the higher the price. The invention only uses three electronic devices (or four electronic devices) and all are power devices which are used for strong electricity and are not afraid of electromagnetic interference, therefore, the cost is low and the reliability is extremely high;
4. the AC voltage has wide action range, and when the AC voltage is reduced to 176V, the AC voltage can still be reliably attracted and held when the excitation power supply is AC 220V;
5. power saving: the actual measurement result also shows that the invention has higher electricity-saving efficiency.
In order to actually measure the electricity-saving efficiency of the invention, a prototype (only a plurality of electronic devices are needed, the prototype can be easily made), and the indexes of the following two alternating current contactors are respectively measured by using an EPM8200 multifunctional electrical parameter measuring instrument:
(1) CJX 2-1201 type conventional AC contactor (hereinafter referred to as conventional element) without the "power saving circuit" of the present invention;
(2) according to the method, the CJX 2-1201 type traditional alternating current contactor is improved after an electricity-saving circuit is additionally arranged, and the novel alternating current contactor (hereinafter referred to as an invention part) with the electricity-saving circuit is formed.
The results are as follows:
the above actual measurement results show that: the 'active power saving rate' of the invention reaches 65%, and the 'apparent power saving rate' reaches 76%.
Drawings
Fig. 1 is a schematic diagram of a conventional ac contactor;
FIG. 2 is a schematic circuit diagram of embodiment a;
FIG. 3 is a schematic circuit diagram of embodiment b;
FIG. 4 is a schematic circuit diagram of embodiment c;
FIG. 5 is a schematic circuit diagram of embodiment d:
FIG. 6 is a schematic circuit diagram of embodiment e:
FIG. 7 is a schematic circuit diagram of embodiment f:
FIG. 8 is a schematic circuit diagram of embodiment g:
FIG. 9 is a schematic circuit diagram of embodiment h:
FIG. 10 is a schematic circuit diagram of embodiment i:
FIG. 11 is a diagram of the operation of embodiment a:
FIG. 12 shows example a at t = t1An equivalent circuit diagram of time;
FIG. 13 shows example a at t = t2An equivalent circuit diagram of time;
FIG. 14 shows example a at t = t3An equivalent circuit diagram of time;
FIG. 15 shows example a at t = t4An equivalent circuit diagram of time;
FIG. 16 shows example a at t = t6An equivalent circuit diagram of time;
FIG. 17 shows example a at t = t7An equivalent circuit diagram of time;
FIG. 18 shows example a at t = t8An equivalent circuit diagram of time;
FIG. 19 shows example a at t = t10Equivalent circuit diagram of time.
Detailed Description
Embodiments of the present invention will be described below with reference to the drawings.
Fig. 2 is a schematic circuit diagram of an embodiment a of the present invention. In fig. 2: l is an excitation coil in the traditional alternating current contactor, and A1 and A2 are two connection ends of the excitation coil; k is the "" dynamic break auxiliary contact "" of the conventional AC contactor, 11, 12 are two connection terminals thereof; the dashed box 100 represents the power saving circuit of the present invention, which is a four-port network having two input terminals, i.e., terminals N1 and N2, and two output terminals, i.e., terminals P1 and P2; the input ports N1 and N2 are connected to the ends S1 and S2 of the AC voltage, respectively, and the output ports P1 and P2 are connected to the ends a1 and a2 of the exciting coil L, respectively;
the terminals S1 and S2 of the AC voltage can be connected reciprocally.
The ends 11 and 12 of the 'dynamic breaking auxiliary contact K' can be connected mutually and easily.
The A1 end and the A2 end of the exciting coil L can also be connected reciprocally.
The four-port power saving circuit 100 is composed of a bipolar transient voltage suppression diode TVS, a first capacitor C1 and a second capacitor C2, and the circuit structure and the connection mode of the four-port power saving circuit and the dynamic-breaking auxiliary contact K are as follows: after the dynamic breaking auxiliary contact K, the bipolar transient voltage suppression diode TVS and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; said P2 end being connected to said N2 end;
the power-saving circuit 100 is combined with the traditional alternating current contactor according to the mode, and a novel alternating current contactor with the power-saving circuit can be formed.
