JPS5946033B2 - polyphase multiplier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a time-sharing polyphase multiplier that calculates the sum of the products of each phase of two sets of polyphase electrical quantities in a polyphase AC circuit.

Recently, time-sharing multipliers have been put into practical use not only for multiphase AC circuits but also for general multiplication purposes.

The basic configuration of a time-sharing multiplier used for general multiplication is as follows. Figure 1 shows xxy=z (where y=
-1 to 0 to +1), an inverting amplifier REV consisting of a resistor and an operational amplifier and a resistor R1 are connected in series to the input terminal P1 that supplies the voltage x, and a resistor R2 and a switching The elements S are connected in series and connected in parallel, and the resistance value of the resistor R1 is set to 2, which is twice the resistance value rv of the resistor R2. On the other hand, the input terminal P2 that supplies the voltage y is connected to the (→ terminal) of the comparator amplifier COM, and the output terminal of the triangular wave oscillator TOS is connected to the terminal of the comparator amplifier COM (1). It is connected to the operation input terminal of S, and is configured to close the switching element S when the output of the comparator amplifier COM is positive, and open the switching element S when it is negative.The target to which this multiplier is applied Therefore, y=-1~0~+1
It is necessary to determine the coefficient of X so that In addition, an operational amplifier OPA that synthesizes the input current and converts it into a voltage and a smoothing capacitor C are connected in parallel to the connection point between the resistor R1 and the switching element S, and the output terminal of this parallel circuit is connected to the multiplier output terminal. Connect to P3. In the time division multiplier configured in this way, when a voltage /
2 flows. In addition, the other input terminal P2 receives the other input voltage y(
2a) is supplied and input to the ←) input terminal of the comparator amplifier COM. In addition, the triangular wave reference voltage (Fig. 2a) is connected to the input terminal of the comparison amplifier ℃OM and the triangular wave oscillator TOS.
is supplied from the output terminal of Here, when the input voltage y is smaller than the triangular wave reference voltage, the comparator amplifier CO
Since the output of M becomes positive and the switching element S is in a closed circuit state only during the period when this positive output signal is supplied to the switching element S, the current 12 = x/r flowing through the resistor R2 is as shown in Figure 2 b. It pulsates. In this case, the duty cycle of the pulsating current 12 is 100% at time t1 of y-1, y=
At time T2 of o, it is 50%, and at time T3 of y=+1, it is O%, and the peak value of current 12 is x/r, which corresponds to twice the peak value of current 11 x/2r. Therefore,
The composite current 11+I2 of current 11 and current 12 is shown in Figure 2c.
This combined current 11+I2 is supplied to the operational amplifier 0PA and converted into a voltage.If the smoothing capacitor C is not connected, the output terminal of the operational amplifier 0PA will have the waveform shown in Figure 2d. Pulsating voltage occurs.
However, since the smoothing capacitor C is connected in parallel to the operational amplifier 0PA, a linear operational output voltage z is generated at the output terminal P3 as shown in FIG. 2e. Each point on this calculation output straight line z indicates the multiplication output z of y and x corresponding to that point. A conventional time-sharing type multiphase multiplier, for example, a three-phase multiplier, is configured as shown in FIG. 3 by combining three sets of time-sharing multipliers configured as described above.

When this three-phase multiplier multiplies two sets of three-phase electric quantities for each phase in a three-phase AC circuit and calculates the sum of the multiplication results, for example, the current of each phase of the alternating current machine shown in Fig. 4 is used. 1u
, Iv, Iw and the electromotive force Eu, Ev, Ew of each phase. Instantaneous power P = IuEu + Iv
This is used when multiplying Ev+IwEw as shown in the block diagram of FIG. 5 to calculate the total output P. That is, the conventional three-phase multiplier shown in FIG.
An inverting amplifier REV and a resistor R1 are connected in series to each of the resistors ! and switching element S are connected in parallel, and the resistance value of resistor R1 is set to the resistance value r of resistor R2.
2r, which is twice that of . In addition, the input terminals D, E, and F that supply the other three-phase electric quantities for multiplication are connected to the (c) input terminals of the comparator amplifiers COM provided for each of the three phases, and the (c) input terminals of each comparator amplifier COM are g) Connect the output terminals of the triangular wave oscillator TOS provided in common to the three phases to the input terminals, and connect the output terminals of each comparator amplifier COM to the respective operation signal input terminals A, b,
Connect to c. Note that the resistance values of the resistors R, R2 are set depending on the object to be multiplied so that the inputs supplied to the input terminals D, E, and F are in the range of -1 to 0 to +1. In addition, the output side contacts of the switching elements S of each of the three phases are connected together, the operational amplifier 0PA and the smoothing capacitor C are connected in parallel to this connection point, and these output side terminals are connected to the multiplication output terminal. P
Connect to. For example, the currents 1u, Iv, I of the alternating current machine shown in FIG.
The sum of the products of w and the electromotive forces Eu, Ev, and Ew for each phase, that is, the three-phase instantaneous power P=IuEu+IvEv+Iw
When calculating Ew, currents 1u, v, and W are converted into voltages by a current/voltage converter (not shown) and inputted to one input terminal A, B, and C, respectively, and the other input terminal D is , E, and F by inputting electromotive forces Eu, Ev, and EW, respectively.

