JP6974395B2 - Relay controller - Google Patents

Description

The present invention relates to a relay control device.

Patent Document 1 discloses a method of controlling a relay contact so that the timing at which the relay contact actually opens does not exceed the zero cross timing of the commercial power supply voltage.

Japanese Unexamined Patent Publication No. 11-273491 (published on October 8, 1999)

In the method described in Patent Document 1, since the relay contact opens before the zero cross timing of the commercial power supply voltage, the timing at which the arc discharge occurs is before the zero cross timing. When the relay contact is opened before the zero cross timing and at the timing when the arc discharge occurs, this cannot be detected by the relay contact signal, and there is a problem that the relay contact is deteriorated by the arc discharge.

The relay control device according to the present invention includes a zero-cross signal generation unit that generates a signal corresponding to the zero-cross of the AC power supply voltage, a relay contact signal generation unit that generates a relay contact signal indicating an electrical state between the relay contacts, and a relay contact signal generation unit. A relay control device including a control unit that generates a relay control signal, wherein the control unit uses information obtained from the relay contact signal when the relay contact was previously opened to achieve zero cross timing of the AC power supply voltage. A relay control signal is generated so that the relay contact opens at a desired delay timing.

According to the above configuration, since the relay contact opens after the zero cross timing of the AC power supply voltage, the timing at which the arc discharge occurs is after the zero cross timing. If the relay contact is opened after the zero cross timing and at the timing when the arc discharge occurs, this can be detected by the relay contact signal, and the desired delay can be obtained by feeding back to the subsequent relay control signal. The relay contact can be opened at the timing. As a result, the relay contacts can be repeatedly opened without causing an arc discharge, so that deterioration of the relay contacts can be suppressed.

In the relay control device according to the present invention, the relay contact signal may be maintained at the same level regardless of the value of the AC power supply voltage while the relay contact is closed.

According to the configuration, the relay contact signal can easily and accurately detect the electrical state between the relay contacts.

In the relay control device according to the present invention, the control unit uses the information obtained from the relay contact signal when the relay contact was previously closed at a desired advance timing with respect to the zero cross timing of the AC power supply voltage. It may be configured to generate a relay control signal such that the relay contact is closed.

According to the above configuration, the bounce period when the relay contact is closed is a period in which the AC power supply voltage approaches zero, and the arc discharge due to the bounce of the relay contact can be suppressed.

In the relay control device according to the present invention, when the relay contact is closed and opened, the polarity of the AC power supply voltage may be different depending on the timing at which the relay contact is closed and the timing at which the relay contact is opened next.

According to the above configuration, it is possible to suppress deformation (generation of unevenness) of the relay contact and avoid a problem that the relay contact is in a locked state.

In the relay control device according to the present invention, when the relay contacts are repeatedly closed and opened, the polarities of the AC power supply voltage when the relay contacts are closed may be alternated between positive and negative.

According to the above configuration, it is possible to suppress deformation (generation of unevenness) of the relay contact and avoid a problem that the relay contact is in a locked state.

Since the electric device according to the present invention includes the relay contact and the relay control device, the above-mentioned effects can be obtained.

According to the present invention, since the relay contacts can be repeatedly opened without causing an arc discharge, deterioration of the relay contacts can be suppressed.

It is a block diagram which shows the structure of the relay control device which concerns on embodiment. It is a timing chart which shows the operation (when the relay contact is opened) of the relay control device which concerns on embodiment. It is explanatory drawing which shows the zero cross pulse (ZP2). It is a flowchart which shows the generation process (when the relay contact is opened) of the relay control signal which concerns on embodiment. It is a timing chart which shows the operation (when arc discharge occurs) of the relay control device which concerns on embodiment. It is a timing chart which shows the operation (when the relay contact is closed) of the relay control device which concerns on embodiment. It is explanatory drawing which shows the zero cross pulse (ZP4). It is a flowchart which shows the generation process (when the relay contact is closed) of the relay control signal which concerns on embodiment. It is a timing chart which shows the operation of the relay control device which concerns on embodiment (when the relay contact is repeatedly closed and opened).

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 9. FIG. 1 is a block diagram showing a configuration of a relay control device according to an embodiment. FIG. 2 is a timing chart showing the operation of the relay control device according to the embodiment (when the relay contact is opened).