With reference to fig. 2 and 11: the mathematical expression of the AC voltage input from the terminals S1, S2 is:
u=UmSin(2πft+φ)
in the above formula: u is the instantaneous value of the AC voltage, UmIs the amplitude value of the AC voltage, f is the frequency of the AC voltage, and phi is the initial phase angle of the AC voltage.
For simplicity of explanation, it is assumed that the initial phase angle Φ =0, the instantaneous value u of the AC voltage is expressed as:
u=UmSin2πft
the waveform is shown in fig. 11. In the figure: t represents time and u represents the instantaneous value of the AC voltage.
The working principle of the bipolar transient voltage suppression diode TVS is as follows: when the voltage U is applied across itTBelow its breakdown voltage VBRWhen the transient voltage suppressor diode TVS is an insulator, the bipolar transient voltage suppressor diode TVS exhibits high impedance and is approximately open-circuited, that is, the bipolar transient voltage suppressor diode TVS is in a cut-off state; when the voltage U is applied across itTGreater than its breakdown voltage VBRWhen the diode is in use, avalanche is generated to present low impedance, which is approximate to short circuit, that is, the bipolar transient voltage suppression diode TVS is in conduction state. The working principle is as follows: the bipolar transient voltage suppression diode TVS can clamp the voltage at two ends thereof into breakdown voltage VBR。
The working process of the embodiment a is explained in the following with reference to the accompanying drawings:
with reference to fig. 2 and 11: t = t1When the AC voltage is on, the dynamic-breaking auxiliary contact K is in a closed short-circuit state, and the voltage U at the two ends of the first capacitor C1T0, is an approximate short circuit condition. The input AC voltage is directly applied to both ends of the exciting coil L through the dynamic breaking auxiliary contact K.
t=t1Instantaneous value of AC voltage:
u1=UmSin2πft1<USL
in the above formula, USLThe minimum pull-in voltage of the AC contactor is obtained. Due to u1<USLTherefore, the AC contactor with the power-saving circuit is not attracted, the dynamic-breaking auxiliary contact K is continuously kept in a closed short circuit state, and the u1The second capacitor C2 and the excitation coil L are charged through the dynamic-breaking auxiliary contact K, and fig. 12 is an equivalent circuit thereof, in which: i.e. ik1Denotes t = t1The current flowing through the dynamic break auxiliary contact K; i.e. ic21Denotes t = t1The charging current on the second capacitor C2; i.e. iL1Denotes t = t1The charging current on the field coil L.
t=t2Instantaneous value of AC voltage:
u2=UmSin2πft2>USL
due to u2>USLTherefore, the AC contactor with the power-saving circuit is attracted and enters an attraction state; the dynamic breaking auxiliary contact K enters a broken open circuit state; the first capacitor C1 begins to charge, u2The "holding" power is supplied to the exciter coil L via a first capacitor C1. Fig. 13 is an equivalent circuit thereof, in which: i.e. ic12Denotes t = t2The charging current on the first capacitor C1; i.e. ic22Denotes t = t2The charging current on the second capacitor C2; i.e. iL2Denotes t = t2The field current on the field coil L.
As the charging progresses, the voltage U across the first capacitor C1TContinuously increasing until t = t3At an instantaneous value of the AC voltage of u3=UmSin2πft3At this time, the voltage U across the first capacitor C1TThe value of the voltage has risen to the breakdown voltage V of the bipolar transient voltage suppression diode TVSBRThe said TVS is breakdown and conductive, and the voltage U at both ends is conductiveTIs clamped to its breakdown voltage VBRThe first capacitor C1 stops charging, and the AC voltage is changed to be in a conducting state by the bipolar transient voltage suppression diode TVSAnd then provides the "holding" power for the exciting coil L. Fig. 14 is an equivalent circuit thereof, in which: i.e. iTVS3Denotes t = t3When the voltage is higher than the threshold voltage, the bipolar transient voltage inhibits the conduction current of the diode TVS; i.e. ic23Denotes t = t3The charging current on the second capacitor C2; i.e. iL3Denotes t = t3The field current on the field coil L.