By supplying the input in this way, the multiplier operates in exactly the same way as the multiplier shown in FIG.
v, Iw and the electromotive forces Eu, Ev, Ew are respectively multiplied and added by the operational amplifier 0PA, resulting in three-phase instantaneous power P.
−UEu+IvEv+IwEw is obtained from the output terminal P. However, the conventional time-sharing type three-phase multiplier constructed as described above not only has a complicated circuit and is troublesome to inspect, but also has the drawback of increasing manufacturing costs.

Therefore, as a result of intensive research and efforts, the inventor found that in the conventional three-phase multiplier shown in Fig. 3, the three-phase electrical quantity supplied to the single-power input terminals A, B, and C is equal to the zero-phase amount. In the case of a three-phase balanced input that does not include the current 1 flowing through the resistor R2
Since the current 2 flows intermittently due to the opening and closing of the switching element S, it does not become zero even if the three phases are added, but the current 1 flowing through the resistor R1 via the inverting amplifier REV is reduced to 3 by the operational amplifier 0PA.
When the phase components are added, each current is in a three-phase equilibrium state, so the following equation 11 (u) + i1 (v) + I, (
We found that the sum is always zero as shown by w) = 0, and found that this allows the circuit to be simplified as follows.

In other words, if one of the two sets of three-phase electrical quantities to be multiplied does not include a zero-phase component, an inverting amplifier and Even if the series resistor connected in series is removed, the exact same effect can be achieved, which not only simplifies the circuit and eliminates the above-mentioned difficulties at once, but also further improves accuracy. I understand. Therefore, the general object of the present invention is to provide a time-sharing method for calculating the sum of the products of each phase of two sets of polyphase electrical quantities in which at least one polyphase electrical quantity does not include a zero-phase component. It is an object of the present invention to provide a polyphase multiplier which can be manufactured at a low cost by simplifying the circuit and can obtain a highly accurate output.

In order to achieve this objective, the present invention uses a time-sharing polyphase multiplication method that calculates the sum of products for each phase of two sets of polyphase electrical quantities in which at least one of the polyphase electrical quantities does not include a zero-phase component. A switching element connected in series between each set of first polyphase input terminals and the input terminal of the filter circuit, a comparator amplifier connected respectively to the second polyphase input terminal, and An oscillator that supplies a reference signal is provided at the input end of the comparison amplifier, and the output signal from each comparison amplifier is configured to open and close the switching elements of each phase, and is input to the first polyphase input terminal. It is characterized in that a multiphase electrical quantity that does not include a zero phase component is selected as the multiphase electrical quantity.

In the polyphase multiplier described above, it is preferable that the oscillator connected to the input terminal of the comparator amplifier be constituted by a triangular wave oscillator that generates a triangular wave reference voltage.