As shown in FIG. 1, the relay control device 10 according to the present embodiment is a device that controls a relay contact 24 provided between the AC power supply 20 and the load 22. The AC power source 20 may be a commercial power source or a power source for private power generation in a facility, a home, a vehicle, or the like. An example of the load 22 is a heater, but the load 22 is not limited to this. For example, it may be a motor that passes a large current. The relay contact 24 is, for example, two contacts included in a mechanical relay (including a hinge type electromagnetic relay, an electromagnetic contactor, and an electromagnetic switch), and a state in which the two contacts of the relay contact 24 are in contact with each other is a relay contact. The state in which the relay contact 24 is closed and the state in which the two contacts of the relay contact 24 are separated from each other are defined as the state in which the relay contact 24 is open. The voltage between the relay contacts (between the two contacts) is Vs.

The relay control device 10 includes a zero-cross signal generation unit 15, a relay contact signal generation unit 16, and a control unit 17. The zero-cross signal generation unit 15 is connected in parallel with the AC power supply 20 to generate a zero-cross signal Sp corresponding to the zero-cross of the AC power supply voltage. The relay contact signal generation unit 16 is connected in parallel with the load 22 and generates a relay contact signal Sk indicating an electrical state between the relay contacts.

The control unit 17 is, for example, a microcomputer including a processor and a memory, generates a relay control signal Sc using a zero cross signal Sp and a relay contact signal Sk, and outputs the relay control signal Sc to the relay contact drive unit 18. The relay contact drive unit 18 receives the relay control signal Sc and drives (closes and opens) the relay contact 24.

The electric device 30 according to the present embodiment includes a relay contact 24, a relay contact drive unit 18, a relay control device 10, and a load 22. The electric device 30 is, for example, a toaster, a humidifier, an electric kettle, a kettle, and the like, but is not limited thereto.

As shown in FIG. 2, the AC power supply 20 is, for example, an AC power supply having a voltage of 100 V and a frequency of 60 Hz, and has a period Th of the AC power supply voltage Pw of 16.6 [ms]. The zero-cross signal Sp in FIG. 2 includes a zero-cross pulse ZP1 corresponding to the −180 ° phase of the AC power supply voltage Pw and a zero-cross pulse ZP2 corresponding to the 0 ° phase of the AC power supply voltage Pw.

For the zero cross pulse ZP1, it falls at time t0 and becomes active (Low), and after the time t1 (zero cross timing) when the AC power supply voltage Pw zero crosses in the −180 ° phase, it rises at time t2 and becomes inactive (High). It becomes.

The relay contact signal Sk is a signal for detecting the current between the relay contacts (between the two contacts of the relay contact 24), and when the relay contact 24 is closed and the current flows through the relay contact 24, it falls and becomes inactive (Low). When the relay contact 24 opens and the current of the relay contact 24 becomes 0, the relay contact 24 rises and becomes active (High).

The relay contact signal generation unit 16 is a relay contact when the relay contact 24 is closed and the current of the relay contact 24 momentarily becomes 0 at the timing when the direction of the current of the relay contact 24 changes. The signal Sk is configured to be inactive (ie, maintain Low). In the following, the timing at which the relay contact signal Sk rises and becomes active (High) is defined as the time tx.

The relay control signal Sc rises after the delay time Tp elapses from the time t0 and becomes active (High). Since the relay contact drive unit 18 drives the relay contact 24 in response to the rise (activation) of the relay control signal Sc, the timing at which the relay contact 24 actually opens is determined by the delay time Tp.

FIG. 3 is an explanatory diagram showing a zero cross pulse (ZP2). Regarding the zero cross pulse ZP2, it falls at time t3 and becomes active (Low), and after the time t4 (zero cross timing) when the AC power supply voltage Pw zero crosses at 0 ° phase, it rises at time t9 and becomes inactive (High). Become.

As shown in FIG. 3, the time t5, t6, t7, and t8 are set between the time t4 and the time t9. With the width of the zero cross pulse as Tw, t4 = t3 + Tw / 2, t6 = t3 + Ti, t8 = t3 + Tj, t5 is the time after t4 and before t6, and t7 is the time after t6 and before t8. be. In the embodiment, time t5 or earlier is defined as period Ta, time t5 to t6 is defined as period Tb, time t6 to t8 is defined as period Ts, time t8 to t9 is defined as period Tc, and time t9 or later is defined as period Td.