t=t4At an instantaneous value of the AC voltage of u4=UmSin2πft4At this time, the voltage U between the output terminal P1 and the terminal P2 of the power saving circuit 100CThe voltage U at the two ends of the bipolar transient voltage suppression diode TVS after rising to a higher valueT=u4-UC<VBRThe bipolar transient voltage suppression diode TVS is turned off. At the same time, as the AC voltage drops, the voltage U across the first capacitor C1TThe sum of the voltage UC on the second capacitor C2 is greater than u4The value of (a) is:
UC+UT>u4
therefore, the second capacitor C2 discharges to the exciting coil L as well as to the S1 terminal and the S2 terminal through the first capacitor C1. Fig. 15 is an equivalent circuit thereof, in which: i.e. ic2LDenotes t = t4When the bipolar transient voltage suppression diode TVS is turned off, the second capacitor C2 discharges to the excitation coil L; i.e. ic24Denotes t = t4The total discharge current of the second capacitor C2; i.e. iL4Denotes t = t4A follow current on the time-excitation coil L; i.e. ic14Denotes t = t4The discharge current of the first capacitor C1; i.e. ic4Denotes t = t4The first capacitor C1 and the second capacitor C2 discharge current to the terminals S1 and S2.
With reference to fig. 2 and 11: t = t6When the AC voltage has entered the negative half cycle with positive S2 and negative S1, t = t6At an instantaneous value of the AC voltage of u6=UmSin2πft6At this time, the charged electricity of the first capacitor C1 and the second capacitor C2 is completely discharged at the positive half cycle of the AC voltage, and t = t6From time u6The first capacitor C1, the second capacitor C2 and the exciting coil L are charged. Fig. 16 is an equivalent circuit thereof, in which: i.e. ic26Denotes t = t6The charging current of the second capacitor C2; i.e. iL6Denotes t = t6The charging current on the time-exciting coil L; i.e. ic16Denotes t = t6The charging current of the first capacitor C1.
As the charging progresses, the voltage U across the first capacitor C1TContinuously increasing until t = t7At an instantaneous value of the AC voltage of u7=UmSin2πft7At this time, the voltage U across the first capacitor C1THas risen to the breakdown voltage V of said bipolar TVSBRValue of (1) (its polarity is t = t)3Time VBRConversely), the bipolar TVS is turned on again, and the voltage U across the TVS is turned onTIs clamped again to breakdown voltage VBRThe first capacitor C1 stops charging, and the AC voltage is changed to a conducting bipolar TVS to continue to provide "holding" power to the field coil L. Fig. 17 is an equivalent circuit thereof, in which: i.e. iTVS7Denotes t = t7When the voltage is higher than the threshold voltage, the bipolar transient voltage inhibits the conduction current of the diode TVS; i.e. ic27Denotes t = t7The charging current on the second capacitor C2; i.e. iL7Denotes t = t7The field current on the field coil L.
t=t8At an instantaneous value of the AC voltage of u8=UmSin2πft8At this time, the voltage U between the output terminal P2 and the terminal P1 of the power saving circuit 100CHas risen to a higher value (polarity and t = t)4Time-reversal), the voltage U across the bipolar TVST=u8-UC<VBRThe bipolar transient voltage suppression diode TVS is turned off. At the same time, the voltage U across the first capacitor C1TAnd the voltage U on the second capacitor C2CThe sum is already greater than u8The value of (a) is:
UC+UT>u8
therefore, the second capacitor C2 discharges to the exciting coil L as well as to the S2 terminal and the S1 terminal through the first capacitor C1. Fig. 18 is an equivalent circuit thereof, in which: i.e. ic2LDenotes t = t8Then, after the bipolar transient voltage suppression diode TVS is turned off, the current (polarity and t = t) discharged from the second capacitor C2 to the exciting coil L4When reversed); i.e. ic28Denotes t = t8The total discharge current of the second capacitor C2; i.e. iL8Denotes t = t8A follow current on the time-excitation coil L; i.e. ic18Denotes t = t8The discharge current of the first capacitor C1; i.e. ic8Denotes t = t8The first capacitor C1 and the second capacitor C2 discharge current to the terminals S2 and S1.
And t = t6Time phases correspond, t = t10When the AC voltage has again entered the positive half cycle with positive S1 and negative S2, t = t10At an instantaneous value of the AC voltage of u10=UmSin2πft10At this time, the charged electricity of the first capacitor C1 and the second capacitor C2 is completely discharged at the negative half cycle of the AC voltage, and t = t10From time u10The first capacitor C1, the second capacitor C2 and the exciting coil L are charged. Fig. 19 is an equivalent circuit thereof, in which: i.e. iC210Denotes t = t10The charging current of the second capacitor C2; i.e. iL10Denotes t = t10The charging current on the time-exciting coil L; i.e. iC110Denotes t = t10The charging current of the first capacitor C1.