Next, embodiments of the polyphase multiplier according to the present invention will be described in detail below with reference to the accompanying drawings. Figure 6 shows the electric circuit of a three-phase multiplier, in which input terminals A, B, and C that supply one three-phase quantity of electricity are connected to resistors 10a and 10b, respectively.
, 10c to the single-power contacts of the switching elements 12a, 12b, 12c, and the switching elements 12a, 12b, 10c.
The external force contacts 12c are connected for three phases at once, and the operational amplifier 14 and smoothing capacitor 16 are connected in parallel to this connection point, and this output side terminal is connected to the multiplier output terminal P. Resistors 10a to 10c, operational amplifier 14, and smoothing capacitor 1
6 constitutes a three-input addition low-pass filter. In addition, the input terminals D, E, and F for supplying the other three-phase electric quantity are connected to the respective input terminals of the comparison amplifiers 18a, 18b, and 18c for each of the three phases, and are also provided in common for the three phases. The output terminal of the triangular wave oscillator 20 is connected to the comparison amplifier 18a, 1
8b, 18c, and further connected to the respective output terminals of the comparison amplifiers 18a, 18b, 18c to the respective operation signal input terminals A, b, c of the switching elements 12a, 12b, 12c. do. When compared with the conventional three-phase multiplier shown in FIG. 3, the multiplier of the present invention constructed in this manner is completely the same except that the inverting amplifier and its series resistance are omitted.

Therefore, if the three-phase quantity of electricity supplied to input terminals A, B, and C of one power is a balanced three-phase quantity of electricity that does not include the zero-phase component,
For the reasons stated above, it performs exactly the same function as the conventional three-phase multiplier shown in FIG. For example, the detected values 1u, , Iw of the three-phase balanced current of the AC machine shown in Fig. 4 are input to one input terminal A, B.
, C, and the electromotive force detection values Eu, Ev, Ew of each phase are supplied to the other input terminals D, E, F, the product of each phase of the input three-phase electric quantities A three-phase instantaneous power P expressed by the sum of P=IuEu+IvEv+IwEw can be taken out from the output terminal P.

In addition, in the above embodiment, the calculation of the three-phase instantaneous power P was explained, but the following formula 1112=Iu2+Iv2+
The absolute value 111 of the three-phase current can also be obtained by performing the calculation shown in Iw2.

Furthermore, the magnetic flux ΦUv, Φ between each phase of the alternating current machine shown in Fig. 7
Vw, (1) from Wu) following formula 1012 = ΦUv2 + ΦV
By performing the calculation shown in w2+ΦWv2, the absolute value 1Φl of the three-phase magnetic flux can be obtained, and the following formula TOIwOuv
The torque T can also be determined by performing the calculation shown in +Iu(1)Vw+Iv(1)Wu.

According to the present invention, a time-sharing polyphase multiplier that calculates the sum of the products of each phase of two sets of polyphase electrical quantities in which at least one of the polyphase electrical quantities does not include a zero-phase component can be simplified. The configuration provides many advantages such as being able to manufacture at low cost and improving accuracy.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Fig. 1 is an electric circuit diagram showing the basic configuration of a general time-sharing multiplier, Fig. 2 is a waveform diagram showing the action of the time-sharing multiplier shown in Fig. 1, and Fig. 3 is a conventional time-sharing multiplier. An electric circuit diagram showing the configuration of a three-phase multiplier, Fig. 4 is an explanatory diagram showing two sets of three-phase electric quantities of an AC machine multiplied by a three-phase multiplier, and Fig. 5 shows the three-phase multiplication shown in Fig. 3. FIG. 6 is an electric circuit diagram showing an embodiment of the multiphase multiplier according to the present invention, and FIG. It is an explanatory view showing three-phase electric quantity. 10a, 10b, 10c...Series resistance, 12a
, 12b, 12c...Switching element, 14...
...Operation amplifier, 16...Smoothing capacitor, 1
8a, 18b, 18c... Comparison amplifier, 20.
...Triangle wave oscillator.

Claims (1)

[Claims] 1. At least one multiphase electrical quantity does not include a zero phase component. 2.
In a time-sharing polyphase multiplier that calculates the sum of the products of each phase of each phase of a set of polyphase electrical quantities, between each phase of the first polyphase input terminal and the input terminal of the filter circuit. A switching element connected in series to each of the second polyphase input terminals, a comparison amplifier connected to each of the second polyphase input terminals, and an oscillator that supplies a reference signal to the input terminals of these comparison amplifiers are provided, and an output from each comparison amplifier is provided. The switching element of each phase is configured to be opened and closed by a signal, and the multiphase electrical quantity that does not include a zero phase component is selected as the multiphase electrical quantity input to the first multiphase input terminal. A polyphase multiplier. 2. In the polyphase multiplier according to claim 1,
The oscillator connected to the input terminal of the comparison amplifier is a polyphase multiplier consisting of a triangular wave oscillator that generates a triangular wave reference voltage.