For example, if Ti = 0.55 × Tw and Tj = 0.60 × Tw, the period Ts is 0.05 × Tw. When Th = 16.6 [ms], Tw = 800 [μs], and time t7 are intermediate times between time t6 and time t8, t6 = t4 + 40 [μs], t7 = t4 + 60 [μs], t8 = t4 + 80 [ μs], Ts = 40 [μs].

If the time tx is included in the period Ta and the opening timing of the relay contact 24 is significantly deviated in the advancing direction, an arc discharge may occur in the relay contact 24. When the time tx is included in the period Tb, the arc discharge does not occur, but it deviates from the target period Ts in the traveling direction. When the time tx is included in the period Tc, the arc discharge does not occur, but it deviates from the target period Ts in the lagging direction. At time t9, arc discharge does not occur, but when time tx is included in the period Td (when the opening timing of the relay contact 24 is significantly deviated in the delay direction), arc discharge may occur.

Therefore, when the time tx is included in the period Ta, the period Tb, the period Tc, and the period Td, the delay time Tp of the relay control signal Sc is corrected when the relay contact 24 is opened next time, and the time tx is the period Ts. If it is included in, the delay time Tp is not corrected the next time the relay contact 24 is opened.

FIG. 4 is a flowchart showing a relay control signal generation process (when the relay contact is opened) according to the embodiment. The control unit 17 performs the steps of steps S1 to S12 in FIG. In step S1, the time tx (previous tx) and the delay time Tp (previous Tp) when the relay contact 24 was opened last time are read, and in step S2, it is determined whether or not the previous tx is before the time t5. do. If YES (time tx is included in the period Ta) in step S2, the process proceeds to step S3, and the relay control signal Sc is set to a value longer than the previous Tp by the correction value Ua (for example, several tens of microseconds) as the current Tp. To generate.

If NO in step S2, the process proceeds to step S4, and it is determined whether or not the previous tx is before the time t6. If YES (time tx is included in the period Tb) in step S4, the process proceeds to step S5, and the relay control signal Sc is set as the current Tp with a correction value Ub (for example, several microseconds) longer than the previous Tp. Generate.

If NO in step S4, the process proceeds to step S6, and it is determined whether or not the previous tx is before the time t8. If YES in step S6 (time tx is included in the period Ts), the process proceeds to step S7, and the relay control signal Sc is generated with the same value as the previous Tp as the current Tp.

If NO in step S6, the process proceeds to step S8, and it is determined whether or not the previous tx is before the time t9. If YES (time tx is included in the period Tc) in step S8, the process proceeds to step S9, and the relay control signal Sc is set as the current Tp with a correction value Uc (for example, several microseconds) shorter than the previous Tp. Generate.

If NO (time tx is included in the period Td) in step S8, the process proceeds to step S10, and the relay control signal is set to a value shorter by the correction value Ud (for example, several tens of microseconds) than the previous Tp as the current Tp. Generate Sc.

The correction values Ua, Ub, Uc, and Ud may be values determined according to the width Tw of the zero cross pulse, may be a predetermined constant value, and Ua> Ub, Ud> Uc.

After steps S3, S5, S7, S9, and S10, the current time tx is detected in step S11, and the current time tx and the current delay time Tp are stored in step S12. The process of FIG. 4 may be performed with each time as a time lag with the time t0.

FIG. 5 is a timing chart showing the operation of the relay control device according to the embodiment (when arc discharge occurs). When NO in step S8 of FIG. 4 (when the time tx is included in the period Td), as shown in FIG. 5, an arc discharge may occur when the relay contact 24 is opened, and when an arc discharge occurs. Although the contact 24 is structurally open, the relay contact signal Sk remains inactive (Low). Then, the arc discharge continues for about half a cycle, and the relay contact signal Sk becomes active (High) at the timing when the AC power supply voltage Pw approaches 0 and the arc discharge is eliminated. That is, the time tx (rise of the relay contact signal Sk) when the arc discharge occurs is delayed by about half a cycle from the time tx when the arc discharge does not occur, so that the occurrence of the arc discharge can be detected. can.

However, when an arc discharge occurs as shown in FIG. 5, it is not possible to grasp how much the timing at which the relay contact 24 is structurally opened is delayed from the time t9. Therefore, in step S10 of FIG. 4, the correction value Ud is set. It is desirable that the value is sufficiently larger than the correction value Uc (for example, 10 times or more the correction value Uc).