By circulating the above steps, the present embodiment completes the working processes of "pull-in" and "pull-in" of the ac contactor provided with the power saving circuit.
From the above, it can be seen that: the dynamic-breaking auxiliary contact K is matched with the first capacitor C1, so that the AC contactor with the electricity-saving circuit completes the work process of 'pull-in'; the bipolar transient voltage suppression diode TVS, the first capacitor C1 and the second capacitor C2 are matched with each other to provide 'holding' power for the alternating current contactor with the power-saving circuit.
FIG. 3 is a schematic circuit diagram of an embodiment b, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network having four ports N1, N2, P1, and P2, the connection method of the power saving circuit and each external port is the same as that in embodiment a, the power saving circuit is composed of a first unipolar transient voltage suppression diode TVS1, a second unipolar transient voltage suppression diode TVS2, a first capacitor C1, and a second capacitor C2, and the circuit structure and the connection method of the power saving circuit and the power-off auxiliary contact K in the conventional ac contactor are as follows: the 11 end of the dynamic breaking auxiliary contact K, the anode of the first unipolar transient voltage suppression diode TVS1 and one end of the first capacitor C1 are all connected with the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the anode of the second unipolar transient voltage suppression diode TVS2 and the other end of the first capacitor C1 are connected with the P1 end; the cathode of the first unipolar transient voltage suppression diode TVS1 is connected to the cathode of the second unipolar transient voltage suppression diode TVS 2; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: the present embodiment replaces the bipolar TVS of the embodiment a with the first unipolar TVS1 and the second unipolar TVS 2.
The working process of this example is the same as example a.
FIG. 4 is a schematic circuit diagram of an embodiment c, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network having four ports N1, N2, P1, and P2, the connection method of the power saving circuit and each external port is the same as that in embodiment a, the power saving circuit is composed of a third unipolar transient voltage suppression diode TVS3, a fourth unipolar transient voltage suppression diode TVS4, a first capacitor C1, and a second capacitor C2, and the circuit structure and the connection method of the power saving circuit and the power-off auxiliary contact K in the conventional ac contactor are as follows: the 11 end of the dynamic breaking auxiliary contact K, the cathode of the third unipolar transient voltage suppression diode TVS3 and one end of the first capacitor C1 are connected with the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the cathode of the fourth unipolar transient voltage suppression diode TVS4 and the other end of the first capacitor C1 are connected with the P1 end; the anode of the third unipolar transient voltage suppression diode TVS3 is connected to the anode of the fourth unipolar transient voltage suppression diode TVS 4; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: the present embodiment replaces the bipolar TVS of the embodiment a with the third unipolar TVS3 and the fourth unipolar TVS 4.
The working process of this example is the same as example a.
FIG. 5 is a schematic circuit diagram of an embodiment d, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network with four ports N1, N2, P1 and P2, the connection method with the external ports is the same as that of embodiment a, the power saving circuit is composed of a gas discharge tube GDT, a first capacitor C1 and a second capacitor C2, the circuit structure and the connection mode with a dynamic break auxiliary contact K in the traditional ac contactor are as follows: after the dynamic breaking auxiliary contact K, the gas discharge tube GDT and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: this embodiment replaces the bipolar transient voltage suppression diode TVS of embodiment a with a gas discharge tube GDT.
The working process of this example is the same as example a.
FIG. 6 is a schematic circuit diagram of an embodiment e, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network with four ports N1, N2, P1 and P2, the connection method with the external ports is the same as that of the embodiment a, the power saving circuit is composed of a semiconductor discharge tube TSS, a first capacitor C1 and a second capacitor C2, the circuit structure and the connection mode with a dynamic-breaking auxiliary contact K in the traditional ac contactor are as follows: after the dynamic breaking auxiliary contact K, the semiconductor discharge tube TSS and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: this embodiment replaces the bipolar transient voltage suppression diode TVS of embodiment a with a semiconductor discharge tube TSS.
The working process of this example is the same as example a.
FIG. 7 is a schematic circuit diagram of an embodiment f, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network with four ports of N1, N2, P1 and P2, the connection method with the external ports is the same as that of the embodiment a, the power saving circuit is composed of an electrostatic suppressor ESD, a first capacitor C1 and a second capacitor C2, the circuit structure and the connection mode with a dynamic-breaking auxiliary contact K in the traditional ac contactor are as follows: after the dynamic breaking auxiliary contact K, the electrostatic suppressor ESD and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: this embodiment replaces the bipolar transient voltage suppression diode TVS of embodiment a with an electrostatic suppressor ESD.
The working process of this example is the same as example a.
FIG. 8 is a schematic circuit diagram of an embodiment g, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network with four ports N1, N2, P1 and P2, the connection method with the external ports is the same as that in the embodiment a, the power saving circuit is composed of a piezoresistor VDR, a first capacitor C1 and a second capacitor C2, and the circuit structure and the connection method with the dynamic-breaking auxiliary contact K in the traditional ac contactor are as follows: after the dynamic breaking auxiliary contact K, the piezoresistor VDR and the first capacitor C1 are connected in parallel, one end of the dynamic breaking auxiliary contact K is connected with the N1 end, and the other end of the dynamic breaking auxiliary contact K is connected with the P1 end; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: the present embodiment replaces the bipolar transient voltage suppression diode TVS of embodiment a with a voltage dependent resistor VDR.
The working process of this example is the same as example a.
FIG. 9 is a schematic circuit diagram of an embodiment h, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network provided with four ports N1, N2, P1 and P2, the connection method of the power saving circuit and each external port is the same as that in embodiment a, the power saving circuit is composed of a first voltage stabilizing diode DW1, a second voltage stabilizing diode DW2, a first capacitor C1 and a second capacitor C2, and the circuit structure and the connection mode of the power saving circuit and an auxiliary dynamic-breaking contact K in a traditional alternating current contactor are as follows: the 11 end of the dynamic breaking auxiliary contact K, the negative electrode of the first voltage stabilizing diode DW1 and one end of the first capacitor C1 are all connected with the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the negative electrode of the second voltage stabilizing diode DW2 and the other end of the first capacitor C1 are connected with the P1 end; the anode of the first zener diode DW1 is connected to the anode of the second zener diode DW 2; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: the present embodiment replaces the bipolar transient voltage suppressing diode TVS of embodiment a with the first voltage stabilizing diode DW1 and the second voltage stabilizing diode DW 2.
The working process of this example is the same as example a.
FIG. 10 is a schematic circuit diagram of an embodiment i, which is composed of a power saving circuit 100 and a conventional AC contactor; the power saving circuit 100 is a four-port network provided with four ports N1, N2, P1 and P2, the connection method of the power saving circuit and each external port is the same as that in embodiment a, the power saving circuit is composed of a third voltage stabilizing diode DW3, a fourth voltage stabilizing diode DW4, a first capacitor C1 and a second capacitor C2, and the circuit structure and the connection mode of the power saving circuit and an auxiliary dynamic-breaking contact K in a traditional alternating current contactor are as follows: the 11 end of the dynamic breaking auxiliary contact K, the anode of the third voltage stabilizing diode DW3 and one end of the first capacitor C1 are all connected with the N1 end; the 12 end of the dynamic breaking auxiliary contact K, the anode of the fourth voltage stabilizing diode DW4 and the other end of the first capacitor C1 are all connected with the P1 end; the cathode of the third zener diode DW3 is connected to the cathode of the fourth zener diode DW 4; one end of a second capacitor C2 is connected with the P1 terminal, and the other end is connected with the P2 terminal; the P2 end is connected to the N2 end.
The circuit structure of this embodiment is basically the same as that of embodiment a, except that: the present embodiment replaces the bipolar transient voltage suppressing diode TVS of embodiment a with a third voltage stabilizing diode DW3 and a fourth voltage stabilizing diode DW 4.
The working process of this example is the same as example a.
The technical solutions of the present invention are disclosed above, and explained by the above embodiments. Those skilled in the art will understand that: the above embodiments are illustrative only, and not intended to limit the invention to the scope of the above embodiments, and all variations, modifications, and alternatives falling within the spirit and scope of the invention as defined by the appended claims are intended to be embraced by the present invention.