As described above, the control unit 17 uses the information (previous time tx) obtained from the relay contact signal Sk when the relay contact 24 was previously opened, and is desired for the zero cross timing of the AC power supply voltage Pw. A relay control signal Sc is generated so that the relay contact 24 opens at the delayed timing. As a result, deterioration of the relay contact 24 due to arc discharge can be suppressed. The desired delay timing is the timing (period Ts) from time t6 to time t8 at which arc discharge does not occur at the relay contact 24, and the delay amount with respect to the zero cross timing (t4) immediately after the activation of the relay control signal Sc is, for example. , It is less than 1% of the period Th of the AC power supply voltage Pw. When the time tx deviates from the target period Ts, the time tx can be returned (converged) to the period Ts by performing the series of steps of FIG. 4 once or more.

In at least one of steps S5, S9, and S10 in FIG. 4, the current Tp may be determined so that the current time tx matches the time t7 (median value of the period Ts).

Further, in the embodiment, since the relay contact signal Sk is configured to maintain a constant level (Low) regardless of the value of the AC power supply voltage Pw during the period when the relay contact 24 is closed, the control unit 17 Can easily and accurately detect the time tx.

FIG. 6 is a timing chart showing the operation of the relay control device according to the embodiment (when the relay contact is closed). The zero-cross signal Sp in FIG. 6 includes a zero-cross pulse ZP3 corresponding to the −180 ° phase of the AC power supply voltage Pw and a zero-cross pulse ZP4 corresponding to the 0 ° phase of the AC power supply voltage Pw. For the zero cross pulse ZP3, it falls at time t10 and becomes active (Low), and after the time t11 (zero cross timing) when the AC power supply voltage Pw zero crosses in the −180 ° phase, it rises at time t12 and becomes inactive (High). It becomes. In the following, the timing at which the relay contact signal Sk falls and becomes inactive (Low) is set as the time ty.

The relay control signal Sc falls after the delay time Tq has elapsed from the time t10, and becomes inactive (Low). Since the relay contact drive unit 18 drives the relay contact 24 in response to the fall (deactivation) of the relay control signal Sc, the timing at which the relay contact 24 actually closes is determined by the delay time Tq.

FIG. 7 is an explanatory diagram showing a zero cross pulse (ZP4). Regarding the zero cross pulse ZP4, it falls at time t13 and becomes active (Low), and after the time t16 (zero cross timing) at which the AC power supply voltage Pw zero crosses at 0 ° phase, it rises at time t17 and becomes inactive (High). Become.

As shown in FIG. 7, the time t14 to t16 is set between the time t13 and the time t17. The width of the zero cross pulse is Tw, for example, time t14 = t13 + 0.3 × Tw, time t15 = t13 + 0.4 × Tw, t16 = t13 + Tw / 2. In the embodiment, the period before time t14 is defined as the period Te, the times t14 to t16 are defined as the period Tk, and the period after the time t16 is defined as the period Tf.

When the time ty is included in the period Te, it deviates from the target period Tk in the traveling direction. When the time ty is included in the period Tf, it deviates from the target period Tk in the lagging direction. Therefore, when the time ty is included in the period Te · Tf, the delay time Tq of the relay control signal Sc is corrected when the relay contact 24 is closed next time, and when the time ty is included in the period Tk, the next time. The delay time Tq is not corrected when the relay contact 24 is closed.

FIG. 8 is a flowchart showing a relay control signal generation process (when the relay contact is closed) according to the embodiment. The control unit 17 performs the steps of steps S101 to S108 in FIG. In step S101, the time ty (previous ty) and the delay time Tq (previous Tq) when the relay contact 24 was opened last time are read, and in step S102, it is determined whether or not the previous ty is before the time t14. do.

If YES (time ty is included in the period Te) in step S102, the process proceeds to step S103, and the relay control signal Sc is set as the current Tq with a value longer than the previous Tq by the correction value Ue (for example, several microseconds). Generate.

If NO in step S102, the process proceeds to step S104, and it is determined whether or not the previous ty is before the time t16. If YES (time ty is included in the period Tk) in step S104, the process proceeds to step S105, and the relay control signal Sc is generated with the same value as the previous Tq as the current Tq.

If NO (time ty is included in the period Tf) in step S104, the process proceeds to step S106, and the relay control signal Sc is set to a value shorter by the correction value Uf (for example, several microseconds) than the previous Tq as the current Tq. To generate.

After steps S103, S105, and S106, the current time ty is detected in step S107, and the current time ty and the current delay time Tq are stored in step S108.

As described above, the control unit 17 uses the information (previous time ty) obtained from the relay contact signal Sk when the relay contact 24 was previously closed to advance the desired advance with respect to the zero cross timing of the AC power supply voltage. A relay control signal Sc is generated so that the relay contact 24 closes at the timing (prior to the time t16, preferably the period Tk). As a result, the bounce period BT when closing the relay contact 24 is a period in which the AC power supply voltage Pw approaches 0, and the arc discharge due to the bounce of the relay contact 24 can be suppressed.

In at least one of steps S103 and S106 of FIG. 8, the current Tq may be determined so that the current time ty matches the time t15 (median value of the period Tk).

FIG. 9 is a timing chart showing the operation of the relay control device according to the embodiment (when the relay contacts are repeatedly closed and opened). In A of FIG. 9, when the relay contact 24 is closed at time ty1, then opened at time tx1, then closed at time ty2, and then opened at time ty2, the AC power supply voltage Pw at time ty1 is a negative value and time. The AC power supply voltage Pw at tx1 is a positive value, the AC power supply voltage Pw at time ty2 is a positive value, and the AC power supply voltage Pw at time tx2 is a negative value. Further, in B of FIG. 9, the AC power supply voltage Pw at time ty1 is a positive value, the AC power supply voltage Pw at time tx1 is a negative value, the AC power supply voltage Pw at time ty2 is a negative value, and the time tx2. The AC power supply voltage Pw of is a positive value.

In this way, when the relay contact 24 repeatedly closes and opens, the polarity of the AC power supply voltage Pw differs between the timing at which the relay contact 24 closes and the timing at which it opens next, and the AC power supply voltage Pw when the relay contact 24 closes. By alternating the positive and negative voltages of the relay contacts 24, deformation (generation of unevenness) of the relay contact 24 can be suppressed.

If the polarity of the AC power supply voltage Pw when closing the relay contact 24 is the same, or the polarity of the AC power supply voltage Pw when opening the relay contact 24 is the same, one contact of the relay contact 24 (melting). The side) is concave and the other contact (attachment side) is convex, which may cause a problem that the relay contact 24 is locked.

Each of the above embodiments is for purposes of illustration and illustration, not for limitation. Based on these examples and explanations, it will be apparent to those skilled in the art that many variants are possible.

10 Relay control device 15 Zero cross signal generator 16 Relay contact signal generator 17 Control unit 18 Relay contact drive unit 20 AC power supply 22 Load 24 Relay contact 30 Electrical equipment Sp Zero cross signal Sk Relay contact signal Sc Relay control signal t4 t16 Zero cross timing

Claims (6)

A zero-cross signal generator that generates a zero-cross signal according to the zero-cross of the AC power supply voltage, a relay contact signal generator that generates a relay contact signal that indicates the electrical state between the relay contacts, and a control unit that generates a relay control signal. It is a relay control device equipped with
The relay contact signal has the same signal level during the period when the relay contact is closed and the signal level during the period when the relay contact is open and arc discharge occurs.
The control unit uses the information obtained from the relay contact signal and the zero-cross signal when the relay contact was previously opened so that the relay contact opens at a desired delay timing with respect to the zero-cross timing of the AC power supply voltage. A relay control device characterized by generating various relay control signals. The relay control device according to claim 1, wherein the relay contact signal maintains the same level regardless of the value of the AC power supply voltage during the period when the relay contact is closed. Prior Symbol controller, using said information obtained from the relay contact signal when the relay contact is previously closed, the AC power supply voltage desired advances the relay contacts at a timing close such relays respect to the zero-cross timing of The relay control device according to claim 1 or 2, which generates a control signal. The relay control device according to any one of claims 1 to 3, wherein when the relay contact is closed and opened, the polarity of the AC power supply voltage differs depending on the timing at which the relay contact closes and the timing at which the relay contact opens next. The relay control device according to claim 4, wherein when the relay contacts are repeatedly closed and opened, the polarities of the AC power supply voltage when the relay contacts are closed alternate between positive and negative. The electric device provided with the relay contact and the relay control device according to any one of claims 1 to 5.

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